Aquaporins belong to a family of small, transmembrane proteins that form channels selectively permeable for water. Some of them known as aquaglyceroporins also enable transportation of other small ...molecules such as glycerol, urea or ammonia. To date, 13 isoforms of aquaporins has been discovered in mammals (AQP0 - AQP12), 9 of which is localized in different parts of the renal tubular epithelium. In recent years, particular interest has been paid to aquaporins selectively permeable only to water molecules, determination of their localization and expression allowed to define the role of these proteins in renal excretion of water and their importance in the development of diseases. Alas, thus far the role in the physiological processes of the aquaglyceroporins localized in the kidneys has not been fully determined. This review summarizes our current knowledge on additional transport functions of renal AQPs (AQP3, AQP6, AQP7 and AQP8). On the basis of the information gathered and the opinions by many authors, it has been found that aquaglyceroporins are most probably the key element in the renal regulation of nitrogen balance and maintenance of the correct pH of body fluids. Elucidating additional transport functions of AQPs in the kidney will improve our understanding of the renal function in heath and diseases. The presented in this article prospect on renal aquaglyceroporin hopefully will stimulate future research in both basic and clinical fields.
The article describes the influence of optimization parameters on the efficiency of aluminium melt refining by using physical modelling. The blowing of refining gas, through a rotating impeller into ...the ladle is a widely used operating technology to reduce the content of impurities in molten aluminium, e.g. hydrogen. The efficiency of this refining process depends on the creation of fine bubbles with a high interphase surface, wide-spread distribution, the residence time of its effect in the melt, and mostly on the wide-spread dispersion of bubbles in the whole volume of the refining ladle and with the long period of their effect in the melt. For physical modelling, a plexiglass model on a scale of 1:1 is used for the operating ladle. Part of the physical model is a hollow shaft used for gas supply equipped with an impeller and also two baffles. The basis of physical modelling consists in the targeted utilization of the similarities of the processes that take place within the actual device and its model. The degassing process of aluminium melt by blowing inert gas is simulated in physical modelling by a decrease of dissolved oxygen in the model liquid (water).
The three species in the blue mussel complex (Mytilus edulis, Mytilus galloprovincialis and Mytilus trossulus) show varying levels of hybridisation wherever they occur sympatrically. The spatial ...variation in hybridisation patterns is potentially governed by environmental conditions, larval dispersal and aquaculture practices. Commercial mussel cultivation has been shown to increase hybridisation through introduction of non-native species or spat transfer. There is evidence that mussel cultivation may promote commercially less desirable phenotypes (e.g. fragile shells), however, to what extent hybridisation impacts aquaculture is currently not clear. The aim of this review is to summarize the available information on Mytilus hybridisation patterns in Europe and their promotion through aquaculture practices in order to shed light on the overall implications for the aquaculture industry.
This paper deals with the possibilities of using physical modelling to study the degassing of metal melt during its treatment in the refining ladle. The method of inert gas blowing, so-called ...refining gas, presents the most common operational technology for the elimination of impurities from molten metal, e.g. for decreasing or removing the hydrogen content from liquid aluminium. This refining process presents the system of gas-liquid and its efficiency depends on the creation of fine bubbles with a high interphase surface, uniform distribution, long period of its effect in the melt, and mostly on the uniform arrangement of bubbles into the whole volume of the refining ladle. Physical modelling represents the basic method of modelling and it makes it possible to obtain information about the course of refining processes. On the basis of obtained results, it is possible to predict the behaviour of the real system during different changes in the process. The experimental part focuses on the evaluation of methodical laboratory experiments aimed at the proposal and testing of the developed methods of degassing during physical modelling. The results obtained on the basis of laboratory experiments realized on the specific physical model were discussed.
Introduction:
Research has documented higher smoking prevalence with unemployment and greater difficulty with gaining re-employment for those who smoke. Using photo elicitation methods, we sought to ...gain a deeper understanding of the connection between job-seeking and tobacco use.
Methods:
Unemployed daily smokers (18 men, 1 woman) were recruited from the San Francisco Employment Development Department (EDD) and provided disposable cameras with 27 exposures and a list of 20 photo prompts related to job-seeking and tobacco. Study staff reviewed the photos with the participants and audio-recorded their narratives. The photos and narratives were coded for themes.
Results:
Of 363 photos, the most frequent photo imagery related to transportation (n = 56, 15.4%), work or education (n = 39, 10.7%), and littered cigarettes (n = 39, 10.7%). Narrated themes centered on motivators to quit smoking (255 mentions from 15 participants); people, places, and things associated with smoking (248 mentions, 16 participants); and motivators to secure work (157 mentions, 13 participants). The intersection of smoking and unemployment received 92 mentions from 11 participants, with 60 mentions (8 participants) identifying smoking as a barrier to re-employment.
