Search results for: rock joints

Authors: Upamanyu Majumder, Angshuman Das

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Friction Stir Welding (FSW) is a Solid-State joining process. Unlike fusion welding techniques it does not involve operation above the melting point temperature of metals, but above the re-crystallization temperature. FSW also does not involve fusion of other material. FSW of ALUMINIUM has been commercialized and recent studies on joining dissimilar metals have been studied. Friction stir welding was introduced and patented in 1991 by The Welding Institute. For this paper, a total of nine samples each of copper and ALUMINIUM(Dissimilar metals) were welded using FSW process and Vickers Hardness were conducted on each of the samples.

Keywords: friction stir welding (FSW), recrystallization temperature, dissimilar metals, aluminium-copper, Vickers hardness test

Procedia PDF Downloads 335

Authors: A. Saghatelyan, Sh. Asmaryan, G. Tepanosyan, V. Muradyan

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One of major concern to Armenia has been soil degradation emerged as a result of unsustainable management and use of grasslands, this in turn largely impacting environment, agriculture and finally human health. Hence, assessment of soil degradation is an essential and urgent objective set out to measure its possible consequences and develop a potential management strategy. Since recently, an essential tool for assessing pasture degradation has been remote sensing (RS) technologies. This research was done with an intention to measure preciseness of Linear spectral unmixing (LSU) and NDVI-SMA methods to estimate soil surface components related to degradation (fractional vegetation cover-FVC, bare soils fractions, surface rock cover) and determine appropriateness of these methods for mapping man-induced soil degradation in high mountain pastures. Taking into consideration a spatially complex and heterogeneous biogeophysical structure of the studied site, we used high resolution multispectral QuickBird imagery of a pasture site in one of Armenia’s rural communities - Nerkin Sasoonashen. The accuracy assessment was done by comparing between the land cover abundance data derived through RS methods and the ground truth land cover abundance data. A significant regression was established between ground truth FVC estimate and both NDVI-LSU and LSU - produced vegetation abundance data (R2=0.636, R2=0.625, respectively). For bare soil fractions linear regression produced a general coefficient of determination R2=0.708. Because of poor spectral resolution of the QuickBird imagery LSU failed with assessment of surface rock abundance (R2=0.015). It has been well documented by this particular research, that reduction in vegetation cover runs in parallel with increase in man-induced soil degradation, whereas in the absence of man-induced soil degradation a bare soil fraction does not exceed a certain level. The outcomes show that the proposed method of man-induced soil degradation assessment through FVC, bare soil fractions and field data adequately reflects the current status of soil degradation throughout the studied pasture site and may be employed as an alternate of more complicated models for soil degradation assessment.

Keywords: Armenia, linear spectral unmixing, remote sensing, soil degradation

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Authors: Christian Ogubuchi Ede, Moses Oghenenyoreme Eyankware

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This study assessed the concentration of heavy metals (HMs) in soil, rock, mine dump pile, and water from Oshiri and Ishiagu areas of Ebonyi State. Investigations on mobile fraction equally evaluated the geochemical condition of different HM using UV spectrophotometer for Mineralized and unmineralized rocks, dumps, and soil, while AAS was used in determining the geochemical nature of the water system. Analysis revealed very high pollution of Cd mostly in Ishiagu (Ihetutu and Amaonye) active mine zones and with subordinates enrichments of Pb, Cu, As, and Zn in Amagu and Umungbala. Oshiri recorded sparingly moderate to high contamination of Cd and Mn but out rightly high anthropogenic input. Observation showed that most of the contamination conditions were unbearable while at the control but decrease with increasing distance from the mine vicinity. The potential heavy metal risk of the environments was evaluated using the risk factors such as enrichment factor, index of Geoacumulation, Contamination Factor, and Effect Range Median. Cadmium and Zn showed moderate to extreme contamination using Geoaccumulation Index (Igeo) while Pb, Cd, and As indicated moderate to strong pollution using the Effect Range Median. Results, when compared with the allowable limits and standards, showed the concentration of the metals in the following order Cd>Zn>Pb>As>Cu>Ni (rocks), Cd>As>Pb>Zn>Cu>Ni (soil) while Cd>Zn>As>Pb> Cu (for mine dump pile. High concentrations of Zn and As were recorded more in mine pond and salt line/drain channels along active mine zones, it heightened its threat during the rainy period as it settles into river course, living behind full-scale contaminations to inhabitants depending on it for domestic uses. Pb and Cu with moderate pollution were recorded in surface/stream water source as its mobility were relatively low. Results from Ishiagu Crush rock sites and Fedeco metallurgical and auto workshop where groundwater contamination was seen infiltrating some of the wells points gave rise to values that were 4 times high than the allowable limits. Some of these metal concentrations according to WHO (2015) if left unmitigated pose adverse effects to the soil and human community.

Keywords: water, geo-accumulation, heavy metals, mine and Nigeria.

