A practical biogas based energy neutral home system for rural communities of Bangladesh

Growing demand of energy consumption, subsequent increase in energy generation costs, and increased greenhouse gas(GHG) emissions, as well as global warming from the conventional energy sources, encourages interest worldwide to bring a higher percentage of renewable energy sources such as biogas into the energy mix to build a climate friendly environment for the future. Moreover, due to high investment and maintenance costs, governments are not providing enough support for grid extension and delivering electricity to remote locations or rural areas, in particular, in under-developing countries like Bangladesh. Therefore, this paper presents an Energy Neutral Home System (ENHS) that can meet all its energy requirements from low-cost, locally available, nonpolluting biogas generated from animal waste, in particular, chicken and cow manure. The proposed ENHS has been developed for rural community, typically an area of 200 families, and will not only provide cooking gas and sustainable and affordable power supply to the community with low emissions, but will also facilitate high quality fertilizer for agricultural purposes. In-depth analysis clearly demonstrates that the proposed ENHS not only offers electricity and cooking gas to the community with the lowest costs, but also reduces the energy crisis and GHG emissions and can play an active role in developing socio-economic infrastructure of rural communities in Bangladesh in many ways

Investigations on the redox behaviour of manganese in manganese(II)–saccharin and manganese(II)–saccharin–1,10-phenanthroline complexes

AbstractThe redox behaviour of manganese system in Mn–Sac and Mn–Sac–Phen complexes were studied using cyclic voltammetry technique at glassy carbon electrode (GCE) in 0.1M KCl electrolyte. The CV of Mn–Sac solution is more or less similar to that of uncoordinated Mn (in MnCl2) accept slight difference in peak position and peak current. The presence of secondary ligand phenanthroline (in Mn–Sac–Phen complex) changes the CV of Mn system largely compared to those of uncoordinated Mn and Mn–Sac. The redox system is irreversible in Mn–Sac and quasi-reversible in Mn–Sac–Phen complex. The effect of concentration and pH on the redox behaviour of Mn system have been studied for both the complexes

Predicting the environmental suitability for onchocerciasis in Africa as an aid to elimination planning

