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A kinetic model for a single step biodiesel production from a high free fatty acid (FFA) biodiesel feedstock over a solid heteropolyacid catalyst

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Green Energy & Environment 2019年第3期4卷 328-341页

作者： Aashish Gaurav Stéphane Dumas Chau T.q.Mai Flora T.T.ng Department of Chemical Engineering University of Waterloo

Production of biodiesel from yellow grease(waste cooking oil and waste animal fats) is fast emerging as a promising alternative to address the twin challenges before the biodiesel industry today-fluctuation in prices of vegetable oil and the food versus fuel debate. Yellow grease has a high percentage of free fatty acids(FFA) and proves to be an unsuitable feedstock for biodiesel production from commercially viable alkalicatalyzed production systems due to saponification problems.'Green' methodologies based on heterogeneous solid acid catalyzed reactions have the potential to simultaneously promote esterification and transesterification reactions of yellow grease to produce biodiesel without soap formation and offer easy catalyst separation without generation of toxic streams. This paper presents kinetic studies for the conversion of model yellow grease feeds to biodiesel using a heteropolyacid supported on alumina(HSiw/Al2O3) using a batch autoclave. Three model yellow grease feeds were prepared using canola oil with added FFA such as palmitic, oleic and linoleic acid. A pseudo homogeneous kinetic model for the parallel esterification and transesterification was developed. The rate constants and activation parameters for esterification and transesterification reactions for the model yellow grease feeds were determined. The rate constants for esterification are higher than the transesterification rate constants. The kinetic model was validated using the experimental biodiesel data obtained from processing a commercial yellow grease feed. The kinetic model could be used to design novel processes to convert various low-value waste oils, fats and non-food grade oils to sustainable biodiesel.

关键词： Yellow grease Canola oil Free fatty acids Heteropolyacid Kinetics for esterification and transesterification

青藏高原及其周边新近纪综合地层、生物群与古地理演化

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中国科学：地球科学 2024年第4期54卷 1343-1378页

作者：邓涛方小敏李强王世骐吴飞翔侯素宽马姣江左其杲孙丹辉郑妍史勤勤孙博阳李录中国科学院古脊椎动物与古人类研究所中国科学院脊椎动物演化与人类起源重点实验室北京100044 中国科学院生物演化与环境卓越创新中心北京100044 中国科学院大学地球与行星科学学院北京100049 中国科学院青藏高原研究所中国科学院青藏高原地球科学卓越创新中心北京100101 北京大学地球与空间科学学院造山带与地壳演化教育部重点实验室北京100871

青藏高原在新近纪的显著隆升对东亚乃至全球的气候环境产生了巨大的影响,因此,建立青藏高原新近纪地层框架对地球科学各领域的研究都有重要的意义.国际新近纪年代地层系统以海相为标准,分为中新统的6个阶和上新统的2个阶.新生代以来,陆... 详细信息

青藏高原在新近纪的显著隆升对东亚乃至全球的气候环境产生了巨大的影响,因此,建立青藏高原新近纪地层框架对地球科学各领域的研究都有重要的意义.国际新近纪年代地层系统以海相为标准,分为中新统的6个阶和上新统的2个阶.新生代以来,陆相地层在陆地上所占的比例迅速增加,到新近纪时已远远超过海相地层,在青藏高原及其周边地区几乎全部为陆相地层.中国的中新统包括5个阶,上新统包括2个阶,除中中新统的通古尔阶以15Ma为底界外,其余各阶都与对应的国际海相阶具有相同的古地磁定义和时限.哺乳动物化石在新生代陆相地层的划分对比中占有非常重要的地位,在新近系尤其倚重于啮齿类、食肉类、长鼻类、奇蹄类和偶蹄类化石.青藏高原有不少地层出露好且富含哺乳动物化石的盆地,新近系谢家阶和灞河阶的底界层型剖面分别位于西宁盆地和临夏盆地,并有精细的古地磁定年与哺乳动物化石相互配合,其余各阶的底界在青藏高原也可以有效确定.东亚地区许多哺乳动物首现属出现在青藏高原及其周边地区,在东北缘的临夏盆地和西南缘的西瓦立克地区尤为典型,其中,西瓦立克的原恐象Prodeinotherium首现于中新统底界,旧大陆最早的三趾马Hipparion首现于临夏盆地的灞河阶底界.对青藏高原及其周缘地区新生代沉积物及其所含的哺乳动物化石进行的牙釉质和古土壤碳氧同位素分析重建了气候环境背景及植被发育特征,发现其既与全球变化相关,又有地区性的特点.根据碳同位素变化得到的晚中新世C4植物扩张事件证据来自于青藏高原南缘,但形成鲜明对比的是,多个食草哺乳动物类群和古土壤碳酸盐及有机质的δ13C指示在青藏高原北缘直到新近纪末期仍然缺少明确或显著的C4植物信号.δ^(18)O分析显示在新生代存在几次重大的气候变化事件,尤其是晚中新世末期约7Ma的δ^(18)O正漂指示了青藏高原南北两侧向更干旱环境的转变.青藏高原在晚中新世的强烈隆升强化了海陆热力对比,由此加强了季风环流并导致C4植被在南亚扩张,但能够为中国北方带来大气降水和C4植物适宜气候的东亚夏季风还不足以影响到青藏高原北部地区.青藏高原在中新世整体上已上升至海拔3000m左右,成为阻碍大型哺乳动物交流的屏障;至上新世达到4000m以上的现代海拔高度,由此形成冰冻圈环境,导致冰期动物群祖先类型出现.

