Search results for: diffusion effect
10898 The Effect of Grading Characteristics on the Shear Strength and Mechanical Behavior of Granular Classes of Sand-Silt
Authors: Youssouf Benmeriem
Abstract:
Shear strength of sandy soils has been considered as the important parameter to study the stability of different civil engineering structures when subjected to monotonic, cyclic and earthquake loading conditions. The proposed research investigated the effect of grading characteristics on the shear strength and mechanical behavior of granular classes of sands mixed with silt in loose and dense states (Dr = 15% and 90%). The laboratory investigation aimed at understanding the extent or degree at which shear strength of sand-silt mixture soil is affected by its gradation under static loading conditions. For the purpose of clarifying and evaluating the shear strength characteristics of sandy soils, a series of Casagrande shear box tests were carried out on different reconstituted samples of sand-silt mixtures with various gradations. The soil samples were tested under different normal stresses (100, 200 and 300 kPa). The results from this laboratory investigation were used to develop insight into the shear strength response of sand and sand-silt mixtures under monotonic loading conditions. The analysis of the obtained data revealed that the grading characteristics (D10, D50, Cu, ESR, and MGSR) have significant influence on the shear strength response. It was found that shear strength can be correlated to the grading characteristics for the sand-silt mixture. The effective size ratio (ESR) and mean grain size ratio (MGSR) appear as pertinent parameters to predict the shear strength response of the sand-silt mixtures for soil gradation under study.Keywords: grading characteristics, granular classes of sands, mechanical behavior, sand-silt, shear strength
Procedia PDF Downloads 37810897 Informal Green Infrastructure as Mobility Enabler in Informal Settlements of Quito
Authors: Ignacio W. Loor
Abstract:
In the context of informal settlements in Quito, this paper provides evidence that slopes and deep ravines typical of Andean cities, around which marginalized urban communities sit, constitute a platform for green infrastructure that supports mobility for pedestrians in an incremental fashion. This is informally shaped green infrastructure that provides connectivity to other mobility infrastructures such as roads and public transport, which permits relegated dwellers reach their daily destinations and reclaim their rights to the city. This is relevant in that walking has been increasingly neglected as a viable mean of transport in Latin American cities, in favor of rather motorized means, for which the mobility benefits of green infrastructure have remained invisible to policymakers, contributing to the progressive isolation of informal settlements. This research leverages greatly on an ecological rejuvenation programme led by the municipality of Quito and the Andean Corporation for Development (CAN) intended for rehabilitating the ecological functionalities of ravines. Accordingly, four ravines in different stages of rejuvenation were chosen, in order to through ethnographic methods, capture the practices they support to dwellers of informal settlements across different stages, particularly in terms of issues of mobility. Then, by presenting fragments of interviews, description of observed phenomena, photographs and narratives published in institutional reports and media, the production process of mobility infrastructure over unoccupied slopes and ravines, and the roles that this infrastructure plays in the mobility of dwellers and their quotidian practices are explained. For informal settlements, which normally feature scant urban infrastructure, mobility embodies an unfavourable driver for the possibilities of dwellers to actively participate in the social, economic and political dimensions of the city, for which their rights to the city are widely neglected. Nevertheless, informal green infrastructure for mobility provides some alleviation. This infrastructure is incremental, since its features and usability gradually evolves as users put into it knowledge, labour, devices, and connectivity to other infrastructures in different dimensions which increment its dependability. This is evidenced in the diffusion of knowledge of trails and routes of footpaths among users, the implementation of linking stairs and bridges, the improved access by producing public spaces adjacent to the ravines, the illuminating of surrounding roads, and ultimately, the restoring of ecological functions of ravines. However, the perpetuity of this type of infrastructure is also fragile and vulnerable to the course of urbanisation, densification, and expansion of gated privatised spaces.Keywords: green infrastructure, informal settlements, urban mobility, walkability
Procedia PDF Downloads 15010896 Organization Culture: Mediator of Information Technology Competence and IT Governance Effectiveness
Authors: Sonny Nyeko, Moses Niwe
Abstract:
Purpose: This research paper examined the mediation effect of organization culture in the relationship between information technology (IT) competence and IT governance effectiveness in Ugandan public universities. The purpose of the research paper is to examine the role of organizational culture in the relationship between IT competence and IT governance effectiveness. Design/methodology/approach: The paper adopted the MedGraph program, Sobel tests and Kenny and Baron Approach for testing the mediation effects. Findings: It is impeccable that IT competence and organization culture are true drivers of IT governance effectiveness in Ugandan public universities. However, organizational culture reveals partial mediation in the IT competence and IT governance effectiveness relationship. Research limitations/implications: The empirical investigation in this research depends profoundly on public universities. Future research in Ugandan private universities could be undertaken to compare results. Practical implications: To effectively achieve IT governance effectiveness, it means senior management requires IT knowledge which is a vital ingredient of IT competence. Moreover, organizations today ought to adopt cultures that are intended to have them competitive in their businesses, with IT operations not in isolation. Originality/value: Spending thousands of dollars on IT resources in advanced institutes of learning necessitates IT control. Preliminary studies in Ugandan public universities have revealed the ineffective utilization of IT resources. Besides, IT governance issues with IT competence and organization culture remain outstanding. Thus, it’s a new study testing the mediating outcome of organization culture in the association between IT competence and IT governance effectiveness in the Ugandan universities.Keywords: organization culture, IT competence, IT governance, effectiveness, mediating effect, universities, Uganda
Procedia PDF Downloads 12910895 A Transient Coupled Numerical Analysis of the Flow of Magnetorheological Fluids in Closed Domains
Authors: Wael Elsaady, S. Olutunde Oyadiji, Adel Nasser
Abstract:
The non-linear flow characteristics of magnetorheological (MR) fluids in MR dampers are studied via a coupled numerical approach that incorporates a two-phase flow model. The approach couples the Finite Element (FE) modelling of the damper magnetic circuit, with the Computational Fluid Dynamics (CFD) analysis of the flow field in the damper. The two-phase flow CFD model accounts for the effect of fluid compressibility due to the presence of liquid and gas in the closed domain of the damper. The dynamic mesh model included in ANSYS/Fluent CFD solver is used to simulate the movement of the MR damper piston in order to perform the fluid excitation. The two-phase flow analysis is studied by both Volume-Of-Fluid (VOF) model and mixture model that are included in ANSYS/Fluent. The CFD models show that the hysteretic behaviour of MR dampers is due to the effect of fluid compressibility. The flow field shows the distributions of pressure, velocity, and viscosity contours. In particular, it shows the high non-Newtonian viscosity in the affected fluid regions by the magnetic field and the low Newtonian viscosity elsewhere. Moreover, the dependence of gas volume fraction on the liquid pressure inside the damper is predicted by the mixture model. The presented approach targets a better understanding of the complicated flow characteristics of viscoplastic fluids that could be applied in different applications.Keywords: viscoplastic fluid, magnetic FE analysis, computational fluid dynamics, two-phase flow, dynamic mesh, user-defined functions