Recent evidence suggests that, in some foci, elimination of onchocerciasis from Africa may be feasible with mass drug administration (MDA) of ivermectin. To achieve continental elimination of transmission, mapping surveys will need to be conducted across all implementation units (IUs) for which endemicity status is currently unknown. Using boosted regression tree models with optimised hyperparameter selection, we estimated environmental suitability for onchocerciasis at the 5 × 5-km resolution across Africa. In order to classify IUs that include locations that are environmentally suitable, we used receiver operating characteristic (ROC) analysis to identify an optimal threshold for suitability concordant with locations where onchocerciasis has been previously detected. This threshold value was then used to classify IUs (more suitable or less suitable) based on the location within the IU with the largest mean prediction. Mean estimates of environmental suitability suggest large areas across West and Central Africa, as well as focal areas of East Africa, are suitable for onchocerciasis transmission, consistent with the presence of current control and elimination of transmission efforts. The ROC analysis identified a mean environmental suitability index of 071 as a threshold to classify based on the location with the largest mean prediction within the IU. Of the IUs considered for mapping surveys, 502% exceed this threshold for suitability in at least one 5 × 5-km location. The formidable scale of data collection required to map onchocerciasis endemicity across the African continent presents an opportunity to use spatial data to identify areas likely to be suitable for onchocerciasis transmission. National onchocerciasis elimination programmes may wish to consider prioritising these IUs for mapping surveys as human resources, laboratory capacity, and programmatic schedules may constrain survey implementation, and possibly delaying MDA initiation in areas that would ultimately qualify.SUPPORTING INFORMATION : FIGURE S1. Data coverage by year. Here we visualise the volume of data used in the analysis by country and year. Larger circles indicate more data inputs. ‘NA’ indicates records for which no year was reported (eg, ‘pre-2000’). https://doi.org/10.1371/journal.pntd.0008824.s001FIGURE S2. Illustration of covariate values for year 2000. Maps were produced using ArcGIS Desktop 10.6. https://doi.org/10.1371/journal.pntd.0008824.s002FIGURE S3. Environmental suitability of onchocerciasis including locations that have received MDA for which no pre-intervention data are available. This plot shows suitability predictions from green (low = 0%) to pink (high = 100%), representing those areas where environmental conditions are most similar to prior pathogen detections. Countries in grey with hatch marks were excluded from the analysis based on a review of national endemicity status. Areas in grey only represent locations masked due to sparse population. Maps were produced using ArcGIS Desktop 10.6 and shapefiles to visualize administrative units are available at https://espen.afro.who.int/tools-resources/cartography-database. https://doi.org/10.1371/journal.pntd.0008824.s003FIGURE S4. Environmental suitability prediction uncertainty including locations that have received MDA for which no pre-intervention data are available. This plot shows uncertainty associated with environmental suitability predictions colored from blue to red (least to most uncertain). Countries in grey with hatch marks were excluded from the analysis based on a review of national endemicity status. Areas in grey only represent locations masked due to sparse population. Maps were produced using ArcGIS Desktop 10.6 and shapefiles to visualize administrative units are available at https://espen.afro.who.int/tools-resources/cartography-database. https://doi.org/10.1371/journal.pntd.0008824.s004FIGURE S5. Environmental suitability of onchocerciasis excluding morbidity data. This plot shows suitability predictions from green (low = 0%) to pink (high = 100%), representing those areas where environmental conditions are most similar to prior pathogen detections. Countries in grey with hatch marks were excluded from the analysis based on a review of national endemicity status. Areas in grey only represent locations masked due to sparse population. Maps were produced using ArcGIS Desktop 10.6 and shapefiles to visualize administrative units are available at https://espen.afro.who.int/tools-resources/cartography-database. https://doi.org/10.1371/journal.pntd.0008824.s005FIGURE S6. Environmental suitability prediction uncertainty excluding morbidity data. This plot shows uncertainty associated with environmental suitability predictions colored from blue to red (least to most uncertain). Countries in grey with hatch marks were excluded from the analysis based on a review of national endemicity status. Areas in grey only represent locations masked due to sparse population. https://doi.org/10.1371/journal.pntd.0008824.s006FIGURE S7. Covariate Effect Curves for all onchocerciasis occurrences (measures of infection prevalence and disability). On the right set of axes we show the frequency density of the occurrences taking covariate values over 20 bins of the horizontal axis. The left set of axes shows the effect of each on the model, where the mean effect is plotted on the black line and its uncertainty is represented by the upper and lower confidence interval bounds plotted in dark grey. The figures show the fit per covariate relative to the data that correspond to specific values of the covariate. https://doi.org/10.1371/journal.pntd.0008824.s007FIGURE S8. Covariate Effect Curves for all onchocerciasis occurrences (measures of infection prevalence and disability). On the right set of axes we show the frequency density of the occurrences taking covariate values over 20 bins of the horizontal axis. The left set of axes shows the effect of each on the model, where the mean effect is plotted on the black line and its uncertainty is represented by the upper and lower confidence interval bounds plotted in dark grey. https://doi.org/10.1371/journal.pntd.0008824.s008FIGURE S9. ROC analysis for threshold. Results of the area under the receiver operating characteristic (ROC) curve analysis are presented below, with false positive rate (FPR) on the x-axis and true positive rate (TPR) on the y-axis. The red dot on the curve represents the location on the curve that corresponds to a threshold that most closely agreed with the input data. For each of the 100 BRT models, we estimated the optimal threshold that maximised agreement between occurrence inputs (considered true positives) and the mean model predictions as 0·71. https://doi.org/10.1371/journal.pntd.0008824.s009TABLE S1. Guidelines for Accurate and Transparent Health Estimates Reporting (GATHER) checklist. https://doi.org/10.1371/journal.pntd.0008824.s010TABLE S2. Total number of occurrence data classified as point and polygon inputs by diagnostic. We present the total number of occurrence points extracted from the input data sources by diagnostic type. ‘Other diagnostics’ include: DEC Patch test; Knott’s Method (Mazotti Test); 2 types of LAMP; blood smears; and urine tests. https://doi.org/10.1371/journal.pntd.0008824.s011TABLE S3. Total number of occurrence data classified as point and polygon inputs by location. https://doi.org/10.1371/journal.pntd.0008824.s012TABLE S4. Covariate information. https://doi.org/10.1371/journal.pntd.0008824.s013TEXT S1. Details outlining construction of occurrence dataset. https://doi.org/10.1371/journal.pntd.0008824.s014TEXT S2. Covariate rationale. https://doi.org/10.1371/journal.pntd.0008824.s015TEXT S3. Boosted regression tree methodology additional details. https://doi.org/10.1371/journal.pntd.0008824.s016APPENDIX S1. Country-level maps and data results. Maps were produced using ArcGIS Desktop 10.6 and shapefiles to visualize administrative units are available at https://espen.afro.who.int/tools-resources/cartography-database. https://doi.org/10.1371/journal.pntd.0008824.s017This work was primarily supported by a grant from the Bill & Melinda Gates Foundation OPP1132415 (SIH). Financial support from the Neglected Tropical Disease Modelling Consortium (https://www.ntdmodelling.org/), which is funded by the Bill & Melinda Gates Foundation (grants No. OPP1184344 and OPP1186851), and joint centre funding (grant No. MR/R015600/1) by the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement which is also part of the EDCTP2 programme supported by the European Union (MGB).The Neglected Tropical Disease Modelling Consortium which is funded by the Bill & Melinda Gates Foundation, the UK Medical Research Council (MRC) and the UK Department for International Development (DFID) under the MRC/DFID Concordat agreement which is also part of the EDCTP2 programme supported by the European Union (MGB).http://www.plosNTDS.orgam2022Medical Microbiolog

