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A Four Step Scheme Approach to the Forward-Backward Stochastic Navier-Stokes Equations
Get PDFIn this paper, the authors presented a novel fluid dynamics system, the forward-backward stochastic Navier-Stokes equations in two dimensions for incompressible fluid flows. The well-posedness of the system is obtained through a two-step process. First, certain projections of the system to the finite dimensions are employed, and the existence and uniqueness of solutions in finite dimensions are proved via the four step scheme. Then the Galerkin approximation is used to show the existence and uniqueness of a solution to the system in an infinite dimensional functional setup
Evidence Theory based Uncertainty Design Optimization for Planetary Gearbox in Wind Turbine
Get PDFThe planetary gearbox is an important part of the wind turbine. There are many random uncertain factors in the process of design, production, installation, and use, and these uncertain factors greatly influence the service life and reliability of the planetary gearbox. Therefore, the influence of uncertain factors needs to be considered in the design process to reduce the risk of failure. In this paper, an uncertainty design optimization method based on evidence theory is proposed, which can consider both interval variables and random variables in the optimization process. Then the megawatt wind turbine planetary gearbox is taken as the research object to analyze its uncertainty sources. Finally, the planetary gearbox is optimized by the proposed method. By comparing the results, the design scheme obtained by the method proposed in this paper is more reliable
Lateral Free Vibration of Micro-Rods Using a Nonlocal Continuum Approach
Get PDFThe lateral free vibration of micro-rods initially subjected to axial loads based on a nonlocal continuum theory is considered. The effects of nonlocal long-range interaction fields on the natural frequencies and vibration modes are examined. A simply supported micro-rod is taken as an example; the linear vibration responses are observed by two different methods, including the separation of variables and multiple scales analysis. The relations between the vibration mode and dimensionless coordinate and the relations between natural frequencies and nonlocal parameters are analyzed and discussed in detail. The numerical comparison shows that the theoretical results by two different approaches have a good agreement, which validates the present micro-rod model that can be used as a component of the micro-electromechanical system
Can Seeds Storage Conditions Influence the Quality of Cedrela fissilis Seedlings?
Get PDFSeeds vigor defined in the laboratory does not always reflect the final quality of seedlings produced under nursery conditions or even their survival in plantations. So, we studied the influence of Cedrela fissilis seed storage conditions on its emergence and the morphological quality of produced seedlings. Seeds were collected in October/2011, benefited, conditioned in closed glasses, and stored in three environments for a period of 515 days. Treatments consisted of: I - seedlings produced from seeds without storage (control); II - seedlings produced from seeds stored in a dry chamber; III - seedlings produced from seeds stored in a humid chamber; IV - Seedlings produced from seeds stored in an uncontrolled environment (laboratory). Sowing was performed in 50 cm³ plastic tubes filled with decomposed pinus bark and coconut fiber (50/50 v/v) and packed in a glasshouse. The study analyzed the percentage of seedlings emergence, mean seedlings emergence time, stem diameter, total height, the ratio between total height and stem diameter, shoot length, root length, total, root and shoot dry biomass, and Dickson quality index. Seed storage proved to be a negative factor for the emergence and vigor of C. fissilis seedlings, regardless of the storage environment. In addition, seeds vigor is a preponderant factor to increase seedlings' morphological quality, such as stem diameter and height
Effects of Magnetized, Chelated Iron Foliage Treatments on Foliar Physiology, Plant Growth and Drought Tolerance for Two Legume Species
