Search results for: damaged joint
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 1458

Search results for: damaged joint

1218 Effectiveness of Exercise and TENS in the Treatment of Temporomandibular Joint Disorders

Authors: Arben Murtezani, Shefqet Mrasori, Vančo Spirov, Bukurije Rama, Oliver Dimitrovski, Visar Bunjaku

Abstract:

Overview: Temporomandibular disorders (TMDs) are chronic musculoskeletal pain conditions. Clinical indicators of discomfort are related to the use of the joint stiffness during first motions after extended rest and restricted joint range of motion can cause substantial pain and disability. There is little evidence that physical therapy methods of management cause long-lasting reduction in signs and symptoms. Exercise programs premeditated to improve physical fitness have beneficial effects on chronic pain and disability of the musculoskeletal system. Objective: The aim of this study was to assess the effectiveness of physical therapy interventions in the management of temporomandibular disorders. Materials and Methods: A prospective comparative study with a 2-month follow-up period was conducted between April 2016 and June 2016 at the Physical Medicine and Rehabilitation Clinic in Prishtina. Forty six patients with TMDs, (more than three months duration of symptoms) were randomized into two groups: the TENS therapy group (n=24) and combination of active exercise and manual therapy group (n=22). The TENS therapy group patients were treated with twelve sessions of TENS. The treatment period of both groups was 3 weeks at an outpatient clinic. Following main outcome measures were evaluated: (1) pain at rest (2) pain at stress (3) impairment (4) mouth opening at base-line, before and after treatment and at 3 month follow-up. Results: Significant reduction in pain was observed in both treatment groups. In the TENS group 73% (16/22) achieved at least 80% improvement from baseline in TMJ pain at 2 months compared with 54% (13/24) in the exercise group (difference of 19%; 95% confidence interval 220 to 30%). Active and passive maximum mouth opening has been greater in the TENS group (p < 0.05). Conclusion: Exercise therapy in combination with TENS seems to be useful in the treatment of temporomandibular disorders.

Keywords: temporomandibular joint disorders, TENS, manual therapy, exercise

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1217 Temperature Evolution, Microstructure and Mechanical Properties of Heat-Treatable Aluminum Alloy Welded by Friction Stir Welding: Comparison with Tungsten Inert Gas

Authors: Saliha Gachi, Mouloud Aissani, Fouad Boubenider

Abstract:

Friction Stir Welding (FSW) is a solid-state welding technique that can join material without melting the plates to be welded. In this work, we are interested to demonstrate the potentiality of FSW for joining the heat-treatable aluminum alloy 2024-T3 which is reputed as difficult to be welded by fusion techniques. Thereafter, the FSW joint is compared with another one obtained from a conventional fusion process Tungsten Inert Gas (TIG). FSW welds are made up using an FSW tool mounted on a milling machine. Single pass welding was applied to fabricated TIG joint. The comparison between the two processes has been made on the temperature evolution, mechanical and microstructure behavior. The microstructural examination revealed that FSW weld is composed of four zones: Base metal (BM), Heat affected zone (HAZ), Thermo-mechanical affected zone (THAZ) and the nugget zone (NZ). The NZ exhibits a recrystallized equiaxed refined grains that induce better mechanical properties and good ductility compared to TIG joint where the grains have a larger size in the welded region compared with the BM due to the elevated heat input. The microhardness results show that, in FSW weld, the THAZ contains the lowest microhardness values and increase in the NZ; however, in TIG process, the lowest values are localized on the NZ.

Keywords: friction stir welding, tungsten inert gaz, aluminum, microstructure

Procedia PDF Downloads 245
1216 Operational Advantages of Tungsten Inert Gas over Metal Inert Gas Welding Process

Authors: Emmanuel Ogundimu, Esther Akinlabi, Mutiu Erinosho

Abstract:

In this research, studies were done on the material characterization of type 304 austenitic stainless steel weld produced by TIG (Tungsten Inert Gas) and MIG (Metal Inert Gas) welding processes. This research is aimed to establish optimized process parameters that will result in a defect-free weld joint, homogenous distribution of the iron (Fe), chromium (Cr) and nickel (Ni) was observed at the welded joint of all the six samples. The welded sample produced at the current of 170 A by TIG welding process had the highest ultimate tensile strength (UTS) value of 621 MPa at the welds zone, and the welded sample produced by MIG process at the welding current of 150 A had the lowest UTS value of 568 MPa. However, it was established that TIG welding process is more appropriate for the welding of type 304 austenitic stainless steel compared to the MIG welding process.

Keywords: microhardness, microstructure, tensile, MIG welding, process, tensile, shear stress TIG welding, TIG-MIG welding

Procedia PDF Downloads 153
1215 Improvement of the Q-System Using the Rock Engineering System: A Case Study of Water Conveyor Tunnel of Azad Dam

Authors: Sahand Golmohammadi, Sana Hosseini Shirazi

Abstract:

