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  • Books  (83,575)
  • Articles  (40,565)
  • 2020-2024  (124,140)
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  • 1
  • 2
    Monograph available for loan
    Monograph available for loan
    Garmisch-Partenkirchen : Institut für atmosphärische Umweltforschung der Fraunhofer- Gesellschaft
    Call number: MOP 44829 / Mitte
    Type of Medium: Monograph available for loan
    Pages: 25 S. , graph. Darst.
    Language: English
    Location: MOP - must be ordered
    Branch Library: GFZ Library
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  • 3
    Monograph available for loan
    Monograph available for loan
    London : Penguin Books
    Type of Medium: Monograph available for loan
    ISBN: 9780141985206
    Language: English
    Branch Library: RIFS Library
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  • 4
    Call number: AWI G6-19-92375
    In: Berichte / Christian-Albrechts-Universität zu Kiel, Institut für Geowissenschaften, Nr. 9
    Type of Medium: Monograph available for loan
    Pages: 278 Seiten , Illustrationen
    ISSN: 0175-9302
    Series Statement: Berichte / Christian-Albrechts-Universität zu Kiel, Institut für Geowissenschaften 9
    Language: German
    Note: Zugleich: Dissertation, Christian-Albrechts-Universität zu Kiel, 1999 , INHALTSVERZEICHNIS 1. Einleitung 1.1 Kenntnisstand und offene Fragen 1.2 Fragestellung und Ziele dieser Arbeit 2. Umweltbedingungen in den Arbeitsgebieten 2.1 Hydrographie, Eisverhältnisse und NAO 2.2 Zur Variation von Wassertiefe und Breite der Dänemarkstraße und zur Vereisung Islands während des letzten Glazials 3. Methoden 3.1 Auswahl der Kernstationen 3.2 Probennahme und Analysen (Übersicht) 3.3 Zur Rekonstruktion von Paläobedingungen im Oberflächenwasser Zur Aussage stabiler Isotopenverhältnisse in planktischen Foraminiferen Zur Messung stabiler Isotopenverhältnisse Zur Massenspektrometrie Zur Rekonstruktion von Oberflächentemperaturen Alkane und Alkohole als Maß für Staubeintrag Eistranspmtiertes Material und vulkanische Aschen 3.4 Zur Rekonstruktion von Paläobedingungen im Zwischen-/ Tiefenwasser Häufigkeit von Cibicides- und anderen benthischen Arten (inkl. Taxonomie) Stabile Isotopenverhältnisse in benthischen Foraminiferen 3.5 AMS 14C-Datierungen Probenreinigung 3. 6 Hauptelementanalysen von vulkanischen Asche-Leithorizonten 3. 7 Geomagnetische Meßgrößen und magnetische Suszeptibiltät 3.8 Techniken zur Spektralanalyse 4. Methodische Ergebnisse 4.1 Zum Einfluß der Probenreinigung auf δ18O-/ δ13C-Werte 4.2 Probleme bei der langfristigen Reproduzierbarkeit von δ18O-Zeitreihen 4.3 Einfluß der Korngröße und Artendefinition planktischer Foraminiferen auf SST-Rekonstruktionen in hohen Breiten 4.4 Vergleich der stabilen Isotopenwerte von Cibicides lobatulus und Cibicidoides wuellerstorfi 5. Stratigraphische Grundlagen und Tiefenprofile der Klimasignale 5.1 Stratigraphische Korrelation zwischen parallel-gekernten GKG- und SL-/KL-Profilen 5.2 Flanktische δ18O-/ δ13C-Kurven, 14C-Alter und biostratigraphische Fixpunkte Westliches Islandbecken Kern PS2644 Kern PS2646 Kern PS2647 Kern 23351 Vøring-Plateau Kern 23071 Kern 23074 5.3 Benthische δ18O-/ δ13C-Werte in Kern PS2644 5.4 Siliziklastische Sedimentkomponenten: Eistransportiertes Material Westliches Islandbecken Kern PS2644 Kern PS2646 Kern PS2647 Vøring-Plateau Kern 23071 Kern 23074 5.5 Vulkanische Glasscherben in Kern PS2644: Wind- und Eiseintrag 5.6 Geochemie und Alter einzelner Tephralagen als Leithorizonte Westliches Islandbecken Kern PS2644 Kern PS2646 Kern PS2647 Vøring-Plateau Kern 23071 Kern 23074 5.7 Magnetische Suszeptibilität in den Kernen PS2644, PS2646 und PS2647 Kern PS2644 Kern PS2646 und PS2647 5.8 Geomagnetische Feldintensität und Richtungsänderungen in Kern PS2644 5.9 Variation von Planktonfauna und -flora Westliches Islandbecken: Kern PS2644 Kern PS2646 und PS2647 Vøring-Plateau: Kern 23071 und 23074 5.10 Benthische Foraminiferen in Kern PS2644 6. Entwicklung von Temperatur und Salzgehalt nördlich der Dänemark-Straße 6.1 Variation der Oberflächentemperatur nach Planktonforaminiferen 6.2 Variation der Oberflächentemperatur nach Uk37 6.3 Variation der Oberflächensalinität 7. Die Feinstratigraphie von Kern PS2644 als Basis für eine Eichung der 14C-Altersskala 22 - 55 ka 7.1 Korrelation zwischen den Klimasignalen in Kern PS2644 und der GISP2-Klimakurve zum Kalibrieren der 14C-Alter und Erstellen eines Altersmodells Tephrachronologische Marker Korrelationsparameter und -regeln Sonderfälle/ Probleme bei der Korrelation 7.2 Alters-stratigraphische Korrelation der Klimakurven von Kern 23071 und 23074 7.3 Variation der Altersanomalien zwischen 20 und 55 14C-ka 7.4 Variabilität des planktischen 14C-Reservoiralters in Schmelzwasserbeeinflußten Seegebieten Variation der planktischen 14C-Alter unmittelbar an der Basis von Heinrich-Ereignis 4 Unterschiede zwischen planktischen und benthischen 14C-Altern in der westlichen Islandsee. Zur Erklärung der inversen Altersdifferenzen 7.5 Differenz zwischen 14C- und Kalenderalter: Zeitliche Variation unter Einfluß des Erdmagnetfeldes - Modell und Befund 7.6 Sedimentationsraten der Kerne 23071, 23074 und PS2644 nach dem GISP2-Altersmodell Vøring-Plateau: Kerne 23071 und 23074 Südwest-Islandsee: Kern PS2644 8. Klimaoszillationen im Europäischen Nordmeer in der Zeit und Frequenzdomäne 8.1 "Der Einzelzyklus" in den Klimakurven von Kern PS2644 8.2 Zur Veränderlichkeit der Warm- und Kaltextreme sowie Zyklenlänge Besonderheiten in der Zyklenlänge Variation der Kalt-(Stadiale) Variation der Interstadiale 8.3 Periodizitäten der Klimasignale im Frequenzband der D.-Oe.-Zyklen. Der D.-Oe.-Zyklus von 1470 J., seine Multiplen und harmonischen Schwingungen Weitere Frequenzen: 1000-1150 Jahre- und 490- 510 Jahre-Zyklizitäten Höhere Frequenzen im Bereich von Jahrhunderten und Dekaden 8.4 Phasenbeziehungen und (örtliche) Steuemngsmechanismen der Dansgaard-Oeschger-Zyklen 9. Schlußfolgerungen Danksagung Literaturverzeichnis Anhang
    Location: AWI Reading room
    Branch Library: AWI Library
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  • 5
    Journal available for loan
    Journal available for loan
    München : Altop Verlag ; 2007 -
    Call number: Z 19.92410
    Type of Medium: Journal available for loan
    Pages: 30 cm
    ISSN: 1865-4266
    Former Title: Vorg. Nachhaltiges Wirtschaften in Deutschland
    Language: German
    Note: Ungezählte Beil. ab 2010: Special , Ersch. jährl. 4x
    Branch Library: RIFS Library
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  • 6
    Type of Medium: Monograph available for loan
    Pages: Bände (Loseblattsammlung)
    ISBN: 9783963144509 , 3963144505
    Subsequent Title: Fortsetzung von EnEV und Energieausweise ...
