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Effects of shifting cultivation on biological and biochemical characteristics of soil microorganisms in Khagrachari hill district, Bangladesh

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Journal of Forestry Research 2014年第3期25卷 689-694页

作者： sohag miah S.M. Sirajul Haque Wahida Sumi Mohammad Mosharraf Hossain Institute of Forestry and Environmental Sciences University of Chittagong Department of Microbiology University of Chittagong Department of Applied Physics Graduate School of Engineering Osaka University

We collected soil samples from two representative sites at Aatmile of Khagarachari hill district in Chittagong Hill Tracts. One of the sites was under shifting cultivation and the other an adjacent 13-year old teak plantation. Both sites were in the same physiographic condition and same aspect with parable soil type, which enabled us to measure the effects of shifting cultivation on soil micro-flora. We studied soil phys-ico-chemical properties and the biochemical and biological properties of soil microbes. Moisture and organic matter content as well as fungi and bacterial populations, both in surface and subsurface soils, were signifi-cantly （p≤0.001） lower in shifting cultivated soils compared to soils not under shifting cultivation, i.e. the teak plantation site. The most abundant bacteria in surface （0-10 cm） and sub-surface （10-20 cm） soils under shifting cultivation were Pseudomonas diminuta and Shigella, respec-tively, while in corresponding soil layers of teak plantation, predominant microbes were Bacillus firmus （0-10 cm） and Xanthomonas （10-20 cm）. The microbial population differences cannot be explained by soil texture differences because of the textural similarity in soils from the two sites but could be related to the significantly lower moisture and organic mat-ter contents in soils under shifting cultivation.

关键词： shifting cultivation soil biological properties soil biochemical properties soil microflora Chittagong Hill Tracts

Effect of shifting cultivation on soil physical and chemical properties in Bandarban hill district, Bangladesh

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Journal of Forestry Research 2013年第4期24卷 791-795页

作者： Khandakar Showkat Osman M.Jashimuddin S.M.Sirajul Haque sohag miah Institute of Forestry and Environmental Sciences University of Chittagong

This study reports the effects of shifting cultivation at slashing stage on soil physicochemical properties at Bandarban Sadar Upazila in Chittagong Hill Tracts of Bangladesh. At this initial stage of shifting cultivation no general trend was found for moisture content, maximum water holding capacity, field capacity, dry and moist bulk density, parti- cle density for some chemical properties between shifting cultivated land and forest having similar soil texture. Organic matter was significantly 0.05） lower in 1-year and 3-year shifting cultivated lands and higher in 2-year shifting cultivation than in adjacent natural forest. Significant differences were also found for total N, exchangeable Ca, Mg and K and in CEC as well as for available P. Slashed area showed higher soil pH. Deterioration in land quality starts from burning of slashing materials and continues through subsequent stages of shifting cultivation.

关键词： Chittagong Hill Tracts natural forest shifting cultivation soil properties

Clear felling and burning effects on soil nitrogen transforming bacteria and actinomycetes population in Chittagong University campus, Bangladesh

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Journal of Forestry Research 2012年第1期23卷 123-130页

作者： S.M. Sirajul Haque Rahima Ferdoshi sohag miah M. Nural Anwar Institute of Forestry and Environmental Sciences University of Chittagong Chittagong-4331 Bangladesh Department of Microbiology University of Chittagong Chittagong-4331 Bangladesh

The effect of forests clear felling and associated burning on the population of soil nitrogen transforming bacteria and actinomycetes are reported at three pair sites of Chittagong University campus, Bangla- desh in monsoon tropical climate. Clear felled area or burnt site and 15-21 year mixed plantation of native and exotic species, situated side by side on low hill having Typic Dystrochrepts soil was represented at each pair site. At all the three pair sites, clear felled area or burnt site showed very significantly （p~_0.001） lower population of actinomycetes, Rhizobium, Nitrosomonas, Nitrobacter and ammonifying as well as deni- trifying bacteria compared to their adjacent mixed plantation. From en- vironmental consideration, this finding has implication in managing natural ecosystem.

