Artículos de revistas sobre el tema "Alternate gas flows"
Siga este enlace para ver otros tipos de publicaciones sobre el tema: Alternate gas flows.
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 24 mejores artículos de revistas para su investigación sobre el tema "Alternate gas flows".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore artículos de revistas sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
1
Tyagi, Asha, Vineeta Venkateswaran, Ajai Kumar Jain y Uttam Chandra Verma. "Cost Analysis of Three Techniques of Administering Sevoflurane". Anesthesiology Research and Practice 2014 (2014): 1–6. http://dx.doi.org/10.1155/2014/459432.
Resumen
Background. This study aimed to evaluate and compare total cost of sevoflurane and propofol for 1.0 MAC-hour of anaesthesia, employing three anaesthetic techniques.Methods. Adult patients scheduled for surgical procedures under general anaesthesia anticipated to last approximately an hour were randomized into three groups (n=15each), to receive anaesthesia using one of the following techniques: low flow technique involving induction with propofol, followed by sevoflurane delivered using initial fresh gas flows of 6 L/min till MAC reached 1.0 and then reduced to 0.5 L/min; alternate method of low flow entailing only a difference in fresh gas flow rates being maintained at 1 L/min throughout; the third technique involving use of sevoflurane for both induction and maintenance of anaesthesia.Results. Cost of sevoflurane to maintain 1 MAC-hour of anaesthesia was clinically least with low flow anaesthesia, though statistically similar amongst the three techniques. Once the cost of propofol used for induction in two of the three groups was added to that of sevoflurane, cost incurred was least with the technique using sevoflurane both for induction and maintenance of anaesthesia, as compared to low flow and alternative low flow techniques, a 26% and 32% cost saving, respectively (P<0.05).
2
Dhanasekaran, C. y G. Mohankumar. "Hydrogen Gas in Diesel Engine Using DEE as Ignition Source". Applied Mechanics and Materials 591 (julio de 2014): 150–54. http://dx.doi.org/10.4028/www.scientific.net/amm.591.150.
Resumen
Over the past two decades considerable effort has been taken to develop and introduce new alternate source of energy for the conventional gasoline and diesel. Environmental pollution and uncertainty in cost of petroleum products are the principal driving forces for this movement. The major pollutants from an Diesel engine system are NOx, Smoke, particulate matter, Soot. Several alternative fuels were tried but all of them are carbon based fuels, therefore net carbon based pollutants cannot be reduced. One alternative to carbon-based fuels is hydrogen. Hydrogen a non-carbon fuel only can meet zero emission vehicles standards in future. Hydrogen can be commercially used as a fuel even though it is having a number of technical and economical barriers. Numerous techniques are available for use in C.I. engine such as dual fuel made, by using spark plug, glow plug, DEE as an ignition enhancer. Hydrogen was used in a diesel engine in the dual fuel mode-using diesel as an ignition source in neat form using DEE. In neat form the DEE was introduced in the manifold. In order to have a precise control of hydrogen flow and to avoid the backfire and pre – ignition problems hydrogen was injection in to intake manifold; DEE injection follows the hydrogen injection. DEE mixed with air and flows into the combustion chamber as DEE auto ignites first followed by hydrogen combustion. A single cylinder-four stroke water-cooled naturally aspirated constant speed D.I. diesel engine with a rated output of 3.7 kW at 1500 rpm was used for the experimental purpose. Measurements were taken with respect to the performance, combustion and emission studies.
3
LOMBARDINI, M., D. J. HILL, D. I. PULLIN y D. I. MEIRON. "Atwood ratio dependence of Richtmyer–Meshkov flows under reshock conditions using large-eddy simulations". Journal of Fluid Mechanics 670 (1 de febrero de 2011): 439–80. http://dx.doi.org/10.1017/s0022112010005367.
Resumen
We study the shock-driven turbulent mixing that occurs when a perturbed planar density interface is impacted by a planar shock wave of moderate strength and subsequently reshocked. The present work is a systematic study of the influence of the relative molecular weights of the gases in the form of the initial Atwood ratio A. We investigate the cases A = ± 0.21, ±0.67 and ±0.87 that correspond to the realistic gas combinations air–CO2, air–SF6 and H2–air. A canonical, three-dimensional numerical experiment, using the large-eddy simulation technique with an explicit subgrid model, reproduces the interaction within a shock tube with an endwall where the incident shock Mach number is ~1.5 and the initial interface perturbation has a fixed dominant wavelength and a fixed amplitude-to-wavelength ratio ~0.1. For positive Atwood configurations, the reshock is followed by secondary waves in the form of alternate expansion and compression waves travelling between the endwall and the mixing zone. These reverberations are shown to intensify turbulent kinetic energy and dissipation across the mixing zone. In contrast, negative Atwood number configurations produce multiple secondary reshocks following the primary reshock, and their effect on the mixing region is less pronounced. As the magnitude of A is increased, the mixing zone tends to evolve less symmetrically. The mixing zone growth rate following the primary reshock approaches a linear evolution prior to the secondary wave interactions. When considering the full range of examined Atwood numbers, measurements of this growth rate do not agree well with predictions of existing analytic reshock models such as the model by Mikaelian (Physica D, vol. 36, 1989, p. 343). Accordingly, we propose an empirical formula and also a semi-analytical, impulsive model based on a diffuse-interface approach to describe the A-dependence of the post-reshock growth rate.