Because the status and mechanical parameters of discontinuities in the rock mass are included in the calculations, various methods of rock engineering classification are often used as a starting point for the design of different types of structures. The Q-system is one of the most frequently used methods for stability analysis and determination of support systems of underground structures in rock, including tunnel. In this method, six main parameters of the rock mass, namely, the rock quality designation (RQD), joint set number (Jn), joint roughness number (Jr), joint alteration number (Ja), joint water parameter (Jw) and stress reduction factor (SRF) are required. In this regard, in order to achieve a reasonable and optimal design, identifying the effective parameters for the stability of the mentioned structures is one of the most important goals and the most necessary actions in rock engineering. Therefore, it is necessary to study the relationships between the parameters of a system and how they interact with each other and, ultimately, the whole system. In this research, it has attempted to determine the most effective parameters (key parameters) from the six parameters of rock mass in the Q-system using the rock engineering system (RES) method to improve the relationships between the parameters in the calculation of the Q value. The RES system is, in fact, a method by which one can determine the degree of cause and effect of a system's parameters by making an interaction matrix. In this research, the geomechanical data collected from the water conveyor tunnel of Azad Dam were used to make the interaction matrix of the Q-system. For this purpose, instead of using the conventional methods that are always accompanied by defects such as uncertainty, the Q-system interaction matrix is coded using a technique that is actually a statistical analysis of the data and determining the correlation coefficient between them. So, the effect of each parameter on the system is evaluated with greater certainty. The results of this study show that the formed interaction matrix provides a reasonable estimate of the effective parameters in the Q-system. Among the six parameters of the Q-system, the SRF and Jr parameters have the maximum and minimum impact on the system, respectively, and also the RQD and Jw parameters have the maximum and minimum impact on the system, respectively. Therefore, by developing this method, we can obtain a more accurate relation to the rock mass classification by weighting the required parameters in the Q-system.

Keywords: Q-system, rock engineering system, statistical analysis, rock mass, tunnel

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1214 Numerical Modelling and Experiment of a Composite Single-Lap Joint Reinforced by Multifunctional Thermoplastic Composite Fastener

Authors: Wenhao Li, Shijun Guo

Abstract:

Carbon fibre reinforced composites are progressively replacing metal structures in modern civil aircraft. This is because composite materials have large potential of weight saving compared with metal. However, the achievement to date of weight saving in composite structure is far less than the theoretical potential due to many uncertainties in structural integrity and safety concern. Unlike the conventional metallic structure, composite components are bonded together along the joints where structural integrity is a major concern. To ensure the safety, metal fasteners are used to reinforce the composite bonded joints. One of the solutions for a significant weight saving of composite structure is to develop an effective technology of on-board Structural Health Monitoring (SHM) System. By monitoring the real-life stress status of composite structures during service, the safety margin set in the structure design can be reduced with confidence. It provides a means of safeguard to minimize the need for programmed inspections and allow for maintenance to be need-driven, rather than usage-driven. The aim of this paper is to develop smart composite joint. The key technology is a multifunctional thermoplastic composite fastener (MTCF). The MTCF will replace some of the existing metallic fasteners in the most concerned locations distributed over the aircraft composite structures to reinforce the joints and form an on-board SHM network system. Each of the MTCFs will work as a unit of the AU and AE technology. The proposed MTCF technology has been patented and developed by Prof. Guo in Cranfield University, UK in the past a few years. The manufactured MTCF has been successfully employed in the composite SLJ (Single-Lap Joint). In terms of the structure integrity, the hybrid SLJ reinforced by MTCF achieves 19.1% improvement in the ultimate failure strength in comparison to the bonded SLJ. By increasing the diameter or rearranging the lay-up sequence of MTCF, the hybrid SLJ reinforced by MTCF is able to achieve the equivalent ultimate strength as that reinforced by titanium fastener. The predicted ultimate strength in simulation is in good agreement with the test results. In terms of the structural health monitoring, a signal from the MTCF was measured well before the load of mechanical failure. This signal provides a warning of initial crack in the joint which could not be detected by the strain gauge until the final failure.

Keywords: composite single-lap joint, crack propagation, multifunctional composite fastener, structural health monitoring

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1213 Experimental Investigation of the Static and Dynamic Behaviour of Double Lap Joints

Authors: H. I. Beloufa, M. Tarfaoui

Abstract:

For many applications, adhesively bonded assemblies have gained an increasing interest in the industry due to several advantages over welding, riveting and bolting, such as reduction of stress concentrations, lightness, low cost and easy manufacturing. This work is largely concerned to show the effects of the loading rate of the adhesively bonded joints under different speed rates. The tensile tests were conducted at four different rates; static (5mm/min, 50mm/min) and dynamic tests (1m/s, and 10m/s). An attempt was made to determine the damage kinetic and a comparison between the use of aluminium and composite laminate substrates is introduced. Aluminum T6082 and glass/vinylester laminated composite Substrates were used to construct aluminum/aluminum and laminate/laminate specimens. The adhesive used in this study was Araldite 2015. The results showed the effects of the loading rate évolution on the double joint strength. The comparison of the results of static and dynamic tests showed a raise of the strength of the specimens while the load velocity is elevated. In the case of composite substrates double joint lap, the stiffness increased by more than 60% between static and dynamic tests. However, in the case of aluminum substrates, the rigidity improved about 28% from static to moderately high velocity loading. For both aluminum and composite double joint lap, the strength increased by approximately 25% when the tensile velocity is increased from 5 mm/min to 50 mm/min (static tests). Nevertheless, the tensile velocity is extended to 1m/s the strength increased by 13% and 25% respectively for composite and aluminum substrates.