Procedia PDF Downloads 17010894 The Effect of Exercise, Reflexology and Chrome on Metabolic Syndrome
Authors: F. Arslan, S.D. Guven, A. Özcan, H. Vatansev, Ö. Taşgin
Abstract:
Weight, hypertension and dyslipidemia control and increased physical activity are required for the treatment of metabolic syndrome (METS). The purpose of this study was to investigate the effect of core exercise, reflexology and intake chrome picolinate on METS. This study comprised a twelve-week randomized controlled trial. A total of 25 university workers with metabolic risk factors participated in this study voluntarily. They were randomly divided into three groups: Those undertaking a core exercise program (n=7), reflexology intervention group (n=8) and intake chrome group (n=10). The subjects took part in a core exercise program for one hour per day, three days a week and a reflexology interfered for thirty minutes per day, one days a week and chrome group took chrome picolinate every day in week for twelve weeks. The components of metabolic syndrome were analyzed before and after the completion of all the intervention. There were significant differences at pre-prandial blood glucose in the core exercise group and at systolic blood pressure in chrome group after the twelve week interventions (p < 0.005). While High Density Lipoprotein (HDL) excluding the components of METS decreased after the interventions on the all groups; levels of HDL and the other components of METS decreased in reflexology group. There was a clear response to the twelve-week interventions in terms of METS control. Besides, the reflexology intervention should not be applied to individuals with low HDL levels and core exercise and intake chrome picolinate suggested to improve the components of METS.Keywords: blood pressure, body mass index, exercise, METS, pre-prandial blood glucose
Procedia PDF Downloads 43910893 The Impact of Climate Change on Sustainable Aquaculture Production
Authors: Peyman Mosberian-Tanha, Mona Rezaei
Abstract:
Aquaculture sector is the fastest growing food sector with annual growth rate of about 10%. The sustainability of aquaculture production, however, has been debated mainly in relation to the feed ingredients used for farmed fish. The industry has been able to decrease its dependency on marine-based ingredients in line with policies for more sustainable production. As a result, plant-based ingredients have increasingly been incorporated in aquaculture feeds, especially in feeds for popular carnivorous species, salmonids. The effect of these ingredients on salmonids’ health and performance has been widely studied. In most cases, plant-based diets are associated with varying degrees of health and performance issues across salmonids, partly depending on inclusion levels of plant ingredients and the species in question. However, aquaculture sector is facing another challenge of concern. Environmental challenges in association with climate change is another issue the aquaculture sector must deal with. Data from trials in salmonids subjected to environmental challenges of various types show adverse physiological responses, partly in relation to stress. To date, there are only a limited number of studies reporting the interactive effects of adverse environmental conditions and dietary regimens on salmonids. These studies have shown that adverse environmental conditions exacerbate the detrimental effect of plant-based diets on digestive function and health in salmonids. This indicates an additional challenge for the aquaculture sector to grow in a sustainable manner. The adverse environmental conditions often studied in farmed fish is the change in certain water quality parameters such as oxygen and/or temperature that are typically altered in response to climate change and, more specifically, global warming. In a challenge study, we observed that the in the fish fed a plant-based diet, the fish’s ability to absorb dietary energy was further reduced when reared under low oxygen level. In addition, gut health in these fish was severely impaired. Some other studies also confirm the adverse effect of environmental challenge on fish’s gut health. These effects on the digestive function and gut health of salmonids may result in less resistance to diseases and weaker performance with significant economic and ethical implications. Overall, various findings indicate the multidimensional negative effects of climate change, as a major environmental issue, in different sectors, including aquaculture production. Therefore, a comprehensive evaluation of different ways to cope with climate change is essential for planning more sustainable strategies in aquaculture sector.Keywords: aquaculture, climate change, sustainability, salmonids
Procedia PDF Downloads 18010892 Sustainable and Efficient Recovery of Polyhydroxyalkanoate Polymer from Cupriavidus necator Using Environment Friendly Solvents
Authors: Geeta Gahlawat, Sanjeev Kumar Soni
Abstract:
An imprudent use of environmentally hazardous petrochemical-based plastics and limited availability of fossil fuels have provoked research interests towards production of biodegradable plastics - polyhydroxyalkanoate (PHAs). However, the industrial application of PHAs based products is primarily restricted by their high cost of recovery and extraction protocols. Moreover, solvents used for the extraction and purification are toxic and volatile which causes adverse environmental hazards. Development of efficient downstream recovery strategies along with utilization of non-toxic solvents will accelerate their commercialization. In this study, various extraction strategies were designed for sustainable and cost-effective recovery of PHAs from Cupriavidus necator using non-toxic environment friendly solvents viz. 1,2-propylene carbonate, ethyl acetate, isoamyl alcohol, butyl acetate. The effect of incubation time i.e. 10, 30 and 50 min and temperature i.e. 60, 80, 100, 120°C was tested to identify the most suitable solvent. PHAs extraction using a recyclable solvent, 1,2 propylene carbonate, showed the highest recovery yield (90%) and purity (93%) at 120°C and 30 min incubation. Ethyl acetate showed the better capacity to recover PHAs from cells than butyl acetate. Extraction with ethyl acetate exhibited high recovery yield and purity of 96% and 92%, respectively at 100°C. Effect of non-toxic surfactant such as linear alkylbenzene sulfonic acid (LAS) was also studied at 40, 60 and 80°C, and detergent pH range of 3.0, 5.0, 7.0 and 9.0 for the extraction of PHAs from the cells. LAS gave highest yield of 86% and purity of 88% at temperature 80°C and 5.0 pH.Keywords: polyhydroxyalkanoates, Cupriavidus necator, extraction, recovery yield
Procedia PDF Downloads 50110891 The Effect of Physical Guidance on Learning a Tracking Task in Children with Cerebral Palsy
Authors: Elham Azimzadeh, Hamidollah Hassanlouei, Hadi Nobari, Georgian Badicu, Jorge Pérez-Gómez, Luca Paolo Ardigò
Abstract:
Children with cerebral palsy (CP) have weak physical abilities and their limitations may have an effect on performing everyday motor activities. One of the most important and common debilitating factors in CP is the malfunction in the upper extremities to perform motor skills and there is strong evidence that task-specific training may lead to improve general upper limb function among this population. However, augmented feedback enhances the acquisition and learning of a motor task. Practice conditions may alter the difficulty, e.g., the reduced frequency of PG could be more challenging for this population to learn a motor task. So, the purpose of this study was to investigate the effect of physical guidance (PG) on learning a tracking task in children with cerebral palsy (CP). Twenty-five independently ambulant children with spastic hemiplegic CP aged 7-15 years were assigned randomly to five groups. After the pre-test, experimental groups participated in an intervention for eight sessions, 12 trials during each session. The 0% PG group received no PG; the 25% PG group received PG for three trials; the 50% PG group received PG for six trials; the 75% PG group received PG for nine trials; and the 100% PG group, received PG for all 12 trials. PG consisted of placing the experimenter's hand around the children's hand, guiding them to stay on track and complete the task. Learning was inferred by acquisition and delayed retention tests. The tests involved two blocks of 12 trials of the tracking task without any PG being performed by all participants. They were asked to make the movement as accurate as possible (i.e., fewer errors) and the number of total touches (errors) in 24 trials was calculated as the scores of the tests. The results showed that the higher frequency of PG led to more accurate performance during the practice phase. However, the group that received 75% PG had significantly better performance compared to the other groups in the retention phase. It is concluded that the optimal frequency of PG played a critical role in learning a tracking task in children with CP and likely this population may benefit from an optimal level of PG to get the appropriate amount of information confirming the challenge point framework (CPF), which state that too much or too little information will retard learning a motor skill. Therefore, an optimum level of PG may help these children to identify appropriate patterns of motor skill using extrinsic information they receive through PG and improve learning by activating the intrinsic feedback mechanisms.Keywords: cerebral palsy, challenge point framework, motor learning, physical guidance, tracking task
Procedia PDF Downloads 6510890 Effect of Eight Weeks Aerobic Training with Purslane Seeds on Peroxidant and Antioxidants Indicators in Women with Type2 Diabetes
Authors: Shima Dehghan
Abstract:
Aim: imbalance between antioxidant defensive system and increasing production of free radicals caused oxidative stress that can be rolled in cellular damage and occurring some of diseases such as diabetes. The aim of current study was to investigate the effect of eight weeks aerobic training on peroxidant and antioxidants indicators in women with type2 diabetes. Methodology: thirty two inactive women with type 2 diabetes were randomly assigned into four groups: 1. control, 2. Aerobic training, 3. Purslane seed and 4. Aerobic training + Purslane seed groups. Subjects were asked to accomplish eight weeks aerobic training (50 min aerobic exercise, 3 days/week, for to achieve 65-75% maximum of heart rate). Also, subjects in certain groups received purslane seeds for eight weeks. Blood samples were obtained in two sets (one session and after 8 weeks). Data was analyzed using one way ANOVA. A significant difference was accepted at p < 0/05 level. Results: After eight weeks of aerobic training with purslane seeds supplementation, malon dyaldehyde (MDA) concentration in training group were significantly decreased (p < 0/000), but A difference significant was not found in control group. Superoxide dismutase (SOD) and catalase (CAT) concentrations in training group were significantly increased (p < 0/000), while difference significant wasnot found in control group. Conclusion: The finding of the current study indicates that disciplined aerobic training with purslane seeds supplementation can be caused improvement in peroxidant/antioxidant balance in women with type2 diabetes.Keywords: aerobic training, purslane seed, peroxidant/antioxidant balance, diabetes2
Procedia PDF Downloads 38910889 Flexural Properties of Typha Fibers Reinforced Polyester Composite
Authors: Sana Rezig, Yosr Ben Mlik, Mounir Jaouadi, Foued Khoffi, Slah Msahli, Bernard Durand
Abstract:
Increasing interest in environmental concerns, natural fibers are once again being considered as reinforcements for polymer composites. The main objective of this study is to explore another natural resource, Typha fiber; which is renewable without production cost and available abundantly in nature. The aim of this study was to study the flexural properties of composite resin with and without reinforcing Typha leaf and stem fibers. The specimens were made by the hand-lay-up process using polyester matrix. In our work, we focused on the effect of various treatment conditions (sea water, alkali treatment and a combination of the two treatments), as a surface modifier, on the flexural properties of the Typha fibers reinforced polyester composites. Moreover, weight ratio of Typha leaf or stem fibers was investigated. Besides, both fibers from leaf and stem of Typha plant were used to evaluate the reinforcing effect. Another parameter, which is reinforcement structure, was investigated. In fact, a first composite was made with air-laid nonwoven structure of fibers. A second composite was with a mixture of fibers and resin for each kind of treatment. Results show that alkali treatment and combined process provided better mechanical properties of composites in comparison with fiber treated by sea water. The fiber weight ratio influenced the flexural properties of composites. Indeed, a maximum value of flexural strength of 69.8 and 62,32 MPa with flexural modulus of 6.16 and 6.34 GPawas observed respectively for composite reinforced with leaf and stem fibers for 12.6 % fiber weight ratio. For the different treatments carried out, the treatment using caustic soda, whether alone or after retting seawater, show the best results because it improves adhesion between the polyester matrix and the fibers of reinforcement. SEM photographs were made to ascertain the effects of the surface treatment of the fibers. By varying the structure of the fibers of Typha, the reinforcement used in bulk shows more effective results as that used in the non-woven structure. In addition, flexural strength rises with about (65.32 %) in the case of composite reinforced with a mixture of 12.6% leaf fibers and (27.45 %) in the case of a composite reinforced with a nonwoven structure of 12.6 % of leaf fibers. Thus, to better evaluate the effect of the fiber origin, the reinforcing structure, the processing performed and the reinforcement factor on the performance of composite materials, a statistical study was performed using Minitab. Thus, ANOVA was used, and the patterns of the main effects of these parameters and interaction between them were established. Statistical analysis, the fiber treatment and reinforcement structure seem to be the most significant parameters.Keywords: flexural properties, fiber treatment, structure and weight ratio, SEM photographs, Typha leaf and stem fibers
Procedia PDF Downloads 41210888 Significant Factor of Magnetic Resonance for Survival Outcome in Rectal Cancer Patients Following Neoadjuvant Combined Chemotherapy and Radiation Therapy: Stratification of Lateral Pelvic Lymph Node
Authors: Min Ju Kim, Beom Jin Park, Deuk Jae Sung, Na Yeon Han, Kichoon Sim
Abstract:
Purpose: The purpose of this study is to determine the significant magnetic resonance (MR) imaging factors of lateral pelvic lymph node (LPLN) on the assessment of survival outcomes of neoadjuvant combined chemotherapy and radiation therapy (CRT) in patients with mid/low rectal cancer. Materials and Methods: The institutional review board approved this retrospective study of 63 patients with mid/low rectal cancer who underwent MR before and after CRT and patient consent was not required. Surgery performed within 4 weeks after CRT. The location of LPLNs was divided into following four groups; 1) common iliac, 2) external iliac, 3) obturator, and 4) internal iliac lymph nodes. The short and long axis diameters, numbers, shape (ovoid vs round), signal intensity (homogenous vs heterogenous), margin (smooth vs irregular), and diffusion-weighted restriction of LPLN were analyzed on pre- and post-CRT images. For treatment response using size, lymph node groups were defined as group 1) short axis diameter ≤ 5mm on both MR, group 2) > 5mm change into ≤ 5mm after CRT, and group 3) persistent size > 5mm before and after CRT. Clinical findings were also evaluated. The disease-free survival and overall survival rate were evaluated and the risk factors for survival outcomes were analyzed using cox regression analysis. Results: Patients in the group 3 (persistent size >5mm) showed significantly lower survival rates than the group 1 and 2 (Disease-free survival rates of 36.1% and 78.8, 88.8%, p < 0.001). The size response (group 1-3), multiplicity of LPLN, the level of carcinoembryonic antigen (CEA), patient’s age, T and N stage, vessel invasion, perineural invasion were significant factors affecting disease-free survival rate or overall survival rate using univariate analysis (p < 0.05). The persistent size (group 3) and multiplicity of LPLN were independent risk factors among MR imaging features influencing disease-free survival rate (HR = 10.087, p < 0.05; HR = 4.808, p < 0.05). Perineural invasion and T stage were shown as independent histologic risk factors (HR = 16.594, p < 0.05; HR = 15.891, p < 0.05). Conclusion: The persistent size greater than 5mm and multiplicity of LPLN on both pre- and post-MR after CRT were significant MR factors affecting survival outcomes in the patients with mid/low rectal cancer.Keywords: rectal cancer, MRI, lymph node, combined chemoradiotherapy
