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Performance Analysis of ZF and RZF in Low-Resolution ADC/DAC Massive MIMO Systems
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作者 Talha Younas Shen Jin +4 位作者 Muluneh Mekonnen Gao Mingliang Saqib Saleem Sohaib Tahir Mahrukh Liaqat 《China Communications》 SCIE CSCD 2024年第8期115-126,共12页
Large number of antennas and higher bandwidth usage in massive multiple-input-multipleoutput(MIMO)systems create immense burden on receiver in terms of higher power consumption.The power consumption at the receiver ra... Large number of antennas and higher bandwidth usage in massive multiple-input-multipleoutput(MIMO)systems create immense burden on receiver in terms of higher power consumption.The power consumption at the receiver radio frequency(RF)circuits can be significantly reduced by the application of analog-to-digital converter(ADC)of low resolution.In this paper we investigate bandwidth efficiency(BE)of massive MIMO with perfect channel state information(CSI)by applying low resolution ADCs with Rician fadings.We start our analysis by deriving the additive quantization noise model,which helps to understand the effects of ADC resolution on BE by keeping the power constraint at the receiver in radar.We also investigate deeply the effects of using higher bit rates and the number of BS antennas on bandwidth efficiency(BE)of the system.We emphasize that good bandwidth efficiency can be achieved by even using low resolution ADC by using regularized zero-forcing(RZF)combining algorithm.We also provide a generic analysis of energy efficiency(EE)with different options of bits by calculating the energy efficiencies(EE)using the achievable rates.We emphasize that satisfactory BE can be achieved by even using low-resolution ADC/DAC in massive MIMO. 展开更多
关键词 low-bit analog-digital converter massive(multiple-input-multiple-output)MIMO minimum mean square error(MMSE) regularized zero forcing zero forcing
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Comparative Analysis on Road Users’Cost Using HDM-4 Software and Manual Technique:A Case of Addis Ababa-Adama Expressway
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作者 Biniyam Kebebew Emer T.Quezon 《Journal of Management Science & Engineering Research》 2022年第1期64-75,共12页
Continuous changes in vehicle technology,road condition,traffic compo­sitions initiate the change or updating of road users’cost models.So that it needs to practice a continuous revision or update periodically f... Continuous changes in vehicle technology,road condition,traffic compo­sitions initiate the change or updating of road users’cost models.So that it needs to practice a continuous revision or update periodically for realistic estimation of costs and benefits.This paper presented the relationship and comparison between road users’cost along Addis Ababa-Adama newly constructed expressway using the Highway Development and Management(HDM-4)Software and manually using formulations developed in the Por­tuguese model.The method started with data collection.All input data were collected from primary and secondary sources.The primary data utilized an interview,and secondary data were sourced out from pertinent documents,both published and unpublished.More data were gathered that related to vehicles.The vehicles using the road are classified based on the manual from the Ethiopian Road Authority as cars,utilities,small bus,large bus,small truck,medium truck,heavy truck,and truck trailer.The collected data have been input into the HDM-4 interface;the output of the analysis was vehicle operating costs,travel time,and road users’cost as a summation.Using manual technique and HDM-4 Software,Birr 128.62/km/vehicle and Birr 139.23/km/vehicle,respectively,were found from road users’costs analysis.The result shows the difference of Birr 10.61.Also,the correlation coefficient of 0.75 is determined,which shows that the two results of road users’costs are highly related.As a result,the study reveals that the appli­cation of HDM-4 Software and the manual technique formulations from the Portuguese model can be adopted interchangeably to calculate Road Users’Cost of road sections in Ethiopia.Hence,the study results are expected to be an eye-opener for a future similar project by the concerned agencies. 展开更多
关键词 Cost-benefits HDM-4 Software Portuguese RCU model Road users’cost
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MultiDMet: Designing a Hybrid Multidimensional Metrics Framework to Predictive Modeling for Performance Evaluation and Feature Selection
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作者 Tesfay Gidey Hailu Taye Abdulkadir Edris 《Intelligent Information Management》 2023年第6期391-425,共35页
In a competitive digital age where data volumes are increasing with time, the ability to extract meaningful knowledge from high-dimensional data using machine learning (ML) and data mining (DM) techniques and making d... In a competitive digital age where data volumes are increasing with time, the ability to extract meaningful knowledge from high-dimensional data using machine learning (ML) and data mining (DM) techniques and making decisions based on the extracted knowledge is becoming increasingly important in all business domains. Nevertheless, high-dimensional data remains a major challenge for classification algorithms due to its high computational cost and storage requirements. The 2016 Demographic and Health Survey of Ethiopia (EDHS 2016) used as the data source for this study which is publicly available contains several features that may not be relevant to the prediction task. In this paper, we developed a hybrid multidimensional metrics framework for predictive modeling for both model performance evaluation and feature selection to overcome the feature selection challenges and select the best model among the available models in DM and ML. The proposed hybrid metrics were used to measure the efficiency of