Keywords: adhesive, double lap joints, static and dynamic behavior, tensile tests

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1212 Effect of Filler Metal Diameter on Weld Joint of Carbon Steel SA516 Gr 70 and Filler Metal SFA 5.17 in Submerged Arc Welding SAW

Authors: A. Nait Salah, M. Kaddami

Abstract:

This work describes an investigation on the effect of filler metals diameter to weld joint, and low alloy carbon steel A516 Grade 70 is the base metal. Commercially SA516 Grade70 is frequently used for the manufacturing of pressure vessels, boilers and storage tank, etc. In fabrication industry, the hardness of the weld joint is between the important parameters to check, after heat treatment of the weld. Submerged arc welding (SAW) is used with two filler metal diameters, and this solid wire electrode is used for SAW non-alloy and for fine grain steels (SFA 5.17). The different diameters were selected (Ø = 2.4 mm and Ø = 4 mm) to weld two specimens. Both specimens were subjected to the same preparation conditions, heat treatment, macrograph, metallurgy micrograph, and micro-hardness test. Samples show almost similar structure with highest hardness. It is important to indicate that the thickness used in the base metal is 22 mm, and all specifications, preparation and controls were according to the ASME section IX. It was observed that two different filler metal diameters performed on two similar specimens demonstrated that the mechanical property (hardness) increases with decreasing diameter. It means that even the heat treatment has the same effect with the same conditions, the filler metal diameter insures a depth weld penetration and better homogenization. Hence, the SAW welding technique mentioned in the present study is favorable to implicate for the industry using the small filler metal diameter.

Keywords: ASME, base metal, micro-hardness test, submerged arc welding

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1211 The Curvature of Bending Analysis and Motion of Soft Robotic Fingers by Full 3D Printing with MC-Cells Technique for Hand Rehabilitation

Authors: Chaiyawat Musikapan, Ratchatin Chancharoen, Saknan Bongsebandhu-Phubhakdi

Abstract:

For many recent years, soft robotic fingers were used for supporting the patients who had survived the neurological diseases that resulted in muscular disorders and neural network damages, such as stroke and Parkinson’s disease, and inflammatory symptoms such as De Quervain and trigger finger. Generally, the major hand function is significant to manipulate objects in activities of daily living (ADL). In this work, we proposed the model of soft actuator that manufactured by full 3D printing without the molding process and one material for use. Furthermore, we designed the model with a technique of multi cavitation cells (MC-Cells). Then, we demonstrated the curvature bending, fluidic pressure and force that generated to the model for assistive finger flexor and hand grasping. Also, the soft actuators were characterized in mathematics solving by the length of chord and arc length. In addition, we used an adaptive push-button switch machine to measure the force in our experiment. Consequently, we evaluated biomechanics efficiency by the range of motion (ROM) that affected to metacarpophalangeal joint (MCP), proximal interphalangeal joint (PIP) and distal interphalangeal joint (DIP). Finally, the model achieved to exhibit the corresponding fluidic pressure with force and ROM to assist the finger flexor and hand grasping.

Keywords: biomechanics efficiency, curvature bending, hand functional assistance, multi cavitation cells (MC-Cells), range of motion (ROM)

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1210 Clinical and Structural Differences in Knee Osteoarthritis with/without Synovial Hypertrophy

Authors: Gi-Young Park, Dong Rak Kwon, Sung Cheol Cho

Abstract:

Objective: The synovium is known to be involved in many pathological characteristic processes. Also, synovitis is common in advanced osteoarthritis. We aimed to evaluate the clinical, radiographic, and ultrasound findings in patients with knee osteoarthritis and to compare the clinical and imaging findings between knee osteoarthritis with and without synovial hypertrophy confirmed by ultrasound. Methods: One hundred knees (54 left, 46 right) in 95 patients (64 women, 31 men; mean age, 65.9 years; range, 43-85 years) with knee osteoarthritis were recruited. The Visual Analogue Scale (VAS) was used to assess the intensity of knee pain. The severity of knee osteoarthritis was classified according to Kellgren and Lawrence's (K-L) grade on a radiograph. Ultrasound examination was performed by a physiatrist who had 24 years of experience in musculoskeletal ultrasound. Ultrasound findings, including the thickness of joint effusion in the suprapatellar pouch, synovial hypertrophy, infrapatellar tendinosis, meniscal tear or extrusion, and Baker cyst, were measured and detected. The thickness of knee joint effusion was measured at the maximal anterior-posterior diameter of fluid collection in the suprapatellar pouch. Synovial hypertrophy was identified as the soft tissue of variable echogenicity, which is poorly compressible and nondisplaceable by compression of an ultrasound transducer. The knees were divided into two groups according to the presence of synovial hypertrophy. The differences in clinical and imaging findings between the two groups were evaluated by independent t-test and chi-square test. Results: Synovial hypertrophy was detected in 48 knees of 100 knees on ultrasound. There were no significant differences in demographic parameters and VAS score except in sex between the two groups (P<0.05). Medial meniscal extrusion and tear were significantly more frequent in knees with synovial hypertrophy than those in knees without synovial hypertrophy. K-L grade and joint effusion thickness were greater in patients with synovial hypertrophy than those in patients without synovial hypertrophy (P<0.05). Conclusion: Synovial hypertrophy in knee osteoarthritis was associated with greater suprapatellar joint effusion and higher K-L grade and maybe a characteristic ultrasound feature of late knee osteoarthritis. These results suggest that synovial hypertrophy on ultrasound can be regarded as a predictor of rapid progression in patients with knee osteoarthritis.

