Search results for: fabric strength
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 4180

Search results for: fabric strength

2410 Evaluation of Limestone as Self-Curing Aggregate for Concretes in the Southeast of Yucatan Peninsula

Authors: D. G. Rejon-Parra, B. Escobar-Morales, Romeli Barbosa, J. C. Cruz

Abstract:

In the southeast of Yucatan Peninsula, sedimentary limestone has different degrees of compaction. Due to its recent geological formation (Quaternary) and weathering effects causing an affordable aggregate for local manufacturers of concrete. It is characterized as lightweight aggregates (average density of 2,50), susceptible to abrasion and varying porosities (water content exceeding 7,50 % of its mass, in saturated condition). In this study, local aggregates with two moisture conditions (saturated and dry), have been examined in order to compare them for optimizing the performance of concrete. It is possible that these aggregates favour a phenomenon of mass transport (self-curing by porous aggregate); influencing the water reactions to form crystalline and gel hydration products. Based on the ACI methodology, a concrete mixture of 250 kg/cm2 was designed, with portland blended cement 30R. The bond between the mortar and the coarse aggregate was characterized as physicochemical based on trials which were carefully observed during time span of 28 days. The BET technique was used to analyse the micro porosity and surface areas of contact of the different crystalline phases of the limestone. Its chemical composition and crystal structures were verified with scanning electron microscopy SEM-EDS. On the third day, the samples with saturated aggregate reached 237 kg/cm2 of resistence, nearly the design strength; while samples with dry aggregate, exceeded the design strength, with a capacity of 308 kg/cm2. Aggregates in dry conditions demand a high quantity of water in the initial mixture, causing high resistance at the early stages. In saturated conditions, the development of resistance is progressive but constant.

Keywords: concrete, internal curing, limestone aggregate, porosity

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2409 Assessing the Effect of the Position of the Cavities on the Inner Plate of the Steel Shear Wall under Time History Dynamic Analysis

Authors: Masoud Mahdavi, Mojtaba Farzaneh Moghadam

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The seismic forces caused by the waves created in the depths of the earth during the earthquake hit the structure and cause the building to vibrate. Creating large seismic forces will cause low-strength sections in the structure to suffer extensive surface damage. The use of new steel shear walls in steel structures has caused the strength of the building and its main members (columns) to increase due to the reduction and depreciation of seismic forces during earthquakes. In the present study, an attempt was made to evaluate a type of steel shear wall that has regular holes in the inner sheet by modeling the finite element model with Abacus software. The shear wall of the steel plate, measuring 6000 × 3000 mm (one floor) and 3 mm thickness, was modeled with four different pores with a cross-sectional area. The shear wall was dynamically subjected to a time history of 5 seconds by three accelerators, El Centro, Imperial Valley and Kobe. The results showed that increasing the distance between the geometric center of the hole and the geometric center of the inner plate in the steel shear wall (increasing the RCS index) caused the total maximum acceleration to be transferred from the perimeter of the hole to horizontal and vertical beams. The results also show that there is no direct relationship between RCS index and total acceleration in steel shear wall and RCS index is separate from the peak ground acceleration value of earthquake.

Keywords: hollow steel plate shear wall, time history analysis, finite element method, abaqus software

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2408 Remittances and Water Access: A Cross-Sectional Study of Sub Saharan Africa Countries

Authors: Narges Ebadi, Davod Ahmadi, Hiliary Monteith, Hugo Melgar-Quinonez

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Migration cannot necessarily relieve pressure on water resources in origin communities, and male out-migration can increase the water management burden of women. However, inflows of financial remittances seem to offer possibilities of investing in improving drinking-water access. Therefore, remittances may be an important pathway for migrants to support water security. This paper explores the association between water access and the receipt of remittances in households in sub-Saharan Africa. Data from round 6 of the 'Afrobarometer' surveys in 2016 were used (n= 49,137). Descriptive, bivariate and multivariate statistical analyses were carried out in this study. Regardless of country, findings from descriptive analyses showed that approximately 80% of the respondents never received remittance, and 52% had enough clean water. Only one-fifth of the respondents had piped water supply inside the house (19.9%), and approximately 25% had access to a toilet inside the house. Bivariate analyses revealed that even though receiving remittances was significantly associated with water supply, the strength of association was very weak. However, other factors such as the area of residence (rural vs. urban), cash income frequencies, electricity access, and asset ownership were strongly associated with water access. Results from unadjusted multinomial logistic regression revealed that the probability of having no access to piped water increased among remittance recipients who received financial support at least once a month (OR=1.324) (p < 0.001). In contrast, those not receiving remittances were more likely to regularly have a water access concern (OR=1.294) (p < 0.001), and not have access to a latrine (OR=1.665) (p < 0.001). In conclusion, receiving remittances is significantly related to water access as the strength of odds ratios for socio-demographic factors was stronger.

Keywords: remittances, water access, SSA, migration

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2407 Impact of Autoclave Sterilization of Gelatin on Endotoxin Level and Physical Properties Compared to Surfactant Purified Gelatins

Authors: Jos Olijve

Abstract:

Introduction and Purpose: Endotoxins are found in the outer membrane of gram-negative bacteria and have profound in vitro and in vivo responses. They can trigger strong immune responses and negatively affect various cellar activities particular cells expressing toll-like receptors. They are therefore unwanted contaminants of biomaterials sourced from natural raw materials, and their activity must be as low as possible. Collagen and gelatin are natural extracellular matrix components and have, due to their low allergenic potential, suitable biological properties, and tunable physical characteristics, high potential in biomedical applications. The purpose of this study was to determine the influence of autoclave sterilization of gelatin on physical properties and endotoxin level compared to surfactant purified gelatin. Methods: Type A gelatin from Sigma-Aldrich (G1890) with endotoxin level of 35000 endotoxin units (EU) per gram gelatin and type A gelatins from Rousselot Gent with endotoxin activity of 30000 EU per gram were used. A 10 w/w% G1890 gelatin solution was autoclave sterilized during 30 minutes at 121°C and 1 bar over pressure. The physical properties and the endotoxin level of the sterilized G1890 gelatin were compared to a type A gelatin from Rousselot purified with Triton X100 surfactant. The Triton X100 was added to a concentration of 0.5 w/w% which is above the critical micellar concentration. The gelatin surfactant mixtures were kept for 30-45 minutes under constant stirring at 55-60°C. The Triton X100 was removed by active carbon filtration. The endotoxin levels of the gelatins were measured using the Endozyme recombinant factor C method from Hyglos GmbH (Germany). Results and Discussion: Autoclave sterilization significantly affect the physical properties of gelatin. Molecular weight of G1890 decreased from 140 to 50kDa, and gel strength decreased from 300 to 40g. The endotoxin level of the gelatin reduced after sterilization from 35000 EU/g to levels of 400-500 EU/g. These endotoxin levels are however still far above the upper endotoxin level of 0.05 EU/ml, which resembles 5 EU/g gelatin based on a 1% gelatin solution, to avoid cell proliferation alteration. Molecular weight and gel strength of Rousselot gelatin was not altered after Triton X100 purification and remained 150kDa and 300g respectively. The endotoxin levels of Triton X100 purified Rousselot gelatin was < 5EU/g gelatin. Conclusion: Autoclave sterilization of gelatin is, in comparison to Triton X100 purification, not efficient to inactivate endotoxin levels in gelatin to levels below the upper limit to avoid cell proliferation alteration. Autoclave sterilization gave a significant decrease in molecular weight and gel strength which makes autoclave sterilized gelatin, in comparison to Triton X100 purified gelatin, not suitable for 3D printing.

