检索结果-南通市图书馆

A Review on Thermophysical Properties and Nusselt Number Behavior of Al2O3 Nanofluids in Heat Exchangers

在线全文

学校读者我要写书评

暂无评论

journal of Thermal Science 2021年第2期30卷 418-431页

作者： issa roy jean College of Engineering West Texas A&M UniversityCanyonTexas 79016USA

During the last several years,the increase in cooling power requirements for heat exchangers have led to an escalation in heat transfer studies being performed on the use of nanofluids as heat transfer ***,limited effort has been attempted to relate and interpret these findings or the anomalies associated with *** paper compiles test data from several studies conducted on different types of heat *** this review,a concentrated effort is spent to clarify the ambiguities regarding the effect of nanoparticle size on the nanofluid thermal conductivity and Nusselt *** show that the nanofluid thermal conductivity is not influenced by the nanoparticle size,but by the clustering of the particles *** less compact the structure of the nanoparticle clustering is,the greater the enhancement in the nanofluid thermal conductivity *** were also compiled to interpret the relation between the nanofluid flow pattern,nanoparticles volume fraction in the base fluid,and the convective heat *** results from the majority of the heat exchanger studies show an increase in the heat transfer coefficient with the increase in nanoparticle volume ***,studies conducted on plate heat exchanges display some *** the majority of the heat exchanger studies with the exception of few,the decrease in the nanoparticle size is shown to result in an enhancement of the bulk fluid Nusselt *** test data also reveal that the effectiveness of the alumina nanoparticles is dependent on the flow *** increase in the nanoparticles concentration is shown to result in an increase in the nanofluid heat transfer enhancement as the fluid is transitioning from laminar to turbulent *** general,the smaller the nanoparticle size is,the greater the enhancement in the fluid Nusselt number is.

关键词： heat exchanger Nusselt number alumina nanofluid

Performance Prediction of a Multi-Stage Wind Tower for Indoor Cooling

在线全文

学校读者我要写书评

暂无评论

journal of Thermal Science 2012年第4期21卷 327-335页

作者： roy j. issa Byungik Chang Department of Engineering and Computer Science West Texas A&M University Canyon

A theoretical model is developed to establish an indepth understanding of the performance of a three-stage wind tower with a bypass system for indoor cooling in rural dry and hot climates. Model simulations are presented for a wide range of ambient conditions that include inlet wind speed, inlet temperature and relative humidity. Simulation results provide an insight into the desirable water flow rates and air-to-water loadings for comfort zone tem-peratures and relative humidity levels at the exit of the wind tower. Simulations show wind towers with variable cross-sections provide an increase in the cooling power for the same inlet wind speed, inlet air temperature and relative humidity when compared to wind towers with a constant cross-section. The study shall lead to a better understanding to designing wind towers that are both environmentally friendly and energy efficient.

关键词： Wind tower Cooling power Cooling effectiveness Relative humidity

Physics-informed machine learning for metamodeling thermal comfort in non-air-conditioned buildings

在线全文

学校读者我要写书评

暂无评论

Building Simulation 2023年第2期16卷 299-316页

作者： issa jaffal Laboratoire du froid et des systèmesénergétiques et thermiques(Lafset) CnamHESAM UniversitéParisFrance

There is a growing need for accurate and interpretable machine learning models of thermal comfort in ***-informed machine learning could address this need by adding physical consistency to such *** paper presents metamodeling of thermal comfort in non-air-conditioned buildings using physics-informed machine *** studied metamodel incorporated knowledge of both quasi-steady-state heat transfer and dynamic simulation *** thermal comfort in an office located in cold and hot European climates was studied with the number of overheating hours as index.A one-at-a-time method was used to gain knowledge from dynamic simulation with TRNSYS *** knowledge was used to filter the training data and to choose probability distributions for metamodel forms alternative to *** response of the dynamic model was positively skewed;and thus,the symmetric logistic and hyperbolic secant distributions were inappropriate and outperformed by positively skewed *** physical knowledge into the metamodel was much more effective than doubling the size of the training *** highly flexible Kumaraswamy distribution provided the best performance with R2 equal to 0.9994 for the cold climate and 0.9975 for the hot ***-informed machine learning could combine the strength of both physics and machine learning models,and could therefore support building design with flexible,accurate and interpretable metamodels.

关键词： adaptive thermal comfort overheating physics-informed machine learning metamodel surrogate model probability distributions

Physical modeling of behaviors of cast-in-place concrete piled raft compared to free-standing pile group in sand

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

journal of Rock Mechanics and Geotechnical Engineering 2018年第4期10卷 703-716页

作者： Mehdi Sharafkhah issa Shooshpasha Faculty of Civil Engineering Babol Noshiravani University of Technology

Similar to free-standing pile groups, piled raft foundations are conventionally designed in which the piles carry the total load of structure and the raft bearing capacity is not taken into account. Numerous studies indicated that this method is too conservative. Only when the pile cap is elevated from the ground level,the raft bearing contribution can be neglected. In a piled raft foundation, pileesoileraft interaction is complicated. Although several numerical studies have been carried out to analyze the behaviors of piled raft foundations, very few experimental studies are reported in the literature. The available laboratory studies mainly focused on steel piles. The present study aims to compare the behaviors of piled raft foundations with free-standing pile groups in sand, using laboratory physical models. Cast-in-place concrete piles and concrete raft are used for the tests. The tests are conducted on single pile, single pile in pile group, unpiled raft, free-standing pile group and piled raft foundation. We examine the effects of the number of piles, the pile installation method and the interaction between different components of foundation. The results indicate that the ultimate bearing capacity of the piled raft foundation is considerably higher than that of the free-standing pile group with the same number of piles. With installation of the single pile in the group, the pile bearing capacity and stiffness increase. Installation of the piles beneath the raft decreases the bearing capacity of the raft. When the raft bearing capacity is not included in the design process, the allowable bearing capacity of the piled raft is underestimated by more than 200%. This deviation intensifies with increasing spacing of the piles.