Publisher's Note: “A practical biogas based energy neutral home system for rural communities of Bangladesh” [J. Renewable Sustainable Energy 8, 023101 (2016)]

This article was originally published online on 2 March 2016 with an error in the first initials of author GM Shafiullah: “G.M.” has been corrected to “GM” and appears accurately above. In addition, there was an error in Table IX: The value “35 000” under the column labeled “BDT/year” was incorrectly set on the line corresponding to “Variable operational cost (VOC)”; 35 000 should have been set on the line corresponding to “Overheads.” AIP Publishing apologizes for these errors. All online versions of the article were corrected on 15 March 2016

Satellite radar altimetry waveform retracking over the Caspian Sea

Post-processing of complex altimetry-derived echo shapes is necessary over the Caspian Sea, in which the altimetry-inferred level fluctuations, derived from on-board ‘retrackers’, represent errors within a wide boundary close to the coastlines, i.e. up to ~10–30 km. Four different techniques were implemented to retrack 10 Hz radar waveforms of the TOPEX/Poseidon (T/P) mission and 20 Hz waveforms of its follow-on mission Jason-1. These include three previously introduced algorithms of the Off Center of Gravity, the standard NASA β-5, and Threshold Retracking, after some improvements. We also introduced a new method called ‘Extrema Retracking (ExtR)’, which works based on edge detection and extracting extremum points of the returned waveforms. Before implementing each technique, a two-step preprocessing was applied to exclude unwanted waveforms. Then, an unsupervised classification approach was applied to classify the remaining waveforms into multiple groups, according to their shape and geometrical properties. Finally, the waveforms of each group were post-processed using an appropriate retracking algorithm, and subsequently, the derived corrected ranges were converted to sea surface height (SSH) values. Our post-processed results were evaluated (1) by comparing the time series of SSHs with in situ tide gauge measurements as well as (2) by comparing the along-track retracked SSHs to their corresponding geoid profiles, computed from the EGM2008 model. For each evaluation, in situ measurements or geoid profiles were subtracted from the retracked SSH values to compute residuals. Thereafter, the mean and root mean squares of the residuals were calculated and interpreted, respectively, as a measure of bias and noise level of the processed SSHs. Our results indicated a reduction in noise and bias after the application of retrackers. Specifically, the bias and noise of the ExtR-derived SSH time series were decreased at locations close to the Anzali, Noshahr and Neka tide-gauge stations (along the southern coast). For example, the correlation between altimetry observations and tide gauge measurements close to the Anzali Port over the T/P era was increased from 0.31 (using original altimetry data) to 0.83 (using ExtR), which is equivalent to a noise reduction of 0.58 to 0.39 m. Comparisons of the along-track SSHs with geoid profiles indicated a significant mitigation of land contamination over the coastal areas