关键词： Nitrogen transforming bacteria actinomycetes forest clearfelling effects burning effects soil microorganisms Chittagong HillTracts

Shifting cultivation effects on creek water quality around Barkal Upazila in Chittagong Hill Tracts,Bangladesh

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Journal of Forestry Research 2012年第4期23卷 623-630页

作者： Shyamal Karmakar S.M.Sirajul Haque M.Mozaffar Hossain sohag miah Institute of Forestry and Environmental Sciences University of ChittagongChittagong 4331Bangladesh

Abstract： We report the effects of shifting cultivation on water quality in 16 creeks investigated once in 2007 and twice in 2008 in 16 apparently similar small neighboring watersheds, each of 3 to 5 ha, at four locations around Barkal sub-district under Rangamati District of Chittagong Hill Tracts in Bangladesh. Concentrations of 5042- and K＋, and pH in creek water were lower, and NO3-N and Na＋ concentrations were higher in shifting-cultivation land compared to land with either plantation or natu- ral forest or a combination of these cover types. Shifting cultivation effects on some water quality parameters were not significant due to change in land cover of the watershed between two sampling periods either through introduction of planted tree species or naturally regenerated vegetation. Conductivity and concentrations of HCO3- PO43-, Ca2-- and Mg2＋ in creek water showed no definite trend between shifting cultivation and the other land cover types. At one area near the Forest Range Office of Barkal, creek water pH was 5.8 under land cover with a com- bination of shifting cultivation and plantation. At this area Na~ concentra- tion in shitting-cultivation land ranged from 32.33 to 33.00 mg-L＂ and in vegetated area from 25.00 to 30.50 mg.L-1 in 2007. At another area, Chaliatali Chara, SO42 concentration in a shifting-cultivation watershed ranged from 4.46 to 10.51 mg-L-1, lower than in a vegetated watershed that ranged from 11.69 to 19.98 mg.L-1 in 2007. S042-concentration in this shifting-cultivation area ranged from 1.28 to 1.37 mg.L^-1 and in the vegetated area from 1.37 to 3.50 mg-L^-1 in 2008.

关键词： Shifting cultivation Creek water quality Chittagong Hill Tracts Riparian vegetation Land cover Bangladesh

Shifting cultivation effects on soil fungi and bacterial population in Chittagong Hill Tracts, Bangladesh

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Journal of Forestry Research 2010年第3期21卷 311-318,397页

作者： sohag miah Soma Dey S.M.Sirajul Haque Institute of Forestry and Environmental Sciences University of Chittagong

A study was conducted at two pair sites of Chittagong Hill Tracts in Bangladesh to find out the effects of shifting cultivation on soil fungi and bacterial population. The first pair of sites with shifting culti-vation and village common forest-managed by indigenous community was at Madhya Para in Rangamati district and the second pair of sites with the shifting cultivated land and village common forest at Ampu Para in Bandarban district of Chittagong Hill Tracts. At both the locations with two different land uses, soil textures in surface （0？10 cm） and sub-surface （10？20 cm） soils varied from sandy loam to sandy clay loam. Soil pH and moisture content were lower in shifting cultivated land com-pared to village common forest. The results also showed that both fungal and bacterial population in surface and subsurface soils was significantly （p ≤ 0.05） lower, in most cases, in shifting cultivated land compared to village common forest at both Madhya Para and Ampu Para. At Ranga-mati and Bandarban in shifting cultivated lands, Colletrotrichum and Fusarium fungi were absent and all the bacterial genus viz. Coccus, Bacillus and Streptococcus common in two different locations with dif-ferent land uses. Common identified fungi at both the land uses and locations were Aspergillus, Rhizopus, Trichoderma and Penicillium. Further study can be done on the other soil biota to understand the extent of environmental deterioration due to shifting cultivation.

