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Comparative Study of Exhaust Emissions from Diesel and Syngas Powered 3.5 kW Compression Ignition Engine with and without Load

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Journal of Power and Energy Engineering 2024年第8期12卷 30-46页

作者： benson kariuki Paul Njogu Joseph Kamau Robert Kinyua Sameer Bachani Institute of Energy and Environmental Technology Jomo Kenyatta University of Agriculture & Technology Nairobi Kenya Department of Mechanical and Automotive Engineering Technical University of Mombasa Mombasa Kenya

Despite diesel engines being highly efficient, with low fuel consumption and reduced carbon dioxide emissions, they emit relatively high levels of particulate matter and oxides of nitrogen (NOx) due to high exhaust gas temperatures. Engine emissions show the quality and completeness of combustion. This paper aims to present the results of a study comparing exhaust emissions from a diesel and syngas powered engine. Syngas was produced from co-firing coal and biomass in a gasifier then cleaned, cooled and applied as an alternative fuel in an engine operated from 0 - 100% load. Exhaust-emissions were monitored at this load conditions. The exhaust-temperature was measured using thermocouples and the emission gases were analyzed using Testo 350. The emissions were lower and decreased as the engine load increased, except for sulphur dioxide and NOx. The study shows that levels of carbon monoxide, were higher in a range of 46.5 - 80.2%, while carbon dioxide was 3.3 - 18% higher compared to those from diesel. Hydrocarbon emissions were 480 and 1250 ppm for diesel and syngas respectively. The study reveals that the engine operates optimally at higher loads since hydrocarbons and oxides of carbon are low due to complete combustion at higher temperatures. Exhaust gas temperature was higher in the syngas fuel and increased as the engine load increased in the range of 455.83 - 480.03˚C which influenced the formation of NOx. NOx from diesel was found to be higher, ranging from 32.5 - 40.5%, compared to those from syngas with an engine load of 75%. The study observed that relative to diesel, the emissions of sulfur dioxide at 50% engine load were lower in a range of 23.7 - 57.1%. Emissions of hydrocarbons depended on the degree of substitution of diesel and engine load. The study therefore shows that, relative to diesel, emissions decreased when syngas was used with upgraded syngas from Prosporis juliflora presenting as the best alternative followed by Hyphanae compressa, and last

关键词： Emissions Engine Load Temperature Neat-Diesel Syngas

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Bacteriome in Ticks Collected from Domestic Livestock in Kenya

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Advances in Microbiology 2022年第2期12卷 67-82页

作者： Beth Mutai kariuki Njaanake Kimita Gathii benson B. Estambale John N. Waitumbi US Army Medical Research Directorate—Africa/Kenya Medical Research Institute Kisumu Kenya Department of Medical Microbiology University of Nairobi Nairobi Kenya Jaramogi Oginga Odinga University of Science and Technology Bondo Kenya

Background: Metagenomics approaches are increasingly being utilized as “dipstick” for microbial carriage. In this study, 16S rRNA metagenomics was used to probe for microbial community that resides in the ticks, those they pick from the environment, wildlife and livestock and to identify potential tick borne zoonoses. Methods: Tick DNA from 463 tick pools collected from domestic animals between 2007 and 2008 were amplified with primers that target the 16S rRNA V3-V4 domain and then sequenced on Illumina Miseq platform using 300 cycles version 3 kits. Ticks were pooled according to species and animal from which they were collected. A non-target control was used to track laboratory contaminants. Sequence data were analyzed using Mothur v1.3 pipeline and R v3.3.1 software and taxonomy determined using SILVA rRNA database. Shannon diversity index was used to compute bacterial diversity in each tick species before computing the means. Results: A total of 645 bacteria genera grouped into 27 phyla were identified. Four phyla contributed 97.4% of the 36,973,934 total sequences. Proteobacteria contributed 61.2% of these sequences that tarried to 33.8% genera, compared to 15.9% (23.4% genera) for Firmicutes, 15.6% (20% genera) for Actinobacteria and 4.7% (11.6% genera) for Bacteroidetes. The remaining 23 phyla only contributed 2.6% of the sequence reads (11.2% genera). Amongst the 645 genera, three groups were discernible, with the biggest group comprised commensals/symbionts that contributed 93.6% of the genera, but their individual sequence contribution was very low. Group two comprised genera that are known to contain pathogenic species, with Coxiella contributing 15,445,204 (41.8%) sequences, Corynebacterium (13.6%), Acinetobacter (4.3%), Staphylococcus (3.9%), Bacillus (2.7%) and Porphyromonas (1.6%), Ralstonia (1.5%), Streptococcus (1.3%), Moraxella (1.3%), amongst others. Group three comprised genera known to contain tick borne zoonotic pathogens (TBZ): Rickettsiae, An

