检索结果-南通市图书馆

A quasi-steady state model for predicting the heating requirements of conventional greenhouses in cold regions

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2018年第1期5卷 33-46页

作者： md shamim Ahamed Huiqing Guo Karen Tanino Division of Environmental Engineering University of SaskatchewanCanada Department of Mechanical Engineering University of SaskatchewanCanada Department of Plant Sciences University of SaskatchewanCanada

A time-dependent,quasi-steady state thermal model(GREENHEAT)based on the lumped estimation of heat transfer parameters of greenhouses has been developed to predict the hourly heating requirements of conventional *** model was designed to predict the hourly heating requirements based on the input of greenhouse indoor environmental control parameters,physical and thermal properties of crops and construction materials,and hourly weather data including temperature,relative humidity,wind speed,and cloud *** model includes all of the heat transfer parameters in greenhouses including the heat loss for plant evapotranspiration,and the heat gain from environmental control *** show that the predicted solar radiation data from the solar radiation sub-model are a reasonable fit with the data from the National Solar Radiation Database(NSRDB).Thermal analysis indicates environmental control systems could reduce 13–56%of the total heating requirements over the course of a year in the study *** the winter season,the highest amount of greenhouse heat is lost due to conduction and convection,and the heat used for evapotranspiration is dominant in the ***,the model was validated with actual heating data collected from a commercial greenhouse located in Saskatoon,and the results show that the model satisfactorily predicts the greenhouse heating requirements.

关键词： Heating model Solar radiation Supplemental lighting Evapotranspiration

Visible light communication for intelligent transportation systems:A review of the latest technologies

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 Traffic and Transportation Engineering(English Edition) 2021年第4期8卷 483-492页

作者： Khaled Shaaban md Hosne Mobarok shamim Khadija Abdur-Rouf Department of Engineering Utah Valley UniversityOremUT 84058United States Department of Electrical and Computer Engineering McGill UniversityMontréalQC H3A 0E9Canada Department of Civil&Architectural Engineering Qatar UniversityDohaQatar

In seeking to improve traffic congestion and safety on roads and highways,there has been an increased interest in intelligent transportation systems(ITS).The emerging visible light communication(VLC)technology is a new candidate to enable wireless access in *** purpose of this study is to present a comprehensive review of the current studies related to *** VLC facilitates illumination and data communication simultaneously,it reduces energy consumption ***,VLC is immune to electromagnetic interference,provides high data security,and utilizes unregulated visible light spectrum,showing promise as a potentially cheaper alternative to existing radio frequency(RF)based ***,recent advances in semiconductor materials and solid-state technologies have enabled the development of efficient light-emitting diodes(LEDs)and laser diodes(LDs)which are used as transmitters in a VLC *** 10 s of Gbits/s data rate has been demonstrated in indoor VLC links,successful implementation of it in outdoor environments requires further research to overcome the challenges presented by environmental factors,unwanted lights,non-line of sight communication,directional radiation pattern,frequent fragmentation,and so ***,in recent years,semiconductor LDs have been garnering more attention since they can transmit more data over longer distances due to their high quantum efficiency and modulation bandwidth compared to *** a result,urban planners,policy-makers,transportation engineers,and vehicle manufacturers are considering LD-based VLC to facilitate vehicle-to-vehicle and vehicle-to-infrastructure ***,this paper reviews and compares the most recent developments in VLC technologies,identifies their benefits and potential use in ITS applications,discusses the probable barriers for their implementation in our existing transportation infrastructure,and suggests future research directions and recommendations to overcome

关键词： Vehicle-to-vehicle(V2V)communication Vehicle-to-infrastructure(V2I) communication Light-emitting diodes Laser diodes Internet of things Transportation network

Heating demand and economic feasibility analysis for year-round vegetable production in Canadian Prairies greenhouses

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Information Processing in Agriculture 2019年第1期6卷 81-90页

作者： md shamim Ahamed Huiqing Guo Lisa Taylor Karen Tanino Department of Farm Power and Machinery Bangladesh Agricultural UniversityBangladesh Department of Mechanical Engineering University of SaskatchewanCanada Department of Plant Sciences University of SaskatchewanCanada

