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Ore preparation facilities are complex facilities and various wastes in the form of solid, liquid and gas can come out of these facilities. Generally, various chemicals can be found in the wastes that pass through the aqueous processes. According to the type of enrichment method used in the process, the contents of the wastes also change. While some wastes consist entirely of harmless natural stones, some wastes may contain harmful chemicals such as cyanide, sulfur, fatty acid, alcohol and caustic. In such cases, the treatment of waste also differs. A different waste disposal method should be followed for each mine type. In this study, the wastes from the ore preparation facilities, which are also under control with legal sanctions, and the management of wastes are discussed. [ABSTRACT FROM AUTHOR]

Dynamic nuclear polarization, or DNP, refers to the increase of the polarization of nuclear spins in condensed matter, liquid or solid, coupled with electronic spins at low relative concentration, by inducing radio or microwave transitions at frequencies close to the electronic resonance frequency in the external magnetic field. Another described method relies on indirect optical pumping methods at temperatures close to room temperature for the nuclear polarization of rare gases. The various mechanisms of DNP are described in physical terms. This is followed by a succinct description of its main applications in various domains of physics, in chemistry and in medicine. [ABSTRACT FROM AUTHOR]

The increased number of modern livestock farming increase pollutant gas and particulate matter emissions and expanding of residential area against rural area cause to be more sensitive to these gas and particulate matter emissions from animal operations. In this study, pollutant gas dispersions from three dairy cattle barns operated in Bursa region were modelled using hourly outdoor environmental and topographic conditions. To develop dispersion models and describe dispersion problem as a quantity, pollutant gas emissions from dairy cattle operations and CALPUFF VIEW 5.8 modelling software were used. It was determined that estimated pollutant gas concentrations in five receptor points (A-E) in surrounding environment were significant levels. Furthermore pollutant gas emissions from dairy cattle barns can reach a remarkable values in an area with 2000 m diameter in surrounding environment. [ABSTRACT FROM AUTHOR]

The increased number of modern livestock farming increase pollutant gas and particulate matter emissions and expanding of residential area against rural area cause to be more sensitive to these gas and particulate matter emissions from animal operations. In this study, pollutant gas dispersions from three dairy cattle barns operated in Bursa region were modelled using hourly outdoor environmental and topographic conditions. To develop dispersion models and describe dispersion problem as a quantity, pollutant gas emissions from dairy cattle operations and CALPUFF VIEW 5.8 modelling software were used. It was determined that estimated pollutant gas concentrations in five receptor points (A-E) in surrounding environment were significant levels. Furthermore pollutant gas emissions from dairy cattle barns can reach a remarkable values in an area with 2000 m diameter in surrounding environment. [ABSTRACT FROM AUTHOR]

The increased number of modern livestock farming increase pollutant gas and particulate matter emissions and expanding of residential area against rural area cause to be more sensitive to these gas and particulate matter emissions from animal operations. In this study, pollutant gas dispersions from three dairy cattle barns operated in Bursa region were modelled using hourly outdoor environmental and topographic conditions. To develop dispersion models and describe dispersion problem as a quantity, pollutant gas emissions from dairy cattle operations and CALPUFF VIEW 5.8 modelling software were used. It was determined that estimated pollutant gas concentrations in five receptor points (A-E) in surrounding environment were significant levels. Furthermore pollutant gas emissions from dairy cattle barns can reach a remarkable values in an area with 2000 m diameter in surrounding environment. [ABSTRACT FROM AUTHOR]

Intact human skin surface is essential for protection against infection, preservation of body fluid homeostasis and thermoregulation. Burn injury compromises the skin barrier and enables bacterial infection, hence delaying burn wound healing. This study aimed to determine the microbial profile of burn wounds, and resistance patterns of microbes with respect to the source of the injured patient's wound. Fifty wound swab samples were collected from fifty burn patients at the Korle-Bu Teaching Hospital, Accra (KBTH). Sterile swabs moistened with sterile saline were used to swab burn wounds. The swabs were plated on blood agar and MacConkey agar for 24 hrs at 37°C. Biochemical tests were carried out on the representative isolate on each plate, and antibacterial sensitivity pattern was determined using the Kirby-Bauer disc diffusion method. The study revealed that the main source of burns was gas flames (66%) and scalds (28%). Out of the 50 samples analysed, 86% were culture positive and 14% were culture negative for bacteria. The predominant organisms isolated were Pseudomonas sp. (30.2%) and Acinetobacter sp. (20.9%). Proteus mirabillis (2.3%) and Staphylococcus aureus (2.3%) were the least frequently isolated bacteria. Although Pseudomonas sp. showed varying resistance levels to gentamicin, cotrimoxazole and ciprofloxacin, all the Acinetobacter sp. were resistant to most of the tested antibiotics used. Resistant gram negative bacteria are the most common isolates associated with burn wounds in Accra, Ghana. Hence a careful selection of antibiotics to control the wound infection is required for proper management of burn wounds in order to help reduce morbidity and mortality. [ABSTRACT FROM AUTHOR]