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Authors: Meysam Lak, Mohammad Fatehi Marji, Alireza Yarahamdi Bafghi, Abolfazl Abdollahipour

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A wellbore is a hole that is drilled to aid in the exploration and recovery of natural resources including oil and gas. Occasionally, in order to increase productivity index and porosity of the wellbore and reservoir, the well stimulation methods have been used. Hydraulic fracturing is one of these methods. Moreover, several explosions at the end of the well can stimulate the reservoir and create fractures around it. In this study, crack initiation in rock around the wellbore has been numerically modeled due to explosion. One, two, three, and four pairs of explosion have been set at the end of the wellbore on its wall. After each stage of the explosion, results have been presented and discussed. Results show that this method can initiate and probably propagate several fractures around the wellbore.

Keywords: crack initiation, explosion, finite difference modelling, well productivity

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Authors: Aboozar Aghaei

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In the present work, the dissimilar Monel400 and SS316 were joined by friction stir welding (FSW). The applied rotating speed was 400 rpm, whereas the traverse speed varied between 50 and 150 mm/min. At a constant rotating speed, the sound welds were obtained at the welding speeds of 50 and 100 mm/min. However, a groove-like defect was formed when the welding speed exceeded 100 mm/min. The mechanical properties of the joints were evaluated using tensile and fatigue tests. The fatigue strength of dissimilar FSWed specimen was higher than that of both Monel400 and SS316. To study the failure behavior of FSWed specimens, the fracture surfaces were analyzed using scanning electron microscope (SEM). The failure analysis indicates that different mechanisms may contribute to the fracture of welds. This was attributed to the dissimilar characteristics of dissimilar materials exhibiting different failure behaviors.

Keywords: mechanical properties, stainless steel, frictions, monel

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Authors: Christopher Spiewak, M. R. Islam, Mohammad Arifur Rahaman, Mohammad H. Rahman, Roger Smith, Maarouf Saad

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For those who have lost the ability to move their hand, going through repetitious motions with the assistance of a therapist is the main method of recovery. We have been developed a robotic assistive device to rehabilitate the hand motions in place of the traditional therapy. The developed assistive device (RAD-HR) is comprised of four degrees of freedom enabling basic movements, hand function, and assists in supporting the hand during rehabilitation. We used a nonlinear computed torque control technique to control the RAD-HR. The accuracy of the controller was evaluated in simulations (MATLAB/Simulink environment). To see the robustness of the controller external disturbance as modelling uncertainty (±10% of joint torques) were added in each joints.

Keywords: biorobotics, rehabilitation, robotic assistive device, exoskeleton, nonlinear control

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Authors: Elad Harison

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The paper identifies the complex links between post-COVID-19 inflationary pressures and global supply chains. Throughout the COVID-19 lockdowns and long periods after the termination of social distancing policies, consumers, notably in the U.S., have confronted and still face disruptions in the supply of goods. The study analyzes the monetary policy in the U.S. that led to the significant shift in consumer demand during a limited supply period, hence resulting in shortages and emphasizing inflationary dynamics. We argue that the monetary guidelines applied by the U.S. government further elevated the scope of supply chain disruptions.

Keywords: consumer demand, COVID-19, inflation, monetary policy, supply chain

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Authors: Vijayakameswara Rao Neralla, Jueun Jeon, Jae Hyung Park

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To develop a potential nanocarrier for diagnosis and treatment of rheumatoid arthritis (RA), we prepared a hyaluronic acid (HA)-5β-cholanic acid (CA) conjugate with an acid-labile ketal linker. This conjugate could self-assemble in aqueous conditions to produce pH-responsive HA-CA nanoparticles as potential carriers of the anti-inflammatory drug methotrexate (MTX). MTX was rapidly released from nanoparticles under inflamed synovial tissue in RA. In vitro cytotoxicity data showed that pH-responsive HA-CA nanoparticles were non-toxic to RAW 264.7 cells. In vivo biodistribution results confirmed that, after their systemic administration, pH-responsive HA-CA nanoparticles selectively accumulated in the inflamed joints of collagen-induced arthritis mice. These results indicate that pH-responsive HA-CA nanoparticles represent a promising candidate as a drug carrier for RA therapy.

Keywords: rheumatoid arthritis, hyaluronic acid, nanocarrier, self-assembly, MTX

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Authors: D. Maneetham

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The developed exoskeleton device has to control joints between shoulder and arm. Exoskeleton device can help patients with hemiplegia upper so that the patient can help themselves in their daily life. Exoskeleton device includes a robot arm wear that looks like the movement is similar to the normal arm. Exoskeleton arm is powered by the motor through the cable with a control system that developed to control the movement of the joint of a robot arm. The arm will include the shoulder, the elbow, and the wrist. The control system is used Arduino Mega 2560 controller and the operation of the DC motor through the relay module. The control system can be divided into two modes such as the manual control with the joystick mode and automatically control with the movement of the head by Gyro sensor. The controller is also designed to move between the shoulder and the arm movement from their original location. Results have shown that the controller gave the best performance and all movements can be controlled.

