Effective Functional Form of Regge Trajectories

We present theoretical arguments and strong phenomenological evidence that hadronic Regge trajectories are essentially nonlinear and can be well approximated, for phenomenological purposes, by a specific square-root form.Comment: 29 pages, LaTeX. Published versio

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 low–middle-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 ‘single-use’ 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 low–middle-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 high– and low–middle–income countries

Experimental investigation of a multicylinder unmodified diesel engine performance, emission, and heat loss characteristics using different biodiesel blends: Rollout of B10 in Malaysia

This paper deals with the performance and emission analysis of a multicylinder diesel engine using biodiesel along with an in-depth analysis of the engine heat losses in different subsystems followed by the energy balance of all the energy flows from the engine. Energy balance analysis allows the designer to appraise the internal energy variations of a thermodynamic system as a function of ‘‘energy flows’’ across the control volume as work or heat and also the enthalpies associated with the energy flows which are passing through these boundaries. Palm and coconut are the two most potential biodiesel feed stocks in this part of the world. The investigation was conducted in a four-cylinder diesel engine fuelled with 10% and 20% blends of palm and coconut biodiesels and compared with B5 at full load condition and in the speed range of 1000 to 4000 RPM. Among the all tested blends, palm blends seemed more promising in terms of engine performance, emission, and heat losses. The influence of heat losses on engine performance and emission has been discussed thoroughly in this paper

Impact of oxygenated additives to palm and jatropha biodiesel blends in the context of performance and emissions characteristics of a light-duty diesel engine

In recent years, palm and jatropha biodiesels have been considered as potential renewable energy sources in Malaysia. Therefore, this experimental investigation was conducted to improve the blend of these two biodiesels (20% biodiesel blend, named P20 and J20, respectively) with the help of oxygenated additives. The comparative improvement of P20 and J20 blends with ethanol, n-butanol, or diethyl ether as additives was evaluated in terms of performance and emissions characteristics of a four-stroke single cylinder diesel engine. The final blend consisted of 80% diesel, 15% biodiesel, and 5% additive. Tests were conducted at different speeds (1200-2400 rpm) at constant full load conditions. Use of additives significantly improved brake power and brake thermal efficiency (BTE). Compared with P20 blend, the use of diethyl ether as additive increased brake power and BTE by about 4.10% and 4.4%, respectively, at 2200 rpm. A similar improvement was observed for J20. The other two additives also improved performance. Although HC emission increased slightly, all blends with additives reduced more NO_x and CO emissions than P20 and J20 almost throughout the entire engine test. The use of ethanol as additive reduced CO emission by up to 40%, while the use of diethyl ether as additive reduced NO_x emissions by up to 13%. The additives' oxygen content, volatility, and latent evaporation heat controlled the emissions characteristics of the blends. An analysis of the combustion chamber pressure, temperature and heat release rate of the modified blends revealed interesting features of combustion mechanism, which are indicative of the performance and emissions characteristics. This experiment reveals the potential improvement of palm and jatropha biodiesel blends with the addition of three promising additives

Engine combustion, performance and emission characteristics of gas to liquid (GTL) fuels and its blends with diesel and bio-diesel

Crude oil price hikes, energy security concerns and environmental drivers have turned the focus to alternative fuels. Gas to liquid (GTL) diesel is regarded as a promising alternative diesel fuel, considering the adeptness to use directly as a diesel fuel or in blends with petroleum-derived diesel or bio-diesel. GTL fuel derived from Fischer-Tropsch synthesis is of distinctly different characteristics than fossil diesel fuel due to its paraffinic nature, virtually zero sulfur, low aromatic contents and very high cetane number. GTL fuel is referred to as a “clean fuel” for its inherent ability to reduce engine exhaust emission even with blends of diesel and bio-diesel. \ud \ud This paper illustrates feasibility of GTL fuel in context of comparative fuel properties with conventional diesel and bio-diesels. This review also describes the technical attributes of GTL and its blends with diesel and bio-diesel focusing their impact on engine performance and emission characteristics on the basis of the previous research works. It can introduce an efficacious guideline to devise several blends of alternative fuels, further the development of engine performance and constrain exhaust emission to cope with the relentless efforts to manufacture efficient and environment friendly powertrains

Emission and performance improvement analysis of biodiesel-diesel blends with additives

Abstract This experimental investigation evaluates the comparative improvement of palm biodiesel-diesel blend (20 palm biodiesel-80 diesel) with the help of ethanol, n-butanol and diethyl ether as additives regarding emission and performance characteristics. The improved blends consisted 80 diesel, 15 palm biodiesel and 5 additive. Use of additives prominently improved brake power, decreased {BSFC} (brake specific fuel consumption) and increased {BTE} (brake thermal efficiency). Diethyl ether showed highest 6.25 increment of brake power, 3.28 decrement of {BSFC} and about 4 increment of {BTE} than 20 palm biodiesel-diesel blend when used as additive. Other two additives also showed interesting improvement regarding performance. All the blends with additives showed decreased {NO} and {CO} emission but {HC} emission showeda slight increment. However, this experiment reveals comparative suitability of these three additives on improving biodiesel-diesel blend

Coordination: Reo, nets, and logic

This article considers the coordination language Reo, a Petri net variant called zero-safe nets, and intuitionistic temporal linear logic (ITLL). The first part examines the semantics of the coordination language Reo in relation to zero-safe nets. Although the external presentations of the two models are quite different, the difference in underlying semantics is rather small. In fact, Reo connectors can be compositionally encoded into zero-safe nets. This means that the tools and techniques developed for Petri nets over the last 30 years, such as various extensions to the zero-safe nets model, such reconfigurable and dynamic nets, can be adapted to the Reo setting. The second part re-examines the idea of using linear logic as a basis for coordination languages. Specifically, we argue that intuitionistic temporal linear logic (ITLL) can encode the semantics of Reo and zero-safe nets, by encoding their notion of transaction. Moreover, by adapting the encoding and exploring the additional connectives of ITLL, it can form the basis of an expressive coordination language which goes beyond these models, by introducing means for explicitly reasoning about choices made by the environment and by providing more fine-grained control over the timing of interaction.status: publishe