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Open Journal of Animal Sciences 2021年第2期11卷 125-138页

作者： Beshir Hussien yonas hailu Mitiku Eshetu Oromia Agricultural Research Institute Yabello Pastoral and Dryland Agriculture Research Center Yabello Ethiopia School of Animal and Range Sciences Haramaya University Dire Dawa Ethiopia

The study was conducted to investigate the physicochemical properties and microbial quality of ititu produced in the Borana zone. A total number of 35 ititu samples, 30 traditionally made plus 5 laboratories made ititu, were analyzed for their physicochemical properties and microbiological quality. The overall average (±SD) values for pH, titratable acidity, total protein, fat, total solids, and ash were 3.59% ± 0.04%, 2.86% ± 0.18%, 7.26% ± 0.41%, 9.85%

关键词： ititu Cow Fermented Milk Microbiology Physicochemistry

Preservation of Raw Camel Milk by Lactoperoxidase System Using Hydrogen Peroxide Producing Lactic Acid Bacteria

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Open Journal of Animal Sciences 2020年第3期10卷 387-401页

作者： Dakalo Dashe Egon Bech Hansen Mohammed Yusuf Kurtu Tesfemariam Berhe Mitiku Eshetu yonas hailu Amsalu Waktola Adane Shegaw School of Animal and Range Sciences Haramaya University Dire Dawa Ethiopia Division for Diet Disease Prevention and Toxicology National Food Institute Technical University of Denmark Kgs. Lyngby Den-mark

This study was conducted to investigate the effect of lactic acid bacteria (LAB) activated lactoperoxidase system (LPs) on keeping quality of raw camel milk at room temperature. Camel milk samples were collected from Errer valley, Babile district of eastern Ethiopia. The level of hydrogen peroxide (H2O2) for activation of LPs was optimized using different levels of exogenous H2O2. Strains of LAB (Lactococcus lactis 22333, Weissella confusa 22308, W. confusa 22282, W. confusa 22296, S. Infatarius 22279 and S. lutetiensis 22319) with H2O2 producing properties were evaluated, and W. confusa 22282 was selected as the best strain to produce H2O2. Storage stability of the milk samples was evaluated through the acidification curves, titratable acidity (TA), total bacterial count (TBC) and coliform counts (CC) at storage times of 0, 6, 12, 18, 24 and 48 hours. The LP activity and the inhibitory effect of activated LPs were evaluated by growing E. coli in pasteurized and boiled camel milk samples as contaminating agent. Results indicated that the W. confusa 22282 activated LPs generally showed significantly (P < 0.05) slower rates of acidification, lactic acid production and lower TB

关键词： Camel Milk Lactoperoxidase System Lactic Acid Bacteria Preservation

Multidirectional 3D printed functionally graded modular joint actuated by TCPFL muscles for soft robots

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Bio-Design and Manufacturing 2019年第4期2卷 256-268页

作者： Armita Hamidi Yara Almubarak yonas Tadesse Humanoid Bio-robotics and Smart Systems(HBS)LaboratoryMechanical Engineering DepartmentThe University of Texas at DallasRichardsonTX 75080USA

Highly deformable bodies are essential for numerous types of applications in all sorts of environments. Joint-like structures comprising a ball and socket joint have many degrees of freedom that allow mobility of many biomimetic structures. Recently, soft robots are favored over rigid structures for their highly compliant material, high-deformation properties at low forces, and ability to operate in di fficult environments. However, it is still challenging to fabricate complex designs that satisfy application constraints due to the combined e ffects of material properties, actuation method, and structural geometry on the performance of the soft robot. Therefore, a combination of a rigid joint and a soft body can help achieve modular robots with fully functional body morphology. Yet, the fabrication of soft parts requires extensive molding for complex shapes, which comprises several processes and can be time-consuming. In addition, molded connections between extremely soft materials and hard materials can be critical failing points. In this paper, we present a functionally graded 3D-printed joint-like structure actuated by novel contractile actuators. Functionally graded materials (FGMs) via 3D printing allow for extensive material property enhancement and control which warrant tunable functionalities of the system. The 3D-printed structure is made of 3 rigid ball and socket joints connected in series and actuated by integrating twisted and coiled polymer fishing line ( TCPFL) actuators, which are con fined in the FGM accordion-shaped channels. The implementation of the untethered T CPFL actuation system can be highly bene ficial for deployment in environments that require low vibrations and silent actuation. The fishing line TCP actuators produce an actuation strain up to 40% and bend the joint up to 40° in any direction. The T CPFL can be actuated individually or as a group to control the bending trajectory of the modular joint, which is bene ficial when deployed i

