Theory and reality of organic soil fertility - organic matter

This report was presented at the UK Organic Research 2002 Conference. Results are reported suggesting no significant difference between the level of soil organic matter on established organic farms in Southern England and paired conventionally managed farms. We discuss the possible reasons for this and also examine why the literature on this subject is frequently contradictory

Assessing soil structure in organically farmed soils

This report was presented at the UK Organic Research 2002 Conference. Soil structure was assessed in over 90 fields (organic and conventionally farmed) covering mixed, stockless and pasture farming systems. A combination of spade and an objective scoring system based on the degree of aggregation and porosity was able to detect differences between fields. On average, in the fields sampled, topsoil structure was slightly better on the organic farms though, even on the conventional fields, structure was unlikely to limit crop growth

Managing Manure on Organic Farms

The booklet provides information on typical nutrient contents of livestock manures – from organic and ‘conventional’ sources; describes the availability of manure nutrients to the growing crop; outlines best management practices to optimise manure nutrient supply and outlines best management practices to optimise manure nutrient supply. It draws on scientific research undertaken in the 1990, much of it in the UK, and most of it funded by DEFRA

Tort Reform and Accidental Deaths

Theory suggests that tort reform could have either of two impacts on accidents. First, reforms could increase accidents as tortfeasors internalize less of the costs of externalities, and thus, have less incentive to reduce the risk of accidents. Second, tort reforms could decrease accidents as lower expected liability costs result in lower prices, enabling consumers to buy more risk-reducing products such as medicines, safety equipment, and medical services. We test which effect dominates by examining the effect of tort reforms on non-motor vehicle accidental death rates, using panel data techniques. We find that caps on noneconomic damages, caps on punitive damages, a higher evidence standard for punitive damages, product liability reform, and prejudgment interest reform lead to fewer accidental deaths, while reforms to the collateral source rule lead to increased deaths. Overall, the tort reforms in the states between 1981-2000 have led to an estimated 14,222 fewer accidental deaths.

The performance in fire of restrained columns in steel-framed construction.

The University of Sheffield has a non-linear finite element analysis program called VULCAN which has been developed in-house over a number of years and has been thoroughly validated. A parametric study has been conducted using this software, which assesses the influence of such factors as load, geometric imperfection, material properties, temperature profile and axial and rotational restraint on the behaviour, of isolated steel columns in fire. This study is then extended to investigate the behaviour of steel columns as part of a larger multi-storey frame, in which axial restraint to thermal expansion of the heated column is provided by the floors above. A method of modelling these effects in VULCAN using a linear spring element to provide axial restraint has been developed and validated. An experimental partner project has been carried out at the University of Ulster, in which steel columns were furnace-tested with various levels of load, slenderness and axial restraint. These tests have been paralleled with analyses using VULCAN and a good correlation with test results has been shown. The VULCAN program was then used to examine the effects of parameters outside the range of the physical constraints imposed by the test facility. A numerical model, capable of assessing the level of axial restraint imparted on a column by a general multi-storey framed structure has been developed, which has a number of levels of complexity, each giving a higher degree of accuracy. Once the level of restraint for a structure has been assessed, the parametric studies and test data can be applied, and conclusions drawn about the behaviour of the frame. The applicability of different mathematical solution procedures to the analysis of these columns, which exhibit snap-through and snap-back behaviour, has been conducted. The arc-length method has been identified as applicable in such cases and a skeleton version of the procedure introduced into the VULCAN program. The program structure of VULCAN has been improved and the format for data input and output has been developed to allow flexibility. A graphical file-viewer program has also been created. Details of these changes are shown in appendices

A Phase-Locked Loop in High-Temperature Silicon Carbide and General Design Methods for Silicon Carbide Integrated Circuits

Silicon carbide (SiC) has long been considered for integrated circuits (ICs). It offers several advantages, including wider temperature range, larger critical electric field, and greater radiation immunity with respect to Silicon (Si). At the same time, it suffers from challenges in fabrication consistency and lower transconductance which the designer must overcome. One of the recent SiC IC processes developed is the Raytheon High-Temperature Silicon Carbide (HTSiC) complementary MOSFET process. This process is one of the first to offer P channel MOSFETs and, as a result, a greater variety of circuits can be built in it. The behavior of SiC MOSFETs has some important differences with Si MOSFETs. Models such as the Shichman-Hodges, EKV, and Short-channel models have been developed over time to address the important behaviors observed in Si MOSFETs, but none of these captures all of the important effects in SiC. In this work, an improved Shichman-Hodges model that incorporates the body-charge effect, mobility reduction, and a nonlinear channel modulation is developed for SiC CMOS IC devices. The importance of considering these effects is demonstrated with a simple design exercise. This dissertation also describes the design and testing of the first-ever phase-locked loop (PLL) in SiC. This PLL is suitable for use as a general circuit building block such as in a clock recovery circuit. The fabricated circuit operates between 600 kHz and 1.5 MHz, and at temperatures up to 300 ℃. Testing results also show that output jitter and locking are negatively impacted at higher temperatures, and an improved design is proposed and analyzed

