70 research outputs found
Seasonal Variations of Major Anions in Water at Baro Haor of Kishoreganj, Bangladesh and Revealing The Suitability for Aquatic Resource Management
Haors are areas with sweet water that inhabits a large variety of fishes and other aquatic animals. The quality of water in haors affects the lives in haors and the deterioration of the quality of water due to different anthropogenic reasons may affect the total ecosystem of haors. The study was conducted to investigate the physicochemical parameters and major anions of water of Baro haor area in Kishoreganj during the period from September 2016 to August 2017. The water samples were collected monthly during the pre-monsoon (Feb. to May), monsoon (Jun. to Sep.) and post-monsoon (Oct. to Jan.) seasons from five sampling stations as: (i) Bayershuil beel (St-1), (ii) Tegulia beel (St-2), (iii) Singpur beel (St-3), (iv) Neora beel (St-4) and (v) Bara beel (St-5). The physicochemical water quality was analyzed in the laboratory of the Department of Environmental Science and Resource Management (ESRM), Mawlana Bhashani Science and Technology University (MBSTU), whereas, anions were analyzed in Bangladesh Institute of Nuclear Agriculture (BINA), Mymensingh. Results of the study showed that the mean temperature, electrical conductivity (EC), total dissolved solid (TDS), dissolved oxygen (DO), biochemical oxygen demand (BOD), pH, alkalinity and hardness were found 28.03°C, 696.70 µS/cm, 484.35 mg/L, 6.62 mg/L, 2.36 mg/L, 7.40, 291.35 mg/L and 106.85 mg/L, respectively which revealed that the water was suitable for aquatic environment as well as fish production. Mean concentration of fluoride (F-), chloride (Cl-), bromide (Br-), nitrite (NO2-), nitrate (NO3-) and sulfate (SO42-) were 0.35, 121.35, 0.15, 5.63, 28.41 and 66.29 mg/L, respectively. The water quality was found suitable for aquatic environment and for fish production but the haor area is highly subjected to anthropogenic disturbances. To conserve the aquatic environment of the Baro haor regular monitoring and management should be taken to maintain the water quality
Carbonaceous soil amendments to reduce plant uptake of Cd in NZ’s agricultural systems
Cadmium (Cd) is a non‐essential trace element that accumulates in agricultural soils through the application of Cd-rich phosphate fertiliser and industrial activity. Plants can accumulate Cd to concentrations that sometimes exceed food safety standards presenting a human health risk. Cadmium is readily taken up by plants and can be transferred to grazing animals. In many agricultural systems, Cd concentrations in leafy vegetables and the offal products of grazing animals are at or above food safety standards. There is no practical means of removing Cd from contaminated agricultural soils. Various soil amendments have been used to reduce plant Cd-uptake, but these have mostly focused on heavily contaminated soils and mine tailings. This work aimed to determine whether low cost carbonaceous amendments could effectively reduce Cd uptake by crop plants in agricultural soils with moderate levels of Cd contamination.
We used two contrasting market garden soils (a silt loam and a brown granular allophanic soil) for these experiments, where Cd concentrations in selected vegetables were occasionally above food safety standards (0.1 mg/kg fresh weight). Batch sorption experiments were used to determine the ability of the soils and potential soil amendments to bind Cd from a solution of 0.05M Ca(NO3)2. The sorption experiments revealed that composts and lignite bound an order of magnitude more Cd than soils and other potential soil amendments. For all materials, sorption increased with increasing pH of the ambient solution up to a pH of 7.5.
Pot trials were used to determine the effect of various composts, lignite and lime on the uptake of Cd by spinach (Spinacia oleracea L.), lettuce (Lactuca sativa L.), onion (Allium cepa L.) and potato (Solanum tuberosum L.). All composts, added at a rate of 2.5% or 5% (w/w) reduced plant Cd uptake by up to 60%. The composts did not induce a deficiency in the uptake of plant nutrients, including essential trace elements such as zinc, and copper. Composts invariably increased plant biomass.
An incubation experiment, including treatments with increased temperature and nitrogen as well as regular disturbance, was used to determine the likely longevity of the Cd-immobilising properties of the composts. After one year of incubation, there was no significant release of Cd from the compost-amended soils, despite a significant reduction in soil carbon. A pot trial using incubated soil also revealed that the beneficial effects of compost for reducing plant Cd uptake persisted for at least one year. The results indicated that mechanical disturbance of the soil may have resulted in the dissolution / suspension of iron moieties that subsequently occluded Cd on the surfaces of soil colloids.