    Language: German
    Branch Library: PIK Library
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  • 7
    Call number: (DE-599)GBV03709842X
    Type of Medium: Monograph available for loan
    Language: German
    Location: MOP - must be ordered
    Branch Library: GFZ Library
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  • 8
    Monograph non-lending collection
    Monograph non-lending collection
    Leiden : Nijhoff ; 1.2009 -
    Call number: IASS 17.92082
    Type of Medium: Monograph non-lending collection
    ISSN: 1876-8814
    Language: English
    Branch Library: RIFS Library
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  • 9
    Monograph available for loan
    Monograph available for loan
    Leningrad : Gidrometeorolog. Izd.
    Call number: MOP 33767
    Type of Medium: Monograph available for loan
    Pages: 663 S.
    Language: Russian
    Note: In kyrill. Schr., russ.
    Location: MOP - must be ordered
    Branch Library: GFZ Library
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  • 10
    Monograph available for loan
    Monograph available for loan
    Stuttgart : Schweizerbart Science Publishers ; Volume 1, number 1 (1978)-
    Call number: M 18.91571
    Type of Medium: Monograph available for loan
    Pages: 134 Seiten
    ISSN: 2363-7196
    Series Statement: Global tectonics and metallogeny : special issue Vol. 10/2-4
    Classification:
    Tectonics
    Parallel Title: Erscheint auch als Global tectonics and metallogeny
    Language: English
    Location: Upper compact magazine
    Branch Library: GFZ Library
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  • 11
    Call number: AWI A3-20-93434
    In: Meteorologische Abhandlungen / Institut für Meteorologie und Geophysik der Freien Universität Berlin, Band XXXII, Heft 1
    Type of Medium: Series available for loan
    Pages: 121 Seiten , Illustrationen
    Series Statement: Meteorologische Abhandlungen / Institut für Meteorologie und Geophysik der Freien Universität Berlin 32,1
    Language: German
    Note: Zugleich: Dissertation, Freie Unversität Berlin, [ca. 1963] , INHALTSVERZEICHNIS PROBLEMSTELLUNG UND ZIELSETZUNG 1. BEMERKUNGEN ZUM BEOBACHTUNGSGELÄNDE UND ZUM BEOBACHTUNGSMATERIAL 1.1 Das Beobachtungsgelände 1.2 Das Beobachtungsmaterial 2. HOMOGENITÄTSBETRACHTUNGEN 2.1 Temperatur 2.2 Niederschlag 2.3 Wind 2.4 Sonnenschein und Bewölkung 3. TEMPERATURVERHÄLTNISSE 3.1 Monats- und Jahreswerte 3.2 Tageswerte 3.3 Pentadenwerte 3.4 Häufigkeitsbetrachtungen 3.5 Interdiurne Veränderlichkeit 3.6 Der tägliche Gang 3.7 Vorkommen bestimmter Schwellenwerte 3.71 Frost- und Eistage 3.72 Sommer- und Tropentage 4. DER WASSERGEHALT DER LUFT 4.1 Monats- und Jahreswerte 4.2 Tageswerte 4.3 Häufigkeitsbetrachtungen 4.4 Interdiurne Veränderlichkeit 4.5 Der tägliche Gang 5. BEWÖLKUNGSVERHÄLTNISSE 5.1 Monats- und Jahreswerte 5.2 Tageswerte 5.3 Häufigkeitsbetrachtungen 5.4 Der tägliche Gang 5.5 Heitere und trübe Tage 5.6 Nebel 6. SONNENSCHEIN 6.1 Monats- und Jahreswerte 6.2 Tageswerte 6.3 Der tägliche Gang 7. NIEDERSCHLAGSVERHÄLTNISSE 7.1 Monats- und Jahreswerte 7.2 Niederschlagsbereitschaft 7.3 Tageswerte 7.4 Der tägliche Gang 7.5 Häufigkeitsbetrachtungen 7.6 Niederschlags- und Trockenperioden 7.7 Niederschlag und Wind· 7.8 Schneeverhältnisse 7.81 Schneefall und Schneedecke 7.82 Schneehöhe 7.9 Gewitter 8. WINDVERHÄLTNISSE 8.1 Windrichtung 8.2 Windgeschwindigkeit 8.21 Der jährliche Gang 8.22 Häufigkeitsbetrachtungen 8.23 Sturmtage und Windstillen 8.24 Der tägliche Gang 9.ZUSAMMENFASSUNG VERZEICHNIS DER TEXTTABELLEN VERZEICHNIS DER ABBILDUNGEN LITERATURVERZEICHNIS TABELLENANHANG
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  • 12
    Journal available for loan
    Journal available for loan
    Tübingen : Mohr Siebeck ; 1.1884 - 48.1931; N.F. 1.1932/33 - 10.1943/44(1945),3; 11.1948/49(1949) -
    Call number: ZS 22.95039
    Type of Medium: Journal available for loan
    Pages: Online-Ressource
    ISSN: 1614-0974 , 0015-2218 , 0015-2218
    Language: German , English
    Note: N.F. entfällt ab 57.2000. - Volltext auch als Teil einer Datenbank verfügbar , Ersch. ab 2000 in engl. Sprache mit dt. Hauptsacht.
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  • 13
    Monograph available for loan
    Monograph available for loan
    Madrid : Secc
    Call number: PIK N 456-17-90913
    Type of Medium: Monograph available for loan
    Pages: 536 Seiten
    Series Statement: Ministerio de Transportes Turismo Y Comunicaciones : Publicación Serie A 114
    Parallel Title: 1,1=6; 2,1=13 von Publicaciones / D / Ministerio del Aire, Subsecretaria de Aviación Civil, Servicio Meteorológico Nacional
    Language: Spanish
    Location: A 18 - must be ordered
    Branch Library: PIK Library
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  • 14
    Call number: S 90.0066(162,1)
    In: Geologisches Jahrbuch / A
    Type of Medium: Series available for loan
    Pages: 261 Seiten , Ill., 1 DVD-ROM (12 cm) und 1 Tafel-Beil. ([2] S.)
