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61.
Lewis Base Additives Improve the Zeolite Ferrierite‐Catalyzed Synthesis of Isostearic Acids
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![点击此处可从《Journal of the American Oil Chemists](/ch/ext_images/free.gif)
Helen L. Ngo 《Journal of the American Oil Chemists' Society》2015,92(4):613-619
Isostearic acids (IA) are highly utilized for industrial purposes especially in the area of biolubricants, such as cosmetics and slip additives for polyolefin and related copolymer films. This study was designed to develop a zeolitic catalysis process for efficient IA production through isomerization of fatty acids. The process utilized zeolite protonated Ferrierite with a small amount of base additive to neutralize (i.e., poison) the acidic sites on the external surfaces of the zeolite particles to prevent side reactions. Of the six base additives examined, the proton sponge combined with the zeolite protonated Ferrierite was found to be the most effective for this isomerization. With only 0.5 wt% proton sponge additive to 5.0 wt% Ferrierite, the dimers were successfully suppressed from 20.6 wt% yield to 2.42 wt% with an IA yield of 83.4 wt% and a 98 % conversion. 相似文献
62.
Jianping Zhang Yuying Du Helen Wu Weiguo Pan Jianxing Ren Danmei Hu 《The International journal of environmental studies》2013,70(3):344-359
The PM10 collection efficiency of a wire-cylinder electrostatic precipitator (ESP) was studied by means of a developed mathematical model, including the multi-field coupling between the gas flow field, the particle dynamic field and the electric field, and applying the Deutsch–Anderson Equation. The diffusion charging mechanism was considered due to the diameter range of PM10. The investigated variables were the applied potential, the gas velocity and the particle distribution. Numerical results indicate that the diffusion charging has significant influence on PM10 removal performance and the effect is more obvious with the decreasing diameter, and that the PM10 collection efficiency increases with the increasing applied potential and the increment of collection efficiency is more significant at lower voltage. Moreover, as the gas velocity at inlet decreases, collection efficiency of PM10 will increase. Finally, the overall efficiency increases with increasing the mean diameter of particle distribution. The research results can provide theoretical and technical references for the design of novel ESP aiming at economy and environment protection. 相似文献
63.
The paper takes its starting point from the duality in the Estonian rural landscape shaped by social practices. On the one hand, the changes and management of landscapes follow a political decision. At the same time, the old patterns of semi-legal activity offer a resistant practice. The study is illustrated with the milk trestle, a now-disappeared symbol of recent history in the Soviet countryside. The milk trestles and their role in Estonian country life are studied from a threefold perspective—their functions, meanings and the values behind this symbol. The article is based on ethnographic field work carried out between the years of 2001 and 2002 and traces the phenomenon of how living landscape transforms into deserted landscape; in other words, how story becomes history. The paper shows how the milk trestle landscape functioned as a prolongation of the former landscape behind the ideological layers of the Soviet landscapes. 相似文献
64.
Helen Clare Lingard Keith Townsend Lisa Bradley Kerry Brown 《Construction Management & Economics》2013,31(10):1101-1112
Project‐based construction workers in the Australian construction industry work long and irregular hours and experience higher levels of work‐to‐family conflict and burnout than office‐based workers, giving rise to an interest in alternative work schedules as a means of supporting work–life balance. Alternative work schedules were implemented in four case study construction projects in Australia. Interventions differed between projects, with two implementing a compressed work week, and the others introducing reduced hours schedules (one of which was optional). Data were collected from each case study project, using various combinations of focus groups, surveys, interviews and daily diary collection methods. The results were mixed. The compressed work week appears to have been favourably received where it was introduced. However, waged workers still expressed concerns about the impact on their weekly ‘take‐home’ pay. Attempts to reduce work hours by changing from a six‐ to a five‐day schedule (without extending the length of the working day between Monday and Friday) were less favourably received. Waged workers, in particular, did not favour reduced hours schedules. The results confirm the existence of two distinct labour markets operating in the Australian construction industry and markedly different responses to alternative work schedules, based upon whether workers are waged or salaried. The results clearly show that attempts to improve work–life balance must take the structural characteristics of the industry's labour markets into consideration in the design of interventions. The impact of alternative work schedules is likely to be moderated by institutional working time regimes within the construction industry. 相似文献
65.
Helen Clare Lingard Tracy Cooke Nick Blismas 《Construction Management & Economics》2013,31(5):367-382
Drawing upon an empirical analysis of the design and construction of a food processing facility, a theoretical understanding of the impact of design decision-making on the occupational health and safety (OHS) of construction workers is developed. It is argued that current policy and legislative approaches to Construction Hazard Prevention through Design (CHPtD) are inherently limited because they do not adequately reflect the socio-material complexity of decision-making in construction design. Specifically, the simplistic attribution of responsibility to a single socio-technical actor, ‘the designer’, does not reflect the multiple and disparate influences that impact upon OHS outcomes. Nor do existing CHPtD policy frameworks, management processes and tools recognize the manner in which the interactions and associations between relevant project stakeholders and various non-human artefacts shape (and are also influenced by) the evolution of design decisions. Drawing on actor-network theory (ANT) and using embedded units within a case study approach, the interactions between human actors and non-human artefacts are explored in relation to the design of four components of the food processing facility. The way in which design decisions unfolded and shaped OHS experiences during the construction stage of the project is revealed. The research highlights limitations inherent in current approaches to the management of CHPtD and the need to develop a more robust theoretically based approach to integrating OHS considerations into construction design practice. 相似文献
66.