4
Adkins, Bruce D., Zach Mills, James Parks II, M. Brennan Pecha, Peter N. Ciesielski, Kristiina Iisa, Calvin Mukarakate et al. "Predicting thermal excursions during in situ oxidative regeneration of packed bed catalytic fast pyrolysis catalyst". Reaction Chemistry & Engineering 6, n.º 5 (2021): 888–904. http://dx.doi.org/10.1039/d1re00007a.
Resumen
Modelling quantifies thermal excursions when a conventional packed bed of coked catalyst is oxidatively decarbonized. The model can indicate when alternate designs, such as radial beds with high gas recycle or moving beds, should be considered.
5
Daya, Rohil, Christopher J. Keturakis, Dylan Trandal, Ashok Kumar, Saurabh Y. Joshi y Aleksey Yezerets. "Alternate pathway for standard SCR on Cu-zeolites with gas-phase ammonia". Reaction Chemistry & Engineering 6, n.º 6 (2021): 1042–52. http://dx.doi.org/10.1039/d1re00041a.
6
Lim, Min Yee, Xinyue Zhang, Jian Huang, Liang Liu, Yutang Liu, Baixiao Zhao, Hui Hu, Furong He, Junjie Xie y Dongsheng Qiu. "Study of Thermal Behavior of Moxa Floss Using Thermogravimetric and Pyrolysis-GC/MS Analyses". Evidence-Based Complementary and Alternative Medicine 2021 (16 de febrero de 2021): 1–7. http://dx.doi.org/10.1155/2021/6298565.
Resumen
Moxa floss is a type of biomass used as the main combustion material in moxibustion, a therapy that applies heat from moxa floss combustion to points or body areas for treatment. Safety concerns regarding moxa smoke have been raised in recent years. Since moxa floss is the source material in moxibustion, its thermal behavior and pyrolysis products would be related to the products formed in moxa smoke. This work aims to understand the thermal behavior of moxa floss and investigate the pyrolysis products generated from moxa floss combustion. Six commercial moxa floss samples of 3 storage years and 10 storage years, and of low, medium, and high ratios, were selected. The kinetic data from moxa floss combustion was carried out by a thermogravimetric analyzer. Pyrolysis-gas chromatography and mass spectroscopy using a gas chromatograph and mass spectrometer equipped with a pyroprobe were used to examine the pyrolysis products. Thermogravimetric profiles for all the samples were overall similar and showed a monotonic weight decrease. The range of intensive reaction temperature occurred between 150°C and 450°C, which was characterized by a major weight loss and accompanied by an exothermal degradation of the main components. The average ignition temperature for the samples of 3 and 10 storage years was 218.3°C and 222.6°C, respectively, which was lower than most herbaceous plants. The identified pyrolysis products include monocyclic aromatic hydrocarbons, polycyclic aromatic hydrocarbons, ketones, acids, and alkanes. All were of relatively low intensities of below 5% in relative abundance. No volatiles were detected in the samples of 10 storage years. The relatively low values of ignition temperature suggested that moxa floss is more combustible and can be ignited more easily than other herbaceous plants. This may explain why moxa floss has remained as the preferred material used for moxibustion over the years.
7
Aquino, Andrea, Davide Picchi y Pietro Poesio. "Modeling the motion of a Taylor bubble in a microchannel through a shear-thinning fluid". E3S Web of Conferences 312 (2021): 05006. http://dx.doi.org/10.1051/e3sconf/202131205006.