Greenhouse vegetable production in Canadian Prairies is important for creating a sustainable regional food economy,especially in northern *** study included the estimation of heating demand for year-round production and evaluation of the economic feasibility of greenhouse vegetable production(tomato,cucumber,and pepper)in a conceptually designed greenhouse(0.6 ha)located in remote northern communities in Saskatchewan,*** heating simulation was based on a greenhouse heating simulation model(GREENHEAT)developed by the authors *** simulation results showed that the annual heating requirement for the production of tomato,cucumber,and pepper are 1486 MJ m^2,1657 MJ m^2,and 1754 MJ m^2,*** economic analysis indicates the net return(NR)from the production of tomato,cucumber,and pepper,are C$69.2/m^2(in Canadian dollar,CAD),C$41.5/m^2,and C$43.8/m^2,respectively,based on the market price C$3.5/kg,C$2.7/kg,and C$8.0/kg,and yields of 55.0 kg m^-2,65.0 kg m^-2,and 23.0 kg m^-*** net present value(NPV)for the tomato,cucumber,and pepper production are C$1.9 M,C$1.2 M,and C$1.1 M,respectively,and the benefit-cost ratio(BCR)are 1.38,1.21,and *** economic feasibility analysis indicates the year-round production of vegetables in a greenhouse at remote northern Saskatchewan would be economically profitable.

关键词： Northern latitudes Heating requirement Economic analysis Sensitivity analysis Year-round production

A monodisperse-aerosol generation system： Design, fabrication and performance

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Particuology 2017年第5期15卷 118-125页

作者： Amit md. Estiaque Arefin M.H. Masud Mohammad U.H. Joardder md. shamim Akhter Department of Mechanical Engineering Rajshahi University of Engineering and Technology Rajshahi Bangladesh

Monodisperse aerosols are essential in many applications, such as filter testing, aerosol instrument calibration, and experiments for validating models. This paper describes the design principle, construction, and performance of a monodisperse-aerosol generation system that comprises an atomizer, virtual impactor, microcontroller-based isokinetic probe, wind tunnel, and velocity measurement device. The size distribution of the produced monodisperse aerosols was determined by an optical particle counter. The effects of atomizer characteristics, the rates of minor and major flow, and solution criteria were investigated. It was found that all these parameters affect the generation of monodisperse aerosol. Finally, the expected geometric standard deviation （〈1.25） of monodisperse aerosol particles was obtained with the most suitable atomizer for 10% oleic acid in ethyl alcohol solution with 5%-15% minor flow, where the ratio between the nozzle-to-probe distance and acceleration-nozzle-exit diameter was 0.66. The con- structed monodisperse-aerosol-generation system can be used for instrumental calibration and aerosol research.

关键词： Aerosol generation Monodisperse Design Sampling Counting

Evaluation of structure,dielectric and electrical properties of(Li/Ta/Sb)modified(Na,K)NbO_(3) lead-free ceramics with excess Na concentration

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 Advanced Dielectrics 2017年第6期7卷 12-20页

作者： md.Kashif shamim Arpana Singh Seema Sharma Materials Research Laboratory Department of Physics A.N CollegePatna 800013India

Polycrystalline perovskite structured Li_(0.04)(Na_(0.54+x) K_(0.46))_(0.96)(Nb_(0.81)Ta_(0.15)Sb_(0.04))O_(3) ceramics with x¼0:00,0.005 and 0.01 mole excess Na concentration were prepared by solid state sintering *** present study relates the role of excess Na addition with the stoichiometry,density,structure,dielectric and ferroelectric properties of the samples.X-ray diffraction(XRD)pattern exhibits single phase orthorhombic *** characteristic Raman modes were observed due to translational modes of cations and vibrational modes of NbO_(6) octahedra and no structural phase transition were *** confirms the formation of single phase perovskite structure and is consistent with XRD *** dielectric permittivity increases about two times,while dielectric loss decreases by four times for χ=0.01 *** electrical measurements carried by Complex Impedance spectroscopic analysis suggest negative temperature coefficient of resistance(NTCR)behavior.