关键词：青藏高原新近系陆相地层哺乳动物化石古地磁

Effect of base Material on Microstructure and Texture Evolution of a Ti–6Al–4V Electron-beam welded Joint

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Acta Metallurgica Sinica(English Letters) 2017年第5期30卷 499-504页

作者： G.q.w.ng Z.b.Zhao b.b.Yu J.R.Liu q.J.w.ng J.H.Zhang R.Yang J.w.Li School of Materials Science and Engineering University of Science and Technology of China Institute of Metal Research Chinese Academy of Sciences Science and Technology on Power beam Processes Laboratory Beijing Aeronautical Manufacturing Technology Research Institute

The effect of base material（bM） on microstructure and crystallographic orientation evolution of a Ti–6Al–4V electron-beam welded joint was investigated. Meanwhile, the crystallographic orientation of prior b grains was studied by advanced electron backscattered diffraction data processing. The inhomogeneity of microstructure within welded joint was formed due to the different microstructures of bM. by comparing microstructure details of the welded joint, including microstructure morphology and crystallographic orientation with those of the base material, it can be found that both the microstructure morphology and crystallographic orientation of the Ebw joint would be controlled by bM.

关键词： Electron-beam welding Titanium alloys Prior b orientation Microstructure Texture

Forced Convective Heat Transfer and Pressure Drop of Air Flow.ng in a Rectangle Duct with Cross-Ribs on the Opposite walls

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Journal of Thermal Science 2002年第3期11卷 259-270页

作者： b.Deng T.T.w.ng w.q.Tao School of Power and Energy Xi’an Jiaotong University Xi’an China Department of Mechanical Engineering The Hong Kong Polytechnic University Hong Kong

Experiments were conducted to investigate the forced convective heat transfer and flow friction of turbulent airflow in a rectangular duct with cross-ribs attached at the two principal walls in the Reynolds number range from 5000 to 40000. The effect of the rib cross angle (45° 60° 75° and the height (4 mm, 5 mm) of the cross-ribs on the forced convection and flow friction were tested. Non-dimensional correlations for the duct average Nusselt number and friction factor of cross-ribs duct were developed from the test data. Experiments were also conducted for the corresponding parallel ribs to compare their relative performance. The experimental results show that both of the convective heat transfer coefficient and friction factor were increased with cross-ribs, with 45°cross-ribs being the best. Compared with parallel ribs normal to the flow direction under identical flow rate and identical pumping power constraints, the cross-ribs can enhance heat transfer in the lower Reynolds number region, while

关键词： cross-ribs forced convection heat transfer enhancement.

Stochastic averaging of quasi integrable and resonant Hamiltonian systems excited by fractional Gaussian noise with Hurst index 1/2

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Acta Mechanica Solida Sinica 2017年第1期30卷 11-19页

作者： q.F.Lü M.L.Deng w.q.Zhu Department of Mechanics State Key Laboratory of Fluid Power and Mechatronic SystemsKey Laboratory of Soft Machines and Smart Devices of Zhejiang ProvinceZhejiang University

A stochastic averaging method of quasi integrable and resonant Hamiltonian systems under excitation of fractional Gaussian noise （fGn） with the Hurst index 1/2 〈 H 〈 1 is proposed. First, the definition and the basic property of fGn and related fractional brownian motion （ibm） are briefly introduced. Then, the averaged fractional stochastic differential equations （SDEs） for the first integrals and combinations of angle variables of the associated Hamiltonian systems are derived. The stationary probability density and statistics of the original systems are then obtained approximately by simulating the averaged SDEs numerically. An example is worked out to illustrate the proposed stochastic averaging method. It is shown that the results obtained by using the proposed stochastic averaging method and those from digital simulation of original system agree well.