Keywords: endotoxin, gelatin, molecular weight, sterilization, Triton X100

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2406 Study and Analysis of Permeable Articulated Concrete Blocks Pavement: With Reference to Indian Context

Authors: Shrikant Charhate, Gayatri Deshpande

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Permeable pavements have significant benefits like managing runoff, infiltration, and carrying traffic over conventional pavements in terms of sustainability and environmental impact. Some of the countries are using this technique, especially at locations where durability and other parameters are of importance in nature; however, sparse work has been done on this concept. In India, this is yet to be adopted. In this work, the progress in the characterization and development of Permeable Articulated Concrete Blocks (PACB) pavement design is described and discussed with reference to Indian conditions. The experimentation and in-depth analysis was carried out considering conditions like soil erosion, water logging, and dust which are significant challenges caused due to impermeability of pavement. Concrete blocks with size 16.5’’x 6.5’’x 7’’ consisting of arch shape (4’’) at beneath and ½” PVC holes for articulation were casted. These blocks were tested for flexural strength. The articulation process was done with nylon ropes forming series of concrete block system. The total spacing between the blocks was kept about 8 to 10% of total area. The hydraulic testing was carried out by placing the articulated blocks with the combination of layers of soil, geotextile, clean angular aggregate. This was done to see the percentage of seepage through the entire system. The experimental results showed that with the shape of concrete block the flexural strength achieved was beyond the permissible limit. Such blocks with the combination could be very useful innovation in Indian conditions and useful at various locations compared to the traditional blocks as an alternative for long term sustainability.

Keywords: connections, geotextile, permeable ACB, pavements, stone base

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2405 Analysis of Tourism Development Level and Research on Improvement Strategies - Take Chongqing as an Example

Authors: Jiajun Lu, Yun Ma

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As a member of the tertiary industry, tourism is an important driving factor for urban economic development. As a well-known tourist city in China, according to statistics, the added value of tourism and related industries in 2022 will reach 106.326 billion yuan, a year-on-year increase of 1.2%, accounting for 3.7% of the city's GDP. However, the overall tourism development level of Chongqing is seriously unbalanced, and the tourism strength of the main urban area is much higher than that of the southeast Chongqing, northeast Chongqing and the surrounding city tourism area, and the overall tourism strength of the other three regions is relatively balanced. Based on the estimation of tourism development level and the geographic detector method, this paper finds that the important factors affecting the tourism development level of non-main urban areas in Chongqing are A-level tourist attractions. Through GIS geospatial analysis technology and SPSS data correlation research method, the spatial distribution characteristics and influencing factors of A-level tourist attractions in Chongqing were quantitatively analyzed by using data such as geospatial data cloud, relevant documents of Chongqing Municipal Commission of Culture and Tourism Development, planning cloud, and relevant statistical yearbooks. The results show that: (1) The spatial distribution of tourist attractions in non-main urban areas of Chongqing is agglomeration and uneven. (2) The spatial distribution of A-level tourist attractions in non-main urban areas of Chongqing is affected by ecological factors, and the degree of influence is in the order of water factors> topographic factors > green space factors.

Keywords: tourist attractions, geographic detectors, quantitative research, ecological factors, GIS technology, SPSS analysis

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2404 Analysis of the Properties of Hydrophobised Heat-Insulating Mortar with Perlite

Authors: Danuta Barnat-Hunek

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The studies are devoted to assessing the effectiveness of hydrophobic and air entraining admixtures based on organ silicon compounds. Mortars with lightweight aggregate–perlite were the subjects of the investigation. The following laboratory tests were performed: density, open porosity, total porosity, absorptivity, capability to diffuse water vapour, compressive strength, flexural strength, frost resistance, sodium sulphate corrosion resistance and the thermal conductivity coefficient. The composition of the two mixtures of mortars was prepared: mortars without a hydrophobic admixture and mortars with cementitious waterproofing material. Surface hydrophobisation was produced on the mortars without a hydrophobic admixture using a methyl silicone resin, a water-based emulsion of methyl silicone resin in potassium hydroxide and alkyl-alkoxy-silane in organic solvents. The results of the effectiveness of hydrophobisation of mortars are the following: The highest absorption after 14 days of testing was shown by mortar without an agent (57.5%), while the lowest absorption was demonstrated by the mortar with methyl silicone resin (52.7%). After 14 days in water the hydrophobisation treatment of the samples proved to be ineffective. The hydrophobised mortars are characterized by an insignificant mass change due to freezing and thawing processes in the case of the methyl silicone resin – 1%, samples without hydrophobisation –5%. This agent efficiently protected the mortars against frost corrosion. The standard samples showed very good resistance to the pressure of sodium sulphate crystallization. Organosilicon compounds have a negative influence on the chemical resistance (weight loss about 7%). The mass loss of non-hydrophobic mortar was 2 times lower than mortar with the hydrophobic admixture. Hydrophobic and aeration admixtures significantly affect the thermal conductivity and the difference is mainly due to the difference in porosity of the compared materials. Hydrophobisation of the mortar mass slightly decreased the porosity of the mortar, and thus in an increase of 20% of its compressive strength. The admixture adversely affected the ability of the hydrophobic mortar – it achieved the opposite effect. As a result of hydrophobising the mass, the mortar samples decreased in density and had improved wettability. Poor protection of the mortar surface is probably due to the short time of saturating the sample in the preparation. The mortars were characterized by high porosity (65%) and water absorption (57.5%), so in order to achieve better efficiency, extending the time of hydrophobisation would be advisable. The highest efficiency was obtained for the surface hydrophobised with the methyl silicone resin.

