ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

Language
Number of Hits per Page
Default Sort Criterion
Default Sort Ordering
Size of Search History
Default Email Address
Default Export Format
Default Export Encoding
Facet list arrangement
Maximum number of values per filter
Auto Completion
Topics (search only within journals and journal articles that belong to one or more of the selected topics)
Feed Format
Maximum Number of Items per Feed
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • Articles  (17,655,351)
  • Latest Papers from Table of Contents or Articles in Press  (17,655,351)
Collection
  • Articles  (17,655,351)
Source
Years
  • 1
    Publication Date: 2024
    Description: 〈p〉〈em〉〈span〉This study delves into the management of electronic waste (e-waste) stemming from the disposal of personal electronic items and mobile phones, primarily in response to the remarkable surge in the utilization of these devices within the Hassan city populace in recent years. The principal objectives revolved around investigating the existing disposal methods for electronic devices including mobile phones and collecting fundamental data concerning their disposal practices within the geographical confines of Hassan city of Karnataka State. Additionally, an endeavor was undertaken to gauge the level of awareness among respondents regarding the potential hazards posed by e-waste. It was observed that a significant proportion of the Hassan population typically retains especially electronic devices is cell phones, once these devices become outdated and obsolete. Among the prevalent disposal methods, the most widespread approach involves selling these gadgets to scrap dealers or junk shops, whereas recycling practices remain relatively underutilized. Notably, a mere minority of individuals engage in recycling activities. An intriguing revelation emerged, with 65% of respondents expressing concern about the adverse repercussions of improper e-waste disposal on human health and the environment. Astonishingly, all respondents admitted to having no knowledge of the fate of their discarded electronic devices. Based on the findings gleaned from this survey, it is strongly recommended that a comprehensive review be conducted on the overarching management of e-waste stemming from this electronic waste including mobile phones, gadgets in the Hassan city of Karnataka State. The purpose of these surveys and data collection endeavors is to approximate the volume of e-waste generated through the disposal of these devices. This information is envisioned to assist stakeholders and government agencies in formulating effective and efficient legislation and policies for the proficient management of e-waste〈/span〉〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2024
    Description: 〈p〉〈em〉Indian Railroads is one of the largest railroad systems in the World. The Indian railway system has grown significantly over the years, as seen by the massive construction of its railroads; nonetheless, some accidents are caused by fractures in the railway track. Splits may occur because of the track's expansion or contraction brought on by seasonal variations. This study proposes a crack monitoring vehicle that employs an ultrasonic sensor to detect fractures on railway tracks and uses an Arduino Uno to facilitate the GSM and GPS module to send an SMS to the testing station, thereby mitigating the problems caused by these cracks. This intelligent system works like a remote monitoring system which gives an alert to stop the passage of trains in that path. The proposed model involves the use of Arduino, ultrasonic sensor, buzzer, GSM module, and GPS module.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2024
    Description: The applicability of the Gravity Recovery and Climate Experiment (GRACE) level 1B range-rate data for detecting gravity changes under the influence of strong earthquakes (M6.0-6.9) has been investigated. The most common product of the GRACE mission is the level 2, science data, as the spherical harmonic Stokes’ coefficients of the geopotential. These coefficients have been generated from Level 1B data which has resulted in missing some information during the smoothing process. In this study, the GRACE level 1B K-band range-rate measurements over three selected cells in Iran were analyzed, including two cells containing the epicenters of the Boroujerd earthquake (6.1 Mw) and the Zarand earthquake (6.4 Mw), which occurred on March 31, 2006, and February 22, 2005, respectively, and one cell far enough from those two cells. Additionally, the range-rate time series attributed to Iran's main catchments containing the above-mentioned zones have been extracted to distinguish between the effects of earthquakes and hydrology on the range-rate time series. Besides, the impact of factors other than earthquakes such as tide and non-gravitational accelerations acting on the GRACE satellites has been corrected. To better explore the extracted signals, their details have been derived using the wavelet transforms and the corresponding anomalies have been detected using the boxplot method. The considerable anomalies that have been observed in areas within or close to the earthquakes' epicenters before and after the earthquakes indicate that the GRACE and GRACE Follow-On range-rate time series can be considered as one of the potential precursors of a strong earthquake.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2024
    Description: سپیدایی از فراسنجﻫﺎی کلیدی در ﻣﻄﺎﻟﻌﺎت آب و ﻫﻮاﻳﻲ ﻣﻲﺑﺎﺷﺪ. بررسی آب و هواشناسی سپیدایی می‌تواند ابزاری برای شناخت تغییرات محیطی باشد. ﺳﻨﺠﻨﺪه مودیس سپیدایی سطح زﻣﻴﻦ را ﺑﻄﻮر ﻣﺴﺘﻤﺮ در ﻣﻘﻴﺎﺳﻲ ﺟﻬﺎﻧﻲ و ﺑﺎ ﻗﺪرت ﺗﻔﻜﻴﻚ ﻣﻜﺎﻧﻲ مناسب ﺗﻮﻟﻴﺪ و در دسترس پژوهشگران ﻗﺮار می‌دهد. در این پژوهش جهتِ واکاوی آب و هواشناسی سپیدایی ایران‌، نخست داده‌های فراورده MCD43A4 سنجنده مودیس در محدوده ایران در بازه زمانی 1/1/2001 تا 30/12/2021 با تفکیک مکانی 500 متری و تفکیک زمانی روزانه از وبگاه ناسا برداشت شد. پس از پیش پردازش‌های لازم، میانگین بلندمدت ماهانه، فصلی و سالانه سپیدایی ایران محاسبه گردید. یافته‌ها در مقیاس ماهانه نشان داد که در ماه‌های سرد سال( Jan, Feb, Mar ) که ماه‌های برفپوش ایران شناخته می‌شوند، سپیدایی ایران بیشینه شده و ماه‌های گذار فروکش کرده و سپس در ماه‌های گرم سال (June, July, Aug) به سبب خشکی زمین و افزایش دمای رویه زمین دوباره افزایش می‌یابد. این رفتار دو سویه در مقیاس فصلی نیز آشکار است. بطوری که سپیدایی ایران در فصول زمستان و تابستان بیشینه و در فصول بهار و پاییز (فصول گذار) کمینه می‌باشد. همچنین یافته‌ها گویای آن است که میانگین بلندمدت سپیدایی ایران حدود 5/12 درصد است. با آگاهی از محدود بودن پوشش برفی ایران، پایین بودن سپیدایی ایران طبیعی به نظر می‌رسد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2024
    Description: Evaluating the susceptibility of regional climates to climate change gives a pattern to realistically analyze the probable future climate changes. This paper investigates human influence on variations in precipitation extremes in Iran by evaluating precipitation data provided from 286 rain-gage stations during 1967-2010 and general circulation simulation results of CanESM2 model. This investigation was based on six forcing factors including natural external (volcanic aerosol, solar radiation), anthropogenic and a combination of them, Green House Gases (GHGs), change of land use, and anthropogenic aerosols. Seven precipitation indices namely Rx1day (Annual maximum 1-day precipitation), Rx5day (Annual maximum 5-day precipitation), R10mm (Annual count of days where daily precipitation is more than 10 mm), R20mm (Annual count of days where daily precipitation is more than 20 mm), CDD (Consecutive dry days), CWD (Consecutive wet days), and PRCPTOT (Annual total wet day precipitation) have been analyzed via the optimal fingerprint method. The results revealed that Rx1day, Rx5day and CWD increased, while R10mm, R20mm, CDD, and PRCPTOT decreased among which CDD and Rx1day indices with values of 18.4% and 10.9%, respectively showed significant variations. Furthermore, the obtained results implied that only the effect of anthropogenic forcing with a value of 1.4 was detected and attributed in CDD variations, also ANT caused increase in the return period of a 20-year event by 1.9 year for CDD. Although human-induced forcing factors presented marked trends in some cases, their effects were not generally detected and attributed on the change in the observations, apart from one exception.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2024
    Description: گردوخاک پدیده هواشناسی رایج در مناطق خشک و نیمه خشک جهان است که در اثر عوامل طبیعی یا انسانی ایجاد می‌شود. شناسایی چشمه‌های فعال گردوخاک نخستین گام برای مقابله با آن و کاهش پیامدهای مخرب آن است. برای این منظور از دو شاخص عمق نوری هواویزها (AOD) و اختلاف بهنجار شده پوشش گیاهی (NDVI) از سنجنده MODIS ماهواره Terra برای دو دهه گذشته (2020-2001) استفاده شده است. برای بررسی چشمه‌های فعال هواویز در منطقه مورد مطالعه درصد فراوانی آستانه‌های هواویزها با سه آستانه 0.3، 0.5و 1 مورد بررسی قرار گرفت. بیشینه مقادیر AOD مربوط به فصول بهار و تابستان است. بطور کلی شش کانون اصلی هواویزها بر اساس مقادیر AOD و شاخص FoO برای منطقه غرب آسیا قابل تشخیص است. این کانون‌های هواویز در پهنه اقلیمی بیابانی گرم و خشک (BWh) دیده می‌شوند. تنها کانون هووایز موثر در شمال شرقی ایران در پهنه اقلیمی بیابانی خشک و سرد (BWk) در کشور ترکمنستان قرار دارد. بررسی ماتریس ضریب همبستگی هواویزها با پوشش گیاهی نشان ازرابطه معکوس دارد، البته این رابطه بیشتر برای چشمه‌های هواویزها صادق است. فارغ از نقش تعیین کننده ویژگی‌های سطحی در رخداد هواویزها، دو پدیده هواشناسی همانند باد شمال تابستانه و باد 120 روزه سیستان در تشکیل کانون‌هایی با مقادیر AOD بالاتر 0.5 و 1 نقش تعیین کننده‌‌ای دارند.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2024
    Description: بازتابسنجی تداخلی GNSS را میتوان بعنوان یکی دیگر از روشهای سنجش از دور برای پایش رطوبت خاک بصورت پیوسته و البته در مقیاس محلی در نظر گرفت که در وضعیتهای مختلف جوی مانند شرایط بارانی و مه آلود و در شرایط متفاوت نور و روشنایی مانند روز و شب قابل اجرا است. سیگنالهای بازتابی از سطح زمین توسط آنتنهای GNSS قابل دریافت است. تغییرات در رطوبت خاک باعث تغییر در مقدار مؤلفه نسبت سیگنال به نویز SNRسیگنال‌های بازتابی میشود. با تجزیه و تحلیل سیگنالهای بازتابی، میتوان به اطلاعات مفیدی در مورد سطح بازتاب دست یافت. SNR به شدت به رطوبت خاک وابسته است. در این تحقیق داده های ایستگاه P038 در منطقه نیومکزیکو مورد استفاده قرار میگیرد. بدینصورت که از سیگنالهای چندمسیری برای برآورد تغییرات رطوبت خاک در طول چهار سال، از 2017 تا 2020 استفاده میشود. طبق برآورد انجام شده سطح محتوای حجمی آب در سال 2017، برابر 8/88 میباشد، که در سال 2018 به 11/74 افزایش مییابد. سپس اندکی کاهش یافته و در سال 2019 به 10/88 رسیده و نهایتاً در سال 2020 به 12/49 افزایش مییابد. در این مقاله کارائی مدل شبکه عصبی LSTM در پیش بینی سری زمانی رطوبت حجمی خاک بدست آمده از تداخل سیگنالهای بازتابی GNSS مورد ارزیابی قرار می‌گیرد. آموزش مدل با استفاده از 80 درصد مشاهدات ایستگاه انجام میگیرد. با به روزرسانی وضعیت شبکه با مقادیر مشاهده شده به جای مقادیر پیش بینی شده، مقدار جذر خطای مربعی میانگین از 0/09 به 0/04 کاهش یافته و پیش بینی ها دقیقتر انجام میشوند.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2024
    Description: Abstract Subsurface channels are stratigraphic features in seismic data that can act as reservoirs or conduits for hydrocarbons. However, detecting and characterizing these channels is challenging due to the limitations of seismic resolution and the complexity of the subsurface geology. Seismic inversion is a technique that can enhance the seismic data by transforming the seismic traces into quantitative estimates such as acoustic impedance (AI), which is a key reservoir rock property. AI inversion can help to identify and delineate the subsurface channels by providing more contrast and detail of the channel geometry, fill, and surrounding sediments. Seismic inversion is often challenged by the non-uniqueness, ambiguity, and uncertainty of the inversion results due to noise and band-limited data. This paper uses a fuzzy model-based seismic inversion method that integrates prior information and fuzzy clustering constraints to produce more realistic and reliable AI models. This method assigns data points to multiple clusters with varying degrees of membership, which can capture the overlapping of AI values of different geological formations. The method is applied to the 3D Poseidon seismic data from the Browse Basin, offshore Western Australia, and the results are compared with those of conventional model-based inversion. Since there is no well-data in an interest channel zone, a qualitative evaluation with seismic attributes is performed. The subsurface structures are further interpreted by various seismic attributes. The comparison shows the fuzzy model-based inversion method can improve the resolution, contrast, and stability of the AI models and reveal more detail of the subsurface geology.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2024
    Description: یکی از چالش‌های اصلی در بکارگیری مدل‌های ژئوپتانسیلی جهانی، محاسبه توابع لژاندر وابسته نوع اول بر اساس فرمول-های بازگشتی معمول است. از آنجاییکه اکثر نرم‌افزارهای محاسباتی به طور پیش‌فرض از فرمت «دقت مضاعف» در محاسبات استفاده می‌کنند، یک سوال مهم این است که آیا این سطح دقت برای محاسبه توابع لژاندر وابسته نوع اول و ارزیابی مدل‌های ژئوپتانسیلی کافی است؟ نتایج نشان می‌دهد که محاسبه توابع لژاندر در درجه 2190، معادل بالاترین درجه مدل‌های ژئوپتانسیلی جهانی موجود، حتی با بکارگیری دقت مضاعف، برای عرض‌های کروی در بازه [ʹ33˚78 وʹ20˚56] از دقت کافی برخوردار نیست، که بیشترین کاهش دقت در عرض کروی 60 درجه رخ می‌دهد. همچنین نتایج نشان می‌دهد که در عرض کروی 60 درجه، محاسبه توابع لژاندر در درجات بالاتر از 2029، دچار افت دقت شده و این افت دقت با افزایش درجه تشدید می‌گردد. بر اساس نتایج، محاسبه پتانسیل ثقل و شتاب ثقل تا درجه 2190، به ترتیب در محدوده عرض‌های کروی ازʹ32˚57 تاʹ13˚60 و ازʹ41˚57 تا ʹ13˚60 دچار افت شدید دقت می‌شود. از نتایج ما درمی‌یابیم که حداکثر درجه بسط برای محاسبه دقیق پتانسیل ثقل و شتاب ثقل برای تمام عرض‌های کروی، به ترتیب درجه 2065 و 2071 است. در این تحقیق، ما نشان می‌دهیم که برای محاسبه توابع لژاندر بر اساس روابط بازگشتی و تولید تابعک‌های میدان ثقل بر اساس مدل‌های ژئوپتانسیلی درجات بالای کنونی، نیازمند حفظ «دقت مضاعف طویل» در تمام فرایند محاسباتی هستیم.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2024
    Description: 〈p〉〈em〉Road safety is a critical concern in the modern world, where advancements in technology have made our lives easier but have also given rise to increased traffic hazards and road accidents. The "Car Accident Detector and Informer" project is an innovative system aimed at enhancing road safety by accurately detecting and informing about car accidents in real-time. This project integrates advanced sensors, microcontroller technology, and communication protocols to create an efficient accident detection and notification system. Utilizing GPS and GSM technology for precise location tracking and instant notifications, this system has the potential to reduce emergency response times, save lives, and minimize property damage. This research paper presents a detailed overview of the project, including its objectives, working principles, components, advantages, disadvantages, and prospects.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 11
    Publication Date: 2024
    Description: 〈p〉〈em〉Spatiotemporal data analytics is a dynamic field that seeks to extract valuable information from data that integrates both spatial and temporal dimensions. This article explores the importance of this emerging field and its applications in a variety of fields, including environmental science, public health, and urban planning. Spatiotemporal data analysis addresses important research questions, such as determining event probabilities, understanding change patterns, identifying associations between events, and predicting events Future. However, this comes with many challenges, including managing large datasets, ensuring data quality, dealing with spatial and temporal autocorrelation, and more. To address these challenges, proposed solutions include data reduction and sampling, dimensionality reduction, data compression, use of spatial and temporal indexes, parallel and distributed processing, data filtering and pre- processing. Furthermore, strategies to handle spatial and temporal autocorrelation include exploratory data analysis, using spatial weight matrices, including spatially lagged variables, and regression models. spatial attribution, cluster analysis, etc for spatial autocorrelation and for temporal autocorrelation, solutions include time series analysis, differencing, ARIMA models, lagged variables, time series decomposition, exponential smoothing, state space modelling, machine learning, cross-validation, and regularization techniques. These approaches provide valuable insights to address the complexity of spatio-temporal data analysis and unlock its potential in various fields.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 12