关键词： quasi integrable and resonant Hamiltonian system Fractional brownian motion Fractional Gaussian noise Stochastic averaging method Internal resonant

Determination of the number ofψ(3686)events taken at bESⅢ

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Chinese Physics C 2024年第9期48卷 8-20页

作者： M.Ablikim M.N.Achasov P.Adlarson O.Afedulidis X.C.Ai R.Aliberti A.Amoroso q.An Y.bai O.bakina I.balossino Y.ban H.-R.bao V.batozskaya K.begzsuren N.berger M.berlowski M.bertani D.bettoni F.bianchi E.bianco A.bortone I.boyko R.A.briere A.brueggemann H.Cai X.Cai A.Calcaterra G.F.Cao N.Cao S.A.Cetin J.F.Chang G.R.Che G.Chelkov C.Chen C.H.Chen Chao Chen G.Chen H.S.Chen H.Y.Chen M.L.Chen S.J.Chen S.L.Chen S.M.Chen T.Chen X.R.Chen X.T.Chen Y.b.Chen Y.q.Chen Z.J.Chen Z.Y.Chen S.K.Choi G.Cibinetto F.Cossio J.J.Cui H.L.Dai J.P.Dai A.Dbeyssi R.E.de boer D.Dedovich C.q.Deng Z.Y.Deng A.Denig I.Denysenko M.Destefanis F.De Mori b.Ding X.X.Ding Y.Ding Y.Ding J.Dong L.Y.Dong M.Y.Dong X.Dong M.C.Du S.X.Du Y.Y.Duan Z.H.Duan P.Egorov Y.H.Fan J.Fang J.Fang S.S.Fang w.X.Fang Y.Fang Y.q.Fang R.Farinelli L.Fava F.Feldbauer G.Felici C.q.Feng J.H.Feng Y.T.Feng M.Fritsch C.D.Fu J.L.Fu Y.w.Fu H.Gao X.b.Gao Y.N.Gao Yang Gao S.Garbolino I.Garzia L.Ge P.T.Ge Z.w.Ge C.Geng E.M.Gersabeck A.Gilman K.Goetzen L.Gong w.X.Gong w.Gradl S.Gramigna M.Greco M.H.Gu Y.T.Gu C.Y.Guan Z.L.Guan A.q.Guo L.b.Guo M.J.Guo R.P.Guo Y.P.Guo A.Guskov J.Gutierrez K.L.Han T.T.Han F.Hanisch X.q.Hao F.A.Harris K.K.He K.L.He F.H.Heinsius C.H.Heinz Y.K.Heng C.Herold T.Holtmann P.C.Hong G.Y.Hou X.T.Hou Y.R.Hou Z.L.Hou b.Y.Hu H.M.Hu J.F.Hu S.L.Hu T.Hu Y.Hu G.S.Huang K.X.Huang L.q.Huang X.T.Huang Y.P.Huang T.Hussain F.Hölzken N.Hüsken N.in der wiesche J.Jackson S.Janchiv J.H.Jeong q.Ji q.P.Ji w.Ji X.b.Ji X.L.Ji Y.Y.Ji X.q.Jia Z.K.Jia D.Jiang H.b.Jiang P.C.Jiang S.S.Jiang T.J.Jiang X.S.Jiang Y.Jiang J.b.Jiao J.K.Jiao Z.Jiao S.Jin Y.Jin M.q.Jing X.M.Jing T.Johansson S.Kabana N.Kalantar-Nayestanaki X.L.Kang X.S.Kang M.Kavatsyuk b.C.Ke V.Khachatryan A.Khoukaz R.Kiuchi O.b.Kolcu b.Kopf M.Kuessner X.Kui N.Kumar A.Kupsc w.Kühn J.J.Lane P.Larin L.Lavezzi T.T.Lei Z.H.Lei M.Lellmann T.Lenz C.Li C.Li C.H.Li Cheng Li D.M.Li F.Li G.Li H.b.Li H.J.Li H.N.Li Hui Li J.R.Li J.S.Li Ke Li L.J.Li L.K.Li Lei Li M.H.Li P.R.Li q.M.Li q.X.Li R.Li S.X.Li T.Li w.D.Li w.G.Li X.Li X.H.Li X.L.Li X.Z.Li Xi Institute of High Energy Physics Beijing 100049China beihang University Beijing 100191China bochum Ruhr-University D-44780BochumGermany budker Institute of Nuclear Physics Sb RAS(bINP) Novosibirsk 630090Russia Carnegie Mellon University PittsburghPennsylvania 15213USA Central China Normal University Wuhan 430079China Central South University Changsha 410083China China Center of Advanced Science and Technology Beijing 100190China China University of Geosciences Wuhan 430074China Chung-Ang University Seoul06974Republic of Korea COMSATS University Islamabad Lahore CampusDefence RoadOff Raiwind Road54000LahorePakistan Fudan University Shanghai 200433China GSI Helmholtzcentre for Heavy Ion Research GmbH D-64291DarmstadtGermany Guangxi Normal University Guilin 541004China Guangxi University Nanning 530004China Hangzhou Normal University Hangzhou 310036China Hebei University Baoding 071002China Helmholtz Institute Mainz Staudinger Weg 18D-55099MainzGermany Henan Normal University Xinxiang 453007China Henan University Kaifeng 475004China Henan University of Science and Technology Luoyang 471003China Henan University of Technology Zhengzhou 450001China Huangshan College Huangshan 245000China Hunan Normal University Changsha 410081China Hunan University Changsha 410082China Indian Institute of Technology Madras Chennai 600036India Indiana University BloomingtonIndiana 47405USA INFN Laboratori Nazionali di Frascati (A)INFN Laboratori Nazionali di FrascatiI-00044FrascatiItaly(B)INFN Sezione di PerugiaI-06100PerugiaItaly(C)University of PerugiaI-06100PerugiaItaly INFN Sezione di Ferrara (A)INFN Sezione di FerraraI-44122FerraraItaly(B)University of FerraraI-44122FerraraItaly Inner Mongolia University Hohhot 010021China Institute of Modern Physics Lanzhou 730000China Institute of Physics and Technology Peace Avenue 54BUlaanbaatar 13330Mongolia Instituto de Alta Investigación Universidad de TarapacáCasilla 7DArica 1000000Chile Jilin University Changchun 130012China Joha