Resumen
Applications of multiphase flows in microchannels as chemical and biological reactors and cooling systems for microelectronic devices typically present liquid slugs alternated with bubbles of elongated shape, the Taylor bubbles. These occupy almost entirely the cross-section of the channel and present a hemispherical front and a liquid layer, the lubrication film, which separates the gas from the tube wall. The Taylor bubble perturbs the surrounding fluids activating many transport mechanisms in the proximity of the gas-liquid interface; therefore, the bubble motion significantly influences the heat and mass transfer rates. Although many works deeply investigate the bubble hydrodynamics in Newtonian fluids, the knowledge about the relation between bubble hydrodynamics and rheological properties is insufficient, and studies where the continuous phase exhibits a shear-thinning behavior are missing. Our numerical analysis tries to fill this gap by investigating the motion of a Taylor bubble in a non-Newtonian shear-thinning fluid, modeled by the Carreau viscosity model. First, we validate the results against the Newtonian case and a recent theory for shear-thinning fluids (Picchi et al., Journal of Fluid Mechanics, 2021, 918). Then, we investigate the bubble hydrodynamics far from the validity range of the current models. Finally, we study the scaling of the bubble velocity and lubrication film thickness, extending the current theory to shear-thinning fluids.
8
Dinesh Kumar Venkatesan, Vinayak Bhimsen Hemadri, Chinnapandian Marimuthu y Khathanahalli Mathada Mrityunjayaswamy. "Esterified Papaya Oil and Flamboyant Oil as a Fuel on Single Cylinder Diesel Engine". Journal of Advanced Research in Fluid Mechanics and Thermal Sciences 99, n.º 1 (17 de octubre de 2022): 90–103. http://dx.doi.org/10.37934/arfmts.99.1.90103.
Resumen
The future demand, increase in the price and environmental issues of fossil fuels necessitated the search of renewable alternate called biodiesel which reduces the dependence of fossil fuel import from other countries. The present research investigation outlines a detailed vision on the performance parameters and the exhaust characteristics of the methyl esters of papaya oil (POME) and flamboyant oil (FOME) and its blends on water cooled diesel engine comprising single cylinder running at 1500 rpm. The collected seeds are processed and found to contain oil percentage of 37% and 35% and they are esterified in a reactor to enhance its properties. From the result it is concluded that at maximum load, the blend B25 of papaya biodiesel accounted in better brake thermal efficiency than that of diesel with relatively less exhaust emission, such that the specific fuel consumption, brake thermal efficiency, exhaust gas temperature, smoke density, carbon monoxide emission, hydrocarbon emission and nitrous oxide emission are 0.27 kg/kW-hr, 31.46 %, 318°C, 49.02 Hsu, 0.095 %, 55 ppm and 988 ppm respectively.
9
Trapeznikova, M. A., A. A. Chechina y N. G. Churbanova. "Simulation of Vehicular Traffic using Macro- and Microscopic Models". Computational Mathematics and Information Technologies 7, n.º 2 (13 de julio de 2023): 60–72. http://dx.doi.org/10.23947/2587-8999-2023-7-2-60-72.
Resumen
To effectively regulate traffic on highways and networks of modern megacities, it is necessary to introduce Intelligent Transport Systems, which include many innovative solutions, in particular, mathematical models for describing the dynamics of traffic flows.The article is devoted to a brief description of the current state in this area in its development — from the simplest macroscopic and microscopic models that have become classic to modern developments.Special attention is paid to the original multilane models developed by the authors of the article within both approaches.The macroscopic model is based on the quasigasdynamic approach, while the microscopic one uses the ideology of cellular automata and constitutes a generalization of the Nagel-Schreckenberg model for the multilane case.The difference in the representation method and the mathematical apparatus for the mac-roscopic and microscopic description of traffic flows is briefly described, followed by the review of the main models at different stages of their development, presented by foreign and Russian authors.Special attention is paid to the three-phase theory of Boris Kerner and models built in the framework of this theory.Examples of modern software for traffic modeling are given.The original quasigasdynamic model of traffic flows, which uses the continuum approximation and is constructed by analogy with the well-known model of gas dynamics, is briefly described. Due to the introduction of the lateral speed, the model is generalized to the multilane case.An original microscopic model based on the cellular automata theory and representing a generalization of Nagel- Schreckenberg model for the multilane case is described. The model has been further developed by taking into account various driving strategies and behavioral aspects.The article presents a brief overview of the state of the art in the field of mathematical modeling of traffic flows, as well as original macroscopic and microscopic models developed by the authors for the case of multilane traffic.
10
Prashantha, B. G., D. R. Swamy, Bhimasen Soragaon y T. S. Nanjundeswaraswamy. "Design Optimization and Analysis of Thermoacoustic Refrigerators". International Journal of Air-Conditioning and Refrigeration 28, n.º 03 (22 de julio de 2020): 2050020. http://dx.doi.org/10.1142/s2010132520500200.
