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  • 1
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    Efficiency-House Optimization to Widen the Operation Range of the Double-Suction Centrifugal Pump (2020)
    Hindawi
    Details
    Publication Date: 2020-09-26
    Description: Most pumping machineries have a problem of obtaining a higher efficiency over a wide range of operating conditions. To solve that problem, an optimization strategy has been designed to widen the high-efficiency range of the double-suction centrifugal pump at design (Qd) and nondesign flow conditions. An orthogonal experimental scheme is therefore designed with the impeller hub and shroud angles as the decision variables. Then, the “efficiency-house” theory is introduced to convert the multiple objectives into a single optimization target. A two-layer feedforward artificial neural network (ANN) and the Kriging model were combine based on a hybrid approximate model and solved with swarm intelligence for global best parameters that would maximize the pump efficiency. The pump performance is predicted using three-dimensional Reynolds-averaged Navier–Stokes equations which is validated by the experimental test. With ANN, Kriging, and a hybrid approximate model, an optimization strategy is built to widen the high-efficiency range of the double-suction centrifugal pump at overload conditions by 1.63%, 1.95%, and 4.94% for flow conditions 0.8Qd, 1.0Qd, and 1.2Qd, respectively. A higher fitting accuracy is achieved for the hybrid approximation model compared with the single approximation model. A complete optimization platform based on efficiency-house and the hybrid approximation model is built to optimize the model double-suction centrifugal pump, and the results are satisfactory.
    Print ISSN: 1076-2787
    Electronic ISSN: 1099-0526
    Topics: Computer Science , Mathematics
    Published by Hindawi
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  • 2
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    Physiochemical, Insecticidal, and Antidiabetic Activities of Senna occidentalis Linn Root (2020)
    Hindawi
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    Publication Date: 2020-09-15
    Description: The present study aimed to investigate the physiochemical activities of Senna occidentalis (Linn) roots and phytochemicals as insecticidal (ethyl acetate and methanol) and antidiabetic (ethanolic extract) activities. Physicochemical properties were carried out by using Association of Official Analytical Chemist methods; thin layer chromatography was carried out according to the Stahl method. Larvicidal activity and LD50 were studied against the third instar of Culex quinquefasciatus mosquito larvae to detect and extract toxicity. The ethanolic extracts of the roots were orally tested at the dose 200 mg/kg for the hypoglycemic effect on induced hyperglycemia in normal rats, assessed in the ethanol extract, and were compared with diabetic control and standards glibenclamide 10 mg/kg. Physiochemical parameters showed high rate in the nitrogen-free extract (69.6%), curd fiber (14.5%), crude proteins (8.15%), ether extract (3.75%), and both ash and moisture (2%), and high concentrations values were found in potassium (43 mg/l) followed by phosphorous (28.5 mg/l), calcium (15 mg/l), sodium (3.65 mg/l), and magnesium (0.145 mg/l). In this part, phytochemical compounds showed high amount of alkaloids, triterpene, flavonoids, tannins, sugars, and few amount of anthraquinone glycosides. Thin-layer chromatography (TLC) studies different colored phytochemical constituted with different Rf values. All the spots are colored under UV light, but some are localized colorless after spaying. The ethyl acetate (EtAc) extract showed eight spots, and the methanol (MeOH) extract showed thirteen spots. The larvicidal activity showed that the ethyl acetate extract was safe against mosquito larvae with an LD50 value 1412.54 (p
    Print ISSN: 2090-2247
    Electronic ISSN: 2090-2255
    Topics: Biology , Chemistry and Pharmacology
    Published by Hindawi
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  • 3
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    Geometry of the Solutions of Localized Induction Equation in the Pseudo-Galilean Space (2015)
    Hindawi
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    Publication Date: 2015-06-01
    Description: We study the surfaces corresponding to solutions of the localized induction equation in the pseudo-Galilean space . We classify such surfaces with null curvature and characterize some special curves on these surfaces in .
    Print ISSN: 1687-9120
    Electronic ISSN: 1687-9139
    Topics: Mathematics , Physics
    Published by Hindawi
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  • 4
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    Bernstein Series Solution of a Class of Lane-Emden Type Equations (2013)
    Hindawi
    Details
    Publication Date: 2013-04-10
    Description: The purpose of this study is to present an approximate solution that depends on collocation points and Bernstein polynomials for a class of Lane-Emden type equations with mixed conditions. The method is given with some priori error estimate. Even the exact solution is unknown, an upper bound based on the regularity of the exact solution will be obtained. By using the residual correction procedure, the absolute error can be estimated. Also, one can specify the optimal truncation limit which gives a better result in any norm. Finally, the effectiveness of the method is illustrated by some numerical experiments. Numerical results are consistent with the theoretical results.