Keywords: exoskeleton arm, hemiplegia upper, shoulder and arm, stroke

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Authors: Rusudan Chagelishvili, Nino Sulava, Tamar Beridze, Nana Rezesidze, Nikoloz Tatuashvili

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The South Caucasus is one of the most important centers of prehistoric metallurgy, known for its Colchian bronze culture. Modern Lechkhumi – historical Mountainous Colchis where the existence of prehistoric metallurgy is confirmed by the discovery of many artifacts is a part of this area. Studies focused on prehistoric smelting sites, related artefacts, and ore deposits have been conducted during last ten years in Lechkhumi. More than 20 prehistoric smelting sites and artefacts associated with metallurgical activities (ore roasting furnaces, slags, crucible, and tuyères fragments) have been identified so far. Within the framework of integrated studies was established that these sites were operating in 13-9 centuries B.C. and used for copper smelting. Palynological studies of slags revealed that chestnut (Castanea sativa) and hornbeam (Carpinus sp.) wood were used as smelting fuel. Geological exploration-analytical studies revealed that copper ore mining, processing, and smelting sites were distributed close to each other. Despite recent complex data, the signs of prehistoric mines (trenches) haven’t been found in this part of the study area so far. Since 2018 the archaeological-geological exploration has been focused on the southern part of Lechkhumi and covered the areas of villages Okureshi and Opitara. Several copper smelting sites (Okureshi 1 and 2, Opitara 1), as well as a Colchian Bronze culture settlement, have been identified here. Three mine workings have been found in the narrow gorge of the river Rtkhmelebisgele in the vicinities of the village Opitara. In order to establish a link between the Opitara-Okureshi archaeometallurgical sites, Late Bronze Age settlements, and mines, various scientific analytical methods -mineralized rock and slags petrography and atomic absorption spectrophotometry (AAS) analysis have been applied. The careful examination of Opitara mine workings revealed that there is a striking difference between the mine #1 on the right bank of the river and mines #2 and #3 on the left bank. The first one has all characteristic features of the Soviet period mine working (e. g. high portal with angular ribs and roof showing signs of blasting). In contrast, mines #2 and #3, which are located very close to each other, have round-shaped portals/entrances, low roofs, and fairly smooth ribs and are filled with thick layers of river sediments and collapsed weathered rock mass. A thorough review of the publications related to prehistoric mine workings revealed some striking similarities between mines #2 and #3 with their worldwide analogues. Apparently, the ore extraction from these mines was conducted by fire-setting applying primitive tools. It was also established that mines are cut in Jurassic mineralized volcanic rocks. Ore minerals (chalcopyrite, pyrite, galena) are related to calcite and quartz veins. The results obtained through the petrochemical and petrography studies of mineralized rock samples from Opitara mines and prehistoric slags are in complete correlation with each other, establishing the direct link between copper mining and smelting within the study area. Acknowledgment: This work was supported by the Shota Rustaveli National Science Foundation of Georgia (grant # FR-19-13022).

Keywords: archaeometallurgy, Mountainous Colchis, mining, ore minerals

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Authors: Mohsen Hababalahi, Morteza Bastami

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Buried pipeline damage correlations are critical part of loss estimation procedures applied to lifelines for future earthquakes. The vulnerability of buried pipelines against earthquake and liquefaction has been observed during some of previous earthquakes and there are a lot of comprehensive reports about this event. One of the main reasons for impairment of buried pipelines during earthquake is liquefaction. Necessary conditions for this phenomenon are loose sandy soil, saturation of soil layer and earthquake intensity. Because of this fact that pipelines structure are very different from other structures (being long and having light mass) by paying attention to the results of previous earthquakes and compare them with other structures, it is obvious that the danger of liquefaction for buried pipelines is not high risked, unless effective parameters like earthquake intensity and non-dense soil and other factors be high. Recent liquefaction researches for buried pipeline include experimental and theoretical ones as well as damage investigations during actual earthquakes. The damage investigations have revealed that a damage ratio of pipelines (Number/km ) has much larger values in liquefied grounds compared with one in shaking grounds without liquefaction according to damage statistics during past severe earthquakes, and that damages of joints and pipelines connected with manholes were remarkable. The purpose of this research is numerical study of buried pipelines under the effect of liquefaction by case study of the 2013 Dashti (Iran) earthquake. Water supply and electrical distribution systems of this township interrupted during earthquake and water transmission pipelines were damaged severely due to occurrence of liquefaction. The model consists of a polyethylene pipeline with 100 meters length and 0.8 meter diameter which is covered by light sandy soil and the depth of burial is 2.5 meters from surface. Since finite element method is used relatively successfully in order to solve geotechnical problems, we used this method for numerical analysis. For evaluating this case, some information like geotechnical information, classification of earthquakes levels, determining the effective parameters in probability of liquefaction, three dimensional numerical finite element modeling of interaction between soil and pipelines are necessary. The results of this study on buried pipelines indicate that the effect of liquefaction is function of pipe diameter, type of soil, and peak ground acceleration. There is a clear increase in percentage of damage with increasing the liquefaction severity. The results indicate that although in this form of the analysis, the damage is always associated to a certain pipe material, but the nominally defined “failures” include by failures of particular components (joints, connections, fire hydrant details, crossovers, laterals) rather than material failures. At the end, there are some retrofit suggestions in order to decrease the risk of liquefaction on buried pipelines.

