British journal of applied science & technology最新文献

{"title":"Maximization of Transfer Ratio and Minimization of Harmonics in Three Phase AC/AC Matrix Converter","authors":"Raheel Muzzammel, Umair Tahir","doi":"10.9734/BJAST/2017/33416","DOIUrl":"https://doi.org/10.9734/BJAST/2017/33416","url":null,"abstract":"Energy saving and different working voltage applications are widely employing matrix converters. Matrix converters are used to convert three phase AC input voltages to three phase AC output voltages of required magnitude and frequency. Pulse width modulation is a technique used for converting three phase AC input to three phase AC output. In this research paper, pulse width modulation based matrix converter will be designed to acquire voltage of desired magnitude and frequency. Voltage transfer ratio will be maximized in this technique so that any desired voltage magnitude could be achieved. Secondly, harmonics will be made reduced in this design. Simulations will be performed in Matlab and characteristics of output waveform will be observed with respect to characteristics of input waveforms.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":"21 1","pages":"1-20"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49145716","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Computational Study of Aerodynamic Flow over NACA 4412 Airfoil","authors":"Moses Omolayo Petinrin, Vincent A. Onoja","doi":"10.9734/BJAST/2017/31893","DOIUrl":"https://doi.org/10.9734/BJAST/2017/31893","url":null,"abstract":"The lift and drag coefficient plots for any airfoil provides a means for measuring its aerodynamic characteristics. These are very useful in deciding if a particular airfoil is appropriate for any particular application area. This study computationally predicts how the lift coefficient, drag coefficient and drag polar derived for the aerodynamic flow over the NACA 4412 airfoil vary with angles of attack. The effect of varying Reynolds number on the aerodynamic characteristics was also investigated. The finite-volume based computational fluid dynamics code; ANSYS Fluent was used to solve the continuity equation, the Reynolds Averaged Navier-Stokes equation and the turbulence transport equations governing the flow. For the range of Reynolds number considered, flow was taken as incompressible, steady and two-dimensional. Simulations were run for angles of attack ranging from -10° to 18° with an interval of 2° and for a Reynolds number range of 1.0 x 10 6 to 13.0 x 10 6 . Results at a given Reynolds number revealed a steady variation between lift coefficient and angle of attack within the pre-stall region and a gradually increasing curve for the drag coefficients. A constant stalling angle at 14° w ith gradually increasing value for the maximum lift coefficient was recorded as the Reynolds number increased. The drag polar was also found to be constant at 6° for all the ranges of R eynolds number. The results obtained showed that numerically solving for flow problems is a valid approach for obtaining the aerodynamic characteristics of an airfoil since the results were compared with data from wind tunnel tests.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":" ","pages":"1-11"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48765887","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Spatial and Temporal Trends of Monthly, Seasonal and Annual Precipitation in Districts of Jharkhand in India","authors":"S. Mali, B. Das, J. S. Choudhary, An Singh, B. Bhatt","doi":"10.9734/BJAST/2017/33502","DOIUrl":"https://doi.org/10.9734/BJAST/2017/33502","url":null,"abstract":"Characterization of spatial variability and temporal trends in precipitation in a changing climate is vital to assess climate-induced changes to support adequate agricultural planning and water resources management strategies for the future. In this context, spatial and temporal variability in the precipitation over Jharkhand state in Eastern plateau and hill region is investigated. Spatial distribution of precipitation was mapped using ‘ordinary kriging’ geostatistical interpolation technique. A comprehensive precipitation trend and periodic analysis at the monthly and seasonal scale on a 40 year data series (1975-2014) for 18 locations in Jharkhand are presented using MannKendall and Sen’s slope methods. The seasonal and annual precipitation showed large spatial variability across the Jharkhand. Although, the spatial distribution of monsoon and annual precipitation are roughly similar, annual precipitation varied considerably in space due to the variations induced by pre-monsoon and winter precipitation. The statistical analysis revealed predominantly decreasing trends, both at the annual and seasonal scale. July precipitation showed significantly decreasing trend (-3.17 to -6.21 mm/year) in large number of districts (15), while the Original Research Article Mali et al.; BJAST, 20(6): 1-17, 2017; Article no.BJAST.33502 2 trend in May and other ‘monsoon’ months was not significant. Over the reference period, the negative trends in monsoon, winter and annual precipitation were significant for 61, 67 and 50% of the total districts analyzed with rate of decrease for monsoon and annual precipitation in the range of -5.3 to -13.0 and -5.3 to -15.9 mm/year, respectively. In view of the rainfall dependence of the agriculture in the state and decreasing trends of precipitation, the information presented in this paper can supports further climate change risk assessment and vulnerability adaptation planning.