关键词： Perovskite dielectric properties negative temperature coefficient of resistance(NTCR) ferroelectric properties leakage current

Dielectric relaxation and modulus spectroscopy analysis of(Na_(0.47)K_(0.47)Li_(0.06))NbO_(3) ceramics

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 Advanced Dielectrics 2017年第3期7卷 37-47页

作者： md Kashif shamim Seema Sharma Sangeeta Sinha Eqra Nasreen Materials Research Laboratory Department of Physics A.N.College Patna 800013India Department of Environmental Science A.N.College Patna 800013India

We have investigated the structure,dielectric and electrical properties of lead-free polycrystalline (Na_(0.47)K_(0.47)Li_(0.06))NbO_(3) ceramics as a function of temperature and frequency in order to understand the intrinsic contribution of grain/bulk and grain boundary effects toward the dielectric response as well as the electrical conduction mechanism in the samples fabricated by microwave sintering method.X-ray diffraction analysis exhibits perovskite structure with orthorhombic symmetry,which is well supported by the Raman spectroscopic analysis.A minor secondary impurity phase of tungsten bronze structure was observed for samples sintered at 1050℃,which gets weaker for samples sintered at 1150℃.Dielectric permittivity was enhanced by 50%,although there was a reduction in the dielectric loss by about 50%at Curie temperature(450℃)for samples sintered at 1150℃.Complex impedance spectroscopic analysis indicated non-Debye-type dielectric relaxation present in the samples,and this phenomenon followed thermally activated process related to hopping *** plot showed the negative temperature coefficient of resistance,characteristic of the samples.

关键词： Lead-free piezo-ceramics dielectric properties AC impedance spectroscopy dielectric relaxation negative temperature coefficient of resistance(NTCR).

Pathogens causing diarrhoea among Bangladeshi children with malignancy: Results from two pilot studies

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2020年第2期8卷 276-283页

作者： Sabina Karim Ferdousi Begum Afiqul Islam Monowar Ahmad Tarafdar Mamtaz Begum md Johirul Islam Bushra Malik md shamim Ahsan Ameneh Khatami Harunor Rashid Department of Paediatric Haematology and Oncology National Institute of Cancer Research and HospitalMohakhaliDhaka 1212Bangladesh Department of Pediatric Hematology and Oncology Bangabandhu Sheikh Mujib Medical UniversityDhaka 1212Bangladesh Department of Community Medicine Z.H.Sikder Women’s Medical CollegeDhaka 1212Bangladesh Department of Cancer Epidemiology National Institute of Cancer Research and HospitalMohakhaliDhaka 1212Bangladesh National Centre for Immunisation Research and Surveillance The Children’s Hospital at WestmeadWestmeadNSW 2145Australia Medical Services Rangpur CantonmentRangpur 5400Bangladesh Department of Infectious Diseases and Microbiology The Children’s Hospital at WestmeadNSW 2145Australia Discipline of Child and Adolescent Health Faculty of Medicine and HealthUniversity of SydneyNSW 2145Australia

BACKGROUND Diarrhoea is a frequent symptom in children with cancer, and occurs due to a composite effect of underlying disease and immunosuppression consequent to therapy, malnutrition, and non-infective aetiologies such as mucositis. In a large proportion of cases, the aetiology of diarrhoea remains unknown but is often attributed to multiple pathogens including *** To identify and describe the pathogens causing diarrhoea in Bangladeshi children with *** Two cross-sectional pilot studies were conducted involving paediatric oncology patients with diarrhoea. Stool samples were collected from children who were hospitalised with or without being treated with chemotherapy during the study period, and had diarrhoea at any stage during their admission. In the first study,stool samples were tested by conventional microbiological methods and by polymerase chain reaction for parasites, and by immunoassays for Clostridium difficile. In the second study, conventional microbiology was conducted for bacteria and parasites including an enzyme-linked immunosorbent assay for Cryptosporidium antigen, and in a subset, immunoassays for Clostridium *** In the first study Giardia lamblia was detected in 68.5% of samples, Entamoeba histolytica in 13%, Cryptosporidium in 5.6%, non-toxigenic C. difficile in 22.4%, and other bacteria in 5.2%. In the second study, E. histolytica was detected in 10% of samples, Cryptosporidium in 4.3%, G. lamblia in 1.4%, C. difficile in 5.1%, and other bacteria in 5.7% of *** These pilot data suggest that parasites are important aetiologies of diarrhoea in Bangladeshi children with malignancy. While molecular diagnostic tools detect an array of stool pathogens with greater sensitivity, conventional diagnostic methods are also useful.