the predictive models. Experimental results show that the decision tree algorithm is the most efficient model. The higher score of HMM (m, r) = 0.47 illustrates the overall significant model that encompasses almost all the user’s requirements, unlike the classical metrics that use a criterion to select the most appropriate model. On the other hand, the ANNs were found to be the most computationally intensive for our prediction task. Moreover, the type of data and the class size of the dataset (unbalanced data) have a significant impact on the efficiency of the model, especially on the computational cost, and the interpretability of the parameters of the model would be hampered. And the efficiency of the predictive model could be improved with other feature selection algorithms (especially hybrid metrics) considering the experts of the knowledge domain, as the understanding of the business domain has a significant impact. 展开更多
关键词 Predictive Modeling Hybrid Metrics Feature Selection Model Selection Algorithm Analysis Machine Learning
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Non-timber forest products and household incomes in Bonga forest area,southwestern Ethiopia 被引量:5
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作者 Ermias Melaku Zeleke Ewnetu Demel Teketay 《Journal of Forestry Research》 SCIE CAS CSCD 2014年第1期215-223,共9页
We identified the major non-timber forest products (NTFPs), their contributions to household incomes, and the determinants influenc-ing engagement of households in using NTFPs in the Bonga forest area of Gimbo and D... We identified the major non-timber forest products (NTFPs), their contributions to household incomes, and the determinants influenc-ing engagement of households in using NTFPs in the Bonga forest area of Gimbo and Decha Districts of Kaffa Zone, southwest Ethiopia. Six Kebeles (the lowest administrative unit in Ethiopia) were sampled from two Districts and 150 households were randomly sampled using propor-tional-to-size techniques based on the number of farm households in each Kebele. Secondary data were collected from and focus group discussions were conducted with selected individuals. The farmers diversified liveli-hood activities such as crop and livestock production, collection of NTFPs and off-farm activities. NTFPs played a significant role in household incomes. The contribution from the major NTFPs (forest coffee, honey and spices) accounted for 47% of annual household in-come. The role of NTFPs was influenced by a number of factors. Vari-ables including being native to the area (+), total land holding (+), pos-session of livestock (+) and access to extension (+) significantly affected forest coffee production. Age of household head (-), land holding (+) and distance of the market from the residence (-) significantly affected honey production. Size of landholding (+), distance to market (-) and distance of the forest from the residence (-) were significant variables determining the NTFP incomes derived by the households. Attention is needed in the design of policies and strategies for the well-being of households to the contribution of NTFPs to local incomes and the variables that affect the collection of NTFPs must be considered. 展开更多
关键词 Bonga forest determinants of NTFP collection household income livelihood activities NTFPS
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Can the venerated silk be the next generation nanobiomaterialfor biomedical device designing, regenerative medicine and drugdelivery? Prospects and hitches 被引量:2
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作者 Rocktotpal Konwarh 《Bio-Design and Manufacturing》 SCIE CSCD 2019年第4期278-286,共9页
Of late, the relevance of silk in a myriad of material science and biotechnological realms has been realized, as attested by the incessantly clambering number of reports and patents in the scienti fic repositories. Th... Of late, the relevance of silk in a myriad of material science and biotechnological realms has been realized, as attested by the incessantly clambering number of reports and patents in the scienti fic repositories. The write-up is geared off with a scrutiny into the pertinence of the basic nano-structural features of silk, christened as the ‘queen of textile’ for exemplary bioengi- neering applications including designing and fabrication of devices for micro fluidics, opto fluidics, chemo/bio sensing, etc. Then, the major thrust of this short review is directed towards comprehending the prospects of using silk-based biomaterials (e.g. sca ffolds, electrospun membranes, films, hydrogels, bioinks) for tissue engineering and regenerative medicine as well as targeted delivery of various biomolecular cargoes/therapeutic agents, etc., as vouched by few avant-garde endeavours of the recent years. The write-up is entwined with a discussion on the various factors that could plausibly hinder the realization of silk as the next-generation nanobiomaterial, suggestions for some approaches to dodge and deal with the practical snags and what lies ahead! 展开更多
关键词 Drug delivery MICROFLUIDICS Nanobiomaterial Regenerative medicine SILK Tissue engineering
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Optimization, Kinetics, and Equilibrium Studies on the Removal of Lead(Ⅱ) from an Aqueous Solution Using Banana Pseudostem as an Adsorbent 被引量:2
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作者 Shridhar S. Bagali Bychapur S. Gowrishankar Aashis S. Roy 《Engineering》 SCIE EI 2017年第3期409-415,共7页