关键词： shifting cultivation fungi bacteria soil biological properties village common forest Chittagong Hill Tracts Bangladesh

Surface-modified Ag@Ru-P25 for photocatalytic CO_(2) conversion with high selectivity over CH_(4) formation at the solid–gas interface

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Carbon Energy 2024年第1期6卷 182-196页

作者： Chaitanya B.Hiragond sohag Biswas Niket SPowar Junho Lee Eunhee Gong Hwapyong Kim Hong Soo Kim Jin-Woo Jung Chang-Hee Cho Bryan M.Wong Su-Il In Department of Energy Science&Engineering Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea Department of Chemical&Environmental Engineering Materials Science&Engineering ProgramDepartment of ChemistryDepartment of Physics&AstronomyUniversity of California-RiversideRiversideCaliforniaUSA Department of Physics and Chemistry Daegu Gyeongbuk Institute of Science and Technology(DGIST)DaeguRepublic of Korea NiceScience Corporation DaeguRepublic of Korea

Systematic optimization of the photocatalyst and investigation of the role of each component is important to maximizing catalytic activity and comprehending the photocatalytic conversion of CO_(2) reduction to solar fuels.A surface-modified Ag@Ru-P25 photocatalyst with H_(2)O_(2) treatment was designed in this study to convert CO_(2) and H_(2)O vapor into highly selective *** doping followed by Ag nanoparticles(NPs)cocatalyst deposition on P25(TiO_(2))enhances visible light absorption and charge separation,whereas H_(2)O_(2) treatment modifies the surface of the photocatalyst with hydroxyl(–OH)groups and promotes CO_(2) ***-resonance transmission electron microscopy,X-ray photoelectron spectroscopy,X-ray absorption near-edge structure,and extended X-ray absorption fine structure techniques were used to analyze the surface and chemical composition of the photocatalyst,while thermogravimetric analysis,CO_(2) adsorption isotherm,and temperature programmed desorption study were performed to examine the significance of H_(2)O_(2) treatment in increasing CO_(2) reduction *** optimized Ag1.0@Ru1.0-P25 photocatalyst performed excellent CO_(2) reduction activity into CO,CH4,and C2H6 with a~95%selectivity of CH4,where the activity was~135 times higher than that of pristine TiO_(2)(P25).For the first time,this work explored the effect of H_(2)O_(2) treatment on the photocatalyst that dramatically increases CO_(2) reduction activity.

关键词： gas-phase CO_(2) reduction H_(2)O_(2) treatment plasmonic nanoparticles solar fuel photocatalyst surface modification

Controlling hyperchaotic complex systems with unknown parameters based on adaptive passive method

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Chinese Physics B 2013年第6期22卷 268-276页

作者： Gamal M.Mahmoud Emad E.Mahmoud Ayman A.Arafa Department of Mathematics Faculty of ScienceTaibah UniversityAl-Madeenah Al-MunawwarahP.O.Box 344Kingdom of Saudi Arabia Department of Mathematics Faculty of ScienceSohag UniversitySohag 82524Egypt College of Applied Medical Sciences TurabahTaif UniversityKingdom of Saudi Arabia

The aim of this paper is to study the control of hyperchaofic complex nonlinear systems with unknown parameters using passive control theory. An approach is stated to design the passive controller and estimate the unknown parameters based on the property of the passive system. The feasibility and effectiveness of the proposed approach is demonstrated through its application to the hyperchaotic complex Lu system, as an example. The estimated values of the unknown parameters are calculated. The analytical form of the complex controller is derived and used in the numerical simulation to control the hyperchaotic attractors of this example. Block diagrams of this example using Matlab/Simulink are constructed after and before the control to ensure the validity of the analytical results. Other examples of hyperchaotic complex nonlinear systems can be similarly treated.