    Publication Date: 2024
    Description: 〈p〉〈em〉Diamond drilling, a core drilling technique employing diamond-encrusted drill bits, has emerged as a critical method for extracting cylindrical rock samples from diverse geological formations. This article provides an extensive overview of diamond drilling, encompassing its equipment, applications, challenges, and its pivotal role in geological exploration, mining, and construction projects. The versatility of diamond drilling is evident in its adaptability to various rock types, spanning the gamut from soft sedimentary strata to formidable crystalline structures. In mining, it serves as an indispensable tool for assessing the quality, depth, and size of mineral deposits. Likewise, in construction and civil engineering, diamond drilling aids in ascertaining geological conditions for safe and stable foundation design. Environmental considerations are paramount in contemporary drilling practices, with containment measures for drilling fluids to mitigate ecological impacts. Safety precautions are rigorously adhered to, ensuring the well-being of workers and the integrity of drilling operations. Furthermore, core samples extracted through diamond drilling are instrumental in geological investigations. These samples, meticulously analyzed, yield insights into rock composition, mineral content, and geological structures. They inform decisions in resource exploration, mine planning, and construction project management. This review underscores the invaluable contributions of diamond drilling to our understanding of the Earth's subsurface, emphasizing its adaptability, environmental consciousness, and safety. By examining the critical aspects of this technique, this article illuminates the profound impact of diamond drilling on various industries and the scientific community, positioning it as an indispensable tool for unlocking the secrets hidden beneath the Earth's surface.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 13
    Publication Date: 2024
    Description: تعیین لبه و موقعیت افقی ساختارهای زمین‌شناسی یکی از مراحل اساسی در تفسیر داده‌های میدان پتانسیل محسوب می‌گردد. در این مقاله مثبت‌ترین و منفی‌ترین انحنا داده‌های گرانی تجزیه و تحلیل گردیده و فیلتری کارآمدتر با استفاده از نشانگرهای انحنا و ترکیبات آن‌ها برای تشخیص گوشه‌های ساختارها و چشمه‌های مدفون گرانی معرفی و استفاده گردیده است. روش پیشنهادی که فیلتر انحنای هیبریدی مثبت و منفی (یا به اختصار PNH) نامیده می‌شود، مثبت‌ترین و منفی‌ترین انحناها را با تنظیم فرمول و جمع وزنی در یک انحنا ترکیب و از مزایای دو انحنا مثبت و منفی برای بهبود تشخیص لبه داده‌های گرانی استفاده می‌نماید. بدین منظور ابتدا توانایی فیلتر PNH با در نظر گرفتن فرض‌های مختلف چگالی (مثبت، منفی و مثبت-منفی) برای مدل گرانی نسبتا پیچیده مصنوعی حاصل از منشورهای مدفون بدون نوفه و همراه با نوفه تصادفی مورد بررسی قرار گرفته که نتایج به دست آمده بر روی مدل‌های مصنوعی نشان می‌دهد فیلتر انحنای هیبریدی مثبت و منفی، از توانایی نسبتا خوبی برای تشخیص مرزهای افقی ساختارهای مدفون با چگالی و عمق‌های مختلف برخوردار است. همچنین از فیلترهای استاندارد تعیین گوشه مانند، مشتق قائم مرتبه دوم گرانی و فیلتر زاویه تیلت یا کجی برای مقایسه و صحت‌سنجی توانایی فیلترهای نشانگر انحنا بر روی مدل مصنوعی استفاده شده است. در ادامه کیفیت فیلتر پیشنهادی PNH ابتدا بر روی داده‌های واقعی یک معدن طلا واقع در منطقه ویتواترزند (آفریقای جنوبی) و سپس بر روی داده‌های گرانی مربوط به گنبد نمکی آجی‌چای (ایران) مورد بررسی و مطالعه قرار گرفته است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 14
    Publication Date: 2024
    Description: برونداد مدل‌های پیش‌بینی عددی وضع هوا دارای خطا است. جهت اصلاح پیش‌بینی‌های کوتاه مدت (24، 48 و 72 ساعته) دمای بیشینه و کمینه مدل WRF، از یک روش یادگیری ماشین به نام ماشین تعقیب کننده استفاده شد. در این روش با سری زمانی 300 روزه از خطای برونداد مدل و با به کارگیری روش کمترین مربعات طیفی شبه فوریه- سری زمانی، خطای پیش‌بینی‌های مدل WRF برآورد شد. خطای پیش‌بینی‌ها در دوره 01/11/2020 الی 05/03/2023 برای 560 ایستگاه هواشناسی برآورد شد. یکی از نقاط قوت این روش، استفاده از تنها یک متغیر برای کاهش خطای پیش‌بینی‌های است. عملکرد پیش‌بینی مدل WRF بسته به مکان و زمان متفاوت است مثلا نمره مهارت مدل برای دمای بیشینه در ماه سپتامبر نسبت به سایر ماه‌ها کمتر و در مناطق جنوب غربی زاگرس نسبت به سایر مناطق کمتر است، که بعد از اصلاح این وابستگی حذف، و پیش‌بینی در تمام مناطق و زمان‌ها عملکرد یکسانی دارد. نتایج نشان داد نمره مهارت، RMSE و شاخص اطمینان‌پذیری پس از اصلاح خطای مدل به شکل قابل توجهی بهبود می‌یابد. پس از اصلاح خطا، نمره مهارت مدل برای پیش‌بینی دمای بیشینه از 1/0- به 85/0 و برای دمای کمینه از 38/0 به 72/0 می‌رسد. به طور متوسط RMSE برای پیش‌بینی دمای بیشینه از 6 به 2 درجه وبرای دمای کمینه از 5/4 به 3 درجه سلسیوس می‌رسد. پس از اصلاح خطای مدل، تغییرپذیری نمره مهارت پیش‌بینی‌ها کاهش یافته و با کاهش مقدار خطای پیش‌بینی‌ها، قابلیت اطمینان‌پذیری به پیش‌بینی‌های مدل به طور متوسط از 60 درصد به 85 درصد می‌رسد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 15
    Publication Date: 2024
    Description: امواج درونی نقش اساسی در وضعیت هیدرولوژیکی و انرژی اقیانوس‌ها دارد یکی از انواع امواج درونی امواج بادپناه است که در اثر عبور جریان‏های زیرسطحی یا جزرومدی بر روی توپوگرافی بستر دریا به وجود می‏آیند و یکی از عوامل جابجایی لایه‏های همچگالی در زیر آب است. این موضوع باعث تغییر میزان مواد مغذی دریا و چگالی دریا خواهد شد. به همین دلیل شناخت امواج باد پناه در صنایع ماهی‏گیری و نظامی از اهمیت بالایی برخوردار است. در این مقاله با استفاده از ماژول جریان مدل سه بعدی Delft3D به صورت هیدرواستاتیک و غیرهیدرواستاتیک در تنگه هرمز که به دلیل داشتن کم‏عمقی‏های فراوان مستعد تشکیل موج بادپناه می باشد شبیه‏سازی امواج بادپناه انجام شده است و با استفاده از تصویر ماهواره‏ای SAR، داده میدانی و مطالعات پیشین اعتبارسنجی صورت گرفت. نتایج وجود امواج بادپناه در تنگه هرمز را نشان می‎دهند. هر دو مدل هیدرواستاتیک و غیرهیدرواستاتیک توانسته‏اند جهت انتشار و تولید امواج درونی را با تقریب مکانی قابل قبول شبیه‏سازی کنند، با این تفاوت که مدل غیرهیدرواستاتیک دارای مقادیر سرعت جریان بزرگتری می‏باشد، هرچند که نتایج هر دو مدل در رنج 4/0- تا 4/0+ می‏باشد. با این حال می توان گفت حالت هیدرواستاتیک تلاطم‏های بیشتری را نشان می‏دهد و به دلیل استفاده از مختصات عمودی سیگما، لایه ترموکلاین را با دقت بالاتری شبیه‏سازی می‏کند.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 16
    Publication Date: 2024
    Description: Both aeromagnetic and radiometric data was deployed to evaluate the Curie point depth and radiogenic heat production (RHP) of the young granitic regions of Jos plateau. An area of 55 by 110 square kilometers bounded by latitude 9°30' to 10°00' N and longitude 8°30' to 9°30' E of central Nigeria. The magnetic data was subjected to spectral analysis to obtain the curie depth which was subsequently used to evaluate the geothermal gradient and Heat flow for the area. Also, the concentration of radioelements (Potassium, thorium and Uranium) and average density of the in-situ rock was used to estimate the radiogenic heat production at each point where the Curie point was evaluated. The heat flow of the study area ranges from 10 to 165.5 mW/m2 with an average value of 111.00 mW/m2. The regions with anomalous heat flow of 165.5 mW/m2 are around Bowon Dodo, Dan Tsofo, Kadunu, Gimi, Kaura and Zankan of plateau state. The geothermal gradient values range from 5 to 68 °C/Km with an average of 26.16 °C/Km. The radiometric data analysis resulted in radiogenic heat values ranging from 0.4 µWm3 to 6 µW/m3 with average radiogenic heat value of 3.36 µW/m3. Both analyses revealed that regions such as Ataka, Gimi, Jimjim and Pari could be explored for geothermal energy. The high concentration of uranium, thorium and potassium associated with the study area must have arisen from the weathered in-situ granitic basement rocks.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 17
    Publication Date: 2024
    Description: مدل‌های گردش کلی (GCMs) کم و بیش دارای اریبی هستند و یکی از تکنیک‌های مورد استفاده برای کاهش اریبی مدل‌ها در بررسی پیامدهای تغییر اقلیم به‌کارگیری روش‌های تصحیح اریبی است. این مطالعه کارایی پنج روش تصحیح اریبی شامل دو روش نسبت‌گیری و سه روش نگاشت چندک را برای دو متغیر دمای کمینه و بیشینه در 46 ایستگاه همدید ایران طی دوره 1980-2014 با استفاده از مدل EC-Earth3-CC از سری مدل‌های CMIP6 مورد بررسی قرار می‌دهد. نتایج نشان داد برونداد مستقیم مدل EC-Earth3-CC برای هر دو متغیر دمای کمینه و بیشینه در تمامی پهنه‌های اقلیمی ایران و همچنین متوسط اقلیمی کشور دارای اریبی سرد (کم‌برآوردی) است. به‌طور کلی، پس از تصحیح اریبی، مقدار اریبی دو متغیر دمای کمینه و بیشینه به‌شکل قابل توجهی کاهش یافت. روش‌های نسبت‌گیری نسبت به روش‌های نگاشت چندک بهبود بیشتری را در برونداد مستقیم مدل نشان دادند. براساس تحلیل مقدار RMSE، روش‌های تصحیح اریبی در مقایسه با برونداد مستقیم به‌طور قابل توجهی خطا را کاهش می‌دهند. به‌طوری‌که پس از تصحیح اریبی، مقدار خطای متغیر دمای کمینه برای روش‌های نگاشت چندک تا 42 درصد و برای روش‌های نسبت‌گیری خطی و واریانس به-ترتیب 70.38 و 67.93 درصد کاهش داشته است. مقدار خطای دمای بیشینه نیز پس از تصحیح اریبی به‌ترتیب 59، 65.9 و 67.9 درصد کاهش داشته است. تصحیح اریبی سبب افزایش ضریب توافق (d) تا بیش از دو برابر در متوسط پهنه‌های اقلیمی شده‌است. به‌طور کلی روش‌های تصحیح اریبی بکارگرفته شده در این پژوهش دمای بیشینه را با دقت بالاتری نسبت به دمای کمینه برآورد می‌کنند.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 18
    Publication Date: 2024
    Description: کشور ایران جزو کمربند کوهزایی آلپ - هیمالیاست و به ایالت های لرزه زمین ساختی مختلفی تقسیم شده است. استان کرمان بر اساس طبقه بندی ایالت های لرزه زمین ساختی در زون ایران مرکزی قرار گرفته است. شهر هجدک نیز در ایالت لرزه زمین ساختی ایران مرکزی واقع شده است و رویداد زمین لرزه ای بزرگی را تجربه نموده است. در این تحقیق برای اولین بار شهر هجدک کرمان از نظر شرایط لرزه ای به صورت جامع مورد بررسی قرار گرفته است تا با استفاده از نتایج آن فرایند تصمیم‌گیری برای اقدامات پیشگیرانه به ویژه بهسازی و مقاوم سازی ساختمان ها در برابر زلزله در این شهر تسهیل گردد. در این تحقیق از داده های کاتالوگ زمین لرزه های موسسه ژئوفیزیک دانشگاه تهران و نقشه های زمین شناسی سازمان زمین شناسی استفاده شده است و چشمه‌های لرزه‌ای، پارامترهای لرزه‌ای، جنبش نیرومند زمین محاسبه و تحلیل خطر زلزله به روش احتمالاتی انجام شده است. بر اساس نتایج حاصل از این تحقیق، در فاصله 100 کیلومتری از محدوده شهری 6 زمین لرزه تاریخی، 4141 زمین لرزه دستگاهی با بزرگای بالای 4 از سال 1900 تا اواخر 2023 رخ داده و 8 چشمه لرزه زا از نوع ناحیه‌ای تشخیص داده شده است. ضرایب لرزه خیزی a , b محاسبه شده در این محدوده به ترتیب 86/0 و 88/3 و نرخ لرزه خیزی برای بزرگای 4 و بزرگ‌تر، 47/1 است. بیشترین شتاب سنگ کف در محدوده 45/0 است که این شتاب در محدوده شهر هجدک بین 25/0-35/0 می باشد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 19
    Publication Date: 2024
    Description: در این پژوهش اثر گردش بزرگ مقیاس عرض‌های میانی بر موقعیت ناوه مدیترانه برای بارش‌های فوق‌سنگین طی بازه زمانی 1979 تا 2022 بررسی شد. در این راستا با استفاده از شاخص تموج تغییرات تموج و با تحلیل همدیدی الگوی گردسی جو برای150 بارش فوق سنگین کشور تحلیل شد. نتایج نشان داد که بارش‌های فوق سنگین تحت تاثیر تقویت ناوه اطلس، گسترش جریانات از سمت اروپا و شکل‌گیری ناوه مدیترانه رخ می دهد. شکل‌گیری ناوه اطلس سبب افزایش دامنه امواج، شکل‌گیری پشته برروی اروپا و ناوه مدیترانه می شود. با شکل‌گیری این الگو، ناوه مدیترانه تغییرات طول و عرض جغرافیایی 8 درجه را نسبت به میانگین خود تجربه می‌کند. تغییرات مکانی ناوه مدیترانه به دلیل تغییرات نصف‌النهاری امواج باد غربی برروی اروپا و موقعیت ارتفاع زیاد‌ جنب‌حاره است. متغییرترین قسمت باد غربی منطبق بر بلاکینگ شرق اطلس و ناوه مدیترانه است که با تشدید شیو بین ارتفاع زیاد و کم‌ارتفاع، جریانات نصف النهاری شده و مقدار تموج افزایش‌ می‌یابد. این شرایط منجر به تقویت پشته اروپا، افزایش دامنه امواج، تکوین بندال و گسترش ناوه مدیترانه تا عرض 25 درجه می‌شود. تکوین بلاکینگ اطلس سبب تقویت پشته برروی اروپا و گسترش جریانات به سمت مدیترانه‌ می‌شود. همچنین گسترش‌ نصف‌النهاری ارتفاع زیاد اروپایی منجر به تشدید شیو فشار، شارش‌ جریانات سرد شمالی،‌ تشدید جبهه‌ز‌ایی، تعمیق ناوه مدیترانه تا دریای سرخ می شود. همزمان با تقویت ناوه مدیترانه گسترش‌ شرق‌سوی واچرخند عربستان علاوه بر اینکه منجر به گسترش‌ شرق‌سوی ناوه مدیترانه می‌شود‌، رطوبت مناسبی نیز برای رخداد بارش‌های فوق سنگین کشور تامین می‌کند.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 20
    Publication Date: 2024
    Description: Understanding the stress field is crucial for assessing seismic risks in Northwestern Iran, a region known for its high seismic activity and geological volatility. The intricate tectonic arrangements involving the Arabian, Anatolian, and Eurasian plates contribute to the unstable nature of the area. This study focuses on deducing stress regimes through stress inversion analysis of earthquake focal mechanisms in the North Tabriz Fault system. Analyzing the stress field is essential for understanding the elastic characteristics and geodynamics of the region. The study considers the stress field surrounding the Tabriz Fault, aiming to determine stress parameters and principal stress orientations using focal mechanisms. By analyzing 35 earthquake focal mechanism datasets from the Global Centered Moment Tensor and the Iranian Seismological Center, stress field inversions were conducted using Michael's linear inversion method and the iterative joint inversion method. The two techniques yielded distinct outcomes, with the iterative joint inversion method proving more accurate in determining stress fields and principal stress orientations. The findings indicate the existence of strike-slip faults in proximity to the North Tabriz Fault. The stress direction observed and the trajectory of the fault system suggest the influence of a transpressional mechanism. The predominant right-lateral strike-slip motion observed aligns with the prevailing tectonic regime in the region, providing evidence of strike-slip and thrust faulting stress regimes. The results contribute to a better understanding of the stress field and geodynamic situation in Northwestern Iran. They provide valuable insights for spatial analysis of future earthquakes and assessing seismic hazards in the region.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 21
    Publication Date: 2024
    Description: We, the editors of the Code4Lib Journal, sincerely apologize for the recent incident in which Personally Identifiable Information (PII) was released through the publication of an article in issue 58.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 22
    Publication Date: 2024
    Description: 〈p〉〈em〉The COVID-19 pandemic has underscored the necessity for digital infrastructure and accessibility, particularly in the education sector. This paper investigates the benefits and effectiveness of utilizing Green Cloud Computing (GCC) techniques for the dissemination of educational library data in remote regions of India during this critical period. The GCC model, known for its energy efficiency and reduced environmental impact, is proposed as a robust, scalable, and eco-friendly solution for providing remote educational access. The research utilizes a mixed-methods approach, incorporating both quantitative assessments of data reach and usage, and qualitative surveys to understand user experiences. The study reveals that GCC techniques can significantly improve educational resource distribution, thereby mitigating the educational disparities further exacerbated by the pandemic. These findings reinforce the potential of GCC techniques as a sustainable and inclusive technology in reshaping the educational landscape in remote regions.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 23
    Publication Date: 2024
    Description: 〈p〉〈em〉One of the most crucial global issues of our era is climate change, whose consequences are presently being felt all over the world. As climate change keeps on forgoing, it's important that governments, organizations, and businesses take visionary actions for adapting and protecting themselves from calamities.〈/em〉〈em〉 This paper summarizes the application of Remote Sensing (RS) and 〈/em〉〈em〉Geographic Information System (〈/em〉〈em〉GIS) in observing impact of climate change on drought, soil moisture, land degradation, food security, EHIs’ characterization and blue carbon science and review of AI based climate solutions. The〈/em〉〈em〉 〈/em〉〈em〉integration of advanced machine learning algorithms,〈/em〉〈em〉 〈/em〉〈em〉real-time data analysis, and other cutting-edge technologies could lead to even more effective climate change〈/em〉〈em〉 〈/em〉〈em〉adaptation strategies. AI-activated climate change adaptation strategies have the prospective to significantly〈/em〉〈em〉 〈/em〉〈em〉improve the resilience of infrastructure communities, and businesses to the changing climate.〈/em〉〈strong〉〈/strong〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 24
    Publication Date: 2024