A survey of construction companies' secondary disability management practices was undertaken in the state of Victoria, Australia. The results indicate that formal rehabilitation and return‐to‐work programmes and practices are not adopted in many companies. Smaller construction firms were less likely to have adopted formal programmes or practices than medium‐to‐large firms. In particular, construction companies reported difficulties in the provision of suitable alternate or light duties for workers returning to work following an injury. Most companies regarded disability management practices to have increased operating costs while yielding little or no benefit in terms of reducing lost workdays. Strategies to overcome some of these impediments to rehabilitation and return‐to‐work in construction are recommended. 相似文献
67.
Helen Meller 《Planning Perspectives》2013,28(1):99-115
Geography, planning and policy making. P. T. Kivell and J. T. Coppock (eds), GeoBooks, Norwich, 1986. 310 pp, £25.00 $41.25, ISBN 0 86094 211 2 Counterurbanization. International case studies of socio‐economic change in the rural areas. Ronald Perry, Ken Dean and Bryan Brown, GeoBooks, Norwich, 1986. 280 pp, £25.00 $41.25, ISBN 0 86094 205 8 The twentieth century American city: problem, promise, and reality. Jon C. Teaford, Johns Hopkins University Press, Baltimore, 1986. 192 pp, $20.00 cloth ISBN 0 8018 3094 X $8.95 paper ISBN 0 8018 3096 6 San Francisco, 1865–1932: politics, power and urban development. William Issel and Robert W. Cherny, University of California Press, Berkeley, 1986. 294 pp, $35.00, ISBN 0 520 05263 3 The limits of power: great fires and the process of city growth in America. Christine Meisner Rosen, University Press, Cambridge, 1986. 395 pp, £30.00, $39.50, ISBN 0 521 30319 2 Critical issues in urban economic development. Volumes I and II. Victor A. Hausner (ed.), Clarendon Press, Oxford, 1986–7. 235 pp and 207 pp, £22.50 each, ISBN 0 19 823226 7 and ISBN 0 19 823268 3 The elusive city; five centuries of design, ambition and miscalculation. Jonathan Barnett, Harper and Row, New York, 1986. 210 pp, $23.50, ISBN 0 06 430377 2 The conservation of ecosystems and species. Gareth E. Jones, Croom Helm, London, 1987. 277 pp, £27.50, ISBN 0 7099 1463 6 Medicine and industrial society. A history of hospital development in Manchester and its region, 1752–1946. John V. Pickstone, University Press, Manchester, 1985. 369 pp, £35.00, ISBN 0 7190 1809 9 The paradox of professionalism: reform and public service in urban America, 1900–1940. Don S. Kirschner, Greenwood Press, Westport, Conn., Contributions in American History, 119, 1986. 195 pp, $32.95, ISBN 0 313 25345 5 An organisational approach to regional planning. Mario Rui Martins, Gower, Aldershot, 1986. 244 pp, £18.50 ISBN 0 566 00515 8 The tenant movement in New York City, 1904–1984. Ronald Lawson (ed.), Rutgers University Press, New Brunswick, New Jersey, 1986 289 pp, $35.00 cloth $15.00 paper, ISBN 0 8135 1158 5 The Scottish thirties. An architectural introduction. Charles McKean, Scottish Academic Press, Edinburgh, 1987. 200 pp, £17.50 hb ISBN 0 7073 0493 8, £8.50 pb ISBN 0 7073 0493 6 Hikaku Toshi Keikaku Josetsu (Introduction to comparative urban planning; land use controls in Britain and the US). Shun‐ichi Watanabe, Sanseido, Tokyo, 1985. 304 pp, ¥3600, ISBN 4 385 30895 0 Arabic‐Islamic cities. Building and planning principles. Besim Selim Hakim, KPI, London, 1986. 192 pp, £35.00, ISBN 0 7103 0094 8 Imagining tomorrow: history, technology, and the American future. Joseph J. Corn (ed.), MIT Press, Cambridge, Massachusetts, 1986. 237 pp, $17.50 cloth, ISBN 0 262 03115 9 相似文献
68.
69.
Integrating legacy soil phosphorus into sustainable nutrient management strategies for future food,bioenergy and water security 总被引:11,自引:0,他引:11
70.
Helen Hejin Park Rachel Heasley Leizhi Sun Vera Steinmann Rafael Jaramillo Katy Hartman Rupak Chakraborty Prasert Sinsermsuksakul Danny Chua Tonio Buonassisi Roy G. Gordon 《Progress in Photovoltaics: Research and Applications》2015,23(7):901-908
Thin‐film solar cells consisting of earth‐abundant and non‐toxic materials were made from pulsed chemical vapor deposition (pulsed‐CVD) of SnS as the p‐type absorber layer and atomic layer deposition (ALD) of Zn(O,S) as the n‐type buffer layer. The effects of deposition temperature and annealing conditions of the SnS absorber layer were studied for solar cells with a structure of Mo/SnS/Zn(O,S)/ZnO/ITO. Solar cells were further optimized by varying the stoichiometry of Zn(O,S) and the annealing conditions of SnS. Post‐deposition annealing in pure hydrogen sulfide improved crystallinity and increased the carrier mobility by one order of magnitude, and a power conversion efficiency up to 2.9% was achieved. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献