关键词： control passive control hyperchaotic complex

双液滴连续撞击高温壁面的SPH-ASR模拟研究

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中国科学：物理学、力学、天文学 2022年第10期52卷 33-45页

作者：李林豪杨秀峰 sohag Md M.A. 王晓亮刘青泉北京理工大学宇航学院北京100081

基于自适应分辨率光滑粒子法(Smoothed Particle Hydrodynamics with Adaptive Spatial Resolution,SPHASR),引入流体组分方程和相变模型,发展了一种能够模拟液体蒸发及蒸气扩散的多相流模拟方法,并应用该方法模拟研究了两个液滴连续撞... 详细信息

基于自适应分辨率光滑粒子法(Smoothed Particle Hydrodynamics with Adaptive Spatial Resolution,SPHASR),引入流体组分方程和相变模型,发展了一种能够模拟液体蒸发及蒸气扩散的多相流模拟方法,并应用该方法模拟研究了两个液滴连续撞击高温固体壁面问题.通过对比数值模拟与实验结果,验证了数值方法的有效性.在不同液滴直径、撞击速度、壁面温度和壁面倾斜角等条件下,对两个液滴连续撞击壁面过程进行了一系列数值模拟研究,获得了多种典型的撞击模式,包括铺展、破碎、单侧单次飞溅、单侧两次飞溅、两侧飞溅、融合反弹、分别反弹和膜态飞溅等.数值结果表明,撞击模式与壁面温度、壁面倾角、韦伯数和雷诺数相关.根据不同参数对撞击模式的影响,获得了不同的撞击相图.利用数据拟合获得了飞溅模式的临界韦伯数随壁面倾角的线性变化关系.

关键词：液滴撞击高温壁面多相流光滑粒子法自适应分辨率

Crop Improvement and Abiotic Stress Tolerance Promoted by Moringa Leaf Extract

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Phyton-International Journal of Experimental Botany 2022年第8期91卷 1557-1583页

作者： Md.Abir Ul Islam Juthy Abedin Nupur Charles T.Hunter Abdullah Al Mamun sohag Ashaduzzaman Sagar Md.Sazzad Hossain Mona F.A.Dawood Arafat Abdel Hamed Abdel Latef Marián Brestič Md.Tahjib-UI-Arif Department of Genetics and Plant Breeding Bangladesh Agricultural UniversityMymensingh2202Bangladesh Department of Agricultural Food and Nutritional ScienceUniversity of AlbertaEdmontonAB T6G 2R3Canada Chemistry Research Unit United States Department of Agriculture-Agricultural Research ServiceGainesville32608USA Department of Biochemistry&Molecular Biology Bangladesh Agricultural UniversityMymensingh2202Bangladesh Department of Crop Botany Bangladesh Agricultural UniversityMymensingh2202Bangladesh Department of Agronomy and Haor Agriculture Sylhet Agricultural UniversitySylhet3100Bangladesh Botany and Microbiology Department Faculty of ScienceAssiut UniversityAssiut71516Egypt Botany and Microbiology Department Faculty of ScienceSouth Valley UniversityQena83523Egypt Department of Botany and Plant Physiology Czech University of Life Sciences PraguePrague16500Czech Republic Institute of Plant and Environmental Sciences Faculty of Agrobiology and Food ResourcesSlovak University of AgricultureNitra94976Slovakia

Moringa leaf extract(MLE)has been shown to promote beneficial outcomes in animals and *** is rich in amino acids,antioxidants,phytohormones,minerals,and many other bioactive compounds with nutritional and growth-promoting *** reports indicated that MLE improved abiotic stress tolerance in *** understanding of the mechanisms underlying MLE-mediated abiotic stress tolerance remains *** review summarizes the existing literature on the role of MLE in promoting plant abiotic stress acclimation *** is applied to plants in a variety of ways,including foliar spray,rooting media,and seed *** application of MLE promoted crop plant growth,photosynthesis,and yield under both nonstress and abiotic stress *** treatment reduced the severity of osmotic and oxidative stress in plants by regulating osmolyte accumulation,antioxidant synthesis,and secondary *** also improves mineral homeostasis in the presence of abiotic ***,this review describes the potential mechanisms underpinning MLEmediated stress tolerance.

关键词： Abiotic stress antioxidants biostimulant plant growth moringa extract osmotic stress oxidative stress