Keywords: knee osteoarthritis, synovial hypertrophy, ultrasound, K-L grade

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1209 Traditional and New Residential Architecture in the Approach of Sustainability in the Countryside after the Earthquake

Authors: Zeynep Tanriverdi̇

Abstract:

Sustainable architecture is a design approach that provides healthy, comfortable, safe, clean space production as well as utilizes minimum resources for efficient and economical use of natural resources and energy. Traditional houses located in rural areas are sustainable structures built at the design and implementation stage in accordance with the climatic environmental data of the region and also effectively using natural energy resources. The fact that these structures are located in an earthquake geography like Türkiye brings their earthquake resistance to the agenda. Since the construction of these structures, which contain the architectural and technological cultural knowledge of the past, is shaped according to the characteristics of the regions where they are located, their resistance to earthquakes also differs. Analyses in rural areas after the earthquake show that there are light-damaged structures that can survive, severely damaged structures, and completely destroyed structures. In this regard, experts can implement repair, consolidation, and reconstruction applications, respectively. While simple repair interventions are carried out in accordance with the original data in traditional houses that have shown great resistance to earthquakes, reinforcement work blended with new technologies can be applied in damaged structures. In reconstruction work, a wide variety of applications can be seen with the possibilities of modern technologies. In rural areas experiencing earthquakes around the world, there are experimental new housing applications that are renewable, environmentally friendly, and sustainable with modern construction techniques in the light of scientific data. With these new residences, it is aimed to create earthquake-resistant, economical, healthy, and pain-relieving therapy spaces for people whose daily lives have been interrupted by disasters. In this study, the preservation of high earthquake-prone rural areas will be discussed through the knowledge transfer of traditional architecture and also permanent housing practices using new sustainable technologies to improve the area. In this way, it will be possible to keep losses to a minimum with sustainable, reliable applications prepared for the worst aspects of the disaster situation and to establish a link between the knowledge of the past and the new technologies of the future.

Keywords: sustainability, conservation, traditional construction systems and materials, new technologies, earthquake resistance

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1208 Dynamic Analysis of Double Deck Tunnel

Authors: C. W. Kwak, I. J. Park, D. I. Jang

Abstract:

The importance of cost-wise effective application and construction is getting increase due to the surge of traffic volume in the metropolitan cities. Accordingly, the necessity of the tunnel has large section becomes more critical. Double deck tunnel can be one of the most appropriate solutions to the necessity. The dynamic stability of double deck tunnel is essential against seismic load since it has large section and connection between perimeter lining and interim slab. In this study, 3-dimensional dynamic numerical analysis was conducted based on the Finite Difference Method to investigate the seismic behavior of double deck tunnel. Seismic joint for dynamic stability and the mitigation of seismic impact on the lining was considered in the modeling and analysis. Consequently, the mitigation of acceleration, lining displacement and stress were verified successfully.

Keywords: double deck tunnel, interim slab, 3-dimensional dynamic numerical analysis, seismic joint

Procedia PDF Downloads 356
1207 Sustainable Management Practices of International Construction Joint Ventures: A Conceptual Model for Managing Barriers and Risks

Authors: Mershack O. Tetteh, Albert P. C. Chan, Amos Darko, Gabriel Nani

Abstract:

International construction joint ventures (ICJVs) have evolved as an effective approach to sustainable development, given their myriad socio-economic and environmental benefits. Yet, they are not free of barriers and risks. In many studies, it is termed as risks for convenience’s sake. While the barriers and risks continue to affect the success of ICJVs, a systematic and reliable approach for managing them has yet to be developed. This study aims to identify and classify the barriers and risks factors affecting ICJVs through a systematic literature review. Based on a critical review of 54 papers published in peer-reviewed journals from 1990 to 2019, a conceptual framework was proposed for managing the barriers and risks in ICJV operations. The review showed that the barriers can be grouped into six including inter-organizational differences, lack of expertise and confidence, lack of effective planning and strategies, lack of knowledge of ICJV’s fundamentals, conflicts among ICJV entities, and management difficulties. The risks were also categorized into six: policy and political risks, legal risks, financial risks, management risks, project and technical risks, and market risks. The developed model would help practitioners achieve more efficient resource allocation and bring new perspectives for managerial practices in ICJVs. Moreover, it is positioned to alleviate the negligence of previous studies that combined the barriers and risks factors as one checklist.

Keywords: barriers, construction, international construction joint venture, risks, sustainable development

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1206 Optimal Policies in a Two-Level Supply Chain with Defective Product and Price Dependent Demand

Authors: Samira Mohabbatdar, Abbas Ahmadi, Mohsen S. Sajadieh

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This paper deals with a two-level supply chain consisted of one manufacturer and one retailer for single-type product. The demand function of the customers depends on price. We consider an integrated production inventory system where the manufacturer processes raw materials in order to deliver finished product with imperfect quality to the retailer. Then retailer inspects the products and after that delivers perfect products to customers. The proposed model is based on the joint total profit of both the manufacturer and the retailer, and it determines the optimal ordering lot-size, number of shipment and selling price of the retailer. A numerical example is provided to analyse and illustrate the behaviour and application of the model. Finally, sensitivity analysis of the key parameters are presented to test feasibility of the model.

Keywords: supply chain, pricing policy, defective quality, joint economic lot sizing

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1205 The Glycitin and 38 Combination Inhibit the UV-Induced Wrinkle Fomation in Human Primary Fibroblast

Authors: Manh Tin Ho, Phorl Sophors, Ga Young Seo, Young Mee Kim, Youngho Lim, Moonjae Cho

Abstract:

UV radiation in sunlight is one of the most potential factor induced skin ageing and photocarcinogenesis. UV may induce the melanin production and wrinkle formation. Recently, the natural secondary compounds have been reported that had the beneficial protective effects from UV light. In this study, we investigated the effects of two different compounds, glycitin and 38, on human dermal fibroblast. We first only treated the 38 on melanocyte cell to test the proliferation inhibition of 38 on this cell line. Then, we induced the combination of glycitin and 38 on human dermal fibroblast in 48h and investigate the proliferation, collagen production and the metalloproteinase family expression. The 38 alone could inhibit the proliferation of melanocyte which indicated the reduction of melanin production. The combination of glycitin and 38 truly increased the fibroblast proliferation and even they could recover the UV-induced and H2O2-induced damaged fibroblast proliferation. The co-treatment also promoted the collagen IV expression significantly and accelerated the total collagen secretion. In addition, metalloproteinase (MMPs) family such as MMP1, MMP2, MMP7 was down-regulated in transcriptional level. In conclusion, the combination of glycitin and 38 has induced the fibroblast proliferation even when it was damaged by UV exposure and H2O2, whereas augmented collagen production and inhibited the MMPs caused the wrinkle formation and decreased the melanocyte proliferation, suggested an potential UV-protective therapy.