Keywords: liquefaction, buried pipelines, lifelines, earthquake, finite element method

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Authors: M. Karzhauov, А. Mukhambetova, M. Sarsenova, E. Raimagambetov, V. Ogay

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Regeneration of injured articular cartilage remains one of the most difficult and unsolved problems in traumatology and orthopedics. Currently, for the treatment of cartilage defects surgical techniques for stimulation of the regeneration of cartilage in damaged joints such as multiple microperforation, mosaic chondroplasty, abrasion and microfractures is used. However, as shown by clinical practice, they can not provide a full and sustainable recovery of articular hyaline cartilage. In this regard, the current high hopes in the regeneration of cartilage defects reasonably are associated with the use of tissue engineering approaches to restore the structural and functional characteristics of damaged joints using stem cells, growth factors and biopolymers or scaffolds. The purpose of the present study was to investigate the effects of chondroinductive growth factors and synovium-derived mesenchymal stem cells (SD-MSCs) on the regeneration of cartilage defects in rabbits. SD-MSCs were isolated from the synovium membrane of Flemish giant rabbits, and expanded in complete culture medium α-MEM. Rabbit SD-MSCs were characterized by CFU-assay and by their ability to differentiate into osteoblasts, chondrocytes and adipocytes. The effects of growth factors (TGF-β1, BMP-2, BMP-4 and IGF-I) on MSC chondrogenesis were examined in micromass pellet cultures using histological and biochemical analysis. Articular cartilage defect (4mm in diameter) in the intercondylar groove of the patellofemoral joint was performed with a kit for the mosaic chondroplasty. The defect was made until subchondral bone plate. Delivery of SD-MSCs and growth factors was conducted in combination with hyaloronic acid (HA). SD-MSCs, growth factors and control groups were compared macroscopically and histologically at 10, 30, 60 and 90 days aftrer intra-articular injection. Our in vitro comparative study revealed that TGF-β1 and BMP-4 are key chondroinductive factors for both the growth and chondrogenesis of SD-MSCs. The highest effect on MSC chondrogenesis was observed with the synergistic interaction of TGF-β1 and BMP-4. In addition, biochemical analysis of the chondrogenic micromass pellets also revealed that the levels of glycosaminoglycans and DNA after combined treatment with TGF-β1 and BMP-4 was significantly higher in comparison to individual application of these factors. In vivo study showed that for complete regeneration of cartilage defects with intra-articular injection of SD-MSCs with HA takes time 90 days. However, single injection of SD-MSCs in combiantion with TGF-β1, BMP-4 and HA significantly promoted regeneration rate of the cartilage defects in rabbits. In this case, complete regeneration of cartilage defects was observed in 30 days after intra-articular injection. Thus, our in vitro and in vivo study demonstrated that combined application of rabbit SD-MSC with chondroinductive growth factors and HA results in strong synergistic effect on the chondrogenesis significantly enhancing regeneration of the damaged cartilage.

Keywords: Mesenchymal stem cells, synovium, chondroinductive factors, TGF-β1, BMP-2, BMP-4, IGF-I

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Authors: E. Lam, Z. D. Yang, B. Li, I. Ho, T. Wong, V. Wong

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This paper reports some of the recent studies on strengthening of reinforced concrete members by ferrocement. Using mortar in ferrocement with high tensile strength, tensile properties of (high performance) ferrocement can be enhanced. In the proposed strengthening strategy, defective concrete cover of structural members is replaced by ferrocement so as to increase the load carrying capacity. This has been successfully applied to strengthen columns and beam-column joints. To facilitate the ease of application of the proposed strengthening strategy, mortar in ferrocement is applied through dry spray shotcrete.

Keywords: ferrocement, high performance ferrocement, dry, spray shotcrete, column, beam-column joint, strengthening

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Authors: Gowthamraj Vungarala

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This paper presents the experimental investigation on the bond strength, waterproofing abilities and flexibility of tile joint when Ordinary Portland Cement (OPC) or White Portland Cement (WPC) CEM II A-LL 42.5N and porcelain powder graded between 200 microns and 75 microns is mixed with vinyl acetate monomer (VAM), hydroxypropyl methyl cellulose ether, ethylene co-polymer rubber powder and Styrene butyl rubber (SBR). Use of porcelain powder which is tough to decompose as a form of industrial refuse which helps environmental safety and waste usage.

Keywords: styrene butane rubber, hydroxypropyl methyl cellulose ether, vinyl acetate monomer, polymer modified cement, polyethylene, porcelain powder

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Authors: M. Jamuna Rani, K. Ramanathan

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A steam power plant is housed with various types of equipments like boiler, turbine, heat exchanger etc. These equipments are mainly connected with piping systems. Such a piping layout design depends mainly on stress analysis and flexibility. It will vary with respect to pipe geometrical properties, pressure, temperature, and supports. The present paper is to analyze the presence and effect of hangers and expansion joints in the piping layout/routing using CAESAR-II software. Main aim of piping stress analysis is to provide adequate flexibility for absorbing thermal expansion, code compliance for stresses and displacement incurred in piping system. The design is said to be safe if all these are in allowable range as per code. In this study, a sample problem is considered for analysis as per power piping ASME B31.1 code and the results thus obtained are compared.

