128 research outputs found
Heating Augmentation for Short Hypersonic Protuberances
Computational aeroheating analyses of the Space Shuttle Orbiter plug repair models are validated against data collected in the Calspan University of Buffalo Research Center (CUBRC) 48 inch shock tunnel. The comparison shows that the average difference between computed heat transfer results and the data is about 9:5%. Using CFD and Wind Tunnel (WT) data, an empirical correlation for estimating heating augmentation on short hyper- sonic protuberances (k/delta < 0.33) is proposed. This proposed correlation is compared with several computed flight simulation cases and good agreement is achieved. Accordingly, this correlation is proposed for further investigation on other short hypersonic protuberances for estimating heating augmentation
Does accounting treatment of share-based payments impact performance measures for banks?
This paper identifies, evaluates and analyses the resulting impact of mandatory expensing of shareâbased compensation (SBC) under IFRS2/FASB123R on a set of widely used performance measures in the EU and US banking industry. The paper shows that the accounting treatment of SBC schemes, following the mandatory adoption of IFRS2/FAS123R, has a statistically significant negative impact on the selected performance measures over the period 2004â11. The impact also seems to be material, yet modest, for US banks and only for large and highâgrowth EU banks, indicating that earlier public concerns and criticisms of the implementation of IFRS2/FAS123R are largely unsubstantiated. The findings also show that banks continue to use SBC, but there is a reduction, albeit insignificant, in the recognised SBC expense over the period 2009â11. That is, earlier public concerns that firms would curtail employing SBC in their employeesâ compensation schemes to avoid the effect of SBC expense recognition on their financial ratios came to light after the first option lifeâcycle in the postâadoption period was over. The findings also show a marked movement towards using cashâsettledâbased payments, possibly due to their manipulative accounting treatment, a potentially interesting issue for related accounting research and accounting standard setters
Supervisors' Perceptions of the Performance of Cooperative Education Employees Working in Federal Agencies
Through cooperative education programs, many public agencies employ college students part time or intermittently and groom them for future full-time employment The combination of winnowing and nurturing that occurs in these programs is believed to produce higher performing employees This study tests this hypothesis by comparing Federal supervisors' perceptions of the performance of co-op employees with those recruited from other sources Data come from the 1992 Merit Principles Survey, US Merit Systems Protection Board The results indicate that co-op employees perform at high levels, but they do not outperform other employees as a whole Next, we compare the performance ratings of Federal workers from seven other recruitment sources to see if any source is superior Some interesting findings emerge Of course, performance ratings are an incomplete indicator of an employee's value to the organization These ratings merely reflect supervisors' perceptions, and while high performance is important, agencies may wish to promote other goals in their recruitment and retention efforts such as workforce diversityYeshttps://us.sagepub.com/en-us/nam/manuscript-submission-guideline
Brine utilisation for cooling and salt production in wind-driven seawater greenhouses:Design and modelling
Brine disposal is a major challenge facing the desalination industry. Discharged brines pollute the oceans and aquifers. Here is it proposed to reduce the volume of brines by means of evaporative coolers in seawater greenhouses, thus enabling the cultivation of high-value crops and production of sea salt. Unlike in typical greenhouses, only natural wind is used for ventilation, without electric fans. We present a model to predict the water evaporation, salt production, internal temperature and humidity according to ambient conditions. Predictions are presented for three case studies: (a) the Horn of Africa (Berbera) where a seawater desalination plant will be coupled to salt production; (b) Iran (Ahwaz) for management of hypersaline water from the Gotvand dam; (c) Gujarat (Ahmedabad) where natural seawater is fed to the cooling process, enhancing salt production in solar salt works. Water evaporation per face area of evaporator pad is predicted in the range 33 to 83 m3/m2·yr, and salt production up to 5.8 tonnes/m2·yr. Temperature is lowest close to the evaporator pad, increasing downwind, such that the cooling effect mostly dissipates within 15 m of the cooling pad. Depending on location, peak temperatures reduce by 8â16 °C at the hottest time of year
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and lowâmiddle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of âsingle-useâ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for lowâmiddle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both highâ and lowâmiddleâincome countries
Smart systems and simple agents: industry pricing by parallel rules
A standard macroeconomic specification is that the aggregate economy is directed by a single, smart representative agent using optimal decision rules. This paper explores an alternative conjecture--that the dynamic behavior of markets is often better interpreted as the interactions of many heterogeneous, rule-of-thumb agents who are loosely coupled in smart systems--much like the contrast of a single serial processor with global information versus parallel processors with limited communications. The illustration used in this paper is the contrast between a conventional macro model of sluggish adjustments in an aggregate producer price index and a model of delayed industry price adjustments in a distributed production system under costly inter-firm communications.Prices
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