    ISBN: 9783510968534
    Series Statement: Geologisches Jahrbuch 162
    Classification:
    Engineering Geophysics
    Language: German
    Location: Lower compact magazine
    Branch Library: GFZ Library
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  • 15
    Call number: PIK N 453-17-91096
    Type of Medium: Monograph available for loan
    Pages: 50 Seiten , Illustrationen, Diagramme
    Language: German
    Location: A 18 - must be ordered
    Branch Library: PIK Library
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  • 16
    Call number: IASS 22.95033
    Type of Medium: Monograph available for loan
    Pages: 378 S , 225 mm x 135 mm
    ISBN: 3899421876 , 978-3-89942-187-3
    Series Statement: Edition panta rei
    Language: German
    Note: Zugl.: Marburg (Lahn), Univ., Habil.-Schr., 2004 u.d.T.: Gutmann, Mathias: Die Medialität des Erfahrens
    Branch Library: RIFS Library
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  • 17
    Monograph available for loan
    Monograph available for loan
    [Edgecumbe, N.Z.] : A. Muller
    Call number: M 15.89146
    Description / Table of Contents: An account of the results of the 2 March 1987 earthquake in the eastern Bay of Plenty and the aftermath's effects on the people and places on the Rangitaiki Plains
    Type of Medium: Monograph available for loan
    Pages: 223 S., , Ill.
    Language: English
    Branch Library: GFZ Library
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  • 18
    Call number: MOP 19538/1d-6d
    Type of Medium: Monograph available for loan
    Pages: 111 S.
    ISSN: 0486-2287
    Language: Russian
    Note: In kyrill. Schr.
    Location: MOP - must be ordered
    Branch Library: GFZ Library
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  • 19
    Call number: Z 06.0500
    Type of Medium: Journal available for loan
    Pages: 30 cm
    ISSN: 1824-7741
    Former Title: Vorgänger Geologisch-paläontologische Mitteilungen, Innsbruck
    Language: German , English
    Note: Ersch. unregelmäßig , Beiträge teilweise in Englisch
    Branch Library: GFZ Library
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  • 20
    Call number: IASS 15.89494
    Type of Medium: Monograph available for loan
    Pages: Losebl.-Ausg.
    Edition: Stand: Oktober 2010
    ISBN: 9783768501828
    Language: German
    Branch Library: RIFS Library
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  • 21
    Call number: 3/S 07.0034(2016)
    In: Annual report
    Type of Medium: Monograph available for loan
    Pages: 51 Seiten
    ISSN: 1865-6439 , 1865-6447
    Parallel Title: Erscheint auch als Annual report ... / Helmholtz Association of German Research Centres
    Language: English
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  • 22
    Call number: AWI A3-20-93434-2
    In: Meteorologische Abhandlungen / Institut für Meteorologie und Geophysik der Freien Universität Berlin, Band XXXII, Heft 2
    Type of Medium: Series available for loan
    Pages: 218 Seiten , Illustrationen
    Series Statement: Meteorologische Abhandlungen / Institut für Meteorologie und Geophysik der Freien Universität Berlin 32,2
    Language: German
    Note: Zugleich: Dissertation, Freie Unversität Berlin, [ca. 1963] , INHALTSVERZEICHNIS PROBLEMSTELLUNG UND ZIELSETZUNG 1. BEMERKUNGEN ZUM BEOBACHTUNGSGELÄNDE UND ZUM BEOBACHTUNGSMATERIAL 1.1 Das Beobachtungsgelände 1.2 Das Beobachtungsmaterial 2. HOMOGENITÄTSBETRACHTUNGEN 2.1 Temperatur 2.2 Niederschlag 2.3 Wind 2.4 Sonnenschein und Bewölkung 3. TEMPERATURVERHÄLTNISSE 3.1 Monats- und Jahreswerte 3.2 Tageswerte 3.3 Pentadenwerte 3.4 Häufigkeitsbetrachtungen 3.5 Interdiurne Veränderlichkeit 3.6 Der tägliche Gang 3.7 Vorkommen bestimmter Schwellenwerte 3.71 Frost- und Eistage 3.72 Sommer- und Tropentage 4. DER WASSERGEHALT DER LUFT 4.1 Monats- und Jahreswerte 4.2 Tageswerte 4.3 Häufigkeitsbetrachtungen 4.4 Interdiurne Veränderlichkeit 4.5 Der tägliche Gang 5. BEWÖLKUNGSVERHÄLTNISSE 5.1 Monats- und Jahreswerte 5.2 Tageswerte 5.3 Häufigkeitsbetrachtungen 5.4 Der tägliche Gang 5.5 Heitere und trübe Tage 5.6 Nebel 6. SONNENSCHEIN 6.1 Monats- und Jahreswerte 6.2 Tageswerte 6.3 Der tägliche Gang 7. NIEDERSCHLAGSVERHÄLTNISSE 7.1 Monats- und Jahreswerte 7.2 Niederschlagsbereitschaft 7.3 Tageswerte 7.4 Der tägliche Gang 7.5 Häufigkeitsbetrachtungen 7.6 Niederschlags- und Trockenperioden 7.7 Niederschlag und Wind· 7.8 Schneeverhältnisse 7.81 Schneefall und Schneedecke 7.82 Schneehöhe 7.9 Gewitter 8. WINDVERHÄLTNISSE 8.1 Windrichtung 8.2 Windgeschwindigkeit 8.21 Der jährliche Gang 8.22 Häufigkeitsbetrachtungen 8.23 Sturmtage und Windstillen 8.24 Der tägliche Gang 9.ZUSAMMENFASSUNG VERZEICHNIS DER TEXTTABELLEN VERZEICHNIS DER ABBILDUNGEN LITERATURVERZEICHNIS TABELLENANHANG
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  • 23
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physics Letters B 294 (1992), S. 466-478 
    ISSN: 0370-2693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 24
    Electronic Resource
    Electronic Resource
    Amsterdam : Elsevier
    Physics Letters B 317 (1993), S. 474-484 
    ISSN: 0370-2693
    Source: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002
    Topics: Physics
    Type of Medium: Electronic Resource
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  • 25
    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
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  • 26
    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
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  • 27
    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.
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  • 28
    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.
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  • 29
    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.
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  • 30
    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.
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  • 31
    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.
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  • 32
    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.
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  • 33
    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.
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  • 34
    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
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  • 35
    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
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  • 36
    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
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  • 37
    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.
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  • 38
    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.
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  • 39
    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.
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  • 40
    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.
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  • 41
    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.
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  • 42
    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.
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  • 43
    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.
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  • 44
    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.
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  • 45
    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.