Keywords: ASTM B31.1, hanger, expansion joint, CAESAR-II

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Authors: Cláudia Pereira, Lívia Boeschenstein

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This article aims to present an analysis of rock band t-shirts as an element that claims a certain identity in modern-contemporary culture. This work focuses on the study of t-shirts that display the name, related elements and the logo of punk band The Ramones, because of its strong presence in the collective mind along the last decades. As we shall see, it is possible to observe a phenomenon of symbolic transition from the original cultural place of that object. At first, it was a piece of cloth that had been part of a specific subculture and then it became just a generic item diluted by the mainstream. This symbolic transitional phenomenon is significant in many ways and will be discussed furthermore. For the analysis, we begin with a brief introduction to the history of the band, followed by the study about the vintage rock band T-shirts and their meanings. From there, we will turn to a historical contextualization of band T-shirts as a subcultural item and to its redefinition after the appropriation made by the mainstream. To guide this reasoning, it will be used theories about the styles, subcultures and youth culture and about material culture from an anthropological perspective. In addition, we shall see the theories and concepts of social representations in order to understand the ways of using the Ramones’s T-shirt as a representative element of a fashionable style. This T-shirt, after being resignified by the standardization and the massive consumption, no longer symbolizes the punk movement, its behavioral motivations and original policies. Also has little to do with the rage the working class suburbs of London or New York. It seems to be a mute and vague sign of a restricted rebellion, foreseen and framed establishing a stylistic contrast to the designer clothes and good behavior predicted by establishment. It's an item that composes a specific style available on the market, but at the same time is accepted by the mainstream and provides a subcultural association that has some prestige in society. Another perspective is that of resignification loop. As the same way that punk resignified the conventional goods for their own social standards, fashion resignifies what was said to be an object of a subculture and absorbs in their own mass culture standards. Therefore, outsiders to the punk phenomenon wearing Ramones’s T-shirts can be perceived negatively by subcultural members, but at the same time are well received by those who are partially unaware or completely out of subcultural context. For the general public, the stamp of the Ramones’s logo happens to be appreciated as a diffuse allusion to a punk style, since its original meaning has being entirely neutralized.

Keywords: social representations, subcultures, material culture, punk

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Authors: G. Patricia Abdel Rahim, Jairo Arbey Rodriguez M, María Guadalupe Moreno Armenta

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The present study shows the structural, electronic and magnetic properties of magnesium (Mg) and bismuth (Bi) in a supercell (1X1X5). For both materials were studied in five crystalline structures: rock salt (NaCl), cesium chloride (CsCl), zinc-blende (ZB), wurtzite (WZ), and nickel arsenide (NiAs), using the Density Functional Theory (DFT), the Generalized Gradient Approximation (GGA), and the Full Potential Linear Augmented Plane Wave (FP-LAPW) method. By means of fitting the Murnaghan's state equation we determine the lattice constant, the bulk modulus and it's derived with the pressure. Also we calculated the density of states (DOS) and the band structure.

Keywords: bismuth, magnesium, pseudo-potential, supercell

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Authors: Richard E. Miller

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12.7-mm thick plates of 6061-T6511 aluminum alloy and high hardness steel (528 HV) were successfully joined by a friction stir bonding process using a tungsten-rhenium stir tool. Process parameter variation experiments, which included tool design geometry, plunge and traverse rates, tool offset, spindle tilt, and rotation speed, were conducted to develop a parameter set which yielded a defect free joint. Laboratory tensile tests exhibited yield stresses which exceed the strengths of comparable AA6061-to-AA6061 fusion and friction stir weld joints. Scanning electron microscopy and energy dispersive X-ray spectroscopy analysis also show atomic diffusion at the material interface region.

Keywords: dissimilar materials, friction stir, welding, materials science

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Authors: Thayalan Nall, Andreas Putra

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A major offshore reclamation work is currently underway in Southeast Asia for a container terminal. The total extent of the reclamation extent is 2600m x 800m and the seabed level is around -5mRL below mean sea level. Subsoil profile below seabed comprises soft marine clays of thickness varying from 8m to 15m. To contain the dredging spoil within the reclamation area, perimeter bunds have been constructed to +2.5mRL. They include breakwaters of trapezoidal geometry, made of boulder size rock along the northern, eastern and western perimeters, with a sand bund along the southern perimeter. Breakwaters were constructed on a composite bamboo pile and raft foundation system. Bamboo clusters 8m long, with 7 individual Bamboos bundled together as one, have been installed within the footprint of the breakwater below seabed in soft marine clay. To facilitate drainage two prefabricated vertical drains (PVD) have been attached to each cluster. Once the cluster piles were installed, a bamboo raft was placed as a load transfer platform. Rafts were made up of 5 layers of bamboo mattress, and in each layer bamboos were spaced at 200mm centres. The rafts wouldn’t sink under their own weight, and hence, they were sunk by loading quarry run rock onto them. Bamboo is a building material available in abundance in Indonesia and obtained at a relatively low cost. They are commonly used as semi-rigid inclusions to improve compressibility and stability of soft soils. Although bamboo is widely used in soft soil engineering design, no local design guides are available and the designs are carried out based on local experience. In June 2015, when the 1st load of sand was pumped by a dredging vessel next to the breakwater, a 150m long section of the breakwater underwent failure and displaced the breakwater between 1.2m to 4.0m. The cause of the failure was investigated to implement remedial measures to reduce the risk of further failures. Analyses using both limit equilibrium approach and finite element modelling revealed two plausible modes of breakwater failure. This paper outlines: 1) Developed Geology and the ground model, 2) The techniques used for the installation of bamboo piles, 3) Details of the analyses including modes and mechanism of failure and 4) Design changes incorporated to reduce the risk of failure.