Resumen
Thermoacoustic refrigeration, a novel technology, uses eco-friendly gases like helium, air or the mixture of noble gases as working substances in the absence of moving parts. The design, optimization and analysis of thermoacoustic refrigerators using helium and air as oscillating gases are discussed. Pure helium is chosen since it is proven as the best and economical working gas compared to the alternate pure or the mixture of noble gases. Air is chosen since it is abundant in nature and the least cost of the pressurized dry air cylinders. The design optimization strategies discussed in this paper serve as a guide for aspiring researchers in the design and development of thermoacoustic coolers. Cooling power as a function of stack diameter is discussed. Theoretical results of the optimized coolers are compared with DeltaEC simulation results for validation and are in agreement with each other.
11
Varikunta, Saikrishna y Ashwani Kumar Sharma. "GAMS applications to capacitors location and its sizing in a RDS". International Journal of Engineering, Science and Technology 14, n.º 3 (30 de agosto de 2022): 21–28. http://dx.doi.org/10.4314/ijest.v14i3.3s.
Resumen
This paper presents a new approach for finding capacitor's location and it's sizing in a radial distribution system (RDS) optimally with an aim of reducing the active power loss. In this paper, the problem of minimizing power loss is converted into a Mixed Integer Non-Linear Program (MINLP) problem, and it will be solved by using Generalized Algebraic Modeling Systems (GAMS) software with MINLP-SBB Solver. The proposing GAMS approach is tested on IEEE 10 bus RDS. By using GAMS, the programming will be simple and more accurate results can be achieved with less execution time. The MATLAB R2020b is used to run the load flows program and analyze results. The results are compared with the other optimization techniques results.
12
Saeed, Muhammad, Muhammad Zafar, Abdul Razzaq, Shenawar Ali Khan, Zakir Khan y Woo Young Kim. "Visible-Light-Active Zn–Fe Layered Double Hydroxide (LDH) for the Photocatalytic Conversion of Rice Husk Extract to Value-Added Products". Applied Sciences 12, n.º 5 (23 de febrero de 2022): 2313. http://dx.doi.org/10.3390/app12052313.
Resumen
One of the major causes of excess CO2 in the atmosphere is the direct burning of biomass waste, which can be obviated by the photocatalytic biomass conversion to useful/valuable chemicals/fuels, a sustainable and renewable approach. The present research work is focused on the development of a novel Zn–Fe LDH by a simple co-precipitation method and its utilization for the photocatalytic conversion of a rice husk extract (extracted from rice husk by means of pyrolysis) to value-added products. The synthesized, pure Zn–Fe LDH was characterized by various analytical techniques such as XRD, SEM, FTIR, and UV–Visible DRS spectroscopy. The rice husk extract was converted in a photocatalytic reactor under irradiation with 75 W white light, and the valued-added chemicals were analyzed by gas chromatography–mass spectrometry (GC–MS). It was found that the compounds in the rice husk extract before the photocatalytic reaction were mainly carboxylic acids, phenols, alcohols, alkanes (in a small amount), aldehydes, ketones, and amines. After the photocatalytic reaction, all the carboxylic acids and phenols were completely converted into alkanes by complex reactions. Hence, photocatalytic biomass conversion of a rice husk extract was successfully carried out in the present experimental work, opening new avenues for the development of related research domains, with a great potential for obtaining an alternate fuel and overcoming environmental pollution.
13
Dhawan, Sandeep. "Technology Focus: Well Integrity (January 2024)". Journal of Petroleum Technology 76, n.º 01 (1 de enero de 2024): 74–75. http://dx.doi.org/10.2118/0124-0074-jpt.