关键词： Functionally graded 3D-printed Joint Multidirectional Fishing line TCP

HM-EH-RT:hybrid multimodal energy harvesting from rotational and translational motions

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International Journal of Smart and Nano Materials 2013年第4期4卷 257-285页

作者： Miles Larkin yonas Tadesse Department of Mechanical Engineering Erik Jonsson School of Engineering and Computer ScienceThe University of Texas at DallasRichardsonTX 75080USA

This paper presents a novel hybrid multimodal energy harvesting device consisting of an unbalanced rotary disk that supports two transduction methods,piezoelectric and *** device generates electrical energy from oscillatory motion either orthogonal or parallel to the rotary axis to power electronic *** models for the electromagnetic and piezoelectric systems were developed to describe the mechanical and electrical behavior of the *** these models,numerical simulations were performed to predict power generation *** device was fabricated,and several components were optimized *** energy harvester was then experimentally characterized using a modal shaker in several different *** device generates a maximum RMS power output of 120 mW from the electromagnetic system at 5 Hz and 0.8 g,and 4.23 mW from the piezoelectric system at 20.2 Hz and 0.4 g excitation *** device is 180 mm in diameter and 45 mm thick including the rotor *** size optimization will produce an energy harvester capable of being used as a wearable device to power mobile electronics for multiple applications.

关键词： energy harvesting piezoelectric electromagnetic wearable device multimodal

Influence of temperature on preparing mesoporous mixed phase N/TiO2 nanocomposite with enhanced solar light photocatalytic activity

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Frontiers of Materials Science 2019年第4期13卷 352-366页

作者： Elias ASSAYEHEGN Ananthakumar SOLAIAPPAN yonas CHEBUDIE Esayas ALEMAYEHU Materials Science and Technology Division National Institute for Interdisciplinary Science and Technology(CSIR-NIIST)Thiruvananthapuram-695019India National Centre for Catalysis Research and Department of ChemistryIndian Institute of Technology(IIT)-MadrasChennai-600036India Faculty of Materials Science and Engineering Jimma UniversityP.O.Box 378JimmaEthiopia Department of Chemistry Addis Ababa UniversityP.O.Box 1176Addis AbabaEthiopia Faculty of Civil and Environmental Engineering Jimma UniversityJimmaP.O.Box 378Ethiopia

Nitrogen-doped titanium dioxide(N/TiO2)nanophotocatalysts were successfully synthesized in the presence of environmentally benign nitrogen dopant source,guanidinium chloride,by the sol-gel *** effect of calcination temperature(300–600℃)on their physicochemical properties was investigated by means XRD,XPS,FESEM,HRTEM,Raman spectroscopy,UV-vis DRS,PL and ***,their photocatalytic activities were evaluated against rhodamine B(RhB)degradation under direct sun *** showed that the crystal phase of spheroidal N/TiO2 nanoparticles was changed from anatase(300℃)to rutile(600℃)via an intermediate anatase/rutile(A/R)mixed phase(400–500℃),and the RhB photodegradation performance was increased with the decrease of the calcination ***,N/TiO2 prepared at 400℃demonstrated the best degradation performance(99%)after 5 h *** enhanced performance with high photostability was mainly attributed to its higher surface area and pore volume,stronger light absorption,and lower recombination *** nanomaterials have practical applications for environmental remediation.

关键词： nitrogen doping TiO2 rhodamine B mixed photocatalyst guanidinium chloride

A Case Study on Embankment Stability of High-speed Railway Cold Regions

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A Case Study on Embankment Stability of High-speed Railway C...