Keywords: bamboo piles, ground improvement, reclamation, breakwater failure

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Authors: Prakher Mishra, Dikshant Bodana, Saloni Desai, Sudhanshu Dixit, Sopan Agarwal, Shriraj Patel

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Railways are sometimes lifeline of nations as they consist of huge network of rail lines and bridges. Reportedly many of the bridges are aging, weak, distressed and accident prone. It becomes a really challenging task for Engineers and workers to keep up a regular maintenance schedule for proper functioning which itself is quite a hard hitting job. In this paper we have come up with an innvovative wireless system of maintenance called BriMAIN. In this system we have installed two types of sensors, first one is called a force sensor which will continously analyse the readings of pressure at joints of the bridges and secondly an MPU-6050 triaxial gyroscope+accelerometer which will analyse the deflection of the deck of the bridge. Apart from this a separate database is also being made at the server room so that the data can be visualized by the engineers and a warning can be issued in case reading of the sensors goes above threshold.

Keywords: Accelerometer, B-MAIN, Gyroscope, MPU-6050

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Authors: Reut Lanyado, David Mendlovic

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Most biological methods for authentication require special equipment and, some of them are easy to fake. We proposed a method for authentication based on hand movement while typing a sentence with a regular camera. This technique uses the full video of the hand, which is harder to fake. In the first phase, we tracked the hand joints in each frame. Next, we represented a single frame for each individual using our Pose Agnostic Rotation and Movement (PARM) dimensional space. Then, we indicated a full video of hand movement in a fixed low dimensional space using this method: Fixed Dimension Video by Interpolation Statistics (FDVIS). Finally, we identified each individual in the FDVIS representation using unsupervised clustering and supervised methods. Accuracy exceeds 96% for 80 individuals by using supervised KNN.

Keywords: authentication, feature extraction, hand recognition, security, signal processing

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Authors: Richard Colwell, Thomas Englert

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In cryogenic liquefaction processes, brazed aluminum core heat exchangers are used to minimize surface area/volume of the exchanger. Aluminum alloy (5083-H321; UNS A95083) piping must transition to higher melting point 304L stainless steel piping outside of the heat exchanger kettle or cold box for safety reasons. Since aluminum alloys and austenitic stainless steel cannot be directly welded to together, a transition joint consisting of 5 layers of different metals explosively bonded are used. Failures of two of these joints resulted in process shut-down and loss of revenue. Failure analyses, FEA analysis, and mock-up testing were performed by multiple teams to gain a further understanding into the failure mechanisms involved.

Keywords: explosion bonding, intermetallic compound, thermal strain, titanium-nickel Interface

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Authors: Babak H. Mamaqani, Alimohammad Entezarmahdi

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There are many researches on parameters affecting seismic behavior of steel moment frames. Great deal of these researches considers cover plate connections with or without haunch and direct beam to column connection for exterior columns. Also there are experimental results for interior connections with equal beam depth on both sides but not much research has been performed on the seismic behavior of joints with unequal beam depth. Based on previous experimental results, a series of companion analyses have been set up considering different beam height and connection detailing configuration to investigate the seismic behavior of the connections. Results of this study indicate that when the differences between beams height on both side increases, use of haunch connection system leads to significant improvement in the seismic response whereas other configurations did not provide satisfying results.

Keywords: analytical modeling, Haunch connection, seismic design, unequal beam depth

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Authors: Gurjinder Singh, Ankur Gill, Amardeep Singh Kang

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In the present work an effort has been made to study the influence of the welding parameters on tensile strength of friction stir welding of aluminum. Three process parameters tool rotation speed, welding speed, and shoulder diameter were selected for the study. Two level factorial design of eight runs was selected for conducting the experiments. The mathematical model was developed from the data obtained. The significance of coefficients and adequacy of developed models were tested by ‘t’ test and ‘F’ test respectively. The effects of process parameters on mechanical properties have been represented in the form of graphs for better understanding.

Keywords: friction stir welding, aluminium alloy, mathematical model, welding speed

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Authors: S. Ali, R. Yunus, A. Arif, Y. Ayaz, M. Baber Sial, R. Asif, N. Naseer, M. Jawad Khan

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In this study, we have proposed a gesture to emotion recognition method using flex sensors mounted on metacarpophalangeal joints. The flex sensors are fixed in a wearable glove. The data from the glove are sent to PC using Wi-Fi. Four gestures: finger pointing, thumbs up, fist open and fist close are performed by five subjects. Each gesture is categorized into sad, happy, and excited class based on the velocity and acceleration of the hand gesture. Seventeen inspectors observed the emotions and hand gestures of the five subjects. The emotional state based on the investigators assessment and acquired movement speed data is compared. Overall, we achieved 77% accurate results. Therefore, the proposed design can be used for emotional state detection applications.