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  • 46
    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
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  • 47
    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
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  • 48
    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
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  • 49
    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
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  • 50
    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〉
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  • 51
    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〉
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  • 52
    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〉
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  • 53
    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〉
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  • 54
    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〉
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  • 55
    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〉
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  • 56
    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〉
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  • 57
    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〉
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  • 58
    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〉
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  • 59
    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〉
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  • 60
    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〉
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  • 61
    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〉
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  • 62
    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〉
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  • 63
    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〉
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  • 64
    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〉
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  • 65
    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〉
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  • 66
    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〉
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  • 67
    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〉
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  • 68
    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〉
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  • 69
    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〉
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  • 70
    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〉
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  • 71
    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〉
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  • 72
    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〉
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  • 73
    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〉
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  • 74
    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〉
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  • 75
    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〉
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  • 76
    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〉
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  • 77
    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〉
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  • 78
    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〉
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  • 79
    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〉
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  • 80
    Publication Date: 2024
    Description: 〈p〉Drought is a major natural extreme event that can cause significant damage to water 〈br〉resources. This study investigated the implications of drought for Watersheds in Euphrates 〈br〉River basin in Iraq which includes Hilla, Karbala, Najaf, Diwaniyah, and Najaf.. It was 〈br〉found that had an adverse impact on the study region. Among the most often used drought 〈br〉assessment indices globally are the Standard Precipitation Index (SPI) and its version, the 〈br〉Standard Precipitation and Evapotranspiration Index (SPEI). The study evaluated several 〈br〉probability distribution functions to model rainfall and water balance in Iraq. The 〈br〉Kolmogorov–Smirnov (K–S) test and the Anderson–Darling (A–D) test were used to test 〈br〉the goodness-of-fit for rainfall and water balance. The log-normal distribution was found to 〈br〉be the best fit for rainfall at approximately 40% of the stations considered, while the 〈br〉generalized logistic distribution (genlog) was the best fit for water balance at approximately 〈br〉80% of the stations considered. The study also found that the extreme droughts in Samwah 〈br〉in 2012 and Diwiniyah in 1999 had the highest severity values of -2.8957 in SPI-12 and 〈br〉SPEI-12, respectively. 〈/p〉
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  • 81
    Publication Date: 2024
    Description: 〈p〉The use of Remote Sensing data in monitoring water bodies and reservoirs is a new and advanced approach that helps to study large areas covered by water in a short time and at a reasonable amount compared to traditional methods. Accordingly, the Remote Sensing technique integrated with Geographic Information Systems (GIS) has been used in several studies to monitor changes in water surface body area locally and regionally. In this study, several studies in Iraq were reviewed, using Remote Sensing techniques with the help of GIS to detect changes in the areas covered by the water bodies using satellite images captured in different periods. Natural and artificial lakes represent a large proportion of the water bodies in Iraq, including eight (8) lakes distributed in different regions of Iraq. An evaluation of the hydrological system of the studied water bodies showed that the changes in the area and size of natural and artificial lakes are affected by political, economic, and climatic conditions as the areas increase and decrease over years. 〈/p〉
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  • 82
    Publication Date: 2024
    Description: 〈p〉Biostratigraphy of the Sinjar Formation is investigated in two sections (Dokan and Sinjar)〈br〉from northeastern and northwestern Iraq, respectively. Two hundred samples from all the〈br〉limestones and marl that form the main lithological components of the studied sections were〈br〉collected. The studied limestones and marl are rich in microfossils. Through thin sections, we〈br〉were able to identify thirty species of benthic foraminifera and fifteen species of other〈br〉microfossils (coral, algae, mollusca, bryozoa, and echinoids) at Dokan section, and fifty-one〈br〉species of benthic foraminifera and thirty species of other microfossils at Sinjar section. 3〈br〉biozones were distinguished from both sections 1-Biozone A: Kathina sp.- Lockhartia hunti〈br〉Assemblage zone (SBZ 5) (Dokan section); (Kathina pemavuti - Lockhartia hunti Assemblage〈br〉zone (Sinjar section), 2- Biozone B: Idalina sinjarica Total Range zone (SBZ 6-7) and 3-〈br〉Biozone C: Alveolina globosa- Alveolina pasitisilata Concurrent Range Zone (SBZ8-10).〈br〉These zones indicate the Late Paleocene –Early Eocene age of the Sinjar formation. The〈br〉biostratigraphic correlations in the studied sections are based on benthic foraminiferal〈br〉zonations. Showed the correlation comparison between the biostratigraphic zones of the〈br〉commonly used benthic zonal scheme around the Late Paleocene -Early Eocene in and outside〈br〉of Iraq. paleoecological studies suggest that the carbonate sedimentation of the Sinjar〈br〉Formation thrived in 18-25oC, with mesophotic to oligophobic light, under an oligotrophic to〈br〉mesotrophic middle ramp environment with normal marine to slightly saline and at water〈br〉depths from 40 - 80 m. Stable isotopic carbon (δ13C) and oxygen (δ18O) data revealed generally〈br〉hot conditions with high productivity during the deposition of the Sinjar Formation〈br〉accompanied by an abrupt change in paleoenvironmental conditions across the Paleocene-〈br〉Eocene contact.〈/p〉
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  • 83
    Publication Date: 2024