Natural adsorbents such as banana pseudostem can play a vital role in the removal of heavy metal elements from wastewater. Major water resources and chemical industries have been encountering difficulties in re- movin... Natural adsorbents such as banana pseudostem can play a vital role in the removal of heavy metal elements from wastewater. Major water resources and chemical industries have been encountering difficulties in re- moving heavy metal elements using available conventional methods. This work demonstrates the potential to treat various effluents utilizing natural materials. A characterization of banana pseudostem powder was performed using environmental scanning electron microscopy (ESEM) and Fourier-transform infrared (FTIR) spectroscopy before and after the adsorption of lead(Ⅱ). Experiments were carried out using a batch process for the removal of lead(Ⅱ) from an aqueous solution. The effects of the adsorption kinetics were studied by altering various parameters such as initial pH, adsorbent dosage, initial lead ion concentration, and contact time. The results show that the point of zero charge (PZC) for the banana pseudostem powder was achieved at a pH of 5.5. The experimental data were analyzed using isotherm and kinetic models. The adsorption of lead(Ⅱ) onto banana pseudostem powder was fitted using the Langmuir adsorption isotherm. The adsorp- tion capacity was found to be 34.21 mg·g-1, and the pseudo second-order kinetic model showed the best fit. The optimum conditions were found using response surface methodology. The maximum removal was found to be 89%. 展开更多
关键词 Banana pseudostem LEAD ISOTHERM Adsorption Response surface methodology
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Synthesis, Characterization and Antibacterial Activities of Polydentate Schiff Bases, Based on Salicylaldehyde 被引量:1
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作者 Yosef Bayeh Fekiya Mohammed +3 位作者 Mamo Gebrezgiabher Fikre Elemo Mesfin Getachew Madhu Thomas 《Advances in Biological Chemistry》 2020年第5期127-139,共13页
<span style="font-family:Verdana;">Three Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;&quo... <span style="font-family:Verdana;">Three Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, L</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> were synthesized by condensing salicylalde</span><span style="font-family:Verdana;">hyde with 4-aminoantipyrine, ethylendiamine and 2-aminophenol respec</span><span style="font-family:Verdana;">tively and subsequently characterized by various physicochemical investigations. All the three compounds were screened for their </span><i><span style="font-family:Verdana;">In-vitro</span></i><span style="font-family:Verdana;"> antibacterial activity against two gram positive bacteria, </span><i><span style="font-family:Verdana;">Staphylococcus aureus</span></i><span style="font-family:Verdana;"> (S.A), </span><i><span style="font-family:Verdana;">Staphylococcus epidermidis</span></i><span style="font-family:Verdana;"> (S.E) and two gram negative bacteria </span><i><span style="font-family:Verdana;">Klebsiella</span></i><span><span><i><span style="font-family:""> </span></i></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><i><span style="font-family:Verdana;">pneumoniae</span></i></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;"> (K.P) and </span><i><span style="font-family:Verdana;">Pseudomonas aeruginosa </span></i><span style="font-family:Verdana;">(</span></span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">P.</span></span></span><span><span><span style="font-family:""><span style="font-family:Verdana;">A) by agar diffusion method. On comparing the results obtained with the activity of commercially available antibiotics such as Ciprofloxacin and Chloramphenicol, the newly synthesized compounds showed comparable antibacterial activities. The solvent methanol exhibit activity against all bacterial species with IZs ranging from 8 ± 0.25 to 17 ± 0.29 mm while the standard antibiotics Ciprofloxacin and Chloramphenicol exhibited an activities with IZs varying from 21.3 ± 0.31 to 28.3 ± 0.32 and 26.3 ± 0.24 mm to 32.3 ± 0.23 mm, respectively. However, the newly synthesized Schiff bases L</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;">, L</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> and L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed IZs ranging from 7.4 ± 0.23 to 32.5 ± 0.14, 3 ± 0.57 to 12 ± 0.28 and 10 ± 0.20 to 32 ± 0.36 respectively. Among the Schiff bases, L</span><sub><span style="font-family:Verdana;">3</span></sub><span style="font-family:Verdana;"> showed the activity (32 ± 0.36) against S.E and P.A </span><span style="font-family:Verdana;">which is higher than the activity of standard antibiotics Ciprofloxacin and</span><span style="font-family:Verdana;"> Chloramphenicol against the same bacterial strains. The results obtained revealed that all the synthesized Schiff bases exhibit appreciable antibacterial activity against all the bacteria species which potentially makes them, to apply as wide range antibacterial drugs, after further </span><i><span style="font-family:Verdana;">in-vivo</span></i><span style="font-family:Verdana;"> cytotoxicity investigations. Their activity can also be further modified by changing the functionality of precursors for Schiff base condensation.</span></span></span></span> 展开更多
关键词 Schiff Bases Salicyaldehyde Antibacterial Activity In-Vitro
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The Distribution of Prime Numbers and Finding the Factor of Composite Numbers without Searching
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作者 Dagnachew Jenber 《Advances in Pure Mathematics》 2015年第6期338-352,共15页
In this paper, there are 5 sections of tables represented by 5 linear sequence functions. There are two one-variable sequence functions that they are able to represent all prime numbers. The first one helps the last o... In this paper, there are 5 sections of tables represented by 5 linear sequence functions. There are two one-variable sequence functions that they are able to represent all prime numbers. The first one helps the last one to produce another three two-variable linear sequence functions. With the help of these three two-variable sequence functions, the last one, one-variable sequence function, is able to set apart all prime numbers from composite numbers. The formula shows that there are infinitely many prime numbers by applying limit to infinity. The three two-variable sequence functions help us to find the factor of all composite numbers. 展开更多
