Domestic Water and Sanitation in Cyclones and Floods in Bangladesh and a Proposed Research Agenda

ABSTRACT

Water is one of the top priority item s i relief activities but the appropriateness and effectiveness of this activity may be questioned. Water and sanitation (WS) are inseparable and together they play major roles in the transmission of the pathogen of diarrhoeal disease. Thousands of people die or suffer from WS-related diseases during postdisaster periods. Here we present WS-related experiences gained after Bangladesh's 1991 cyclone and the views of participants in a regional and a national (local) workshop on this matter held in Bangladesh. About 63 per cent of the water purifying tablets (WPTs) distributed after the 1991 cyclone were found to have lost potency Relief personnel lack basic knowledge about WS practices and the management of WS provision. Participants in the two workshops documented serious problems i this field at both regional and national levels. Major issues for research may include: an appropriate environmental preparedness plan; appropriate waste disposal technologies; appropriate water treatment methods; self- help activities during vulnerable periods; and health education related to WS in disaster situations.     

Feasibility of generating biometric encryption keys

A scheme to generate encryption keys from biometric samples is introduced. The idea is based on partitioning feature space into subspaces and partitioning these into cells. Each cell subspace contributes to the overall key generated. Experimental analysis shows encouraging prospects.     

Waveguide slot element

A waveguide slot element, excited by a thin strip, printed and kept behind the slot is presented. The slot is vertical and non-wrap around, whereas the strip is inclined with respect to the slot or takes an L-shape. The strip and the slot are printed simultaneously on a dielectric substrate and replaces the narrow wall of the guide. The use of printed circuit technique leads to good accuracy and square ended slots. A wide range of admittance can be realised by choosing the strip parameters     

Dielectric Relaxation and Conductivity of Ba(Mg1/3Ta2/3)O3and Ba(Zn1/3Ta2/3)O3

The frequency dependent dielectric properties of barium magnesium tantalate(BMT),Ba(Mg_(1/3)Ta(2/3))O_3 and barium zinc tantalate(BZT),Ba(Zn_(1/3)Ta_(2/3))O_3 synthesized by solid state reaction technique have been investigated at various temperatures by impedance spectroscopy.BMT and BZT possess cubic structure with lattice parameter a = 0.708 and 0.451 nm,respectively.The resonance peaks due to dielectric relaxation processes are observed in the loss tangent of these oxides.The relaxation in the samples is polydispersive in nature.The temperature dependence of dc conductivity,the most probable relaxation frequency(ω_m) obtained from tanδ vs logw plots and ω_m obtained from imaginary parts of the complex electrical modulus vs logw plots follow the Arrhenius behavior.According to these Arrhenius plots the activation energies of BMT and BZT are about 0.54 and 0.40 eV,respectively.Thus the results indicate that samples are semiconducting in nature.The frequency-dependent electrical data are analyzed in the framework of conductivity and electric modulus formalisms.Both these formalisms show qualitative similarities in relaxation time.Our study points that for complex perovskite oxides with general formula A(B'B")O_3,the dielectric properties significantly depend on the atomic radii of both A and B type cations.BMT and BZT exhibit enhancement in dielectric property compared to their niobate counterparts.They may find several technological applications such as in capacitors,resonators and filters owing to their high dielectric constant and low loss tangent.     

Development and Simulation of Sulfur‐doped Graphene Supported Platinum with Exemplary Stability and Activity Towards Oxygen Reduction

Sulfur‐doped graphene (SG) is prepared by a thermal shock/quench anneal process and investigated as a unique Pt nanoparticle support (Pt/SG) for the oxygen reduction reaction (ORR). Particularly, SG is found to induce highly favorable catalyst‐support interactions, resulting in excellent half‐cell based ORR activity of 139 mA mg_Pt ^?1 at 0.9 V vs RHE, significant improvements over commercial Pt/C (121 mA mg_Pt ^?1) and Pt‐graphene (Pt/G, 101 mA mg_Pt ^?1). Pt/SG also demonstrates unprecedented stability, maintaining 87% of its electrochemically active surface area following accelerated degradation testing. Furthermore, a majority of ORR activity is maintained, providing 108 mA mg_Pt ^?1, a remarkable 171% improvement over Pt/C (39.8 mA mg_Pt ^?1) and an 89% improvement over Pt/G (57.0 mA mg_Pt ^?1). Computational simulations highlight that the interactions between Pt and graphene are enhanced significantly by sulfur doping, leading to a tethering effect that can explain the outstanding electrochemical stability. Furthermore, sulfur dopants result in a downshift of the platinum d‐band center, explaining the excellent ORR activity and rendering SG as a new and highly promising class of catalyst supports for electrochemical energy technologies such as fuel cells.     