    Description: 〈p〉〈em〉Urban transportation systems face significant challenges due to rapid population growth and development. This study delves into the enhancement of road safety in Navi Mumbai by employing Geographic Information System (GIS) and Remote Sensing (RS) techniques. The escalating rate of vehicular accidents in Navi Mumbai presents a pressing concern. This research investigates accident data and traffic patterns, identifying vulnerable areas prone to accidents and congestion. By conducting spatial analysis using GIS and RS, the study aims to uncover accident hotspots and traffic congestion zones, offering insights into underlying road safety issues. The research methodology involves a multi-stage process. Initial data collection from various sources, including police reports, live traffic data, and satellite imagery, forms the foundation. Geographic coordinates extracted and processed through GIS applications aid in plotting accident locations and creating density maps. Additionally, on-site investigations at strategically chosen locations provide invaluable insights into local conditions, traffic patterns, and contributing factors to congestion and accidents. The findings are presenting tailored solutions for each area, ranging from optimized traffic signal timings to infrastructural improvements. The findings of this study present actionable insights aimed at improving road safety and traffic management in Navi Mumbai. Recommendations encompassing signal optimizations, infrastructure enhancements, and community engagement strategies offer a holistic approach to mitigate traffic congestion and reduce accidents. The collaborative effort with relevant authorities, as highlighted in the study, serves as a crucial step towards implementing these recommendations for meaningful change. This research not only identifies critical areas for intervention but also serves as a model for leveraging GIS and RS techniques to enhance the road safety in urban areas, paving the way for safer and efficient transportation networks in the future.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 25
    Publication Date: 2024
    Description: 〈p〉〈em〉The urgency to transition to renewable energy sources is underscored by the environmental crises stemming from our reliance on non-renewable fuels. This study focuses on assessing wind energy potential in Odisha, India, utilizing satellite data and Geographic Information System (GIS) technologies. The research addresses the critical need for strategic planning and site selection before investing in renewable energy infrastructure. By employing a model that integrates various free satellite datasets and leverages fundamental physical principles, the study calculates wind power density (WPD) at a height of 90 meters above the surface for both onshore and offshore locations. The methodology involves acquiring and processing datasets such as temperature, wind speed, digital elevation model (DEM), pressure, air density, and land use/land cover (LULC) classifications. The model applies equations derived from physical laws to determine key parameters necessary for calculating WPD. Specifically, temperature and pressure data are used to estimate air density, while surface roughness is assigned based on LULC classes with windspeed at 10m to extrapolate wind speed at 90 meters above ground level. The method can be used at any hub height. Results reveal significant wind energy potential in Odisha, particularly along the coastal regions. Jagatsinghpur and Puri emerge as areas with high WPD onshore, while the offshore exclusive economic zone (EEZ) of Odisha exhibits substantial wind energy resources. The model outputs provide valuable insights for various studies related to renewable energy and facilitate informed decision-making in site selection analyses. Furthermore, the study emphasizes the simplicity and effectiveness of the developed model,〈/em〉〈br〉〈em〉making it a practical tool for assessing wind energy potential in other regions as well. Overall, this research contributes to the global effort towards transitioning to sustainable energy sources and combating climate change. By highlighting the renewable energy potential of Odisha, it underscores the importance of harnessing wind energy as a viable pathway towards a cleaner, greener future.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 26
    Publication Date: 2024
    Description: 〈p〉Well logs were utilized to investigate petrophysical properties of the Khurmala Formation’s surface outcrops in Shaqlawa Subdistrict and Tawke Oilfield, e.g., lithology, shale volume, porosity, and fracture. The thickness of the formation is about 15 m in the Shaqlawa section and 42 m in the Tawke Oilfield. Porosity logs were used to estimate porosity; where the porosity values reached a maximum of 52% from the sonic log, 48% from the density log, and 35% from the neutron porosity log. The reservoir quality of the Khurmala Formation, as determined through the analysis of thin sections, which were obtained from outcrop samples, is deemed to be of low quality. The determined shale volume within the examined interval exhibits a moderate level of clay constituents, with the highest gamma-ray measurement indicating a shale content of 29% at some locations within the reservoir. This integrated method using various conventional well logs suggests a great probability of petrophysical properties in the Khurmala Formation to be considered as the reservoir.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 27
    Publication Date: 2024
    Description: 〈p〉The seismic survey is based on the reflected wave’s inherent nature from the interface among layers, which depends on the layer's density and velocity. This is called acoustic impedance and is used to resolve the confusion associated with the stratigraphic structure of the Mishrif formations in the Garraf oil field. The seismic section of the Garraf oil field in Thi-Qar Province, south of Iraq, was analyzed and interpreted. Considering the most important petroleum accumulation reservoir in the Garraf oil field, to update the structural images of the Mishrif Formation. A seismic study of the actual amplitude reflections, temporal maps, and three-dimensional depositional models demonstrated that the Mishrif Formation generate hydrocarbon from an individual structural trap in the presence of oil. Numerous abrupt discontinuities were observed in the seismic reflectors of the reservoir units of the Mishrif Formation, suggesting either a reef or a fault. The correct probability can be shown by establishing a historical match between the reservoir model and the actual behavior of the reservoir or by running a 3D vertical seismic profile log (VSP), which is more precise than the seismic survey previously used to explore faults.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 28
    Publication Date: 2024
    Description: 〈p〉Empirical and statistical methodologies have been established to acquire accurate permeability identification and reservoir characterization, based on the rock type and reservoir performance. The identification of rock facies is usually done by either using core analysis to visually interpret lithofacies or indirectly based on well-log data. The use of well-log data for traditional facies prediction is characterized by uncertainties and can be time-consuming, particularly when working with large datasets. Thus, Machine Learning can be used to predict patterns more efficiently when applied to large data. Taking into account the electrofacies distribution, this work was conducted to predict permeability for the four wells, FH1, FH2, FH3, and FH19 from the Yamama reservoir in the Faihaa Oil Field, southern Iraq.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 29
    Publication Date: 2024
    Description: 〈p〉Rock identification and classification have contributed to the enhancement of drilling oil wells and production reservoir performance. Therefore, understanding the properties of reservoir rocks is a major concern in the petroleum industry. In this context, Young’s modulus and uniaxial compressive strength are major mechanical rock properties essential for defining the engineering classification and modulus ratio of rocks. However, these parameters are used in order to examine the impact of the petrophysical properties on mechanical strength in the Facha member (reservoir) of the Gir Formation in the western central of Sirte Basin, oilfields of central Libya. Dolomite, limestone, dolomitic limestone, and anhydrite are the main lithofacies rock components of this reservoir, as well as of a third member of the Gir Formation (Lower Eocene). Young’s modulus and uniaxial compressive strength were computed from sonic and bulk density well logs data from six wells in four different oil fields. This oil-rich reservoir has an average thickness of 104 m, an average total porosity of 16%, and argillaceous material content (clay) of 4%. According to the engineering classification chart of Deere and Miller, the Facha reservoir rocks have a very low class (E 〈 27.5 Mpa) to high strength class (B ≈ 110-220 Mpa) and have a medium-to-high modulus ratio (M ≈ 200–500 and H ≈ 500). Generally, the diagenesis process, for instance dolomitization, affected both the strength and the modulus ratio.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 30
    Publication Date: 2024
    Description: 〈p〉The Gulneri Formation (Early-Middle Turonian) Deep-water depositional model was constructed using detailed microfacies analysis from the northern Iraqi wells of Kirkuk (K-116) and Bai Hassan (BH-81) as well as the Dokan outcropped area. In the outcropped section, the formation consists of 2 m of thin friable marly limestone with high organic matter and thin-bedded black shale in addition to boulder and gravel-like limestone masses in the lower part. In the K-116 and BH-81 wells, the formation is 4.3 m and 9 m thick, respectively. It is composed mainly of black bituminous, pyritic calcareous shale, and shaley limestone with scattered glauconites. Petrographic studies of seventeen thin sections of the Gulneri rocks reveal that the pelagic/deep marine faunas are the dominant skeletal grain in the micritic groundmass. Three main microfacies were recognized in the studied rocks of the Gulneri Formation, namely lime mudstone, lime wackestone, and lime packstone. However, the latter is absent in the Dokan section. According to their environmental interpretation, these microfacies were grouped into two facies associations (basinal deep water and deep shelf). Based on the results of petrographic and microfacies analyses, it is concluded that the Gulneri Formation was deposited in a basinal deep marine environment with quiet and reducing conditions in the Dokan section and a basinal deep marine environment in the K-116 and BH-81 wells which changed at intervals to a shallower deep shelf setting toward the upper part with semi reducing conditions. The euxinic deep basin that formed at the beginning of the Kurdistan foreland basin's formation was quite anoxic and deeper from the northeast to the relatively shallower basin with semi-reduced conditions towards the southwest. This is how the depositional model of the Gulneri Formation in northern Iraq changed.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 31
    Publication Date: 2024
    Description: 〈p〉Al-Mansuriya gas field is regarded as one of Iraq's most important gas fields because of its good economic gas reserves. The major gas reserves of the Mansuriya field are situated in the Jeribe Formation. The present study aims to determine the petrophysical properties of the Jeribe Formation in the Mansuriya gas field by using the interpretation of different well logs for the open wells MN-1, MN-2, MN-3, and MN-4. The Jeribe Formation was divided into several reservoir units depending on the final results of CPI computer processing interpretation using the Interactive Petrophysics program (Techlog). According to the results of the CPI, the Jeribe Formation in the Mansuriya gas field was divided into seven units, which are J1, J2, J3, J4, J5, J6, and J7. Matrix definition (MID) and density-neutron cross plots indicate that the lithology of the Jeribe Formation consists of a large proportion of dolomite and limestone and a little anhydrite, also in the direction of the gas evident in the Jeribe Formation. The Gamma-ray log showed that the volume of the shale is very small in the Jeribe Formation, and the formation may be clean of shale content. The reason for this small reading is the presence of some radioactive materials in the rocks of formation. Through the readings of the RHOB and NPHI logs and the results of cutoff boundaries, we can conclude that units J1 and J6 represent non-reservoir units and can be considered a cap rock for the reservoir units, and the units J2, J3, J4, and J5 are the main reservoir units for Jeribe Formation according to CPI results and the results of high porosity in these units, as they are characterized by the porosity of up to 24% and water saturation of 40 to 60%, which makes them reservoirs of high quality. The Mn-4 well showed different results from the rest of the wells, and none of its units can be considered a reservoir due to the large water saturation volume.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 32
    Publication Date: 2024
    Description: 〈p〉Small islands have unique characteristics that make them highly vulnerable to environmental damage and disasters. A good understanding of geomorphological characteristics will greatly assist in understanding the potential damage to natural resources that may occur, as well as help in planning better environmental management and assist in more effective disaster mitigation in the future. This study aims to analyze geomorphological characteristics and identify their influence on potential environmental damage and existing geomorphological hazards. The analysis shows that the geomorphological characteristics of Pramuka Cay cause〈br〉it to have potential environmental damage and geomorphological hazards consisting of high vulnerability to sea level rise, water resource scarcity, seawater intrusion, groundwater pollution, coastal erosion and tsunami.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 33
    Publication Date: 2024
    Description: 〈p〉This study aims to calculate the water balance of the Kubaisa Basin in the Western Iraqi Desert using the SWAT model. The study is based on simulating water discharges and the factors affecting them over several years (1990-2023). The geographical, climatic, and hydrological data were collected to run the model. The research results indicate that water distribution in the Kubaisa Basin was estimated during the studied period, including the quantities of surface water, groundwater, and discharges. Climatic results for the Kubaisa Basin indicated an increase in the trend line for total rainfall, temperature, humidity as a relative, and solar radiation, while the trend line retreated for wind speed for the same period. The results of the hydrological components of the basin, which were shown by the SWAT model, namely rainfall (RN-P), surface runoff (SR-Q), flow as lateral (LT-Q), flow as groundwater (GW-F), evapotranspiration as actual (ET), evapotranspiration as potential (PET), water-yield (WLD), and water that permeates past (percolates) the root zone (PEC) which are considered the main elements of the water balance, had values of 79.72mm, 3.10mm, 0.02182mm, 0.0028mm, 76.47mm, 1742.16mm, 3.12mm, and 0.00mm, respectively. This research makes important contributions to the understanding and management of water resources in the Kubaisa Basin and the Western Iraqi Desert regions and can be a basis for future research in the field of improving water sustainability in these regions.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 34
    Publication Date: 2024