关键词 The nth SEQUENCE of an ARITHMETIC SEQUENCE NUMBER of Elements of the Set SEQUENCE FUNCTIONS
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Inter-Basin Groundwater Transfer and Multiple Approach Recharge Estimation of the Upper Awash Aquifer System
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作者 Behailu Berehanu Tilahun Azagegn +1 位作者 Tenalem Ayenew Marco Masetti 《Journal of Geoscience and Environment Protection》 2017年第3期76-98,共23页
Multiple approaches have been used to estimate groundwater recharge in the Upper Awash river basin. The amount of recharge reaching the Upper Awash aquifer system from the Blue Nile sub-basins is also estimated. Water... Multiple approaches have been used to estimate groundwater recharge in the Upper Awash river basin. The amount of recharge reaching the Upper Awash aquifer system from the Blue Nile sub-basins is also estimated. Water Balance, Chloride Mass Balance and HYDRUS 1D infiltration model are used to estimate recharge. A total of 29 sites were selected for the HYDRUS 1D multiple “at point” recharge simulations. Base Flow Separation (BFS) methods, using both River Analysis Package software Version 3.0.3 and Excel-based Time Plot program are also used as a proxy for recharge. Besides, overlay analysis in Processing MODFLOW, ArcGIS, and SURFER environments has been done to thoroughly consider spatial heterogeneity between any two point estimates and appreciate the effect of lineament density, topography, slope and major urbanized land on pattern of spatial distribution of recharge. Because of differences inherent in the assumptions and datasets used, the various methods employed give wide range of differences in recharge estimates. Recharge estimated for the Upper Awash basin ranges from 51.5 mm/year to 157 mm/year and for the two southern left-bank sub-basins of the Middle Blue Nile basin (Mugher and Jema) ranges from 86 mm/year to 239 mm/year. Consequently, annual average volumetric recharge in the Upper Awash and annual groundwater flux from portion of the Blue Nile sub basins to the Upper Awash aquifer system are estimated to be 983 Mm3 and 365 Mm3 respectively. The significant flux joining the Upper Awash groundwater system from part of the Middle Blue Nile basin, which is almost 37% of the total annual recharge to the Upper Awash basin makes this part of the Middle Blue Nile basin an important recharge zone for the Upper Awash groundwater. Estimating recharge using integrated approaches was found to be useful to identify range of plausible recharge rates in the two basins. Besides, the new methodological approach of superimposing recharge governing factors on interpolation of point recharge estimates helps to produce physical based spatial distribution of recharge. 展开更多
关键词 UPPER Awash RECHARGE Inter Basin GROUNDWATER Flow MULTIPLE RECHARGE ESTIMATION
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Chemical Composition of Industrial Effluents and Their Effect on the Survival of Fish and Eutrophication of Lake Hawassa, Southern Ethiopia
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作者 Behailu Berehanu Bekele Lemma Yosef Tekle-Giorgis 《Journal of Environmental Protection》 2015年第8期792-803,共12页
Growing trends in industrialization in Ethiopia have raised concerns about pollution of water bodies particularly of lakes. This study was therefore conducted to 1) characterize the chemical contents of major industri... Growing trends in industrialization in Ethiopia have raised concerns about pollution of water bodies particularly of lakes. This study was therefore conducted to 1) characterize the chemical contents of major industrial effluents (namely textile ceramic and soft drink factories) that reached Lake Hawassa and 2) investigate the effects of the above mentioned factory effluents on survival of larvae fish and growth of algae. Effluent samples were collected from the outlet lagoons of each factory in December, 2009. Then, effluent samples were analyzed for total N, NO3-N, NH4-N, S2-, , , COD, total dissolved solids (TDS) and heavy metals at the federal Environmental Protection Agency (EPA) Laboratory, Addis Ababa. The experiments on the impact of effluents on survival of fish larvae and growth of algae were conducted using six concrete paved ponds (with different concentration of effluent). The results of chemical analysis showed that textile effluent had high COD (nearly 3 times higher), TDS (19 times higher) as well as (39 times higher) than the maximum permissible limits (MPL) set by Environmental Protection Authority (EPA). Among heavy metals, Zn and Fe of textile effluent were much higher (41 and 1.5 times higher, respectively) than the MPL set by EPA. Ceramic effluent also contained high concentration of (24.5 times), S2-, (2 times) and Zn (14 times) exceeding the limit of EPA. Regarding soft drink factory, high values of COD, and Zn were found in the effluent than the limit specified by EPA. The biological treatment lagoons of the respective source were not effective since the effluents were taken from the last treatment lagoon (outlet lagoon) and some of the measured parameters were higher than MPL. Results of the pond experiment showed that 5%, 10% and 20% concentration levels of the HTF effluent killed significantly high proportion of the fry (65%, 86.8% and 88.7%, respectively). In contrast, fry mortality in ceramic and soft drink effluent treatments, even at 10 and 20% concentration levels, stayed nearly below 10%, which were not far off from the mortality of the control groups. Algal biomass in the treated ponds varied with the type of effluent treatment and concentration level. Compared with the first day, chlorophyll “a” concentration measured on the 7th day had increased by 51%, 48%, 