Resumen
The context of last year’s Well Integrity Technology Focus was the repurposing of existing oil and gas wells for carbon storage, flow-wet material conformity, and associated integrity risks. Typically, oil and gas producing wells are abandoned toward the end of their life cycles with reservoir pressures depleted compared with the virgin pressures. Carbon capture and storage (CCS) projects, however, present different operating conditions. First, the pressurized containment sites have a higher life expectancy, say, between 50 and 100 years. Second, the containment pressure is possibly higher than the virgin pressure. The overpressure limit is dependent on several factors, especially the caprock sealing capacity. It goes without saying that CCS storage in wells requires long-term integrity (i.e., for the entire project life cycle). It is well-known that barriers such as cement and casings deteriorate over time. Deterioration of barriers may be accelerated by chemical reaction with carbon dioxide or thermal cycling. Hence, these storage sites could present unique life-cycle integrity risks perhaps never experienced by the oil and gas industry. To further explain the scenario, a possible breach of the confining strata resulting in pressure communication to the overburden means CO2 finding its way through the deteriorated well barriers of any active or shut-in well, resulting in CO2 ingress to the upper formations; groundwater contamination; or, in a worst-case scenario, appearance at the surface. Therefore, one of the important subsurface aspects of a CCS site is the presence of two seals (i.e., primary and secondary), with sealing capacity of both caprocks characterized robustly. Lack of double barriers or improper characterization of these confining strata could present a scenario wherein CO2 flows into overburden (i.e., above the caprock). The wells’ outer annuli then could become a potential path of least resistance for CO2 to migrate further up. Such situations can defy the primary objective of CCS projects and can require mitigation with proper attention to detail following the “as low as reasonably practicable,” or ALARP, principle. The scenario discussed is unique and complex and requires continuous managing and monitoring of CCS storage sites. Furthermore, the role of artificial intelligence and automation is seen as imperative during the operational stage of the project. In addition to the primary paper selections synopsized here, three SPE papers focusing on artificial intelligence and machine learning as tools for well integrity management are recommended as alternates for further reading. Recommended additional reading at OnePetro: www.onepetro.org. SPE 212479 Improve Well Integrity Using an Annular Barrier AI Tool by Eirik Time, Equinor, et al. SPE 211537 Transforming Production-Phase WIMS to a Game Changer Smart Well Integrity Monitoring System With Real-Time Automated Engineering Analytics by Mohammed Jasem, ADNOC, et al. SPE 216600 Paradigm Shift in Well Integrity Management Through the Use of Autonomous Wireless Well Intervention Robots by Julio Q.M. Guedes, Ouronova, et al.
14
Prabhu, Sharad V. y Shripad P. Mahulikar. "An Alternate Approach to Friction Factor Computations Based on Entropy Generation in Gas Micro Flows". SSRN Electronic Journal, 2017. http://dx.doi.org/10.2139/ssrn.3101266.
15
Rocheleau, R. E., S. C. Jackson., S. S. Hegedus y B. N. Baron. "Properties of a-Si:H and a-SiGe:H Films Deposited by Photo-Assisted CVD". MRS Proceedings 70 (1986). http://dx.doi.org/10.1557/proc-70-37.
Resumen
ABSTRACTChemical vapor deposition techniques, in particular plasma enhanced CVD, have been used to produce high quality a-Si:H materials. Continuing research is directed toward increased device performance, improved stability, and translation of scale to commercial production. A part of this effort is the evaluation of alternate CVD techniques which in addition to providing technical options for high efficiency and long term stability are likely to lead to improved understanding of the relationships between deposition processes and material properties. A relatively new technique for depositing a-Si:H is photo-CVD which utilizes ultraviolet light to initiate the decomposition of silane or disilane. The best results from both materials properties and device efficiency points of view have been achieved using mercury sensitized photo-CVD. Recently, a 10.5% efficient a-Si:H p-i-n photovoltaic cell, fabricated by photo-CVD, was reported [1]. A limitation in photo-CVD has been preventing deposition on the UV transparent window. In this paper we describe a new photo-CVD reactor with a moveable UV-transparent Teflon film and secondary gas flows to eliminate window fouling. The deposition and opto-electronic characterization of intrinsic a-Si:H and a-SiGe:H and p-type a-SiC:H are described. Finally, preliminary results of p-i-n solar cells are presented.
16
Wang, Xin, Pinakin Soni, Amrish Patel, Dejan Nikolic, Alexander Heide, Jiaming Dong, Vaibhav Maheshwari, Nadja Grobe, Shivanand Nayak y Peter Kotanko. "#598 Successful application of allo-hemodialysis in a porcine model of embolization-induced acute kidney injury". Nephrology Dialysis Transplantation 39, Supplement_1 (mayo de 2024). http://dx.doi.org/10.1093/ndt/gfae069.752.
Resumen
Abstract Background and Aims Annually, millions of kidney patients, primarily in low- and low-middle income nations, die prematurely due to the lack of affordable kidney replacement therapy. We propose a novel, low-cost alternative dialysis modality called allo-hemodialysis (alloHD), where blood of a patient with kidney failure flows counter-current to the blood of a healthy subject (“buddy”) through the dialyzer [1]. Uremic solutes and excess fluid are then excreted by the buddy's healthy kidneys. We have already demonstrated the technical feasibility of alloHD in pigs with acute kidney injury (AKI) induced by renal artery ligation [2]. In this study, we explored alloHD in a less invasive porcine model of AKI induced by renal artery embolization. Method The protocol was approved by the Committee for the Purpose of Control and Supervision of Experiments on Animals (CPCSEA), New Delhi, India. We studied two female Yorkshire pigs (weight 80-90 kg) with central venous catheter as vascular access. AKI was induced by embolization of both kidneys by transcatheter deployment of Contour™ Poly Vinyl Alcohol particles (Boston Scientific, Marlborough, MA, USA). The AKI pig and the buddy pig were connected to the dialysate and blood compartments, respectively, of a Nipro Cellentia 17H dialyzer. The AKI pig was then dialyzed for 4 hours against the healthy buddy pig. During alloHD, both pigs were anticoagulated with heparin (5,000 IU/h) and the buddy pig was sedated with 1-2% isoflurane gas. Blood samples were collected before, during, and after alloHD for measurements of blood urea nitrogen (BUN) and creatinine. Results We performed nine alternate day alloHD sessions with the same pair of pigs. During alloHD, BUN and Creatinine levels declined in the AKI pig (Fig. 1) and increased—as expected—transiently above baseline in the buddy pig and then trended towards baseline post-dialysis (Fig. 1). We found no indication of hemolysis or coagulation of the extracorporeal circuit in any of the nine alloHD sessions. The animals were sacrificed after the 9th session. Conclusion We demonstrated the feasibility of alloHD in a porcine embolization AKI model. This study corroborates and complements our previous experience with alloHD in a porcine model of AKI induced by renal artery ligation. Given these promising results, we are investigating the potential for advancing to a clinical trial.