Keywords: hydrophobisation, mortars, salt crystallization, frost resistance

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2403 Efficiency of Visible Light Induced Photocatalytic Oxidation of Toluene and Benzene by a Photocatalytic Textile

Authors: Z. Younsi, L. Koufi, H. Gidik, D. Lahem, W. Wim Thielemans

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This study investigated the efficiency of photocatalytic textile to remove the Volatile Organic Compounds (VOCs) present in indoor air. Functionalization of the fabric was achieved by adding a photocatalyst material active in the visible spectrum of light. This is a modified titanium dioxide photocatalyst doped with non-metal ions synthesized via sol-gel process, which should allow the degradation of the pollutants – ideally into H₂O and CO₂ – using photocatalysis based on visible light and no additionnal external energy source. The visible light photocatalytic activity of textile sample was evaluated for toluene and benzene gaseous removal, under the visible irradiation, in a test chamber with the total volume of 1m³. The suggested approach involves experimental investigations of the global behavior of the photocatalytic textile. The experimental apparatus permits simultaneous measurements of the degradation of pollutants and presence of eventually formed by-products. It also allows imposing and measuring concentration variations with respect to selected time scales in the test chamber. The observed results showed that the amount of TiO₂ incorporation improved the photocatalytic efficiency of functionalized textile significantly under visible light. The results obtained with such textile are very promising.

Keywords: benzene, C₆H₆, efficiency, photocatalytic degradation, textile fabrics, titanium dioxide, TiO₂, toluene, C₇H₈, visible light

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2402 Effect of Whey Protein-Rice Bran Oil Incorporated Zataria multiflora Extract Edible Coating on Chemical, Physical and Microbial Quality of Chicken Egg

Authors: Majid Javanmard

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In this study, the effects of coating with whey protein concentrate (7.5% w/v) alone and/or in combination with rice bran oil (0.2, 0.4, 0.6 g in 100 ml coating solution) and Zataria multiflora extract (1 and 2 μL in 100 ml coating solution) on the quality attributes and egg shelf life were carefully observed and analyzed. Weight loss, Haugh index, yolk index, pH, air cell depth, shell strength and the impact of this coating on the microbial load of the eggs surface were studied at the end of each week (during the 4 weeks of storage in a room environment temperature and humidity). After 4 weeks of storage, it was observed that the weight loss in all of the treated eggs with whey protein concentrate and 0.2 gr of rice bran oil (experimental group) was significantly lower than that of the control group(P < 0/05). With regard to Haugh index and yolk index, egg shelf life increased about 4 weeks compared with the control samples. Haugh Index changes revealed that the coated samples remained at grade A after 3 weeks of storage, while the control samples were relegated from grade AA to B after one week. Haugh and yolk Indices in all coated eggs were more than those of the control group. In the coated groups, Haugh and yolk indices of the coated samples with whey protein concentrate and 0.2 g rice bran oil and with whey protein concentrate and 0.2g of rice bran oil and 1 micro liter of Zataria multiflora extract were more than those of the other coated eggs and the control group eggs. PH values of the control group were higher than those of the coated groups during the storage of the eggs. The shell strength of the coated group was more than that of the control group (uncoated) and in coated samples, whey protein concentrate and 0.2 gr of rice bran oil coated samples had high shell strength. In the other treatments, no significant differences were observed. The depth of the air cell of the coated groups was determined to be less than that of the control group during the storage period. The minimum inhibitory concentration was 1 μL of Zataria multiflora extract. The results showed that 1 μL concentration of Zataria multiflora extract reduces the microbial load of the egg shell surface to 87% and 2 μL reduced total bacterial load to zero. In sensory evaluation, from evaluator point of view, the coated eggs had more overall acceptance than the uncoated group (control), and in the treatment group coated eggs, those containing a low percentage of rice bran oil had higher overall acceptability. In conclusion, coating as a practical and cost effective method can maintain the quality parameters of eggs and lead to durability of supply conditions in addition to the product marketability.

Keywords: edible coating, chicken egg, whey protein concentrate, rice bran oil, Zataria multiflora extract, shelf life

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2401 The Influence of Size on Fused Silica Strength: A Multi-Method Study

Authors: Şeyma Saliha Fidan, Rahmi Ünal

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Ceramic materials exhibit inherently brittle behavior, primarily attributed to the presence of flaws that severely restrict their applicability as structural elements under tensile loading. This brittleness necessitates special attention in the design of ceramic components, with a particular focus on appropriately addressing stress distribution. Among the most commonly used uniaxial testing methods to evaluate the mechanical behavior of ceramics are three-point bending and four-point bending tests. Each of these methods induces a unique stress distribution within the specimen. Using Weibull theory and its fundamental assumptions, it is possible to account for the different stress fields produced by each testing method and compare the resulting strength data. This comparison is based on the concept of effective volume or area. In this study, slip-cast fused silica ceramics were selected as the material of interest. The study aims to apply Weibull statistical theory to various testing methods, integrating statistical tools and finite element method (FEM) simulations. A validated FEM-based approach was developed to determine the effective volumes of the specimens. The effective volume values obtained through analytical and numerical methods were compared, and the stress fields generated by different testing methods were evaluated based on Weibull theory. Moreover, the effective volume calculation procedure derived from numerical analysis methods has been adapted for use in complex test geometries and various loading conditions.

Keywords: ceramic, fused silica, effective volume, Weibull analysis, finite element method

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2400 A Design Approach in Architectural Education: Parasitic Architecture

Authors: Ozlem Senyigit, Nur Yilmaz

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Throughout the architectural education, it is aimed to provide students with the ability to find original solutions to current problems. In this sense, workshops that provide creative thinking within the action, experiencing the environment, and finding instant solutions to problems have an important place in the education process. Parasitic architecture, which is a contemporary design approach in the architectural agenda, includes small scale designs integrated into the carrier system of existing structures in spaces of the existing urban fabric which resembles the host-parasite relationship in the biology field. The scope of this study consists of a 12-weeks long experimental workshop of the 'parasitic architecture', which was designed within the scope of Basic Design 2 course of the Department of Architecture of Çukurova University in the 2017-2018 academic year. In this study, parasitic architecture was discussed as a space design method. Students analyzed the campus of the Çukurova University and drew sketches to identify gaps in it. During the workshop, the function-form-context relationship was discussed. The output products were evaluated within the context of urban spaces/gaps, functional requirements, and students gained awareness not just about the urban occupancy but also gaps.

