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A NEW MODEL FOR PEBBLE BEACH tRACER DISPERSAL

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Acta Oceanologica Sinica 1987年第2期 229-234页

作者： a.t.williams UK CF37 1DL Department of Science PONtYPRIDD Coastal Research Unit the Polytechnic of Wales Mid Glamorgan

A series of eight tracer experiments were carried out over one year (1983) on a low energy, macro-tidal beach in South Wales, UK. tracer movement was monitored and 30 pebbles adjacent to coloured tracer pebbles were measured. Measurements were of the A, B, and C axes, roundness, Maximum Projection Sphericity and Oblate-Prolate indices. Analysis shows that through time, the percentage rejection of these properties increased. It is theorised that the surface tracers are ’misfits’ or ’rejects’ which have not found their equilibrium position in the pebble facies.

关键词： tracer A NEW MODEL FOR PEBBLE BEACH tRACER DISPERSAL

three-stage pyrolysis–steam reforming–water gas shift processing of household,commercial and industrial waste plastics for hydrogen production

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Waste Disposal and Sustainable Energy 2024年第1期6卷 25-37页

作者： Rayed Alshareef Robert Sait-Stewart Mohamad A.Nahil Paul t.williams School of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Five common single plastics and nine different household,commercial and industrial waste plastics were processed using a three-stage(i)pyrolysis,(ii)catalytic steam reforming and(iii)water gas shift reaction system to produce *** of plastics produces a range of different hydrocarbon species which are subsequently catalytically steam reformed to produce H_(2)and CO and then undergo water gas shift reaction to produce further H_(2).the process mimics the commercial process for hydrogen production from natural *** of the single polyalkene plastics(high-density polyethylene(HDPE),low-density polyethylene(LDPE),and polypropylene(PP))produced similar H_(2)yields between 115 mmol and 120 mmol per gram *** though PS produced an aromatic product slate from the pyrolysis stage,further stages of reforming and water gas shift reaction produced a gas yield and composition similar to that of the polyalkene plastics(115 mmol H_(2)per gram plastic).PEt gave significantly lower H_(2)yield(41 mmol per gram plastic)due to the formation of mainly CO,CO_(2)and organic acids from the pyrolysis stage which were not conducive to further reforming and water gas shift reaction.A mixture of the single plastics typical of that found in municipal solid waste produced a H_(2)yield of 102 mmol per gram *** the gas yields and composition from the single plastics enabled an estimation of the yields from a simulated waste plastic mixture and a‘real-world’waste plastic mixture to be *** different household,commercial and industrial waste plastic mixtures produced H_(2)yields between 70 mmol and 107 mmol per gram *** H_(2)yield and gas composition from the single waste plastics gave an indication of the type of plastics in the mixed waste plastic samples.

关键词： Waste plastic Hydrogen Catalyst Pyrolysis reforming Water gas shift

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计算机模拟扫描电镜颗粒边缘粗糙度外貌特征

宝石和宝石学杂志(中英文) 1988年第3期 19-19页

作者： a.t.williams 熊文俊

各种石英颗粒表面特征的发育与否,是任何扫描电镜分析重建地质环境的基础,对于在石英颗粒表面获得的许多可见特征来说,虽然已有许多"清单"(Krinsley和Donahue,1968:Cater,1984),但是,专门检测技术的有效性还是一个争论的问题.由这类分... 详细信息

各种石英颗粒表面特征的发育与否,是任何扫描电镜分析重建地质环境的基础,对于在石英颗粒表面获得的许多可见特征来说,虽然已有许多"清单"(Krinsley和Donahue,1968:Cater,1984),但是,专门检测技术的有效性还是一个争论的问题.由这类分析获得的最为重要的物理参数之一是边缘磨蚀,因为圆度值是一种发现于石英砂颗粒的主要形态特征.例如,1984年Goudie和Bull发现两类非洲沉积物之间的主要差异是,在深度风化剖面中总体缺乏边缘磨蚀颗粒,并以此为基础建立了该研究区的斜坡

关键词：石英颗粒预处理前处理座标颗粒形状扫描电镜

生长阻滞特异性转录因子5剪接变异体GAS5_O1增强慢性髓系白血病细胞对伊马替尼的敏感性

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中国生物化学与分子生物学报 2024年第3期40卷 348-361页

作者：张斯玮 Gwyn t.williams 西安医学院基础医学部生物化学与分子生物学教研室西安710021 西安医学院西安市病原微生物与肿瘤免疫重点实验室西安710021 School of Life Sciences Keele UniversityStaffordshireUK

在多种肿瘤中,生长阻滞特异性转录因子5(growth-arrest specific transcript 5,GAS5)高表达与患者的良好生存期相关。GAS5存在多种剪接变异体,本研究探讨GAS5部分剪接变异体在髓系白血病细胞系中的表达模式。并基于对凋亡诱导敏感的慢... 详细信息