Procedia PDF Downloads 14010887 Worldwide Prosperity Through Democracy: A Cross-country Examination of the Impact of Democratization on Human Development from 1990
Authors: Martin Plener
Abstract:
Developmental and democratization research has a long tradition of focusing on the relationship between democratization and economic development. However, recent studies have shown that economic development is not adequate to measure the actual living conditions of civilian people. In consequence, it is unclear if a democratization process helps to improve people’s quality of life. This work addresses this issue by investigating the influence of democratization on the Human Development Index (HDI) created by the United Nations. The main objective is to study the relationship between democracy and human development and whether democratization positively impacts the living conditions of the population over time. The main mechanism which supports a positive impact is that democratic structures promote participation and political involvement of people from all social classes resulting in a better articulation of interests and thus accountability to the government. To study this issue, a panel regression with Fixed-Effects is conducted. By that, it is examined if democracy has a positive impact on the HDI (Hypothesis 1) and secondly if the same effect weakens in more developed democracies compared to less developed democracies (Hypothesis 2). The results do not reveal a direct positive relationship between the democratization of a country and its development of the HDI, not supporting H1 which denies the first hypothesis. In contrast to the assumption of H2, the effect of democratization on human development seems to be negatively correlated in countries in which democracy is barely developed. Therefore, both hypotheses must be discarded. The results indicate rather a positive correlation between economic development on human development. Therefore, the impact of democracy on the well-being of countries’ citizens needs to be reinvestigated in order to create a better understanding of how improved human development can be achieved.Keywords: democracy, human development, modernization theory, HDI, TSCS
Procedia PDF Downloads 7110886 Anti-Viral Activity of Ethanolic Extract Derived from Chlorella sp. AARL G049 on Inhibition of Dengue Virus Serotype 2 Infection in vitro
Authors: Suthida Panwong, Jeeraporn Pekkoh, Yingmanee Tragoolpua, Aussara Panya
Abstract:
Dengue virus (DENV) infection is a major public health problem in many countries, especially in tropical and subtropical countries. DENV infection causes dengue fever that can progress to serious conditions of dengue hemorrhagic fever (DHF) or dengue shock syndrome (DSS), relevant to a high risk of mortality. However, there are no effective treatments available against the manifestation and fatalities. Currently, natural extracts have been widely used for the treatment of infectious diseases due to their safety, non-accumulation in the body, or lower side effects. Chlorella spp. is a microalgae with anti-viral activity, but there is not much report to support its ability to inhibit DENV infection. Thus, this study aimed to investigate the inhibitory effect of ethanolic extract from Chlorella sp. AARL G049, which was explored in Thailand on inhibition of DENV-2 infection. The inhibitory effect on viral infection was assessed using a foci-forming assay (FFA), which revealed that a concentration of 125 µg/mL could inhibit viral infection in Vero cells by 75.45±8.06% when treated at the same time as DENV-2 infection. Moreover, the extract at an equal concentration effectively reduced viral protein synthesis by 90.51±5.48% when assessed in human cell lines using enzyme-linked immunosorbent assay (ELISA). Concordantly, the number of infected cells after treatment was reduced as measured by immunofluorescent assay (IFA). Therefore, the finding of this study supports the potential use of Chlorella sp. extract to suppress DENV infection.Keywords: viral infection, flavivirus, treatment, natural extract
Procedia PDF Downloads 1810885 The Readiness of Bodies Corporate in South Africa for Third Generation Sectional Title Legislation: An Accountancy Perspective
Authors: Leandi Steenkamp
Abstract:
After being in effect since the late 1970s, first generation sectional title legislation in South Africa was completely overhauled in recent years into what is now commonly referred to as third generation sectional title legislation. The original Sectional Titles Act was split into three separate statutes, namely the Sectional Titles Schemes Management Act No. 8 of 2011, the Sectional Titles Amendment Act No. 33 of 2013 and the Community Schemes Ombud Service Act No. 9 of 2011, with various Regulations detailing how the different acts should be applied in practice. Even though some of the changes effected by the new legislation is simply technical adjustments and replications of the original first generation legislation, the new acts introduce a number of significant changes that will have an effect on accountancy and financial management aspects of sectional title schemes in future. No academic research has been undertaken on third generation sectional title legislation in South Africa from an accountancy and financial management perspective as yet. The aim of this paper is threefold: Firstly, to discuss the findings of a literature review on the new third generation sectional title legislation, with specific reference to accountancy-related aspects. Secondly, the empirical findings of accountancy-related aspects from the results of a quantitative study on a sample of bodies corporate will be discussed. The sample of bodies corporate was selected from four different municipal areas in South Africa. Specific reference will be made to the readiness of bodies corporate regarding the provisions of the new legislation. Thirdly, practical recommendations will be made on how bodies corporate can prepare for the new legislative aspects, and further research opportunities in this regard will be discussed.Keywords: accountancy, body corporate, sectional title, third generation sectional title legislation
Procedia PDF Downloads 29810884 The Effect of Photochemical Smog on Respiratory Health Patients in Abuja Nigeria
Authors: Christabel Ihedike, John Mooney, Monica Price
Abstract:
Summary: This study aims to critically evaluate effect of photochemical smog on respiratory health in Nigeria. Cohort of chronic obstructive pulmonary disease (COPD) patients was recruited from two large hospitals in Abuja Nigeria. Respiratory health questionnaires, daily diaries, dyspnoea scale and lung function measurement were used to obtain health data and investigate the relationship with air quality data (principally ozone, NOx and particulate pollution). Concentrations of air pollutants were higher than WHO and Nigerian air quality standard. The result suggests a correlation between measured air quality and exacerbation of respiratory illness. Introduction: Photochemical smog is a significant health challenge in most cities and its effect on respiratory health is well acknowledged. This type of pollution is most harmful to the elderly, children and those with underlying respiratory disease. This study aims to investigate impact of increasing temperature and photo-chemically generated secondary air pollutants on respiratory health in Abuja Nigeria. Method and Result: Health data was collected using spirometry to measure lung function on routine attendance at the clinic, daily diaries kept by patients and information obtained using respiratory questionnaire. Questionnaire responses (obtained using an adapted and internally validated version of St George’s Hospital Respiratory Questionnaire), shows that ‘time of wheeze’ showed an association