Introduction: Fractional laser technology is a new emerging technology to improve scars, fine lines, dyspigmentation, striae and wrinkles. The technique is easy, safe to use and has been used effectively for several clinical and cosmetic indications in every skin type. Devices: Different fractional laser machines, with different wavelengths, both ablative and non-ablative, are now available in Turkey. A detailed understanding of the device and wavelenght being used is recommended. Indications: Common indications include resurfacing for acne, chickenpox and surgical scars, periorbital and perioral wrinkles, photoageing changes, facial dyschromias. The use of fractional lasers in stretch marks, melasma and other pigmentary conditions, dermatological conditions such as granuloma annulare has been reported. Laser parameters: There are different machines based on different technologies available. Choice parameters depend on the type of machine, location and type of lesion, and skin color. Physician needs to be familiar with these requirements before using the machine. Anesthesia: Fractional laser treatment can be carried out under topical anesthesia with mixture of lidocaine and prilocaine. Some machines can be used without any anesthesia or only with topical cooling or cryospray. But for maximal patient comfort, a topical anesthetic prior to the procedure is recommended. Postoperative care: Proper postoperative care is important in avoiding complications. Post-treatment edema and redness settle in a few hours to a few days. A sunscreen is mandatory, and emollients may be prescribed for the dryness and peeling that could occur. [ABSTRACT FROM AUTHOR]

Purpose: Evaluation of the clinical characteristics and their effect on prognosis of glaucoma cases which developed following vitrectomy or became uncontrollable by medical therapy and needed surgical procedure is aimed. Materials and Methods: Initial and last visual acuity (VA), intraocular pressure (IOP), additional medical treatment or surgical procedures and latest clinical findings were evaluated in the patients. Results: Eight eyes of 8 patients were involved in this study. Mean patient age was 49.5±17.9 years. Primary diagnosis included retinal detachment with retinal hole/giant retinal tear, vitreous hemorrhage due to diabetic retinopathy and epiretinal membrane formation. Intraocular tamponades used after vitrectomy included silicone oil in 5 eyes, SF6 in 2 eyes and C3F8 in one eye. Glaucoma surgeries included non-penetrating deep sclerectomy(NPDS) in 3 eyes, trabeculectomy in 4 eyes (with 5-fluorouracil (5FU) in 3 eyes), trabeculectomy with 5FU and phacoemulsification+intraocular lens implantation in one eye and trabeculectomy in one eye following NPDS. Mean preoperative IOP was 29.83±7.80 mmHg in 6 eyes which underwent trabeculectomy. Mean IOP was 22.5±4.80 mmHg (n=6) at postoperative 1st month and 20.6±5.41 mmHg at last visit. Mean follow-up time was 13±8.6 months. Seven out of 8 patients needed antiglaucomatous medical therapy. Median initial VA was seeing hand movements and last median VA was 15/100. Anatomical success was achieved in all but one. Conclusion: In this case series, glaucoma surgery was found ineffective, and early postoperative antiglaucomatous treatment was needed. Regular and continuous follow-up of these patients is needed. [ABSTRACT FROM AUTHOR]