关键词： Livestock Ticks Bacteriome Tick-Borne Zoonoses 16S rRNA Next Generation Sequencing

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Geometrically constrained isogeometric parameterizedlevel-set based topology optimization via trimmed elements

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Frontiers of Mechanical Engineering 2016年第4期11卷 328-343页

作者： Yingjun WANG David J. benson School of Mechanical and Automotive Engineering South China University of Technology Guangzhou 510641 China Department ofMechanical Engineering McGill University Montreal H3AOC3 Canada Department of Structural Engineering University of California SanDiego 92093 USA

In this paper, an approach based on the fast point-in-polygon (PIP) algorithm and trimmed elements is proposed for isogeometric topology optimization (TO) with arbitrary geometric constraints. The isogeometric parameterized level-set-based TO method, which directly uses the non-uniform rational basis splines (NURBS) for both level set function (LSF) parameterization and objective function calculation, provides higher accuracy and efficiency than previous methods. The integration of trimmed elements is completed by the efficient quadrature rule that can design the quadrature points and weights for arbitrary geometric shape. Numerical examples demonstrate the efficiency and flexibility of the method.

关键词： isogeometric analysis topology optimization level set method arbitrary geometric constraint trimmed element

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A Duo 4-Plex Real Time PCR for Detection of Eight Tick-Borne Zoonoses in Kenya

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Open Journal of Clinical Diagnostics 2019年第1期9卷 1-15页

作者： Beth Mutai kariuki Njaanake Kimita Gathii benson B. Estambale John N. Waitumbi US Army Medical Research Directorate-Kenya Kenya Medical Research Institute Kisumu Kenya Department of Medical Microbiology University of Nairobi Nairobi Kenya Jaramogi Oginga Odinga University of Science and Technology Kisumu Kenya

Ticks harbor multiple pathogens, most of which can be transmitted to humans. The ensuing zoonoses display non-specific symptoms that make definitive diagnosis difficult. We report here the development and evaluation of multiplex real time polymerase chain reaction (qPCR) assays for eight tick-borne zoonoses (TBZ). The assays were organized in duo formats of 4-plex each. Format 1 was optimized for Anaplasma phagocytophilum, Coxiella burnetii, Borrelia burgdoferi and Ehrlichia chaffeensis. Format 2 was optimized for Rickettsia species (spp.), Bartonella spp., Borrelia spp. other than B. burgdoferi and Babesia spp. Synthetic plasmids were used to show that the assays can specifically detect all target sequences in the same reaction tube. Assays were assayed eight times to determine assay performance and the limit of detection was determined as the lowest plasmid concentration that was amplified for all the targets. Standard curves of threshold cycle (Ct) versus copy numbers were generated and used to determine linearity and efficiency of the assays. Pairwise comparison of singleplex and multiplex assays was done using Bland-Altman plots. Prevalence was calculated as overall percentage of positive patients to each TBZ tested Assay 1 had a limit of detection of 2 copy numbers for all targets. Assay 2 was less sensitive and on average had a limit of detection of 18 gene copies. In replicate tests, both assays had intra-assay variation of less than two cycles. Multiplex assays performance was comparable to respective singleplex assays. Evaluation of 512 clinical samples collected between 2008 and 2016 from acute febrile illness patients attending hospitals in different counties in Kenya revealed a 20% prevalence of tick-borne pathogens comprising B. burgdorferi (6%), non B. burgdorferi Borrelia spp. (3%), C. burnetii (5%), A. phagocytophilum (5%), Rickettsia spp. (2%), E. chaffeensis (0.8%), Bartonella spp. (0.8%), and Babesia spp. (0.4%). The high analytical sensitivity s

关键词： Tick-Borne-Zoonoses Multiplex Real Time PCR Acute Febrile Illness

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Evaluation of Three Rapid Diagnostic Test Kits in the Diagnosis of <i>Plasmodium</i>Species Infections among Primary School Children in Baringo County, Kenya

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Open Journal of Clinical Diagnostics 2017年第1期7卷 31-44页

作者： Collince Jared Omondi Lucy Muthony Kamau Humphrey kariuki Njaanake Douglas Anyona Daniel Onguru benson Estambale Department of Zoological Sciences Kenyatta University Nairobi Kenya Department of Medical Microbiology College of Health Sciences University of Nairobi Nairobi Kenya School of Health Sciences Jaramogi Oginga Odinga University of Science and Technology Bondo Kenya