74%, 27% and 31% at 0%, 1%, 5%, 10% and 20% concentrations, respectively of textile effluent. The 5% treatment level of textile effluent caused the highest rate of algal growth above the growth rate observed in the control pond, but further increased in concentration to 10% and 20% resulted in a lower growth of algae than in the control pond. Therefore, textile effluent may boost up algae growth at lower concentrations (~5%) but at higher concentration levels its toxic effect may become inhibitory. Regarding the effluent of soft drink factory, algal growth progressively diminished with increasing concentration of the effluent. The overall change (between initial and day 7) in chlorophyll “a” concentration was highest in the control pond (36.2%) and decreased with increasing effluent concentration (1% to 20%) from 21.7% to -9.4%. On the other hand, algal growth under ceramic effluent treatment was comparable with that observed in the control pond. 展开更多
关键词 LAKE Hawassa Industrial EFFLUENT FRY Mortality CHLOROPHYLL “a” ALGAL Growth EUTROPHICATION
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Ferromagnetism in Diluted Magnetic Semiconductor (Ga,Mn)As Quantum Wires and Quantum Wells under the Influence of Photo-Excitation and Spin Wave Scattering
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作者 Chernet Amente Keya Dharamvir 《Journal of Modern Physics》 2013年第12期1563-1568,共6页
We present a theoretical investigation of the influence of photo-excitation and spin wave scattering on magnetization of the (Ga,Mn)As diluted magnetic semiconductor (DMS) quantum wires (QWRs) and quantum wells (QWs).... We present a theoretical investigation of the influence of photo-excitation and spin wave scattering on magnetization of the (Ga,Mn)As diluted magnetic semiconductor (DMS) quantum wires (QWRs) and quantum wells (QWs). Double time temperature dependent Green’s function formalism is used for the description of dispersion and spectral density of the systems. Our analysis indicates that spin wave scattering plays an influential role in magnetism of both systems while application of light is insignificant in quantum wells. In the absence of spin wave scattering and at sufficiently low temperatures, a result corresponding to the specific heat of dominating electronic contributions in metals is obtained in QWs. In QWRs, however, this magnetic property is found to vary with T1/2 and α2T1/2 so that light matter coupling has a leading effect on lower temperatures, where α is the light matter coupling factor and T is the temperature. 展开更多
关键词 Heat Capacity Magnetization PHOTO-EXCITATION QUANTUM WELLS QUANTUM Wires Spin Wave SCATTERING
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Thermally Agitated Self Assembled Carbon Nanotubes and the Scenario of Extrinsic Defects
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作者 Chernet Amente Keya Dharamvir 《World Journal of Nano Science and Engineering》 2015年第1期17-25,共9页
Employing the arc discharge method we prepared carbon nanotubes, CNTs, in open air deionized water. Their morphology was studied varying the annealing temperature and characterizing by Raman Spectroscopy, Transmission... Employing the arc discharge method we prepared carbon nanotubes, CNTs, in open air deionized water. Their morphology was studied varying the annealing temperature and characterizing by Raman Spectroscopy, Transmission Electron Microscopy (TEM), X-Ray Diffractogram (XRD) and Energy Dispersion X-Ray (EDX). According to the study, the CNTs are found self-assembled where the graphene sheets and/or defects are observed sort out themselves with enhancement of temperature. 展开更多
关键词 Arc Discharge Carbon NANOTUBES DEFECTS SELF Assembling Thermal AGITATION
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Compressive and Flexural Strength of Recycled Reactive Powder Concrete Containing Finely Dispersed Local Wastes
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作者 Demiss Belachew Asteray Walter Odhiambo Oyawa Stanley Muse Shitote 《Open Journal of Civil Engineering》 2018年第1期12-26,共15页
The main objective of this experimental study is to investigate the behavior of Recycled Reactive Powder Concrete (RRPC) developed from finely dispersed local waste raw materials. In this study, RRPC was developed by ... The main objective of this experimental study is to investigate the behavior of Recycled Reactive Powder Concrete (RRPC) developed from finely dispersed local waste raw materials. In this study, RRPC was developed by utilizing local wastes (finely dispersed waste glass powder, waste fly ash and waste ceramic powder) together with Portland cement, fine sand, admixture, steel fibers and water through full replacement of silica fume as well as quartz powder for sustainable construction practice. In this study, all raw materials for making RRPC were analyzed for X-Ray Fluorescence analysis. For sustainability of local construction works, this study employed standard curing method at ambient temperatures instead of steam curing at higher temperatures. Moreover, hand mixing was used throughout the study. To evaluate the structural performances of the developed RRPC mixes, compressive and flexural strengths of RRPC were investigated experimentally and compared with the control mix. The experimental results indicated that replacing the silica fume fully by finely dispersed local waste glass powder (GP) and fly ash (FA) is a promising approach for local structural construction applications. Accordingly, a mean compressive strength of 62.9 MPa and flexural strength of 8.8 MPa were developed using 50% GP-50% FA at 28thdays standard curing. In this study, 17.56% larger compressive strength and 30.6% flexural strength improvements were observed as compared to the control mix. 展开更多
关键词 LOCAL WASTES Recycled Reactive Powder Concrete COMPRESSIVE STRENGTH FLEXURAL STRENGTH Standard CURING
