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Optimization of Control Strategies for the Radiant Floor Cooling System Combined with Displacement Ventilation: A Case study of an Office Building in Jinan, China
Get PDF The radiant floor cooling system, as a thermally activated building system, has attracted significant attention as it can save energy consumption and shift the building load. However, due to its characteristic that building thermal mass has a significant influence on the system performance and indoor environment, the control strategies should be seriously accounted for. Moreover, its performance is highly related to the shift condition of cooling load during the daytime and different weather conditions, therefore, realistic operation will cause the increments of peak load if the control strategy is neglected. This study presented two common strategies including intermittent operation and weatherforecast-based control strategies. The radiant floor cooling system combined with displacement ventilation system in a typical office building located in Jinan was established using the TRNSYS program. The results showed that the energy consumption decreased by 3.3% to 7.5% when the different intermittent operation strategies were applied. The weatherforecast- based control strategy can improve indoor thermal environment by increasing/deceasing the water supply flow rate by up to 25% in advance. This study concluded that the application of intermittent operation and weather-forecast based control strategies can regulate the operation of radiant floor system and reduce the building energy use
Case Study of a Solar Chimney in Mansoura, Egypt
Get PDF A solar chimney system was established in Mansoura University which was designed as a square collector with an area of 100m2, the side length 10 m, height 8 m and the diameter 0.3 m. It’s floor was painted with black bitumen and covered with plastic having a thickness of 150 microns. The height of air inlet collector (periphery) was 0.15 m to investigate the effect of environmental temperature on the performance of solar chimney (SCS). Tests were carried out at a wide range of ambient temperatures and solar radiation. In this study, conducted on September 20 and 21, ambient temperature, air inlet temperature, the temperature under collector, the temperature under the chimney, air velocity and solar radiation during the two days were recorded with time. Experimental measurements indicate that as long as the collector air temperature increases, the velocity of air inside the chimney increases
Finite Element Analysis of Creep Crack Initiation in Functionally Graded Materials with Crack Parallel to the Gradient
Get PDF With the advances in material synthesis technologies, functionally graded materials (FGMs) are developed to use in high temperature structurals due to the excellent high temperature mechanical properties. To facilitate wide use of FGMs in high temperature structures, finite element method (FEM) was used in this paper to investigate effects of creep resistant properties gradients on creep crack initiation (CCI) in FGMs, with crack parallel to the gradient. Results indicated that when creep resistant properties increased in the crack growth direction, CCI was retarded by creep properties gradients. However, CCI was accelerated by creep properties gradients when creep resistant properties decreased in the crack growth direction. CCI position occurred in the two symmetric slanted planes of the initial crack, regardless of the gradient variation of creep resistant properties
High Viscosity Oil Development Technology
Get PDF The development of hard-to-recover reserves is now becoming a prerequisite for a successful oil business. Nevertheless, there is still no consensus on what reserves should be classified in this category and what benefits should be received by oil industry workers during their development. At the same time, it is the improvement of the tax system that can spur the development of new technologies for the extraction of “complex” oil and ensure the profitability of its production
Some Contradictions in the Multi-Layer Hele-Shaw Flow
Get PDFAn important problem concerning the Hele-Shaw displacements is to minimize the Saffman - Taylor instability. To this end, some constant viscosity fluid layers can be introduced in an intermediate region (I.R.) between the displacing fluids. However, we prove that very small (positive) values of the growth rates can be obtained only for a very large (unrealistic) I.R. On the contrary, when the I.R. length is constrained by certain conditions (for instance, geological), then the maximum value of the growth constants can not fall below a certain value, not depending on the number of layers. This maximum value is not so small
Management of a Hospıtal Wastes Located in Izmir
Get PDF In this study, the solid wastes produced from a hospital and the present waste management procedures were investigated. The management of solid wastes of the hospital were discussed and some novel waste management techniques were determined to treat the solid wastes. The solid wastes should be collected in special coloured bags, they should be labelled and should be stored in special storage area, and should be disposed by the licensed companies according to Waste Management Regulation. The application of the waste separation at the source throughout the hospital decreases the waste disposal fees. The management of hazardous wastes coming from the hospital should be handled as proposed by the Waste Management Regulations