Keywords: design approach, parasitic architecture, experimental workshop, architectural education

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2399 Effect of Resistance Exercise on Hypothalamic-Pituitary-Gonadal Axis

Authors: Alireza Barari, Saeed Shirali, Ahmad Abdi

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Abstract: Introduction: Physical activity may be related to male reproductive function by affecting on thehypothalamic-pituitary-gonadal(HPG) axis. Our aim was to determine the effects of 6 weeks resistance exercise on reproductive hormones, HPG axis. The hypothalamic-pituitary-gonadal (HPG) axis refers tothe effects of endocrine glands in three-level including (i) the hypothalamic releasing hormone GnRH, which is synthesized in in a small heterogenous neuronal population and released in a pulsatile fashion, (ii) the anterior pituitary hormones, follicle-stimulating hormone(FSH) and luteinizing hormone (LH) and (iii) the gonadal hormones, which include both steroid such as testosterone (T), estradiol and progesterone and peptide hormones (such as inhibin). Hormonal changes that create a more anabolic environment have been suggested to contribute to the adaptation to strength exercise. Physical activity has an extensive impact on male reproductive function depending upon the intensity and duration of the exercise and the fitness level of the individual. However, strenuous exercise represents a physical stress and inflammation changed that challenges homeostasis. Materials and methods: Sixteen male volunteered were included in a 6-week control period followed by 6 weeks of resistance training (leg press, lat pull, chest press, squat, seatedrow, abdominal crunch, shoulder press, biceps curl and triceps press down) four times per week. intensity of training loading was 60%-75% of one maximum repetition. Participants performed 3 sets of 10 repetitions. Rest periods were two min between exercises and sets. Start with warm up exercises include: The muscles relax and stretch the body, which was for 10 minutes. Body composition, VO2max and the circulating level of free testosterone (fT), luteinizing hormone (LH), follicle-stimulating hormone (FSH), sex hormone binding globulin (SHBG) and inhibin B measured prior and post 6-week intervention. The hormonal levels of each serum sample were measured using commercially available ELISA kits. Analysis of anthropometrical data and hormonal level were compared using the independent samples t- test in both groups and using SPSS (version 19). P ≤ 0.05 was considered statistically significant. Results: For muscle strength, both lower- and upper-body strength were increased significantly. Aerobic fitness level improved in trained participant from 39.4 ± 5.6 to 41.9 ± 5.3 (P = 0.002). fT concentration rise progressively in the trained group and was significantly greater than those in the control group (P = 0.000). By the end of the 6-week resistance training, serum SHBG significantly increased in the trained group compared with the control group (P = 0.013). In response to resistance training, LH, FSH and inhibin B were not significantly changed. Discussion: According to our finfings, 6 weeks of resistance training induce fat loss without any changes in body weight and BMI. A decline of 25.3% in percentage of body fat with statiscally same weight was due to increase in muscle mass that happened during resistance exercise periods . Six weeks of resistance training resulted in significant improvement in BF%, VO2max and increasing strength and the level of fT and SHBG.

Keywords: resistance, hypothalamic, pituitary, gonadal axis

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2398 E-Commerce Implementation to Support Customize Clothes for Obese People

Authors: Hamza Al-Hazmi, Tabrej Khan

Abstract:

Obesity is today a global phenomenon that affects all countries, all types of societies regardless of age, sex, and income. The average value of the relative body mass index (BMI) has increased, which indicates an increasing obesity problem in the population. Nowadays obesity is a global problem, and mass production of clothes is standard size. People have a problem to find best-fitted clothes. The goal of the project is to develop an E-Commerce web portal as a new, innovative and customize clothing production system for obese people. This research has a long-term objective and short-term objective. The long-term objectives are (1) utilize online Web portal to improve tailors’ income, and (2) provide a free online platform to the tailors and customers in order to stitch clothes. Then, the short-term objective are (1) identify e-commerce’s requirements, (2) analyze and design the e-commerce application, and (3) build and implement the e-commerce application to Customized Clothes for Overweight people. This application can hopefully improve the tailors’ income and provide an easy way for customers to choose a fabric, apply style and provide measurement. This e-commerce application is not limited to obese or overweight people but also for other people who want to stitch cloth from tailors. MySQL and PHP we are going to use for developing the application.

Keywords: e-commerce, obesity, PHP, customize clothes

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2397 Determination of the Thermophysical Characteristics of the Composite Material Clay Cement Paper

Authors: A. Ouargui, N. Belouaggadia, M. Ezzine

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In Morocco, the building sector is largely responsible for the evolution of energy consumption. The control of energy in this sector remains a major issue despite the rise of renewable energies. The design of an environmentally friendly building requires mastery and knowledge of energy and bioclimatic aspects. This implies taking into consideration of all the elements making up the building and the way in which energy exchanges take place between these elements. In this context, thermal insulation seems to be an ideal starting point for reducing energy consumption and greenhouse gas emissions. In this context, thermal insulation seems to be an ideal starting point for reducing energy consumption and greenhouse gas emissions. The aim of this work is to provide some solutions to reduce energy consumption while maintaining thermal comfort in the building. The objective of our work is to present an experimental study on the characterization of local materials used in the thermal insulation of buildings. These are paper recycling stabilized with cement and clay. The thermal conductivity of these materials, which were constituted based on sand, clay, cement; water, as well as treated paper, was determined by the guarded-hot-plate method. It involves the design of two materials that will subsequently be subjected to thermal and mechanical tests to determine their thermophysical properties. The results show that the thermal conductivity decreases as well in the case of the paper-cement mixture as that of the paper-clay and seems to stabilize around 40%. Measurements of mechanical properties such as flexural strength have shown that the enrichment of the studied material with paper makes it possible to reduce the flexural strength by 20% while optimizing the conductivity.

Keywords: building, composite material, insulation, thermal conductivity, paper residue

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2396 Effect of Cryogenic Treatment on Hybrid Natural Fiber Reinforced Polymer Composites

Authors: B. Vinod, L. J. Sudev

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Natural fibers as reinforcement in polymer matrix material are gaining lot of attention in recent years. Natural fibers like jute, sisal, coir, hemp, banana etc. have attracted substantial importance as a potential structural material because of its attractive features along with its good mechanical properties. Cryogenic applications of natural fiber reinforced polymer composites are gaining importance. These materials need to possess good mechanical and physical properties at cryogenic temperatures to meet the high requirements by the cryogenic engineering applications. The objective of this work is to investigate the mechanical behavior of hybrid hemp/jute fibers reinforced epoxy composite material at liquid nitrogen temperature. Hybrid hemp/jute fibers reinforced polymer composite is prepared by hand lay-up method and test specimens are cut according to ASTM standards. These test specimens are dipped in liquid nitrogen for different time durations. The tensile properties, flexural properties and impact strength of the specimen are tested immediately after the specimens are removed from liquid nitrogen container. The experimental results indicate that the cryogenic treatment of the polymer composite has a significant effect on the mechanical properties of this material. The tensile properties and flexural properties of the hybrid hemp/jute fibers epoxy composite at liquid nitrogen temperature is higher than at room temperature. The impact strength of the material decreased after subjecting it to liquid nitrogen temperature.

