1,371 research outputs found
The Use of Floating Solar Panels in Hot Regions Such as Iraq to Benefit in Cooling the Panels and Increasing Their Efficiency
The operating of photovoltaic panels (PV) comes with a serious contradiction. This system of solar PV panels prefers high radiation to generate electricity, but when rising their operating temperature by negative effects on their efficiency. Thus, one of the major working barriers for PV panels is overheating because of surplus solar irradiation. To get rid of the problem of overheating of the panels, we propose a new design that floats on the surface of the water floating photovoltaic panels (FPV) to take advantage of the nature of water in heat transfer, thus cooling the panels and raising the efficiency of the panels. For the purpose of this study, we proposed one of the regions of central Iraq, namely the Marsh Al-Dalmach, which is located in Wasit province, and it is one of the areas rich in solar radiation (2150 kWh/m2/year) and the length of daylight hours more 4000 operating hours during the year. After conducting a survey around the area and collecting the necessary data for use in programs such as Homer and Matlab, great results were obtained, as this design of the stations contributes to reducing temperatures and raising the efficiency of the panels from 15% to 24%
Privatization: a policy to transform and increase the production capacity of fish in Nigeria fish industries
Over 200 hatcheries of fish exist in Nigeria with at least two hatcheries in each state of the federation but unfortunately over 50 percent are either non-functional or function far below their optimum production capacities. Also about 85 percent of the non-functional hatcheries belong to the government (-either federal, state, local government or institution). The associated problems with the non-functional hatcheries include: inadequate funding, poor maintenance of hatcheries facilities, high cost of feed inputs, in adequate infrastructure, differential growth and cannibalism in catfishes which result in poor fingerling harvest, low attitude and lack of commitment to government work. Privatization/ownership options are considered the best options for this paper and clues to solve the problems mentioned above through privatization are presented. Problems with privatization and private investment are also discussed. It was advised that in case the existing hatcheries are put in to full production, the national demand for fingerlings which is placed at 4.3 billion annually could be met with ease. Fingerlings production in the hatchery as the quickest revenue yielding aspect of fish farming (with high internal rate of returns and short pay back period) capable of attracting revenue within 2-3 mouths of a breeding exercise are emphasized
Survey about impact voltage instability and transient stability for a power system with an integrated solar combined cycle plant in Iraq by using ETAP
The Analyses for power systems are more necessary for the designing, operating phase execution control and to make sure safe network operations by sufficient protection project settings. In this article, we have prepared a sufficient scientific survey about the electrical model of a 340 MW integrated solar combined cycle system (ISCCS) located in the Iraqi southern, is developed and simulation by a program called Electrical Transient Analyzer Program (ETAP) and carry out throw this program the load flow, voltage stability and short circuit analyses for this power plant with part of the national grid in Al-Basra city in an industrial region. The effect of voltage instability for the grid on system buses (load buses) of the power system is estimated. By using load flow analysis as a case study by using the Newton-Raphson algorithm, when the load buses operating at down voltage because of instability voltage of the power grid are specified and their voltages are should to improved according to given voltage limitations that are depended on buses criticality with regard to loads. The appliance on-load tap changers of the transformer and reactive power compensation are used to improve steady-state voltage stability for any instability system. The method of the optimal position for capacitor banks placement is meaning the number of capacitor banks is proposed to adding to the weak buses by using the optimal capacitor placement module of ETAP. Energy is actually required for the expansion of our country. To sustain the generation of electric power at an adequate level power system supplies power to different types of loads that are located far away from the generating plants using transmission lines
Culture potentials of climbing perch, Anabas testudineus (Bloch) under different stocking densities at semi-intensive management
Anabas testudineus was cultured at different stocking density for the period of five months from May to September. Three stocking densities such as 50,000 (Treatment-1, T1), 56,250 (Treatment-2, T2) and 62,250/ha (Treatment-3, T3) were tested with three replications. After five months rearing, the mean weights of koi were 46.74±2.59, 40.44±2.98 and 37.27±3.01 in T-1, 2 and 3, respectively. The calculated production of native koi in T1 T2 and T3 were 1,916±314, 1,774.31 ±260 and 1,431 ±297 kg/ha, respectively which were significantly different (p<0.05) from each other
Evaluation and selection of functional diversity metrics with recommendations for their use in life cycle assessments
Environmental Biolog