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":"20 1","pages":"1-17"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"71185881","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Competitive Adsorption of Cu(II) and Zn(II) from Binary Heavy Metal Solutions by Coffee Waste","authors":"Lovell Agwaramgbo, Simone Zulpo, S. Lira","doi":"10.9734/BJAST/2017/31336","DOIUrl":"https://doi.org/10.9734/BJAST/2017/31336","url":null,"abstract":"Adsorption process has been proven to be one of the best water treatment technologies globally and activated carbon is undoubtedly considered a universal adsorbent for the removal of a variety of pollutants from water. However, widespread use of commercial activated carbon is often times restricted due to its higher costs. Attempts have been made to develop inexpensive adsorbents utilizing numerous agro-industrial and municipal waste materials. Use of waste materials as low-cost adsorbents is attractive due to their contribution in the reduction of costs or waste disposal, therefore, contributing to environmental protection. In this article was investigated the adsorption behavior of coffee waste when exposed to both single and binary metal component solutions under varying initial concentrations (1000, 500, and 250 ppm) and contact time (3 and 24 hrs.) It is evident from the literature that various low-cost adsorbents have shown good potential for the removal of various pollutants. However, there are few issues and drawbacks on the use of low-cost adsorbents in water treatment that have been discussed in this paper. Additionally, more research is needed to find the practical utility of low-cost adsorbents such as waste coffee on a commercial scale. After the exposure times, the residual concentrations of each heavy metal was determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES), using EPA Method 6010. Results suggest that the percentage of adsorption of Cu and Zn decreases as the initial metal concentration increases. The coffee waste also has a higher affinity for Cu than Zn ion. The percentages for metal ion removal from the single metal solution are 250 ppm (73.47%), 500 ppm (46.45%), 1000 ppm (27.69%) for copper and 250 ppm (55.08%), 500 ppm (32.78%), and 1000 ppm (21.22%) for zinc. For the competitive metal removal from the binary Cu-Zn solutions, the percentages are 125 ppm (85.67%), 250 ppm (68.93%), and 500 ppm (46.62%) for copper and 125 ppm (49.67%), 250 ppm (7.73%), and 500 ppm (4.59%) for zinc, respectively.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":" ","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42762228","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A New Approach of Content Based Image Retrieval Using Color and Texture Features","authors":"Hossain, Islam","doi":"10.9734/BJAST/2017/33326","DOIUrl":"https://doi.org/10.9734/BJAST/2017/33326","url":null,"abstract":"The dramatic development of","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":"21 1","pages":"1-16"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43107198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Critical Analysis of Polycyclic Aromatic Hydrocarbons Ring Size Distribution in Marshy Soils and Sediments in Warri City and Its Environs, Southern Nigeria","authors":"I. Agbozu, A. V. Bayowa, O. Oghama","doi":"10.9734/BJAST/2017/32126","DOIUrl":"https://doi.org/10.9734/BJAST/2017/32126","url":null,"abstract":"This work was carried out in collaboration between all authors. Author IEA designed and supervised the study and wrote the protocol. Author AVB carried out and managed the analyses of the study. Authors IEA and AVB managed the literature searches while author OEO performed the statistical analyses. Authors IEA and OEO wrote the first draft of the manuscript. All authors read and approved the final manuscript. ABSTRACT This study was carried out to analyze the ring size distribution of Polycyclic Aromatic Hydrocarbons (PAHs) in marshy soils and sediment samples in Warri City, Southern Nigeria. The samples were collected during dry and rainy seasons from four locations within Warri and a control location in Agbarho, 20km away. Levels of 16 priority PAHs listed in United States Environmental Protection Agency (USEPA) were determined using Gas Chromatography coupled with Flame Ionization detector (GC-FID). This study was carried from January to March and June to August, representing the dry and wet seasons respectively. It was observed that PAHs concentration was generally higher in dry than rainy seasons for soil and sediment samples. Furthermore, ring size analysis revealed that for soils, two to three-ringed as well as four-ringed PAHs were more predominant in Ugboroke location, five-ringed PAHs in Okotie and six-ringed PAHs in Ogunu location. Overall, five-ringed PAHs were more predominant in Okotie location in the dry season. However, for sediments, two to three-ringed as well as four-ringed PAHs were more predominant in Okotie location, five-ringed PAHs in Ogunu and six-ringed PAHs in Ugboroke location. Overall, two to three-ringed PAHs were more predominant in Okotie location in the dry season for sediment samples.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":"20 1","pages":"1-16"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43704441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Analysis of Reconfigurable Polarization Antenna as an EMI Sensor","authors":"K. Mamta, R. Singh","doi":"10.9734/BJAST/2017/31798","DOIUrl":"https://doi.org/10.9734/BJAST/2017/31798","url":null,"abstract":"Electromagnetic Interference (EMI) is of great concern in the present time of modern electronic systems. EMI measurement requires using a sensor to receive the radiation from the equipment in a suitable test environment. Antenna Factor decides the performance of the sensor. Finite Difference Time Domain (FDTD) numerical method has been used to predict the performance of antenna used as EMI sensor.