Keywords: UV radiation, wrinkle, ageing, glycitin, dermal fibroblast

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1204 Specific Biomarker Level and Function Outcome Changes in Treatment of Patients with Frozen Shoulder Using Dextrose Prolotherapy Injection

Authors: Nuralam Sam, Irawan Yusuf, Irfan Idris, Endi Adnan

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The most case in the shoulder in the the adult is the frozen shoulder. It make an uncomfortable sensation which disturbance daily activity. The studies of frozen shoulder are still limited. This study used a true experimental pre and post test design with a group design. The participant underwent dextrose prolotherapy injection in the rotator cuff, intraarticular glenohumeral joint, long head tendon biceps, and acromioclavicular joint injections with 15% dextrose, respectively, at week 2, week 4, and week 6. Participants were followed for 12 weeks. The specific biomarker MMP and TIMP, ROM, DASH score were measured at baseline, at week 6, and week 12. The data were analyzed by multivariate analysis (repeated measurement ANOVA, Paired T-Test, and Wilcoxon) to determine the effect of the intervention. The result showed a significant decrease in The Disability of the Arm, Shoulder, and Hand (DASH) score in prolo injection patients in each measurement week (p < 0.05). While the measurement of Range of Motion (ROM), each direction of shoulder motion showed a significant difference in average each week, from week 0 to week 6 (p <0.05).Dextrose prolotherapy injection results give a significant improvement in functional outcome of the shoulder joint, and ROMand did not show significant results in assessing the specific biomarker, MMP-1, and TIMP-1 in tissue repair. This study suggestion an alternative to the use of injection prolotherapy in Frozen shoulder patients, which has fewer side effects and better effectiveness than the use of corticosteroid injections.

Keywords: frozen shoulder, ROM, DASH score, prolotherapy, MMP-1, TIMP-1

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1203 Comparative Analysis of Two Approaches to Joint Signal Detection, ToA and AoA Estimation in Multi-Element Antenna Arrays

Authors: Olesya Bolkhovskaya, Alexey Davydov, Alexander Maltsev

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In this paper two approaches to joint signal detection, time of arrival (ToA) and angle of arrival (AoA) estimation in multi-element antenna array are investigated. Two scenarios were considered: first one, when the waveform of the useful signal is known a priori and, second one, when the waveform of the desired signal is unknown. For first scenario, the antenna array signal processing based on multi-element matched filtering (MF) with the following non-coherent detection scheme and maximum likelihood (ML) parameter estimation blocks is exploited. For second scenario, the signal processing based on the antenna array elements covariance matrix estimation with the following eigenvector analysis and ML parameter estimation blocks is applied. The performance characteristics of both signal processing schemes are thoroughly investigated and compared for different useful signals and noise parameters.

Keywords: antenna array, signal detection, ToA, AoA estimation

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1202 Understanding Human Rights Violations in the Fight against Boko Haram: A Historical Perspective

Authors: Anthony Mpiani

Abstract:

Recent media and NGO reports suggest that human rights violations have been a salient characteristic of the government Joint Task Force (JTF) in the war on Boko Haram. However, there has been relatively scant scholarly engagement with the forms of abuses committed by the JTF against civilians and why such human rights violations occur. The focus of this paper is to analyse the various human rights violations committed by JTF in the war against Boko Haram. Employing a historical approach, it argues that the JTF's human rights violations is shaped by the philosophy of colonial policing in Nigeria. Consequently, the failure of successive post-colonial governments to ideologically transform policing is accountable for the human rights abuses being witnessed in Nigeria today. A philosophical transformation in Nigeria's security forces especially the police and military is a prerequisite for ending human rights abuses in the fight against Boko Haram.

Keywords: colonialism, policing, joint task force, counterinsurgency, Boko Haram, human rights violations

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1201 Ameliorative Effect of Martynia annua Linn. on Collagen-Induced Arthritis via Modulating Cytokines and Oxidative Stress in Mice

Authors: Alok Pal Jain, Santram Lodhi

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Martynia annua Linn. (Martyniaccae) is traditionally used in inflammation and applied locally to tuberculosis glands of camel’s neck. The leaves used topically to bites of venomous insects and wounds of domestic animals. Chemical examination of Martynia annua leaves revealed the presence of glycosides, tannins, proteins, phenols and flavonoids. The present study was aimed to evaluate the anti-arthritic activity of methanolic extract of Martynia annua leaves. Methanolic extract of Martynia annua leaves was tested by using in vivo collagen-induced arthritis mouse model to investigate the anti-rheumatoid arthritis activity. In addition, antioxidant effect of methanolic extract was determined by the estimation of antioxidants level in joint tissues. The severity of arthritis was assessed by arthritis score and edema. Levels of cytokines TNF-α and IL-6, in the joint tissue homogenate were measured using ELISA. A high dose (250 mg/kg) of methanolic extract was significantly reduced the degree of inflammation in mice as compared with reference drug. Antioxidants level and malondialdehyde (MDA) in joint tissue homogenate found significantly (p < 0.05) higher. Methanolic extract at dose of 250 mg/kg modulated the cytokines production and suppressed the oxidative stress in the mice with collagen-induced arthritis. This study suggested that Martynia annua might be alternative herbal medicine for the management of rheumatoid arthritis.