    Description: 〈p〉   A regional seismic section was constructed from fourteen local seismic lines from different surveys crossing the central part of Iraq from west to east. The seismic lines’ surveys were performed during the period 1974–1990. The length of the regional seismic section is 662.5 km. The considered seismic lines are unified to the sea level datum. The quality of seismic lines is relatively poor in the western part of the regional seismic section, but it is of good quality in the central and eastern parts. Seven reflectors were identified along the regional seismic section, corresponding to ages from the Ordovician to the Miocene. The formations are Khabour (Mid-Ordovician), Akkas (Upper Silurian), Kurra Chine (Upper Triassic), Najmah (Upper Jurassic), Mauddud (Mid-Cretaceous), Shiranish (Upper Cretaceous) and Fatha (Lower Fars) (Mid-Miocene). The Two-way times for these seismic reflectors from the west to the east are 1691 – 4000 ms, 750-4000 ms, 0-4000 ms, 208-4000 ms, 206 -3310 ms, 205 -2700 ms, and 216-2500 ms for the seven formations; starting from the oldest formation (Khabour Formation to the youngest one (Fath Formation ), respectively. The top depth values of the considered formations were defined from west to east for each formation (0-4.189) km, (0.456-4.880) km, (0.708-5.936) km, (0.802-8.5) km, (0-8.977) km, (0.5-9) km, and (1.8-9) km from the oldest to the youngest formation, respectively. The horizon generally dips towards the east. Two sedimentary basins were identified, the first in the western part of Iraq within the Paleozoic formation, while the eastern basin was within the Cenozoic and Mesozoic formations. These two basins are separated by an uplift at the central part of the regional seismic section. This uplift region was confirmed by gravity and magnetic high anomaly. Many faults were detected along the regional seismic profile. Most of these faults extend from the deeper to the shallower formations. 〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 35
    Publication Date: 2024
    Description: 〈p〉Although the High Folded Zone in the Kurdistan Region of Iraq forms part of the Zagros-Taurus Folds and Thrust belt considered one of the potential hydrocarbon provinces, the oil fields within the zone are still lacking in geophysical exploration and scientific research. So, the rationale behind this study is the prospecting and evaluation of one of the Tertiary carbonate reservoirs at the “WN” oil field in the Duhok area by integrating the 3D seismic and well-log data. The methodology covered seismic interpretation, well logs and their relevant petrophysical analysis, attribute computation, and 3D static property modeling. The constructed reservoir maps revealed a double-plunging rollover anticlinal structure trending in the East-West direction parallel to the Taurus Mountain series. A total of nineteen minor reversal faults trending E-W to ENE-WSW dissecting the northern limb of the anticline were manually interpreted. The isopach map shows various thicknesses ranging from 160 to 330 m, averaging 245 m. The property models show the limited values of their parameters as the effective porosity is limited (0.97-23%), the secondary porosity (0.43-11.7%), permeability (0.00-238.8 mD), the water saturation (12.44-99.8%), and the clay volume (0.00-9.8%). The results of this research indicate that the horizon is a promising reservoir characteristic. 〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 36
    Publication Date: 2024
    Description: 〈p〉The Dammam Formation, a 250-meter-thick geological formation in the Bahr Al-Najaf Depression that is part of the Salman Platform, comprises re-crystallized limestone mixed with nummulite near the base. It was deposited in a shallow marine environment and extends from Al-Qaim to Samawa along the Euphrates River. The formation is part of the secondary Salman Zone of the main outstanding Stable Shelf. The engineering evaluation of the Dammam Formation in Bahr Al-Najaf depression was determined by ten samples which were chosen to represent the study area. The study includes both field and laboratory components. On the field side, data on the study region and samples were obtained. Physical, engineering, chemical, and mineralogy tests were carried out in laboratories. The total density ranges from 1.848 to 2.664 gm/cm〈sup〉3〈/sup〉, the porosity value ranges from 5–20 %, while the water absorption of limestone rocks values 1-7.7 %. Engineering tests were performed, including uniaxial compressive strength, which ranges between 59 and 177 Mpa. The rocks of the Dammam Formation are suitable for the manufacture of Portland cement according to global standards, as supported by chemical analysis.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 37
    Publication Date: 2024
    Description: 〈p〉The provenance and tectonic setting of clastic sediments present in the Miocene Red Bed Series located in northeastern Iraq were analyzed. The analysis is based on the composition of detrital chrome spinel and represents the first examination of this topic. The detrital chrome spinel exhibits Cr # (Cr/(Cr + Al)) values ranging from 0.54 to 0.77 and Mg # (Mg/(Mg + Fe〈sup〉2+〈/sup〉)) values ranging from 0.37 to 0.69. This indicates a potential incorporation of ultramafic sources, possibly including peridotites (namely Harzburgite and Lherzolite precursors), within the supra-subduction zone. The analysis of modified Cr-spinels extracted from the Red Beds indicates that the source rocks underwent a process of metamorphism and that the Cr-spinel particles were surrounded by a magnetite rim. The Cr-spinel compositions of the examined samples are situated tectonically in the fore-arc setting of peridotite protoliths, except for a small number of samples that exhibit boninite affinity. The observed resemblance in the Cr-spinel number content between the examined specimens and the Zagros Ophiolite peridotites suggests that the Red Beds may have originated from the Cretaceous Mawat Ophiolite Complex. The deposition of Paleocene Walash-Naopurdan rocks indicates that the lower allochthon served as a source during this process. The tectonic context of the Red Bed Series suggests that the allochthonous terranes in the Mawat region were transported and obducted onto the northeastern Arabian passive margin in the early Miocene period. The deposition of the Red Bed Series occurred concurrently with the closure of the Neo-Tethys Ocean in the Miocene.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 38
    Publication Date: 2024
    Description: 〈p〉Indirect geophysical methods are increasingly associated with direct underground methods in〈br〉investigating the subsurface to address environmental and geotechnical problems and reduce〈br〉the cost of underground studies. These methods make it possible to explore large areas with〈br〉acceptable precision, time, and cost. The present study combines the electrical resistivity〈br〉method with the California Bearing Ratio for exploring an area located west of the〈br〉Nouakchott port in Mauritania. The study aims firstly to verify that the thickness of the〈br〉backfill layer must be less than 2 m throughout the entire study area and secondly to map〈br〉areas with low California Bearing Ratio values (〈80%) indicating substandard backfill〈br〉compaction using 2D Electrical Resistivity Tomography imaging survey and regression. The〈br〉measured Electrical Resistivity values exhibit a good nonlinear regression with California〈br〉Bearing Ratio, following Archie's equation. A map of California Bearing Ratio variation was〈br〉derived from the Electrical Resistivity values, indicating the distribution and variation of soil〈br〉strength in the study area. The results revealed that the backfill layer did not meet the〈br〉standards, with approximately 35% of the total area having a California Bearing Ratio value〈br〉below 80%. The areas with poor compaction requiring treatment were primarily located in〈br〉the southern sector, followed by the middle and eastern sectors.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 39
    Publication Date: 2024
    Description: 〈p〉This study focuses on the Yamama Formation, a significant carbonate reservoir in southern Iraq that is one of the most important productive reservoirs in the region. The Formation is characterized by porous limestone interspersed with thin layers of argillaceous and tight limestone. The Yamama reservoir in the Faihaa oil field is divided mainly into four units; YA, YB, YC, and YD. YA and YB units are considered to be the most important oil-bearing subunits due to their good petrophysical properties. The main objective of the study is to determine the optimum production rates of four naturally flowing wells in the Faihaa oil field using the Inflow Performance Relationship and Vertical Lifting Performance curves. The study investigates four critical parameters; tubing size, water cut, reservoir pressure, and wellhead pressure, and their impact on well performance. The study finds that wellhead pressure is the primary determinant of well performance, and deviations from the original tubing size have adverse effects on well performance. An increase in water cut beyond the recommended threshold, coupled with a reduction in reservoir pressure, results in decreasing well performance. The study underscores the importance of careful monitoring and analysis of these parameters to sustain and enhance well performance in the Faihaa oil field, providing valuable insights for well operators and petroleum engineers. The study's findings can be used to optimize well performance and increase oil production rates, with significant implications for the petroleum industry.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 40
    Publication Date: 2024
    Description: 〈p〉Among the most important formations to be deposited during the Tertiary period was the Jeribe Formation. It has been investigated in two wells (Mn-1 and Mn-2) in the eastern Iraqi Dyala Government's Mansuria Oil Field. To identify fauna, 65 thin sections are examined under a microscope. Benthonic Foraminifera and limestone, occasionally dolomitized, make up its composition. There are twenty species of coralline and foraminiferan algae known to science. There were two unique biozones in the range. These biozones are the Ammonia beccria Linne Range Zone (Middle Miocene) and the Borelis melo curdica (Reichel) Range Zone (Early Miocene). The age of the formation was estimated to be Early Middle-Miocene based on these biozones of Foraminifera and other fossils such as gastropods, pelecypods, coral, fossils, Brayozoa, shell fragments, Echinoderm, echinoid plate, and echinoid spine.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 41
    Publication Date: 2024
    Description: 〈p〉Friction angle (φ) and Cohesion (C) are the most important factors to depict rock's shear strength. The friction angle (φ) expresses a unit of rock's capacity to endure shear stress. For the optimization of drilling operations, monitoring of the reservoir, and production of hydrocarbons, the prediction of friction angle is essential. From laboratory measurements or wireline logging data, this parameter can be empirically predicted. The main goal of this study is to develop a new correlation for predicting friction angle for carbonate formations from well logs using the typically accessible well log data (i.e. neutron porosity, gamma ray, bulk density, and sonic logs) and core data. A total of 5197 well log data points were collected from carbonate formation with depth interval of (1920 m to 2711 m) from Rumaila oil field. For all 5197 data points neutron porosity, and gamma ray logs were recorded as a function of depth, and the corresponding shale volume and total porosity were estimated. In addition to these well log data, 20 data core points with 9 different values of friction angle were collected.〈br〉The developed correlation's estimated friction angle has been contrasted with measured ones. The results show that the new correlation is able to predict the friction angle of carbonate rocks with high accuracy (i.e. R coefficient of the new correlation was 90% and average absolute error of 1.6%).Thus, we conclude that the new correltion can be used to estimate the friction angle for carbonate formation. The new correlation helps in providing continues profile for friction angle with depth and leads to reduce the cost of estimating the rock〈br〉strength.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 42
    Publication Date: 2024
    Description: 〈p〉In brownfield sites, two proposed shallow horizontal targets were numerically modelled to mimic variable underground conditions; these targets were sequenced vertically in a different manner. Synthetic 2D electrical resistivity datasets were generated using the RES2DMOD and then inverted by using RES2DINVx64. These targets have different lengths, one with a higher and the second with a lower resistivity value relative to the background resistivity. The effectiveness of dipole-dipole, Wenner, and Wenner-Schlumberger configurations was tested by conducting a qualitative comparison. The inverted resistivity images suggest that the target sequence has a significant effect on the configuration detectability. The high resistivity target was conveniently recognized when it overlies a low resistivity target. Dipole-dipole configuration showed optimum results in recognizing complicated underground conditions.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 43
    Publication Date: 2024
    Description: 〈p〉Permeability derived from magnetic resonance advanced logging tools was used to unlock the Pliocene sandstone reservoir heterogeneity. Permeability prediction from well logs is a significant target due to the unavailability of core data. The hydraulic flow unit approach is used to classify the reservoir rocks according to their porosity-permeability relationship. The predicted permeability is calculated using Sapphire-Dh magnetic resonance porosity and permeability relationship for each flow unit. Flow Zone Indicator and the quality flow〈br〉unit have a direct proportion relationship. For the model's verification, the predicted permeability is plotted against the measured resonance permeability in Sapphire-Dh as a reference studied well, showing highly matching results. Accordingly, the applied approach is implemented in the other three wells, which have neither core samples nor advanced logs measurements.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 44
    Publication Date: 2024
    Description: 〈p〉Constructing roads in geologically unstable regions such as northern Morocco poses a major challenge. The Tizi Ouadrene sector, located in the Rif External Nappe of the Rif Belt, exemplifies a significant complexity in this issue, with a risk of landslides threatening the road embankments in this area. This study aims to characterize the frequent Cretaceous shales in the study area and analyze the landslides that have occurred on the road embankments cut into these shales. It examines the role of lithology, geometry, tectonics, human activity, and water in these landslides. The geological structure of slopes and their geometric configuration are crucial factors in determining the occurrence, distribution, and other characteristics of these landslides. Defects are controlled by the relative position of sedimentary and tectonic discontinuities, as well as the relative abundance of indurated shales compared to crushed ones. Crushed shales are susceptible to rotational slides, while the indurated ones are prone to planar and wedge sliding. The latter are mainly associated with bedding planes, particularly those oriented N65-80 with slopes facing south and SSE, as well as NW-SE and NE-SW-trending fractures. Hydrological, tectonic, and anthropogenic factors also contribute to the instability.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 45
    Publication Date: 2024
    Description: 〈p〉This study deals with the petrography and heavy mineral analysis of the Injana sandstone at Al-Habbaniyah City. Thirteen samples are collected from the Injana Formation. A petrographic study is achieved on ten samples while all samples are analyzed for heavy minerals. The petrographic analysis showed that the common components of the Injana sandstone are rock fragments, especially sedimentary fragments. Quartz grains (monocrystalline and polycrystalline) and feldspars (k-feldspar and plagioclase), bounded by matrix and carbonate cement. The suggested provenance for the Injana Formation is mainly sedimentary and igneous sources and the less dominant metamorphic source. These sandstones are considered to be mineralogically submature-immature and classified as litharenites. Heavy minerals analysis showed two sets of minerals including opaque and transparent minerals, the opaque minerals are significant components of the heavy mineral assemblages, then chlorite, epidotes, amphiboles, garnet, pyroxenes (ortho and clino), zircon, tourmaline, biotite, muscovite, rutile, and others. This assemblage implies that the dense minerals are typically found in basic igneous and metamorphic rocks, with less frequent occurrences in acidic igneous and reworked sediments. According to QLF and QmFLt classifications, the tectonic provenance of the Injana sandstone is described as recycled orogen. The MF-MT-GM classification showed that the sandstone of Injana is derived primarily from active continental margins. The result of maturity MI and ZTR revealed low values of maturity, the MI value ranges between 0.6 to 1.5 with an average of 0.9 and ZTR Maturity ranges between 0.7% and 9% with an average of 3.9%, these low values of maturity indicate sub-mature to immature sandstone.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 46