The Council of the Gulf Cooperation forms a unique model of collaboration across the Middle East region. This integration grouping was established in 1981 and became involved in a long evolutionary process that resulted in the commitment of member states to current and deep integration, at least at the economic level. Gulf regional security has been troubled since the formation of the Gulf Cooperation Council and its is being questioned or threatened on various occasions. At the same time, international position and importance of the Gulf region as a reservoir of energy resources increased level of vitality for global stability and development. Gulf Cooperation Council are leading the production and export of oil and gas in international markets, so their security and stability is important for the global economy. In the perspective of time, all they have created security and military narrow borders with the United States or expand existing ones, which shaped their behavior and international integration processes affected. There are still significant challenges ahead of the Gulf Cooperation Council, but in recent years we can see decent growth in an effort to implement the goals settled. The main purpose is to analyze the social - economic position of the states of the Gulf Cooperation Council, the main reason to point integration processes and show the evolution of the organization has passed, and to describe the main obstacles and opportunities ahead. [ABSTRACT FROM AUTHOR]

Abstract: The specific isobaric heat capacity was measured for R 32 (difluoromethane) in the gas phase. Twenty-one measurements for R 32 were obtained at temperatures from 282 to 319 K and at pressures from 1.0 to 2.4 MPa, which are very close to the saturation curve. The expanded uncertainty (k = 2) of the temperature measurements is estimated to be less than 23 mK, and that of the pressure measurements is less than 15 kPa. The expanded uncertainty for c p is estimated to range from 15 to 47 J kg−1 K−1. The measurements were compared with available equations of state. Based on the measurements, heat capacity curves of the ideal gas and saturated vapor of R 32 were specified. These data will be very useful for improving available models, especially for correcting behavior in the gas phase, so as to represent reliable thermodynamic properties of R 32 and refrigerant mixtures with R32 that are used for refrigeration and air conditioning systems. [Copyright &y& Elsevier]

Abstract: The transport properties and the gas cooling heat transfer coefficients of CO2–oil mixtures were investigated under gas cooling conditions for a CO2 refrigeration system. The viscosity and thermal conductivity of the CO2–oil mixture were predicted using the TRAPP model under the high pressure condition of around 10 MPa. Depending on the oil concentration, two different models: the homogenous model and separate model, were utilized to estimate the gas cooling heat transfer coefficient. Significant variations of the thermophysical properties of pure CO2 with oil concentration heavily influenced the gas cooling characteristics of the CO2–oil mixture. The homogenous model for low oil concentrations (i.e. 1.0 wt.%) and the separate model for relatively high oil concentrations (i.e. 5.0 wt.%) predictions matched the previous experimental data with mean deviations of ±13.2% and ±33.4%, respectively. [Copyright &y& Elsevier]

Abstract: The specific isobaric heat capacity (cp ) was measured for R32 (difluoromethane) in the gas phase. Thirty-two measurements for R32 were obtained at temperatures from 274 to 353 K and at pressures from 0.65 to 2.4 MPa. Some of them are close to the saturation curve. The expanded uncertainty (k = 2) of the temperature measurements is estimated to be less than 26 mK, and that of the pressure measurements is less than 23 kPa. The expanded uncertainty for cp is estimated to range from 13 to 27 J kg−1 K−1. The experimental data were compared with available equations of state. These data will be essential for improving available models so as to represent more reliable thermodynamic properties of R32 and refrigerant mixtures with R32 that are used for refrigeration and air conditioning systems. [Copyright &y& Elsevier]

Abstract: The 3D seismic exploration, actively deployed in recent years on much of the West Siberian Platform – one of the world''s largest oil and gas bearing basins – has brought out extensive development of a system of strike-slip faults within the basement. The fault system causes local structural and fluid flow anomalies within the Jurassic-Cretaceous sedimentary section, which is known to accommodate a multitude of large oil and gas deposits. This article will show the distribution geography and the scale of the basement strike-slip tectonics, and explain why this phenomenon, so clearly highlighted by 3D seismic, was not discovered earlier. The article will also consider how strike-slip faults are detected in the sedimentary cover and how they impact the characteristics of oil and gas fields located in their vicinity. [Copyright &y& Elsevier]

Abstract: This paper focused on the determining of gas types in counter flow type vortex tubes. In the present study, four different gas types including air, oxygen, nitrogen, and argon in the vortex tube with different inlet pressures and nozzle numbers have been used. The main aims of this paper are to investigate the correlations between gas types and input parameters comprising nozzle numbers, inlet pressures, inlet mass flow rate, temperature of cold outlet, temperature of hot outlet, and cold mass fraction and to select the most important attributes using correlation based attribute reduction and pairwise fisher score attribute reduction (PFSAR). After attribute reduction methods applied to dataset, k-nearest neighbor and C4.5 decision tree classifiers have been used to determine the gas type in the RHVT. The results have demonstrated that the PFSAR is a robust and efficient method in the reduction of attributes belonging to vortex tube. [Copyright &y& Elsevier]