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Synthesis, Spectroscopic, Structural Characterization, Conductivity and Electrochemical Studies of a Schiff Base Ligand and Its Copper Complexes
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作者 Atinafu Abayneh Tesfay Gebretsadik +1 位作者 Sisay Tadesse Madhu Thomas 《Advances in Chemical Engineering and Science》 2018年第4期241-254,共14页
Schiff base ligand (L) derived from glyoxal and 4-aminoantipyrine was synthesized. The ligand (L) has been characterized by IR, NMR, electronic spectral studies and electrochemical studies. Cu(II) complexes of a Schif... Schiff base ligand (L) derived from glyoxal and 4-aminoantipyrine was synthesized. The ligand (L) has been characterized by IR, NMR, electronic spectral studies and electrochemical studies. Cu(II) complexes of a Schiff base ligand (L) from 4-aminoantpyrine and glyoxal having the composition [CuL1]X2 where X = Cl&macr;?or NO3&macr;? have been prepared and characterized by elemental analysis, electrical conductivity in non-aqueous solvent, infrared and electronic, as well as cyclic voltammetric studies. L acts as a neutral tetradentate ligand coordinating through both the carbonyl oxygen and azomethine nitrogen. On both the complexes both the anions are not coordinated. A square planar geometry is assigned for complexes. The electrochemical studies of ligand show a typical cyclic voltammogram for an irreversible process. While copper(II) complexes show the typical cyclic voltammograms for quasi reversible process. 展开更多
关键词 SCHIFF Base LIGAND Copper(II) COMPLEXES Cyclic VOLTAMMETRY
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Assessing the Awareness and Usage of Quality Control Tools with Emphasis to Statistical Process Control (SPC) in Ethiopian Manufacturing Industries
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作者 Leakemariam Berhe Tesfay Gidey 《Intelligent Information Management》 2016年第6期143-169,共27页
Introduction: The present work was devoted to assess the awareness and usage of quality control tools with the emphasis on statistical process control in Ethiopian manufacturing industries. Semi structured questionnai... Introduction: The present work was devoted to assess the awareness and usage of quality control tools with the emphasis on statistical process control in Ethiopian manufacturing industries. Semi structured questionnaire has been employed to executive and technical managers of manufacturing industries of various size and specialism across the country. Stratified random sample method by region was used to select sample industries for the study. The samples used for this study are industries mainly from Oromiya, Addis Ababa, Tigray, Amara, SNNP and Diredawa regions proportional to their size of the available industries. Methods: Exploratory method and descriptive statistics was used for data analysis. Available documents and reports related to quality control policy of the selected companies were investigated. Results and Discussions: The number of manufacturing industries involved in this study was 44. Of the sampled manufacturing industries about 60% are from Oromiya and Addis Ababa regions. It has been reported that 100% of the respondents said that the importance of quality control tools is very important to their organizations’ productivity and quality improvement (Figure 3). Quality control professionals were also asked the extent to which quality control system is working in their industry and majority of the respondents (45%) have indicated that quality control system is working to some extent in their respective industries (Figure 18). Conclusions and Recommendations: Most of the quality department of the industries did not fully recognize the importance of statistical process control as quality control tools. This is mainly due to lack of awareness and motivation of the top managements, shortage of man power in the area, and others together would make it difficult to apply quality control tools in their organization. In general, the industries in Ethiopia are deficient in vigor and found to be stagnant hence less exposed to a highly competitive market and don’t adopt the latest quality control techniques in order to gain knowledge about systems to improve quality and operational performance. We conclude that quality management system has to be established as an independent entity with a real power and hence the quality control department which is responsible for quality can make an irreversible decision with respect to quality of any given product. Moreover, the concerned bodies (government and ministry of industries) should give attention and work together with universities to ensure how these statistical process control techniques could be incorporated in a curriculum of the universities at higher levels in degree and masters programs. Furthermore, different trainings which could improve quality and efficiency of their respective management system should be given as short and long term to the employees including top and middle managers found in various industries relevant to their process. 展开更多
关键词 Quality Products AWARENESS USAGE Statistical Process Control Ethiopia
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Carcass Traits, Meat Yield and Primal Meat Cuts from Arsi, Harar, Ogaden and F1 Jersey*Horro Crossbred Bulls Fed Corn Silage Based Similar Finishing Diet
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作者 Chala Merera Erge Yesihak Yusuf Mummed +3 位作者 Mohammed Yusuf Kurtu Ahmedin Abdurehman Musa Mesfin Tafesse Gemeda Travis Gene O’Quinn 《Open Journal of Animal Sciences》 2022年第2期251-270,共20页