Keywords: Martynia annua, collagen, rheumatoid arthritis, antioxidants

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1200 Joint Replenishment and Heterogeneous Vehicle Routing Problem with Cyclical Schedule

Authors: Ming-Jong Yao, Chin-Sum Shui, Chih-Han Wang

Abstract:

This paper is developed based on a real-world decision scenario that an industrial gas company that applies the Vendor Managed Inventory model and supplies liquid oxygen with a self-operated heterogeneous vehicle fleet to hospitals in nearby cities. We name it as a Joint Replenishment and Heterogeneous Vehicle Routing Problem with Cyclical Schedule and formulate it as a non-linear mixed-integer linear programming problem which simultaneously determines the length of the planning cycle (PC), the length of the replenishment cycle and the dates of replenishment for each customer and the vehicle routes of each day within PC, such that the average daily operation cost within PC, including inventory holding cost, setup cost, transportation cost, and overtime labor cost, is minimized. A solution method based on genetic algorithm, embedded with an encoding and decoding mechanism and local search operators, is then proposed, and the hash function is adopted to avoid repetitive fitness evaluation for identical solutions. Numerical experiments demonstrate that the proposed solution method can effectively solve the problem under different lengths of PC and number of customers. The method is also shown to be effective in determining whether the company should expand the storage capacity of a customer whose demand increases. Sensitivity analysis of the vehicle fleet composition shows that deploying a mixed fleet can reduce the daily operating cost.

Keywords: cyclic inventory routing problem, joint replenishment, heterogeneous vehicle, genetic algorithm

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1199 Redundancy Component Matrix and Structural Robustness

Authors: Xinjian Kou, Linlin Li, Yongju Zhou, Jimian Song

Abstract:

We introduce the redundancy matrix that expresses clearly the geometrical/topological configuration of the structure. With the matrix, the redundancy of the structure is resolved into redundant components and assigned to each member or rigid joint. The values of the diagonal elements in the matrix indicates the importance of the corresponding members or rigid joints, and the geometrically correlations can be shown with the non-diagonal elements. If a member or rigid joint failures, reassignment of the redundant components can be calculated with the recursive method given in the paper. By combining the indexes of reliability and redundancy components, we define an index concerning the structural robustness. To further explain the properties of the redundancy matrix, we cited several examples of statically indeterminate structures, including two trusses and a rigid frame. With the examples, some simple results and the properties of the matrix are discussed. The examples also illustrate that the redundancy matrix and the relevant concepts are valuable in structural safety analysis.

Keywords: Structural Robustness, Structural Reliability, Redundancy Component, Redundancy Matrix

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1198 Pilot-free Image Transmission System of Joint Source Channel Based on Multi-Level Semantic Information

Authors: Linyu Wang, Liguo Qiao, Jianhong Xiang, Hao Xu

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In semantic communication, the existing joint Source Channel coding (JSCC) wireless communication system without pilot has unstable transmission performance and can not effectively capture the global information and location information of images. In this paper, a pilot-free image transmission system of joint source channel based on multi-level semantic information (Multi-level JSCC) is proposed. The transmitter of the system is composed of two networks. The feature extraction network is used to extract the high-level semantic features of the image, compress the information transmitted by the image, and improve the bandwidth utilization. Feature retention network is used to preserve low-level semantic features and image details to improve communication quality. The receiver also is composed of two networks. The received high-level semantic features are fused with the low-level semantic features after feature enhancement network in the same dimension, and then the image dimension is restored through feature recovery network, and the image location information is effectively used for image reconstruction. This paper verifies that the proposed multi-level JSCC algorithm can effectively transmit and recover image information in both AWGN channel and Rayleigh fading channel, and the peak signal-to-noise ratio (PSNR) is improved by 1~2dB compared with other algorithms under the same simulation conditions.

Keywords: deep learning, JSCC, pilot-free picture transmission, multilevel semantic information, robustness

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1197 Preparation and Biological Evaluation of 186/188Re-Chitosan for Radiosynovectomy

Authors: N. Ahmadi, H. Yousefnia, A. Bahrami-Samani

Abstract:

Chitosan is a natural and biodegradable polysaccharide with special characteristic for application in intracavital therapy. 166Ho-chitosan has been reported for the treatment of hepatocellular carcinoma and RSV with promising results. The aim of this study was to prepare 186/188Re-chitosan for radiosynovectomy purposes and investigate the probability of its leakage from the knee joint. 186/188Re was produced by neutron irradiation of the natural rhenium in a research reactor. Chemical processing was performed to obtain (186/188Re)-NaReO4- according to the IAEA manual. A stock solution of chitosan was prepared by dissolving in 1 % acetic acid aqueous solution (10 mg/mL). 1.5 mL of this stock solution was added to the vial containing the activity and the mixture was stirred for 5 min in the room temperature. The radiochemical purity of the complex was checked by the ITLC method, showing the purity of higher than 98%. Distribution of the radiolabeled complex was determined after intra-articular injection into the knees of rats. Excellent retention was observed in the joint with approximately no activity in the other organs.