with participants activities: 30% had worse wheeze in the morning: 10% cannot shop, 15% take long-time to get washed, 25% walk slower, 15% if hurry have to stop and 5% cannot take-bath. There was also a decrease in Forced expiratory volume in the first second and Forced Vital Capacity, and daily change in the afternoon–morning may be associated with the concentration level of pollutants. Also, dyspnoea symptoms recorded that 60% of patients were on grade 3, 25% grade 2 and 15% grade 1. Daily frequency of the number of patients in the cohort that cough /brought sputum is 78%. Air pollution in the city is higher than Nigerian and WHO standards with NOx and PM10 concentrations of 693.59ug/m-3 and 748ugm-3 being measured respectively. The result shows that air pollution may increase occurrence and exacerbation of respiratory disease. Conclusion: High temperature and local climatic conditions in urban Nigeria encourages formation of Ozone, the major constituent of photochemical smog, resulting also in the formation of secondary air pollutants associated with health challenges. In this study we confirm the likely potency of the pattern of secondary air pollution in exacerbating COPD symptoms in vulnerable patient group in urban Nigeria. There is need for better regulation and measures to reduce ozone, particularly when local climatic conditions favour development of photochemical smog in such settings. Climate change and likely increasing temperatures add impetus and urgency for better air quality standards and measures (traffic-restrictions and emissions standards) in developing world settings such as Nigeria.Keywords: Abuja-Nigeria, effect, photochemical smog, respiratory health
Procedia PDF Downloads 21810883 Growth and Yield Response of an Indian Wheat Cultivar (HD 2967) to Ozone and Water Stress in Open-Top Chambers with Emphasis on Its Antioxidant Status, Photosynthesis and Nutrient Allocation
Authors: Annesha Ghosh, S. B. Agrawal
Abstract:
Agricultural sector is facing a serious threat due to climate change and exacerbation of different atmospheric pollutants. Tropospheric ozone (O₃) is considered as a dynamic air pollutant imposing substantial phytotoxicity to natural vegetations and agriculture worldwide. Naturally, plants are exposed to different environmental factors and their interactions. Amongst such interactions, studies related to O₃ and water stress are still rare. In the present experiment, wheat cultivar HD2967 were grown in open top chambers (OTC) under two O₃ concentration; ambient O₃ level (A) and elevated O₃ (E) (ambient + 20 ppb O₃) along with two different water supply; well-watered (W) and 50% water stress conditions (WS), with an aim to assess the individual and interactive effect of two most prevailing stress factors in Indo-Gangetic Plains of India. Exposure to elevated O₃ dose caused early senescence symptoms and reduction in growth and biomass of the test cultivar. The adversity was more pronounced under the combined effect of EWS. Significant reduction of stomatal conductance (gs) and assimilation rate were observed under combined stress condition compared to the control (AW). However, plants grown under individual stress conditions displayed higher gs, biomass, and antioxidant defense mechanism compared to the plants grown under the presence of combined stresses. Higher induction in most of the enzyme activities of catalase (CAT), ascorbate peroxidase (APX), glutathione reductase (GR), peroxidase (POD) and superoxide dismutase (SOD) was displayed by HD 2967 under EW while, under the presence of combined stresses (EWS), a moderate increment of APX and CAT activity was observed only at its vegetative phase. Furthermore, variations in nutrient uptake and redistribution to different plants parts were also observed in the present study. Reduction in water availability has checked nutrient uptake (N, K, P, Ca, Cu, Mg, Zn) in above-ground parts (leaf) and below-ground parts (root). On the other hand, carbon (C) accumulation with subsequent C-N ratio was observed to be higher in the leaves under EWS. Such major nutrient check and limitation in carbon fixation due to lower gs under combined stress conditions might have weakened the defense mechanisms of the test cultivar. Grain yield was significantly reduced under EWS followed by AWS and EW as compared to their control, exhibiting an additive effect on the grain yield.Keywords: antioxidants, open-top chambers, ozone, water stress, wheat, yield
Procedia PDF Downloads 11110882 Study on the Changes in Material Strength According to Changes in Forming Methods in Hot-Stamping Process
Authors: Yong-Jun Jeon, Hyung-Pil Park, Min-Jae Song, Baeg-Soon Cha
Abstract:
Following the recent trend of having increased demand in producing lighter-weight car bodies for improvement of automobile safety and gas mileage, there is a forming method that makes use of hot-stamping technique, which satisfies all conditions mentioned above. Hot-stamping is a forming technique with advantages of excellent formability, good dimensional precision and others since it is a process in which steel plates are heated up to temperatures of at least approximately 900°C after which forming is conducted in die at room temperature followed by rapid cooling. In addition, it has characteristics of allowing for improvement in material strength through achievement of quenching effect by having simultaneous forming and rapid cooling of material of high temperatures. However, there is insufficient information on the changes in material strength according to changes in material temperature with regards to material heating method and forming process in hot-stamping. Accordingly, this study aims to design and press die for T-type product of the scale models of the center pillar and to understand the changes in material strength in relation to changes in forming methods of hot-stamping process. Thus in order to understand the changes in material strength due to quenching effect among the hot-stamping process, material strength and material forming precision were to be studied while varying the forming and forming method when forming. For test methods, material strength was observed by using boron steel that has boron additives, which was heated up to 950°C, after which it was transferred to a die and was cooled down to material temperature of 400°C followed by air cooling process. During the forming and cooling process here, experiment was conducted with forming parameters of 2 holding rates and 3 flange heating rates wherein changing appearance in material strength according to changes forming method were observed by verifying forming strength and forming precision for each of the conditions.Keywords: hot-stamping, formability, quenching, forming, press die, forming methods
Procedia PDF Downloads 45710881 Self-Care Behavior and Performance Level Associated with Algerian Chronically Ill Patients
Authors: S. Aberkane, N. Djabali, S. Fafi, A. Baghezza
Abstract:
Chronic illnesses affect many Algerians. It is possible to investigate the impact of illness representations and coping on quality of life and whether illness representations are indirectly associated with quality of life through their influence on coping. This study aims at investigating the relationship between illness perception, coping strategies and quality of life with chronic illness. Illness perceptions are indirectly associated with the quality of life through their influence on coping mediation. A sample of 316 participants with chronic illness living in the region of Batna, Algeria, has been adopted in this study. A correlation statistical analysis is used to determine the relationship between illness perception, coping strategies, and quality of life. Multiple regression analysis was employed to highlight the predictive ability of the dimensions of illness perception and coping strategies on the dependent variables of quality of life, where mediation analysis is considered in the exploration of the indirect effect significance of the mediator. This study provides insights about the relationship between illness perception, coping strategies and quality of life in the considered sample (r = 0.39, p < 0.01). Therefore, it proves that there is an effect of illness identity perception, external and medical attributions related to emotional role, physical functioning, and mental health perceived, and these were fully mediated by the asking for assistance (c’= 0.04, p < 0.05), the guarding (c’= 0.00, p < 0.05), and the task persistence strategy (c’= 0.05, p < 0.05). The findings imply partial support for the common-sense model of illness representations in a chronic illness population. Directions for future research are highlighted, as well as implications for psychotherapeutic interventions which target unhelpful beliefs and maladaptive coping strategies (e.g., cognitive behavioral therapy).Keywords: chronic illness, coping, illness perception, quality of life, self- regulation model