    Description: 〈p〉Wellbore instability is one of the most common issues encountered during drilling 〈br〉operations. This problem becomes enormous when drilling deep wells that are passing 〈br〉through many different formations. The purpose of this study is to evaluate wellbore failure 〈br〉criteria by constructing a one-dimensional mechanical earth model (1D-MEM) that will help 〈br〉to predict a safe mud-weight window for deep wells. An integrated log measurement has 〈br〉been used to compute MEM components for nine formations along the studied well. 〈br〉Repeated formation pressure and laboratory core testing are used to validate the calculated 〈br〉results. The prediction of mud weight along the nine studied formations shows that for 〈br〉Ahmadi, Nahr Umr, Shuaiba, and Zubair formations ranges between 12.5 to 15 ppg. The 〈br〉predicted safe mud weight value seems to be narrow with a well deviation higher than 350. 〈br〉Therefore, for Ahmadi, Nahr Umr, Shuaiba, and Zubair formations, the wellbore 〈br〉appears unstable compared to other formations. The results of stability analyses indicate that 〈br〉the breakout mud weight wasn’t affected by wellbore azimuth because of low-stress 〈br〉contrast. Furthermore, shear failure can be prevented by drilling the well with an inclination 〈br〉of less than 350. As well as, to prevent breakdown the well should be drilled with an 〈br〉inclination between 25o to 65o in the direction of minimum horizontal stress. These 〈br〉outcomes could be used to prevent wellbore instability and determine a safe mud-weight 〈br〉window when planning to drill nearby wells in the future. 〈/p〉
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  • 84
    Publication Date: 2024
    Description: 〈p〉This study aims to diagnose microfacies of the Jeribe Formation to determine depositional environments and derivation depositional model for this formation. The study consisted of two wells in the Hamrin anticline north of the Saladin Governorate within the foothill zone. In the study area, the lower contact of the Jeribe Formation is unconformable with the Dhiban Formation, whereas the upper contact is conformable with the Fatha Formation. Depending on the microfacies analysis, four significant microfacies were distinguished, including mudstone, wackestone, packstone, and grainstone, and then divided into eight submicrofacies types depending on grain types. The microfacies analysis of the Jeribe Formation revealed the recognition of five environments: open-marine (middle ramp to inner ramp), restricted, shoal, lagoon, and partial environments. The majority of microfacies are determined within the inner ramp setting. The Jeribe Formation was deposited in a shallow marine environment. 〈/p〉
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  • 85
    Publication Date: 2024
    Description: 〈p〉The research strives to enhance digital surveying methodologies for precise and detailed land mapping, utilizing advanced instruments like terrestrial scanners, SLAM scanners, total stations, DGPS, and drones. The survey conducted at Ratnagiri Hill in Udaipur aims to scrutinize and compare the merits and drawbacks of each surveying method. The study outlines a systematic process encompassing data collection, processing, output generation, and validation of survey techniques. It highlights the adaptability of these methods across various〈br〉domains, such as building conservation, restoration, and mapping of typically inaccessible areas, emphasizing their potential for time and resource savings. The research underscores the effectiveness of a one-time data collection process for subsequent work, laying the groundwork for the advancement of digital surveying technologies. When integrated with the Total station and DGPS survey, the combination of terrestrial scanners, drones, and SLAM scanners achieves a vertical accuracy of around 32 mm.〈/p〉
    Print ISSN: 2321-421X
    Electronic ISSN: 2230-7990
    Topics: Geography , Geosciences
    Published by STM Journals
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  • 86
    Publication Date: 2024
    Description: Predicting reservoir performance in the future is closely related to the accurate identification of reservoir history in the past. In this study, based on a new approach, risk zonation in hydrocarbon reservoirs has been evaluated using different available data include well production, characteristics of fractures and faults, rock heterogeneity and seismic data, which can be used in the field of reservoir management. The study is carried out on Mishrif formation in Sirri oil fields. The well test results have been used in the period between 1977-1992 and permeability in the drainage area of all production wells have been calculated by applying an empirical relationship between wellhead pressure and permeability. By calculating the permeability in the all production wells the strain values, which represent the compaction parameter, are estimated based on the permeability-strain empirical relationships. Strain value is considered an important parameter for predicting the future oil production rate. In this study, the effect of different parameters on strain distribution such as fault effects, characteristics of reservoir fractures, rock heterogeneity and rock density have been also investigated. Based on the obtained strain results, all existing wells have been classified into three different regions included region A (referred to high rate of volumetric strain) region B (referred to moderate rate of volumetric strain), and region C (referred to low level of volumetric strain) which can be used for the future performance of the wells and also for making accurate decisions regarding to better management of Mishrif formation reservoir in Siri oil field
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  • 87
    Publication Date: 2024
    Description: شناخت نقش فرآیندهای مختلف برای درک گرمایش پلاسما تا میلیون‌ها درجه در ناحیه گذار و تاج خورشید بسیار مهم است. بر این اساس ما به بررسی نمایه‌های طیفی نامتقارن در ناحیه‌گذار خورشید می‌پردازیم. روش شناسایی این عدم‌تقارن‌ها بر اساس برازش الگوهای تک-دو گاوسی است. داده‌های طیفی مورد استفاده در این تحقیق توسط طیف‌نگار تصویربرداری ناحیه رابط (آیریس) در ۱۴ اکتبر ۲۰۱۵ در طول موج ۱۳۹۴ آنگستروم Si‌ IV ثبت شده است. با بررسی بیش از ۱۰۳۰۰۰ طیف ناحیه‌ گذار، با برآورد سه شرط تجربی، ۱۵۹۸ نمایه نامتقارن با عدم تقارن یک سمتی یا دوسمتی یافت شد. در این پژوهش سه شرط تجربی برآورد عدم تقارن در طیف معرفی می‌شود: (۱) مقدار معنا‌داری برازش الگوی تک گاوسی بیشتر از یک، (۲) حداقل شدت دو مولفه (قله اول و دوم در نمایه طیف) بیشتر از DN ۲۰ (تعداد فوتون‌های رسیده در قله نمایه طیف) و (۳) فاصله مراکز دو مولفه طیف در مقیاس سرعت بیشتر از ۲۰ کیلومتر بر ثانیه. بیشترین تعداد نمایه‌های نامتقارن مربوط به نمایه‌ای با یک مولفه در سمت آبی آن است. کمترین تعداد را نمایه‌هایی ناسازگار با هر دو الگوی برازش تک و دو گاوسی (نمایه-هایی با دو بال) در اختیار دارند. ما نشان دادیم که موقعیت نمایه‌های نامتقارن روی نواحی با چگالی بالای شار مغناطیسی در اچ‌ام‌آی (ابزار مغناطیس نگار خورشیدی بر روی رصدخانه دینامیک خورشیدی اس‌دی‌او است) و همچنین نواحی شبه شبکه‌ای روشن در مقیاس بزرگ در تصویر رستر ۱۳۳۰ آنگستروم متمرکز است ، که نشان‌دهنده‌ی ساز‌‌و‌کارهای مغناطیسی در بروز عدم تقارن طیف ناحیه گذار است.
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  • 88
    Publication Date: 2024
    Description: تفکیک بی‌هنجاری‌های ناحیه‌ای و محلی در مطالعات میدان پتانسیل و به خصوص در داده‌های گرانی‌سنجی، پایه و مبنای تفسیر آن‌ها است. نتایج مدل‌سازی معکوس داده‌های میدان پتانسیل به عنوان اصلی‌ترین مرحله تفسیر به شدت تحت تاثیر داده‌های ورودی است که از مرحله تفکیک بی‌هنجاری‌های ناحیه‌ای و محلی به دست می‌آید. تاکنون روش‌های متعددی برای تفکیک بی‌هنجاری ناحیه‌ای از محلی در داده‌های میدان پتانسیل ارائه شده است که هر کدام دارای مزایا و معایبی هستند. اغلب روش‌های تفکیک بی‌هنجاری مبتنی بر تفکیک مولفه‌های عدد موج مربوط به هر کدام از بی‌هنجاری‌های محلی و ناحیه‌ای از یکدیگر می‌باشند. مطالعات پیشین نشان داده است که میان دامنه مولفه‌های عدد موج در طیف دامنه دو بعدی و مقادیر تکین ماتریس مسیر به دست آمده از داده میدان پتانسیل ارتباط مستقیم و نظیر به نظیر وجود دارد. بنابراین، می‌توان بی‌هنجاری‌های ناحیه‌ای و محلی در داده‌های گرانی‌سنجی را با استفاده از روش تجزیه ماتریس مسیر داده گرانی به مولفه رتبه – پایین یا روش کاهش رتبه ماتریس مسیر تفکیک کرد. در این مقاله، الگوریتم تحلیل طیفی تکینی برای کاهش رتبه ماتریس مسیر داده گرانی به منظور تفکیک بی‌هنجاری‌های ناحیه‌ای و محلی در داده‌های مدل مصنوعی و واقعی استفاده شد و نتایج آن با روش‌های تفکیک فیلتر داده‌مبنا، برازش چندجمله‌ای و ادامه فراسو مقایسه گردید. نتایج به دست آمده در مدل مصنوعی و واقعی نشان داد که روش پیشنهادی نسبت به سایر روش‌‌های مورد مقایسه در این مقاله، دقت بیشتری در تفکیک بی‌هنجاری‌های ناحیه‌ای و محلی دارد و اثرات کاذب کمتری در نتیجه حاصل ایجاد می‌کند.