    Print ISSN: 1024-123X
    Electronic ISSN: 1563-5147
    Topics: Mathematics , Technology
    Published by Hindawi
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  • 5
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    A Comparison in Mechanical Properties of Cermets of Calcium Silicate with Ti-55Ni and Ti-6Al-4V Alloys for Hard Tissues Replacement (2014)
    Hindawi
    Details
    Publication Date: 2014-11-04
    Description: This study investigated the impact of calcium silicate (CS) content on composition, compressive mechanical properties, and hardness of CS cermets with Ti-55Ni and Ti-6Al-4V alloys sintered at 1200°C. The powder metallurgy route was exploited to prepare the cermets. New phases of materials of Ni16Ti6Si7, CaTiO3, and Ni31Si12 appeared in cermet of Ti-55Ni with CS and in cermet of Ti-6Al-4V with CS, the new phases Ti5Si3, Ti2O, and CaTiO3, which were emerged during sintering at different CS content (wt%). The minimum shrinkage and density were observed in both groups of cermets for the 50 and 100 wt% CS content, respectively. The cermets with 40 wt% of CS had minimum compressive Young’s modulus. The minimum of compressive strength and strain percentage at maximum load were revealed in cermets with 50 and 40 wt% of CS with Ti-55Ni and Ti-6Al-4V cermets, respectively. The cermets with 80 and 90 wt% of CS showed more plasticity than the pure CS. It concluded that the composition and mechanical properties of sintered cermets of Ti-55Ni and Ti-6Al-4V with CS significantly depend on the CS content in raw cermet materials. Thus, the different mechanical properties of the cermets can be used as potential materials for different hard tissues replacements.
    Electronic ISSN: 1537-744X
    Topics: Natural Sciences in General
    Published by Hindawi
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  • 6
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    Detection of Prosthetic Knee Movement Phases via In-Socket Sensors: A Feasibility Study (2015)
    Hindawi
    Details
    Publication Date: 2015-04-06
    Description: This paper presents an approach of identifying prosthetic knee movements through pattern recognition of mechanical responses at the internal socket’s wall. A quadrilateral double socket was custom made and instrumented with two force sensing resistors (FSR) attached to specific anterior and posterior sites of the socket’s wall. A second setup was established by attaching three piezoelectric sensors at the anterior distal, anterior proximal, and posterior sites. Gait cycle and locomotion movements such as stair ascent and sit to stand were adopted to characterize the validity of the technique. FSR and piezoelectric outputs were measured with reference to the knee angle during each phase. Piezoelectric sensors could identify the movement of midswing and terminal swing, pre-full standing, pull-up at gait, sit to stand, and stair ascent. In contrast, FSR could estimate the gait cycle stance and swing phases and identify the pre-full standing at sit to stand. FSR showed less variation during sit to stand and stair ascent to sensitively represent the different movement states. The study highlighted the capacity of using in-socket sensors for knee movement identification. In addition, it validated the efficacy of the system and warrants further investigation with more amputee subjects and different sockets types.
    Electronic ISSN: 1537-744X
    Topics: Natural Sciences in General
    Published by Hindawi
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  • 7
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    Sustainability, Vol. 11, Pages 3668: The Need to Amend IMO’s EEDI to Include a Threshold for Performance in Waves (Realistic Sea Conditions) to Achieve the Desired GHG Reductions (2019)
    MDPI
    Details
    Publication Date: 2019
    Description: The International Maritime Organization (IMO) has established the Energy Efficiency Design Index (EEDI) as the most important policy measure to reduce greenhouse gas (GHG) emissions from shipping. A vessel’s EEDI is based on sea trials at delivery, and vessels cannot exceed a threshold for emitted CO2 per ton-mile, depending on vessel type and size. From other industries such as cars we have learnt that testing methods must reflect realistic operating conditions to deliver the desired emission reductions. Present sea-trial procedures for EEDI adjust to ‘calm water conditions’ only, as a comparative basis, despite calm sea being the exception at sea. We find that this adjustment procedure excessively rewards full bodied ‘bulky’ hulls which perform well in calm water conditions. In contrast, hull forms optimized with respect to performance in realistic sea-conditions are not rewarded with the current EEDI procedures. Our results indicate that without adjusting the testing cycle requirements to also include a threshold for performance in waves (real sea), the desired reductions will be short on targets and GHG emissions could potentially increase.