Keywords: liquid nitrogen temperature, polymer composite, tensile properties, flexural properties

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2395 Evaluation of Invasive Tree Species for Production of Phosphate Bonded Composites

Authors: Stephen Osakue Amiandamhen, Schwaller Andreas, Martina Meincken, Luvuyo Tyhoda

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Invasive alien tree species are currently being cleared in South Africa as a result of the forest and water imbalances. These species grow wildly constituting about 40% of total forest area. They compete with the ecosystem for natural resources and are considered as ecosystem engineers by rapidly changing disturbance regimes. As such, they are harvested for commercial uses but much of it is wasted because of their form and structure. The waste is being sold to local communities as fuel wood. These species can be considered as potential feedstock for the production of phosphate bonded composites. The presence of bark in wood-based composites leads to undesirable properties, and debarking as an option can be cost implicative. This study investigates the potentials of these invasive species processed without debarking on some fundamental properties of wood-based panels. Some invasive alien tree species were collected from EC Biomass, Port Elizabeth, South Africa. They include Acacia mearnsii (Black wattle), A. longifolia (Long-leaved wattle), A. cyclops (Red-eyed wattle), A. saligna (Golden-wreath wattle) and Eucalyptus globulus (Blue gum). The logs were chipped as received. The chips were hammer-milled and screened through a 1 mm sieve. The wood particles were conditioned and the quantity of bark in the wood was determined. The binding matrix was prepared using a reactive magnesia, phosphoric acid and class S fly ash. The materials were mixed and poured into a metallic mould. The composite within the mould was compressed at room temperature at a pressure of 200 KPa. After initial setting which took about 5 minutes, the composite board was demoulded and air-cured for 72 h. The cured product was thereafter conditioned at 20°C and 70% relative humidity for 48 h. Test of physical and strength properties were conducted on the composite boards. The effect of binder formulation and fly ash content on the properties of the boards was studied using fitted response surface technology, according to a central composite experimental design (CCD) at a fixed wood loading of 75% (w/w) of total inorganic contents. The results showed that phosphate/magnesia ratio of 3:1 and fly ash content of 10% was required to obtain a product of good properties and sufficient strength for intended applications. The proposed products can be used for ceilings, partitioning and insulating wall panels.

Keywords: invasive alien tree species, phosphate bonded composites, physical properties, strength

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2394 Effect of Pre-bonding Storage Period on Laser-treated Al Surfaces

Authors: Rio Hirakawa, Christian Gundlach, Sven Hartwig

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In recent years, the use of aluminium has further expanded and is expected to replace steel in the future as vehicles become lighter and more recyclable in order to reduce greenhouse gas (GHG) emissions and improve fuel economy. In line with this, structures and components are becoming increasingly multi-material, with different materials, including aluminium, being used in combination to improve mechanical utility and performance. A common method of assembling dissimilar materials is mechanical fastening, but it has several drawbacks, such as increased manufacturing processes and the influence of substrate-specific mechanical properties. Adhesive bonding and fusion bonding are methods that overcome the above disadvantages. In these two joining methods, surface pre-treatment of the substrate is always necessary to ensure the strength and durability of the joint. Previous studies have shown that laser surface treatment improves the strength and durability of the joint. Yan et al. showed that laser surface treatment of aluminium alloys changes α-Al2O3 in the oxide layer to γ-Al2O3. As γ-Al2O3 has a large specific surface area, is very porous and chemically active, laser-treated aluminium surfaces are expected to undergo physico-chemical changes over time and adsorb moisture and organic substances from the air or storage atmosphere. The impurities accumulated on the laser-treated surface may be released at the adhesive and bonding interface by the heat input to the bonding system during the joining phase, affecting the strength and durability of the joint. However, only a few studies have discussed the effect of such storage periods on laser-treated surfaces. This paper, therefore, investigates the ageing of laser-treated aluminium alloy surfaces through thermal analysis, electrochemical analysis and microstructural observations.AlMg3 of 0.5 mm and 1.5 mm thickness was cut using a water-jet cutting machine, cleaned and degreased with isopropanol and surface pre-treated with a pulsed fibre laser at 1060 nm wavelength, 70 W maximum power and 55 kHz repetition frequency. The aluminium surface was then analysed using SEM, thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR) and cyclic voltammetry (CV) after storage in air for various periods ranging from one day to several months TGA and FTIR analysed impurities adsorbed on the aluminium surface, while CV revealed changes in the true electrochemically active surface area. SEM also revealed visual changes on the treated surface. In summary, the changes in the laser-treated aluminium surface with storage time were investigated, and the final results were used to determine the appropriate storage period.

Keywords: laser surface treatment, pre-treatment, adhesion, bonding, corrosion, durability, dissimilar material interface, automotive, aluminium alloys

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2393 Benefits of PRP in Third Molar Surgery - A Review of the Literature

Authors: Nitesh Kumar, Adel Elrasheed, Antonio Gagliardilugo

Abstract:

Introduction and aims: PRP has been increasing in popularity over the past decade. It is used in many facets of medicine and dentistry such as osteoarthritis, hair loss, skin rejunavation, healing of tendons after injury. Due to the increasing popularity of PRP in third molar surgery in dentistry, this study aims to identify the role of platelet rich plasma and its function in third molar surgery. Methodology: Three databases were chosen to source the articles for review: pubmed, science direct, and Cochrane. The keywords “platelet rich plasma”, “third molar extraction” and “wisdom tooth extraction” and literature review were used to search for relevant articles. Articles that were not in English were omitted and only systematic reviews relevant to the study were collected. All systematic reviews abstracts pertinent to the study were read by two reviewers to avoid bias. Results/statistics: 20 review articles were obtained of which 13 fulfilled the criteria. The Amstar tool validified the strength of these review articles. There is strong evidence in the literature that PRP in third molar surgery decreases post op pain, swelling and recovery time. 20 review articles were obtained of which 13 fulfilled the criteria. The Amstar tool validified the strength of these review articles. There is strong evidence in the literature that PRP in third molar surgery decreases post op pain, swelling and recovery time. Conclusions/clinical relevance: Platelet rich plasma plays a crucial role in patient recovery following the extraction of third molars and should be considered and offered as a routine part of third molar therapy.