Abstract: The specific isobaric heat capacity (cp ) was measured for R125 (pentafluoroethane) in the gas phase by using a flow calorimeter. Twelve measurements for R125 were obtained at temperatures from 313 to 333K and at pressures from 0.8 to 2.4MPa. Some of them are close to the saturation curve. The expanded uncertainty (k =2) of the temperature measurements is estimated to be less than 23mK, and that of the pressure measurements is less than 14kPa. The expanded uncertainty for cp is estimated to range from 12 to 22Jkg−1 K−1. Also, the experimental data were compared with available equations of state. From the results, it became clear that these data will be essential to improve available models so as to represent more reliable thermodynamic properties of R125 and refrigerant mixtures with R125 that are used for refrigeration and air conditioning systems. [ABSTRACT FROM AUTHOR]

In challenging times for European energy security, the European Union (EU) is seeking to extend its energy policy powers. At the same time, with its message that the High North represents diversification away from less stable energy regions, Norway is trying to get attention in Brussels. This article inquires into the place of Norway and its Arctic oil and gas in the processes of developing an Energy Policy for Europe and the Northern Dimension Initiative. Central questions to be addressed are whether Norwegian Arctic areas are emerging as a new energy region to rely on for diversified oil and gas imports for the European Union, and whether Norway, as a small state but a major energy exporter with a considerable part of the Barents Sea shelf, is able to take advantage of this position in its diplomatic relations with Brussels. The study shows that Norway has managed to use its Arctic oil and gas to create awareness of the Norwegian High North in Brussels between 2006 and 2008, but these efforts have not resulted in more active political interest on the part of the EU. A combination of institutional confusion in the EU, lack of coherence and clarity in the Norwegian High North initiative, and Norway's established reputation as an energy supplier place important constraints on the prospects for more concrete political attention from the EU, and thus on Norway's ability to take advantage of its High North oil and gas in a foreign policy context. [ABSTRACT FROM AUTHOR]

Abdominal compartment syndrome is a serious abdominal condition with significant percentage of morbidity and mortality and can result from various reasons. Here we present a rare case of intra-abdominal hypertension where a 26 years male patient developed grade IV intra abdominal hypertension following deliberate entry of air due to opening of balloon inflator cylinder through his anus by his peer group while poking fun. However we also find that intervention at an appropriate time may prevent the complication of abdominal compartment syndrome in spite of substantial rise of intra abdominal pressure at the time of presentation. [ABSTRACT FROM AUTHOR]

Abstract: Gas-storage ice is the ice that contains various functional gas pores, and can be produced by freezing water in which a desired gas is dissolved. In this conventional method, however, the gas content in the ice is limited by the gas solubility in water. To overcome this limitation, we developed a method to produce gas-storage ice from water in which microbubbles of a desired gas are dispersed, and then obtained images of the structural features of pores formed in the ice prepared using this microbubble method. The images clarified the interaction between a microbubble arriving at an ice–water interface and an existing pore already formed in the ice. The air content in ice prepared using the microbubble method was higher than that prepared using the conventional method, and was about three times higher than the solubility of air in water. [Copyright &y& Elsevier]

Abstract: An experimental test program was conducted on a novel Ericsson cycle heat pump. The concept uses liquid flooding of the compressor and expander to approach isothermal compression and expansion processes. Open drive automotive scrolls were used in the experimental system. Numerous experiments were run at various conditions using nitrogen as the refrigerant and alkyl-benzene oil as the flooding liquid. Cooling capacities of over 670W and volumetric cooling capacities of more than 110kJ/m3 were measured. Second law efficiencies of approximately 3% were achieved. Similar to other gas cycles, the cycle performance is very sensitive to the adiabatic efficiencies of the rotating equipment and the performance of the off-the-shelf equipment was not sufficient to achieve high cycle efficiency. In addition, large pressure drops occurred in the system due to the instrumentation used and the long and arduous flow paths. The scroll compressor and expander were found to perform well considering that they were not designed for the operating conditions encountered. [Copyright &y& Elsevier]