作者： GEBRESELASSIE yonas GEBREMESKEL 绍兴文理学院

学位级别：硕士

填料层的季节性冻胀和融沉是导致季节性冻土区路基发生变形破坏的主要因素之一。随着工程技术和监测手段的不断提高,普通路基工程的防冻胀和融沉问题已经得到了较好的解决。然而,季节性冻土区高速铁路路基对变形要求极为苛刻,给路基变... 详细信息

填料层的季节性冻胀和融沉是导致季节性冻土区路基发生变形破坏的主要因素之一。随着工程技术和监测手段的不断提高,普通路基工程的防冻胀和融沉问题已经得到了较好的解决。然而,季节性冻土区高速铁路路基对变形要求极为苛刻,给路基变形的控制及防治带了巨大挑战。本文基于兰新高铁K1962+168路基监测段2015-2016年的温度、水分和变形监测数据,分析了诱发路基变形的主要控制因素。研究结果表明,在夏秋交替季节,路基温度变化幅度最大,约为4～6 C,最大约为6.5 C,最小约为2 C.12月份至2月份,路基填料层的水分迁移速度较快,约为12%～16%。路基的最大冻胀量约为20 mm。不同填料层的路基冻胀变形表现出非均质性,在路基表层0.5～1.5 m处,路基产生的冻胀量最大,约为11.3 mm。路基填料层的冻结深度和冻结时间呈现出指数增长关系,最大冻结深度约为2.5 m。研究结果可以为高速铁路路基冻胀防治提供一定的理论和实践依据,可以为寒区高速铁路路基工程设计提供有效参考。

关键词：高速铁路路基的温度分布土壤水分冻胀变形量

Anti-schistosomal activities of Echinops kebericho Mesfin root and Hagenia abyssinica (Bruce) J.F Gmel flower part crude extracts in Swiss albino mice

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Asian Pacific Journal of Tropical Medicine 2018年第10期11卷 570-575页

作者： yonas Alemu Zeleke Mekonnen Ahmed Zeynudin Moti Yohannes Abdissa Biruksew Sultan Suleman School of Medical Laboratory Sciences Jimma University School of Veterinary Medicine Jimma University School of Pharmacy Jimma University

Objective: To evaluate the in vivo antischistosomal activities of the crude extracts of Echinops kebericho Mesfin(E. kebericho) root and Hagenia abyssinica(Bruce) J.F. Gmel(H. abyssinica) flower. Methods: Mice were infected with(150 ± 10) Schistosoma mansoni cercariae by paddling technique. Crude extracts were administered orally for five consecutive days at doses of 300, 600 and 1 200 mg/kg/day along with 200 mg/kg/day praziquantel and 3% tween 80 given as a control. Results: E. kebericho root extract showed a statistically significant(P < 0.05) reduction in fecal egg count of 64.44%, 42.96% & 26.82% and worm burden of 65.71%, 47.86% & 31.43% at treatment doses of 1 200 mg/kg/day, 600 mg/kg/day and 300 mg/kg/day, respectively. Similarly, H. abyssinica flower extracts showed a significant(P < 0.05) reduction in fecal egg count up to 84.57%, 77.06% & 63.89% and worm burden of 91.43%, 81.43% & 70.71% at a respective dose levels. In addition, a significant(P < 0.05) reduction in liver granuloma score was observed in all H. abyssinica administered dose groups and E. kebericho at 1 200 mg/kg/day dose group as compared to infected untreated control group. Conclusions: H. abyssinica and E. kebericho crude extracts show a promising antischistosomal activity.

关键词： Schistosoma mansoni Echinops kebericho Hagenia abyssinica Crude extract Antischistosomal activity Ethiopia

Production Performance of Chicken under Farmers’ Management and Their Roles at Urban Household Economy in Southern Ethiopia

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Agricultural Sciences 2020年第2期11卷 178-190页

作者： yonas Kejela Department of Animal Science College of Agriculture and Natural Resource Jinka University Jinka Ethiopia

This study was conducted to assess production performance of chicken under farmers’ management and their roles in the household economy of local and exotic chickens reared at Yirgalem and Hawassa towns of Southern Ethiopia. Purposive sampling method was used for selecting the respondents. Totally, 180 respondents were selected based on their experience in chicken production. The study indicates that the average number of eggs set for incubation was 10.05 ±0.81 of which the hatchability was 8.42 ±1.19 eggs. The age at first egg laying for the native chickens raised at Hawassa and Yirgalem towns was 6.31 ±0.53 and 6.10 ±0.30 months respectively with differences recorded both within and between the locations. The age at first egg laying of the Sasso hens was 5.24 ±0.43 months while the age at first egg lay for Bovans was 5.37 ±0.49 months. The difference was observed (P <0.05) across the studied locations. The values were lower when compared to those of the native chickens. It was also observed that the contributions of the exotic chickens to the livelihood and food security of the rearers were insignificant. It was concluded from this study that the exotic chickens in the study areas performed fairly well and could do so further if they are provided with better health care, scientific nutrition and management.

