A locally adaptive time-stepping algorithm for\ud petroleum reservoir simulations

An algorithm for locally adapting the step-size for large scale finite volume simulations of multi-phase flow in petroleum reservoirs is suggested which allows for an “all-in-one” implicit calculation of behaviour over a very large time scale. Some numerical results for simple two-phase flow in one space dimension illustrate the promise of the algorithm, which has also been applied to very simple 3D cases. A description of the algorithm is presented here along with early results. Further development of the technique is hoped to facilitate useful scaling properties

Occupational fatalities amongst farm workers in Ireland, 1992 – 2008

working paperBackground: Whilst occupational fatalities amongst farm workers have been studied internationally little research has been published concerning farm fatalities or the demography farm fatalities in Ireland. Aims 1) To establish the incidence of farm fatalities during the 1992 – 2009 period in Ireland, 2) to explore the changing age profile of those experiencing fatal injuries on farms in Ireland. Methods: An official dataset containing the details of every fatal farm accident during the 1992 – 2009 period is used to evaluate changes in the number and age profile of farm fatalities in Ireland. Results: There were 304 deaths on farms during the 1992 – 2009 period in Ireland. The average number of annual fatalities is declining having fallen by 16% from 18 to 16 per year during this time. The fatality rate has however increased from 15 to 22 per 100,000 workers. This has been driven by a reduction in the number of workers employed on farms and, it is hypothesised, rapid ageing of the farm workforce. The demographic profile of those killed on farms changed significantly over the period. There are fewer deaths amongst younger cohorts. Older farmers, those over 55 years of age, now account for the vast majority of all fatal accidents. Conclusion: These findings highlight the changing nature of fatal farm incidents over the 1993 – 2009 period in Ireland. The increasing number of fatalities amongst older farmers suggests that Ireland’s Farm Safety Partnership needs to place greater emphasis of raising awareness amongst older farmers of fatality risks

Revisiting the Cooling Flow Problem in Galaxies, Groups, and Clusters of Galaxies

We present a study of 107 galaxies, groups, and clusters spanning ~3 orders of magnitude in mass, ~5 orders of magnitude in central galaxy star formation rate (SFR), ~4 orders of magnitude in the classical cooling rate (dM/dt) of the intracluster medium (ICM), and ~5 orders of magnitude in the central black hole accretion rate. For each system in this sample, we measure dM/dt using archival Chandra X-ray data and acquire the SFR and systematic uncertainty in the SFR by combining over 330 estimates from dozens of literature sources. With these data, we estimate the efficiency with which the ICM cools and forms stars, finding e_cool = SFR/(dM/dt) = 1.4 +/- 0.4% for systems with dM/dt > 30 Msun/yr. For these systems, we measure a slope in the SFR-dM/dt relation greater than unity, suggesting that the systems with the strongest cool cores are also cooling more efficiently. We propose that this may be related to, on average, higher black hole accretion rates in the strongest cool cores, which could influence the total amount (saturating near the Eddington rate) and dominant mode (mechanical vs radiative) of feedback. For systems with dM/dt < 30 Msun/yr, we find that the SFR and dM/dt are uncorrelated, and show that this is consistent with star formation being fueled at a low (but dominant) level by recycled ISM gas in these systems. We find an intrinsic log-normal scatter in SFR at fixed dM/dt of 0.52 +/- 0.06 dex, suggesting that cooling is tightly self-regulated over very long timescales, but can vary dramatically on short timescales. There is weak evidence that this scatter may be related to the feedback mechanism, with the scatter being minimized (~0.4 dex) in systems for which the mechanical feedback power is within a factor of two of the cooling luminosity.Comment: 16 pages, 10 figures, 6 tables. Submitted to ApJ. Comments welcome

Influence of Sulfur-Containing Diamino Acid Structure on Covalently Crosslinked Copolypeptide Hydrogels.

Biologically occurring non-canonical di-α-amino acids were converted into new di-N-carboxyanhydride (di-NCA) monomers in reasonable yields with high purity. Five different di-NCAs were separately copolymerized with tert-butyl-l-glutamate NCA to obtain covalently crosslinked copolypeptides capable of forming hydrogels with varying crosslinker density. Comparison of hydrogel properties with residue structure revealed that different di-α-amino acids were not equivalent in crosslink formation. Notably, l-cystine was found to produce significantly weaker hydrogels compared to l-homocystine, l-cystathionine, and l-lanthionine, suggesting that l-cystine may be a sub-optimal choice of di-α-amino acid for preparation of copolypeptide networks. The di-α-amino acid crosslinkers also provided different chemical stability, where disulfide crosslinks were readily degraded by reduction, and thioether crosslinks were stable against reduction. This difference in response may provide a means to fine tune the reduction sensitivity of polypeptide biomaterial networks

High-strength alloy with resistance to hydrogen-environment embrittlement

Alloy is precipitation-hardened, high-strength, and low-thermal-expansion materials. It is iron-based and contains nickel and chromium at lower levels than high-strength alloys. It is readily welded and brazed and has good oxidation resistance. Tests indicated there was no reduction of notched or smooth strength

A Study of the Effectiveness of Risk Assessment and Extension Supports for Irish Farmers to Improve Farm Safety and Health Management