在多种肿瘤中,生长阻滞特异性转录因子5(growth-arrest specific transcript 5,GAS5)高表达与患者的良好生存期相关。GAS5存在多种剪接变异体,本研究探讨GAS5部分剪接变异体在髓系白血病细胞系中的表达模式。并基于对凋亡诱导敏感的慢性髓系白血病(chronic myeloid leukemia,CML)细胞系K562,研究GAS5部分剪接变异体对K562细胞自身增殖、凋亡以及对靶向药物伊马替尼(imatinib,IM)的敏感性的影响。反转录PCR结果显示,GAS5剪接模式在髓系白血病细胞系HL-60、K562、NB4和KASUMI-1之间未见明显差异。相较于指数增长期,GAS5_AE表达水平在细胞密度引起的生长停滞期有一定程度的累积。通过核转染,将GAS5剪接变异体(pcDNA3-GAS5_1B、-GAS5_2B、-GAS5_3A、-GAS5_4A、-GAS5_O1或-GAS5_AE)转入K562细胞的单克隆株中。通过台盼蓝染色、吖啶橙染色后进行细胞计数,克隆形成实验检测细胞集落形成能力。结果与对照组相比,瞬时转染GAS5剪接变异体并无抑制细胞的基础增殖或增强细胞对药物的敏感性。建立GAS5_O1的稳定转染株,延长培养时程并计算倍增时间,发现GAS5_O1的表达水平和倍增时间成正比(R^(2)=0.5692)。在稳转株O1-C8中观察到GAS5_O1可促进IM引起的细胞生长抑制(56.94%±2.84%vs.36.07%±2.32%,P<0.05)和凋亡(29.33%±1.30%vs.52.00%±2.52%,P<0.05)。上述结果表明,GAS5_O1的上调可能增加CML细胞的倍增时间,并使CML细胞对IM处理敏感。

关键词：生长阻滞特异性转录因子5 剪接变异体慢性髓系白血病凋亡

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Rapid Green Synthesis of Silver Nanoparticles by Reishi and their Antibacterial Activity and Mechanisms

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Journal of Biomaterials and Nanobiotechnology 2024年第3期15卷 51-63页

作者： Akamu J. Ewunkem t’nasia Priester Desia williams Bailey Ariyon Ilunga tshimanga Brittany Justice Dinesh K. Singh Department of Biological Sciences Winston-Salem State University Winston-Salem North Carolina USA

Nanotechnology is a rapidly growing field in biomedical engineering with references to efficiency, safety, and cost-effective approaches. Herein, the objective of this study was to examine an innovative approach to rapidly synthesis silver nanoparticles from an aqueous extract of medicinal mushroom Ganoderma lucidum (also known as reishi). the structural and dimensional dispersion of the biosynthesized silver nanoparticles from reishi was confirmed by UV-Vis spectrophotometer (UV-Vis) and Scanning Electron Microscopy (SEM) analysis. Additionally, the biosynthesized silver nanoparticles from resihi were used to explore their potential antimicrobial activity against Staphylococcus aureus and Micrococcus luteus and Escherichia coli and Klebsiella pneumoniae. the results from this study revealed that the silver nanoparticles mediated by reishi adopted a spherical shape morphology with sizes, less than 100 nm and revealed strong absorption plasmon band at 440 nm. Furthermore, the biosynthesized silver nanoparticles from reishi exhibited antibacterial activity against the tested S. aureus and M. luteus and E. coli and K. pneumoniae by altering their morphology which signifies their biomedical potential.

关键词： Nanotechnology Reishi Nanoparticles Antimicrobial Green Synthesis

Natural Products and Antiviral Resistance

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Advances in Microbiology 2024年第7期14卷 366-388页

作者： Erute Magdalene Adongbede Janak Raj Khatiwada Rishipal Rastrapal Bansode Leonard Lamont williams Department of Botany University of Lagos Lagos Nigeria Center for Excellence in Post-Harvest technologies North Carolina A & T State University Kannapolis North Carolina USA

Viral diseases are minacious with the potential for causing pandemics and treatment is complicated because of their inherent ability to mutate and become resistant to drugs. Antiviral drug resistance is a persistent problem that needs continuous attention by scientists, medical professionals, and government agencies. to solve the problem, an in-depth understanding of the intricate interplay between causes of antiviral drug resistance and potential new drugs specifically natural products is imperative in the interest and safety of public health. this review delves into natural product as reservoir for antiviral agents with the peculiar potentials for addressing the complexities associated with multi-drug resistant and emerging viral strains. An evaluation of the mechanisms underlying antiviral drug activity, antiviral drug resistance is addressed, with emphasis on production of broad-spectrum antiviral agents from natural sources. there is a need for continued natural product-based research, identification of new species and novel compounds.