Epidemiology of Rotavirus and Cholera in Children Aged Less Than Five Years in Rural Bangladesh
Despite the known presence of rotavirus-associated diarrhoea in Bangladesh, its prevalence, including records of hospitalization in rural health facilities, is largely unknown. In a systematic surveillance undertaken in two government-run rural health facilities, 457 children, aged less than five years, having acute watery diarrhoea, were studied between August 2005 and July 2007 to determine the prevalence of rotavirus. Due to limited financial support, the surveillance of rotavirus was included as an addendum to an ongoing study for cholera in the same area. Rotavirus infection was detected in 114 (25%) and Vibrio cholerae in 63 (14%) children. Neither rotavirus nor V. cholerae was detected in 280 (61%) samples; these were termed ânon-rotavirus and non-choleraâ diarrhoea. Both rotavirus and cholera were detected in all groups of patients (<5 years). The highest proportion (41%; 47/114) of rotavirus was in the age-group of 6-11 months. In children aged less than 18 months, the proportion (67%; 76/114) of rotavirus was significantly (p<0.001) higher than that of cholera (16%; 10/63). By contrast, the proportion (84%; 53/63) of cholera was significantly (p<0.001) higher than that of rotavirus (33%; 38/114) in the age-group of 18-59 months. During the study period, 528 children were hospitalized for various illnesses. Thirty-eight percent (202/528) of the hospitalizations were due to acute watery diarrhoea, and 62% were due to non-diarrhoeal illnesses. Rotavirus accounted for 34% of hospitalizations due to diarrhoea. Severe dehydration was detected in 16% (74/457) of the children. The proportion (51%; 32/63) of severe dehydration among V. cholerae-infected children was significantly higher (p<0.001) compared to the proportion (16%; 18/114) of rotavirus-infected children. The study revealed that 12-14% of the hospitalizations in rural Bangladesh in this age-group were due to rotavirus infection, which has not been previously documented
Phylogenetic Findings Suggest Possible New Habitat and Routes of Infection of Human Eumyctoma
Eumycetoma is a traumatic fungal infection in tropical and subtropical areas that may lead to severe disability. Madurella mycetomatis is one of the prevalent etiologic agents in arid Northeastern Africa. The source of infection has not been clarified. Subcutaneous inoculation from plant thorns has been hypothesized, but attempts to detect the fungus in relevant material have remained unsuccessful. The present study aims to find clues to reveal the natural habitat of Madurella species using a phylogenetic approach, i.e. by comparison of neighboring taxa with known ecology. Four species of Madurella were included in a large data set of species of Chaetomium, Chaetomidium, Thielavia, and Papulaspora (n = 128) using sequences of the universal fungal barcode gene rDNA ITS and the partial LSU gene sequence. Our study demonstrates that Madurella species are nested within the Chaetomiaceae, a family of fungi that mainly inhabit animal dung, enriched soil, and indoor environments. We hypothesize that cattle dung, ubiquitously present in rural East Africa, plays a significant role in the ecology of Madurella. If cow dung is an essential factor in inoculation by Madurella, preventative measures may involve the use of appropriate footwear in addition to restructuring of villages to reduce the frequency of contact with etiologic agents of mycetoma. On the other hand, the Chaetomiaceae possess a hidden clinical potential which needs to be explored
Denial at the top table: status attributions and implications for marketing
Senior marketing management is seldom represented on the Board of Directors nowadays, reflecting a deteriorating status of the marketing profession. We examine some of the key reasons for marketingâs demise, and discuss how the status of marketing may be restored by demonstrating the value of marketing to the business community. We attribute marketingâs demise to several related key factors: narrow typecasting, marginalisation and limited involvement in product development, questionable marketing curricula, insensitivity toward environmental change, questionable professional standards and roles, and marketingâs apparent lack of accountability to CEOs. Each of these leads to failure to communicate, create, or deliver value within marketing. We argue that a continued inability to deal with marketingâs crisis of representation will further erode the status of the discipline both academically and professionally
The quark part of the non-forward BFKL kernel and the ``bootstrap'' for the gluon Reggeization
We calculate the quark part of the kernel of the generalized non-forward BFKL
equation at non-zero momentum transfer in the next-to-leading logarithmic
approximation. Along with the quark contribution to the gluon Regge trajectory,
this part includes pieces coming from the quark-antiquark production and from
the quark contribution to the radiative corrections in one-gluon production in
the Reggeon-Reggeon collisions. The results obtained can be used for an
arbitrary representation of the colour group in the channel. Using the
results for the adjoint representation, we demonstrate explicitly the
fulfillment of the ``bootstrap'' condition for the gluon Reggeization in the
next-to-leading logarithmic approximation in the part concerning the quark
contribution.Comment: 26 pages, LaTeX, uses axodraw.sty; revised final comment; to appear
on Phys. Rev.
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