Abstract: The flash gas generation at the expansion device inlet in multi-air-conditioners causes rapid reduction of refrigerant mass flow rate and irregular distribution of refrigerant into multi-indoor units. The objective of this study is to evaluate the influence of the flash gas generation on the dynamic characteristics of a refrigeration system. The dynamic characteristics of a refrigeration system with an electronic expansion valve (EEV) were measured with time at various levels of flash gas generation, which were expressed as flash gas ratio. In addition, the averaged operating parameters and system COP were investigated with the variation of flash gas ratio. As the EEV inlet condition changed from the subcooled to the two-phase state, the refrigerant flow rate decreased rapidly due to the flash gas generation at the EEV inlet. At two-phase inlet conditions, the system operating parameters, such as mass flow rate, suction and discharge pressures, fluctuated periodically with time. As the flash gas ratio increased, the average COP decreased and the discharge temperature increased, degrading the system performance and reliability more severely. [Copyright &y& Elsevier]

Résumé: La présence d’air dans le tissu sous-cutané d’un membre représente une observation redoutable étant donné les conséquences dévastatrices potentielles à la fois pour le membre et pour la vie du patient. Les auteurs présentent ici le cas rare d’un jeune patient ayant un emphysème sous-cutané situé au niveau de la cuisse provoqué par le patient lui-même et qui a abouti à une prise en charge agressive ayant consisté en une antibiothérapie IV, une oxygénothérapie hyperbare et un parage chirurgical. Une corrélation des divers résultats : les antécédents, l’examen physique, l’imagerie et les examens biologiques est primordiale afin d’éviter tout traitement radical inutile. En l’absence d’une cause apparente, il faut toujours penser à une pathologie factice. [Copyright &y& Elsevier]

Abstract: A new model for hermetic reciprocating compressors is presented. This model is able to predict compressor efficiency and volumetric efficiency in terms of a certain number of parameters (10) representing the main sources of losses inside the compressor. The model provides users with helpful information about the way in which the compressor is designed and working. A statistical fitting procedure based on the Monte Carlo method was developed for its adjustment. The model can predict compressor performance at most points with a maximum deviation of 3%. A possible gas condensation on cold spots inside the cylinder during the last part of the compression stroke was also evaluated. [Copyright &y& Elsevier]

Abstract: This paper presents a novel concept to integrate a heat pump system and a power system which form a hybrid-power gas engine-driven heat pump (HPGHP) system. The power system of the HPGHP system includes an engine, a motor, a set of battery packs, a continuous variable transmission device and a power-control module. The engine in the power system is capable of operating constantly with high thermal efficiency and low emissions during the four different operating modes: for operating mode A, the ICE powers directly to match the compressor''s demand load by throttling the natural-gas flow or adjusting the speed of the ICE, correspondingly the battery packs are disengaged and the ICE operates alone; for operating mode B, the ICE operates in the unique condition with the lowest fuel consumption ratio, meanwhile, the battery packs discharge to provide the supplementary power by the power-control module; for operating mode C, the ICE operates in the unique condition with the lowest fuel consumption ratio, and the redundant power provided by the ICE is converted by the motor to charge the battery packs, here, the motor is used as a generator; for operating mode D, the ICE is disengaged and the battery pack is used alone. Simulation results of the power system showed that for a conventional gas engine-driven heat pump (GHP) system the maximum and minimum thermal efficiencies of the power system are 33% and 22%, respectively; compared with the conventional GHP system, the power system in the novel HPGHP system has superior performance with the maximum and minimum thermal efficiencies of 37% and 27%, respectively. [Copyright &y& Elsevier]

Abstract: A dummy port plays an important role in the porting process and the improvement of the performance of a scroll compressor. This paper documents an investigation on the working mechanism of the dummy port in a scroll compressor. To characterize the dummy port effects on the different parts of the scroll compressor, two scroll compressors, one with and the other without a dummy port, are studied comparatively. The flow through the dummy port is examined in the background of an integrated compressor working process. The assembly of the compressor under investigation includes the upper bearing housing, scrolls, check valve, and discharge plenum. The Navier–Stokes equations with a k–ɛ turbulence model are solved at the standard operating conditions of a scroll compressor. Refrigerant-22 is used as the working fluid. The thermodynamic and transport properties of the refrigerant gas are modeled by the Martin–Hou equation of state and power laws, respectively. Global flow physics is investigated first to lay a foundation to understand the working mechanisms that control the porting process before averaging techniques are applied. The behavior of the gas pockets in the porting process is characterized in both geometric and dynamic nature. The time-dependent variation of volume, mass, energy, and volume-averaged field quantities inside the gas pockets are studied throughout the porting process. The impact of the dummy port on the compressor performance is defined. [Copyright &y& Elsevier]