Keywords: PRP, third molar, extractions, wisdom teeth

Procedia PDF Downloads 62
2392 Customer Preference in the Textile Market: Fabric-Based Analysis

Authors: Francisca Margarita Ocran

Abstract:

Underwear, and more particularly bras and panties, are defined as intimate clothing. Strictly speaking, they enhance the place of women in the public or private satchel. Therefore, women's lingerie is a complex garment with a high involvement profile, motivating consumers to buy it not only by its functional utility but also by the multisensory experience it provides them. Customer behavior models are generally based on customer data mining, and each model is designed to answer questions at a specific time. Predicting the customer experience is uncertain and difficult. Thus, knowledge of consumers' tastes in lingerie deserves to be treated as an experiential product, where the dimensions of the experience motivating consumers to buy a lingerie product and to remain faithful to it must be analyzed in detail by the manufacturers and retailers to engage and retain consumers, which is why this research aims to identify the variables that push consumers to choose their lingerie product, based on an in-depth analysis of the types of fabrics used to make lingerie. The data used in this study comes from online purchases. Machine learning approach with the use of Python programming language and Pycaret gives us a precision of 86.34%, 85.98%, and 84.55% for the three algorithms to use concerning the preference of a buyer in front of a range of lingerie. Gradient Boosting, random forest, and K Neighbors were used in this study; they are very promising and rich in the classification of preference in the textile industry.

Keywords: consumer behavior, data mining, lingerie, machine learning, preference

Procedia PDF Downloads 92
2391 Wellbeing Warriors: A Randomized Controlled Trial Examining the Effect of Martial Arts Training on Mental Health Outcomes

Authors: Brian Moore, Stuart Woodcock, Dean Dudley

Abstract:

Mental health problems have significant social and economic consequences; however, many individuals do not seek traditional assistance for mental health difficulties. Martial arts training may provide an inexpensive alternative to traditional psychological therapy. While limited research has suggested martial arts training may be an efficacious intervention, the validity and reliability of this are questionable given the small number of relevant studies and other methodological problems. The study examined the effects of 10-week martial arts-based psycho-social intervention which was evaluated using a randomized controlled trial. The intervention was delivered to 283 secondary school students, aged between 12-14 years, who were recruited from government and catholic secondary schools in New South Wales, Australia. The intervention was delivered in a group format onsite at participating schools and had an intervention dose of 10 x 50-60 minute sessions, once per week for 10 weeks. Data were collected at baseline, post-intervention, and 12-week follow-up. Results found a consistent pattern for strength based wellbeing outcomes. All primary and secondary measures relating to resilience and self-efficacy improved for the intervention group and declined for the control group. As these findings were derived from a robust design and rigorous evaluation, they provide valid and reliable evidence that martial arts-based psycho-social interventions can be considered as an efficacious method of improving strength and wellbeing outcomes.

Keywords: martial arts, mental health, resilience, self-efficacy

Procedia PDF Downloads 162
2390 Drilling Quantification and Bioactivity of Machinable Hydroxyapatite : Yttrium phosphate Bioceramic Composite

Authors: Rupita Ghosh, Ritwik Sarkar, Sumit K. Pal, Soumitra Paul

Abstract:

The use of Hydroxyapatite bioceramics as restorative implants is widely known. These materials can be manufactured by pressing and sintering route to a particular shape. However machining processes are still a basic requirement to give a near net shape to those implants for ensuring dimensional and geometrical accuracy. In this context, optimising the machining parameters is an important factor to understand the machinability of the materials and to reduce the production cost. In the present study a method has been optimized to produce true particulate drilled composite of Hydroxyapatite Yttrium Phosphate. The phosphates are used in varying ratio for a comparative study on the effect of flexural strength, hardness, machining (drilling) parameters and bioactivity.. The maximum flexural strength and hardness of the composite that could be attained are 46.07 MPa and 1.02 GPa respectively. Drilling is done with a conventional radial drilling machine aided with dynamometer with high speed steel (HSS) and solid carbide (SC) drills. The effect of variation in drilling parameters (cutting speed and feed), cutting tool, batch composition on torque, thrust force and tool wear are studied. It is observed that the thrust force and torque varies greatly with the increase in the speed, feed and yttrium phosphate content in the composite. Significant differences in the thrust and torque are noticed due to the change of the drills as well. Bioactivity study is done in simulated body fluid (SBF) upto 28 days. The growth of the bone like apatite has become denser with the increase in the number of days for all the composition of the composites and it is comparable to that of the pure hydroxyapatite.

Keywords: Bioactivity, Drilling, Hydroxyapatite, Yttrium Phosphate

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2389 Combined Effect of Heat Stimulation and Delayed Addition of Superplasticizer with Slag on Fresh and Hardened Property of Mortar

Authors: Faraidoon Rahmanzai, Mizuki Takigawa, Yu Bomura, Shigeyuki Date

Abstract:

To obtain the high quality and essential workability of mortar, different types of superplasticizers are used. The superplasticizers are the chemical admixture used in the mix to improve the fluidity of mortar. Many factors influenced the superplasticizer to disperse the cement particle in the mortar. Nature and amount of replaced cement by slag, mixing procedure, delayed addition time, and heat stimulation technique of superplasticizer cause the varied effect on the fluidity of the cementitious material. In this experiment, the superplasticizers were heated for 1 hour under 60 °C in a thermostatic chamber. Furthermore, the effect of delayed addition time of heat stimulated superplasticizers (SP) was also analyzed. This method was applied to two types of polycarboxylic acid based ether SP (precast type superplasticizer (SP2) and ready-mix type superplasticizer (SP1)) in combination with a partial replacement of normal Portland cement with blast furnace slag (BFS) with 30% w/c ratio. On the other hands, the fluidity, air content, fresh density, and compressive strength for 7 and 28 days were studied. The results indicate that the addition time and heat stimulation technique improved the flow and air content, decreased the density, and slightly decreased the compressive strength of mortar. Moreover, the slag improved the flow of mortar by increasing the amount of slag, and the effect of external temperature of SP on the flow of mortar was decreased. In comparison, the flow of mortar was improved on 5-minute delay for both kinds of SP, but SP1 has improved the flow in all conditions. Most importantly, the transition points in both types of SP appear to be the same, at about 5±1 min.  In addition, the optimum addition time of SP to mortar should be in this period.

Keywords: combined effect, delay addition, heat stimulation, flow of mortar

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2388 Fabrication of Nanoengineered Radiation Shielding Multifunctional Polymeric Sandwich Composites

Authors: Nasim Abuali Galehdari, Venkat Mani, Ajit D. Kelkar

Abstract:

Space Radiation has become one of the major factors in successful long duration space exploration. Exposure to space radiation not only can affect the health of astronauts but also can disrupt or damage materials and electronics. Hazards to materials include degradation of properties, such as, modulus, strength, or glass transition temperature. Electronics may experience single event effects, gate rupture, burnout of field effect transistors and noise. Presently aluminum is the major component in most of the space structures due to its lightweight and good structural properties. However, aluminum is ineffective at blocking space radiation. Therefore, most of the past research involved studying at polymers which contain large amounts of hydrogen. Again, these materials are not structural materials and would require large amounts of material to achieve the structural properties needed. One of the materials to alleviate this problem is polymeric composite materials, which has good structural properties and use polymers that contained large amounts of hydrogen. This paper presents steps involved in fabrication of multi-functional hybrid sandwich panels that can provide beneficial radiation shielding as well as structural strength. Multifunctional hybrid sandwich panels were manufactured using vacuum assisted resin transfer molding process and were subjected to radiation treatment. Study indicates that various nanoparticles including Boron Nano powder, Boron Carbide and Gadolinium nanoparticles can be successfully used to block the space radiation without sacrificing the structural integrity.

