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Performance comparison of zero-Schottky-barrier and doped contacts carbon nanotube transistors with strain applied

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Nano-Micro Letters 2010年第2期2卷 126-133页

作者： Md.Abdul Wahab khairul alam Department of Electrical and Electronic Engineering United International University Department of Electrical and Electronic Engineering East West University

Atomistic quantum simulation is performed to compare the performance of zero-Schottky-barrier and doped source-drain contacts carbon nanotube field effect transistors(CNTFETs) with strain applied. The doped source-drain contact CNTFETs outperform the Schottky contact devices with and without strain applied. The off-state current in both types of contact is similar with and without strain applied. This is because both types of contact offer very similar potential barrier in off-state. However, the on-state current in doped contact devices is much higher due to better modulation of on-state potential profile, and its variation with strain is sensitive to the device contact type. The on/off current ratio and the inverse subthreshold slope are better with doped source-drain contact, and their variations with strain are relatively less sensitive to the device contact type. The channel transconductance and device switching performance are much better with doped source-drain contact, and their variations with strain are sensitive to device contact type.

关键词： Zero-Schottky-barrier Doped contact Strain Inverse subthreshold slope Intrinsic cut-off frequency

Implementation of Efficient B2G and V2G in Practical Cases

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Journal of Electronic Science and Technology 2018年第4期16卷 325-340页

作者： MD Shahrukh Adnan Khan Kazi Mahtab Kadir Md.Ibrahim Ibne alam Md.khairul alam Jianhui Wong Aseef Iqbal University of Asia Pacific Dhaka 1205 Bangladesh Department of Electrical and Electronic Engineering Universiti Tunku Abdul Rahman Kampar 31900Malaysia Chittagong Independent University Chittagong Bangladesh

In this paper, building to grid(B2G) and vehicle to grid(V2G) have been defined with clear and practical understanding. Both of them are new generation technologies which are the essential part of smart city living and crowd energy clustering. Firstly, an in-detailed overview has been provided with an introduction to B2G and V2G followed by a historical overview and theoretical analysis in respect to smart city planning. Next, a review is conducted on current and previous smart living research, which deals with B2G and V2G. Efficient B2G and V2G implementations in practical cases then have been discussed. Lastly, both of these technical prospects have been analyzed in crowd energy diagram.

关键词： Building to grid(B2G) crowd energy practical implementation smart city living vehicle to grid(V2G)

Optimization of Heat Spreader Design for Electronic Cooling

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Computer Technology and Application 2013年第2期4卷 105-110页

作者： khairul alam Xiaoping Shen Rahat Taposh The Department of Mechanical Engineering Ohio University Athens OH 45701 USA The Department of Mathematics Ohio University Athens 0H45701 USA

The continuing increase in IC （Integrated Circuit） power levels and microelectronics packaging densities has resulted in the need for detailed considerations of the heat sink design for integrated circuits. One of the major components in the heat sink is the heat spreader which must be designed to effectively conduct the heat dissipated from the chip to a system of fins or extended surfaces for convective heat transfer to a flow of coolant. The heat spreader design must provide the capability to dissipate the thermal energy generated by the chip. However, the design of the heat spreader is also dependent on the convection characteristics of the fins within the heat sink, as well the material and geometry of the heat spreader. This paper focuses on the optimization of heat spreaders in a heat sink for safe and efficient performance of electronic circuits. The results of the study show that, for air-cooled electronics, the convective effects may dominate the thermal transport performance of the heat spreader in the heat sink.

关键词： Electronic cooling heat spreader optimum dimension.