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  • 89
    Publication Date: 2024
    Description: نیاز روز افزون صنایع فولاد سازی به کانه آهن و کاهش عیار و تناژ معادن فعال بزرگ موجود، انگیزه اکتشاف کانسارهای آهن کوچک مقیاس و یا پنهان را افزایش داده است. پژوهش حاضر به پی جویی یکی از این کانسار در واقع در استان یزد پرداخته است. در این راستا، قدم اول انجام دورسنجی با تولید ترکیب های رنگی کاذب و نسبت‌های باندی تصاویر ماهواره استر و لندست 8 بود. این روشها حضور اکسید‌های آهن فرو و فریک و دگرسانی‌های محل کانسار آهن مرور را آشکار ساختند. همچنین محاسبه سیگنال تحلیلی داده های مغناطیسی محدوده، مرزهای بی‌هنجاری‌های مغناطیسی را مشخص نمود. این مراحل نشان داد که همبستگی فضایی معناداری بین اکسید آهن فرو و بی هنجاریهای مغناطیسی وجود دارد. افزون بر این، نتایج روشهای واهمامیخت اویلر و طیف توان نشان داد که منابع مغناطیسی در عمق حدود 65 متر واقع شده اند. بعدا از عمق تخمین زده شده برای تعریف وزن دهی عمقی در یک وارون سازی سه بعدی داده‌های مغناطیسی استفاده شد. این وارون سازی، مدلی سه بعدی از شکل توزیع خودپذیری مغناطیسی در عمق را ارائه کرد. بر اساس مدل تخمین زده شده، مناطق دارای بزرگترین خودپذیری مغناطیسی با محلهای عیاربالای آهن در طول چاه های اکتشافی مطابقت دارند. این مقایسه همچنین نشان داد که زون‌های با خودپذیری مغناطیسی بالا غالبا در عمق 50 تا 100 متری قرار گرفته اند.
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  • 90
    Publication Date: 2024
    Description: در این مطالعه یک رویداد بارش همرفتی، با استفاده از طرحواره‌ی خردفیزیکی حساس به هواویز در مدل WRF مورد بررسی قرار گرفت. دو شبیه‌سازی کنترلی و آلوده انجام شد. اختلاف بازتاب تابش خورشیدی به فضا توسط ابرها در آزمایش آلوده افزایش می‌یابد که نشان می‌دهد اولین اثر غیرمستقیم هواویزها نقش عمده‌ای در بودجه انرژی جوّ ایفا می‌کند. تأثیر غلظت هواویزها بر توسعه ابر در این شبیه‌سازی که دارای همگرایی بیشتر شار قائم رطوبت و سرعت‌های باد بیشتر در منطقه مورد مطالعه است، قابل‌توجه است. باتوجه به همگرایی شار قائم رطوبت، بخارآب بیشتری برای میعان کردن روی ذرات هواویز وجود دارد و منجر به افزایش محتوای آب ابر می شود. چگالی عددی قطرک ابر در آزمایش آلوده در مقایسه با آزمایش کنترلی بیشتر است. افزایش مقدار یخ و برف که نشان‌دهنده بلند شدن بیشتر قطرات آب تا سطح انجماد است، می‌تواند به‌دلیل همگرایی شار قائم رطوبت منفی باشد وکاهش محتوای آب ابر به دلیل واگرایی رطوبت در این مناطق رخ داده است. اختلاف میزان بارش در دو آزمایش آلوده و کنترلی در بیشتر نقاط حوزه مقادیر مثبت را نشان می‌دهد که به این دلیل است که در جوّ مرطوب بخار آب به اندازه کافی برای میعان روی ذرات هواویز وجود دارد که موجب تشکیل قطرک های بزرگتر ابر می‌شود. در نتیجه، قطرک‌های ابر برخوردهای مؤثرتری دارند و بارش افزایش می‌یابد.
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  • 91
    Publication Date: 2024
    Description: تندبادهای شدید با سازوکار فروپُکشی که معمولاً با گرد و خاک همراه هستند در برخی کشورها با نام هبوب شناخته می‌شوند. در دهه اخیر برخی از توفا‌ن‌های اتفاق‌افتاده در شهر تهران که خسارات متعددی به وجود آورده شامل سازوکار رخداد هبوب بوده‌اند. در این مطالعه روشی برای امکان‌سنجی پیش‌بینی پتانسیل رخداد توفان‌های با ساختار فروپُکشی معرفی شد که سطوح تعریف شده هشدار برای این پدیده را ارائه می‌دهد. در کار حاضر مدل WRF به صورت یک سامانه همادی در چهار حوزه تودرتو با تفکیک‌های افقی مختلف به‌کار گرفته شده است. پنج شاخص ترمودینامیکی مختلف برای نقاط شبکه محاسبه شد و فرایند محاسبه پتانسیل رخداد تندباد با ساختار فروپُکشی با در نظرگرفتن شرایط دمایی در سطح زمین، شرایط ترمودینامیکی جو، نمایه قائم رطوبت نسبی و همچنین بررسی وجود شرایط دینامیکی برای صعود هوا انجام گرفت. با ترکیب این شرایط برای برونداد مدل عددی در همه گام‌های زمانی، سه سطح هشدار برای پتانسیل رخداد توفان با سازوکار فروپُکشی به‌صورت پهنه‌بندی رنگ‌های زرد، نارنجی و قرمز ارائه شد. چهار مورد رخداد تندباد و توفان از جمله توفان معروف رخ‌داده در دوم ژوئن 2014 (دوازدهم خردادماه 1393) برای شهر تهران مطالعه شد. مطابق اطلاعات سازمان هواشناسی در این تاریخ‌ها در ایستگاه‌های هواشناسی شهر تهران بادهایی با حداکثر سرعت بین 80 تا 120 کیلومتربرساعت ثبت شده است. در تمامی این موارد مقدار سرعت باد ثبت‌شده به اندازه قابل ملاحظه‌ای بیشتر از پیش‌بینی مستقیم مدل-های پیش‌بینی عددی هواشناسی هستند و در واقع توسط خروجی این مدل‌ها قابل تشخیص و پیش‌بینی نبوده است.
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  • 92
    Publication Date: 2024
    Description: در این تحقیق داده­های ERA5 در برآورد دو دسته پارامتر همرفتی شامل شاخص بالابری (Lifted Index, LI) و چینش قائم بردار باد در سه لایه (Vertical Wind Shear, WVSH) در ایستگاه­های جوّ بالا در ایران در بازه 1990-2020 به کمک شاخص­های آماری ارزیابی شد. در مقیاس ماهانه، کمینه (بیشینه) مقدار RMSE برای VWSH-1000، VWSH-3000 و VWSH-6000 به­ترتیب حدود 3 (5/8)، 36/3 (84/9) و 4 (20) متر بر ثانیه بود. داده­های بازتحلیل مقدار VWSH-1000 را در تمامی ایستگاه­ها (به­جز ایستگاه اهواز) فروبرآورد کرد. برآورد پارامترهای VWSH-3000 و VWSH-6000 با فرابرآورد/فروبرآورد در ماه­های مختلف در ایستگاه­ها همراه بود. در اغلب ایستگاه­ها بیشترین (کمترین) خطا در ماه­های سرد (گرم) رخ داد. روند تغییرات هر سه پارامتر VWSH نشان داد که با افزایش ارتفاع لایه، عملکرد ERA5 در برآورد پارامتر چینش در ایستگاه­ها به­ویژه در سال­های اخیر بهبود یافته است. داده­های بازتحلیل شاخص LI را با بیشترین (کمترین) خطا در ماه­های گرم (سرد) سال تولید کرد. در کل بازه مورد مطالعه برای هر ایستگاه، داده­های بازتحلیل حداقل 10  کلوین (در ایستگاه زاهدان) و حداکثر 15  کلوین (در ایستگاه تهران) در برآورد LI خطا داشت. به غیر از ایستگاه اهواز، در تمامی ایستگاه­ها LI  فروبرآورد شد. میانگین ماهانه LI بازتحلیل بیشتر حاوی شرایط ناپایدار بود در حالی­که مقادیر مشاهداتی بر پایدار بودن جوّ دلالت داشت. با این­حال در ایستگاه­های مشهد و تهران میان روند مقادیر میانگین سالانه بازتحلیل و مشاهداتی همخوانی وجود داشت، درحالیکه در سایر ایستگاه­ها این همخوانی در سال­های آخر به وضوح دیده شد. 