Lignite generally reduced plant biomass and its effect on plant Cd-uptake was variable. In some cases, lignite caused a significant increase in plant Cd uptake. This was attributed to acidification, probably caused by oxidation of sulphide compounds in the lignite. Potentially, lignite-lime mixtures may be effective, however, the costs of lignite are significantly greater than composts. Using lime to increase the soil pH from 6.0 to 6.5 generally reduced the Cd concentration in soil solution and in vegetables. However, this effect was not consistent, with some treatments causing an increase in plant uptake. Moreover, liming significantly reduced the uptake of essential micronutrients, especially zinc, which offsets its usefulness as a tool to reduce Cd uptake.
I conclude that biological wastes, especially composts, are an underutilised resource that can not only reduce plant Cd-uptake but also improve plant production. Future research should include field trials to determine the performance of Cd in field conditions as well as agronomic practicalities
Detection of Chemical Change of Adsorbates using Electrical Property of MoS2 Field-Effect Transistor
Tohoku University博士(理学)博士学位論文 (Thesis(doctor))要約のみthesi
Assessment of Calamus tenuis fruits extract on blood glucose level elevation and its antibacterial potency
Investigation of anti-hyperglycemic and antibacterial activity of the fruit extract of Calamus tenuis was carried out. Soxhlet extraction was done using petroleum ether, ethyl acetate and methanol. Anti-hyperglycemic activity was done by Oral Glucose Tolerance Test.The results indicated that methanol extract (500 mg/Kg) showed nearly same potency of blood glucose lowering capacity (4.82 ± 0.730 mmol/L) compared to the glibenclamide (standard drug). Antibacterial activity was investigated using disc diffusion method. Antibacterial tests revealed that S. aureus was resistant to all the solvent extracts. Ethyl acetate and methanol extracts showed moderate antibacterial capacity against both Micrococcus and V. cholerea whereas petroleum ether showed nothing. Zone of inhibition of Ethyl acetate and methanol extracts (200 mg/mL dose) for E. coli were very close to positive control (17.00 ± 0.816 and 18.75 ± 1.258 mm respectively; positive control value was 19.00 ± 1.414 and 21.00 ± 1.414 respectively ). In case of methanol zone of inhibitions were greater than other solvent extracts against all tested bacterial species. From the present research it can be recapitulated that due to the biological activity of C. tenuis fruit it may satisfy as a new candidate for the emergence of medicines
Techno-financial analysis and design of on-board intelligent-assisting system for a hybrid solar–DEG-powered boat
COVID-19 Pandemic: A Comparative Prediction Using Machine Learning
Coronavirus Disease 2019 or COVID-19 is an infectious disease which is declared as a pandemic by the World Health Organization (WHO) have a noxious effect on the entire human civilization. Each and every day the number of infected people is going higher and higher and so the death toll. Many of country Italy, UK, USA was affected badly, yet since the identification of the first case, after a certain number of days, the scenario of infection rate has been reduced significantly. However, a country like Bangladesh couldn't keep the infection rate down. A number of algorithms have been proposed to forecast the scenario in terms of the number of infection, recovery and death toll. Here, in this work, we present a comprehensive comparison based on Machine Learning to predict the outbreak of COVID-19 in Bangladesh. Among Several Machine Learning algorithms, here we used Polynomial Regression (PR) and Multilayer Perception (MLP) and Long Short Term Memory (LSTM) algorithm and epidemiological model Susceptible, Infected and Recovered (SIR), projected comparative outcomes
ASSESSMENT OF WORKING ENVIRONMENT IN READY-MADE GARMENT INDUSTRIES: A CASE STUDY IN GAZIPUR, BANGLADESH
The study was conducted to assess the ambient environmental condition (temperature, humidity, noise and illumination) in the SIJI Garments Co. Ltd., Ehsan Garments Ltd. and Silver Composite Textile Mills Ltd. in Gazipur District, Bangladesh from September, 2016 to February, 2017 (during winter season) to know the internal working environment of the garment industries. In the SIJI Garments Co. Ltd., the highest temperature was observed in the cutting section (28.7°C), sewing section (28.9°C) and packaging section (29.2°C) which exceeded the guideline values. The highest noise level was observed in packaging section (86.6 dB). The illumination level in the most densely populated sections of workers such as cutting section (450 lux), sewing section (490 lux) and sample section (488 lux) were found unpleasant for the workers. In Ehsan Garments Ltd., the highest temperature was observed in sewing section (26.4°C) which exceeded the ASHRAE (American Society of Heating, Refrigerating and Air Conditioning Engineers)standard and the noise level in sewing section (88.4) which exceeded the ECR guidelines. In Silver Composite Textile Mills Ltd. the illumination level was poor in almost all sections specially cutting (466 lux), sewing (565 lux) and finishing (515 lux) sections where maximum number of workforce was employed. The temperature of all sections of three readymade garment industries were optimum to moderately high, humidity level was around optimum level but the noise levels highly exceeded the ECR, 1997. The illumination level was insufficient especially in the cutting and sewing section.The study revealed that congested work area, improper ventilation, building design, excessive noise, poor illumination, dust and no use of personal protective equipment were the major problem faced by the workers in these industries
Impact of Cyclone on Livelihood Pattern in the South Western Coastal Region of Bangladesh: Pirojpur
This research was carried out to assess the impact of cyclone on livelihood pattern in Pirojpur district, Bangladesh during January to June, 2017. The study was both qualitative and quantitative type. The primary data were collected using randomly sampling method (42+42+42=126 respondents) from Tushkhali, Bhitabaria and Pattashi villages of Pirojpur district. The secondary data were collected from different journals, articles, books, official documents, thesis papers and also daily newspapers etc. From the study it was observed that monthly income of middle (4001-8000 tk) and high (8001-above tk) income groups ware decreased by 5% and 0.92% respectively while low income people (1-4000 tk) was increased due to decrease of production after Sidr. On the other hand, expenditure ability of low and middle income groups was decreased. Sidr has created a great impact on human health, livestock, fisheries, food habit, crop production and occupation pattern of the affected people. Respondent’s houses were damaged partially (66.78%), 33.22% completely and cultivated land 28.57 % completely by Sidr in study area. Respondents of the study area said that the production of rice (8%), chili (12%), and vegetables (11%) were reduced due to saline water entrance into the crop field after Sidr. Affected people were migrated (temporary 23.10%, local 25% and internal 26.10%) from Pirojpur to Dhaka (53%), Pirojpur to other places (47%) on the post Sidr due to loss of houses, shelters, cultivated land and lack of job opportunity. Among all factors of temporary migration, water logging was the first reason of migrating people of the study area.
Source of Cadmium (Cd) In Soils and Its Transfer to Rice and Vegetables: Karotia Union, Tangail
Cadmium is a trace element which is not essential for human being. High cadmium concentration in some rice samples in Bangladesh was reported than that of other countries. This study was carried out to find out the Cd concentration fertilizers, soils, rice and vegetables and along with other chemical properties of Karotia union, Tangail sadar upazila, Tangail. A total of 29 samples were collected among the 14 soils from 7 stations at 0-15 cm and 16-30 cm depth respectively, 5 vegetables, 5 rice and also 4 different countries TSP fertilizers from local market. The Cd concentration values of all soil samples were found between 0.97 to 1.73 mg/kg (0-15 cm) and 0.53 to 0.83 mg/kg (16-30 cm), respectively and the vegetable sample values were found between 0.053 mg/kg to 0.123 mg/kg (d.w.).The rice sample values were found between 0.05 mg/kg to 0.096 mg/kg (d.w.). The fertilizer sample values were found between 20.67 to 92.33 mg/kg. The soil pH values obtained 7.06 to 7.70 (0-15 cm) and 7.48 to 7.88 (16-30 cm) which indicated that the study area soils were neutral to moderately alkaline. The EC values of all soil samples were between 47.67 to 82.67dSm-1 (0-15cm) and 33.33 to 58.33dSm-1 (16-30 cm). The organic matter content of all soils ranged from 0.789 to 0.905% and 0.351 to 0.869% at (0-15 cm and 16-30 cm), respectively. The available sodium (Na) values of soils were found between 1.84 to 1.92 ppm (0-15 cm) and 1.83 to 1.90 ppm (16-30 cm), respectively. The available potassium values ranged from 1.81 to 1.96 ppm (0-15 cm) and 1.84 to 1.97 ppm (16-30cm), respectively. The available calcium values of all soil samples were 1.92 to 1.97 ppm (0-15 cm) and 1.91 to 1.96 ppm (16-30 cm), respectively.
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