Energy Harvesting——Technical Analysis of Evolution,Control Strategies,and Future Aspects

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Journal of Electronic Science and Technology 2019年第2期17卷 116-125页

作者： MD. Shahrukh Adnan Khan Md. Tanbhir Hoq A. H. M. Zadidul Karim Md. khairul alam Masum HowladerRajkumar Rajprasad Kumar School of Science and Engineering Canadian University of Bangladesh Dhaka 1213 Bangladesh Department of Electrical and Electronic Engineering University of Asia Pacific Dhaka 1215 Bangladesh Department of Electrical and Electronic Engineering University of Nottingham Malaysia Campus Semenyih 43500 Malaysia

This paper provides a technical analysis of energy harvesting (EH) in the field of power and energy sector, including different aspects of harvesting energy, individual case history, control strategies of harvesting in the field of power and energy sector together with the current trend and future aspects of it. EH is comparatively a new concept which is growing very fast since the 20th century and catching new generation research approaches. This paper not only describes the past and current scenarios of harvesting energy with radio frequency (RF) and renewables but also gives author’s own anticipation of the upcoming future trends of it by comparing the case histories.

关键词： Energy harvesting (EH) piezoelectric radio frequency (RF) solar triboelectric wind

Comparative regeneration status in a natural forest and enrichment plantations of Chittagong (south) forest division, Bangladesh

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Journal of Forestry Research 2004年第4期15卷 255-260页

作者： M. Kamal Hossain M. Lutfor Rahman A. T. M. Rafiqul Hoque M. khairul alam Institute of Forestry and Environmental Sciences University of Chittagong Chittagong-4331 Bangladesh Institute of Forestry and Environmental Sciences University of Chittagong Chittagong-4331 Bangladesh Institute of Forestry and Environmental Sciences University of Chittagong Chittagong-4331 Bangladesh Forest Botany Division Bangladesh Forest Research Institute Chittagong Bangladesh

The natural regeneration of the tree species in pure natural forest stand and enrichment plantations of Baraitali Forest of Chittagong (South) Forest Division, Bangladesh was studied by stratified random quadrat method during April 2002 to November 2002. Totally 100 plots of 3 m X 3 m in size represents a total of 64 regenerating tree species from natural forest with an average seedlings of 24767/hm2, while only 40 regenerating tree species were recorded from enrichment plan-tations with an average seedlings of 18633/hm2. Maximum regeneration in natural forest was found with Castanopsis spp. (2200 seedlings/hm2) followed by Glochidion lanceolarium (2183 /hm2) whereas, in enrichment plantations maximum regen-eration was found with Dipterocarpus gracilis (2117/hm2) followed by Anogeissus acuminata (2000/hm2). For natural forest, highest relative density was found for Castanopsis spp (8.88%), relative frequency for Glochidion lanceolarium (7.36%), rela-tive abundance for Syzygium spp. (3.79%) and Importance Value Index were recorded with Glochidion lanceolarium (18.24%). The corresponding values for enrichment plantations were highest with Dipterocarpus gracilis (11.36%), Glochidion lanceo-larium (9.71%), Dipterocarpus gracilis (5.92%), Glochidion lanceolarium (23.32%) respectively. Stem per hectare of some common trees with their seedlings and saplings in both the natural stands and enrichment plantations showed that only Dip-terocarpus gracilis successfully recruited in both sites but recruitment was higher in natural forest. Like many other primary rain forests, the Baraitoli forest typically has both substantial seedlings and soil seed bank from which regeneration may occur. The naturally regenerated seedlings are quite dense but it could not reach the pole stage due to human interference.

关键词： Regeneration Natural forest Enrichment plantations Relative density Frequency Abundance Importance Value Index

Preparation and Properties of Indium Selenide （InSe） Thin Films for Selective Surface Applications

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Journal of Physical Science and Application 2011年第1期1卷 37-43页

作者： Jaker Hossain Md. Julkamain Kazi Shaifullah Sharif khairul alam Khan Department of Applied Physics ＆ Electronic Engineering University of Rajshahi Rajshahi 6205 Bangladesh