17
"Prepaid Electricity Billing System using Arduino". International Journal of Recent Technology and Engineering 8, n.º 5 (30 de enero de 2020): 1757–59. http://dx.doi.org/10.35940/ijrte.e6322.018520.
Resumen
The World is changing very fast. With the advancement in technology, the needs and demands for various resources is increasing too. Earlier, when the technology was not that advanced. We, Humans, never thought about saving resources and never thought about efficiency, as everything was abundant. However, with this fast growing world and increasing demands, Scientists have started worrying about the Sustainable Development. The pace at which all these resources are being used, soon they will be fully depleted. Already the need for saving the resources like Petroleum and Natural gas has been understood and alternate resources are like electricity are used to power the devices dependent on Petroleum and Natural Gas. The main thing is that we are not realizing the fact that shifting to some other resource like Electricity and ultimately getting dependent on it will endanger that resource too. Today, Electricity is used as a major resource in our day-to-day lives. Electricity is powering every machine used by us daily. From Powering Fan, Ac, TV, Refrigerator to powering microwave, electric chimney, Induction Plate, and even Vehicles. We are overusing Electricity so much that there is a need to reduce its overuse. Otherwise, the day is not far when Scientists will have to start looking for some other alternate resource also. Being renewable resource, it is cheaper and easily available at this moment but soon the situations might change. In today’s Electricity Distribution System, there are many flaws. There is no measure for reducing the overuse, no measure for people not paying their bill, no measure for people who secretly steal the electricity. All this can be solved by using a Prepaid System that will enforce customers to pay before use, so no defaulters
18
Prashantha, B. G., G. S. V. L. Narasimham, S. Seetharamu y K. Manjunatha. "Effect of Gas Blockage on the Theoretical Performance of Thermoacoustic Refrigerators". International Journal of Air-Conditioning and Refrigeration 29, n.º 03 (septiembre de 2021). http://dx.doi.org/10.1142/s2010132521500267.
Resumen
Thermoacoustic refrigeration is an emerging green, novel and promising alternate technology compared to vapor compression refrigerator systems for domestic cooling. It uses environmentally benign gases like air or helium or the mixture of inert gases as working substances and has no moving parts, no lubrication and no vibration. The cooler is designed and optimized with helium and air as refrigerants operating at 10[Formula: see text]bar with 3% drive ratio for the temperature difference of 28[Formula: see text]K and stack diameter of 200[Formula: see text]mm using linear thermoacoustic theory. In this paper, the effect of gas blockage (porosity) of the spiral-stack heat exchanger system ranging from 45% to 85% on the theoretical performance of the cooler is discussed. The one-third and one-fourth wavelength convergent–divergent resonator designs are optimized with air and helium as working substances, respectively, to improve performance and power density. The optimized coolers show best performance with 85% porosity. The theoretical results are validated with DeltaEC software simulation results. The simulation results show the coefficient of performance and cooling capacity of 0.93 and 219[Formula: see text]W for helium and of 0.50 and 139[Formula: see text]W for air, respectively, at the cold heat exchanger temperature of 0∘C.
19
"Point source pollution and climate change impact from sequential batch reactor wastewater treatment plant". Issue 1 20, n.º 1 (4 de diciembre de 2017): 33–41. http://dx.doi.org/10.30955/gnj.002231.