Doctoral thesisThe agricultural sector workforce in Ireland and Internationally has a poor occupational safety and health (OSH) record. Given this situation, identifying approaches to improve OSH adoption on farms are urgently required, yet limited research has been conducted on this topic. In Ireland, legislation introduced in 2005 permitted the development of a Code of Practice (COP) in association with a Risk Assessment Document (RAD) for specific sectors to assist owners of small-scale enterprises and the self-employed to manage OSH. Two state agencies, the Health and Safety Authority and Teagasc – Agriculture and Food Development Authority, formed an alliance to undertake a Prevention Initiative to develop the COP and RAD for the agriculture sector and to assist farmers to use these documents to manage farm OSH and to assess the utility of the approach adopted. The Prevention Initiative firstly developed the RAD on a pilot basis and assessed its value in assisting farmers with OSH management in association with provision of short halfday training and follow-up extension. This was followed by circulation of COP documents, including the RAD, to farmers nationally and making available half-day training based on the RAD and associated OSH extension. A mixed-method research approach was implemented to assess the RAD utility and effectiveness while triangulation of data from different sources was undertaken to maximise the knowledge gained. Questionnaires were used among farmer participants (n=1,206) and Teagasc staff (n=54), who facilitated the training, to gain opinions of the RAD and of the training provided. RAD’s were assembled (n=475) and assessed for their completion levels and nature of controls specified for action by farmers. Farm audits were undertaken (n=94) to assess implementation of farm OSH controls in association with RAD use. A nationally representative survey of farmers (n=891) was used to establish levels of COP and RAD usage and farm accident levels. Farmers reported having a positive attitude to farm OSH. They rated the RAD developed on a pilot basis as the most helpful to them in assisting with OSH management when compared with other legal documents developed in Ireland for this purpose. Farmers perceptions of the causes of serious accidents were found to be at variance with objective data and it was concluded that use of the RAD was an effective means of accurate communications. The COP and RAD documents were used to a limited extent among the farming population and it was concluded that greater utility of these documents requires further support through training. Participation in training on RAD completion in the project pilot phase was motivated by farmers’ desire to improve farm OSH and to gain assistance in completing the legally required documents. Among training approaches used, participants rated using accident victim testimonials and visual approaches to show OSH controls most useful while the provision of information on farmers’ health and level of discussion during training as least useful. Most participants were willing to engage in further OSH farm-based extension including participation in further training and attending farm demonstrations. Following RAD completion, most farmers (78%) planned to make OSH changes for which farm resources were mainly available, but just over half (55%) implemented the changes they planned and these were identified as having a prior record of OSH adoption. Farmers identified a limited number of controls in the RAD for action and those who attended training specified a higher level , while controls specified were mainly physical in nature such as machinery and farm facilities improvement. RAD facilitators were satisfied with the content and structure of farmer RAD training and the majority (80%) were also satisfied with the training they received to provide RAD farmer training while those dissatisfied mainly felt that the training provided was too short. Advisors who facilitated RAD training when compared to those not allocated this role, subsequently reported providing higher levels of OSH advice. Farmers’ completion of the RAD with or without training (half-day) was not associated with reduced farm accident levels. Farm accident level was associated with farms where the farmer and spouse had off farm work, which were comparatively larger in scale. Being a Teagasc client or having received agricultural education was not associated with reduced farm accident levels. Overall the study indicates that farmers’ knowledge is not the limiting factor to OSH implementation as use of the RAD and training did not lead to OSH change among prior non-adopters. The study recommends further assessment of extension approaches which can motivate OSH adoption such as use of farmer discussion groups which have been shown to improve farm management and technology adoption

Recent Developments Concerning Constitutional Limitations on State Defamation Laws

Two recent cases, New York Times Co. v. Sullivan A and Garrison v. Louisiana, have over-turned many aspects of state laws regarding the defamation of public officials. The importance of these two cases is due not only to the problems they have solved, but also to the potential confusion which they have created. The primary purpose of this discussion is to point out the practical effect which the decisions will have on state law, both statutory and decisional. This note is concerned primarily with those aspects of the law of defamation dealing specifically with the conditional or qualified privilege to criticize the official acts and qualifications of public officials and candidates. Several questions in this specific area are left unresolved by Sullivan and Garrison

Uyghur Cuisine and Identity: An Historical Overview of a Discreet Diaspora

This work reviews aspects of the disappearing Uyghur foodways since the founding of the People’s Republic of China in 1949 due to migrations, modernization, and now, cultural genocide. Turkic interconnections of culture, trade, and resettlement through the centuries mesh tightly with the Symposium theme of food and movement. The article holds no pretense to exhaustively catalog Uyghur foods or dishes as they can vary greatly within China and even more so throughout the Uyghur communities abroad. The author spent countless time cooking in kitchens and courtyards along the Silk Road in Central Asia and much of the information in the article is based on personal participation and observation. The purpose of this article is to review the historical reasons why the Uyghur diaspora is unusually subdued in their cultural gatherings abroad. It also proposes a global platform for digitally sharing Uyghur foodways and cooking. Fearing for the safety of relatives in Xinjiang or for personal reprisals against them by the government of China, many Uyghurs are resigned to silent support for cultural projects and focus on keeping traditions alive privately only in their homes and within tight communities