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  • 93
    Publication Date: 2024
    Description: در این مقاله، اقلیم‌شناختی مسیرهای توفان فراحاره‌ایِ نیمکره شمالی و ورودی‌های اصلی توفان‌ها‌ به شمالگان و اثرات احتمالی آن‌ها بر کاهش محلی یخ دریای شمالگان در چهار فصل بررسی شده است. شناسایی مسیرهای توفان با به‌کارگیری روش ردیابی بر تاوایی نسبی و مؤلفه نصف‌النهاری مثبت باد در تراز 850 هکتوپاسکالی از داده‌های ERA5 برای دوره 1979 تا 2023 انجام شده است. از نظر فصلی، مسیرهای توفان در زمستان قوی‌تر و در تابستان ضعیف‌تر هستند. علاوه بر غرب اقیانوس اطلس و آرامِ شمالی به‌عنوان مناطق اصلی زایش توفان‌های اقیانوسی، مرکز اقیانوس آرام شمالی به‌عنوان منطقه ثانویه زایش توفان‌های اقیانوسی به‌ویژه در زمستان محسوب می‌شود و بیشتر توفان‌ها در غرب آمریکای شمالی و غرب گرینلند به بیشینه زدایش می‌رسند. برخی از توفان‌های شکل گرفته در شرق فلات تبت، تا ساحل شرقی آسیا و برخی دیگر تا دریای برینگ نفوذ می‌کنند. کشیدگی محسوس مسیر توفان اطلس از غرب اقیانوس اطلس به سمت شمالگان از طریق دریای گرینلند و دریای نروژ و وجود مقادیر بزرگ زدایش توفان‌ها در این دو دریا، نشان‌دهنده نفوذ توفان - رانده هوای گرم و مرطوب از اقیانوس اطلس به شمالگان است. همچنین چگالی زدایش توفان‌ها در دریای برینگ با ردیابی مؤلفه نصف‌النهاری مثبت باد، افزایش محسوسی می‌یابد که به معنای آن است که توفان‌های نفود کرده تا دریای/تنگه برینگ سبب ورود گرما و رطوبت اقیانوس آرام شمالی به شمالگان می‌شوند. این نفوذ توفان - رانده هوای گرم و مرطوب منجر به کاهش محلی یخ دریا یا کاهش سرعت تولید یخ دریایی به‌ویژه در فصل زمستان می‌شود.
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  • 94
    Publication Date: 2024
    Description: محدوده مورد مطالعه در شمال‌غرب شهرستان سبزوار و در غرب «افیولیت سبزوار» واقع شده است. این منطقه، بواسطه وجود معادن کُرومیت، مشهور می‌باشد. یکی از مراحل بسیار مهم در اکتشاف معادن، شناسایی ساختارهای زمین‌شناسی است. در سنگ‌های پریدوتیتی، شناسایی گسل‌ها، در سطوح طبیعی زمین، بدلیل کم‌یافت بودن لایه‌های کلیدی، معمولا مشکل می‌باشد. سونداژزنی مقاومت‌ویژه الکتریکی با استفاده از آرایه مربعی به روش آزیموتی به عنوان یک رهیافت ژئوفیزیکی برای شناسایی شکستگی‌ها و مشخص کردن جهت آن‌ها در سنگ‌های گسل‌خورده و درزه‌دار بکار می‌رود. بررسی‌های زمین‌شناسی در محدوده مورد مطالعه نشان می‌دهد که زون‌های شکسته و نیز جهت غالب درزه‌ها و شکستگی‌ها ارتباط مستقیمی با محل کانی‌زایی و جهت‌یافتگی ماده معدنی دارد. از اینرو در این تحقیق، برای شناسایی ساختار زمین-شناسی بخشی از محدوده معدنی با تمرکز بر روی شناسایی امتداد غالب شکستگی‌ها، در یک نقطه، روش سونداژزنی مقاومت‌ویژه الکتریکی با استفاده از آرایه مربعی بکار گرفته شده است. سنگ بستر محدوده مورد مطالعه از پریدوتیت‌های سرپانتینی شده تشکیل شده است. داده‌برداری در سرپانتینیت‌های بدون روباره با استفاده از اندازه‌گیری‌های آرایه مربعی، برای بررسی وجود زون گسلی احتمالی، در یکی از معادن انجام شد. مقاومت‌های‌ویژه ظاهری اندازه‌گیری شده به این روش تغییرات قابل ملاحظه‌ای، در جهت‌های مختلف جغرافیایی، نشان داد. تفسیر نتایج بدست آمده از آرایه مربعی نشان می‌دهد که وجود گسل در محدوده مطالعه شده محتمل نبوده و شبکه درزه‌ها، اصلی‌ترین عوارض ساختمانی حاکم در این محدوده است. شکل نمودار‌های مقاومت‌ویژه ظاهری آرایه مربعی، وجود شبکه درزه‌ها را که در چند جهت متفاوت امتداد دارد، تایید می‌کند.
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  • 95
    Publication Date: 2024
    Description: The present study attempts to map the thermal structures of part of the Gongola Basin, NE Nigeria, from airborne magnetic and gamma-ray spectrometry data, with implications for geothermal resource exploration. The residual of the TMI was subdivided into nine spectral overlapping blocks and subjected to spectral analysis to deduce the geothermal parameters, Curie point depth (CPD), geothermal gradient, and heat flow (HF). Likewise, the varying concentrations of radioelements (K, eTh and eU) within the study area were used to estimate the radiogenic heat production (RHP). The results show that the CPD, geothermal gradient, and HF range from 17.31–46.02 km, 12.60–33.51 oCkm-1, and 31.63–84.10 mWm-2, respectively. On the other hand, the radiogenic heat production (RHP) of K, eU, and eTh ranges from 0.00–0.01 µWm-3 〈 0.3–4.2 µWm-3 〈 0.4–7.4 µWm-3. While the total RHP ranges from 0.7 to 7.5 µWm-3. The high RHP obtained in the northwest, west, and southwest flanks of the study area might be a result of the dominant crystalline rocks, while the high RHP observed in the southern part might be attributable to the Pindiga Formation, composed of shale, limestone, and sandstone, which is highly rich in uranium. The regions (central, northwest, southwest, and southeast) with HF 〉 80 mWm-2 and RHPs of 2.5 µWm-3 and above meet the recommended values for good geothermal resources and could be considered good indicators for geothermal energy exploration in the study area.