Background: Due to the difficulty in implementing microscopy-based definitive diagnosis of malaria especially in resource-poor areas, rapid diagnostic test (RDT) kits as alternatives have been developed by different companies. Kits from different companies may differ in sensitivity and specificity. It is therefore imperative to conduct field evaluation of kits from different manufacturers before they are recommended for widespread use in diagnosis of malaria. The present study sought to evaluate the performance of malaria RDT kits from two manufacturers against microscopy in detection of Plasmodium spp. infections among primary school children in Baringo County, Kenya. Methods: Two cross-sectional comparative surveys to assess three RDT kits (CareStart HRP-2, SD Bioline Ag-Pf and SD Bioline Ag-Pf/Pan) were conducted on 561 pupils from three primary schools within the Kerio Valley of Baringo County, Kenya. Results: A total of 561 blood samples were tested for Plasmodium spp. within a period of four months. SD Bioline Ag-Pf/ Pan RDT kit had a higher sensitivity (90%) compared to that of CareStart HRP-2 (70%) but this was not statistically significant (McNemar’s χ2 = 0.5, df = 1, p = 0.4795). The sensitivity of SD Bioline Ag-Pf was the same as that of Care Start HRP-2 (82.4%). The number of positive samples by microscopy was relatively lower than those detected by RDT kits. Two cases of non-P. falciparum infections were detected by RDT kits during the second survey. Conclusion: The results of the present study suggest that the performance of the three kits in the diagnosis of P. falciparum infections was better than microscopy. The sensitivity of SD Bioline Ag-Pf/Pan was slightly greater than that of Care Start HRP-2, although not statistically different.

关键词： Rapid Diagnostic Tests Microscopy Malaria Sensitivity Specificity Baringo

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Why nanodiamond carriers manage to overcome drug resistance in cancer

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Cancer Drug Resistance 2020年第4期3卷 854-866页

作者： Veronika benson Abbas Amini Institute of Microbiology Czech Academy of SciencesPrague 14220Czech Republic Department of Mechanical Engineering Australian College of KuwaitSafat 13015Kuwait Center for Infrastructure Engineering Western Sydney UniversityPenrithNSW 2751Australia

Nanodiamonds represent an attractive potential carrier for anticancer *** main advantages of nanodiamond particles with respect to medical applications are their high compatibility with non-cancerous cells,feasible surface decoration with therapeutic and cancer-cell targeting molecules,and their relatively low manufacturing ***,nanodiamond carriers significantly increase treatment efficacy of the loaded drug,so anticancer drugs execute more effectively at a lower ***,lower drug dose results in less extensive side *** carriers decorated with a targeting molecule accumulate primarily in the tumor tissue,and those nanodiamond particles impair efflux of the drug from cancer *** approaches considering nanodiamond carriers were already tested in vitro,as well as in ***,researchers focus particularly on the possible side effects of nanodiamond carriers applied systemically in *** behavior of nanodiamond carriers depends heavily on their surface coatings,so each therapeutic complex must be evaluated ***,it seems that site-specific application of nanodiamond carriers is a rather safe therapeutic approach,but intravenous application needs further *** benefits of nanodiamond carriers are remarkable and represent a potent approach to overcome the drug resistance of many cancers.

关键词： Nanodiamond drug carrier drug resistance cancer therapy nanoparticles

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Neurogenic hypothesis and psychiatric disorders

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Chinese Science Bulletin 2013年第26期58卷 3188-3198页

作者： LAU benson WuiMan LEE Jada ChiaDi SO KwokFai Department of Rehabilitation Science The Hong Kong Polytechnic University Department of Anatomy Li Ka Shing Faculty of Medicine The University of Hong Kong The State Key Laboratory of Brain and Cognitive Sciences The University of Hong Kong Research Centre of Heart Brain Hormone and Healthy Aging Faculty of Medicine The University of Hong Kong GHM Institute of CNS Regeneration Jinan University

Psychiatric illness, such as affective disorders, anxiety disorders and schizophrenia, exerts exceptional personal burden on affected individuals. Although not physically noticeable, these disorders cost enormously on ones' family and society. Currently pharma-ceutical and psychological treatments are generally accepted as effective for psychiatric disorders, while the exact mechanisms underlying the treatment efficacy, etiology and neurobiology of the disorders remain elusive. In the past decade, "neurogenic hy-pothesis" emerged as an attempt to explain the nature of psychiatric illness. The origination of the hypothesis is based on several pre-clinical and clinical observations. First, stress, which is a common risk factor of the disorders, was found to suppress neurogenesis; second, treatment for the illnesses like antidepressants and antipsychotics were shown to improve neurogenesis and behavioral deficits simultaneously; and third, the therapeutic effect of antidepressants was abolished in animal models when neuro-genesis was blocked. Increasing efforts were invested to determine whether neurogenesis is a key to the understanding and treatment of psychiatric disorders, although contrasting results are also found and thus the importance of neurogenesis remains a matter of debate. The present chapter will discuss the recent findings about the involvement of neurogenesis in major depression, anxiety disorders and schizophrenia, and whether neurogenesis would be a potential target for development of the treatment in the future.

