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Effects of hydrogel-encapsulated bacteria on the healing efficiency and compressive strength of concrete

Journal of Road Engineering 2023年第2期3卷 156-170页

作者： Ricardo Hungria marwa m.hassan momen mousa Bert S.Turner Department of Construction management Louisiana State UniversityBaton RougeLA 70803USA Department of Engineering Technology Sam Houston State UniversityHuntsvilleTX 77341USA

microbial-induced calcium carbonate precipitation is a promising technology for self-healing concrete due to its capability to seal *** main goal of this study was to evaluate the effects of adding hydrogelencapsulated bacteria on the compressive strength and the self-healing efficiency of *** achieve this objective,12 sets of mortar samples were prepared,including three different mineral precursors(magnesium acetate,calcium lactate,and sodium lactate),at two concentrations(67.76 and 75.00 mm/L),and under two different biological conditions(with and without bacteria).In addition,a set of plain mortar samples was prepared to serve as a *** each sample set,three mortar cubes and three beams were prepared and subjected to compression and flexural strength *** the compression tests,it was found that the sample containing calcium lactate along with yeast extract and bacteria displayed the best *** for the flexural tests,once cracked,the beams were subjected to 28 d of wet/dry cycles(16 h of water immersion and 8 h of drying),where the bottom crack width was monitored(at 0,3,7,14,28 d of wet/dry cycles).Once the sample with the highest healing efficiency was identified(the one containing calcium lactate and hydrogel-encapsulated bacteria),the study was scaled up to concrete *** sets of concrete cylinders(consisting of three control samples and three samples with bacteria along with calcium lactate)were tested under compression in order to evaluate the effect of the bacteria-precursor combination on the concrete mechanical *** samples that yielded the greatest compressive strength were the ones containing calcium lactate and bacteria,displaying an improvement of 17%as compared to the control ***,a flexural strength recovery analysis was performed on the concrete specimens revealing that the control showed better flexural strength recovery than the bacteriacontaining variant(41.5%vs.26.1%)after

关键词： Self-healing concrete Bioconcrete microbial induced calcium carbonate precipitation Precursor

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East African topography and volcanism explained by a single,migrating plume

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Geoscience Frontiers 2020年第5期11卷 1669-1680页

作者： Rakib hassan Simon E.Williams michael Gurnis Dietmar muller School of Geosciences Room 412Madsen Building F09 Eastern AvenueThe University of SydneyNSW2006Australia Seismological Laboratory California Institute of TechnologyPasadenaCA91125USA Now at Geoscience Australia GPO Box 378CanberraACT2601Australia State Key Laboratory of Continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China

Anomalous topographic swells and Cenozoic volcanism in east Africa have been associated with mantle *** models involving one or more fixed plumes beneath the northeastward migrating African plate have been suggested to explain the space-time distribution of magmatism in east *** devise paleogeographically constrained global models of mantle convection and,based on the evolution of flow in the deepest lower mantle,show that the Afar plume migrated southward throughout its *** models suggest that the mobile Afar plume provides a dynamically consistent explanation for the spatial extent of the southward propagation of the east African rift system(EARS),which is difficult to explain by the northeastward migration of Africa over one or more fixed plumes alone,over the last≈45 *** further show that the age-progression of volcanism associated with the southward propagation of EARS is consistent with the apparent surface hotspot motion that results from southward motion of the modelled Afar plume beneath the northeastward migrating African *** models suggest that the Afar plume became weaker as it migrated southwards,consistent with trends observed in the geochemical record.

关键词： Numerical mantle flow models Deep mantle flow LLSVP morphology Plume dynamics Plume motion Dynamic topography

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Low-cost sensorless control of four-switch,brushless DC motor drive with direct back-EmF detection

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2009年第2期10卷 201-208页

作者： Abolfazl HALVAEI NIASAR Abolfazl VAHEDI hassan mOGHBELLI Department of Electrical Engineering Faculty of EngineeringUniversity of Kashan Center of Excellence for Power System Automation and Operation Iran University of Science and Technology Department of Science and mathematics Texas A&M University at Qatar

We propose a position sensorless control scheme for a four-switch,three-phase brushless DC motor drive,based on the zero crossing point detection of phase back-EmF voltages using newly defined error functions(EFs). The commutation in-stants are 30° after detected zero crossing points of the EFs. Developed EFs have greater magnitude rather than phase or line voltages so that the sensorless control can work at a lower speed range. moreover,EFs have smooth transitions around zero voltage level that reduces the commutation errors. EFs are derived from the filtered terminal voltages vao and vbo of two low-pass filters,which are used to eliminate high frequency noises for calculation of the average terminal voltages. The feasibility of the proposed sensorless control is demonstrated by simulation and experimental results.