Resumen
Since sequential batch reactor (SBR) system is sequentially removes carbon, nitrogen and phosphorous in a single reactor by maintaining anoxic and aerobic stages, it recently has attracted a great deal of interest. This study evaluates the impact of wastewater treatment plant (WWTP) with a SBR system on a creek which is the influent tributary to Aegean Sea. Accordingly, this study demonstrates (1) the treatment efficiency of full-scale WWTP; (2) how WWTP influences creek’s water quality from 2012 to 2015; (3) how creek influences receiving body’s water quality; and (4) the potential climate change impact of a SBR treatment system. The study shows that SBR treatment plant complies with standards set by Turkish Legislations with 4-year average of 62 % SS, 71 %BOD, 62 % COD, 32 % TN and 31 % TP removal but the accumulation of pollutants occurs during low flows when point source is dominant. This is the case in the downstream of treated WWTP discharge point. The potential impact of treatment plant on climate change was calculated in terms of greenhouse gas emissions (GHG). The annual methane emissions from SBR alternated from minimum of 68.71 to maximum 248.99 tCO2e. Total emissions (CH4, N2O and emission due to electricity usage) from a full-scale SBR were calculated as 144.22 tCO2e, 318.34 tCO2e, 474.79 tCO2e and 996.62 tCO2e from 2012 to 2015, respectively.
20
PATEL, Bhaveshkumar y Ashok PAREKH. "Energy, exergy and entropy analysis with R1234yf as an alternate refrigerant to R134a of automobile air conditioning system". Journal of Thermal Engineering, 2 de marzo de 2023, 101–14. http://dx.doi.org/10.18186/thermal.1429400.
Resumen
A major portion of the worldwide emissions arise from mobile air-conditioning systems with hydrofluorocarbon refrigerant as working substance and which is one of major cause for the greenhouse effect. R134a refrigerant having GWP of 1400 has been extensively used in car air conditioning. To reduce greenhouse gas emissions, the current R134a refrigerant must be phase out as per Kigali Amendment. The present study deals with cooling load calculation of car model by heat balance method as per ASHRAE standard using local climate condition. Further, thermodynamic analysis of R1234yf as an alternate refrigerant to R134a has been carried out for automobile air conditioning system. The required properties of refrigerants are extracted from Engineering Equation Software. The thermodynamic analysis is carried out to study the effect of operating parameters viz. condensing temperature, evaporating tempera-ture, degree of superheating and degree of subcooling on COP, EDR, exergy efficiency and entropy generation. The previous literature reports mainly focus on separate study of either cooling load calculation or energy analysis or exergy analysis of R1234yf and R134a for au-tomobile air conditioning system, while this paper presents the comprehensive study of new low GWP R1234yf as an alternate refrigerant to R134a in automobile air conditioning system with cooling load calculation including the concept of energy, entropy and exergy analysis. The percentage difference in COP between R134a and R1234yf system varies from 2.44 % to 4.78 % while percentage difference in EDR varies from 6.79 % to 2.87 % when evaporating temperature varied from -10 °C to 10 °C. With 12 °C of superheating at compressor inlet, the COP of R134a is 3.9 whereas COP of R1234yf is 3.75, which makes 3.85 % lower than that of R134a. The R1234yf has 4.78 % lower value of exergy efficiency as compared to that of R134a at evaporating temperature of -10 °C and it is found that maximum exergy destruction takes place in compressor.
21
Han, Jiaxiang, Qiaodong Bai, Shijian Zhang y Chunsheng Weng. "Experimental study on propagation mode of rotating detonation wave with cracked kerosene gas and ambient temperature air". Physics of Fluids, 3 de julio de 2022. http://dx.doi.org/10.1063/5.0101801.
Resumen
In order to obtain the propagation characteristics of rotating detonation wave (RDW) of cracked kerosene gas (CKG) and ambient temperature air, a series of experiments were carried out at different cracking kerosene and air mass flow rates. The propagation mode of RDW was analyzed in detail, and the ignition range of CKG and air was evaluated. In the experiment, the propagation modes of rotating detonation mainly include single rotating detonation wave (SRDW) mode, reversed single rotating detonation wave (RSRDW) mode and mixed mode. In mixed mode, SRDW and two-counter rotating detonation wave (TCRDW) modes alternate. Combined with high-speed photography and pressure curve, the mechanism of mode transition of rotating detonation propagation is analyzed. The RSRDW mode is considered to be a transitional mode in the process of equivalence ratio change. The mixed mode is an unstable RDW propagation state due to the improper ratio of fuel and oxidizer. Based on a substantial number of experimental data, the ignition ranges of CKG are summarized. Under the experimental conditions in this paper, the equivalence ratio range of CKG can be detonated is 0.63-0.99. RDW is favorable to be formed in lean oil state. When the equivalence ratio is 0.99, the maximum RDW velocity is 1077.79 m/s. When the mass flow rate of cracking kerosene is 42 g/s, the ignition initiation range is the widest. As the mass flow rate increases or decreases, the initiation range is gradually reduced.