This study was conducted with the objective to determine carcass traits, meat yield, and primal meat cuts of Arsi, Harar, Jersey*Horro crossbred, and Ogaden cattle breeds at Haramaya University, Ethiopia. A total of 1... This study was conducted with the objective to determine carcass traits, meat yield, and primal meat cuts of Arsi, Harar, Jersey*Horro crossbred, and Ogaden cattle breeds at Haramaya University, Ethiopia. A total of 12 bulls of four cattle breeds (3 Arsi, 3 Harar, 3 F1 Jersey*Horro crossbred and 3 Ogaden) with almost similar ages were randomly assigned to four treatments in a completely randomised design (CRD). Data on carcass traits, meat yield, and primal meat cuts were analyzed using the General Linear Model (GLM) of the Statistical Analysis Software (SAS) 9.4 version. The overall averages of live body weight, hot carcass weight, chilled carcass weight, dressing percentages based on hot carcass weight, and rib eye area of experimental cattle breeds were 215.58 kg, 102.93 kg, 99.56 kg, 47.61%, and 8.13 inch<sup>2</sup>, respectively. The hot carcass weight and chilled carcass weight of the Ogaden (136.57;133.30 kg, resp.) breed were higher (p < 0.01) compared to other experimental cattle breeds. Dressing percentages based on hot carcass weight were higher (p < 0.05) for the Ogaden (49.61%) and Arsi (49.82%) cattle breeds compared to Harar and Jersey*Horro crossbred (45.73%, 45.27%, resp.) cattle breeds. The average meat yield and proportion of meat yield of cattle breeds were 77.52 kg and 77.46%, respectively. With a linear regression coefficient of prediction (R<sup>2</sup>) ranging from 52.26% to 93.58%, primal meat cuts significantly (p dicted meat yield. In conclusion, the breed of cattle had a significant (p 0.05) influence on live body weight, hot and chilled carcass weight, dressing percentage, rib eye area, subcutaneous fat thickness, meat yield, and the weights of most primal meat cuts. The Ogaden cattle breed had a higher and better meat yield, carcass traits, and most primal meat cuts compared to other experimental cattle breeds. Furthermore, the inclusion of corn silage in the diet of fattening bulls improved the carcass and meat yield. Therefore, the performance of Ogaden cattle compared to other and previous studies suggests the possibility of using this breed for export purposes in addition to Borana and Harar cattle breeds in the future. 展开更多
关键词 Meat Yield Carcass Traits Primal Meat Cuts Cattle Breeds Corn Silage
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Distribution of total mercury in surface sediments and African catfish(Clarias gariepinus)from Akaki River catchment and Aba Samuel Reservoir,downstream to the mega-city Addis Ababa,Ethiopia
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作者 Alemnew Berhanu Kassegne Jonathan O.Okonkwo +3 位作者 Tarekegn Berhanu Esho Kebede Nigussie Mekonnen Tshia Malehase Seyoum Leta Asfaw 《Emerging Contaminants》 2018年第1期32-39,共8页
Total mercury(THg)levels were determined in sediment(n=22)and muscle of Clarias gariepinus(n=36)in dry and rainy seasons from Akaki River catchment and Aba Samuel Reservoir,Ethiopia in 2016-2017.The analyses of THg we... Total mercury(THg)levels were determined in sediment(n=22)and muscle of Clarias gariepinus(n=36)in dry and rainy seasons from Akaki River catchment and Aba Samuel Reservoir,Ethiopia in 2016-2017.The analyses of THg were performed using cold vapor-atomic absorption spectrometer(CV-AAS)after acid digestion technique.The relationship of THg levels to size of the fish has also been investigated.The THg levels in sediments range from 9.5e43.8 mg/kg dry wt in the dry and 20.6e175.4 mg/kg dry wt in the rainy seasons.This study indicated that the levels of THg in sediments varies spatially and seasonally.In both seasons,THg levels increased from upstream to downstream areas,revealing increased anthropogenic inputs of mercury pollution.It was also found that the THg concentrations in all the sediment samples were below the US EPA guideline value of 200 mg/kg dry wt.The THg levels in Clarias gariepinus were in the range from 360e924 mg/kg dry wt in the dry and 325e1233 mg/kg dry wt in the rainy seasons,and had positive relationship to the total length and body weight.The THg concentrations found in Clarias gariepinus were within the acceptable guidelines of the FAO/WHO.Therefore,the muscle of Clarias gariepinus from the study area is not hazardous to human health with respect to mercury.However,the average value of THg seems to be slightly higher than results reported from other Ethiopian freshwater bodies.Thus,monitoring of mercury species in sediment and different organs of fish are strongly recommended. 展开更多
关键词 pollution. MERCURY UPSTREAM
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Molecular phylogeny of the genus Corchorus(Grewioideae,Malvaceae s.l.) based on nuclear rDNA ITS sequences
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作者 Solomon Benor 《The Crop Journal》 SCIE CAS CSCD 2018年第5期552-563,共12页
A molecular phylogenetic analysis of the genus Corchorus(Grewioideae,Malvaceae s.l.)is presented,based on sequences of the nuclear ribosomal DNA internal transcribed spacer(ITS)region for 144 accessions representing 4... A molecular phylogenetic analysis of the genus Corchorus(Grewioideae,Malvaceae s.l.)is presented,based on sequences of the nuclear ribosomal DNA internal transcribed spacer(ITS)region for 144 accessions representing 47 species.Several other genera from the subfamily Grewioideae,namely Pseudocorchorus,Triumfetta,Sparrmannia,Entelea,and Grewia,were included as outgroups.The monophyly of the genus was well supported by all phylogenetic analyses(maximum likelihood,Bayesian approaches,and parsimony),and Corchorus was divided into four major clades.The majority of African species formed a statistically highly supported and distinct clade separated from the other pantropically distributed species.Several endemic species from Australia,New Caledonia,and tropical America were nested within this distinct clade,indicating dispersal from Africa to the rest of the pantropics.Based on the taxa included in this study,the two cultivated species(C.olitorius and C.capsularis)shared a common ancestry with wild species of C.africanus,C.brevicornatus,C.pseudocapsularis,C.pseudo-olitorius,C.urticifolius,C.pilosus,C.orinocensis,and C.cunninghamii.Pseudocorchorus,previously considered an accepted genus,was nested within the genus Corchorus and shared a common ancestry especially with C.depressus and C.siliquosus.Based on morphological and anatomical similarity as well as the results of the present molecular findings,inclusion of the six Pseudocorchorus species into Corchorus is proposed,with Pseudocorchorus as a synonym of Corchorus.Of the included outgroup taxa,Triumfetta is the closest sister to Corchorus,while the common ancestor of Corchorus/Pseudocorchorus,Triumfetta,Sparrmannia,and Entelea is Grewia.A further phylogenetic study with more taxa mainly from Australia,together with additional molecular markers and morphological investigation,would help to test the hypothesis on the biogeography and growth form evolution of the genus Corchorus. 展开更多