Procedia PDF Downloads 22010880 Anti-Inflammatory, Analgesic and Antipyretic Activity of Terminalia arjuna Roxb. Extract in Animal Models
Authors: Linda Chularojmontri, Seewaboon Sireeratawong, Suvara Wattanapitayakul
Abstract:
Terminalia arjuna Roxb. (family Combretaceae) is commonly known as ‘Sa maw thet’ in Thai. The fruit is used in traditional medicine as natural mild laxatives, carminative and expectorant. Aim of the study: This research aims to study the anti-inflammatory, analgesic and antipyretic activities of Terminalia arjuna extract by using animal models in comparison to the reference drugs. Materials and Methods: The anti-inflammatory study was conducted by two experimental animal models namely ethyl phenylpropionate (EPP)-induced ear edema and carrageenan-induced paw edema. The study of analgesic activity used two methods of pain induction including acetic acid and heat-induced pain. In addition, the antipyretic activity study was performed by induced hyperthermia with yeast. Results: The results showed that the oral administration of Terminalia arjuna extract possessed acute anti-inflammatory effect in carrageenan-induced paw edema. Terminalia arjuna extract showed the analgesic activity in acetic acid-induced writhing response and heat-induced pain. This indicates its peripheral effect by inhibiting the biosynthesis and/or release of some pain mediators and some mechanism through Central nervous system. Moreover, Terminalia arjuna extract at the dose of 1000 and 1500 mg/kg body weight showed the antipyretic activity, which might be because of the inhibition of prostaglandins. Conclusion: The findings of this study indicated that the Terminalia arjuna extract possesses the anti-inflammatory, analgesic and antipyretic activities in animals.Keywords: analgesic activity, anti-inflammatory activity, antipyretic activity, Terminalia arjuna extract
Procedia PDF Downloads 25910879 Stem Cell Augmentation Therapy for Cardiovascular Risk in Ankylosing Spondylitis: STATIN-as Study
Authors: Ashit Syngle, Nidhi Garg, Pawan Krishan
Abstract:
Objective: Bone marrow derived stem cells, endothelial progenitor cells (EPCs), protect against atherosclerotic vascular damage. However, EPCs are depleted in AS and contribute to the enhanced cardiovascular risk. Statins have a protective effect in CAD and diabetes by enhancing the proliferation, migration and survival of EPCs. Therapeutic potential of augmenting EPCs to treat the heightened cardiovascular risk of AS has not yet been exploited. We aimed to investigate the effect of rosuvastatin on EPCs population and inflammation in AS. Methods: 30 AS patients were randomized to receive 6 months of treatment with rosuvastatin (10 mg/day, n=15) and placebo (n=15) as an adjunct to existing stable anti-rheumatic drugs. EPCs (CD34+/CD133+) were quantified by Flow Cytometry. Inflammatory measures (BASDAI, BASFI, CRP and ESR), pro-inflammatory cytokines (TNF-α, IL-6 and IL-1) and lipids were measured at baseline and after treatment. Results: At baseline, inflammatory measures and pro-inflammatory cytokines were elevated and EPCs depleted among both groups. EPCs increased significantly (p < 0.01) after treatment with rosuvastatin. At 6 months, BASDAI, BASFI, ESR, CRP, TNF-α, and IL-6 improved significantly in rosuvastatin group. Significant negative correlation was observed between EPCs and BASDAI, CRP and IL-6 after rosuvastatin treatment. Conclusion: First study to show that rosuvastatin augments EPCs population in AS. This defines a novel mechanism of rosuvastatin treatment in AS: the augmentation of EPCs with improvement in proinflammatory cytokines and inflammatory disease activity. The augmentation of EPCs by rosuvastatin may provide a novel strategy to prevent cardiovascular events in AS.Keywords: ankylosing spondylitis, Endothelial Progenitor Cells, inflammation, pro-inflammatory cytokines, rosuvastatin
Procedia PDF Downloads 34710878 Environmental Effect on Corrosion Fatigue Behaviors of Steam Generator Forging in Simulated Pressurized Water Reactor Environment
Authors: Yakui Bai, Chen Sun, Ke Wang
Abstract:
An experimental investigation of environmental effect on fatigue behavior in SA508 Gr.3 Cl.2 Steam Generator Forging CAP1400 nuclear power plant has been carried out. In order to simulate actual loading condition, a range of strain amplitude was applied in different low cycle fatigue (LCF) tests. The current American Society of Mechanical Engineers (ASME) design fatigue code does not take full account of the interactions of environmental, loading, and material's factors. A range of strain amplitude was applied in different low cycle fatigue (LCF) tests at a strain rate of 0.01%s⁻¹. A design fatigue model was constructed by taking environmentally assisted fatigue effects into account, and the corresponding design curves were given for the convenience of engineering applications. The corrosion fatigue experiment was performed in a strain control mode in 320℃ borated and lithiated water environment to evaluate the effects of a mixed environment on fatigue life. Stress corrosion cracking (SCC) in steam generator large forging in primary water of pressurized water reactor was also observed. In addition, it is found that the CF life of SA508 Gr.3 Cl.2 decreases with increasing temperature in the water environment. The relationship between the reciprocal of temperature and the logarithm of fatigue life was found to be linear. Through experiments and subsequent analysis, the mechanisms of reduced low cycle fatigue life have been investigated for steam generator forging.Keywords: failure behavior, low alloy steel, steam generator forging, stress corrosion cracking
Procedia PDF Downloads 11510877 Evaluation of the Effect of Nursing Services Provided in a Correctional Institution on the Physical Health Levels and Health Behaviors of Female Inmates
Authors: Şenay Pehli̇van, Gülümser Kublay
Abstract:
Female inmates placed in a Correctional Institution (CI) have more physical health problems than other women and their male counterparts. Thus, they require more health care services in the CI and nursing services in particular. CI nurses also have the opportunity to teach behaviors which will protect and improve their health to these women who are difficult to reach in the community. The aim of this study was to evaluate effect of nursing services provided in a CI on the physical health levels and health behaviors of female inmates. The study has a quasi-experimental design. The study was done in Female Closed CI in Ankara, Turkey. The study was conducted on 30 female inmates. Before the implementation of nursing interventions in the initial phase of the study, female inmates were evaluated in terms of physical health problems and health behavior using forms, a physical examination, medical history, health files (file containing medical information related to prisons) and the Omaha System (OS). Findings obtained from evaluations were grouped and symptoms-findings were expressed with OS diagnosis codes. Knowledge, behavior and status scores of prisoners in relation to health problems were determined. After the implementation of the nursing interventions, female inmates were evaluated in terms of physical health problems and health behavior using OS. The research data were collected using the Female Evaluation Form developed by the researcher and the OS. It was found that knowledge, behavior and status scores of prisoners significantly increased after the implementation of nursing interventions (p < 0.05).Keywords: prison nursing, health promotion and protecting, nursi̇ng servi̇ces, omaha system
Procedia PDF Downloads 25510876 Effect of Plant Growth Regulator on Vegetative Growth and Yield Components of Winter Wheat under Different Levels of Irrigation
Authors: Mohammed Ahmed Alghamdi
Abstract:
Field experiment were carried out to investigate the effect of the plant growth regulator on vegetative growth and yield components of reduced height isogenic lines of the wheat (Triticum aestivum L.) cultivar Mercia. The Field experiment compared the growth regulator response of seven isogenic lines of Mercia. Growth regulators reduced plant height significantly in all lines. Growth regulator decreased total dry matter and grain yield with greatest reduction generally for the control and Rht8 lines. Rht1 was the least affected. There were few significant effects of growth regulator on gas exchange and chlorophyll fluorescence but the trend was for greater values with growth regulator. In this field experiment, a rate of 2.0 l ha-1 applied just before the third node detectable stage under non water stressed and water stressed conditions gave slight increases in yield of up to 14% except for line Rht10 which increased significantly in non-stressed conditions. In the second glasshouse experiment, a rate of 2.5 l ha-1 applied at the start of stem elongation under 30% FC and 100% FC gave reductions in yield up to 16% for the growth regulator and 55% under water stress. In the field experiment, rates of 2.5 and 3.0 l ha-1 applied at the start of stem elongation gave reductions in yield up to 20% mainly through individual seed weight. In the final glasshouse experiment, rates of 2.5 and 3.0 l ha-1 applied at 6 leaves unfolded and 1st node detectable both reduced grain yield.Keywords: growth regulator, irrigation, isogenic lines, yield, winter wheat
Procedia PDF Downloads 45010875 Characterization of Aerosol Droplet in Absorption Columns to Avoid Amine Emissions
Authors: Hammad Majeed, Hanna Knuutila, Magne Hilestad, Hallvard Svendsen
Abstract:
Formation of aerosols can cause serious complications in industrial exhaust gas CO2 capture processes. SO3 present in the flue gas can cause aerosol formation in an absorption based capture process. Small mist droplets and fog formed can normally not be removed in conventional demisting equipment because their submicron size allows the particles or droplets to follow the gas flow. As a consequence of this aerosol based emissions in the order of grams per Nm3 have been identified from PCCC plants. In absorption processes aerosols are generated by spontaneous condensation or desublimation processes in supersaturated gas phases. Undesired aerosol development may lead to amine emissions many times larger than what would be encountered in a mist free gas phase in PCCC development. It is thus of crucial importance to understand the formation and build-up of these aerosols in order to mitigate the problem.Rigorous modelling of aerosol dynamics leads to a system of partial differential equations. In order to understand mechanics of a particle entering an absorber an implementation of the model is created in Matlab. The model predicts the droplet size, the droplet internal variable profiles and the mass transfer fluxes as function of position in the absorber. The Matlab model is based on a subclass method of weighted residuals for boundary value problems named, orthogonal collocation method. The model comprises a set of mass transfer equations for transferring components and the essential diffusion reaction equations to describe the droplet internal profiles for all relevant constituents. Also included is heat transfer across the interface and inside the droplet. This paper presents results describing the basic simulation tool for the characterization of aerosols formed in CO2 absorption columns and gives examples as to how various entering droplets grow or shrink through an absorber and how their composition changes with respect to time. Below are given some preliminary simulation results for an aerosol droplet composition and temperature profiles. Results: As an example a droplet of initial size of 3 microns, initially containing a 5M MEA, solution is exposed to an atmosphere free of MEA. Composition of the gas phase and temperature is changing with respect to time throughout the absorber.Keywords: amine solvents, emissions, global climate change, simulation and modelling, aerosol generation
Procedia PDF Downloads 25710874 Behavior of the RC Slab Subjected to Impact Loading According to the DIF
Authors: Yong Jae Yu, Jae-Yeol Cho
Abstract:
In the design of structural concrete for impact loading, design or model codes often employ a dynamic increase factor (DIF) to impose dynamic effect on static response. Dynamic increase factors that are obtained from laboratory material test results and that are commonly given as a function of strain rate only are quite different from each other depending on the design concept of design codes like ACI 349M-06, fib Model Code 2010 and ACI 370R-14. Because the dynamic increase factors currently adopted in the codes are too simple and limited to consider a variety of strength of materials, their application in practical design is questionable. In this study, the dynamic increase factors used in the three codes were validated through the finite element analysis of reinforced concrete slab elements which were tested and reported by other researcher. The test was intended to simulate a wall element of the containment building in nuclear power plants that is assumed to be subject to impact scenario that the Pentagon experienced on September 11, 2001. The finite element analysis was performed using the ABAQAUS 6.10 and the plasticity models were employed for the concrete, reinforcement. The dynamic increase factors given in the three codes were applied to the stress-strain curves of the materials. To estimate the dynamic increase factors, strain rate was adopted as a parameter. Comparison of the test and analysis was done with regard to perforation depth, maximum deflection, and surface crack area of the slab. Consequently, it was found that DIF has so great an effect on the behavior of the reinforced concrete structures that selection of DIF should be very careful. The result implies that DIF should be provided in design codes in more delicate format considering various influence factors.Keywords: impact, strain rate, DIF, slab elements
Procedia PDF Downloads 28810873 The Effect of Religious Tourist Motivation and Satisfaction on Behavioral Intention
Abstract:
In recent years, the Chaoshan area, a special place located in the southeast of Guangdong province in China, actively protects religious heritage and is developing religious tourism, which is attracting many expatriate Chinese who are coming back for travel and to worship. This paper discussed three questions. Firstly, what is the current situation about the different social background of tourists’ motivation, satisfaction and behavioral intention? Secondly, is there a relationship between the motivation, satisfaction and behavioral intention and the different social backgrounds of tourists? Thirdly, what is the relationship between religious tourists’ motivation, satisfaction and behavioral intention? The research methods use a combination of qualitative analysis and quantitative analysis. Qualitative analysis uses the method of observation and interviews. Convenient sampling technique was used for quantitative analysis. The study showed that the different social backgrounds of tourists’ forms diverse cognition and experiences about religious tourism, and their motivations, satisfaction and behavioral intention as tourists vary. Tourists’ motivation and satisfaction has a positive phase relation. Tourists’ motivation with satisfaction as the intervening variable also has a positive phase effect on tourists’ behavior intention. The result shows that religious tourists’ motivations include experiencing a religious atmosphere, and having a rest and recreation. The result also shows that religious tourists want to travel with their family members and friends. While traveling, religious tourists like to talk with Buddhist monks or nuns. Compared to other tourism types, religious tourists have higher expectations about temple environment, traveling experience, peripheral service and temple management.Keywords: behavioral intension, motivation, religious tourism, satisfaction
Procedia PDF Downloads 31310872 Effect of Online Mindfulness Training to Tertiary Students’ Mental Health: An Experimental Research
Authors: Abigaile Rose Mary R. Capay, Janne Ly Castillon-Gilpo, Sheila A. Javier
Abstract:
The transition to online learning has been a challenging feat on the mental health of tertiary students. This study investigated whether learning mindfulness strategies online would help in improving students’ imagination, conscientiousness, extraversion, agreeableness and emotional stability, as measured by the International Personality Item Pool (IPIP) Big Five Factor Markers, as well as their dispositional mindfulness as measured by the Mindfulness Attention Awareness Scale (MAAS). Fifty-two college students participated in the experiment. The 23 participants assigned to the treatment condition received 6-weekly experiential sessions of online mindfulness training and were advised to follow a daily mindfulness practice, while the 29 participants from the control group only received a 1-hour lecture. Scores were collected at pretest and posttest. Findings show that there was a significant difference in the pretest and posttest scores of students assigned in the treatment group, likewise medium effect sizes in the variables: dispositional mindfulness (t (22) = 2.64, p = 0.015, d = .550), extraversion (t (22) = 2.76, p = 0.011, d = 0.575), emotional stability (t (22) = 2.99, p = 0.007, d = .624), conscientiousness (t (22) = 2.74, p = 0.012, d = .572) and imagination (t (22) = 4.08, p < .001), but not for agreeableness (t (22) = 2.01, p = 0.057, d = .419). No significant differences were observed on the scores of the control group. Educational institutions are recommended to consider teaching basic mindfulness strategies to tertiary students, as a valuable resource in improving their mental health as they navigate through adjustments in online learning.Keywords: mindfulness, school-based interventions, MAAS, IPIP Big Five Markers, experiment
Procedia PDF Downloads 5010871 Evaluation of Initial Graft Tension during ACL Reconstruction Using a Three-Dimensional Computational Finite Element Simulation: Effect of the Combination of a Band of Gracilis with the Former Graft
Authors: S. Alireza Mirghasemi, Javad Parvizi, Narges R. Gabaran, Shervin Rashidinia, Mahdi M. Bijanabadi, Dariush G. Savadkoohi
Abstract:
Background: The anterior cruciate ligament is one of the most frequent ligament to be disrupted. Surgical reconstruction of the anterior cruciate ligament is a common practice to treat the disability or chronic instability of the knee. Several factors associated with success or failure of the ACL reconstruction including preoperative laxity of the knee, selection of the graft material, surgical technique, graft tension, and postoperative rehabilitation. We aimed to examine the biomechanical properties of any graft type and initial graft tensioning during ACL reconstruction using 3-dimensional computational finite element simulation. Methods: In this paper, 3-dimensional model of the knee was constructed to investigate the effect of graft tensioning on the knee joint biomechanics. Four different grafts were compared: 1) Bone-patellar tendon-bone graft (BPTB) 2) Hamstring tendon 3) BPTB and a band of gracilis4) Hamstring and a band of gracilis. The initial graft tension was set as “0, 20, 40, or 60N”. The anterior loading was set to 134 N. Findings: The resulting stress pattern and deflection in any of these models were compared to that of the intact knee. The obtained results showed that the combination of a band of gracilis with the former graft (BPTB or Hamstring) increases the structural stiffness of the knee. Conclusion: Required pretension during surgery decreases significantly by adding a band of gracilis to the proper graft.Keywords: ACL reconstruction, deflection, finite element simulation, stress pattern
Procedia PDF Downloads 29210870 Effect of Three Drying Methods on Antioxidant Efficiency and Vitamin C Content of Moringa oleifera Leaf Extract
Authors: Kenia Martínez, Geniel Talavera, Juan Alonso
Abstract:
Moringa oleifera is a plant containing many nutrients that are mostly concentrated within the leaves. Commonly, the separation process of these nutrients involves solid-liquid extraction followed by evaporation and drying to obtain a concentrated extract, which is rich in proteins, vitamins, carbohydrates, and other essential nutrients that can be used in the food industry. In this work, three drying methods were used, which involved very different temperature and pressure conditions, to evaluate the effect of each method on the vitamin C content and the antioxidant efficiency of the extracts. Solid-liquid extractions of Moringa leaf (LE) were carried out by employing an ethanol solution (35% v/v) at 50 °C for 2 hours. The resulting extracts were then dried i) in a convective oven (CO) at 100 °C and at an atmospheric pressure of 750 mbar for 8 hours, ii) in a vacuum evaporator (VE) at 50 °C and at 300 mbar for 2 hours, and iii) in a freeze-drier (FD) at -40 °C and at 0.050 mbar for 36 hours. The antioxidant capacity (EC50, mg solids/g DPPH) of the dry solids was calculated by the free radical inhibition method employing DPPH˙ at 517 nm, resulting in a value of 2902.5 ± 14.8 for LE, 3433.1 ± 85.2 for FD, 3980.1 ± 37.2 for VE, and 8123.5 ± 263.3 for CO. The calculated antioxidant efficiency (AE, g DPPH/(mg solids·min)) was 2.920 × 10-5 for LE, 2.884 × 10-5 for FD, 2.512 × 10-5 for VE, and 1.009 × 10-5 for CO. Further, the content of vitamin C (mg/L) determined by HPLC was 59.0 ± 0.3 for LE, 49.7 ± 0.6 for FD, 45.0 ± 0.4 for VE, and 23.6 ± 0.7 for CO. The results indicate that the convective drying preserves vitamin C and antioxidant efficiency to 40% and 34% of the initial value, respectively, while vacuum drying to 76% and 86%, and freeze-drying to 84% and 98%, respectively.Keywords: antioxidant efficiency, convective drying, freeze-drying, Moringa oleifera, vacuum drying, vitamin C content
Procedia PDF Downloads 26110869 Drying Shrinkage of Concrete: Scale Effect and Influence of Reinforcement
Authors: Qier Wu, Issam Takla, Thomas Rougelot, Nicolas Burlion
Abstract:
In the framework of French underground disposal of intermediate level radioactive wastes, concrete is widely used as a construction material for containers and tunnels. Drying shrinkage is one of the most disadvantageous phenomena of concrete structures. Cracks generated by differential shrinkage could impair the mechanical behavior, increase the permeability of concrete and act as a preferential path for aggressive species, hence leading to an overall decrease in durability and serviceability. It is of great interest to understand the drying shrinkage phenomenon in order to predict and even to control the strains of concrete. The question is whether the results obtained from laboratory samples are in accordance with the measurements on a real structure. Another question concerns the influence of reinforcement on drying shrinkage of concrete. As part of a global project with Andra (French National Radioactive Waste Management Agency), the present study aims to experimentally investigate the scale effect as well as the influence of reinforcement on the development of drying shrinkage of two high performance concretes (based on CEM I and CEM V cements, according to European standards). Various sizes of samples are chosen, from ordinary laboratory specimens up to real-scale specimens: prismatic specimens with different volume-to-surface (V/S) ratios, thin slices (thickness of 2 mm), cylinders with different sizes (37 and 160 mm in diameter), hollow cylinders, cylindrical columns (height of 1000 mm) and square columns (320×320×1000 mm). The square columns have been manufactured with different reinforcement rates and can be considered as mini-structures, to approximate the behavior of a real voussoir from the waste disposal facility. All the samples are kept, in a first stage, at 20°C and 50% of relative humidity (initial conditions in the tunnel) in a specific climatic chamber developed by the Laboratory of Mechanics of Lille. The mass evolution and the drying shrinkage are monitored regularly. The obtained results show that the specimen size has a great impact on water loss and drying shrinkage of concrete. The specimens with a smaller V/S ratio and a smaller size have a bigger drying shrinkage. The correlation between mass variation and drying shrinkage follows the same tendency for all specimens in spite of the size difference. However, the influence of reinforcement rate on drying shrinkage is not clear based on the present results. The second stage of conservation (50°C and 30% of relative humidity) could give additional results on these influences.Keywords: concrete, drying shrinkage, mass evolution, reinforcement, scale effect
Procedia PDF Downloads 173