关键词： Brushless DC motor Four-switch inverter Sensorless control Back-EmF voltage sensing DSP

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Finite Element Analysis of Porous Titanium Alloy Hip Stem to Evaluate the Biomechanical Performance During Walking and Stair Climbing

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Journal of Bionic Engineering 2019年第6期16卷 1103-1115页

作者： Sami Emad Alkhatib hassan mehboob Faris Tarlochan School of mechanical and Chemical Engineering M050The University of Western Australia35 Stirling HighwayCrawleyPerthWA6009Australia Department of Engineering management College of EngineeringPrince Sultan UniversityRiyadhKingdom of Saudi Arabia Department of mechanical and Industrial Engineering College of EngineeringQatar UniversityDohaQatar

Despite the success of cementless hip stem,stress shielding still presents a serious problem leading to bone *** incorporating porous cellular structures represent a promising ***,this study validates the finite element models of titanium(Ti)alloy(Ti-6Al-4V)porous stem and effective porous *** effective porous stems with strut thicknesses 0.33 mm-1.25 mm(18%-90%porosity)under different loading conditions were *** results of finite element models revealed that changing the load type and porosity affect stress *** loads yield the maximum stress levels while walking loads result in the lowest stresses in the ***,the point load results in the maximum stress shielding and micromotions(-19% to 18%,40μm to 703μm),as compared to walking(-17.5% to 3%,35μm to 242μm)and climbing loads(-7% to 1.6%,30μm to 221 μm).Finally,effective porous stems of strut thickness 0.87 mm exhibit the lowest stress shielding signals(<5%)under all loading conditions.

关键词： porous cellular microstructures porous hip stems physiological loads finite element analysis stress shielding

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Using artificial neural network to predict velocity of sound in liquid water as a function of ambient temperature, electrical and magnetic fields

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Journal of Ocean Engineering and Science 2016年第3期1卷 203-211页

作者： Hashem Nowruzi hassan Ghassemi Department of Ocean Engineering Amirkabir University of Technology(Tehran Polytechnic)TehranIran

One of the main thermophysical properties of liquid water is velocity of ***,the effect of different externalities on velocity of sound in liquid water is not well ***,in current study,by designing an artificial neural network(ANN)velocity of sound in liquid water under different externalities is *** externalities are ambient temperature from 272.65 K to 348.43 K,different electrical fields in range of 0 V/m to 4.03E+9 V/m and magnetic fields in range of 0-10.0594 *** prepare of reference dataset for entry to ANN,numerical and experimental data as macroscopic reference data are extracted from microscopic characteristic of water HB *** order to achieve an appropriate ANN,ANN architecture sensitivity analysis is conducted by using an iterative *** procedure in the selected feed-forward back propagation ANN is done by hyperbolic transfer ***,Levenberg-marquardt algorithm is utilized for the optimization *** output showed that the maximum mSE in prediction of velocity of sound is ***,the minimum of correlation coefficient in prediction of velocity of sound is *** on the ANNs outputs,weights and bias,an equation to predict of velocity of sound in liquid water under intended externalities is ***,according to weight sensitivity analysis input of electrical fields with 63%relative importance percentage has a grater impression on the response variable of velocity of sound in liquid water.©2016 Shanghai Jiaotong *** by Elsevier B.V.

关键词： Artificial neural network Electrical field magnetic field Velocity of sound Temperature

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Relative performance of novel blast wave mitigation system to conventional system based on mitigation percent criteria

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Defence Technology（防务技术） 2021年第3期17卷 912-922页

作者： moustafa Esa mostafa S.Amin Ahmed hassan Eng.mechanics Dept. Military Technical CollegeKobry ElkobbahCairoEgypt Civil Eng.Dept. Military Technical CollegeKobry ElkobbahCairoEgypt

Recent researches focused on developing robust blast load mitigation systems due to the threats of terrorist *** of the main embraced strategies is the structural systems that use mitigation *** are developed from a combination of structural elements and described herein as conventional *** the promising techniques is that redirect the waves propagation through hollow *** blast wave propagation through tubes provides an efficient system since it combines many blast wave phenomena,such as reflection,diffraction,and *** this research,a novel blast load mitigation system,employed as a protection fence,is developed using a technique similar to the technique of the bent tube in manipulating the *** relative performance of the novel system to the conventional system is evaluated based on mitigation percent *** of both systems are calculated through numerical *** proposed novel system proved to satisfy high performance in mitigating the generated blast waves from charges weight up to 500 kg TNT at relatively small standoff distances(5 m and 8 m).It mitigates at least 94%of the blast waves,which means that only 6%of that blast impulse is considered as the applied load on the targeted structure.