Keywords: emotion identification, emotion models, gesture recognition, user perception

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Authors: Grmay Kassa Brhane, Hailemariam Siyum Mekonen

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This study was designed to identify the hydrogeochemical and anthropogenic processes controlling the evaluation of groundwater chemistry in the Ellala catchment which covers about 296.5 km2 areal extent. The chemical analysis revealed that the major ions in the groundwater are Ca2+, Mg2+, Na+, and K+ (cations) and HCO3-, PO43-, Cl-, NO3-, and SO42-(anions). Most of the groundwater samples (68.42%) revealed that the groundwater in the catchment is non-alkaline. In addition to the contribution of aquifer material, the solid materials and liquid wastes discharged from different sources can be the main sources of pH and EC in the groundwater. It is observed that the EC of the groundwater is fairly correlated with the DTS. This indicates that high mineralized water is more conductor than water with low concentration. The degree of salinity of the groundwater increases along the groundwater flow path from East to West; then, areas surrounding Mekelle City are highly saline due to the liquid and solid wastes discharged from the city and the industries. The groundwater facies in the catchment are predominated with calcium, magnesium, and bicarbonate which are labeled as Ca-Mg-HCO3 and Mg-Ca-HCO3. The main geochemical process controlling the evolution of the groundwater chemistry in the catchment is rock-water interaction, particularly carbonate dissolution. Due to the clay layer in the aquifer, the reverse is ion exchange. Non-significant silicate weathering and halite dissolution also contribute to the evolution of groundwater chemistry in the catchment. The groundwater in the catchment is dominated by the meteoritic origin although it needs further groundwater chemistry study with isotope dating analysis. The groundwater is under-saturated with calcite, dolomite, and aragonite minerals; hence, the more these minerals encounter the groundwater, the more the minerals dissolve. The main source of calcium and magnesium in groundwater is the dissolution of carbonate minerals (calcite and dolomite) since carbonate rocks are the dominant aquifer materials in the catchment. In addition to this, the weathering of dolerite rock is a possible source of magnesium ions. The relatively higher concentration of sodium over chloride indicates that the source of sodium-ion is reverse ion exchange and/or weathering of sodium-bearing materials, such as shale and dolerite rather than halite dissolution. High concentration of phosphate, nitrate, and chloride in the groundwater is the main anthropogenic source that needs treatment, quality control, and management in the catchment. From the Base Exchange Index Analysis, it is possible to understand that, in the catchment, the groundwater is dominated by the meteoritic origin, although it needs further groundwater chemistry study with isotope dating analysis.

Keywords: Ellala catchment, factor, chemistry, geochemical, groundwater

Procedia PDF Downloads 49

Authors: Babitha Elizabeth Philip

Abstract:

This paper aims to study in general about bridges without expansion joints. Integral Abutment Bridges (IAB) fall into this category of bridges. They are having a continuous deck and also the girders are integrated into the abutments. They are most cost effective system in terms of construction, maintenance, and longevity. The main advantage of IAB is that it is corrosion resistant since water is not allowed to pass through the structure. The other attractions of integral bridges are its simple and rapid construction, smooth and uninterrupted deck which provides a safe ride. Also damages to the abutments can be avoided to a great extent due to better load distribution at the bridge ends. Damages due to improper drainage are not seen in IAB because of its properly drained approach slabs thus eliminating the possibility of erosion of the abutment backfill and freeze and thaw damage resulting from saturated backfill.

Keywords: continuous bridge, integral abutment bridge, joint bridge, life cycle cost, soil interaction

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Authors: Geum Yeon Sim, Jasal Patel, Anand Kumthekar, Stanley Wainapel

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A 65-year-old right-hand dominant African-American man, formerly employed as a security guard, was referred to Rehabilitation Medicine with bilateral hand stiffness and weakness. His past medical history was only significant for myelofibrosis, diagnosed 4 years earlier, for which he was receiving scheduled blood transfusions. Approximately 2 years ago, he began to notice stiffness and swelling in his non-dominant hand that progressed to pain and decreased strength, limiting his hand function. Similar but milder symptoms developed in his right hand several months later. There was no history of prior injury or exposure to cold. Physical examination showed enlargement of metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joints with finger flexion contractures, Swan-neck and Boutonniere deformities, and associated joint tenderness. Changes were more prominent in the left hand. X-rays showed mild osteoarthritis of several bilateral PIP joints. Anti-nuclear antibodies, rheumatoid factor, and cyclic citrullinated peptide antibodies were negative. MRI of the hand showed no erosions or synovitis. A rheumatology consultation was obtained, and the cause of his symptoms was attributed to myelofibrosis-related arthropathy with secondary osteoarthritis. The patient was tried on diclofenac cream and received a few courses of Occupational Therapy with limited functional improvement. Primary myelofibrosis (PMF) is a rare myeloproliferative neoplasm characterized by clonal proliferation of myeloid cells with variable morphologic maturity and hematopoietic efficiency. Rheumatic manifestations of malignancies include direct invasion, paraneoplastic presentations, secondary gout, or hypertrophic osteoarthropathy. PMF causes gradual bone marrow fibrosis with extramedullary metaplastic hematopoiesis in the liver, spleen, or lymph nodes. Musculoskeletal symptoms are not common and are not well described in the literature. The first reported case of myelofibrosis related arthritis was seronegative arthritis due to synovial invasion of myeloproliferative elements. Myelofibrosis has been associated with autoimmune diseases such as systemic lupus erythematosus, progressive systemic sclerosis, and rheumatoid arthritis. Gout has been reported in patients with myelofibrosis, and the underlying mechanism is thought to be related to the high turnover of nucleic acids that is greatly augmented in this disease. X-ray findings in these patients usually include erosive arthritis with synovitis. Treatment of underlying PMF is the treatment of choice, along with anti-inflammatory medications. Physicians should be cognizant of recognizing this rare entity in patients with PMF while maintaining clinical suspicion for more common causes of joint deformities, such as rheumatic diseases.

