Hybrid power supply solutions for off-grid green wireless networks

Increasing deployment of cellular networks across the globe is pushing the energy consumption in cellular networks at an exceptional rate. The integration of renewable energy (RE) harvesting technology into future mobile networks has the potential to positively cope with environmental contamination and ensure self-energy sustainability as a means to decrease fossil fuel consumption. Diesel generator (DG) in conjunction with on-site RE harvester has emerged as an economic and extent efficient option where commercial grid supply is not viable. This paper is focused on the cost aware energy management framework addressing to least net present cost (NPC) for the envisioned hybrid powered green cellular base stations (BSs) considering tempo-spatial traffic dynamics. In such wireless networks, solar photovoltaic modules are considered as a primary energy source, while the DG and energy storage device are kept as the standby supply in case of inadequate solar energy to ensure zero outage. A comprehensive simulation-based investigation is carried out in the context of downlink Long-Term Evolution (LTE) cellular networks for evaluating cost-efficiency and reliability performance under a wide range of network settings. Particularly, this paper examines the energy yield, greenhouse gas emissions, and cost analysis based on the optimal architecture of Remote Radio Head-enabled LTE BS. Moreover, wireless network performance in terms of throughput, energy efficiency gain, and radio efficiency is thoroughly investigated using Monte Carlo simulations. Numerical results demonstrate a substantial reduction of carbon footprints with minimum NPC while satisfying the quality of service requirements.     

In situ hybridization studies for the detection of common aneuploidies in CVS

We have attempted to evaluate the efficiency of interphase cytogenetics in the detection of specific aneuploidies in chorionic villus samples. For this purpose, we used alphoid repetitive sequences specific for the chromosomes involved in the common aneuploidies, namely probes for chromosomes 13, 18, 21, X, and Y. These probes were applied to normal and abnormal CVS cases, as well as to a few mosaic cases. Results from these preliminary studies indicate that the technique can be very efficient for the detection of specific aneuploidies and can be particularly useful in the analysis of mosaic cases, which usually requires the screening of high number of metaphases.     

Methane emissions and related physicochemical soil and water parameters in rice–fish systems in Bangladesh

Lowland rice fields constitute a semi aquatic environment, which is potentially suitable for fish production. Little is known about the effect of fish on greenhouse gas emissions from integrated rice–fish systems. An experiment was carried out at the Bangladesh Agricultural University to assess the effect of the stocking of fish on methane emissions from rice fields. Common carp, Cyprinus carpio L., and Nile Tilapia, Oreochromis niloticus (L.) were stocked in a mixed culture and subjected to three different input regimes: (1) urea fertilization according to the recommendation of the Bangladesh Rice Research Institute (BRRI), (2) supplementary feeding at 2 × maintenance level and (3) an elevated feeding schedule where 4 × maintenance level was fed initially and 2 × maintenance level towards the end of the growth period. Rice only with urea fertilization according to BRRI-recommendation was included as the control. The presence of fish increased methane emissions in all three rice–fish treatments. Average emission over the cropping season was 34, 37, and 32 mg m⁻² h⁻¹ in the rice–fish treatments, respectively, and 20 mg m⁻² h⁻¹ in rice only. Apart from an increase in methane emission, a significant drop (p < 0.05) in floodwater pH and dissolved oxygen concentration was observed in the rice–fish plots. Both parameters were the lowest in the treatment where a higher feeding rate was provided. Due to the fish activity, floodwater in the rice–fish treatments was more turbid, as reflected in higher particulate inorganic matter (PIOM). An elevated level of dissolved methane was observed in the floodwater of the feed supplemented rice–fish plots. Methane emissions showed negative correlation with morning and afternoon pH of the floodwater (r = −0.46; r = −0.56, p < 0.001) and morning and afternoon dissolved oxygen level (r = −0.53; r = −0.46, p < 0.001). Positive correlations were recorded between morning and afternoon floodwater temperature (r = 0.49; r = 0.44, p < 0.001) and with air temperature (r = 0.54, p < 0.001). The results suggest that the stocking of fish has an increasing effect on methane emissions from rice fields.     