关键词： Exotic and Local Chickens Households’ Economy Performance Southern Ethiopia

Ecological role of the giant root-rat(Tachyoryctes macrocephalus)in the Afroalpine ecosystem

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Integrative Zoology 2017年第4期12卷 333-344页

作者： JanŠKLÍBA Tereza VLASATÁ Matěj LÖVY Ema HROUZKOVÁ yonas MEHERETU Claudio SILLERO-ZUBIRI RadimŠUMBERA Faculty of Science University of South BohemiaCzech Republic Institute of Entomology Biology Centre CASCzech Republic Department of Biology College of Natural and Cmputational SciencesMekelle UniversityEthiopia Wildlife Conservation Research Unit Zoology DepartmentUniversity of OxfordUK

Rodents with prevailing subterranean activity usually play an important role in the ecosystems of which they are a part due to the combined effect of herbivory and soil *** is the case for the giant root-rat Tachyoryctes macrocephalus endemic to the Afroalpine ecosystem of the Bale Mountains,*** studied the impact of root-rats on various ecosystem features within a 3.5-ha study locality dominated by Alchemilla pasture,which represents an optimal habitat for this species,in 2 periods of a *** root-rats altered plant species composition,reducing the dominant forb,Alchemilla abyssinica,while enhancing Salvia merjame and a few other species,and reduced vegetation cover,but not the fresh plant *** burrows were abandoned by root-rats,other rodents took them over and *** increased ***-rat burrowing created small-scale heterogeneity in soil compactness due to the backfilling of some unused burrow *** compacted soil tended to be rich in nutrients,including carbon,nitrogen and phosphorus,which likely affected the plant growth on sites where the vegetation has been reduced as a result of root-rat foraging and burrowing.

关键词： Afroalpine ecosystem engineer fossorial rodent soil disturbance Tachyoryctes macrocephalus

Preliminary investigation on rodent–ectoparasite associations in the highlands of Tigray, Northern Ethiopia:implications for potential zoonoses

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Integrative Zoology 2011年第4期6卷 366-374页

作者： Meheretu yonas Kiros WELEGERIMA Anne LAUDISOIT Hans BAUER Kindeya GEBREHIWOT Seppe DECKERS Abdul KATAKWEBA Rhodes MAKUNDI Herwig LEIRS Department of Biology Mekelle UniversityMekelleEthiopia Evolutionary Ecology Group University of AntwerpBelgium Institute of Integrative Biology University of LiverpoolBiosciencesLiverpoolUK Institutional University Cooperation Project Mekelle UniversityMekelleEthiopia Department of Land Resources Management and Environmental Protection Mekelle UniversityMekelleEthiopia Division of Soil and Water Management K.U.LeuvenHeverleeBelgium Pest Management Center Sokoine University of AgricultureMorogoroTanzania Department of Integrated Pest Management University of AarhusSlagelseDenmark

We studied associations between rodents and their arthropod ectoparasites in crop fields and household compounds in the highlands of Tigray,Northern *** infestation indices,such as percent infestation,mean abundance,prevalence and host preferences,were calculated for each *** total,172 rodents from crop fields and 97 from household compounds were *** species and numbers trapped from the crop fields and household compounds were Mastomys awashensis(Lavrenchenko,Likhnova&Baskevich,1998)(88 and 44),Arvicanthis dembeensis(Ruppel,1842)(63 and 37)and Acomys sp.(21 and 16),respectively.A total of 558 insects and acarids(belonging to 11 taxa)were recovered from the rodents trapped in the crop fields,and 296 insects and acarid(belonging to 6 taxa)from the rodents trapped in the household *** 66%of the rodents trapped from the crop fields and 47%of those trapped from the household compounds were infested with *** sp.(64.9%)and Xenopsylla sp.(20.6%)comprised the highest proportion of the ectoparasites recovered in the crop fields,and the same ectoparasites,but in reverse order,comprised the highest proportions in the household compounds(Xenopsylla[50.3%]and Laelaps sp.[29%]).Our study revealed that crop fields and household compounds in the highlands share similar rodents and several ***,at least 1 of the rodent species and some of the ectoparasites identified in this study were reported to have posed medical and veterinary threats in other parts of Ethiopia and neighboring countries.

关键词： ectoparasites Northern Ethiopia rodents zoonoses