Search results for: size control
3652 Infrared Thermography as an Informative Tool in Energy Audit and Software Modelling of Historic Buildings: A Case Study of the Sheffield Cathedral
Authors: Ademuyiwa Agbonyin, Stamatis Zoras, Mohammad Zandi
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This paper investigates the extent to which building energy modelling can be informed based on preliminary information provided by infrared thermography using a thermal imaging camera in a walkthrough audit. The case-study building is the Sheffield Cathedral, built in the early 1400s. Based on an informative qualitative report generated from the thermal images taken at the site, the regions showing significant heat loss are input into a computer model of the cathedral within the integrated environmental solution (IES) virtual environment software which performs an energy simulation to determine quantitative heat losses through the building envelope. Building data such as material thermal properties and building plans are provided by the architects, Thomas Ford and Partners Ltd. The results of the modelling revealed the portions of the building with the highest heat loss and these aligned with those suggested by the thermal camera. Retrofit options for the building are also considered, however, may not see implementation due to a desire to conserve the architectural heritage of the building. Results show that thermal imaging in a walk-through audit serves as a useful guide for the energy modelling process. Hand calculations were also performed to serve as a 'control' to estimate losses, providing a second set of data points of comparison.Keywords: historic buildings, energy retrofit, thermal comfort, software modelling, energy modelling
Procedia PDF Downloads 1703651 Revolutionary Violence and Echoes of the «Thou Shalt Not Kill» Debate: A Tragic Reading of the Class Conflict in Colombia
Authors: Jaime Otavo
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Oscar del Barco, a former member of Los Montoneros, an Argentine guerrilla group of the 1970s, published a letter in 2004 that sparked a heated debate in his country about revolutionary violence. Del Barco, on the subject of «No matarás» (Thou shalt not kill) –as this debate was known– wrote to Sergio Schmucler, his addressee, the following: "There is no 'ideal' that justifies the death of a man. The founding principle of any community is 'Thou shalt not kill'. Thou shalt not kill the man because every man is sacred, and every man is all men".In this paper, the «No matarás» debate will be used to problematize two interconnected ideas that, in Colombia, underpinned the use of revolutionary violence by the guerrilla movements that emerged in the 1970s. On the one hand, an anthropological optimism; on the other, a theological scheme of converting violence into justice. Based on this, two arguments are put forward: 1) that revolutionary violence arose from an ethical-political certainty, namely: the confidence in being on the right side of history (because the violent ones were others), but 2) that its persistence over time made visible a tragic element, that is, that the bipolarity between victim and executioner, good and evil, or friend and foe that is inscribed in the class struggle is a false dilemma for in the context of revolutionary violence –as in the context of Greek tragedy–, no one ever has to make a decision, nor can he do so. For this reason, it is maintained that the fundamental aspect about guerrilla violence in Colombia is that it imposed itself as a violence of negativity which not only exceeded the capacity of the extreme left to control its revolutionary praxis but also exploited the link with the political subjectivation to which it aspired, the proletariat as the gravedigger of the bourgeoisie.Keywords: marxism, social movements, armed struggle, debate thou shalt not kill
Procedia PDF Downloads 823650 Engineered Reactor Components for Durable Iron Flow Battery
Authors: Anna Ivanovskaya, Alexandra E. L. Overland, Swetha Chandrasekaran, Buddhinie S. Jayathilake
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Iron-based redox flow batteries (IRFB) are promising for grid-scale storage because of their low-cost and environmental safety. Earth-abundant iron can enable affordable grid-storage to meet DOE’s target material cost <$20/kWh and levelized cost for storage $0.05/kWh. In conventional redox flow batteries, energy is stored in external electrolyte tanks and electrolytes are circulated through the cell units to achieve electrochemical energy conversions. However, IRFBs are hybrid battery systems where metallic iron deposition at the negative side of the battery controls the storage capacity. This adds complexity to the design of a porous structure of 3D-electrodes to achieve a desired high storage capacity. In addition, there is a need to control parasitic hydrogen evolution reaction which accompanies the metal deposition process, increases the pH, lowers the energy efficiency, and limits the durability. To achieve sustainable operation of IRFBs, electrolyte pH, which affects the solubility of reactants and the rate of parasitic reactions, needs to be dynamically readjusted. In the present study we explore the impact of complexing agents on maintaining solubility of the reactants and find the optimal electrolyte conditions and battery operating regime, which are specific for IRFBs with additives, and demonstrate the robust operation.Keywords: flow battery, iron-based redox flow battery, IRFB, energy storage, electrochemistry