Indium selenide （InSe） thin films have been prepared by e-beam technique onto glass substrate at a pressure of-8 × 10^-5 Pa. The deposition rate of the InSe thin films is -8.30 nms^-1. InSe samples grown at room temperature have been termed as virgin, whereas the films at which the transition in electrical conductivity is shown to exhibit at a temperature of 415 to 455 K have been termed as phase-transited samples. X-ray diffraction （XRD） study reveals that lnSe thin films are amorphous in nature before phase-transition while they are polycrystalline after phase-transition. Scanning electron microscopy （SEM） has been used to study the surface morphology of InSe thin films. Before phase-transition grains are absent in the films and surfaces are almost smooth and uniform. Film surfaces are seen to exhibit a number of grains after phase-transition and they are rough in surfaces. The elemental composition of the lnSe thin films has been estimated by EDAX method. The effects of temperature on the electrical properties of InSe thin films have been studied in details. Temperature dependence of electrical conductivity shows a semiconducting behavior with activation energy. Thickness dependence of conductivity is well in conformity with the Fuchs-Sondheimer theory. Thermopower study indicates that the InSe film is an n-type semiconductor. The optical study of InSe thin films is carried out in the wavelength range 360 to 1100 nm at room temperature. The study of absorption coefficient of InSe thin films shows a direct type transition with a band gap of=1.65 eV which is well agreed with the reported values. Integrated values of luminous and solar transmittance as well as of reflectance have been calculated. Appreciable order of transmittance and reflectance suggest that this material is a potential candidate for the application in selective surface devices.

关键词： InSe thin films e-beam technique XRD SEM thermopower.

Traditional Use, Phytochemistry, Pharmacological and Toxicological Properties of Acanthus ilicifolius: A Review

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Journal of Biosciences and Medicines 2023年第5期11卷 181-192页

作者： Fatema Tuz Zohora A. H. M. Nazmul Hasan K. M. khairul alam Tania Binte Wahed Department of Pharmacy Faculty of Biological Sciences Jahangirnagar University Savar Dhaka Bangladesh Department of Pharmacy School of Medicine University of Asia Pacific Dhaka Bangladesh

The practice of plants for the deterrence and management of innumerable physiological states and diseases dates back to the history of humankind. Although many of today’s medicinal yields are achieved synthetically, they are often modelled on the chemical composition of medicinal plants. In this accordance, Acanthus genus (Family Acanthaceae) has acknowledged considerable attention due to its wide range of secondary metabolites and its customary usage in Indian and Chinese system of medicine. It is worth to mention that A. ilicifolius is enormously medicinal among all the species of Acanthus genus. This plant is considered to be rich sources of steroids, triterpenoids, saponins, flavonoids, alkaloids, and tannins. Traditionally, the plant has been used for asthma, diabetes, dyspepsia, hepatitis, leprosy, neuralgia, paralysis, ringworm, skin disease, snake bite, leukemia. Toxicological investigation in mice model has showed that, the ethanolic extract of the leaves of this plant have no toxic effect up to dose of 1000 mg/kg BW, 2000 mg/kg BW dose have mild toxicity and 5000 mg/kg BW dose have caused toxic effect in some organ system like liver, heart, pancreas, lung and kidney. Different extract of this plant also exhibited Anti-inflammatory, anti-leishmanial, osteoblastic, hepatoprotective, antioxidant and anticancer activities. This review article is an endeavor to cover current expansion in phytochemical and pharmacological potential of this plant species which will be a good reference tool for investigators who wish to work on natural products.

关键词： Acanthus Acanthaceae Acanthus ilicifolius Anti-Cancer Hepato-Protective Effect

Prospects and limitations of soil amendment and irrigation techniques for the water-saving public urban greenery and ephemeral weed management in the sandy soils of the United Arab Emirates

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Journal of Arid Land 2024年第9期16卷 1288-1302页

作者： Ayesha alam Elke GABRIEL-NEUMANN Department of Integrative Agriculture College of Agriculture and Veterinary MedicineUnited Arab Emirates UniversityAl Ain 15551the United Arab Emirates ASPIRE Research Institute of Food Security in Drylands College of Agriculture and Veterinary MedicineUnited Arab Emirates UniversityAl Ain 15551the United Arab Emirates