The number ofψ(3686)events collected by the bESⅢdetector during the 2021 run period is determined to be(2259.3±11.1)×10~6 by counting inclusiveψ(3686)hadronic *** uncertainty is systematic and the statistical uncertainty is ***,the numbers ofψ(3686)events collected during the 2009 and 2012run periods are updated to be(107.7±0.6)×10~6 and(345.4±2.6)×10~6,*** numbers are consistent with the previous measurements within one standard *** total number ofψ(3686)events in the three data samples is(2712.4±14.3)×10~6.

关键词： ψ(3686) inclusive process Hadronic events bESⅢdetector

Additively manufactured Ti–Ta–Cu alloys for the next-generation load-bearing implants

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International Journal of Extreme Manufacturing 2024年第1期6卷 353-374页

作者： Amit bandyopadhyay Indranath Mitra Sushant Ciliveri Jose D Avila william Dernell Stuart b Goodman Susmita bose w.M.Keck biomedical Materials Research Laboratory School of Mechanical and Materials EngineeringWashington State UniversityPullmanWA 99164United States of America Veterinary Clinical Sciences College of Veterinary MedicineWashington State UniversityPullmanWA 99164United States of America Department of Orthopedic Surgery Stanford University Medical CenterRedwood CityCA 94063United States of America