Get PDFA greenhouse study was conducted to determine the effects of foliar applications of magnetized, chelated liquid iron fertilizer for increasing the drought tolerance of two legumes. Study objectives were to determine the drought tolerance effects of four treatments on foliar gas exchange, soil moisture, and plant growth for velvet bean (Mucuns pruriens) and soybean (Gylcine max) plants. The four foliage treatments included applications with chelated liquid iron fertilizer (2.5 and 5%) with a conventional boom sprayer, with and without magnets in the spray lines. Physiological measurements were collected before foliar treatments and again after a 24-day deficit irrigation schedule. Physicochemical water properties were measured for each of the foliar treatments. Photosynthesis rates were 5.98, 2.04 and 3.19 µmol/m2/s for the control, non-magnetized and magnetized fertilizer treatments (2.5%), respectively, after completing the deficit irrigation schedule. Instantaneous water use efficiency (IWUE) was 0.60, 0.28 and 1.02 for the control, non-magnetized and magnetized fertilizer treatments (2.5%), respectively, after completing the deficit irrigation schedule. Photosynthesis and IWUE increased 56 and 263% for the magnetized fertilizer treatment (2.5%) compared to the non-magnetized foliar treatment, when averaged across both legume species. Photosynthesis and IWUE increased as electrical conductivity increased and oxidation reduction potential (ORP) decreased in absolute terms. A single foliar application resulted in aberrant physiological responses that are contrary to very widely held plant defense theories involving abiotic stressors. The single application improved the photosynthesis and water use efficiency for water stressed legumes emphasizing the need to better understand the relationships between water quality, plant bioenergetics, and stress physiology. Improved drought tolerance in row crops such as dry beans and soybeans, with a single magnetized fertilizer application, would be cost effective and easily adapted into current cropping systems. Interactions among physicochemical water properties, bioenergetics, plant metabolism, and crop stress physiology need to be further investigated in order to improve the quality of irrigation water to enhance drought tolerance of field crops
Use of Foliar Chemical Treatments to Induce Disease Resistance in Rhododendrons Inoculated with Phytophthora ramorum
Get PDFA field study was conducted at the National Ornamental Research Site at Dominican University California (NORS-DUC). The study goal was to evaluate three chemical inducers applied as foliar treatments for controlling Phytophthora ramorum, on Rhododendron x ‘Cunningham’s White’ nursery plants. The inducers were chlorine dioxide (ElectroBiocide), hydrogen peroxide (OxiDate 2.0), and acibenzolar-s methyl (Actigard). Water samples from the electrostatic sprayer were measured for three physicochemical water properties. Visual assessment of plant foliage, based on the Horsfall- Barratt scale, was conducted at three and five months after chemical treatments. Foliar fluorescence (Fv/Fm) was measured over three dates. The success of P. ramorum inoculations were determined using qPCR methods. Visual assessment across both months showed no signs of P. ramorum infection or chemical injury symptoms. However, P. ramorum infection vis-à-vis qPCR analysis was confirmed. The September Fv/Fm results revealed that all the chemical inducer treatments were equivalent to the water treatment, except for Actigard. The qPCR results were in general agreement with the Fv/Fm results indicating that the rhododendrons were successfully inoculated with P. ramorum but were non-symptomatic. The electrostatic sprayer ionized the water droplets, resulting in increased Fv/Fm values for the water treatments 90 days after application. There was a three-month delay in fluorescence responses to the most effective chemical applications, indicating that woody plants may need to be monitored over the long term to determine accurate responses to foliar treatments
Utilizing Chickpea Isolates as a Fortificant to Develop Protein-Dense Yogurt: A Review
Get PDFPulses and dairy products are recognized for their nutritional and functional benefits and are consumed in various forms. Yogurt is considered a source of good quality protein with anti-carcinogenic, hypocholesterolemic properties, and palliating effects on lactose intolerance. Similarly, chickpea is known for its high protein content, low glycemic index, and hypoglycaemic effects. These food ingredients cater to numerous advantages for human health and can address public health issues related to malnutrition or other nutritional deficiencies. With this background, the manuscript explores the possibility of employing chickpea isolates to fortify yogurt to improvise protein content along with sensory and physicochemical properties. So far, the literature has shown that protein extracts, when added to yogurt, result in gaining protein content and overall product quality. The yogurt market is growing, and consumers from different countries have expressed their willingness to purchase fortified yogurts to achieve optimum health. Therefore, developing a new combination of yogurt and chickpea isolates can provide a therapeutic alternative to enhance the nutritional status of the vulnerable population, viz. children, pregnant, lactating mothers, elderly, sportsperson, etc., when a judicious food intake is a must