Abstract: We considered mass and heat transfer during nonisothermal absorption of a gas by a falling droplet with internal circulation. Gas phase is assumed to be free of inert admixtures and mass transfer is liquid phase controlled. Mass flux is directed from a gaseous phase to a droplet, and the interfacial shear stress causes a fluid flow inside the droplet. Droplet deformation under the influence of interface shear stress is neglected. Absorbate accumulation and temperature increase in the bulk of liquid phase are taken into account. The problem is solved in the approximations of a thin concentration and temperature boundary layers in the liquid phase. The thermodynamic parameters of the system are assumed constant. The system of transient partial parabolic differential equations of convective diffusion and energy balance with time-dependent boundary conditions is solved by combining the similarity transformation method with Duhamel''s theorem, and the solution is obtained in a form of Volterra integral equation of the second kind which is solved numerically. Theoretical results are compared with available experimental data for water vapor absorption by falling droplets of aqueous solution of LiBr. [Copyright &y& Elsevier]

Abstract: The present study experimentally investigated the two-phase flow split of refrigerants at a T-junction. As geometric parameters, the direction of the inlet or branch tube and the tube diameter ratio of branch to inlet tube were chosen. As inlet flow parameters, the inlet mass flux and quality were varied from 100 to 700kgm−2 s−1 and from 0.1 to 0.9, respectively, for the condition of distribution header of a multi-pass evaporator in the general refrigeration system. All experiments were performed for R-22, R-134a, and R-410A. The measured data were compared with the values predicted by the models developed for air–water or steam–water mixture in the literature. We propose a modified model for application to the reduced T-junction and vertical orientation of tubes. Among the geometric parameters, the branch tube direction showed the largest sensitivity to the mass flow rate ratio for the gas phase, while the inlet quality showed the largest sensitivity to the mass flow rate ratio among the inlet flow parameters. [Copyright &y& Elsevier]

Abstract: This paper summarizes analyses of refrigerant options for chillers. It presents tabulated global warming potentials and other environmental data for candidate refrigerants. The paper discusses briefly the historic progression in refrigerant release reductions and presents analyses to compare the efficiencies of historic and current refrigerant options. The 28 refrigerants addressed include chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), hydrofluorocarbon (HFC), hydrocarbon (HC), and inorganic (such as ammonia) fluids. The paper discusses the relative importance of the refrigerant-related and energy-related components of chiller emissions. [Copyright &y& Elsevier]

Abstract: The modelling of consumption and emissions of ozone depleting chemicals and greenhouse gases has been a challenge for the communities of both the Montreal and Kyoto Protocols. One of the particular challenges has been the representative modelling of consumption in sectors with substantial delays in emission and the resulting accumulation of ‘banks’. Several experts, including the authors of this paper, have been active in building databases of sources over the last 5 years and have continued to refine estimates as new information has come to light. The decision of the Inter-Governmental Panel on Climate Change to commission a Special Report on factors influencing the interface between the two Protocols has acted as a stimulus to draw conclusions from the current state of knowledge. This paper is the product of this initiative as it relates to two key sectors of delayed emission: refrigeration equipment and insulating foams. As the title indicates, the paper documents the development of consumption, banks and emissions for both sectors and uses these to develop estimates of anticipated atmospheric concentration. These estimates are then compared with measured atmospheric concentrations in order to evaluate the appropriateness of the modelling approaches used and to identify areas where discrepancies remain. Efforts have been made to explain these discrepancies wherever possible, but it is recognised that the process remains one of continuous refinement. The major findings of the work are that emissions of refrigerants and foam blowing agents will continue well beyond the scope of the current study (1990–2015), with banks of 2.5 and 3 million tonnes, respectively, remaining at 2015. However, the composition of each bank is very different because of the more rapid turnover in the refrigeration sector led by higher emission rates and shorter product lifetimes. This means that the CFC component of some blowing agent banks may provide a significant target for reducing climate change impact of future emissions where technical and economic criteria are met. For the refrigeration sector better containment, recovery at end of life, re-use or destruction, but also change of refrigerant are the key options. There is clear evidence that the atmospheric concentration predictions for those fluorinated compounds predominantly used as blowing agents are less certain. This is partially because of the high dependence of the prediction on the emission functions assumed during the long use phase. A small variance can have a significant impact on the outcome. There are also continuing uncertainties about end-of-life scenarios for major market sectors such as the US domestic refrigerator sector. These areas are the focus of continuing study. [Copyright &y& Elsevier]