    Electronic ISSN: 2071-1050
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 8
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    Remote Sensing, Vol. 11, Pages 1875: Evaluation of Remotely-Sensed and Model-Based Soil Moisture Products According to Different Soil Type, Vegetation Cover and Climate Regime Using Station-Based Observations over Turkey (2019)
    MDPI
    Details
    Publication Date: 2019
    Description: This study evaluates the performance of widely-used remotely sensed- and model-based soil moisture products, including: The Advanced Scatterometer (ASCAT), the Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E), the European Space Agency Climate Change Initiative (ESA-CCI), the Antecedent Precipitation Index (API), and the Global Land Data Assimilation System (GLDAS-NOAH). Evaluations are performed between 2008 and 2011 against the calibrated station-based soil moisture observations collected by the General Directorate of Meteorology of Turkey. The calibration of soil moisture observing sensors with respect to the soil type, correction of the soil moisture for the soil temperature, and the quality control of the collected measurements are performed prior to the evaluation of the products. Evaluation of remotely sensed- and model-based soil moisture products is performed considering different characteristics of the time series (i.e., seasonality and anomaly components) and the study region (i.e., soil type, vegetation cover, soil wetness and climate regime). The systematic bias between soil moisture products and in situ measurements is eliminated by using a linear rescaling method. Correlations between the soil moisture products and the in situ observations vary between 0.57 and 0.87, while the root mean square errors of the products versus the in situ observations vary between 0.028 and 0.043 m3 m−3. Overall, according to the correlation and root mean square error values obtained in all evaluation categories, NOAH and ESA-CCI soil moisture products perform better than all the other model- and remotely sensed-based soil moisture products. These results are valid for the entire study time period and all of the sub-categories under soil type, vegetation cover, soil wetness and climate regime.
    Electronic ISSN: 2072-4292
    Topics: Architecture, Civil Engineering, Surveying , Geography
    Published by MDPI
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  • 9
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    Energies, Vol. 12, Pages 19: Formal Asymptotic Analysis of Online Scheduling Algorithms for Plug-In Electric Vehicles’ Charging (2018)
    MDPI
    In: Energies
    Details
    Publication Date: 2018
    Description: A large-scale integration of plug-in electric vehicles (PEVs) into the power grid system has necessitated the design of online scheduling algorithms to accommodate the after-effects of this new type of load, i.e., PEVs, on the overall efficiency of the power system. In online settings, the low computational complexity of the corresponding scheduling algorithms is of paramount importance for the reliable, secure, and efficient operation of the grid system. Generally, the computational complexity of an algorithm is computed using asymptotic analysis. Traditionally, the analysis is performed using the paper-pencil proof method, which is error-prone and thus not suitable for analyzing the mission-critical online scheduling algorithms for PEV charging. To overcome these issues, this paper presents a formal asymptotic analysis approach for online scheduling algorithms for PEV charging using higher-order-logic theorem proving, which is a sound computer-based verification approach. For illustration purposes, we present the complexity analysis of two state-of-the-art online algorithms: the Online cooRdinated CHARging Decision (ORCHARD) algorithm and online Expected Load Flattening (ELF) algorithm.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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  • 10
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    Energies, Vol. 12, Pages 3530: The Conundrum of Carbon Trading Projects towards Sustainable Development: A Review from the Palm Oil Industry in Malaysia (2019)
    MDPI
    In: Energies
    Details
    Publication Date: 2019
    Description: Palm oil’s utilization as a renewable energy (RE) source has led the government to intervene by introducing emission reduction projects. Carbon trading projects are part of the strategic direction adopted within the climate mitigation plan and sustainability drive in the palm oil industry. The perquisites and opportunities encountered within emissions trading are expected to aid palm oil producers economically, environmentally, and socially. This study addresses and analyses how the carbon trading projects’ targets in Malaysia can be achieved, the problematic, and pressing issues around their implementation and whether these projects are sustainable and create a positive impact. This paper is based on literature reviews and semi-structured interviews with expert palm oil producers in Malaysia. The findings have revealed that carbon trading implementation in Malaysia has delivered new insights towards the international climate policy approach on the feasibility and impact of long-term sustainability goals. However, the impact of the implementation needs support from the government for further development. In conclusion, the major contribution of this study is that the carbon trading implementation in Malaysia complies with the objectives and principles of sustainable development and creates a significant influx in investment for Malaysia’s economic growth.
    Electronic ISSN: 1996-1073
    Topics: Energy, Environment Protection, Nuclear Power Engineering
    Published by MDPI
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