Socioeconomic development, status of women, family planning, and fertility in Bangladesh: a district level analysis

In this paper we examine the effects of socioeconomic development, the status of women, and family planning on fertility and the extent to which these effects vary among the nineteen districts of Bangladesh. The 1983 and 1991 Bangladesh Contraceptive Prevalence Survey data are used to examine the effects of these factors on differences in contraceptive use among currently married women aged 15-49. The proportion of currently married women aged 15-49 using contraception was 46.3 per cent in 1991, a considerable increase from 26.5 per cent in 1983. Contraceptive use rates for all the districts increased substantially over the period between 1983 and 1991 and the gap between Dhaka's rate and those of other districts was narrower in 1991 than in 1983. An analytical model composed of socioeconomic development, status of women, and family planning variables is tested using logistic regression. The logit model is used to evaluate the effects of a selected group of variables on the probability of using contraceptive methods. The analysis demonstrates clearly that socioeconomic development and women's status significantly impact the use of contraceptive methods in Bangladesh. The results also suggest that better-educated, employed women are more likely to use contraception than those who have little or no formal education and who are not employed. In 1983, rural-urban differences in contraceptive use were significant, but in 1991 area of residence was not significant, which suggests that family planning programs may have played an important role in providing contraceptive information and technology to rural areas. Our analysis also suggests that family planning programs operated more efficiently in some districts than in others, and regional differences remained important in 1991 as they were in 1983. Decomposition analysis suggests that shifts in population structure favored increased contraceptive use in Bangladesh. This analysis also indicates that change in rate is also important, contributing about 21 per cent of the overall increase in contraceptive use.     

Increased matrix metalloproteinase-2 activity induced by TGF-beta 1 in duct cells of human salivary gland is associated with the development of cyst formation in vivo

Proteolytic enzyme activity has been shown to be important for cyst formation. In this study, we constructed a cyst-like structure in vivo and analyzed molecular mechanisms involved in the development of the lesion. When SV40-immortalized duct cells of normal human salivary gland (NS-SV-DC) were treated with TGF-beta 1 at a concentration of 1 ng/ml or 5 ng/ml followed by co-inoculation with Matrigel into the backs of nude mice, they formed large cysts containing fluid when 5 ng/ml of TGF-beta 1 was used. Analysis of the fluid demonstrated high MMP activity. Immunohistochemical staining exhibited strong reactivity with anti-MMP-2 antibody in TGF-beta 1 (5 ng/ml)-treated NS-SV-DC. Northern blot analysis indicated that the expression of TGF-beta 1 and MMP-2 mRNAs in cells was greatly enhanced by treatment with 5 ng/ml TGF-beta 1. These findings suggest that the in vivo cyst formation by TGF-beta 1-treated cells is associated with continuous induction of MMP-2 activity.     

Predicting Drying Performance of Osmotically Treated Heat Sensitive Products Using Artificial Intelligence

The main goal of this research is to develop and apply a robust Artificial Neural Networks (ANNs) model for predicting the characteristics of the osmotically drying treated potato and apple samples as a model heat-sensitive product in vacuum contact dryer. Concentrated salt and sugar solutions were used as the osmotic solutions at 27C. Series of experiments were performed at various temperatures of 35C, 40C, and 55C for conduction heat input under vacuum ( −760 mm Hg) condition. Some experiments were also performed in a pure vacuum without heat addition. Dimensionless moisture content (DMC), effective moisture diffusivity, and mass flux were considered as the performance parameters in this study. Results revealed that the osmotic dehydration using a concentrated sugar solution shows a higher reduction in the initial moisture loss of 19.87% compared to 5.3% in the salt solution. Furthermore, a significant enhancement of drying performance of about 27% in DMC was observed for both samples at vacuum and 40C compared to pure vacuum drying conditions. Using the experimental data, a robust artificial neural network (ANN) was proposed to describe the osmotic dehydration’s behavior on the drying process. The ANN model outputs are the dimensionless moisture contents (DMC), the diffusivity, and the mass flux. Whereas the ANN inputs were the drying time, the percent of sugar solution, and the percent of salt solution. For the ANN apple’s model, the minimum root mean square error (RMSE) values were 0.0261, 0.0349 and 0.0406, for DMC, diffusivity, and mass flux, respectively. Whereas the best correlation coefficients of the above three parameters’ determination values were 0.9909, 0.9867 and 0.9744, respectively. For the ANN potato’s model, the minimum RMSE values were 0.0124, 0.0140 and 0.0333, for DMC, diffusivity, and mass flux, respectively. And the best correlation coefficients of the parameters’ values were found 0.9969, 0.9968 and 0.9736, respectively. Accordingly, the ANN model’s prediction has a perfect agreement with the experimental dataset, which confirmed the ANN model’s accuracy.