Public urban greenery greatly contributes to the residential and tourist value of cities in the Gulf Region,but due to the hyper-arid climatic conditions,the cost of irrigation and plant maintenance is very *** strategies to reduce the monetary and ecological costs involve the cultivation of native xerophytic plantations,and/or the use of soil improvers to increase water-and nutrient-holding capacity of the sandy *** soil improvers based on mineral,organic,or synthetic materials have entered the United Arab Emirates(UAE)market in recent years,but there is considerable uncertainty about how they should best be used in combination with ornamental plant stands involving xerophytic native *** present study investigated the effect of soil amendment and deep pipe irrigation on perennial ornamental plant stands involving native plants(Tephrosia appolinea(Gel.)Link in combination with Aerva javanica(Burm.f.)*** Schult.)and native-exotic plants(*** in combination with Ruelia simplex ***)either or not topsoil and subsoil amendment with bentonite and hydrophobic sand under the irrigation water supply of less than 50%of reference evapotranspiration(ET0).After one year of cultivation,*** and ***(native ***)produced high biomass and exhibited high water use efficiency(WUE)as compared with *** and ***(native ***)combination given that no significant differences were found under the soil amendment *** stands thrived under irrigation water supply far below what is usually supplied to exotic ornamental stands in public parks of the Al Ain City,the ***,subsoil amendment in combination with deep pipe irrigation reduced the occurrence of weeds and increased the overall plant rooting *** results suggest that subsoil amendment and irrigation up to 60-80 cm depth can potentially control ephemeral weed infestation,which is a great challenge in various plant production systems of the

关键词： native and exotic plant communities competitive strength soil improvers urban plantation subsoil amendment weed management

Effect of Tillage and Residue Retention on Soil Properties and Crop Yields in Wheat-Mungbean-Rice Crop Rotation under Subtropical Humid Climate

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Open Journal of Soil Science 2017年第1期7卷 1-17页

作者： Nazmus Salahin khairul alam Abu Taher Mohammad Anwarul Islam Mondol Mahammad Shariful Islam Md. Harunur Rashid Muhammad Azizal Hoque Soil Science Division Bangladesh Agricultural Research Institute (BARI) Gazipur Bangladesh Land Management Group School of Veterinary and Life Sciences Murdoch University Murdoch Australia On-Farm Research Division BARI Gazipur Bangladesh Department of Agricultural Extension MoA Dhaka Bangladesh

The effects of conservation agriculture (CA) practices on soil properties along with crop yields of rice-based triple cropping systems have not been adequately assessed in Bangladesh. An experiment was conducted at Bangladesh Agricultural Research Institute, Gazipur, Bangladesh from 2009 to 2012 to assess the effects of tillage practices and crop residue retention on soil physical properties, soil organic carbon (SOC) and crop yields in a wheat-mungbean-rice system. Treatments consisted of three tillage practices (MT: minimum tillage;CT: conventional tillage and DT: deep tillage) and eight levels of crop residue management (S0—no residues retention, Sr—retention of 30 cm rice straw, Sm—whole mungbean stover retention, SW—30 cm wheat straw retention, Smr—whole mungbean stover & 30 cm rice straw retention, Srw—30 cm rice & wheat straw retention, Smw—whole mungbean stover & 30 cm wheat straw retention and Swrm—30 cm wheat and rice straw along with whole mungbean stover retention) were applied in split plot design with three replications. Bulk density (BD) and porosity responded positively to MT and increased residue retention of all crops (p > 0.05). Minimum tillage and Swrm also significantly accumulated SOC (p < 0.05;0.38% higher than DT with no residue retention) and retained soil moisture (p < 0.05). Minimum tillage practice performed better in upland crops (p < 0.05;wheat & mungbean yields) and CT outperformed MT in wetland rice crop (p < 0.05). The grain and straw yields of wheat and rice were also influenced by previous crop residue retentions (p < 0.05). The results, therefore, suggested that increased residue retention with minimum tillage practices improved soil properties and yield of upland crops but with deeper tillage practices consistently maintained wetland rice production.

关键词： Cropping System Residue Retention Soil Moisture Soil Organic Carbon (SOC) Tillage Practices