The relationship between corporate social responsibility and firm performance: a study of South African listed companies

A research report submitted to the Faculty of Commerce, Law and Management, University of the Witwatersrand, Johannesburg in partial fulfilment of the requirements for the degree in Master of Commerce (50% course work)A growing number of institutional investors that are adopting corporate social responsibility (CSR) philosophy are playing a crucial role in influencing listed companies to adopt and address CSR issues. CSR is defined as “…a concept whereby companies integrate social and environmental concerns in their business operations…” (European Commission, 2010). CSR is now widely accepted as a way of doing business in the contemporary environment. It is evident in companies that are spending large sums of money, time and effort on satisfying various stakeholders’ requirements for responsible behaviour. Despite the growing pressure on companies to become socially responsible, the direct benefits of CSR contribution to firm performance remain questionable. From existing literature the relationship between CSR and firm performance have pointed to mixed results (Gladysek & Chipeta, 2012; Aggarwal, 2013). This study examines the relationship between CSR performance and firm performance using the CSRHub sustainability indexes as proxy for CSR performance. The firm performance measures of firm value (Tobin’s Q) and financial accounting performance (return on assets) were used. Annual data of firms from the Johannesburg Stock Exchange (JSE) from year 2009 to 2012 was analysed using the Multiple Regression Analysis techniques. The study revealed that significant and positive relationship exists between CSR/environmental performance and firm value of listed South African companies. The study concluded that there is no significant relationship between firm performance and the other components of CSR such as community relations, employment relations, and governance. The relatively small sample size of the listed companies, some missing values on the sample data and the shorter time period on the study are the main limitations acknowledged in this report. In the overall, the study provides important insights for understanding the contribution of CSR and its disaggregated components to firm performance

Assessing quality in systematic reviews of the effectiveness of health promotion: areas of consensus and dissension

Systematic reviews have played an increasingly important role in health promotion in recentyears. Yet there are debates about how they should be conducted, particularly about how thequality of evidence should be assessed. The aim of this research was to assess currentapproaches to, and general views on, the use of quality assessment in systematic reviews ofeffectiveness in health promotion, and to identify areas of consensus and dissension around thechoice of techniques, methods and criteria employed.There were two stages of data collection. The first was a structured mapping of a randomsample of 30 systematic reviews of the effectiveness of health promotion to identify and explaintrends and themes in methods and approaches to quality assessment. During the second stagesemi-structured interviews were conducted with a purposive sample of 17 systematic reviewerswho had conducted at least one review of a health promotion topic, to investigate some of thesetrends and approaches in greater detail.The mapping found that the majority of systematic reviews had assessed the quality of theincluded studies, to varying degrees. However, procedures were not always explicitly reportedor consistent. There was some degree of consensus over criteria, with experimental evaluationmethods commonly favoured. Most frequently used quality assessment criteria includedparticipant attrition, the validity and reliability of data collection and analysis methods, andadequacy of sample sizes. External validity was commonly assessed, primarily in terms ofgeneralisability and replicability, but less so in terms of intervention quality.The interviews revealed some of the barriers to effective systematic reviewing, including: lackof time and resources, complexity of some health promotion interventions, inclusion ofobservational evaluation designs, and poor reporting of primary studies. Systematic reviewingwas commonly done in small teams, mostly comprising academics, sometimes withpractitioners. Interviewees learned systematic review skills through a combination of training,support from colleagues and mentors, literature and a strong emphasis on hands-on practicallearning. Subjective judgement was often required, contra to the popular belief that systematicreviews are wholly objective.The overall conclusions of this study are that systematic reviewing in health promotion is oftenchallenging due the complexity of interventions and evaluation designs. This places additionaldemands on reviewers in terms of knowledge and skills required, often exacerbated by finitetime scales and limited funding. Initiatives are in place to foster shared ways of working,although the extent to which complete consensus is achievable in a multi- disciplinary area suchas health promotion is questionable

The New Politics of Women, Peace and Security

The LSE Centre for Women, Peace and Security Working Paper Series is an outlet for articles, position papers and policy briefs. It showcases work in progress by academics and researchers from any discipline and sector in the field of women, peace and security research and practice. On publication of the first two papers, lead editors Paul Kirby and Laura J. Shepherd introduce the context and aims of the series