Aerosol assisted chemical vapor deposition of magnesium orthotitanate (Mg 2 TiO 4 ) films from a trinuclear molecular precursor

Present work demonstrates the synthesis of a novel heterobimetallic complex [Mg2TiO(TFA)6(THF)2(H2O)] (1) (where TFA = trifluoroacetato and THF = tetrahydrofuran), formed from the chemical interaction of magnesium (II) acetate tetrahydrate with titanium (IV) isopropoxide and trifluoroacetic acid in THF solution. Complex (1) adequately characterized through attenuated total reflection infrared spectroscopy, single-crystal X-ray diffraction and thermogravimetric analysis was implemented as single source molecular precursor in the aerosol assisted chemical vapor deposition. The deposition of magnesium orthotitanate (Mg2TiO4) ceramic films on fluorine doped tin oxide coated conducting glass substrate was observed at various temperatures of 500, 550 and 600 °C. Film characterization techniques including; X-ray powder diffraction, scanning electron microscopy, energy dispersive X-ray and X-ray photoelectron spectroscopy divulge the fabrication of phase pure spherical shaped Mg2TiO4 architectures with precise stoichiometry and high purity

Investigation of the structural and mechanical properties of micro-/nano-sized Al2O3 and cBN composites prepared by spark plasma sintering

YesAlumina-cubic boron nitride (cBN) composites were prepared using the spark plasma sintering (SPS) technique. Alpha-alumina powders with particle sizes of ∼15 µm and ∼150 nm were used as the matrix while cBN particles with and without nickel coating were used as reinforcement agents. The amount of both coated and uncoated cBN reinforcements for each type of matrix was varied between 10 to 30 wt%. The powder materials were sintered at a temperature of 1400 °C under a constant uniaxial pressure of 50 MPa. We studied the effect of the size of the starting alumina powder particles, as well as the effect of the nickel coating, on the phase transformation from cBN to hBN (hexagonal boron nitride) and on the thermo-mechanical properties of the composites. In contrast to micro-sized alumina, utilization of nano-sized alumina as the starting powder was observed to have played a pivotal role in preventing the cBN-to-hBN transformation. The composites prepared using nano-sized alumina reinforced with nickel-coated 30 wt% cBN showed the highest relative density of 99% along with the highest Vickers hardness (Hv2) value of 29 GPa. Because the compositions made with micro-sized alumina underwent the phase transformation from cBN to hBN, their relative densification as well as hardness values were relatively low (20.9–22.8 GPa). However, the nickel coating on the cBN reinforcement particles hindered the cBN-to-hBN transformation in the micro-sized alumina matrix, resulting in improved hardness values of up to 24.64 GPa

Effect of AACVD processing parameters on the growth of Greenockite (CdS) thin films using a single-source cadmium Precursor

Greenockite (CdS) nanostructured thin films are deposited on soda and FTO conducting glass substrates by aerosol-assisted (AA)CVD using a single-source precursor bis-(N,N-dicylcohexyldithiocarbamato)(pyridine)cadmium(II), CdS 2CNCy 2 2.py (1), in pyridine, toluene, and THF solutions in the temperature range 350-450 °C. The precursor 1, characterized by physicochemical methods, undergoes facile thermal decomposition at 350 °C to give a stable residual mass of CdS. The thin films deposited from pyridine solution, and characterized by X-ray diffraction (XRD), UV-vis spectroscopy, field-emission scanning electron microscopy (FESEM), and energy dispersive X-ray (EDX) techniques, exhibit a band gap of 2.4 eV and a photocurrent density of 1.3 mA cm -2 at 0.4 V versus Ag/AgCl/3M KCl, suggesting their suitability for application in photoelectrochemical (PEC) cells