Archives-December 

Analysis of earth dams Stability, and their arching phenomenon, is one of the most important issues in geotechnical engineering. Arching dam, you can use one or more methods are analyzed. The main factor of instability dams, gravity effect, but other factors can, intensify or provoke them to be effective. To understand the factors intensifying landslide, could contribute significantly to the experts, and the stability of the dam dirt, and prevent the arching. The purpose of this paper is to examine the phenomenon of arching in the bathroom tight barrier with finite element method, and compared with studies of dam instrumentation, numerical analysis by finite element software PLAXIS, has been made. Analysis, using behavioral models Mohr-Coulomb, is done. On the other hand, we can say that, numerical methods in the analytical methods is very rapid, reliable and accurate, and therefore these methods, able to perform parametric studies, the boundary conditions are complex. So in this study, AH stresses dam Tang-e Hamam, has been studied, and then perform parametric studies, it was concluded that increasing the angle of internal friction shell dam, the dam will lead to increased confidence. However, by changing the geometry of the dam core, core thickness miles to miles and increase confidence rises Dam. Also, the arching, the barrier height is variable, and strongly arching and the maximum arching, core thickness depends on the height of the dam.

This study is a first neuropsychological evaluation of cognitive Impairment generated by the job strain to the teleoperators in call centers in sub-Saharan Africa; Particularly in the Democratic Republic of Congo, city of kinshasa. This study established a statistically significant relationship between Exposure to psychosocial factors (high psychological demand and low decision latitude) and the appearance of job strain in teleoperators. It also showed a statistically significant relationship between job strain and the appearance of cognitive disorders in teleoperators. Lastly, the exposure duration at the call center of six months or more, was retained as necessary time to see the psychosocial factors negatively impacting the mental health of the call center teleoperators.

This paper takes a look at Campus Radio Presentation World from analytical secondary data and observers discovery over a span of many years of professional radio broadcasting practice and offered different perspectives with recommendations for excellent presentations on Campus Radio.

In this paper, a helical coil tube in tube heat exchanger was designed and used in carbon dioxide solar assisted heat pump system (SAHP) to provide hot water for domestic applications and to operate an air gap membrane desalination (AGMD) unit. Both theoretical and experimental studies to investigate the performance of the gas cooler with Glycol Ethylene 50% and water as coolants were performed. The experimental part to study the behavior of the carbon dioxide in the supercritical region was conducted on the R744 heat pump test rig located at Department of Energy and Process Engineering – NTNU. On the other hand, FEA using ANSYS Fluent 18.1 was used to conduct the theoretical analysis. The study includes effect of inlet temperature of both coolants, effect of discharge pressure, effect of mass flow rate of water, and logarithmic mean temperature difference (LMTD). Good agreements between Experimental and simulation results were achieved. Results showed that the outlet temperature of the refrigerant from the gas cooler decreased from 81 oC to 40 oC, with 0.085 bar average pressure drop due to the heat rejection process. The outlet temperature of the refrigerant from the gas cooler in case of water is 8 oC lower than with ethylene glycol 50%. The outlet temperature of water reached 57 oC which is enough for domestic applications and to operate the AGMD unit to produce fresh water. It is observed that the pressure drop in the refrigerant by using water as coolant is higher by 0.2 bar than when ethylene glycol 50% used. Results also revealed that the value of LMTD of the gas cooler using ethylene glycol 50% is 24.3 % higher than the LMTD value when using water.

A tree T is called starlike [2], if it contains a vertex v for which deg (v) ? 3 and all other vertices of T have degree 1 or 2. If deg (v) = k, the starlike tree T is k – branched and T – v has k components, each of which are trees. In this paper, we characterize the 3 – branched starlike spanning trees of a given two dimensional mesh M(m, n) m, n ? 3 and then find its number with junction vertex [2] of degree 3.

100 g of dried leaves of Mentha spicata produced 1.1% of volatile oil by hydro distillation method. GC-MS, method used to identified the chemical compound of the volatile oil, it contained eighteen compounds, ten of them constituted as the major compounds, carvone (58.3%), cis-carveol 14.99%), limonene (8.5%), carvyl acetate (3.10%), ?-pinene (1.22%), ß –Pinene (2.11%), Menthone (1.08%), Menthol (1.01%), ß- bourbonene (1.98) and trans-Caryophyllene (1.75). The spearmint volatile oil more actively against gram positive bacteria (Staphylococcus aurous and Bacillus cereus) than gram negative bacteria,( Escherichia coli, Klebsiella pneumonia, Pseudomonas aeruginosa and Salmonella typhimurium). The activity of antibiotic Chloramphenicol, Ciprofloxacin, Tetracycline Ceftriaxone, and Gentamycin against bacteria found differences inhibition zoon. Among all antibiotic. ciprofloxacin have more activity against bacteria while Ceftriaxone have the lower activity.