Keywords: multi-functional, polymer composites, radiation shielding, sandwich composites

Procedia PDF Downloads 286
2387 Breaking Stress Criterion that Changes Everything We Know About Materials Failure

Authors: Ali Nour El Hajj

Abstract:

Background: The perennial deficiencies of the failure models in the materials field have profoundly and significantly impacted all associated technical fields that depend on accurate failure predictions. Many preeminent and well-known scientists from an earlier era of groundbreaking discoveries attempted to solve the issue of material failure. However, a thorough understanding of material failure has been frustratingly elusive. Objective: The heart of this study is the presentation of a methodology that identifies a newly derived one-parameter criterion as the only general failure theory for noncompressible, homogeneous, and isotropic materials subjected to multiaxial states of stress and various boundary conditions, providing the solution to this longstanding problem. This theory is the counterpart and companion piece to the theory of elasticity and is in a formalism that is suitable for broad application. Methods: Utilizing advanced finite-element analysis, the maximum internal breaking stress corresponding to the maximum applied external force is identified as a unified and universal material failure criterion for determining the structural capacity of any system, regardless of its geometry or architecture. Results: A comparison between the proposed criterion and methodology against design codes reveals that current provisions may underestimate the structural capacity by 2.17 times or overestimate the capacity by 2.096 times. It also shows that existing standards may underestimate the structural capacity by 1.4 times or overestimate the capacity by 2.49 times. Conclusion: The proposed failure criterion and methodology will pave the way for a new era in designing unconventional structural systems composed of unconventional materials.

Keywords: failure criteria, strength theory, failure mechanics, materials mechanics, rock mechanics, concrete strength, finite-element analysis, mechanical engineering, aeronautical engineering, civil engineering

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2386 Leveraging Hyperledger Iroha for the Issuance and Verification of Higher-Education Certificates

Authors: Vasiliki Vlachou, Christos Kontzinos, Ourania Markaki, Panagiotis Kokkinakos, Vagelis Karakolis, John Psarras

Abstract:

Higher Education is resisting the pull of technology, especially as this concerns the issuance and verification of degrees and certificates. It is widely known that education certificates are largely produced in paper form making them vulnerable to damage while holders of such certificates are dependent on the universities and other issuing organisations. QualiChain is an EU Horizon 2020 (H2020) research project aiming to transform and revolutionise the domain of public education and its ties with the job market by leveraging blockchain, analytics and decision support to develop a platform for the verification and sharing of education certificates. Blockchain plays an integral part in the QualiChain solution in providing a trustworthy environment to store, share and manage such accreditations. Under the context of this paper, three prominent blockchain platforms (Ethereum, Hyperledger Fabric, Hyperledger Iroha) were considered as a means of experimentation for creating a system with the basic functionalities that will be needed for trustworthy degree verification. The methodology and respective system developed and presented in this paper used Hyperledger Iroha and proved that this specific platform can be used to easily develop decentralize applications. Future papers will attempt to further experiment with other blockchain platforms and assess which has the best potential.

Keywords: blockchain, degree verification, higher education certificates, Hyperledger Iroha

Procedia PDF Downloads 142
2385 Ingenious Use of Hypo Sludge in M25 Concrete

Authors: Abhinandan Singh Gill

Abstract:

Paper mill sludge is one of the major economic and environmental problems for paper and board industry, million tonnes quantity of sludge is produced in the world. It is essential to dispose these wastes safely without affecting health of human being, environment, fertile land; sources of water bodies, economy as it adversely affect the strength, durability and other properties of building materials based on them. Moreover, in developing countries like India where there is low availability of non-renewable resources and large need of building material like cement therefore it is essential to develop eco-efficient utilization of paper sludge. Primarily in functional terms paper sludge comprises of cellulose fibers, calcium carbonate, china clay, low silica, residual chemical bonds with water. The material is sticky and full of moisture content which is hard to dry. The manufacturing of paper usually produce loads of solid waste. These paper fibers are recycled in paper mills to limited number of times till they become weak to produce high quality paper. Thereafter, these left out small and weak pieces called as low quality paper fibers are detached out to become paper sludge. The material is by-product of de-inking and re-pulping of paper. This hypo sludge includes all kinds of inks, dyes, coating etc inscribed on the paper. This paper presents an overview of the published work on the use of hypo sludge in M25 concrete formulations as a supplementary cementitious material exploring its properties such as compressive strength, splitting and parameters like modulus of elasticity, density, applications and most importantly investigation of low cost concrete by using hypo sludge are presented.

Keywords: concrete, sludge waste, hypo sludge, supplementary cementitious material

Procedia PDF Downloads 310
2384 ACL Tear Prevention Program

Authors: Ervin Meqikukiqi

Abstract:

It is difficult to assess how athletes can best modify their movements to prevent non contact ACL injuries. Speaking with an athletic trainer, physical therapist, or sports medicine specialist is a good place to start. Recent research has allowed therapists and clinicians to easily identify and target weak muscle areas (e.g., weak hips, which leads to knock-kneed landing positions) and identify ways to improve strength and thus help prevent injury. In addition, other risk factors such as reduced hamstring strength and increased joint range of motion can be further assessed by a physical therapist or athletic trainer to improve performance-or rehabilitation efforts after an injury has occurred. Current studies also demonstrate that specific types of training, such as jump routines and learning to pivot properly, help athletes prevent ACL injuries. These types of exercises and training programs are more beneficial if athletes start when they are young. It may be optimal to integrate prevention programs during early adolescence, prior to when young athletes develop certain habits that increase the risk of an ACL injury. This is a 20 minute program designed to reduce the risk of tears of the Anterior Cruciate Ligament. It should be started at least four and preferably six weeks prior to start of competition.Ideally it is done five times per week preseason and three times per week in season.The coach or trainer must constantly observe athletes during these exercises to correct and maintain proper technique. Once the athletes understand the principles, they can monitor and coach each other. Four phases: Warm-up, Strengthening, Plyometrics, Agility and Balance.