    Publication Date: 2024
    Description: 〈p〉This study included conducting a geometric analysis of the reservoir of the proposed Al-Baghdadi Dam in the downstream area of the Haditha City northwestern part of Anbar Governorate. The digital elevation model with an accuracy of 10 × 10 m per pixel area used to extract the geometric elements by the ArcGIS, Global Mapper, and Surfer software, which are included: negative volume (storage volume), positive volume (size of islands), negative surface area (uneven area of the bottom of the reservoir), and area Positive surface (uneven area of islands), negative flat area (water surface area), positive flat area (area of the projection of islands), average depth of reservoir, and average thickness of islands at each hypothetical level from 77.5 to 106 ms and with a contour interval of 0.5 m above sea level. The relationship between the geometric elements and the water level was used to clarify the extent of variation of the values of these elements with the water level fluctuation, and to delineate the area that will be subjected to immersion in the event of the construction of the dam and to determine the optimal and safest operating level. In contrast, it produces less submerged areas and less contact with the rock exposures of the formation in the study area.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 47
    Publication Date: 2024
    Description: 〈p〉The study area is located in the southern desert of Iraq, near the Al-Salman Depression, about 130 km southwest of Al-Samawa City. The Collection of data of this study depends mainly upon field surveys, sample collection of rocks, soil, plants, and animals besides interviews with locals as well as photographing of interesting aspects. The geodiversity of the study area comprises geological features, geomorphological features, soil types, and water resources. The exposed rocks of study area are composed mainly of carbonate rocks, in addition to marl, sandstone, and claystone, which belong to the Middle member of the Dammam Formation (L. Eocene). The main landforms found near the Al-Salman area are flat terrain, depressions (faidhats), wadis, caves, and sinkholes. Three types of soils were recognized; silty clay, clayey silt, and sandy soils. The main water resources are the ephemeral streams (wadis), and water wells in sinkhole, besides the mechanical and hand-dug wells. Geodiversity features formed many habitats in the study area such as Wadi Al-Owja, depressions (faidhats), flat terrain, and sinkhole. The present study reveals that biodiversity includes a wide diversity of plants, invertebrates, and vertebrates. Some species were restricted to certain habitat types in the study area, while other species proved to be more generalist.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 48
    Publication Date: 2024
    Description: 〈p〉One key step when interpreting seismic reflection data is sequence stratigraphy, which has improved with well logs and seismic data. By analyzing the different layers of sediment and rock, we can better understand the geologic history of an area and make more accurate predictions for hydrocarbon exploration. The current research focuses on interpreting seismic lines from the 2D seismic surveys conducted in the Al-Fao area and data from wells in the Siba gas field to construct a stratigraphic model within the Yamama Formation, to identify hydrocarbon traps and determine the most promising zones for hydrocarbon exploration. Yamama Formation is divided into two main units representing transgressive and regressive facies deposited in highstand system tract. Six seismic facies were identified (wavy, mound shape, oblique parallel, sigmoid, chaotic, and parallel), which reflected the deposition of Yamama Formation in a ramp setting with a gentle slope. Instantaneous phase attribute was utilized, which focused on the lateral changes of seismic facies and provided detailed information about the architecture of Yamama Formation depositional basin. The results of the seismic attributes analysis included identifying carbonate buildups and progradation stacking patterns with the presence of direct hydrocarbon indicator. Three main seismic stratigraphic indexes representing potential stratigraphic traps have been identified. These three stratigraphic features reflect the facies of shoal carbonate sediments in the last depositional cycle of Yamama Formation (Highstand). The stratigraphic model showed the best image of the depositional environment of Yamama Formation that corresponds with the seismic data interpretation and identifies the promising hydrocarbon traps.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 49
    Publication Date: 2024
    Description: 〈p〉In this study, the stable isotop 〈sup〉18〈/sup〉O and 〈sup〉2〈/sup〉H has been used to investigate the interaction of surface water (SW), and groundwater (GW) in Al-Taji district/ Northern Baghdad for two seasons (March and August 2022). 16 Samples were collected from water resources in the Al-Taji district (Tigris channel, Tigris River, and groundwater), in each season water samples from 8 Tigris channel, 5 drilled wells, and 3 Tigris River were taken for the analysis of the isotopes 〈sup〉18〈/sup〉O and 〈sup〉2〈/sup〉H. The average analysis results of 〈sup〉18〈/sup〉O and 〈sup〉2〈/sup〉H in the Tigris channel, Tigris River, and groundwater were found to be -3.435‰ and -18.6094‰, -2.07167‰ and -17.81‰, -4.125‰ and -34.707‰ respectively. The results, generally, show a comparable range of isotope content on the Tigris Channel and groundwater (W1 about 1 km from the Tigris Channel). This indicates a mixing/interconnection between groundwater and the Tigris River, and it could be concluded that the wells (W1 and Ch1 and Ch2) near the Tigris channel have been recharged or mixed from them. 〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 50
    Publication Date: 2024
    Description: 〈p〉The study is situated in the Kokoe Region of Central Buton Regency, Southeast Sulawesi,〈br〉specifically in the southern part of Kabaena Island. Its primary objective is to assess the〈br〉potential of nickel laterite in the designated area. The research methodology involved〈br〉microscopic analysis of bedrock using a polarizing microscope, examining the drilling data,〈br〉including logging descriptions, and the utilising of XRF geochemical analysis (Ni, Fe,〈br〉Al2O3, Co, Mg, and SiO2) from 32 drilling sites. Both elementary grade and laterite profiles〈br〉were visualized using Strater 5 software to simplify the representation of laterite profiles.〈br〉Petrographic analysis divided the bedrock into two lithological units: serpentinized〈br〉lherzolite and serpentinite. The laterite profiles in the study area were classified into four〈br〉types: type A, type B, type C, and type D. Type A profiles consist of bedrock, saprolite, and〈br〉limonite layers, covered by clay and colluvium. Type B profiles lack limonite and instead〈br〉exhibit saprolitic rock and rocky saprolite layers on top of the bedrock. Type C profiles〈br〉comprise bedrock, saprolitic rock, rocky saprolite, limonite, and topsoil layers. Type D〈br〉profiles contain three zones, namely bedrock, colluvium, and clay, but lack limonite and〈br〉saprolite layers. Among the four profile types, type A and type C profiles show promising〈br〉potential due to higher average grades of Ni and thicker saprolite zones compared to the〈br〉type B and the type D profiles.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 51
    Publication Date: 2024
    Description: 〈p〉The current research aims to evaluate the hydrogeological characteristics of the water-bearing layers in the study area. Because of the absence of observation wells near the pumping wells, the single pumping test experiment was achieved at seven wells GW1, GW2, GW8, GW9, GW11, GW13, and GW16 distributed in the study area. The pumping test records were analyzed by using Aquifer Test 2016.1 software, which is based on four methods namely, Theis, Hantush, Cooper-Jacob, and Theis recovery. The average values of transmissivity for the upper aquifer in the study area ranged between 13.4 m〈sup〉2〈/sup〉/ day and 279 m〈sup〉2〈/sup〉/ day, while the hydraulic conductivity ranged between 0.162 m/day and 4.14 m/day, and the storativity is 0.166 and 0.826. For the lower aquifer the transmissivity is ranged between 11.4 m〈sup〉2〈/sup〉/ day and 177 m〈sup〉2〈/sup〉/ day, the hydraulic conductivity is 0.214 m/ day and 1.17 m/ day, and the storativity is 0.0791 and 0.99.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 52
    Publication Date: 2024
    Description: 〈p〉One of the oil field's main reservoirs is the Mishrif Formation, which is found in the Nasiriyah oilfield in the southern part of Iraq (Late Cenomanian-Early Turonian). It was one of the three oil wells selected for this study. To extract various petrophysical parameters for open wells indicated by gamma ray, density, neutron, self-potential, acoustic, and resistance, a variety of well logs were analyzed. The qualitative interpretation of the logs allowed for the identification of different types of rocks, the boundaries and thicknesses of the strata, the depths of the formation, and the zones that contained water and hydrocarbons. The quantitative interpretation, which assesses the reservoir's attributes by computing its porosity, the quantity and distribution of the shales, the levels of water and oil saturation, and other elements, that are necessary to evaluate the reservoir’s units in the research wells. The features of the study wells and the used logs were reported, to make clear how these features were distributed among the sample wells. The collected petrophysical characteristics were handled and shown as charts. There are two types of units within the Mishrif Formation: reservoir-containing CR-I, MA, CR-II, and MB. In most wells, reservoir units are made up of hard, low-porous rocks that are positioned between highly porous reservoir units. For a few wells, the MA unit had low residual and mobile hydrocarbon percentages, whereas the MB unit had large percentages, while the hard rocks had significant percentages of water saturation.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 53
    Publication Date: 2024
    Description: 〈p〉Soil erosion and sediment transport by runoff are among the largest environmental problems threatening agricultural lands in the world. Their often irreversible degradation is a major source of socio-economic imbalance in vulnerable areas. The management and control of soil loss in these areas are essentially based on erosion rate modeling generally using two methods: Revised Universal Soil Loss Equation and Modified Universal Soil Loss Equation. The Modified Universal Soil Loss Equation method results often present outliers' values compared to the Revised Universal Soil Loss Equation method. This paper aims to predict and control the MUSLE method values in watersheds based on a database of Revised Universal Soil Loss Equation method values in more than 70 watersheds around the world. For this purpose, Geo-statistical analysis (Simple Linear Regression method) was used to allow the development of a model with a coefficient of determination R〈sup〉2〈/sup〉= 0.96 (validity of 96%) and thus the estimation of the tolerable uncertainties of the Modified Universal Soil Loss Equation method by the equation: Y (V_ Modified Universal Soil Loss Equation LE) = 0.76 X (V_RUSLE) + 1.7.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 54
    Publication Date: 2024
    Description: 〈p〉This research focuses on the study of the physical and chemical properties of red clay found〈br〉in the Injana and Fatha Formations. The aim is to establish correlations among various〈br〉physical and chemical elements using geographic information system (GIS), remote sensing,〈br〉and a regression analysis model. Laboratory analysis, including X-ray diffraction, was〈br〉conducted to determine the properties of the clay, as well as nonclay minerals. Statistical〈br〉Package for the Social Sciences software was utilized for regression analysis to determine〈br〉property correlations. Landsat 7 and Landsat 8 images were employed to establish〈br〉relationships between digital numbers and soil properties. The study revealed that the dry〈br〉density of the Fatha Formation was lower than that of the Injana Formation. Silt content was〈br〉highest among all samples, ranging from 28% to 93%. The Fatha Formation exhibited a high〈br〉gypsum rate due to the presence of gypsum layers. Strong positive correlations were observed〈br〉between gypsum and sulfate, as well as between electrical conductivity and total soluble salt.〈br〉Multiple linear regression analysis was appropriate for clay properties, with regression〈br〉coefficients ranging from 0.6 to 0.72. Nonlinear regression yielded better results than linear〈br〉regression, with high regression coefficients. Landsat images proved valuable for obtaining〈br〉data in remote or expansive areas. The association between clay characteristics and Landsat〈br〉8 provided superior results compared to Landsat 7.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 55
    Publication Date: 2024
    Description: 〈p〉This is the first time that radiological assessment achieved in the Baghdad International Airport (BIA) in Iraq. Twenty-three sites were sampled from upper 5 cm of the surface soil within the BIA to be analyzed for the radioactivity of natural radionuclides Ra-226, Th-232 and K-40 and the artificial radionuclide, Cs-137 using gamma spectroscopy based on Hyper pure Germanium detector (HPGe). Ten samples out of the 23 samples were analyzed for U-238, U-235 using the Neutron Activation Analysis method. To determine the percentage of DU [DU (%)] which is calculated from the 〈sup〉235〈/sup〉U/〈sup〉238〈/sup〉U isotope ratio. The study showed that there is a possibility of slight contamination with depleted uranium in two sites out of the 23 sites that were examined. The average activities of Ra-226, Th-232, and K-40 in the study area are within the limits of world averages, while there are evidences that new feeding of Cs-137 in the region, reaches about 19 Bq/kg, from the new global fallout after Chernobyl accident. The measured and calculated absorbed doses in the study area were within international limits and no need for farther monitoring. Annual effective dose equivalent due to resuspension of Ra-226 is estimated to be 1.0E-10Sv, and this value is negligible compared with 1 mSv permissible value for public recommended by ICRP.〈/p〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 56
    Publication Date: 2023
    Description: This Article explores the question of what, if any, of the copyrights to tokenized works should be transferred or licensed to NFT purchasers, and clarifies issues of copyright transfer and licensing in the world of NFTs and blockchains.〈div class="enclosure"〉〈/div〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 57
    Publication Date: 2023
    Description: By dispelling blockchain misconceptions, highlighting the code in certain NFT smart contracts on the Ethereum blockchain, and probing the concept of ownership through the lens of IP law, we can demystify what NFT “ownership” really means for both creators and NFT holders.〈div class="enclosure"〉〈/div〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 58
    Publication Date: 2023
    Description: ESG in general and an agenda focused on sustainability in particular can and should be applied to taxation to ameliorate the impact of the crypto industry on society and the planet.〈div class="enclosure"〉〈/div〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 59
    Publication Date: 2023
    Description: The Author proposes an effect-based jurisdiction rule limited by a de minimis exception to mitigate blockchain’s impact on conduct-based jurisdiction rules, enhance legal certainty, and promote international coordination.〈div class="enclosure"〉〈/div〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 60
    Publication Date: 2023
    Description: Blockchain games and their characteristics open new conversations on novel ways of addressing the wealth gap and income inequality, exploring property ownership possibilities, and encouraging the blurring of work and play culture.〈div class="enclosure"〉〈/div〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 61
    Publication Date: 2023