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  • 96
    Publication Date: 2024
    Description: This research introduces the Pasqale rock/debris avalanche, an occurrence of a prehistoric landslide in the upstream region of Darband Valley in northern Tehran metropolitan that is exemplified as an instance of a high-risk geohazard encountered in the proximity of a metropolitan area. Its initiation as a slide from a steep scarp, with an elevation of approximately 3000 m, nestled within Eocene volcanic rocks and tuff, is noted. The local geology and geomorphology of the Pasqale landslide are described in this paper, relying on topographical data, satellite imagery, and field observations. Through various considerations and the utilization of high-resolution satellite data, the total volume of the landslide is estimated to be in the range of 800,000 m3. Remarkably, the occurrence of this landslide is found to be influenced by intense fracturing and hydrothermal alterations of the Eocene pyroclastic rocks. Moreover, the seismic aspect of the region is emphasized, with particular attention given to the likelihood of a large earthquake being the most probable triggering factor for the Pasqale avalanche, originating from the Mosha or North Tehran faults. The significance of the cascading hazards that may be brought about following a major earthquake event in the northern Tehran metropolitan area is featured in this paper.
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  • 97
    Publication Date: 2024
    Description: 〈p〉This research aimed to determine the optimal locations for artificial groundwater recharge in the central Azraq Basin using geophysical methods and geographic information sciences. The study identified the eight most important criteria affecting the selection of artificial groundwater recharge sites in the area. Using the Analytic Hierarchy Process (AHP) method, the study determined the weight of each criterion and established ratings based on available literature. GIS with Multiple Criteria Decision Analysis (MCDA) were used to select the most suitable sites for groundwater recharge, revealing that 5.7% of the study area has low suitability for groundwater recharge, 39.5% showed moderate, 46% showed high, while the remaining 8.8% of the study area showed very high suitability of groundwater recharge. The study employed the Electrical Resistivity Tomography (ERT) geophysical survey method to verify the results. The ERT results showed that the groundwater level depth in the six examined sites was close to the subsurface level and ranged from 5m at ERT-2 (Basalt aquifer) to larger than 22m in ERT-4 (Rijam aquifer B4), indicating that these sites were suitable for groundwater recharge. ERT results also showed the presence of faulted layers and reveal the presence of favourable recharge zone. Overall, the study recommended that the area can be recognized as having a high potential for groundwater recharge, and projects should be developed accordingly. The research findings have important implications for managing and conserving water resources in arid regions. The study highlights the usefulness of geophysical methods and GIS in identifying and assessing suitable locations for artificial groundwater recharge. It also showed the importance of considering multiple criteria and using a structured decision-making approach in complex decision-making problems. 〈/p〉
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  • 98
    Publication Date: 2024
    Description: 〈p〉The application of remote sensing techniques in geological investigation are used to determine the prospected area of gypsum rocks in the Qara Darbandi Anticline, Kurdistan Region of Iraq. This study aimed to assess the effectiveness of Spectral Angle Mapper (SAM) supervised classification in mapping gypsum rocks applying Landsat Imagery. Rapid-Eye and Landsat multispectral satellite images are used. Image enhancement techniques such as Minimum Noise Fraction (PCA) and Principal Component Analysis (PCA) were employed to perform image transformation methods. The spectral data was collected using an Analytical Spectral Devices (ASD) field spectrometer, and the spectra of gypsum rocks were utilized as the training area zone for the classification of SAM. SAM output map displays the best indication of the gypsum rocks distribution in the southwestern part of Qara Darbandi anticline. Results showed that the FCC (R:3; G:4; B:1); MNF (R:1; G:2; B:3 and R:4; G:3; B:2) and PCA (R:3, G:1, B:2) are the best compositions to determine the outcrop of the Gypsum rocks within the selected area. These findings show the capability of spectral bands of the Rapid-Eye sensors, and Landsat imagery, in addition to the capability of the image processing methods to detect and map the exposed Gypsum rocks. In conclusion, the findings of this study are supported by the fieldwork conducted, the analysis of geochemistry data, and the examination of available geological maps.〈/p〉
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  • 99
    Publication Date: 2024
    Description: 〈p〉Shale was initially regarded mainly as a source rock, but it is now recognized as both a source and reservoir. This shift has led to increased investigation into its geological properties. Extracting oil and gas from low-permeability shale formations is made possible by horizontal drilling, maximizing wellbore-rock contact, and hydraulic fracturing, which enhances permeability. The identification of sweet spot involves considering factors like source rock richness, natural fractures, core analysis, well-log data, and gas data to strategically position wellbores for optimal productivity. This paper aims to locate the sweet spot at the Ahnet Shale Gas Field by applying a comprehensive methodology, proving its accuracy in identifying geological and engineering sweet spots. Geological factors included organic matter quantity, maturity, composition, clay type, and reservoir characteristics. Engineering assessment considered rock mechanics and brittleness index, forming a robust evaluation system. Three significant sweet spot zones were pinpointed based on well-logging and geological data. The geochemical analysis emphasized high-quality Silurian shale rich in type II marine organic matter. Fluid characterization through chromatographic analysis and mechanical properties assessment reinforced the methodology's efficacy, aiding optimal shale gas exploration site selection.〈/p〉
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  • 100
    Publication Date: 2024
    Description: 〈p〉The history basin of the Mishrif formation in Southern Iraq was analyzed by building a model of sedimentary basin, which enabled us to know the geological events that occurred during and after the deposition it. Mishrif formation of age (Late Cenomanian - Early Turonian) is considered one of the most important geological formations containing oil in Southern Iraq, so nine wells were chosen from several oil fields to cover the study area: (Zb-114, R-270, WQ-17, Rt-5, Lu-2, Ns-5, Ri-1, No-2, and Hf-5), located between the Eastern lines (582400-749080) and the Northern lines (3534600-3357197). Mathematical models and equations were used to calculate the original thicknesses and sedimentation rates of the Mishrif formation and the formations above it through the Backstripping method. Estimated of the sedimentation rates and erosional thicknesses of the regional unconformities surfaces that located in the stratigraphic column in the study area. While Mishrif formation was characterized a moderate sedimentation rate that ranged between (2-6cm./1000y.), where increase in the Northeast of the study area in wells (Ri-1, No-2, and Hf-5), these rates an indicator to the center of sedimentary basin. The geological burial history curves show three levels of subsidence rates (Fast, moderate, and low), the burial history of the Mishrif formation and the other formations indicated that the sedimentation rates are in a direct relationship with the total subsidence of the basin. Three regional unconformities surfaces were found which the effectiveness of the tectonic movements, it’s had strong effective to the sedimentary basin of the Mishrif formation and other formations, where exposed it to during the Cretaceous and Tertiary periods. These movements had a major impact on shaping the sedimentary character through its influence on the process of advancement and retreat of the sea level, which formed successive depositional cycles, as the top of the Mishrif formation was exposure to uplifting and erosion processes, especially in the Northeast parts, where formed the first regional unconformity surface about (89-90 m.y.) ago.〈/p〉
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