Abstract: The article gives an overview of emission models based on global sales data using a top down analysis. It also elaborates on emission models based on demand in specific sectors (a bottom-up approach) including recovery for both refrigeration and foams; it presents how these bottom-up methods are applied. It summarises the measurements of concentrations of relevant gases in the atmosphere and describes how atmospheric concentrations can be calculated from emission data. Consequently it provides a basis for the practical determination of emission data, as well as the comparison of these data with atmospheric concentrations, and is also a summary description of the tools which can be used for the determination of emission data. [Copyright &y& Elsevier]

A numerical code was developed for an accurate fully three-dimensional simulation of crossflow compact heat exchangers using finned flat tubes with internal microchannels; such components are often employed as gas coolers in transcritical refrigerating machines CO2 operated. The equations describing the system were discretised by means of a finite-volume and finite-element hybrid technique for strictly adhering to the real heat transfer process regarding the finned surfaces. The numerical code uses recent correlations by different authors for predicting the heat transfer coefficients both refrigerant side and air side. The results of simulations are verified against experimental data reported in the open literature.The aim of this work is to investigate the effects of thermal conduction inside metal on the overall performance of the considered gas coolers; high-resolution meshes for the discretisation of separating wall and fins makes it possible to avoid much of the approximations typical of the traditional approaches. In particular the efficiency of finned surfaces, the real distribution of thermal fluxes between the two fin roots and the effects of thermal conduction along the walls of microchannel flat tubes are extensively discussed.The numerical simulations confirm that the traditional approach for describing fins, which assumes them as adiabatic at the middle section in order to decouple the equations accounting for the effect of different temperatures at the fin roots, can be considered acceptable in a wide range of applications. In a similar way, the conduction on fins along the direction of the air velocity and the longitudinal conduction on tubes produce a negligible effect on the performance of the considered class of heat exchangers. [Copyright &y& Elsevier]

This paper presents the experimental data for the heat transfer and pressure drop characteristics obtained during the gas cooling process of carbon dioxide in a horizontal tube. The tubes in which carbon dioxide flows are made of copper with an inner diameter of 7.73 mm. Experiments were conducted for various mass fluxes and inlet pressures of carbon dioxide. Mass fluxes are controlled at 225, 337 and 450 kg m−2 s−1 by a variable speed gear pump, and the inlet pressures are adjusted from 7.5 to 8.8 MPa. The experimental results in this study are compared with the existing correlations for the supercritical heat transfer coefficient, which generally under-predict the measured data. Pressure drop data agree very well with those calculated by Blasius'' equation. Using the measured data, a new empirical correlation to predict the near-critical heat transfer coefficient has been developed. Most of the experimental data can be predicted by the new correlation within a relative deviation of ±20%. [Copyright &y& Elsevier]

The evolution of the Earth''s climate over geological time is now relatively well known. Conversely, the causes and feedback mechanisms involved in these climatic changes are still not well determined. At geological timescales, two factors play a prevailing role: plate tectonics and the chemical composition of the atmosphere. Their climatic effects will be examined using palaeoclimatic indicators as well as results of climate models. I focus primarily on the influence of continental drift on warm and cold climatic episodes. The consequences of peculiar land sea distributions (amalgamation/dispersal of continental blocks) are discussed. Plate tectonics also drive sea level changes as well as mountain uplift. Marine transgressions during the Mid-Cretaceous favoured warmth within the interiors of continents, although their effect could be very different according to the season. Mountain uplift is also an important factor, which is able to alter climate at large spatial scales. Experiments relative to climatic sensitivity to the elevation of the Appalachians during the Late Permian are discussed. To affect the whole Earth, the chemical composition of the atmosphere appears to be a more efficient forcing factor. The carbon dioxide driven by the long-term carbon cycle has influenced the global climate. Geochemical modelling simulates more or less accurately the long-term evolution of pCO2, which corresponds roughly to the icehouse/greenhouse climatic oscillations. However, the uncertainties on pCO2 are still important because different parameters involved in the long-term carbon cycle (degassing rate, chemical weathering of silicates, burial of organic matter) are not well constrained throughout the past. The chemical composition of the atmosphere is also altered by the emissions of modern volcanic eruptions leading to weak global cooling. The influence of large flood basalt provinces on climate is not yet known well enough; this volcanism may have released huge amounts of SO2 as well as CO2. At last, the chemical composition of the atmosphere may have been altered by the release of methane in response to the dissociation of gas hydrates. This scenario has been proposed to explain the abrupt warming during the Late Palaeocene. [Copyright &y& Elsevier]