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":" ","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44602210","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the Riesz Integral Representation of Additives Set-Valued Maps (I)","authors":"Lakmon Kodjovi, S. Kenny, Ayassou Emmanuel, Tchariè Kokou","doi":"10.9734/BJAST/2017/30901","DOIUrl":"https://doi.org/10.9734/BJAST/2017/30901","url":null,"abstract":"In this paper we generalize the Riesz integral representation for continuous linear maps associated with additive set-valued maps with values in the set of all closed bounded convex non-empty subsets of any Banach space. We deduce the Riesz integral representation results for set-valued maps, for vector-valued maps of Diestel-Uhl and for scalar-valued maps of Dunford-Schwartz.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":" ","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46786556","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Evaluation of Some Nutrient Contents and Antifungal Properties of Ground Musa paradisiaca (Plantain) Peels and Leaves","authors":"Anthony Cemaluk C. Egbuonu, Wisdom O. Nneji, Chimnonye A. Ukasoanya","doi":"10.9734/bjast/2017/28393","DOIUrl":"https://doi.org/10.9734/bjast/2017/28393","url":null,"abstract":"Musa paradisiaca (plantain) fruit peels and the plant leaves may have some nutrients and antifungal properties. Thus, millimeter, mm) against Candida albicans, however, the activity of the ethanol extract of the leaves (15.67±0.58) was higher (p<0.05) than that of the ethanol extract of the peels and the aqueous extract of the peels and leaves. The difference in activity against C. albicans between the samples extracts in terms of either the same or the different extracting solvent was significant (p<0.05) but the overall difference between the samples compared to the extracting solvents (±0.67) was the same hence non-significant (p>0.05). A similar trend was recorded for the activity of the ethanol and aqueous extracts of the peels and leaves against P. notatum . Thus, the plantain peels and leaves could be alternative source for vitamin C. The extracts (aqueous and ethanol) had activity against C. albicans and P. notatum hence may be useful in managing such pathogen-induced ailments. Overall negligible difference in activity against either C. albicans or P. notatum in terms of samples and the extracting solvents was suggested and this may be an underlying useful trend for comparing the overall antimicrobial activity of different samples and solvents, hence warrants a follow up.","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":" ","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46814396","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Geochemical Characterization and Protolith of the Migmatite-Gneisses of Tandama Area, Katsina State, NW Nigeria","authors":"Idzi Alaku, O. Moshood, A. Agbor, A. Amos","doi":"10.9734/BJAST/2017/30117","DOIUrl":"https://doi.org/10.9734/BJAST/2017/30117","url":null,"abstract":"Migmatite-gneisses, which include migmatite, granite gneiss, and augen gneiss, underlie more than 70% of Tandama area, in North-western Nigeria. They are associated with schists, and are intruded by granites and pegmatites. These rocks are thought to have undergone a reworking during the Pan-African Orogeny. The aim of this research is to present results of geochemical investigation of Migmatite-gneiss Complex in the study area with a view to determine their geochemical characteristics and petrogenesis. Whole rock geochemical analyses have been used to evaluate the characteristics, petrogenesis and mode of emplacement of the protoliths. Geochemically, these rocks show granitic affinities. They are metaluminous to weakly peraluminous I-type, with S-type characteristic, magnesian to ferroan and alkali calcic and calcic. The protoliths could have been derived from the partial melting of tonalitic to granodioritic crustal rocks at low pressure, thus, producing metaluminous to slightly peraluminous high-silica, ferroan, alkali-calcic to calc-alkali melts, which is why it has some S-type character. These varying features are an indication that the protoliths are derived from mainly crustal melt mingled with mantle-derived component. The varying REEs and trace elements pattern displayed by the rocks is typical signature of arc rocks or continental crustal materials: the LREEs and LILE enrichment along with Rb, K, Pb, and negative Nb, Ta, Ti are evident of this signature. The incompatible trace elements show similarity to those of continental crustal rocks as indicated by the ratios in Th/U (2.21 12.4), Th/Yb (2.60 – 90.95), Ta/Yb (0.03 - 1.43), Ce/Pb (mainly 0.30 – 29.23) and high Ba/Nb (8.56 – 2402), the values of Sr/Y are generally<100, which is an indication of subduction-related rocks,the trend in Sr/Y ratio relative to Y contents in the rocks reflects essentially two types of felsic protolith namely crustal melts and slab melts. Similarly, the magnesian characteristic indicates close affinity to relatively hydrous, oxidizing melts, which is broadly typical of settings related to subduction. The high-K nature is characteristics of crustal rocks derived from remelting and differentiation of arc-accretionary complex crust. The rare earth element (REE) distribution shows that the migmatite-gneisses are enriched in the lighter rare earth elements (LREE) Sm, Pr, Nd, La and Ce, in that order of increasing abundance, with average values of 4.81 ppm, 7.90 ppm, 27.50 ppm, 38.44 ppm, 68.22ppm, respectively; and relatively depleted in the heavy rare earth elements (HREE) Lu, Tm, Tb, Ho, Yb and Er, with average values ranging 0.28 ppm, 0.30 ppm, 0.58 ppm, 0.65ppm, 1.91 ppm and 1.88 ppm respectively, and they exhibit negative EU anomaly, indicating that the rocks are highly fractionated. REE-chondrite normalized spider plot and plots in the chemical discrimination diagrams including the Y versus Nb plot, show that the protoliths were derived from partial melting","PeriodicalId":91221,"journal":{"name":"British journal of applied science & technology","volume":"20 1","pages":"1-18"},"PeriodicalIF":0.0,"publicationDate":"2017-01-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46853171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}