bacterial colonization of orthopedic implants is one of the leading causes of failure and clinical complexities for load-bearing metallic implants. Topical or systemic administration of antibiotics may not offer the most efficient defense against colonization, especially in the case of secondary infection, leading to surgical removal of implants and in some cases even limbs. In this study, laser powder bed fusion was implemented to fabricate Ti3Al2V alloy by a 1:1 weight mixture of CpTi and Ti6Al4V powders. Ti-Tantalum(Ta)–Copper(Cu) alloys were further analyzed by the addition of Ta and Cu into the Ti3Al2V custom alloy. The biological,mechanical, and tribo-biocorrosion properties of Ti3Al2V alloy were evaluated. A 10 wt.% Ta(10Ta) and 3 wt.% Cu(3Cu) were added to the Ti3Al2V alloy to enhance biocompatibility and impart inherent bacterial resistance. Additively manufactured implants were investigated for resistance against Pseudomonas aeruginosa and Staphylococcus aureus strains of bacteria for up to 48 h. A 3 wt.% Cu addition to Ti3Al2V displayed improved antibacterial efficacy, i.e.78%–86% with respect to CpTi. Mechanical properties for Ti3Al2V–10Ta–3Cu alloy were evaluated, demonstrating excellent fatigue resistance, exceptional shear strength, and improved tribological and tribo-biocorrosion characteristics when compared to Ti6Al4V. In vivo studies using a rat distal femur model revealed improved early-stage osseointegration for alloys with10 wt.% Ta addition compared to CpTi and Ti6Al4V. The 3 wt.% Cu-added compositions displayed biocompatibility and no adverse infammatory response in vivo. Our results establish the Ti3Al2V–10Ta–3Cu alloy’s synergistic effect on improving both in vivo biocompatibility and microbial resistance for the next generation of load-bearing metallic implants.

关键词： Ti6Al4V load-bearing implants additive manufacturing 3D printing antibacterial performance

Simulation and experimentation of Propeller-Savonius turbine tested underwater surface

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Clean Energy 2024年第3期8卷 20-33页

作者： Sri wuryanti Teguh Sasono bambang P.Manunggal wahyu b.Mursanto Sugianto Department of Energy Conversion Engineering Politeknik Negeri BandungIndonesia Department of Mechanical Engineering Politeknik Negeri BandungIndonesia

Indonesia’s vast maritime territory offers a unique opportunity for harnessing the potential Energy of seawater *** study explores the effectiveness of a combined Savonius and propeller-type turbine *** Savonius turbine,known for its efficiency in capturing ocean currents due to its large sweep area,is combined with a propeller-type turbine to enhance rotational speed and power generation.A novel approach is employed to induce turbulence and optimize energy extraction,first channeling water through the propeller turbine and then into the Savonius turbine.A comprehensive investigation is conducted through simulations and experimental tests within a controlled tunnel *** study explores the performance of two-bladed and three-bladed Propeller-Savonius configurations at varying inlet water velocities(0.1,0.3,0.6 and 1.0 m/s).The simulation incorporates a turbulence model with 5%intensity and a hydraulic diameter of 0.216 *** indicate that the proposed configuration achieves a maximum power output of 2.0293 w with an impressive efficiency of 63.339%in ***,experimental testing yields a peak efficiency of 61.335%and turbine power of 0.3951 *** findings demonstrate the feasibility of the combined turbine system and highlight the importance of turbulence in optimizing energy extraction from seawater *** research contributes valuable insights into the design and performance of hybrid turbines for harnessing oceanic Energy,emphasizing the potential for sustainable power generation in maritime *** methodology and results presented herein offer a foundation for further exploration and refinement of seawater current energy conversion technologies.

关键词： hydro-turbine propeller-Savonius renewable energy water

颅脑外伤后夸大视力障碍程度残疾等级评定1例

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法医学杂志 2024年第1期40卷 98-100页

作者：李陨石高炜张艳琴徐强沈晓林南京东南司法鉴定中心江苏南京210000 安徽中衡司法鉴定中心安徽合肥230000

1案例1.1简要案情张某,男,57岁,某年7月2日因交通事故受伤,伤后即感视物不清,并住院治疗。现距离伤后已1年余,张某仍觉视物不清,故诉讼至当地法院,申请对其视觉功能的残疾等级进行评定。1.2病史摘要某年7月2日张某因“外伤后头部疼痛伴... 详细信息

1案例1.1简要案情张某,男,57岁,某年7月2日因交通事故受伤,伤后即感视物不清,并住院治疗。现距离伤后已1年余,张某仍觉视物不清,故诉讼至当地法院,申请对其视觉功能的残疾等级进行评定。1.2病史摘要某年7月2日张某因“外伤后头部疼痛伴视物模糊”入住某市人民医院神经外科。查体:额部右侧约2 cm×2 cm擦伤,红肿、压痛伴血性渗出;双眼第一眼位正,左眼外展不到位,双眼结膜无充血,角膜透明,前房深度正常,双侧瞳孔等大等圆,直径均约3 mm,对光反射灵敏,虹膜纹理清,晶体透明,眼底未见明显异常。

关键词：法医学视力颅脑损伤伪装残疾等级评定