    Description: زمین لغزش ها به عنوان حوادث طبیعی رایج، در بسیاری موارد منجر به زیان های اقتصادی قابل توجه و حتی تلفات جانی می شود. بنابراین بررسی زمین لغزش ها به منظور کاهش خسارات ناشی در مطالعات اولیه پروژه های عمرانی مخصوصا سازه های خطی در مناطق دارای پتانسیل زمین لغزش از اهمیت بسزایی برخوردار است. به همین منظور پس از وقوع زمین لغزش در مناطق لنگار و تلمادره که موجب تخریب قسمتهایی از جاده کیاسر- سمنان در استان مازندارن شد، تحقیقات توموگرافی الکتریکی دوبعدی برای تشخیص سطح لغزش و توده ناپایدار در محل زمین لغزش ها صورت گرفت تا در ساخت جاده جدید ملاحضات لازم در نظر گرفته شود و از بروز خسارات بیشتر جلوگیری به عمل آید. در این تحقیق ابتدا داده های مقاومت ویژه الکتریکی در 6 پروفایل با آرایه های دوقطبی-دوقطبی، قطبی-قطبی و سونداژ مقاومت ویژه الکتریکی با آرایه شلومبرژه برداشت گردید. در مرحله دوم داده های صحرایی با استفاده از نرم افزارهای Res2dinv و IPI2win وارون و سپس نتایج مورد تفسیر قرار گرفتند. نتایج حاصل از توموگرافی مقاومت الکتریکی (ERT) در زمین لغزش لنگار با توجه به خروجی مدلهای مقاومت ویژه الکتریکی و زمینشناسی منطقه، وجود 4 لایه اصلی در مقطع ها را نشان میدهد. همچنین مطالعه نشان داد در زمین لغزش تلمادره سطح جدایش بین توده رس و شن و ماسه اشباع با سنگ بستر سطح گسیختگی زمین لغزش میباشد. مدل وارون مقاومت ویژه حاصل از داده های سونداژ الکتریکی در نرم افزار IPI2win فقط جهت مقایسه و نمایش یک مدل کلی ارائه شده است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 62
    Publication Date: 2023
    Description: The behavior of ion acoustic wave (IAW) is studied in an electron-ion plasma consisting of cold ions and nonextensive electrons. In this study, the reductive perturbation method is used and the new point is the non-uniformity of the nonextensive parameter in the media. We want to achieve more realistic results of ion acoustic wave behavior by better using the reductive method. In fact, the variation in the behavior of ion acoustic wave when it encounters the nonextensity perturbation region is examined. Perturbation area is a part of plasma where the nonextensivity changes slightly. Therefore, the presence of nonextensivity is introduced as the first order perturbation and the phase velocity is applied as a fixed parameter in the calculations. The modified KdV (mKdV) equation is derived to describe the behavior of the ion acoustic wave propagation in this model. The obtained equation clarifies the change of the soliton profile when moving in all through the perturbation area. Our numerical results show that part of ion acoustic waves propagates as oscillatory shock wave in the perturbed area. The results of this investigation can be helpful for understanding the behavior of ion acoustic waves in an astrophysical environment and space plasmas with varying nonextensivity (Qiu et al., 2020; Silva et al., 1998; Lima et al., 2000).
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 63
    Publication Date: 2023
    Description: در این پژوهش از مدل فرابنفش قابل مشاهده وردسپهری Tropospheric Ultraviolet-Visible (TUV) برای پیش‌بینی شاخص پرتو فرابنفش استفاده شد. این مدل برای پیش بینی Ozone Monitoring Instrument(OMI) به داده‌های ازن، سپیدایی و عمق نوری ذرات معلق نیاز دارد. برای مقادیر ستون ازن و سپیدایی از داده‌های ازن سامانه پیش‌بینی جهانی Global Forecast System (GFS) و (AOD) Aerosol Optical Depthاز داده‌های مدل Whole Atmosphere Community Climate Model (WACCM) استفاده شد. 612 مورد مطالعاتی در کل سال 2020 از هر یک از 12 ماه سال از نقاط مختلف کشور انتخاب شد. داده‌های GFS، WACCM و OMI برای تاریخ‌های ذکر شده استخراج و در نقاط مورد نظر درونیابی شدند. سپس مقادیر درونیابی شده به همراه طول، عرض و ارتفاع نقاط به عنوان ورودی به مدل TUV داده شدند و مقدار Ultraviolet Index (UVI) پیش‌بینی شد. به دلیل عدم دسترسی به مقدار واقعی UVI در کشور، داده OMI به عنوان داده مشاهداتی برای مقایسه با مقادیر پیش‌بینی مورد استفاده قرار گرفت. از سنجه‌های متداول آماری(Mean Error (ME), Mean Absolute Error (MAE), Root Mean Squared Error (RMSE)) و ضریب همبستگی پیرسون برای درستی‌سنجی مقدار پیش‌بینی با داده مشاهداتی استفاده شد. همچنین مقدار خطا با مقدار عمق نوری ذرات رابطه دارد؛ هر چه عمق نوری ذرات معلق بیشتر باشد، خطا نیز بیشتر است. نمودار ضریب همبستگی نیز نشان داد که بین مقادیر پیش‌بینی و مشاهده همبستگی بالایی وجود دارد. این تحقیق اولین پژوهش در زمینه پیش‌بینی شاخص پرتو فرابنفش در کشور می‌باشد که نتایج رضایت بخشی به همراه داشته است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 64
    Publication Date: 2023
    Description: در این مقاله جریان پوسته به صورت نرخ لغزش افرازی روی گسلها در شمال باختر فلات ایران با استفاده از مشاهدات GPS و مدل اجزای مرزی برآورد میشود. برای افراز نرخ لغزش نخست گسلها به صورت ساده صفحات مستقیم، سپس به صورت صفحات مستقیم شبکه بندی شده و در نهایت به صورت شبکه بندی با هندسه واقعی برای مدلسازی درنظر گرفته میشوند. شرط مرزی تنش با استفاده از مشاهدات GPS به روش کمترین مربعات محاسبه شده و به مرکز سلولها اعمال میشود. این مدل به مجموعه داده های اثر سطحی به روز شده گسلهای شمال باختر ایران – خاور ترکیه برازش میشود. در این تحقیق با مدلسازی نشان داده میشود که بیشینه حرکت امتدادلغز راست‌گرد در شمال باختری ایران در گسل شمال تبریز رخ میدهد. به منظور صحت سنجی مدل، برآورد نرخ لغزش افرازی با نرخ‌های لغزش حاصل از مطالعات ژئودتیکی و دیرینه‌لرزه شناسی در گسل شمال تبریز که در فرآیند مدلسازی مورد استفاده قرار نگرفته، مقایسه شده ‌ست. برآورد نرخ لغزش با روشهای زمین شناسی در امتداد گسل شمال تبریز کمتر از نرخ لغزشهای امروزین برگرفته از مشاهدات GPS است. در این تحقیق نشان داده میشود که افراز نرخ لغزش حاصل از مشاهدات GPS با درنظر گرفتن اندرکنش مکانیکی این اختلاف را حل میکند. نرخ‌های لغزش افرازی برآورد شده همگی کمتر از محدوده نرخ‌های لغزش ژئودتیکی مبتنی بر GPS یا رادار بوده و با نرخ‌های لغزش زمین‌شناسی سازگارترند. در نهایت مدلی به دست آمده است که بهترین انطباق را با قیود زمین شناسی دارد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 65
    Publication Date: 2023
    Description: از آنجا که کشور ایران در منطقه‌ای خشک و نیمه‌خشک واقع شده است، همواره در معرض کمبود بارش، دما و تبخیر بالا و در نتیجه خشکسالی‌های متعدد با اثرات مخرب بوده است. لذا پایش، مدل‌سازی و پیش‌بینی این پدیده به ویژه در مقیاس ماهانه می‌تواند نقش بسزایی در مدیریت ریسک خشکسالی داشته باشد. هدف مطالعه حاضر، توسعه مدلی با قابلیت محاسبه شاخص‌های SPI و SPEI در پیش‌دید یک‌ماهه با بهره‌گیری از برونداد بارش و دمای مدل CFS.v2 که توسط مدل منطقه‌ای RegCM4 ریز مقیاس شده است، می‌باشد. ابتدا با استفاده از داده‌های دمای ریز مقیاس شده مدل CFS.v2 در دوره 2010-1982 و همچنین داده‌های ERA5، مقادیر تبخیر-تعرق پتانسیل ماهانه به روش هارگریوز-سامانی محاسبه گردید. سپس داده‌های ریز مقیاس شده بارش و تبخیر-تعرق پتانسیل سامانه CFS.v2-RegCM توسط مدل‌های درخت تصمیم و ماشین بردار پشتیبان پس‌پردازش گردیدند. داده‌های ریز مقیاس شده به عنوان ورودی و داده‌های بازتحلیل ERA5 به عنوان داده‌های مرجع جهت آموزش (2002-1982) و آزمون (2010-2003) استفاده شدند. در پایان، از داده‌های ریز مقیاس شده و پس‌پردازش شده جهت محاسبه مقادیر SPI و SPEI یک ماهه مدل و از داده‌های ERA5 برای محاسبه مقادیر نظیر مرجع استفاده گردید. مقایسه داده‌های پس پردازش شده بارش و تبخیر-تعرق پتانسیل با داده‌های نظیر بازتحلیلERA5 نشان داد که مدل درخت تصمیم از کارایی بالاتری نسبت به مدل ماشین بردار پشتیبان برخوردار است. همچنین مقادیر SPI و SPEI محاسبه شده با داده‌های منتج از سامانه CFS.v2-RegCM4 که با مدل درخت تصمیم پس‌پردازش شده‌اند با مقادیر نظیر منتج از داده‌های بازتحیلی ERA5 همخوانی قابل قبولی داشتند.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 66
    Publication Date: 2023
    Description: این پژوهش ارائه دهنده برآوردی جدید برای فرونشست شمال شرق ایران از طریق آنالیز سری‌های زمانی 31 ایستگاه شبکه خراسان به‌عنوان بخشی از شبکه ایستگاه‌های دائمی ژئودینامیک و GNSS ایران (IPGN) واقع در شمال شرق ایران از ابتدای سال 2006 تا پایان سال 2016 است. برآورد یاد شده، حاصل از بردار سرعت ایستگاه‌های شبکه در چارچوب ITRF2014 بر مبنای آنالیز سری زمانی در دو بخش مدل تابعی و مدل تصادفی است. آنالیز مدل تابعی طی مراحل کشف پرش‌ها، تعیین مدل حرکت، کشف اشتباهات و آزمون آماری در قالب یک فرآیند تکرار انجام شده است. در آنالیز مدل تصادفی، همبستگی مکانی به روش پشته‌سازی وزن‌دار و همبستگی زمانی به روش برآورد ماکزیمم درستنمایی (MLE) و درنظر گرفتن مدل نویزی ترکیب نویز سفید و نویز فلیکر بررسی می‌شود. نتایج تحقیق نشان می‌دهد که: (1) هر یک از ایستگاه‌های این شبکه در بازه زمانی 11 ساله بطور متوسط دارای 9 پرش غیر لرزه‌ای بوده‌اند. (2) فیلترینگ مکانی، میانگین نرم بردار باقیمانده‌های مولفه‌های شرقی، شمالی و قائم را بترتیب 17/30، 40/29 و 90/17 درصد کاهش می‌دهد. (3) پنج ایستگاه GOLM، GRGN، NFRD، NISH و SHRN دارای فرونشست غیرطبیعی بوده و سه ایستگاه GOLM، NFRD و NISH که به یکدیگر نزدیک‌اند نشان از یک فرونشست منطقه‌ای دارند. (4) در ایستگاه GRGN علاوه بر فرونشست زیاد، حرکت شتاب‌دار و سیگنال‌های پریودیک بزرگ نیز در مولفه قائم ایستگاه مشاهده شده و لذا لازم است برای آگاهی از علت این رفتار ارتفاعی پوسته زمین، در محدوده این ایستگاه داده‌های بیشتری از طریق نصب ایستگاه‌های دائمی جدید جمع‌آوری شود.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 67
    Publication Date: 2023
    Description: Land surface temperature (LST) plays a key role in the transfer of heat to the atmosphere and to the subsurface layers of soil. This study aims at examining the determination coefficient of MODIS LST on air temperature and soil temperature in different depths of Iran. A new method was employed to create a time consistent LST from Terra and Aqua MODIS products, to eliminate the observation differences in local solar time. Preceding the production of time consistent MODIS LST for 12:30 PM, comparison was carried out with temperature measurements of meteorological stations. The correlation of MODIS LST and Meteorological Station Measurement (hereafter MSM) demonstrate high values, especially for air temperature and 5cm-deep subsurface soil temperature (R2〉0.95). The lowest value was obtained for 100cm-deep soil temperature (R2=0.83). The results of intra annual analysis reveal significant relationship between MODIS LST and MSM temperatures. In the comparison of MODIS LST with subsurface soil temperatures, the scatter plot changes from 1:1 to fusiform due to delay in heat transfer from surface to the subsurface of soil layers. This result postulates that MODIS LST is consonant with MSM temperatures in arid and semiarid regions of Iran. Spatial variation of correlation is higher for 100cm-deep soil temperature (16%). On the contrary, for air temperature and 5cm-deep soil temperature showing the highest correlation, the spatial variation is negligible throughout Iran (6.2%). However, Root Mean Square Error (RMSE) analysis revealed LST differences from 2.43 to 24.88 ˚C throughout Iran rather than MSM temperatures.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 68
    Publication Date: 2023
    Description: این پژوهش چشم‌انداز تغییرات محتمل بارش در 43 ایستگاه هواشناسی کشور را تا انتهای قرن حاضر ارائه می‌کند. برای این منظور، از داده های چهار مدل از نوع ESM به نامهای MIROC6، FGOALS_g3، BCC-CSM2-MR و ACCESS-ESM1-5 از مجموعه مدل‌های سری CMIP6 استفاده شد. برونداد خام بارش توسط نرم افزار CMHyd مقیاس‌کاهی شد. دوره مشاهداتی 2014-1985 و دوره‌های آینده به صورت آینده نزدیک 2050-2026، آینده میانه 2075-2051 و آینده دور 2100-2076 در نظر گرفته شدند. تغییرات بارش در سطح معنی داری 05/0 بر مبنای سه سناریوی SSP1-2.6 ، SSP2-4.5 و SSP5-8.5 بررسی شد. نتایج نشان دادند که تغییرات بارش آینده در حدود 78 درصد از ایستگاهها معنی‌دار نیستند و در 19 و 3 درصد ایستگاهها به ترتیب افزایش و کاهش معنی داری دارند. بیشترین افزایش بارش در جنوب - جنوب‌شرق و بیشترین کاهش در زاگرس مرکزی رخ خواهد داد. میانگین بارش کشور در مقیاس سالانه 0.4 درصد (با دامنه عدم قطعیت 14 درصد) افزایش می یابد. پیش نگری در مقیاس فصلی نشانگر تغییرات ‌ در فصول بهار، تابستان، پاییز و زمستان به ترتیب به مقدار 2/15+، 11- ، 6- و 5/3+ درصد می باشد. اگرچه برای فصل بهار افزایش بارش 2/15 درصدی پیش نگری شده است، اما دامنه تغییرات 9/81 درصدی نشان از بی اعتمادی به بارش های آینده این فصل است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 69
    Publication Date: 2023
    Description: چکیدهبررسی های فعالیت گسل ها مهمترین ابزار برای تعیین جهت‌گیری میدان تنش هستند.با محاسبه سازوکار کانونی زمین لرزه ها جهت انتشار گسیختگی، هندسه گسل و میدان تنش منطقه مورد مطالعه را می توان مشخص نمود. گسل درونه با طول حدود 800 کیلومتر بعد از گسل اصلی زاگرس بزرگترین گسل ایران است. هدف از این پژوهش مطالعه لرزه‌خیزی، حل سازوکار کانونی زمین‌لرزه‌های رخ داده در راستای سه بخش غربی، میانی و شرقی گسل درونه و تخمین تنش در منطقه است. در این مطالعه محاسبه سازوکار کانونی با استفاده از روش پلاریته (قطبش) اولین رسید موج P برای 21 زمینلرزه بزرگتر از 3 رخ داده در مجاورت گسل درونه طی دو دهه اخیر انجام می شود. علاوه بر آن برای راستی آزمائی نتایج از مدل سازی شکل موج برای محاسبه سازوکار کانونی زمینلرزه های کمتر از 4 استفاده می شود. سپس از بررسی سازوکارهای محاسبه شده، مقادیر تنش آزادشده در صفحه‌های گسلی ارائه می‌گردد.سازوکارکانونی رویدادها و مقایسه آن با بررسیهای زمینساختی پیشین در راستای گسل درونه همخوانی قابل قبولی دارد. نتایج مطالعه حاضر نشان می‌دهد تفاوت قابل ملاحظه ای در سازوکار کانونی زمین‌لرزه‌های سه قطعه شرقی، میانی و غربی گسل درونه وجود دارد که تائیدکننده حرکت بلوک‌ها به دوصورت چپ‌بُر و راست‌بُردر راستای گسل است.اختلاف سازوکارکانونی رویدادهای بخش‌های شرقی و غربی با توجه به حرکت رو به شمال بلوک لوت و انحنای گسل درونه توجیه پذیر است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 70
    Publication Date: 2023
    Description: با استفاده از بردارهای سرعت دائم و دوره ای GPS میتوان به تنسور گرادیان جابجایی دست یافت و با محاسبه تنسور کرنش و کمیتهای اسکالر مستخرج از این تنسور به بررسی تغییرشکل قاره ای و تفسیر زمین ساخت منطقه با توجه به گسلهای فعال شناخته شده پرداخت. در این تحقیق برای فلات ایران در محدوده برخورد مایل صفحه های زمین ساختی عربستان و اوراسیا تنسور گرادیان جابجایی با حل مسئله معکوس با استفاده از بردارهای سرعت مسطحاتی GPS محاسبه شد. سپس تنسور کرنش و کمیتهای اسکالر مستخرج از آن یعنی محورهای اصلی کوتاه شدگی و کشیدگی، نرخ دوران حول محور قائم، کرنش برشی بیشینه و اتساع دوبعدی برآورد گردید. نتایج تحلیل با ویژگی‌های زمین‌شناسی بلندمدت در مناطق وسیعی از فلات ایران سازگار است که نشان می‌دهد میدان سرعت GPS منعکس‌کننده فرآیندهای زمین شناسی زمان حاضر فلات ایران است. تغییرات دامنه و جهت دوران حول محور قائم به دلیل تغییرشکل توزیع شده در سرتاسر فلات است. وجود مناطق بزرگ با نرخهای دوران تقریباً ثابت و کم دامنه نشانگر دوران اجسام شبه صلب در داخل فلات برخوردی ایران است که توسط گسلهای فعال احاطه شده اند. دامنه کوتاه شدگی در مناطق داخلی نسبت به مرزهای فلات پایین تر بوده و تقریباً در همه جای فلات نرخ اتساع منفی است. نرخ اتساع منفی با بالاآمدگی قائم پوسته و کوهزایی همراه است. حداکثر مقدار اتساع دوبعدی منفی در بخش جنوبی البرز شرقی برابر 3-^10×8/1 و 3-^10×4/6 در سال به ترتیب با روش های نزدیک ترین همسایگی و فواصل وزن دار محاسبه شد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 71
    Publication Date: 2023
    Description: تنش گرمایی با ترکیب عوامل زیست- هواشناسی متعدد تعیین می‌شود و تأثیرات شدیدی بر سلامت انسانی و اکوسیستم دارد. هدف از این پژوهش بررسی الگوی فضایی تغییرات فصلی تنش گرمایی در ایران با استفاده از شاخص شاخص جهانی اقلیم-گرمایی (UTCI) است. برای این منظور از داده‌هایERA5 از سال 1981 تا 2020 استفاده شد. تغییرات تنش گرمایی فصلی با استفاده از تحلیل شیب سن و آزمون من-کندال تصحیح شده بررسی شد. همچنین برای درستی سنجی داده‌ها سنجه های آماری RMSE، PBIAS، NSE و RSR مورد استفاده قرار گرفت. بررسی فصلی شاخص UTCI نشان داد که این شاخص ناهمگونی منطقه‌ای قابل‌توجهی در ایران دارد. افزایش UTCI از شمال به جنوب ایران منجر به افزایش تنش گرمایی می‌شود. پراکنش فضایی پهنه-هایی که در دوره گرم سال تنش گرمایی ندارند، عمدتاً منطبق با ارتفاعات است. در فصول سرد سال مناطقی با ارتفاع بیش از ۳۰۰۰ متر در ایران دارای تنش سرمایی خفیف تا متوسط هستند. بررسی روند تنش گرمایی طی چهار دهه گذشته که با آزمون من-کندال تصحیح شده مورد بررسی گرفت نشان داد که UTCI در ایران روند غالب افزایشی دارد. شاخصUTCI در فصول بهار و پاییز در ۱۰۰ درصد و فصول زمستان و تابستان به‌ترتیب در ۹۹.۸۳ و ۹۹.۷۵ درصد از کشور روند افزایشی را نشان می دهد. بیشینه روند افزایشی معنی‌دار شاخص در سطح ۰.۰۵ در فصل بهار ۹۸.۰۲ به‌دست آمده است. به‌همین ترتیب بالاترین مقدار شیب روند متوسط‌ پهنه‌ای کشور نیز با مقدار ۰.۵۲ درجه‌سلسیوس در همین فصل دیده می‌شود که در سطح آلفا ۵ درصد معنی‌دار است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 72
    Publication Date: 2023
    Description: مطالعه هندسه سنگ بستر در اکتشافات معدنی و نفتی جهت دست‌یابی به تصاویر دو بعدی از آن، مستلزم استفاده از محاسبات وارون غیرخطی است. الگوریتم‌های مورد استفاده در این مطالعه، الگوریتم ژنتیک مرتب‌سازی نامغلوب NSGA-II و الگوریتم ژنتیک GA است که جهت محاسبات برآورد عمق مورد استفاده قرار گرفته است. الگوریتم ژنتیک مرتب‌سازی نامغلوب برای حل مسائلی با توابع هدف متعدد و عموماً متعارض که از قابلیت توسعه و توانایی بالایی در حل مسائل چند هدفه نامقید برخوردار است. الگوریتم ژنتیک تک‌هدفه نیز قابلیت مدل‌سازی را دارد. در این مطالعه، جهت راستی‌آزمایی و صحت‌سنجی هر دو الگوریتم، از داده‌های تولید شده توسط یک مدل مصنوعی پیچیده استفاده شد و برای بررسی دقیق‌تر عملکرد این الگوریتم‌ها از این داده‌ها در دو شرایط بدون نوفه و همراه با نوفه سفید گوسی تا 10% مورد مطالعه و بررسی قرار گرفت و نتایج حاصل از مدل‌سازی توسط این الگوریتم‌ها تطابق قابل قبولی را با مدل اولیه ارائه داد به طوری که در الگوریتم NSGA-II پارامتر ریشه میانگین مربع خطا (RMS)برای داده بدست آمده از داده اولیه مدل مصنوعی از 0.05 تا 0.35 میلی‌گال و در الگوریتم GA از 0.07 تا 0.52 میلی‌گال است. این پارامتر در الگوریتم NSGA-II برای مدل بدست آمده از مدل اولیه 72.4 متر و برای الگوریتم GAاز 93.8 متر بالا نرفت. با بررسی مدل‌سازی گرانی‌سنجی محدوده آناتولی در کشور ترکیه، نتایج بدست آمده برای هر دو الگوریتم با ایجاد شرایط مشابه از نظر تنظیم پارامتری و تعداد دفعات اجرای الگوریتم، نشان‌دهنده عملکرد مناسب الگوریتم NSGA-II نسبت به الگوریتمGA است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 73