关键词： Blast mitigation Blast barriers Protection system mitigation percent Protection evaluation

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Diatomaceous Deposits of Fayium, Egypt; Characterization and Evaluation for Industrial Application

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Chinese Journal Of Geochemistry 1999年第3期18卷 233-241页

作者： m.S.hassan I.A.IBRAHIm 等 CentralmetallurgicalResearchandDevelopmentInstitute B.O.Box87HelwanCairoEgypt CentralmetallurgicalR

The Holocene lacustrine diatomaceous earth of Fayium, South West of Cairo, has been studied to define its minerals, chemistry, petrography and physical properties. minerals were processed by way of calcination at 550℃, followed by acid leaching to reduce levels of mineral impurities. The diatomite is of biogenic opal A, with calcite as the main gangue mineral, quartz and clay minerals (smectite followed by kaolinite in abundance and a trace amount of illite). Silica in the diatomaceous earth accounts for about 63% on average.\; Positive correlation between CaO and CO\-2 indicates that Ca is present mainly as calcite. Al\-2O\-3, Fe\-2O\-3, mgO and K\-2O are attributed mainly to clay minerals. However, the physical properties of the diatomaceous earth as filter aids and filler for paints and plastics are poor because of general high levels of impurities. The technological performances of the diatomaceous earth have been significantly improved owing to upgrading of diatoms through mineral processing trials.

关键词：硅藻土矿床工业应用氧化钙矿物硅土

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From Baecklund Transformation to a Linear System of Sine-Gordon Theory in Superspace

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Chinese Physics Letters 2005年第7期22卷 1567-1569页

作者： m.Siddiq m.hassan DepartmentofPhysics UniversityofthePunjabQuaid-e-AzamCampusLahore-54590Pakistan

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Economic Development through medicinal and Aromatic Plants(mAPs) Cultivation in Hindu Kush Himalaya mountains of District Swat, Pakistan

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Journal of mountain Science 2015年第5期12卷 1292-1301页

作者： hassan SHER mary E. BARKWORTH Center for Plant Sciences and Biodiversity University of Swat Intermountain Herbarium Department of Biology Utah State University

Poverty is pervasive in the Swat Valley in northwestern Pakistan, and most people survive by farming small landholdings. However, many supplement their meager subsistence earnings by collecting and selling plant material for use in herbal medicine. This material is wild-harvested, but collectors seem not to fully appreciate the potential value of the plant material they collect nor the longterm impact their collection has on local plant populations. A model project supported by the International Food Policy Research Institute(IFPRI)persuaded small-scale farmers in four different villages to use some of their land for cultivating traditionally wild-harvested species of medicinal and aromatic plants(mAPs) with high market value. The farmers were provided seeds or rhizomes of five mAPs and asked to monitor their germination and growth on 25 m2 plots during a 12 month period. At the end of the study, growth and yield data from the four localities were compared and economic analyses conducted to determine the profitability of the species based on yields, prevailing market prices, and costs of production. Five of the cultivated species were subsequently marketed and their value evaluated:Sesamum indicum, Linum usitatissimum, Ocimum basilicum, Nigella sativa and Viola pilosa. The mAPs V. pilosa and O. basilicum were the most profitable,whereas Nigella sativa was the least profitable because of its low germination rate. The net income from all but Nigella was higher than that would have been earned by planting the same area with the predominant cereals or tomatoes. In addition to demonstrating the feasibility and financial benefits of cultivating mAPs as a cash crop, this model study identified a number of additional steps that would increase the benefits of mAPs cultivation in this area.A combination of specialized education, market infrastructure development and a small loans program would enable farmers to increase their agricultural income without damaging the area's pl

关键词： Biological diversity medicinal plant Aromatic plant Agriculture productivity Traditionalcrops Economic analysis Himalaya mountains

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Smart component monitoring system increases the efficiency of photovoltaic plants

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Clean Energy 2023年第2期7卷 I0001-I0009,312页

作者： hassan Yazdani mehdi Radmehr Alireza Ghorbani Department of Electrical Engineering Sari BranchIslamic Azad UniversitySariIran

Due to the increasing expansion of renewable energy,especially the widespread installation of solar power plants worldwide,to better exploit and increase the efficiency and quality of power generation,we need to closely monitor the performance of important components of the *** this study,using an innovative smart monitoring system and electronic sensors,we monitored compo-nents such as power in photovoltaic(PV)arrays in real time,including the phenomenon of hot spots as an example of power loss in PV *** of hot spots is very difficult to deal with in a large power *** results also demonstrated smart monitoring that increased detection speed and increased the efficiency rate per supervisory technician by≤36% compared with the previous ef-ficiency rate,which was 10% per technical staff,and increased the quality of the operation of each solar power *** this paper,meteorological data were coordinated with research data to validate the ***,to compare the results of using the smart monitoring method with the conventional observation method,a complete diagram of a 5-kW solar system in mATLAB■2018 was simulated and output diagrams were ***,to provide a comprehensive validation,our research results were com-pared with technical data obtained from a local 5-kW solar power plant located in Sari,Iran(36°33ʹ48″N,53°03ʹ36″E)with an average annual irradiation of 1490 kWh/m^(2).When the simulation results and research are analysed,it is clear that the smart and real-time monitoring approach brings various benefits to solar power plants.

关键词： photovoltaic power plant online monitoring efficiency solar cell power PV modules

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