The first part of this paper presents an experimental analysis of different hermetic scroll compressors using different methods of injection: the first one is without injection, the second one uses vapor injection and the third one liquid injection. The analysis reveals the influence of these methods on the compressor behavior. A simplified model of the scroll compressor is then proposed that takes into account not only the different internal processes but also the refrigerant injection. It assumes that the refrigerant mass flow rate is affected by a heating-up due to a uniform wall temperature. This fictitious wall is supposed to gain heat from the electromechanical losses and from the discharged gas and to loose heat to the suction and to the ambient. The compression step is considered isentropic up to the adapted pressure and then at constant volume until the discharge pressure. The model is able to compute variables of first importance like the mass flow rate, the electric power and the discharge temperature, as well as secondary variables as suction heating-up, discharge cooling-down, and ambient losses. The validation based on 45 experimental results shows excellent results. [Copyright &y& Elsevier]

In this paper a computationally efficient steady state model for a typical refrigeration reciprocating compressor is proposed. The plenum cavity is modelled using the acoustic plane wave theory, while the compression process is modelled as a one-dimensional gas dynamics equation. Valve dynamic models, based on a single vibration mode approximation, are coupled with the gas dynamics equation and acoustic plenum models. The steady-state solution of the resultant coupled non-linear equations are posed as a boundary value problem and solved using Warner''s algorithm. The Warner''s algorithm applied to compressor simulation is shown to be computationally more efficient as compared to conventional techniques such as shooting methods. Comparisons are based on the number of iterations and time taken for convergence. Effect of operating conditions on the overall compressor performance is also investigated. [Copyright &y& Elsevier]

The Nusselt number variations of supercritical carbon dioxide during in-tube cooling are presented and discussed. Using data presented in this paper as well as prior publications, a new correlation to predict the heat transfer coefficient of supercritical carbon dioxide during in-tube cooling has been developed. The new correlation is presented in this paper. It is based on mean Nusselt numbers that are calculated using the thermophysical properties at the wall and the bulk temperatures, respectively. It is seen that the majority of the numerical and experimental values are within ±20% of the values predicted by the new correlation. [Copyright &y& Elsevier]

This presents a short review on two problems where brittle fracture is involved. In the first one, a hot glass plate is subject to a local stress when drowned into a cold bath. In the region of transition between the cold and hot side, large stresses build up, that can be related accurately to the various coefficients typical of the plate material, heat dilation coefficient, heat conductivity, Young''s modulus, etc. Thanks to thais, one can compare well the experimental results and the theoretical predictions based on the Griffith criterion for the propagation of a straight crack, and for its instability against an undulating mode. In the other problem, one looks at the delay before a bent 2D crystal breaks: this (very long) delay is interpreted as the time required for homogeneous nucleation of a critical Griffith nucleus in a region of the crystal under extension. Although it agrees fairly well with some experimental data, other experimental facts are required to complicate the model by considering a multistep nucleation process. To cite this article: Y. Pomeau, C. R. Mecanique 330 (2002) 249–257. [Copyright &y& Elsevier]

Surgical emphysema affecting a limb is rare. A case is reported of subcutaneous emphysema involving the upper limb resulting from a trivial laceration 2 cm in size on the third interdigital space on the dorsum of the right hand. Gas can form in soft tissues from a wound infection with a gas-forming organism or from a variety of non-infectious causes. One mechanism involves the skin wound acting as a flap valve leading to air being trapped in soft tissues. [ABSTRACT FROM AUTHOR]