    Publication Date: 2023
    Description: در این مقاله مقدار محتوای الکترون کلی (TEC) یونسفر با مدل‌های یادگیری ماشین (ML)، به صورت مکانی-زمانی، مدل‌سازی شده و مورد ارزیابی و مقایسه قرار می‌گیرد. روش‌های رگرسیون بردار پشتیبان (SVR) و شبکه عصبی مصنوعی (ANN) جهت مدل‌سازی محلی TEC استفاده می‌شوند. نوآوری اصلی این مقاله در ارزیابی تاثیر پارامترهای فیزیکی مختلف (KP، AP، DST و F10.7) در دقت خروجی مدل‌های یادگیری ماشین است. نتایج بدست آمده از دو مدل جدید با نتایج مدل جهانی یونسفری (GIM)، مدل‌های تجربی IRI2016 و NeQuick در دو ایستگاه کنترل داخلی و یک ایستگاه کنترل خارجی مورد مقایسه قرار گرفته‌اند. شاخص‌های آماری جذر خطای مربعی میانگین (RMSE)، خطای نسبی، dVTEC=|VTECGPS-VECmodel| و ضریب همبستگی برای ارزیابی خطای مدل‌ها، بکار گرفته شده است. ارزیابی تاثیر پارامترهای ژئومغناطیسی و خورشیدی در خروجی مدل‌های SVR و ANN نسبت به پارامترهای ورودی انجام و اهمیت هر کدام از پارامترهای فیزیکی در مدل‌سازی مکانی-زمانی یونسفر مورد بررسی قرار گرفته است. میانگین RMSE محاسبه شده در دو ایستگاه کنترل داخلی برای مدل‌های SVR، ANN، GIM، IRI2016 و NeQuick به ترتیب برابر با 04/1، 91/3، 0.2/3، 90/6 و 65/7 TECU شده است. همچنین میانگین ضریب همبستگی مدل‌ها در دو ایستگاه کنترل داخلی به ترتیب برابر با 97/0، 72/0، 84/0، 68/0 و 60/0 محاسبه شده است. نتایج بدست آمده از این مقاله نشان می‌دهد که در هر دو حالت فعالیت‌های ژئومغناطیسی و خورشیدی بالا و پایین، مدل SVR در ایستگاه‌های کنترل داخلی از دقت و صحت بالاتری نسبت به سایر مدل‌ها برخوردار است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 74
    Publication Date: 2023
    Description: روش‌های ترکیبی برای تعیین عمق موهو در نبود نقاط لرزه‌ای با چگالی و پوشش مناسب عمدتاً در مطالعات ژئوفیزیک، ژئودزی مورد استفاده قرار می‌گیرد. در میان این روش‌ها می‌توان به روش پارکر-اولدنبرگ و ونینگ ماینتز مورتس اشاره کرد. با هدف بهبود مدل‌های موجود عمق موهو در پهنه فرورانشی مکران به عنوان یک منطقه با زمین ساخت پیچیده، دو مدل مختلف به نامهایBC وSC با روش ترکیبی ثقلی- لرزه‌ای توسعه داده شد. داده‌های جهانی(CRUST1.0) و مدل ونینگ ماینز موریتس Vening Meinesz-Mortiz (VMM) به ترتیب به عنوان داده‌های لرزه‌ای و گرانشی، به روشی مناسب و با دو رویکرد فیلتر و ترکیب طیفی و استفاده از سرشکنی کمترین مربعات مورد استفاده قرار گرفته است. مدل‌های بدست آمده دارای وضوح '5×'5 درجه معادل شبکه‌ای با ابعاد حدود 9×9 کیلومتر هستند. دقت موهو بدست آمده با چهار مدل مختلف منطقه‌ای و محلی ارزیابی گردید. RMS نتایج بدست آمده به ترتیب92/2، 75/1، 85/4 و 27/1 کیلومتر برای مدلBC و41/2، 41/0 ، 48/4 و 04/3 کیلومتر برای مدل SC است. مدل عمق موهو بدست آمده برای مکران غربی در ایران و اطراف آن به میزان قابل ملاحظه‌ای وضوح، دقت و قدرت تفکیک مدل-های عمق موهو را در منطقه مورد مطالعه بهبود داده است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 75
    Publication Date: 2023
    Description: در این تحقیق از روش گرادیان کامل نرمال جهت ارائه مدل زیر سطحی یک خط برداشت بی‌هنجاری بوگه با طول بیش از 400 کیلومتر در شمال‌غرب ایران استفاده شده است، مهمترین ساختارهای واقع بر این خط برداشت از غرب به شرق؛ سهند، گسل شمال تبریز و سبلان است. برای ارائه مدل کلی از ساختار زیرسطحیِ منشا بی‌هنجاری در مقیاس لیتوسفیر در شمال‌غرب ایران، از داده-های مدل مصنوعی برای مطالعه قدرت بازیابی روش گرادیان کامل نرمال استفاده شده است. نتایج استفاده از مدل مصنوعی نشان می‌دهد که گرادیان کامل نرمال می‌تواند ساختار کلی لیتوسفیر با تباین چگالی مناسب را بازیابی کند. با توجه به نتایج بدست آمده از خط برداشت مورد مطالعه از روش گرادیان کامل نرمال در شمال‌غرب ایران، ناحیه بین سهند، گسل شمال تبریز و سبلان شدیداً متاثر از گوه‌ای احتمالاً کم‌‌چگال با عرض بیش از 50 کیلومتر، مدفون در عمق بیش از 40 کیلومتر می‌باشد که کم‌عمق‌ترین پاسخ آن زیر گسل شمال تبریز است. بر اساس مدل به دست آمده، سبلان و سهند نیز به تناسب شکل قرارگیری گوه تحت تاثیر این ساختار عمیق قرار گرفته‌اند. این اثر برای عمق‌های کمتر از 40 کیلومتر با شدت بیشتری برای سبلان و با شدت کمتری برای سهند در مدل گرادیان کامل نرمال بازیابی شده است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 76
    Publication Date: 2023
    Description: Due to increasing the population in metropolitan regions such as Tehran and the existence of the underground constructions, the importance of seismic investigation is evident to reduce damages caused by probable earthquakes. Accordingly, the precise detection of micro to medium earthquakes is effective tool for tracking fault dynamics in seismic cycles, as well as for earthquake prediction and seismic hazard assessment. In this study, the recorded ambient noise at Tehran Disaster Mitigation and Management Organization (TDMMO) and Road, Housing and Urban Development Research Center (BHRC) networks, as an accelerometer network installed in Tehran city, have been used on the point of characterizing the noise spectrum for each station as a function of time for obtaining the detection threshold of these networks. Therefore, an indirect approach based on the signal-to-noise ratio (SNR) in the time domain, with parameterization in the frequency domain is applied. Based on SNR method, the source signature is simulated by a simple source model called a circular fault model. So the signal is estimated via the Brune function as a most common models for circular faults. While, to determine the noise, the real data of 13 accelerometer stations of the TDMMO and 7 joint stations with the BHRC were used. In this respect, the Power Spectral Density (PSD) of noise was calculated using PQLX software in the frequency domain and then transferred to the time domain by the Parsville theorem. Eventually, the SNR value was acquired for each station by dividing these two quantities. As a result, the minimum detectable magnitude in at least five stations with an SNR larger than five is 3.0 for S-waves and 3.3 for P-waves, which frequently occurs in the center of the network.Another finding of this studies is to analyze the effect of spatial variations of the noise on the detection ability. For this, a constant noise was allotted to all stations, lowest observed noise level, as a result of which, the smallest magnitude detectable is 1.7 for S waves and 2.2 for P waves.At last, the sensitivity of the detection capability to 3 fundamental parameters, including stress drop, focal depth and reduced time, which were assumed as a constant value within the network, were investigated. In fact, these parameters are strongly affected by uncertainty and aren't absolute values. Consequently, the impact of their changes was studied. In our case, implied that the variation in the stress drop has no effect on the detection threshold, but the focal depth and the reduced time are effectual. A 15 km variations in the focal depth, the detectable magnitude changes by 0.3 units, and by changing the reduced time from 0.015 to 0.035 s, the detectable magnitude varies by 0.4 units in Mw.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 77
    Publication Date: 2023
    Description: در این پژوهش با هدف بررسی نحوه توزیع سالانه و فصلی گردوخاک در استان گلستان و نحوه تاثیرپذیری آن از بیابان‌های ترکمنستان، نمودار تعداد روزهای همراه با گردوخاک با استفاده از داده‌های AOD (دارای همبستگی 66/0 با داده‌های دید افقی ایستگاه‌های همدیدی) بزرگتر از 5/0 سنجنده MODIS، در بازه زمانی 2020-2000 مورد مطالعه و همچنین نقشه تغییرات مکانی تعداد روزهای همراه با گردوخاک بررسی گردید. به منظور بررسی شدت تأثیرپذیری استان گلستان از بیابان‌های ترکمنستان علاوه بر رهگیری مسیر انتقال گردوخاک با استفاده از خروجی مدل HYSPLIT برای یک رویداد منتخب از هر فصل، تحلیل همدیدی توسط داده‌های ERA5، نیز انجام شد. شرایط همدیدی در روز منتخب از هر فصل بیان‌گر جریانات شمالی و وزش باد قابل توجه در منطقه بیابانی واقع در شرق دریای خزر است که این مطلب موجب خیزش خاک در بیابان‌های ترکمنستان و انتقال آن می‌گردد و با استقرار پشته در تراز میانی وردسپهر، ماندگاری بیشتر گردوخاک رخ می‌دهد. بر اساس نتایج به‌دست آمده در حقیقت دو بازه زمانی با رخداد کم (سال‌های 2000 تا 2007 (به جز سال 2003) و سال‌های 2016 تا 2020) و یک بازه زمانی با رخداد زیاد (سال 2008 تا 2015) وجود دارد که رابطه مستقیمی بین افزایش گردوخاک در بیابان‌های ترکمنستان و استان گلستان وجود دارد. در طول دوره آماری بیشترین مقدار AOD در هفتم سپتامبر سال 2020 با مقدار 1/4 رخ داده است. رهگیری مسیر انتقال گردوخاک با استفاده از خروجی مدل HYSPLIT نشان داد که منشأ عمده گردوخاک استان از مناطق بیابانی ترکمنستان و خصوصاً بیابان‌های بالکان می‌باشد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 78
    Publication Date: 2023
    Description: روش سونداژ تشدید مغناطیسی (Magnetic Resonance Sounding) که به اختصار MRS نامیده می‌شود، به عنوان یک روش ژئوفیزیکی سطحی اطلاعات مناسبی درباره‌ی پارامترهای هیدروژئوفیزیکی (مانند محتوای آب و هدایت هیدرولیکی) لایه های آبخوان ارائه می‌دهد. با وجود کارایی بسیار این روش، سیگنال ثبت شده با این شیوه، به شدت تحت تاثیر نوفه‌های الکترومغناطیسی از جمله نوفه‌های هارمونیکی‌و نوفه‌های اسپایکی قرار می‌گیرد. در این مقاله برای آن که بتوان برآورد درستی از پارامترهای سیگنال MRS به‌دست آورد، روشی برای حذف نوفه‌های هارمونیکی در حوزه زمان ارائه می‌شود. سیگنال های مصنوعی به منظور بررسی تاثیر پارامترهای گوناگون بهینه‌ی فیلتر، برای روش‌های حذف رویدادهای اسپایکی و هارمونیکی شرح داده شده و ارزیابی می‌گردند.مبحث جدیدی که در این مقاله دنبال می شود بررسی کارایی الگوریتم پیشنهادی در مواقعی است، که سیگنال هارمونیکی دارای فرکانس پایه متغیر با زمان می‌باشد. پیش از به‌کاربردن الگوریتم حذف نوفه‌های هارمونیکی، می‌بایست سیگنال‌های اسپایکی حذف و یا تا اندازه‌ی ممکن کاهش داده‌ شوند. بنابراین نخست، یک الگوریتم پردازشی آماری براساس روش SD-ROM برای حذف نوفه‌های اسپایکی ارائه می‌گردد و پس از آن، روشی برای حذف نوفه‌های هارمونیکی، با فرض بسامد پایه ثابت و متغیر با زمان، بر اساس لوپ مرجع راه دور و با به‌کارگیری توابع انتقال ارائه می‌شود. نتایج عددی به‌کارگیری الگوریتم های پردازشی پیشنهادی در حوزه زمان نشان می‌دهد که از طریق کاربست روش‌های یاد‌شده، سیگنال های اسپایکی و هارمونیکی تا اندازه‌ی چشم‌گیری حذف می شوند و بنابراین به برآورد مناسبی از پارامترهای سیگنال MRS (دامنه اولیه‌ی، زمان آسایش، فاز و بسامد سیگنال) می‌انجامد.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 79
    Publication Date: 2023
    Description: به‌دلیل عدم‌وجود اطلاعات کافی در مورد چگالی اجرام زیرسطحی، در مدل‌سازی میدان گرانی زمین، معمولاً از میانگین جهانی چگالی به‌صورت عددی ثابت در کل منطقه موردمطالعه استفاده می‌شود. در حالی‌که، افزایش دقت تقریب چگالی در مدل‌سازی اثر گرانش ناشی از جرم توپوگرافی، دقت مدل‌سازی میدان گرانی را بالاتر خواهد برد. برای امکان‌سنجی این موضوع، از یک مدل چگالی توپوگرافی با قدرت تفکیک "30×"30 که از پردازش نقشه‌های لرزه‌نگاری و اطلاعات ماهواره‌ای لایه‌های لیتوسفر تهیه شده، برای افزایش دقت تقریب چگالی ثابت در چهار منطقه مطالعاتی درون ایران با وضعیت توپوگرافی و پراکندگی داده متفاوت استفاده شده است. به این ترتیب که، علاوه بر مقدار میانگین جهانی، مقدار میانگین چگالی در ایران و منطقه نیز در مدل‌سازی اثر گرانش ناشی از جرم توپوگرافی لحاظ شد. در مدل‌سازی میدان گرانی، روش کالوکیشن کم‌ترین مربعات و به‌تبع، تکنیک RTM در مدل‌سازی اثر گرانش ناشی از جرم توپوگرافی به‌کار گرفته شد. همچنین، افزون بر اصلاح چگالی، استفاده از رویکرد کوواریانس بهبودیافته در مدل‌سازی میدان گرانی نیز مورد ارزیابی واقع شد. نتایج مقایسه با نقاط کنترلی این پژوهش نشان می‌دهد، به‌کارگیری اصلاح چگالی و رویکرد کوواریانس بهبودیافته در مناطق با توپوگرافی خشن و فاقد داده گرانی‌سنجی کافی و پراکندگی مناسب، به‌شکل قابل‌اعتنایی (88/1 میلی‌گال معادل %15.6 در منطقه مطالعاتی این پژوهش) باعث افزایش دقت مدل‌سازی میدان گرانی می‌شود.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 80
    Publication Date: 2023
    Description: دریای عمان، محل تلاقی دو صفحه تکتونیک اورآسیا و عربی و منطقه فرورانش مکران است. با وجود آنکه اطلاع از رفتار و تغییرات محلی میدان گرانی، در مطالعه و مدل‌سازی ساختار پیچیده زمین‌ساختی در این‌محدوده از اهمیت بالایی برخوردار است، تاکنون کم‌تر به‌آن پرداخته شده است. در این‌پژوهش، از مشاهدات ماهواره‌ای SARAL/AltiKa استفاده شده است که به‌دلیل اندازه‌گیری در باند فرکانسی Ka، قدرت تفکیک مکانی و در نتیجه، ‌دقت ارتفاعی بالاتری نسبت به‌دیگر ماموریت‌های ارتفاع‌سنجی ماهواره‌ای دارد. از طرف دیگر، در اکثر روش‌های مورد استفاده در مدل‌سازی میدان گرانی زمین، برای ساده‌سازی محاسبات، دو فرض ایستایی و هم‌سان‌گردی میدان گرانی لحاظ می‌شود که این دو فرض به معنای عدم وابستگی تابع گرانی به تغییرات آزیموت و موقعیت مشاهدات و نقاط داخل میدان بوده که چنین فرضی، هم‌واره برقرار نیست. در این تحقیق، از روی‌کرد کووریانس بهبودیافته برای افزایش دقت تعیین کووریانس و ایده ناحیه‌بندی، به‌عنوان راه‌حلی برای کاهش اثرات منفی فرض ایستایی و هم‌سانگردی در مدل‌سازی محلی میدان گرانی استفاده شده است. نتایج این‌پژوهش در 234 نقطه گرانی‌سنجی دریایی کنترل و مشخص شد که به‌کارگیری کووریانس بهبودیافته و ناحیه‌بندی، منجر به‌افزایش بیش از %39 (1.6 میلی‌گال) دقت مدل‌سازی محلی میدان گرانی به‌روش کالوکیشن کم‌ترین مربعات در دریای عمان می‌شود. دقت حاصل ازمدل‌سازی محلی، در بعضی نواحی منطقه، تا %11.3 (0.33 میلی‌گال) بالاتر از مدل‌های جهانی گرانی است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 81
    Publication Date: 2023
    Description: With the development of linked data technologies and launch of the Bibliographic Framework Initiative (BIBFRAME), the library community has conducted several experiments to design and build linked data editors. While efforts have been made to create original linked data 'records' from scratch, less attention has been given to copy cataloging workflows in a linked data environment. Developed and released as an open-source application in 2015, Metadata Maker is a cataloging creation tool that allows users to create bibliographic metadata without previous knowledge in cataloging. Metadata Maker might have the potential to be adopted by paraprofessional catalogers in practice with new linked data sources added, including auto suggestion of Virtual International Authority File (VIAF) personal name and Library of Congress Subject Heading (LCSH) recommendations based on the users’ text input. This article introduces those new features, shares the user testing results, and discusses the possible future steps.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 82
    Publication Date: 2023
    Description: E-lecturing and online learning are more common and convenient than offline teaching and classroom learning in the academic community after the covid-19 pandemic. Universities and research institutions are recording the lecture videos delivered by the faculty members and archiving them internally. Most of the lecture videos are hosted on popular video-sharing platforms creating private channels. The students access published lecture videos independent of time and location. Searching becomes difficult from large video repositories for students as search is restricted on metadata. We presented a design and developed an open-source application to build an education lecture archive with fast and full-text search within the video content.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 83
    facet.materialart.
    Unknown
    In:  Code4Lib Journal
    Publication Date: 2023
    Description: At the Kingsborough Community College library, we recently decided to bring the library’s website more in line with DRY principles (Don’t Repeat Yourself). We felt we this could improve the site by creating more concise and maintainable code. DRYer code would be easier to read, understand and edit. We adopted the Vue.js framework in order to replace repetitive, hand-coded dropdown menus with programmatically generated markup. Using Vue allowed us to greatly simplify the HTML documents, while also improving maintainability.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 84
    Publication Date: 2023
    Description: This article details the changes made to the queueing system used by Virginia Tech University Libraries' 3D Design Studio as the space was decommissioned and reabsorbed into the new Prototyping Studio makerspace. This new service, with its greatly expanded machine and tool offerings, required a revamp of the underlying data structure and was an opportunity to rethink the React and Electron app used previously in order to make the queue more maintainable and easier to deploy moving forward. The new Prototyping Queue application utilizes modular design and auto building forms and queues in order to improve the upgradeability of the app. We also moved away from using React and Electron and made a web app that loads from the local filesystem of the computer in the studio and runs on the Svelte framework with IBM's Carbon Design components to build out functionality with the frontend. The deployment process was also streamlined, now relying on git and Windows Batch scripts to automate updating the app as changes are committed to the repository.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 85
    facet.materialart.