关键词：精神疾病神经发生假说精神分裂症心理治疗临床观察抗抑郁药治疗效果

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Current and Future Treatment of Hepatocellular Carcinoma:An Updated Comprehensive Review

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Journal of Clinical and Translational Hepatology 2018年第1期6卷 69-78页

作者： Saleh Daher Muhammad Massarwa Ariel A. benson Tawfik Khoury Gastroenterology and Liver Units Department of MedicineHadassah-Hebrew University Medical CenterJerusalemIsrael

Hepatocellular carcinoma(HCC)is among the leading causes of cancer-related *** principal treatment is surgical resection or liver transplantation,depending on whether the patient is a suitable transplant ***,in most patients with HCC the diagnosis is often late,thereby excluding the patients from definitive surgical *** treatment includes sorafenib,which is the most commonly used systemic therapy;although,it has been shown to only minimally impact patient survival by several *** and radiotherapy are generally *** to the poor prognosis of patients with HCC,newer treatments are needed with several being in development,either in preclinical or clinical *** this review article,we provide an update on the current and future medical and surgical management of HCC.

关键词： HCC Treatments Sorafenib Mortality

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Grain Refinement of Primary Si in Hypereutectic Al-Si Alloys Using P-based Master Alloys

Grain Refinement of Primary Si in Hypereutectic Al-Si Alloys...

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作者： benson Kihono Njuguna 大连理工大学

学位级别：硕士

过共晶铝硅合金因具有低的热膨胀系数和高的高温力学性能等优点被广泛应用于汽车、航空航天等领域,然而合金中粗大的初晶硅相易形成裂纹源并导致断裂,严重影响了合金的力学性能。磷变质处理是减小初晶硅尺寸、改善其形貌的重要方法,常... 详细信息

过共晶铝硅合金因具有低的热膨胀系数和高的高温力学性能等优点被广泛应用于汽车、航空航天等领域,然而合金中粗大的初晶硅相易形成裂纹源并导致断裂,严重影响了合金的力学性能。磷变质处理是减小初晶硅尺寸、改善其形貌的重要方法,常见的含磷变质剂有Al-P、Al-Si-P、Cu-P等中间合金。本文以过共晶Al-24Si（质量百分数,下同）合金为研究对象,采用金相显微镜（OM,Optical Microscope）、场发射扫描电镜（FESEM,Field Emission Scanning Electron Microscope）、X射线衍射仪（X-Ray Diffraction）等分析手段研究了Si-3P、Al-10Si-2Fe-3P和Si-25Mn-10P中间合金的微观组织及其对初晶硅的晶粒细化作用。分别在810℃、820℃和840℃条件下向Al-24Si合金熔体中添加三种中间合金,并对比分析不同保温时间（30min、60min、90min）下Al-24Si合金的微观组织及初晶硅的尺寸,从而获得中间合金及工艺参数对初晶硅细化作用的影响。本文取得的主要研究结果为:（1）Si-3P、Si-25Mn-10P和Al-10Si-2Fe-3P中间合金中的磷化物分别为SiP、MnP和AlP,三种中间合金均为过共晶Al-24Si合金的有效晶粒细化剂,经过细化处理后合金中初晶硅的尺寸由花瓣状变为细小块状。保温时间为30min时,中间合金的晶粒细化效果最优,随保温时间的延长,其晶粒细化效果逐渐衰退。（2）经过Si-25Mn-10P中间合金细化后的初晶硅的平均尺寸可达到18μm,其晶粒细化效果明显优于Si-3P和Al-10Si-2Fe-3P中间合金,这可能是由中间合金存在高活性的MnP相导致的。此外,提高熔炼温度有利于提升Si-25Mn-10P中间合金的晶粒细化效果。

关键词：铝硅合金初晶硅晶粒细化中间合金 AlP

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Neoadjuvant treatment of rectal cancer:where are we now?

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Gastroenterology Report 2016年第3期4卷 206-209,I0002页

作者： Aparna Kalyan Shaina Rozelle Al benson III Developmental Therapeutics Program of Division of Hematology&Oncology Robert H.Lurie Comprehensive Cancer Center of Northwestern UniversityChicagoIL USA Division of Hematology&Oncology Robert H.Lurie Comprehensive Cancer Center of Northwestern UniversityChicagoIL USA

Introduction Colorectal cancer is the third leading cause of cancer-related mortality in the United States[1].Of this group of patients,approximately 39000 cases of rectal cancer were reported in the US in 20151].Treatment of rectal cancer truly requires combinatorial therapy with surgery,chemotherapy and radiation(RT),which now comprise the cornerstone of treatment for rectal cancer.

关键词： rectal cancer neoadjuvant chemoradiation 5-fluorouracil local recurrence

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