关键词 Corchorus JUTE Malvaceae s.l. PHYLOGENY Pseudocorchorus
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Characteristics of bacterial sepsis among patients with visceral leishmaniasis
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作者 Mengistu Endris Yegnasew Takele +4 位作者 Desalegn Woldeyohannes Chandrashekhar Unakal Feleke Moges Moges Tiruneh Ermias Diro 《Asian Pacific Journal of Tropical Biomedicine》 SCIE CAS 2014年第11期871-875,共5页
Sepsis is one of the major causes and predictors of death in patients with visceral leishmaniasis(VL).Globally,incidence rate of sepsis ranged from 56-91 cases per 100000 people,with a mortality rate of 30%.Incidence ... Sepsis is one of the major causes and predictors of death in patients with visceral leishmaniasis(VL).Globally,incidence rate of sepsis ranged from 56-91 cases per 100000 people,with a mortality rate of 30%.Incidence of sepsis has been raised due to aging of the population and the higher incidence of immunosuppressive conditions such as HIV.VL and others.The prevalence of sepsis was reported from 4.2%to 32.3%and 14.1%in VL and VL-HIV coinfectcd patients,respectively.The mortality rate of VL patients with sepsis is greater than50%.Factors associated with sepsis in VL patients are immune suppression,pancytopenia.HIV co-infection,age <l year old and >40 years old,indwelling of central venous lines and hospitalization.Although antimicrobial susceptibility patterns were not well reported,both Gram-positive and Gram-negative bacteria were isolated from patients with VL.So far.limited information is available on sepsis in VL.especially in VL-HIV coinfected patients.Therefore,further studies about sepsis prevalence,causative agents and their antibiotic patterns,and associated factors among VL and VL-HIV coinfectcd patients arc necessary.This review provides information about bacterial sepsis in patients with VL. 展开更多
关键词 SEPSIS VISCERAL LEISHMANIASIS VL-HIV HIV/AIDS
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Comparing Data Mining Techniques in HIV Testing Prediction
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作者 Tesfay Gidey Hailu 《Intelligent Information Management》 2015年第3期153-180,共28页
Introduction: The present work compared the prediction power of the different data mining techniques used to develop the HIV testing prediction model. Four popular data mining algorithms (Decision tree, Naive Bayes, N... Introduction: The present work compared the prediction power of the different data mining techniques used to develop the HIV testing prediction model. Four popular data mining algorithms (Decision tree, Naive Bayes, Neural network, logistic regression) were used to build the model that predicts whether an individual was being tested for HIV among adults in Ethiopia using EDHS 2011. The final experimentation results indicated that the decision tree (random tree algorithm) performed the best with accuracy of 96%, the decision tree induction method (J48) came out to be the second best with a classification accuracy of 79%, followed by neural network (78%). Logistic regression has also achieved the least classification accuracy of 74%. Objectives: The objective of this study is to compare the prediction power of the different data mining techniques used to develop the HIV testing prediction model. Methods: Cross-Industry Standard Process for Data Mining (CRISP-DM) was used to predict the model for HIV testing and explore association rules between HIV testing and the selected attributes. Data preprocessing was performed and missing values for the categorical variable were replaced by the modal value of the variable. Different data mining techniques were used to build the predictive model. Results: The target dataset contained 30,625 study participants. Out of which 16,515 (54%) participants were women while the rest 14,110 (46%) were men. The age of the participants in the dataset ranged from 15 to 59 years old with modal age of 15 - 19 years old. Among the study participants, 17,719 (58%) have never been tested for HIV while the rest 12,906 (42%) had been tested. Residence, educational level, wealth index, HIV related stigma, knowledge related to HIV, region, age group, risky sexual behaviour attributes, knowledge about where to test for HIV and knowledge on family planning through mass media were found to be predictors for HIV testing. Conclusion and Recommendation: The results obtained from this research reveal that data mining is crucial in extracting relevant information for the effective utilization of HIV testing services which has clinical, community and public health importance at all levels. It is vital to apply different data mining techniques for the same settings and compare the model performances (based on accuracy, sensitivity, and specificity) with each other. Furthermore, this study would also invite interested researchers to explore more on the application of data mining techniques in healthcare industry or else in related and similar settings for the future. 展开更多
关键词 Data MINING Comparison PREDICTIVE MODELING HIV TESTING Ethiopia
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