Keywords: myelofibrosis, arthritis, arthralgia, malignancy

Procedia PDF Downloads 77

Authors: Tshipeng Mwenze, Charles Okujeni, Abdi Siad, Russel Bailie, Dirk Frei, Marcelene Voigt, Petrus Le Roux

Abstract:

The Platreef is a platinum group element (PGE) deposit in the northern limb of the Bushveld Igneous Complex (BIC) which was emplaced as a series of mafic and ultramafic sills between the Main Zone (MZ) and the country rocks. The PGE mineralisation in the Platreef is hosted in different rock types, and its distribution and style vary with depth and along strike. This study contributes towards understanding the processes involved in the genesis of the Platreef. Twenty-four Platreef (2 harzburgites, 4 olivine pyroxenites, 17 feldspathic pyroxenites and 1 gabbronorite) and few MZ (1 gabbronorite and 1 leucogabbronorite) quarter core samples were collected from four drill cores (e.g., TN754, TN200, SS339, and OY482) and analysed for whole-rock Sr-Nd isotope data. The results show positive ɛNd values (+3.53 to +7.51) for harzburgites suggesting their parental magmas derived from the depleted Mantle. The remaining Platreef rocks have negative ɛNd values (-2.91 to -22.88) and show significant variations in Sr-Nd isotopic compositions. The first group of Platreef samples has relatively high isotopic compositions (ɛNd= -2.91 to -5.68; ⁸⁷Sr/⁸⁶Sri= 0.709177 - 0.711998). The second group of Platreef samples has Sr ratios (⁸⁷Sr/⁸⁶Sri= 0.709816-0.712106) overlapping with samples of the first group but slightly lower ɛNd values (-7.44 to -8.39). Lastly, the third group of Platreef samples has low ɛNd values (-10.82 to -14.32) and low Sr ratios (⁸⁷Sr/⁸⁶Sri= 0.707545-0.710042) than those from samples of the two Platreef groups mentioned above. There is, however, a Platreef sample with ɛNd value (-5.26) in range with the Platreef samples of the first group, but its Sr ratio (0.707281) is the lowest even when compared to samples of the third Platreef group. There are also five other Platreef samples which have either anomalous ɛNd or Sr ratios which make it difficult to assess their isotopic compositions relative to other samples. These isotopic variations for the Platreef samples indicate both multiple sources and multiple magma chambers where varying crustal contamination styles have operated during the evolution of these magmas prior their emplacements into the Platreef setting as sills. Furthermore, the MZ rocks have different Sr-Nd isotopic compositions (For OY482 gabbronorite [ɛNd= +0.65; ⁸⁷Sr/⁸⁶Sri= 0.711746]; for TN754 leucogabbronorite [ɛNd= -7.44; ⁸⁷Sr/⁸⁶Sri= 0.709322]) which do not only indicate different MZ magma chambers, but also different magmas from those of the Platreef. Although the Platreef is still considered a single stratigraphic unit in the northern limb of the BIC, its genesis involved multiple magmatic processes which evolved independently from each other.

Keywords: crustal contamination styles, magma chambers, magma sources, multiple sills emplacement

Procedia PDF Downloads 146

Authors: Aboozar Aghaei

Abstract:

In the present work, the dissimilar Monel400 and SS316 were joined by friction stir welding (FSW). The applied rotating speed was 400 rpm, whereas the traverse speed varied between 50 and 150 mm/min. At a constant rotating speed, the sound welds were obtained at the welding speeds of 50 and 100 mm/min. However, a groove-like defect was formed when the welding speed exceeded 100 mm/min. The mechanical properties of the joints were evaluated using tensile and fatigue tests. The fatigue strength of dissimilar FSWed specimens was higher than that of both Monel400 and SS316. To study the failure behavior of FSWed specimens, the fracture surfaces were analyzed using a scanning electron microscope (SEM). The failure analysis indicates that different mechanisms may contribute to the fracture of welds. This was attributed to the dissimilar characteristics of dissimilar materials exhibiting different failure behaviors.

Keywords: frictions stir welding (FSW), stainless steel, mechanical properties, Monel400

Procedia PDF Downloads 63