关键词： Bangladesh Cancer Child Cryptosporidium Gastroenteritis Parasite

Study of the structural and electrical behavior of Bi(Mg,Ti)O_(3)modified(Ba,Ca)TiO_(3)ceramics

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 Advanced Dielectrics 2016年第4期6卷 72-80页

作者： md.Kashif shamim Seema Sharma Arpana Singh Radheshyam Rai Rashmi Rani Ferroelectric Research Laboratory Department of Physics A.N.CollegePatna 800013India School of Physics and Materials Science Shoolini University SolanHimachal PradeshIndia

The ability of BaTiO_(3)to form solid solutions with different dopants(both iso-and aliovalent)makes it versatile for various *** the present study,(Ba,Ca)TiO_(3)(BCT)is modified with Bi(MgTi)O_(3)(BMT)in search for new lead-free ferroelectric material and improve their *** this purpose,BCT acts as a main base material and BMT acts as a modifier to fabricate a multifunctional *** this study,we report the structural and electrical properties of lead free piezo-ceramics(1-x)(Ba_(0.8)Ca_(0.2))TiO_(3–x)Bi(Mg_(0.5)Ti_(0.5))O_(3)with x=0.2,0.4,0.5 prepared by solid-state sintering *** perovskite phase with tetragonal structure is obtained for all the compositions,which is reconfirmed by the Raman Spectroscopic *** study confirm the temperature stable behavior of the dielectric permittivity values above 300℃.The dielectric constant value decreases with increase in BMT doping *** Spectroscopic study confirms non-Debye type dielectric relaxation in the *** Nyquist plot and conductivity studies show the negative temperature coefficient of resistance behavior(NTCR)of the samples.

关键词： Perovskite Raman analysis non-Debye type XRD ferroelectrics.

Current Status of Conventional and Molecular Interventions for Blast Resistance in Rice

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Rice science 2017年第6期24卷 299-321页

作者： Deepti SRIVASTAVA md shamim Mahesh KUMAR Anurag MISHRA Pramila PANDEY Deepak KUMAR Prashant YADAV Mohammed Harrish SIDDIQUI Kapildeo Narayan SINGH Integral Institute of Agricultural Science and Technology Integral University Lucknow 226021 India Department of Molecular Biology and Genetic Engineering Dr. Kalam Agricultural College Bihar Agricultural University Sabour Bhagalpur Bihar 813210India Department of Agriculture Biotechnology Sardar Vallabhbhai Patel University of Agriculture and Technology Modipuram Meerut 250110 India Department of Plant Molecular Biology and Genetic Engineering Narendra Deva University of Agriculture and Technology Kumarganj Faizabad 224229 India Indian Council of Agricultural Research Directerate of Rapeseed mustard Research Bharatpur Rajasthan 321303 India

Pyricularia oryzae anamorph of Magnaporthe oryzae is one of the most notorious fungal pathogens causing severe economic loss in rice production worldwide. Various methods, viz. cultural, biological and molecular approaches, are utilized to counteract this pathogen. Moreover, some tolerant or resistant rice varieties have been developed with the help of breeding programmes. Isolation and molecular characterization of different blast resistance genes now open the gate for new possibilities to elucidate the actual allelic variants of these genes via various molecular breeding and transgenic approaches. However, the behavioral pattern of this fungus breakups the resistance barriers in the resistant or tolerant rice varieties. This host-pathogen barrier will be possibly countered in future research by comparative genomics data from available genome sequence data of rice and M. oryzae for durable resistance. Present review emphasized fascinating recent updates, new molecular breeding approaches, transgenic and genomics approaches(i.e. mi RNA and genome editing) for the management of blast disease in rice. The updated information will be helpful for the durable, resistance breeding programme in rice against blast pathogen.

关键词： backcross breeding gene pyramiding allele mining transgenic technology rice blast resistance CRISPR/Cas9 molecular breeding bioinformatics approach