Conclusions:
Both motivators to quit and associated smoking cues were salient in the environments of job-seeking smokers. Struggles with quitting and perceptions that smoking is harming re-employment success suggest the potential for offering tobacco treatment in EDD settings. With permission, the photos and themes have been incorporated into a tobacco treatment intervention for job-seeking smokers.
The paper describes research and development of aluminium melt refining technology in a ladle with rotating impeller and breakwaters using numerical modelling of a finite volume/element method. The ...theoretical aspects of refining technology are outlined. The design of the numerical model is described and discussed. The differences between real process conditions and numerical model limitations are mentioned. Based on the hypothesis and the results of numerical modelling, the most appropriate setting of the numerical model is recommended. Also, the possibilities of monitoring of degassing are explained. The results of numerical modelling allow to improve the refining technology of metal melts and to control the final quality under different boundary conditions, such as rotating speed, shape and position of rotating impeller, breakwaters and intensity of inert gas blowing through the impeller.
The efficiency of vacuum steel degassing using RH methods depends on many factors. One of the most important are hydrodynamic processes occurring in the ladle and vacuum chamber. It is always hard ...and expensive to determine the flow character and the way of steel mixing in industrial unit; thus in this case, methods of physical modelling are applied. The article presents the results of research carried out on the water physical model of RH apparatus concerning the influence of the flux value of inert gas introduced through the suck legs on hydrodynamic conditions of the process. Results of the research have visualization character and are presented graphically as a RTD curves. The main aim of such research is to optimize the industrial vacuum steel degassing process by means of RH method.
The aim of this paper will be to present new knowledge and experience from numerical and physical modelling of metallurgical processes at the Department of Metallurgy, VSB - Technical University of ...Ostrava in Czech Republic and to explain especially the principle of tundish process simulations. The numerical modelling was realized by the CFD program FLUENT. The paper describes the pre-processing, processing and post-processing phases of numerical modelling. The physical modelling of the steel flow verification is based on a monitoring of the time dependency of concentration changes during experiments for individual tundish outlets. There exist two basic methods of KCl concentration change utilization in this "water" physical tundish modelling methodology. The utilization of mentioned methods are discussed and possible future developments are outlined for research of tundish steel intermixing.
Celem artykułu jest przedstawienie wyników i doświadczeń z numerycznego i fizycznego modelowania procesów metalurgicznych w Zakładzie Metalurgii, VSB - Uniwersytet Techniczny w Ostrawie (Republika Czeska) i wyjaśnienie zasady symulacji procesów mieszania stali w kadzi pośredniej. Program CFD FLUENT posłużył do modelowania numerycznego. W artykule opisano pre-processing, processing i post-processing modelowania numerycznego. Weryfikację modelowania fizycznego przepływu stali dokonano w oparciu o eksperymenty, w których monitorowano zmianę stężenia w czasie dla poszczególnych stref kadzi. Istnieją dwie podstawowe metody wykorzystania zmian stężenia KCl w wodzie. Omówiono wykorzystanie wymienionych metod i możliwości przyszłego rozwoju badań mieszania stali w kadzi pośredniej.
This paper deals with the possibilities of using physical modelling to study the slag entrainment in the tundish. A level of steel in the tundish is changing during sequential continuous casting. The ...most significant decrease in the steel level occurs when replacing ladles. It is generally known that if the height of steel level in the tundish drops below a certain critical level, it may generate vortexes over the nozzles and as a consequence entrainment of tundish slag into individual casting strands can occur. Thus, it is necessary to identify the critical level of steel for specific operational conditions. In this paper, the development of physical modelling methodology is described as well as physical model corresponding to operational continuous casting machine No. 2 in Třinecké železárny, a.s. The obtained results are discussed.
This paper deals with the issue of physical modelling of vortexes creation and tundish slag entrainment over the mouth of the nozzle into the individual casting strands. Proper physical model is ...equivalent to the operational continuous casting machine No. 2 in TŘINECKÉ ŽELEZÁRNY, a.s. Physical modelling methodology and simulated operational conditions are shortly described. Physical modelling was used for the evaluation of current conditions of steel casting at the application of different impact pads in the tundish. Further, laboratory measurement on the physical model aiming the determination of exact critical periods of vortexes creation and study of the slag entrainment as a consequence of changes in surface level during the tundish refilling to standard level were realised. The obtained results were analysed and discussed.
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