A Parallel Computation Algorithm for Image Feature Extraction
Get PDF We present a new method for image feature-extraction for learning image classification. An image is represented by a feature vector of distances that measure the dissimilarity between regions of the image and a set of fixed image prototypes. The method uses a text-based representation of images where the texture of an image corresponds to patterns of symbols in the text string. The distance between two images is based on the LZ-complexity of their corresponding strings. Given a set of input images, the algorithm produces cases that can be used by any supervised or unsupervised learning algorithm to learn image classification or clustering. A main advantage in this approach is the lack of need for any image processing or image analysis. A non-expert user can define the image-features by selecting a few small images that serve as prototypes for each class category. The algorithm is designed to run on a parallel processing platform. Results on the classification accuracy and processing speed are reported for several image classification problems including aerial imaging
Other Subordination Results for Fractional Integral Associated with Dziok Srivastava Operator
Get PDF In this paper we have discussed differential subordination properties associated with the fractional integral by using Dziok-Srivastava operato
Fungal Extracts as Biocontrol of Growth, Biofilm Formation, and Motility of Xanthomonas citri subsp. Citri
Get PDF For the present work, Metarhizium rileyi, a common entomopathogenic fungus, was grown in batch conditions in the absence and presence of its host, Spodoptera frugiperda, to obtain secondary metabolites with potential antimicrobial effect. The extraction of secondary metabolites was carried out by using two solvent systems for the biomass (ethyl acetate and methanol), while secondary metabolites present in the supernatant were extracted by using ethyl acetate as extraction solvent. These extracts were evaluated for their inhibitory effect on the growth, biofilm formation, and motility of three Xanthomonas citri subsp. citri strains (Xcc20, Xcc29, and Xcc42). The in vivo effect of these extracts to prevent the development of cankers on grapefruit leaves was also evaluated. M. rileyi biomass ethyl acetate extracts in the presence and absence of its host had a strong inhibitory effect on Xcc strains growth. On the other hand, the presence of S. frugiperda as an elicitor significantly increased M. rileyi’s inhibitory capacity to form a biofilm. A different behavior was observed for the copper resistant strain, Xcc42, for its biofilm formation and swimming capacity since the most active samples were the supernatant extracts in the presence and absence of S. frugiperda. Our results suggest that the most important factor for in vivo canker development is the inhibition of Xcc’s motility since all the extracts that inhibited canker development in vivo were also able to inhibit Xcc20’s motility in vitro. The fact that the extracts can prevent cankers development in vivo indicates they are promising sources of metabolites to prevent the development of this citrus disease
The Role of the Renewable Energy Program in the State of Minas Gerais in the Process of Renewable Sources Expansion
Get PDF The State of Minas Gerais (MG), in Brazil, has significant potential for the exploration of renewable energy, with emphasis on solar, wind and biomass. Since 2013, the State has created the Renewable Energy Program of Minas Gerais – PMER (in Portuguese), aiming the acceleration of the expansion of these renewable sources in the State’s territory. Nonetheless, the use of renewable sources, excluding large hydropower plants, is still irrelevant in the energy matrix of the State. In this way, the present paper aims to perform an effectiveness analysis of the only instrument of the State Government to expand the number of renewable energy projects, and its contribution to achieve the goals of the energy sector of the Brazilian Nationally Determined Contributions – NDCs. In order to do that, the following parameters has been measured: (1) numbers of projects implemented by the program; (2) policy innovation; (3) job creation; (4) climate change mitigation. It is also briefly discussed the efforts of the Program to address actions that promotes energy storage and the needed infrastructure to supply the energy demand through renewable energy only. There is evidence that the expansion of the renewable energy sources at the regional scope has advanced through incentive policies with clearly defined goals and guidelines. However, the five indicators have shown that the PMER does not attend all the requisites in a satisfactory way to perform as the main state public policy of renewable energy expansion. Therefore, promoting a transformation of the energy sector suggests that a balanced mix of public policies must be implemented in the State