Seafood is divinely rich by virtue of its high nutritional value. With the increasing knowledge of bio-functional properties associated with marine foods, utilization of the marine derivatives has been accelerated which will also prevent pollution in coastal areas. The objective of the study was to process chitosan by deacetylating chitin of crab and prawn shells. The degree of deacetylation was determined by FTIR. The fresh chitosan has been analyzed for its antioxidant and antimicrobial property that helps to determine the health benefits of the derived product. The chitosan was also incorporated in a food product to develop value added products and the shelf life of the products was evaluated. The antioxidant and antimicrobial activity of the chitosan was directly propositional to the concentration used. Value added product was prepared i.e. Cereal bar, Beetroot Squash, Orange Squash and Ice cream with three variations. 5% chitosan from crab and prawn was added in two variations and compared with the control one. The sensory evaluation was done with semi- trained panel members. The proximate analysis and quality indices was done with standard methods. The shelf life of the product was determined by the total aerobic microbial count in the period of 15 days. There was increase in the antioxidant and antimicrobial activity level in the chitosan as concentration was increased. The sensory acceptability was good in Crab based chitosan when compared with other variations. Similarly proximate and quality enhancement was observed in prawn based chitosan products than the other variations. The shelf life of the product was also increased. Hence, chitosan can be encouraged in value addition, since it acts as a functional compound and does not interferes with the sensorial factors. It also helps to improve the shelf life of the product.

The environment of Dhaka city is depraving gradually day by day because of unplanned urbanization, destruction of greeneries by increasing building and economical activities areas to meet the demand of migrated people. This scenario is enhancing the negative change in climate gradually. It is one of the main causes of Buriganga river pollution because of climate change impact. Dhaka city, a capital of Bangladesh, which largely depends on the Buriganga River’s water for drinking, fishing, carrying merchandise and transportation.. The quality of water in this river was very poor and the average DO, BOD5, COD, Nitrate and Phosphate concentration in mg/L were 1.11, 82.3, 148.45, 5.92 and 5.83 respectively. This study mainly focused the climate change impact in term of rainfall on Buriganga River and disclosed it that decreasing the rate of rainfall affect the discharge of river because of climate change and increasing the rate of waste water because of incremental economical activities in industries both affects the dilution rate of Buriganga River simultaneously and this scenario will be also big concern in future for increasing climate change impact on rainfall in Dhaka City. In this study, we also discussed about pollution status of this river and finally the way to mitigate or minimize the pollution of Buriganga River.

The degree of violence in Nigeria’s Niger Delta has become endemic and are too far-reaching to be ignored: for the inhabitants of this area, there are constant environmental hazards and security threat, The study, therefore, examined the community relations strategies used by oil companies in managing the crises in the Niger Delta. The study population comprised the community relations units of oil companies in the Niger Delta (among which Shell, Chevron and Agip were selected) and the indigenes of Omoku and Obrikom communities in Rivers State and Eruemukohwarien, Tisun and Kolokolo communities in Delta State. Both quantitative (survey) and qualitative (key informant interview and focus group discussion) methods of data collection were employed. The respondents for the survey were randomly selected while those for the interviews and focus groups were purposively selected. The study established that conflicts between oil companies and host communities had serious implications for the two parties and that the community relations strategies adopted by the selected oil companies were not adequate in preventing and resolving conflicts in the Niger Delta. That was because there was a lacuna between the strategies the oil companies believed host communities preferred for conflict resolution and the ones actually preferred by those communities.The research, therefore, recommend that to reduce conflict between oil companies and host communities in the Niger Delta, companies should be mindful of conflict propelling factors identified by the respondents and stated in the work, they should improve on their community relations strategies in order to impress the community and most importantly, they should introduce grassroots approach to the implementation of their strategies.

In a dynamic of protection of the environment and sustainable development, solar energy is one of the essential solutions to the energy problems of developing countries and to limiting greenhouse gas emissions. In this work, we compare the energy productivities of photovoltaic installations in four cities of two countries (Morocco and Burkina Faso). Government energy policies in both countries place a strong emphasis on solar photovoltaics. We then chose to make a detailed evaluation of the performances of the various photovoltaic technologies under various climatic conditions in these countries. PVsyst software is used to model the performance of a photovoltaic solar power plant connected to the 6kWc network (2kWc per technology) using three silicon-based photovoltaic technologies, namely: polycrystalline (pc-Si), monocrystalline (mc-Si) and amorphous (a-Si) in two cities per country. The comparative analysis included annual energy efficiency, performance ratio, annual energy density and system efficiency. From these performances, it can be observed that PV installations with a-Si have the highest energy yields and performance ratios (Er-Rachidia, Ouagadougou and Bobo-Dioulasso), while in Mohammedia, energy efficiency and maximum performance ratio are given by pc-Si technology. The mc-Si installation has the maximum overall efficiency of the system as well as the annual energy density in the cities selected for this study. The production of the city of Mohammedia is validated by the actual production of a 6kWc installation (2kWc per technology) made up of three mini-power plants, one with polycrystalline silicon, one with monocrystalline silicon and the other with amorphous silicon. Comparing the data validates our results.