Keywords: athletes, acl, prevention, injuries, plyoemtric, proprioception, agillity

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2383 Reliability of Dissimilar Metal Soldered Joint in Fabrication of Electromagnetic Interference Shielded Door Frame

Authors: Rehan Waheed, Hasan Aftab Saeed, Wasim Tarar, Khalid Mahmood, Sajid Ullah Butt

Abstract:

Electromagnetic Interference (EMI) shielded doors made from brass extruded channels need to be welded with shielded enclosures to attain optimum shielding performance. Control of welding induced distortion is a problem in welding dissimilar metals like steel and brass. In this research, soldering of the steel-brass joint has been proposed to avoid weld distortion. The material used for brass channel is UNS C36000. The thickness of brass is defined by the manufacturing process, i.e. extrusion. The thickness of shielded enclosure material (ASTM A36) can be varied to produce joint between the dissimilar metals. Steel sections of different gauges are soldered using (91% tin, 9% zinc) solder to the brass, and strength of joint is measured by standard test procedures. It is observed that thin steel sheets produce a stronger bond with brass. The steel sections further require to be welded with shielded enclosure steel sheets through TIG welding process. Stresses and deformation in the vicinity of soldered portion is calculated through FE simulation. Crack formation in soldered area is also studied through experimental work. It has been found that in thin sheets deformation produced due to applied force is localized and has no effect on soldered joint area whereas in thick sheets profound cracks have been observed in soldered joint. The shielding effectiveness of EMI shielded door is compromised due to these cracks. The shielding effectiveness of the specimens is tested and results are compared.

Keywords: dissimilar metal, EMI shielding, joint strength, soldering

Procedia PDF Downloads 164
2382 Microscopic and Mesoscopic Deformation Behaviors of Mg-2Gd Alloy with or without Li Addition

Authors: Jing Li, Li Jin, Fulin Wang, Jie Dong, Wenjiang Ding

Abstract:

Mg-Li dual-phase alloy exhibits better combination of yield strength and elongation than the Mg single-phase alloy. To exploit its deformation behavior, the deformation mechanisms of Mg-2Gd alloy with or without Li addition, i.e., Mg-6Li-2Gd and Mg-2Gd alloy, have been studied at both microscale and mesoscale. EBSD-assisted slip trace, twin trace, and texture evolution analysis show that the α-Mg phase of Mg-6Li-2Gd alloy exhibits different microscopic deformation mechanisms with the Mg-2Gd alloy, i.e., mainly prismatic slip in the former one, while basal slip, prismatic slip and extension twin in the latter one. Further Schmid factor analysis results attribute this different intra-phase deformation mechanisms to the higher critical resolved shear stress (CRSS) value of extension twin and lower ratio of CRSSprismatic /CRSSbasal in the α-Mg phase of Mg-6Li-2Gd alloy. Additionally, Li addition can induce dual-phase microstructure in the Mg-6Li-2Gd alloy, leading to the formation of hetero-deformation induced (HDI) stress at the mesoscale. This can be evidenced by the hysteresis loops appearing during the loading-unloading-reloading (LUR) tensile tests and the activation of multiple slip activity in the α-Mg phase neighboring β-Li phase. The Mg-6Li-2Gd alloy shows higher yield strength is due to the harder α-Mg phase arising from solid solution hardening of Li addition, as well asthe strengthening of soft β-Li phase by the HDI stress during yield stage. Since the strain hardening rate of Mg-6Li-2Gd alloy is lower than that of Mg-2Gd alloy after ~2% strain, which is partly due to the weak contribution of HDI stress, Mg-6Li-2Gd alloy shows no obvious increase of uniform elongation than the Mg-2Gd alloy.But since the β-Li phase is effective in blunting the crack tips, the Mg-6Li-2Gd alloy shows ununiform elongation, which, thus, leads to the higher total elongation than the Mg-2Gd alloy.

Keywords: Mg-Li-Gd dual-phase alloy, phase boundary, HDI stress, dislocation slip activity, mechanical properties

Procedia PDF Downloads 205
2381 Consumption of Animal and Vegetable Protein on Muscle Power in Road Cyclists from 18 to 20 Years in Bogota, Colombia

Authors: Oscar Rubiano, Oscar Ortiz, Natalia Morales, Lida Alfonso, Johana Alvarado, Adriana Gutierrez, Daniel Botero

Abstract:

Athletes who usually use protein supplements, are those who practice strength and power sports, whose goal is to achieve a large muscle mass. However, it has also been explored in sports or endurance activities such as cycling, and where despite requiring high power, prominent muscle development can impede good competitive performance due to the determinant of body mass for good performance of the athlete body. This research shows, the effect with protein supplements establishes a protein - muscle mass ratio, although in a lesser proportion the relationship between protein types and muscle power. Thus, we intend to explore as a first approximation, the behavior of muscle power in lower limbs after the intake of two protein supplements from different sources. The aim of the study was to describe the behavior of muscle power in lower limbs after the consumption of animal protein (AP) and vegetable protein (VP) in four route cyclists from 18 to 20 years of the Bogota cycling league. The methodological design of this study is quantitative, with a non-probabilistic sampling, based on a pre-experimental model. The jumping power was evaluated before and after the intervention by means of the squat jump test (SJ), Counter movement jump (CMJ) and Abalacov (AB). Cyclists consumed a drink with whey protein and a soy isolate after training four times a week for three months. The amount of protein in each cyclist, was calculated according to body weight (0.5 g / kg of muscle mass). The results show that subjects who consumed PV improved muscle strength and landing strength. In contrast, the power and landing force decreased for subjects who consumed PA. For the group that consumed PV, the increase was positive at 164.26 watts, 135.70 watts and 33.96 watts for the AB, SJ and CMJ jumps respectively. While for PA, the differences of the medians were negative at -32.29 watts, -82.79 watts and -143.86 watts for the AB, SJ and CMJ jumps respectively. The differences of the medians in the AB jump were positive for both the PV (121.61 Newton) and PA (454.34 Newton) cases, however, the difference was greater for PA. For the SJ jump, the difference for the PA cases was 371.52 Newton, while for the PV cases the difference was negative -448.56 Newton, so the difference was greater in the SJ jump for PA. In jump CMJ, the differences of the medians were negative for the cases of PA and PV, being -7.05 for PA and - 958.2 for PV. So the difference was greater for PA. The conclusion of this study shows that serum protein supplementation showed no improvement in muscle power in the lower limbs of the cyclists studied, which could suggest that whey protein does not have a beneficial effect on performance in terms of power, either, showed an impact on body composition. In contrast, supplementation with soy isolate showed positive effects on muscle power, body.

Keywords: animal protein (AP), muscle power, supplements, vegetable protein (VP)

Procedia PDF Downloads 178