Keywords: chitosan, leakage, radiosynovectomy, rhenium

Procedia PDF Downloads 307
1196 Effect of Mineral Admixtures on Transport Properties of SCCs Composites: Influence of Mechanical Damage

Authors: Davood Niknezhad, Siham Kamali-Bernard

Abstract:

Concrete durability is one of the most important considerations in the design of new structures in aggressive environments. It is now common knowledge that the transport properties of a concrete, i.e; permeability and chloride diffusion coefficient are important indicators of its durability. The development of microcracking in concrete structures leads to significant permeability and to durability problems as a result. The main objective of the study presented in this paper is to investigate the influence of mineral admixtures and impact of compressive cracks by mechanical uniaxial compression up to 80% of the ultimate strength on transport properties of self-compacting concrete (SCC) manufactured with the eco-materials (metakaolin, fly ash, slag HF). The chloride resistance and binding capacity of the different SCCs produced with the different admixtures in damaged and undamaged state are measured using a chloride migration test accelerated by an external applied electrical field. Intrinsic permeability is measured using the helium gas and one permeameter at constant load. Klinkenberg approach is used for the determination of the intrinsic permeability. Based on the findings of this study, the use of mineral admixtures increases the resistance of SCC to chloride ingress and reduces their permeability. From the impact of mechanical damage, we show that the Gas permeability is more sensitive of concrete damaged than chloride diffusion. A correlation is obtained between the intrinsic permeability and chloride migration coefficient according to the damage variable for the four studied mixtures.

Keywords: SCC, concrete durability, transport properties, gas permeability, chloride diffusion, mechanical damage, mineral admixtures

Procedia PDF Downloads 195
1195 Flood Disaster Prevention and Mitigation in Nigeria Using Geographic Information System

Authors: Dinebari Akpee, Friday Aabe Gaage, Florence Fred Nwaigwu

Abstract:

Natural disasters like flood affect many parts of the world including developing countries like Nigeria. As a result, many human lives are lost, properties damaged and so much money is lost in infrastructure damages. These hazards and losses can be mitigated and reduced by providing reliable spatial information to the generality of the people through about flood risks through flood inundation maps. Flood inundation maps are very crucial for emergency action plans, urban planning, ecological studies and insurance rates. Nigeria experience her worst flood in her entire history this year. Many cities were submerged and completely under water due to torrential rainfall. Poor city planning, lack of effective development control among others contributes to the problem too. Geographic information system (GIS) can be used to visualize the extent of flooding, analyze flood maps to produce flood damaged estimation maps and flood risk maps. In this research, the under listed steps were taken in preparation of flood risk maps for the study area: (1) Digitization of topographic data and preparation of digital elevation model using ArcGIS (2) Flood simulation using hydraulic model and integration and (3) Integration of the first two steps to produce flood risk maps. The results shows that GIS can play crucial role in Flood disaster control and mitigation.

Keywords: flood disaster, risk maps, geographic information system, hazards

Procedia PDF Downloads 189
1194 Estimation of the External Force for a Co-Manipulation Task Using the Drive Chain Robot

Authors: Sylvain Devie, Pierre-Philippe Robet, Yannick Aoustin, Maxime Gautier

Abstract:

The aim of this paper is to show that the observation of the external effort and the sensor-less control of a system is limited by the mechanical system. First, the model of a one-joint robot with a prismatic joint is presented. Based on this model, two different procedures were performed in order to identify the mechanical parameters of the system and observe the external effort applied on it. Experiments have proven that the accuracy of the force observer, based on the DC motor current, is limited by the mechanics of the robot. The sensor-less control will be limited by the accuracy in estimation of the mechanical parameters and by the maximum static friction force, that is the minimum force which can be observed in this case. The consequence of this limitation is that industrial robots without specific design are not well adapted to perform sensor-less precision tasks. Finally, an efficient control law is presented for high effort applications.

Keywords: control, identification, robot, co-manipulation, sensor-less

Procedia PDF Downloads 130
1193 The Influence of Hydrolyzed Cartilage Collagen on General Mobility and Wellbeing of an Active Population

Authors: Sara De Pelsmaeker, Catarina Ferreira da Silva, Janne Prawit

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Recent studies show that enzymatically hydrolysed collagen is absorbed and distributed to joint tissues, where it has analgesic and active anti-inflammatory properties. Reviews of the associated relevant literature also support this theory. However, these studies are all using hydrolyzed collagen from animal hide or skin. This study looks into the effect of daily supplementation of hydrolyzed cartilage collagen (HCC), which has a different composition. A consumer study was set up using a double-blind placebo-controlled design with a control group using twice a day 0.5gr of maltodextrin and an experimental group using twice 0.5g of HCC, over a trial period of 12 weeks. A follow-up phase of 4 weeks without supplementation was taken into the experiment to investigate the ‘wash-out’ phase. As this consumer study was conducted during the lockdown periods, a specific app was designed to follow up with the participants. The app had the advantage that in this way, the motivation of the participants was enhanced and the drop-out range of participants was lower than normally seen in consumer studies. Participants were recruited via various sports and health clubs across the UK as we targeted a general population of people that considered themselves in good health. Exclusion criteria were ‘not experiencing any medical conditions’ and ‘not taking any prescribed medication’. A minimum requirement was that they regularly engaged in some level of physical activity. The participants had to log the type of activity that they conducted and the duration of the activity. Weekly, participants were providing feedback on their joint health and subjective pain using the validated pain measuring instrument Visual Analogue Scale (VAS). The weekly repoAbstract Public Health and Wellbeing Conferencerting section in the app was designed with simplicity and based on the accuracy demonstrated in previous similar studies to track subjective pain measures of participants. At the beginning of the trial, each participant indicated their baseline on joint pain. The results of this consumer study indicated that HCC significantly improved joint health and subjective pain scores compared to the placebo group. No significant differences were found between different demographic groups (age or gender). The level of activity, going from high intensive training to regular walking, did not significantly influence the effect of the HCC. The results of the wash-out phase indicated that when the participants stopped the HCC supplementation, their subjective pain scores increased again to the baseline. In conclusion, the results gave a positive indication that the daily supplementation of HCC can contribute to the overall mobility and wellbeing of a general active population