Chromosome banding in direct preparations of chorionic villi

Chorionic villus sampling (CVS) is now currently offered for first trimester prenatal diagnosis of genetic disorders. Chromosome analysis of CVS in direct and culture preparations is possible using modifications of standard banding techniques. We summarize our experience in applying QFQ, GTG, RBG, CBG, DA/DAPI, NOR, and SC differentiation protocols to direct preparations. Characteristic chromosome regions are properly labelled by these techniques, and analysis of 300 band stage karyotypes is consistently achievable on GTG banded direct preparations. However, banding of CVS direct chromosomes has proved to be difficult, and the analysis needs to be backed up by culture preparations.     

Clinical solid waste management practices and its impact on human health and environment--A review

The management of clinical solid waste (CSW) continues to be a major challenge, particularly, in most healthcare facilities of the developing world. Poor conduct and inappropriate disposal methods exercised during handling and disposal of CSW is increasing significant health hazards and environmental pollution due to the infectious nature of the waste. This article summarises a literature review into existing CSW management practices in the healthcare centers. The information gathered in this paper has been derived from the desk study of open literature survey. Numerous researches have been conducted on the management of CSW. Although, significant steps have been taken on matters related to safe handling and disposal of the clinical waste, but improper management practice is evident from the point of initial collection to the final disposal. In most cases, the main reasons of the mismanagement of CSW are the lack of appropriate legislation, lack of specialized clinical staffs, lack of awareness and effective control. Furthermore, most of the healthcare centers of the developing world have faced financial difficulties and therefore looking for cost effective disposal methods of clinical waste. This paper emphasizes to continue the recycle-reuse program of CSW materials after sterilization by using supercritical fluid carbon dioxide (SF-CO2) sterilization technology at the point of initial collection. Emphasis is on the priority to inactivate the infectious micro-organisms in CSW. In that case, waste would not pose any threat to healthcare workers. The recycling-reuse program would be carried out successfully with the non-specialized clinical staffs. Therefore, the adoption of SF-CO2 sterilization technology in management of clinical solid waste can reduce exposure to infectious waste, decrease labor, lower costs, and yield better compliance with regulatory. Thus healthcare facilities can both save money and provide a safe environment for patients, healthcare staffs and clinical staffs.     

Additional danger of arsenic exposure through inhalation from burning of cow dung cakes laced with arsenic as a fuel in arsenic affected villages in Ganga-Meghna-Brahmaputra plain

In arsenic contaminated areas of the Ganga-Meghna-Brahmaputra (GMB) plain (area 569,749 sq. km; population over 500 million) where traditionally cow dung cake is used as a fuel in unventilated ovens for cooking purposes, people are simply exposed to 1859.2 ng arsenic per day through direct inhalation, of which 464.8 ng could be absorbed in respiratory tract.     

Influence of multi-industrial activities on trace metal contamination: an approach towards surface water body in the vicinity of Dhaka Export Processing Zone (DEPZ)