关键词： Drug Resistance Resistance Mechanisms Phytochemicals Broad-Spectrum Drugs Antiviral Agents

Granular activated carbons from palm nut shells for gold di-cyanide adsorption

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International Journal of Minerals,Metallurgy and Materials 2013年第2期20卷 172-179页

作者： William K.Buah Paul t.williams Energy Research Institute The University of LeedsLeeds LS2 9JTUnited Kingdom

Granular activated carbons were produced from palm nut shells by physical activation with steam. the proximate analysis of palm nut shells was investigated by thermogravimetric analysis, and the adsorption capacity of the activated carbons, produced as a result of shell pyrolysis at 600℃ followed by steam activation at 900℃ in varying activation times, was evaluated using nitrogen adsorption at 77 K. Applicability of the activated carbons for gold dicyanide adsorption was also investigated. Increasing the activation hold time with the attendant increase in the degree of carbon burn-off results in a progressive increase in the surface area of the activated carbons, reaching a value of 903.1 m2/g after activation for 6 h. the volumes of total pores, mieropores, and mesopores in the activated carbons also increase progressively with the increasing degree of carbon burn-off, resulting from increasing the activation hold time. the gold di-cyanide adsorption of the activated carbons increases with the rise of pore volume of the activated carbons. the gold di-cyanide adsorption of palm nut shell activated carbon obtained after 6-h activation at 900℃ is superior to that of a commercial activated carbon used for gold di-cyanide adsorption.

关键词： activated carbon adsorption gold cyanides processing pyrolysis

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Effects of local compositional and structural disorder on vacancy formation in entropy-stabilized oxides from first-principles

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npj Computational Materials 2022年第1期8卷 909-915页

作者： Sieun Chae Logan williams Jihang Lee John t.Heron Emmanouil Kioupakis Department of Materials Science and Engineering University of MichiganAnn ArborMIUSA

Entropic stabilization has evolved into a strategy to create new oxide materials and realize novel functional properties engineered through the alloy *** an atomistic understanding of these properties to enable their design,however,has been challenging due to the local compositional and structural disorder that underlies their fundamental structure-property ***,we combine high-throughput atomistic calculations and linear regression algorithms to investigate the role of local configurational and structural disorder on the thermodynamics of vacancy formation in (MgCoNiCuZn)O-based entropy-stabilized oxides (ESOs) and their influence on the electrical *** find that the cation-vacancy formation energies decrease with increasing local tensile strain caused by the deviation of the bond lengths in ESOs from the equilibrium bond length in the binary *** oxygen-vacancy formation strongly depends on structural distortions associated with the local configuration of chemical *** in ESOs exhibit deep thermodynamic transition levels that inhibit electrical *** applying the charge-neutrality condition,we determine that the equilibrium concentrations of both oxygen and cation vacancies increase with increasing Cu mole *** results demonstrate that tuning the local chemistry and associated structural distortions by varying alloy composition acts an engineering principle that enables controlled defect formation in multi-component alloys.

关键词： alloy structural vacancy

Decomposition of biomass gasification tar model compounds over waste tire pyrolysis char

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Waste Disposal and Sustainable Energy 2022年第2期4卷 75-89页

作者： Amal S.Al-Rahbi Paul t.williams Present address:Applied Sciences Department Higher College of TechnologyUniversity of Technology and Applied SciencesMuscatSultanate of Oman School of Chemical and Process Engineering University of LeedsLeedsLS29JTUK

Gasification of biomass produces a syngas containing trace amounts of viscous hydrocarbon tar,which causes serious problems in downstream pipelines,valves and processing *** study focuses on the use of tire-derived pyrolysis char for tar conversion using biomass tar model compounds representative of *** catalytic decomposition of tar model compounds,including methylnaphthalene,furfural,phenol,and toluene,over tire char was investigated using a fixed bed reactor at a bed temperature of 700℃and 60 min time on *** influence of temperature,reaction time,porous texture,and acidity of the tire char was investigated with the use of methylnaphthalene as the tar model *** tar model compounds were found to have higher conversion than those containing a single or multi-aromatic *** reactivity of tar compounds followed the order of furfural>phenol>toluene>*** conversion of the model compounds in the presence of the tire char was much higher than tar thermal *** production increased dramatically with the introduction of tire *** H_(2)potential for the studied tar model compounds was found to be in the range of 40%–50%.the activity of tire char for naphthalene removal was compared with two commercial activated carbons possessing a very well-developed porous *** results suggest that the influence of Brunauer-Emmett-teller surface area of the carbon on tar cracking is negligible compared with the mineral content in the carbon samples.

关键词： Biomass Gasification Syngas tar tire Char