Keywords: VAS-score, food supplement, mobility, joint health

Procedia PDF Downloads 135
1192 Crack Growth Life Prediction of a Fighter Aircraft Wing Splice Joint Under Spectrum Loading Using Random Forest Regression and Artificial Neural Networks with Hyperparameter Optimization

Authors: Zafer Yüce, Paşa Yayla, Alev Taşkın

Abstract:

There are heaps of analytical methods to estimate the crack growth life of a component. Soft computing methods have an increasing trend in predicting fatigue life. Their ability to build complex relationships and capability to handle huge amounts of data are motivating researchers and industry professionals to employ them for challenging problems. This study focuses on soft computing methods, especially random forest regressors and artificial neural networks with hyperparameter optimization algorithms such as grid search and random grid search, to estimate the crack growth life of an aircraft wing splice joint under variable amplitude loading. TensorFlow and Scikit-learn libraries of Python are used to build the machine learning models for this study. The material considered in this work is 7050-T7451 aluminum, which is commonly preferred as a structural element in the aerospace industry, and regarding the crack type; corner crack is used. A finite element model is built for the joint to calculate fastener loads and stresses on the structure. Since finite element model results are validated with analytical calculations, findings of the finite element model are fed to AFGROW software to calculate analytical crack growth lives. Based on Fighter Aircraft Loading Standard for Fatigue (FALSTAFF), 90 unique fatigue loading spectra are developed for various load levels, and then, these spectrums are utilized as inputs to the artificial neural network and random forest regression models for predicting crack growth life. Finally, the crack growth life predictions of the machine learning models are compared with analytical calculations. According to the findings, a good correlation is observed between analytical and predicted crack growth lives.

Keywords: aircraft, fatigue, joint, life, optimization, prediction.

Procedia PDF Downloads 133
1191 A Review of Kinematics and Joint Load Forces in Total Knee Replacements Influencing Surgical Outcomes

Authors: Samira K. Al-Nasser, Siamak Noroozi, Roya Haratian, Adrian Harvey

Abstract:

A total knee replacement (TKR) is a surgical procedure necessary when there is severe pain and/or loss of function in the knee. Surgeons balance the load in the knee and the surrounding soft tissue by feeling the tension at different ranges of motion. This method can be unreliable and lead to early failure of the joint. The ideal kinematics and load distribution have been debated significantly based on previous biomechanical studies surrounding both TKRs and normal knees. Intraoperative sensors like VERASENSE and eLibra have provided a method for the quantification of the load indicating a balanced knee. A review of the literature written about intraoperative sensors and tension/stability of the knee was done. Studies currently debate the quantification of the load in medial and lateral compartments specifically. However, most research reported that following a TKR the medial compartment was loaded more heavily than the lateral compartment. In several cases, these results were shown to increase the success of the surgery because they mimic the normal kinematics of the knee. In conclusion, most research agrees that an intercompartmental load differential of between 10 and 20 pounds, where the medial load was higher than the lateral, and an absolute load of less than 70 pounds was ideal. However, further intraoperative sensor development could help improve the accuracy and understanding of the load distribution on the surgical outcomes in a TKR. A reduction in early revision surgeries for TKRs would provide an improved quality of life for patients and reduce the economic burden placed on both the National Health Service (NHS) and the patient.

Keywords: intraoperative sensors, joint load forces, kinematics, load balancing, and total knee replacement

Procedia PDF Downloads 101
1190 Critical Discourse Analysis of President Mamnoon Hussain Speech in the Joint Session of Parliament.

Authors: Saeed Qaisrani

Abstract:

This article briefly reviews the rise of Critical Discourse Analysis about the Pakistani President Mamnoon Hussain speech which delivered in the joint session of Parliament and teases out a detailed analysis of the various critiques that have been levelled at CDA and its practitioners over the last twenty years, both by scholars working within the “critical” paradigm and by other critics. A range of criticisms are discussed which target the underlying premises, the analytical methodology and the disputed areas of reader response and the integration of contextual factors. Controversial issues such as the predominantly negative focus of much CDA scholarship, and the status of CDA as an emergent “intellectual orthodoxy”, are also reviewed. The conclusions offer a summary of the principal criticisms that emerge from this overview, and suggest some ways in which these problems could be attenuated. It also focused on the different views about president speech and how it is presented in the Pakistani print and electronic media.

Keywords: Critical Discourse Analysis, Analytical methodology, Corpus linguistics, Reader response theory, Critical paradigm, Contextualization.

Procedia PDF Downloads 450
1189 Joint Optimization of Carsharing Stations with Vehicle Relocation and Demand Selection

Authors: Jiayuan Wu. Lu Hu

Abstract:

With the development of the sharing economy and mobile technology, carsharing becomes more popular. In this paper, we focus on the joint optimization of one-way station-based carsharing systems. We model the problem as an integer linear program with six elements: station locations, station capacity, fleet size, initial vehicle allocation, vehicle relocation, and demand selection. A greedy-based heuristic is proposed to address the model. Firstly, initialization based on the location variables relaxation using Gurobi solver is conducted. Then, according to the profit margin and demand satisfaction of each station, the number of stations is downsized iteratively. This method is applied to real data from Chengdu, Sichuan taxi data, and it’s efficient when dealing with a large scale of candidate stations. The result shows that with vehicle relocation and demand selection, the profit and demand satisfaction of carsharing systems are increased.

Keywords: one-way carsharing, location, vehicle relocation, demand selection, greedy algorithm

Procedia PDF Downloads 95