Industrial wastewater discharged into aquatic ecosystems either directly or because of inadequate treatment of process water can increase the concentrations of pollutants such as toxic metals and others, and subsequently deteriorate water quality, environmental ecology and human health in the Dhaka Export Processing Zone (DEPZ), the largest industrial belt of 6-EPZ in Bangladesh. Therefore, in order to monitor the contamination levels, this study collected water samples from composite effluent points inside DEPZ and the surrounding surface water body connected to effluent disposal sites and determined the environmental hazards by chemical analysis and statistical approach. The water samples were analysed by inductively coupled plasma mass spectrometry to determine 12 trace metals such as As, Ag, Cr, Co, Cu, Li, Ni, Pb, Se, Sr, V and Zn in order to assess the influence of multi-industrial activities on metal concentrations. The composite effluents and surface waters from lagoons were characterized by a strong colour and high concentrations of biochemical oxygen demand, chemical oxygen demand, electrical conductivity, pH, total alkalinity, total hardness, total organic carbon, Turb., Cl(-), total suspended solids and total dissolved solids, which were above the limit of Bangladesh industrial effluent standards, but dissolved oxygen concentration was lower than the standard value. The measurement of skewness and kurtosis values showed asymmetric and abnormal distribution of the elements in the respective phases. The mean trend of variation was found in a decreasing order: Zn > Cu > Sr > Pb > Ni > Cr > Li > Co > V > Se > As > Ag in composite industrial effluents and Zn > Cu > Sr > Pb > Ni > Cr > Li > V > As > Ag > Co > Se in surface waters near the DEPZ. The strong correlations between effluent and surface water metal contents indicate that industrial wastewaters discharged from DEPZ have a strong influence on the contamination of the surrounding water bodies by toxic metals. The average contamination factors were reported to be 0.70-96.57 and 2.85-1,462 for industrial effluents and surface waters, respectively. The results reveal that the surface water in the area is highly contaminated with very high concentrations of some heavy/toxic metals like Zn, Pb, Cu, Ni and Cr; their average contamination factors are 1,460, 860, 136, 74.71 and 4.9, respectively. The concentrations of the metals in effluent and surface water were much higher than the permissible limits for drinking water and the world average concentrations in surface water. Therefore, the discharged effluent and surface water may create health hazards especially for people working and living inside and in the surrounding area of DEPZ.     

Soil salinity,household wealth and food insecurity in tropical deltas: evidence from south-west coast of Bangladesh

As a creeping process, salinisation represents a significant long-term environmental risk in coastal and deltaic environments. Excess soil salinity may exacerbate existing risks of food insecurity in densely populated tropical deltas, which is likely to have a negative effect on human and ecological sustainability of these regions and beyond. This study focuses on the coastal regions of the Ganges–Brahmaputra delta in Bangladesh, and uses data from the 2010 Household Income and Expenditure Survey and the Soil Resource Development Institute to investigate the effect of soil salinity and wealth on household food security. The outcome variables are two widely used measures of food security: calorie availability and household expenditure on food items. The main explanatory variables tested include indicators of soil salinity and household-level socio-economic characteristics. The results of logistic regression show that in unadjusted models, soil salinisation has a significant negative effect on household food security. However, this impact becomes statistically insignificant when households’ wealth is taken into account. The results further suggest that education and remittance flows, but not gender or working status of the household head, are significant predictors of food insecurity in the study area. The findings indicate the need to focus scholarly and policy attention on reducing wealth inequalities in tropical deltas in the context of the global sustainable deltas initiative and the proposed Sustainable Development Goals.     

Vertical distribution and contamination assessment of heavy metals in sediment cores of ship breaking area of Bangladesh

Environmental Geochemistry and Health - Vertical heavy metal profiling reflects the history of the deposition of metals and helps to understand the characteristics of accumulation in various layers...     

Space-time Bayesian small area disease risk models: development and evaluation with a focus on cluster detection

This paper extends the spatial local-likelihood model and the spatial mixture model to the space-time (ST) domain. For comparison, a standard random effect space-time (SREST) model is examined to allow evaluation of each model’s ability in relation to cluster detection. To pursue this evaluation, we use the ST counterparts of spatial cluster detection diagnostics. The proposed criteria are based on posterior estimates (e.g., misclassification rate) and some are based on post-hoc analysis of posterior samples (e.g., exceedance probability). In addition, we examine more conventional model fit criteria including mean square error (MSE). We illustrate the methodology with a real ST dataset, Georgia throat cancer mortality data for the years 1994–2005, and a simulated dataset where different levels and shapes of clusters are embedded. Overall, it is found that conventional SREST models fair well in ST cluster detection and in goodness-of-fit, while for extreme risk detection the local likelihood ST model does best.