Observation on some of the environmental parameters and feed quality of selected golda (Macrobrachium rosenbergii) farms in Bangladesh

A study was conducted to ascertain the existing farm water, effluent and feed quality of selected giant freshwater prawn farms from major prawn farming areas (Bagerhat Sadar, Noakhali Sadar and Mymensingh) of Bangladesh during July to November 2005. Water quality parameters such as the mean values of dissolved oxygen, alkalinity, nitrite-nitrogen, phosphate-phosphorus and ammoniacal nitrogen did not show any significantly differences among the farming areas. Whereas significant differences (p < 0.05) were observed in the mean values of temperature, secchi disc visibility, pH and chlorophyll a. However, all the water quality parameters in the farming areas were within the suitable range for prawn culture. There was no significant variation in nutrients concentration of discharged effluent among the prawn farming areas. All of the nutrients measured in effluent water were within the acceptable range and did not seem to pose a direct threat to the recipient environment. The analysed crude protein contents of commercial CP, Quality and Saudi-Bangla prawn feeds were 31.84%, 27.21% and 28.97%, respectively, whereas all analysed farm made feeds were less than 25%. The other nutrients of prawn feeds varied largely with the source of feeds and ingredients used to prepare feed. The annual yield of prawn varied from 320.4 to 512.6 kg/ha (mean 412.3 kg/ha) depending on the management system

General and advanced diagnostic tools to detect Mycobacterium tuberculosis and their drug susceptibility: a review

Contains fulltext : 155340.pdf (publisher's version ) (Closed access)The global control of tuberculosis remains a great challenge from the standpoint of diagnosis, detection of drug resistance, and treatment, because treatment can only be initiated when infection is detected, and is guided by the results of antimicrobial susceptibility testing. To a large extent, non-molecular, immunological, and other biochemical methods are refinements or modifications of conventional methods, with the primary goal of providing more rapid test results. In contrast, molecular methods use novel technologies to detect the presence of Mycobacterium tuberculosis complex and genes conferring drug resistance. As a group, molecular technologies offer the greatest potential for laboratories in resource-rich countries because they have the highest sensitivity and specificity. In resource-poor settings, continued development of affordable, sensitive, and specific diagnostic tools will be required, where the incidence of disease is highest

Cooling of air using heptadecane phase change material in shell and tube arrangement: Analytical and experimental study

A shell and tube latent heat storage (LHS) system using heptadecane with melting point 22.33 degrees C for active cooling of air has been analyzed analytically and experimentally in this paper. A theoretical model of laminar forced convection with varying wall temperature due to phase change material (PCM) outside a double wall circular tube and air as heat transfer fluid (HTF) inside a tube was employed to analyze active cooling of air. The analytical prediction in terms of outlet temperature was validated with experimental data. Furthermore, influences of some important design parameters (e.g. inner radius and thickness of the tube) on cooling effect were investigated. It was found that an optimum inner radius and thickness of the tube should be considered to design an LHS system. Better co-efficient of performance (COP) was observed for higher inlet air temperature while the outlet air temperature was almost identical. In this study, the COP of cooling was found 4.16 for 34.5 degrees C inlet air temperature using tube with 5.35 mm inner radius and 1 mm thickness. Some important thermophysical properties of heptadecane e.g. specific heat, thermal conductivity and density at liquid state were also examined and found 2.66 kJ kg(-1) K-1, 0.151 W m(-1) K-1 and 774 kg m(-3), respectively. (C) 2014 Elsevier B.V. All rights reserved

Fungal disease of freshwater fishes in Natore district of Bangladesh

An investigation was conducted on fungal disease of freshwater fishes in Natore district of Bangladesh from September 2005 to February 2006. A total of 2097 fish specimens where about 300 fishes under 15 fish species (8 culturable and 7 non culturable) were infected with fungal disease. Among culturable species most fungal infected fishes was C. mrigala (24.71%) where the total length, total weight and group of this infected fish was 10.8 to 40 cm, 10 to 995 g and 10.1 to 15 cm respectively followed by C. idellus (16.28%) and L. rohita (13.43%). Among non culturable species the most fungal infected fish was C. punctatus (22.42%) where the total length, total weight and group of this infected fish was 11 to 23 cm, 15 to 20 g and 20.1 to 25 cm respectively followed by C. striatus (16.88%) and P. ticto (15.31%). Disease in culturable fish species was less (13.40%) than non-culturable species (15.19%). Three genera of fungi were identified where Branchiomyces sp. was associated with gill rot disease and Saprolegnia sp. and Aphanomyces sp. were associated with ulcer types of disease. The incidence (%) of disease was highest in the month of December (22.49%) followed by November (20.25%) and January (18.00%)

Curbing global warming with phase change materials for energy storage

The application of thermal energy storage (TES) system with phase change material (PCM) is an effective way for energy conservation and greenhouse gas (GHG) emission reduction. Global warming is increasing along with the energy consumption. Many researchers are concerned about this present global environmental problem for fossil-fuel burning. Thermal energy storage system with phase change material is observed as a potential candidate for mitigating this problem. This paper emphasizes the opportunities for energy savings and greenhouse-gas emissions reduction with the implementation of PCM in TES systems. For instance, about 3.43 of CO 2 emission by 2020 could be reduced through the application of PCM in building and solar thermal power systems. Similarly, energy conservation and GHGs emission reduction by other PCM applications for thermal comfort of vehicles, transport refrigeration, engine cold start, greenhouse and waste heat management are also presented. In addition, some present investigations on the performance improvement of the phase change materials are addressed

Synthesis of Mn3O4 nanoparticles via a facile gel formation route and study of their phase and structural transformation with distinct surface morphology upon heat treatment

Mn3O4 nanoparticles (NPs) were synthesized from the reduction of KMnO4 with glycerol at 80 °C in aqueous media via a gel formation route. In order to investigate the thermal stability and phase transformation, Mn3O4 NPs were subjected to heat treatment from 200 °C to 700 °C. The formation of different MnOx species observed by X-ray diffraction (XRD) measurements showed temperature dependent phase transformation occurring during the heat treatment process. XRD patterns showed that Mn3O4 NPs were formed at a temperature of 80 °C and two new phases Mn5O8 and Mn2O3 were appeared at 350 °C and 700 °C respectively. The three different oxides having their distinct surface morphologies viz., spherical, rod and cube shape respectively, were observed. Detailed morphological and structural investigations using Field Emission Scanning Electron Microscopy (FESEM), XRD, Thermo Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC) revealed the temperature dependent phases, crystal structures, lattice constants, particle sizes and surface morphologies of the MnOx species