    Unknown
    In:  Code4Lib Journal
    Publication Date: 2023
    Description: This article introduces practices at the library of Oregon State University aiming to track the usage of Unpaywall links with Google Tag Manager for the Primo discovery interface. Unpaywall is an open database of links to full-text scholarly articles from open access sources[〈a href="https://journal.code4lib.org/#note1"〉1〈/a〉]. The university library adds Unpaywall links to Primo that will provide free and legal full-text access to journal articles to the patrons to promote more usage of open-access content. However, the usage of the Unpaywall links is unavailable because Primo does not track the customized Unpaywall links. This article will detail how to set up Google Tag Manager for tracking the usage of Unpaywall links and creating reports in Google Analytics. It provides step-by-step instructions, screenshots, and code snippets so the readers can customize the solution for their integrated library systems.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 86
    facet.materialart.
    Unknown
    In:  Code4Lib Journal
    Publication Date: 2023
    Description: Journal updates, recent policies, and a call for editors.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 87
    facet.materialart.
    Unknown
    In:  Code4Lib Journal
    Publication Date: 2023
    Description: An increasing challenge libraries face is how to maintain and synchronize the electronic resource records from vendors with those in the integrated library system (ILS). Ideally vendors send record updates frequently to the library. However, this is not a perfect solution, and over time a problem with record discrepancies can become severe with thousands of records out of sync. This is what happened when, at a certain point, our acquisitions librarian and our cataloging librarian noticed a big record discrepancy issue. In order to effectively identify the problematic records among tens of thousands of records from both sides, the author of this article developed some solutions to analyze the data using Python functions and scripts. This data analysis helps to quickly scale down the issue and reduce the cataloging effort.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 88
    Publication Date: 2023
    Description: Archival description is often misunderstood by librarians, administrators, and technologists in ways that have seriously hindered the development of access and discovery systems. It is not widely understood that there is currently no off-the-shelf system that provides discovery and access to digital materials using archival methods. This article is an overview of the core differences between archival and bibliographic description, and discusses how to design access systems for born-digital and digitized materials using the affordances of archival metadata. It offers a custom indexer as a working example that adds the full text of digital content to an Arclight instance and argues that the extensibility of archival description makes it a perfect match for automated description. Finally, it argues that building archives-first discovery systems allows us to use our descriptive labor more thoughtfully, better enable digitization on demand, and overall make a larger volume of cultural heritage materials available online.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 89
    Publication Date: 2023
    Description: This article aims to demystify data preparation and machine-learning software for sequence-to-sequence models in the field of computational linguistics. The tools, however, may be used in many different applications. In this article we detail what sequence-to-sequence learning looks like using code and results from different projects: predicting pronunciation in Esperanto, predicting the placement of stress in Russian, and how open data like WikiPron (mined pronunciation data from Wiktionary) makes projects like these possible. With scraped data, projects can be started in automatic speech recognition, text-to-speech tasks, and computer-assisted language-learning for under-resourced and under-researched languages. We will explain why and how datasets are split into training, development, and test sets. The article will discuss how to add features (i.e. properties of the target word that may or may not help in prediction). By scaffolding the tasks and using code and results from these projects, it’s our hope that the article will demystify some of the technical jargon and methods.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 90
    Publication Date: 2023
    Description: The proposed software solution is a tool developed for the analysis, forecast and visualization of geophysical data, which is collected and provided by a set of spatially distributed heterogeneous data repositories via standard web protocols (HTTP, HTTPs, FTP, etc.). They include ground magnetic observatories and stations, satellites, as well as various numerical models based on geophysical standards and specifications. The technological stack is limited with the tool’s web-based implementation and represented by integrated client- and server-side technologies with specialized frameworks and APIs. Client-side implementation is represented by several markup, styling and interaction software technologies, which are HTML5/CSS3/JavaScript with geospatial ESRI ArcGIS API for JavaScript available as the RESTful resources. Django web framework based on the “Model – View – Controller” architectural model represents server-side implementation, where Python is the main programming language used for the application’s business logic. The complete Web-based GIS represents a web portal with a set of services providing a rich instrumentation for the appropriate geophysical data analysis, processing, and visualization. Each tool upon execution provides an interactive geospatial image, which is generated according to the user request parameters or by default date-time settings. The proposed web services are freely available at https://aurora-forecast.ru and https://geomagnetic.ru through the web browsers.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 91
    Publication Date: 2023
    Description: با توجه به کاربرد نوفه‌های لرزه‌ای محیطی در دهه‌های اخیر بعنوان ابزاری کم هزینه برای مطالعه ساختار زیرسطحی و تحلیل خطر، زلزله‌شناسی شهری به یک زمینه تحقیقاتی فعال تبدیل شده است. از این رو از زلزله‌شناسی شهری در کلان‌شهر تهران استفاده شده است. این شهر در دامنه جنوبی کوه‌های البرز مرکزی و بر روی نهشته‌های آبرفتی کواترنر بنا شده و قسمت جنوبی آن در کناره شمال باختری کویر بزرگ ایران مرکزی قرار دارد و توسط گسل‌های فعالی چون گسل مشاء، گسل شمال تهران و گسل جنوب ری محصور شده است. بنابراین با توجه به وجود تراکم بالایی از ارتعاشات ناشی از فعالیت‌های انسانی در شهر تهران و همچنین وجود ساختارهای زیرسطحی در این شهر، اهمیت زلزله‌شناسی شهری و روش‌های مبتنی بر نوفه‌های لرزه‌ای محیطی مبرهن است. در این مطالعه با استفاده از داده‌های دو شبکه شتابنگاری تهران و روش چگالی طیف توان- تابع چگالی احتمال به بررسی تغییرات مکانی و زمانی نوفه‌های لرزه‌ای محیطی در حوزه فرکانس و همچنین تاثیر همه‌گیری ویروس کرونا بر سطح نوفه‌ها در حوزه زمان و فرکانس پرداخته شده است.نهایتا، بازه زمانی 4:30-3:30 صبح بعنوان ساعت مرتبط با کمترین سطح نوفه در سه بازه فرکانسی مرتبط با حرکت انسانی، ترافیک و مترو بدست آمد و برای تغییرات مکانی نیز ایستگاه D011 همواره کمترین سطح نوفه را در هر سه بازه فرکانسی ثبت کرده است. علاوه بر این، بررسی‌های انجام گرفته در خصوص تغییرات سطح نوفه در دوران کرونا کاهشی در حدود 4-1٪ و افزایشی در حدود 15-1٪ ثبت کرده است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 92
    Publication Date: 2023
    Description: .In this work the longitudinal variations of equatorial electrojet (EEJ) and its effect on the diurnal behavior of the EIA during quiet days in the period of 2011- 2012 were investigated. EEJ has been estimated using pair of ground-based magnetometers data from six longitudinal sectors and the Global Positioning System (GPS) TEC have been also obtained at each longitudinal sector from three stations at Northern and Southern crests and trough regions. The statistical results shows, the monthly mean variations of EIA crest are consistent with that of the strength of equatorial electrojet in most regions of the investigation. The mean EEJ and EIA crests are strongest around equinoctial months in the Peruvian and Southeast Asian sectors followed by the West African regions throughout the years investigated. The weakest EEJ peaks and TEC of EIA are observed over the Pacific sectors throughout the periods of investigation. The monthly mean characteristics of EEJ/counter electrojets (CEJ) and EIA are also presented. The results also shown that the CEJ events occur more frequent in the Brazilian sectors followed by in the Peruvian and West African sectors. However, in most of the equinoctial months, the strongest equatorial EIA trough and weakest of EIA crests are observed in the Brazilian sector. The temporal extent of the well-developed EIA crest and its properties have shown a substantial dependence on the diurnal characteristics of the EEJ for each specific day.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 93
    Publication Date: 2023
    Description: جریان شکافنده از جمله مهمترین پدیدههای مطرح در مناطق ساحلی است که علاوه بر تاثیرات فیزیکی قابل توجه در منطقه ساحلی، عامل بخش قابل توجهی از مرگ و میرها و حوداث دریایی است. به همین دلیل این جریان توسط گروهی از محققان بین المللی از جنبه های مختلف مورد توجه قرار گرفته است. در این تحقیق سعی شده است با نمونه برداری از رسوبات کف کانال جریان شکافنده و محیط اطراف آن در سواحل دریای خزر، تاثیر جریان شکافنده بر دانه بندی این رسوبات مشخص گردد. نمونه برداری بصورت ماهانه در دو فصل زمستان و بهار انجام گرفت. برای مقایسه ویژگیهای رسوب در کانال ریپ و پشته‌های اطراف آن از آزمون تی تست غیر زوجی استفاده شد و اختلاف معنی داری در سطح 95% مشاهده گردید. نتایج گرانولومتری نشان داد که تفکیک داده ها به دو فصل زمستان و بهار نشان‌دهنده‌ی تفاوت معنی دار قطر میانه، میانگین اندازه ذرات و چولگی توزیع ذرات رسوب در کانال جریان شکافنده نسبت به محیط اطراف آن در فصل بهار شد. در فصل زمستان احتمالا به دلیل آشفتگی آب و هوا و تلاطم در جریانات دریایی و امواج مرتفع حاصل از وزش بادهای شدید تفاوت مقدار این پارامترها در داخل کانال شکافنده و محیط اطراف آن معنی دار نبوده است.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 94
    Publication Date: 2023
    Description: 〈p〉〈em〉Landuse play a role in the determination of main’s social, economic, and cultural progress. In general, the idea of land use is connected to the local physical environment. Landuse reflect a complex correlation between natural historical and socio-economic factors. Besides, size of holding and caste structure determine the changing of land use on the agricultural crops. Such as undulating terrain and hilly poor land determine the process of farming and as-well-as sometime at the capacity of farmers. The present study characteristics of changing pattern of land use in the Sagar district. Slightly more-than half (52.64%) of the total geographical area is net sown in 2021. This proportion is higher than the 48.93% statewide average. An additional 2.29% of the total area is made up of fallow areas. As a consequence, around 75% of the land had farmed. The forest land (24.46%) is quite similar to the average distribution. Around 1.69% of the area is designated as barren and uncultivable due to physical limitations. For a number of reasons, other uncultivated land accounts for about 10.65% of the total area. Land use patterns are influenced by cropping practices and intensity of farming as well as human social and economic position, institutional makeup, and technology advancements. The terrain of its land is ridged on a big chunk of it. Therefore, regional balances of natural processes within them are crucial prerequisites for the rising population's access to food security and its ability to get the most out of the resources at hand.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 95
    Publication Date: 2023
    Description: 〈p〉〈em〉The ruling aspect of the present investigation is to study the textural characters as well as to understand the grain size relationship and distributionby engaging granulometric analysis, along the Pennar estuary, South east coast of India. An aggregate of 36 Surface sediment samples were retrieved and a comprehensive study of textural parameters and various size distribution of sediments were analysed at six various stations in six different micro – environments viz., dune, backshore, berm, upper foreshore (UFS), middle foreshore (MFS) and lower foreshore (LFS).  These were further subjected to statistical treatment viz., Mean size (Mz), Skewness (Sk), Standard deviation (σ〈strong〉〈sub〉I〈/sub〉〈/strong〉), and Kurtosis (K〈sub〉G〈/sub〉). The procured results indicates that the sediment samples were coarse to fine grained, very negatively skewed to positively skewed, very well to moderately sorted, and platy tovery leptokurtic in nature and also indicates two mixed environments at some stations. Scatter plots were help to understand the mode of deposition, geological significance and transportation of grains along the coast. Scatter plots also divulges that the sediments along the coast were mainly associated with fluvial process. C-M diagrams demonstrate the type of transportation and deposition of the beach sediments. Ebbing and flooding shows prominent role in changing the characteristics of grains in the Pennar estuary, especially in the estuarine mouth and adjoining river areas.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 96
    Publication Date: 2023
    Description: 〈p〉〈em〉〈span〉Currently, wind and solar power generation systems have many drawbacks. Wind and solar power generation Full use of new energy will break the barrier to growth. Location for wind/solar hybrid power plant the primary problem is how to choose scientifically. This article selects six wind/solar hybrid power plants and implements them as a case study and evaluates these six areas via VIKOR by weighting the indicators through the MCDM method. Conclusions Related research findings and better valid, this demonstrates the feasibility and effectiveness of the method. This macro-site selection plants may provide some theoretical basis. In this statistical methods in the literature and established by statistical analysis. Tamil Nadu, Rajasthan, Maharashtra, Gujarat, Andhra Pradesh, Karnataka taken this alternative in this method and evaluation parameters are Total investment, Wind direction, Wind speed and speed change, sunshine stabilization, wind power density, energy saving, Environmental factors. Gujarat is on 2nd rank, Rajasthan is on the 1st rank, Tamil Nadu is on the 3rd rank, Indian Karnataka is on the 4th rank, Maharashtra is on the 5th rank and finally Andhra Pradesh is on the 6th rank.〈/span〉〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 97
    Publication Date: 2023
    Description: The current study compares the effect of dust aerosols on two meteorological variables, temperature and relative humidity, in two different regions. For this purpose, AOD data from the Moderate Resolution Imaging Spectroradiometer (MODIS) were used for Kermanshah and Ahvaz from 2010 to 2015. In a subjective review, a day with the highest AOD value was highlighted. The effect of dust on temperature and relative humidity variations were investigated on the selected day and compered with a clean day. The effect of aerosols on the vertical profile of temperature shows that increasing aerosol concentrations in Kermanshah causes a rise in temperature at lower atmosphere during the day due to absorption of solar radiation by the dust aerosols and a decrease in temperature at night due to longwave radiative cooling. Because of the high seasonal humidity in Ahvaz, the nature of the aerosols has changed, resulting in the greenhouse effect, which has raised the temperature by absorbing radiation at night. The effect of aerosols on the vertical profile of relative humidity differs between Kermanshah and Ahvaz. The relative humidity has risen, particularly at lower levels in Ahvaz during the dusty days and nights. The increase in aerosols in both the Ahvaz and Kermanshah regions had no effect on precipitation based on data from the Iran Meteorological Organization. The reason could be a lack of precipitating systems in the two regions during the warm seasons.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 98
    Publication Date: 2023
    Description: 〈div class="enclosure"〉〈/div〉
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 99
    Publication Date: 2023
    Description: While Surface Heat Flow (SHF) is an important indicator of the hydrocarbon reservoirs and mineral potentials, the measurements over the Iranian plateau are very sparse. In light of accessing the crustal and lithospheric structure derived from a well-constrained geophysical-petrological model, this study provides a 3D SHF, Curie depth isotherm (580 ºC), Moho temperature and low-temperature sedimentary basins (〈150 ºC) over the Iranian plateau and surrounding areas. We solve heat transfer equation using certain thermal boundary condition and user-defined thermophysical parameters for crust. Thermal conductivity of the lithosphere is calculated iteratively. Our results indicate that the iron deposits (within the igneous provinces) are spatially correlated with highs in the 3D map of SHF (〉60 mW/m2), the shallow Curie isotherm (〈40 km) and warm Moho boundary (〉800 ºC) where lithospheric thinning or crustal thickening occurs. SHF highs are observed in the northern part of the Zagros collision zone, Central Iran micro-continent and Kopeh Dagh. The low-temperature sedimentary basins (〈150 ºC) are illustrated by the lows in the 3D map of SHF (〈60 mW/m2), deep Curie isotherm (〉40 km), and cold Moho boundary (〈800 ºC) where lithosphere thickening or crustal thinning is taken place. These basins are distributed in the Oman Sea, Persian Gulf, northern margin of the Arabian plate (Mesopotamian foreland basin), the Caspian Sea and Turan platform.
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 100
    Publication Date: 2023
    Description: 〈p〉〈em〉Flood hazard mapping, which uses model and satellite remote sensing data, is extremely useful for flood monitoring and risk management. The flood inundation extent and flooding depth on Majuli Island and its surrounding area in Assam, India, were simulated using MIKE FLOOD, a coupled 1D-2D hydrodynamic model. MIKE FLOOD is a platform that integrates the MIKE Hydro River (1D) and MIKE 21 FM (2D) models into a dynamically coupled single modeling framework. The study employed daily discharge and water level data from several gauging stations operated by the Centre Water Commission (CWC), Global Flood Monitoring System (GFMS), and Water Resource Department (WRD) of Assam. First, the MIKE Hydro River (1D) model was calibrated using discharge and water level data from 2016 to 2018 and validated for the period of 2019-2021. The MIKE Hydro River (1D) model's calibration and validation results were evaluated using a numerous of performance metrics. From ALOS PALSAR DEM data / SRTM DEM data, a fine mesh and bathymetry of Majuli Island with a spatial resolution of 10m has been created and provided as an input to the MIKE 21 FM (2D, Flow Model). The MIKE Hydro River (1D) and MIKE 21 FM (2D) models were then linked to the MIKE FLOOD model for simulating two-dimensional flood inundations in the study area through lateral linkages. Flood inundation has been simulated for the year 2020, and the model's maximum flood inundation extent has been compared to the actual flooded area retrieved from Sentinel-1 C-Band satellite data. The R〈sup〉2〈/sup〉 in the study area was ranging between 0.86 and 0.97, but the WBL in the MIKE Hydro River model was less than 1.23. On the opposite hand, the MIKE FLOOD's total accuracy is 93.6 percent according to the confusion matrix. According to the most recent model simulation, flooding will occur between July 19 and July 21, 2020, with the greatest and lowest flood depths being 2.38 and 0.786 m, respectively〈/em〉〈em〉. In addition, the MIKE FLOOD model may be used for flood control in the future, and this research will aid policymakers in the field of water management in achieving successful mitigation measures.〈/em〉〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...