22
Binet, Flavien, François Saunier y Manuele Margni. "Assessing the Mitigation Potential of Environmental Impacts From Circular Economy Strategies on an Industrial Sector and Its Value Chain: A Case Study on the Steel Value Chain in Quebec". Frontiers in Sustainability 2 (11 de noviembre de 2021). http://dx.doi.org/10.3389/frsus.2021.738890.
Resumen
This research project aims to evaluate the potential reduction of environmental impacts from circular economy strategies on an industrial sector at a regional scale with a case study on Greenhouse Gas (GHG) emissions in Quebec's steel industry and its value chain. To do so, an integrated model has been created based on the matrix approach, building on material flow analysis (MFA) tracking flows and stocks and on life cycle assessment (LCA) to compute direct (from the activity, e.g., combustion process) and indirect (from the supply chain, e.g., production of raw material inside or outside of region) emissions. This theoretical model is designed to be applied to any emissions or environmental impacts from a specific sector in a given region and enable to model the effects of circularity strategies to both flows and related environmental impacts. The overall mitigation potential of individual or combined circular economy strategies on a specific sector could thus be evaluated across its entire value chain. In the case study, a set of the most promising circular strategies applicable in the Quebec context were identified, and the GHG reduction potential within and outside the province is calculated and compared with actual emissions. Six circular strategies were analyzed acting at three different levers, namely, GHG/material (increase iron recycling rate, switch to hydrogen-based reduction production), material/product (reduce weight of vehicle, limit over-specification in building construction), and product/service (increase buildings and cars lifetime, increase car-sharing), and therefore impact rather direct or indirect emissions on different stages of the steel life cycle. Combining these six strategies into a consolidated scenario shows that a circular-driven economy allows to cut down GHG emissions of the cradle-to-gate steel industry value chain by −55%, i.e., 1.67 Mt CO2e. Taking into account use phase of steel, overall reductions are estimated at −6.03 Mt CO2e, i.e., −30% of the whole life cycle.
23
Ullah, Izhar, Tim Burdett, Lesley M. Wright, Je-Chin Han y Ching-Pang Lee. "Evaluation of Wavy-Trailing-Edge Film Cooling Versus Pressure Side Cutback Cooling". Journal of Thermophysics and Heat Transfer, 24 de enero de 2024, 1–9. http://dx.doi.org/10.2514/1.t6745.
Resumen
This study measures the film cooling effectiveness along the trailing edge (TE) of a turbine blade in a linear cascade. The film cooling effectiveness is measured and analyzed using the pressure-sensitive paint (PSP) technique. Two different TE designs are investigated: the standard pressure side cutback and the new alternating discharge design (referred to as a wavy-TE design). The alternating discharge design is a new design with a wavy structure between the pressure and suction surfaces at the TE. The new wavy structure allows the coolant to discharge from the TE so that it alternates between the pressure and suction surfaces. Testing is carried out in a five-blade, linear, steady-state cascade with inlet and exit Mach numbers of 0.20 and 0.30, respectively. The freestream turbulence intensity is measured to be 10.5% upstream of the blade leading edge. Coolant-to-mainstream mass flow ratios (MFRs) vary from 0.30 to 1.25% and coolant-to-mainstream density ratios (DRs) of 1.0, 1.5, and 2.0 are examined. A positive MFR and DR effect is witnessed. The results demonstrate the potential of the alternating discharge as a promising TE design and provide gas turbine designers with an improved TE cooling scheme.
24
"The biophysical modelling of the diffusion in the living systems". Medical & Clinical Research 8, n.º 7 (1 de julio de 2023). http://dx.doi.org/10.33140/mcr.08.07.01.
Resumen
The transport phenomena mean the variation in time and space of generalized forces when they generate flows for which conservation laws apply. According to the general definition, the diffusion is a mass transportation under the action of a generalising force, which can be the concentration gradient, the pressure gradient, etc. The diffusion is explained on the basis of the spontaneous movement of the molecules which have the tendency to spread in equal numbers in each subspace tendency which arises from the concentration gradient. The diffusion is a frequently found phenomenon: with diffusion, the respiratory gas exchange takes place between the air in the alveoli, blood and cellular cytoplasm, the nutritive substances diffuse from the thin intestine into blood and further away in the tissues, the diffusion lays at the basis of the white cells’ chemotactism, the olfaction happens when the molecules of the smelling substances spread in the air reach the cells of the olfactory mucosa. A particular case of diffusion is dialysis, which consists in the diffusion thought semipermeable membranes of the substances with a molecule smaller than the membranes pores. The dialysis takes place up to the equalising of the concentration in the two parts of the membrane.