Origin and Evolution of Geofluids in the Eocene Red-Bed Sandstones of the Dongying Depression, China: Constraints from Fluid Inclusions in Authigenic Minerals
Get PDFFluid inclusion and petrographic study focused on authigenic quartz, annealed microfractures in quartz grains (AMF) and carbonate cement, was performed in red-bed reservoir sandstones from the first member of the Kongdian Formation and the lower fourth member of the Shahejie Formation (Shengli oilfield, East China). Both hydrocarbon and aqueous inclusions are present. Microthermometry and Laser Raman spectroscopes of liquid-rich two-phase inclusions showed that the pressure-correction value of aqueous inclusions is < 15°C. Differences in homogenization temperature and salinity occur between inclusions in quartz and carbonate cements. The liquid-rich two-phase aqueous inclusions were classified into four groups based on the salinity-homogenization temperature plots. The liquid-rich two-phase hydrocarbon inclusions were classified into two groups. The timing of the first-stage diagenetic fluid was before 31.3Ma. Fluids were from syn-depositional water and diagenetic fluids of clay minerals in interbedded mudstones. The timing of the second-stage diagenetic fluid was between 31.3 and 26.4Ma. Fluids were rich in organic acids and were accompanied by filling of small amounts of low maturity oil. The timing of the third-stage diagenetic fluid was between 26.4 and 21.4Ma. Fluids were mainly influenced by dehydration of gypsum-salt rocks and decarboxylation of organic acids. The timing of the fourth-stage diagenetic fluid was after 21.4 Ma. Fluids were influenced by organic acids and carbon acids and were accompanied by filling of mature oil after 10Ma. During the burial history, the red-bed reservoirs experienced the evolution process of early alkaline diagenetic fluids, early acid diagenetic fluids, late alkaline diagenetic fluids and late acid diagenetic fluids, which caused the alternate evolution of multiple alkaline and acid diagenetic environments
VFB Maintenance Methods: Technical and Economic Issues
Get PDFThe VFB system has been extensively studied for almost 30 years. Several plants are installed around the world, with power and energy exceeding some MW and some MWh respectively and new companies are entering the growing market. However, a real widespread application of this technology is hindered by its high capital cost. One method to make these batteries more competitive on the market is to increase their cyclability by means of appropriate maintenance procedures. Some procedures are focused on physical treatments such as the remixing of the positive electrolyte with the negative one, which causes heat generation. Other methods are focused on chemical and electrochemical regeneration procedures which make use of chemical reducing agents, catalysts or electrochemical processes. The latter requires the use of an electrolysis system in order to restore the vanadium oxidation state to the correct ratio in the positive and negative electrolyte. In the first part of this work, an extensive description of VFB technology is presented while in the second part a description of the most important and realizable maintenance procedures with their impact on the system cost is shown, considering both operative and economical points of view
Laboratory Configurations for PCM-TES Materials: A Review
Get PDFThe global energy crisis and the negative impact on the environment of the existing technologies have constrained researchers to capture several types of waste energy using different technologies and materials. For heat, energy harvesting technologies include a major source, the sun, and as an effective storage media, phase change materials. The current review covers experimental laboratory configurations used for thermal energy storage (TES), mainly with phase change materials as working fluids. The required characteristics of PCM-TES materials are covered. Geometric configurations, starting with simple shell-and-tube heat exchanger (HX), other multiple constructive alternatives, plate HX, and also modular HX or fixed and fluidized beds systems are overviewed in order to concentrate on heat transfer characteristics important for TES systems operation and optimization. Emphasis falls on important constructive characteristics for thermal performance, such as the heat charge and discharge rates, within specific temperature ranges, depending on the type of TES fluid used, the energy storage capacity, or density. The advantages and disadvantages of each constructive piece of equipment are critically reviewed. Some comparisons among designs are also included, with an accent on beneficial alterations to improve thermal features