关键词： Free-standing pile group Piled raft Pileesoileraft interaction Physical modeling Cast-in-place concrete piles

Molecular landscape in acute myeloid leukemia: where do we stand in 2016

在线全文

学校读者我要写书评

暂无评论

Cancer Biology & Medicine 2016年第4期13卷 474-482页

作者： Karam Al-issa Aziz Nazha Leukemia Program Department of Hematology and Oncology Cleveland Clinic Taussig Cancer Institute

Acute myeloid leukemia(AML) is a clonal disorder characterized by the accumulation of complex genomic alterations that define the disease pathophysiology and overall outcome. Recent advances in sequencing technologies have described the molecular landscape of AML and identified several somatic alterations that impact overall survival. Despite all these advancement, several challenges remain in translating this information into effective therapy. Herein we will review the molecular landscape of AML and discuss the impact of the most common somatic mutations on disease biology and outcome.

关键词： Acute myeloid leukemia molecular landscape somatic mutations

Mathematical modeling of nanoscale MOS capacitance in the presence of depletion and energy quantization in a poly-silicon gate

在线全文

学校读者我要写书评

暂无评论

journal of Semiconductors 2010年第11期31卷 5-8页

作者： Amit Chaudhry j.N.roy Institute of Engineering and Technology Panjab University Solar Semiconductor Pvt.Ltd.

A model has been developed to study the effect of depletion and energy quantization at the poly-silicon /oxide interface on the behavior of a nanometer scale n-MOSFET.A model of inversion charge density,including the inversion layer quantization using the variation approach in the substrate,has also been *** the exact calculations of the polygate potential under the depletion and quantization conditions,a C-V model has been developed. All the results have been compared with the numerical models reported in existing literature and they show good agreement.

关键词： BSIM inversion layers MOS devices quantization poly-depletion poly-quantization

Evaluation and modification of some empirical and semi-empirical approaches for prediction of area-storage capacity curves in reservoirs of dams

在线全文

学校读者我要写书评

暂无评论

International journal of Sediment Research 2017年第1期32卷 127-135页

作者： issa E.issa Nadhir Al-Ansari Govand Sherwany Sven Knutsson Department of Civil Environmental and Natural Resources EngineeringLulea University of Technology Department of Dams and Water Resources Engineering University of Mosul

The storage capacity of reservoirs is gradually reduced due to sediment accumulation that causes changes in the area-storage capacity（ASC） *** these curves and predicting their future change is an important issue for planners,designers and operators of *** empirical and semiempirical approaches have been suggested for establishing and predicting the future changes for these *** this study four empirical and semi-empirical methods were evaluated and three of them were modified to be used for the prediction of changes in the ASC curves due to sedimentation,based on the existing sedimentation survey data for 11 reservoirs in the *** evaluation,these approaches were reviewed and used to determine sedimentation depth and establishing the ASC curves for the Mosul dam reservoir（MDR）,which is the biggest hydraulic structure on the River Tigris in northern *** started operating in 1986 with a storage capacity of 11.11 km;and a water surface area 380 km2 at normal operation stage（330 m a.s.l.）.The results obtained from these methods were evaluated using observed bathymetric survey data that had been collected in 2011 after 25 years of the operation of the *** evaluation results showed three methods had presented more accurate results for estimating water depth or sedimentation depth at dam site with percentage error about 1.06-3.30%.Whilst for establishing ASC curves,one method presented good agreement result with survey ***,ASC and sedimentation depths at dam site of MDR for periods 50,75,100 and 125 years were estimated using the modified approaches and the area reduction *** results of the modified methods provided reasonable agreement when compared with the area reduction method proposed by the *** of Reclamation and the agreement became better with an increase in time period.

关键词： Area-capacity curves Reservoir sedimentation Area reduction method Mosul dam

Tandem synthesis of functionalized hexaalkyl benzoisoquinolinopyrrolonaphthyridine-hexacarboxylate, via isoquinoline based multi-component reaction

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2013年第11期24卷 979-983页

作者： Mohammad Piltan issa Yavari Loghman Moradi Department of Chemistry Sanandaj Branch Islamic Azad University Chemistry Department Tarbiat Modares University Department of Chemistry Faculty of Science University of Kurdistan

An expedient,synthetic method to fused polycyclic derivatives of isoquinoline is described via tandem reaction of isoquinoline,dialkyl acetylenedicarboxylates and dialkyl chloromalonate.

关键词： Isoquinoline Tandem reaction Acetylenic esters Dialkyl chloromalonate

Nanoscale strained-Si MOSFET physics and modeling approaches:a review

在线全文

学校读者我要写书评

暂无评论

journal of Semiconductors 2010年第10期31卷 19-23页

作者： Amit Chaudhry j.N.roy Garima joshi University Institute of Engineering and Technology Panjab University Solar Semiconductor Private Limited

An attempt has been made to give a detailed review of strained silicon technology. Various device models have been studied that consider the effect of strain on the devices, and comparisons have been drawn. A review of some modeling issues in strained silicon technology has also been outlined. The review indicates that this technology is very much required in nanoscale MOSFETs due to its several potential benefits, and there is a strong need for an analytical model which describes the complete physics of the strain technology.

关键词： mobility SiGe strained-Si technology CAD