Cost effectiveness

About: Cost effectiveness is a research topic. Over the lifetime, 69775 publications have been published within this topic receiving 1531477 citations.

Will we exceed 50% efficiency in photovoltaics?

Abstract: Solar energy is the most abundant and reliable source of energy we have to provide for the multi-terawatt challenge we are facing. Although huge, this resource is relatively dispersed. High conversion efficiency is probably necessary for cost effectiveness. Solar cell efficiencies above 40% have been achieved with multijunction (MJ) solar cells. These achievements are here described. Possible paths for improvement are hinted at including third generation photovoltaics concepts. It is concluded that it is very likely that the target of 50% will eventually be achieved. This high efficiency requires operating under concentrated sunlight, partly because concentration helps increase the efficiency but mainly because the cost of the sophisticated cells needed can only be paid by extracting as much electric power form each cell as possible. The optical challenges associated with the concentrator optics and the tools for overcoming them, in particular non-imaging optics, are briefly discussed and the results and ...

Sustainable Design Through Process Integration: Fundamentals and Applications to Industrial Pollution Prevention, Resource Conservation, and Profitability Enhancement

Abstract: This timely book provides authoritative, comprehensive, and easy-to-follow coverage of the fundamental concepts and practical techniques on the use of process integration to maximize the efficiency and sustainability of industrial processes. Over the past three decades, significant advances have been made in treating, designing, and operating chemical processes as integrated systems. Whether you are a process engineer, an industrial decision maker, or a researcher, this book will be an indispensable resource tool for systematically enhancing process performance and developing novel and sustainable process designs. The book is also ideal for use as a text in an upper level undergraduate or an introductory graduate course on process design and sustainability. This ground breaking reference enhances and reconciles various process and sustainability objectives, such as cost effectiveness, yield improvement, energy efficiency, and pollution prevention. The detailed tools and applications within are written by one of the world's foremost process integration and design experts and will save you time and money. This title allows the reader to methodically develop rigorous targets that benchmark the performance of industrial processes then develop cost-effective implementations. It contains state-of-the-art process integration approaches and applications including graphical, algebraic, and mathematical techniques. It covers applications that include process economics, targeting for conservation of mass and energy, synthesis of innovative processes, retrofitting of existing systems, design and assessment of renewable energy systems, and in-process pollution prevention. It presents fundamentals and step-by-step procedures that can be applied to the design and optimization of new processes as well the retrofitting and operation of existing processes. It explains how pivotal sustainability issues can holistically and methodically be addressed and reconciled. It includes numerous examples and case studies on a broad array of industrial processes and sustainable designs. About the author: Dr Mahmoud El-Halwagi is a professor and holder of the McFerrin Professorship at the Artie McFerrin Department of Chemical Engineering, Texas A&M University. He is internationally recognized for pioneering contributions in the principles and applications of process integration and sustainable design. Dr El-Halwagi has served as a consultant to a wide variety of processing industries. He is the recipient of prestigious research and educational awards including the American Institute of Chemical Engineers Sustainable Engineering forum (AIChE SEF) Research Excellence Award, the Lockheed Martin Excellence in Engineering Teaching Award, The Fluor Distinguished Teaching Award, and the US National Science Foundation's National Young Investigator Award.

Effectiveness and cost-effectiveness of arthroscopic lavage in the treatment of osteoarthritis of the knee: a mixed methods study of the feasibility of conducting a surgical placebo-controlled trial (the KORAL study).

Abstract: Objectives To ascertain the acceptability of a randomised controlled trial comparing arthroscopic lavage with a placebo-surgical procedure for the management of osteoarthritis of the knee; and to assess the practical feasibility of mounting such a multicentre placebo-controlled trial. Design Mixed methods study including: focus groups with surgeons and anaesthetists; focus groups and interviews with potential participants; interviews with chairpersons of UK Multicentre Research Ethics Committees (MRECs); surveys of surgeons and anaesthetists; and a two-centre, three-arm pilot. Setting UK secondary care. Participants Members of the British Association of Surgeons of the Knee and members of the British Society of Orthopaedic Anaesthetists took part in the focus groups and surveys. Surgeons and anaesthetists from two regional centres in the UK also contributed to focus groups, as did patients from consultant lists in two UK regional centres, and members of Arthritis Care. Chairpersons of six UK MRECs were interviewed. Participants were eligible for the pilot if they were adults (18 years or older) with radiological evidence of osteoarthritis of the knee who might be considered for arthroscopic lavage, and were fit for general anaesthetic (defined by the American Society of Anaesthesiologists grades 1 and 2), and able to give informed consent. Interventions Participants in the pilot study were randomised to arthrosocopic lavage (with or without debridement at the clinical discretion of the surgeon); placebo surgery; or non-operative management with specialist reassessment. Main outcome measures The acceptability and feasibility of mounting a placebo-controlled trial for the evaluation of knee arthroscopic lavage. Results There was broad acceptance across all stakeholder groups of the need to find out more about the effectiveness of arthroscopic lavage. Despite this there was variation in opinion within all the groups about how researchers should approach this and whether or not it would be acceptable to investigate using placebo surgery. Within the health professional groups, there tended to be a split between those who were strongly opposed to the inclusion of a placebo surgery arm and those who were more in favour. For prospective trial participants who had osteoarthritis of the knee, the acceptability of the trial was discussed from a more individual perspective - reflecting on their personal reasons for or against participating. The majority of this group said they would consider taking part. The pilot study showed that, in principle, a placebo-controlled trial could be conducted. It showed that patients were willing to participate in a trial which would involve a placebo-surgical arm and that it was possible to undertake placebo surgery successfully and to blind patients to their allocation - although once patients knew their allocation, some patients allocated to surgery became more concerned about the possibility of undergoing placebo surgery, and withdrew. The experience of the pilot, however, showed that, despite full MREC approval, the study required major discussion and negotiation before local clinical approvals could be obtained. The fact that ethics approval had been granted did not mean that clinicians would automatically accept that the process was ethical. Conclusions The study showed that, in principle, a placebo-controlled trial of arthroscopic lavage could be conducted in the UK, albeit with difficulty. Against the background of falling use of arthroscopic lavage the decision was, therefore, taken not to proceed to full-scale trial for this procedure. The study showed that for some health professionals the use of placebo surgery can never be justified. It highlighted the importance of the surgeon-anaesthetist relationship in this context and how acceptance of the trial design by both parties is essential to successful participation. It also highlighted the importance of informed consent for trial participants and the strength and influence of individuals' ethical perspectives in addition to collective ethics provided by MRECs. Trial registration Current Controlled Trials ISRCTN02328576.