Procedia PDF Downloads 783649 Effect of Self-Lubricating Carbon Materials on the Tribological Performance of Ultra-High Molecular Weight Polyethylene
Authors: Nayeli Camacho, Fernanda Lara-Perez, Carolina Ortega-Portilla, Diego G. Espinosa-Arbelaez, Juan M. Alvarado-Orozco, Guillermo C. Mondragon-Rodriguez
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Ultra-high molecular weight polyethylene (UHMWPE) has been the gold standard material for total knee replacements for almost five decades. Wear damage to UHMWPE articulating surface is inevitable due to the natural sliding and rolling movements of the knee. This generates a considerable amount of wear debris, which results in mechanical instability of the joint, reduces joint mobility, increases pain with detrimental biologic responses, and causes component loosening. The presence of wear particles has been closely related to adverse reactions in the knee joint surrounding tissue, especially for particles in the range of 0.3 to 2 μm. Carbon-based materials possess excellent mechanical properties and have shown great promise in tribological applications. In this study, diamond-like carbon coatings (DLC) and carbon nanotubes (CNTs) were used to decrease the wear rate of ultra-high molecular weight polyethylene. A titanium doped DLC (Ti-DLC) was deposited by magnetron sputtering on stainless steel precision spheres while CNTs were used as a second phase reinforcement in UHMWPE at a concentration of 1.25 wt.%. A comparative tribological analysis of the wear of UHMWPE and UHMWPE-CNTs with a stainless steel counterpart with and without Ti-DLC coating is presented. The experimental wear testing was performed on a pin-on-disc tribometer under dry conditions, using a reciprocating movement with a load of 1 N at a frequency of 2 Hz for 100,000 and 200,000 cycles. The wear tracks were analyzed with high-resolution scanning electron microscopy to determine wear modes and observe the size and shape of the wear debris. Furthermore, profilometry was used to study the depth of the wear tracks and to map the wear of the articulating surface. The wear tracks at 100,000 and 200,000 cycles on all samples were relatively shallow, and they were in the range of average roughness. It was observed that the Ti-DLC coating decreases the mass loss in the UHMWPE and the depth of the wear track. The combination of both carbon-based materials decreased the material loss compared to the system of stainless steel and UHMWPE. Burnishing of the surface was the predominant wear mode observed with all the systems, more subtle for the systems with Ti-DLC coatings. Meanwhile, in the system composed of stainless steel-UHMWPE, the intrinsic surface roughness of the material was completely replaced by the wear tracks.Keywords: CNT reinforcement, self-lubricating materials, Ti-DLC, UHMWPE tribological performance
Procedia PDF Downloads 1103648 Building Cardiovascular Fitness through Plyometric Training
Authors: Theresa N. Uzor
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The word cardiovascular fitness is a topic of much interest to people of Nigeria, especially during this time, some heart diseases run in families. Cardiovascular fitness is the ability of the heart and lungs to supply-rich blood to the working muscle tissues. This type of fitness is a health-related component of physical fitness that is brought about by sustained physical activity such as plyometric training. Plyometric is a form of advanced fitness training that uses fast muscular contractions to improve power and speed in the sports performance by coaches and athletes. Plyometric training involves a rapid stretching of muscle (eccentric phase) immediately followed by a concentric or shortening action of the same muscle and connective tissue. However, the most basic example of true plyometric training is running and can be safe for a wide variety of populations. This paper focused on building cardiovascular health through Plyometric Training. The centre focus of the article is cardiovascular fitness and plyometric training with factors of cardiovascular fitness. Plyometric training at any age provides multiple benefits even beyond weight control and weight loss, decrease the risk of cardiovascular diseases, stroke, high blood pressure, diabetes, and other diseases, among other benefits of plyometric training to cardiovascular fitness. Participation in plyometric training will increase metabolism of an individual, thereby burning more calories even when at rest and reduces weight is also among the benefits of plyometric training. Some guidelines were recommended for planning plyometric training programme to minimise the chance of injury. With plyometric training in Nigeria, fortune can change for good, especially now that there has been an increase in cardiovascular diseases within the society for great savings would be saved.Keywords: aerobic, cardiovascular, concentric, stretch-shortening cycle, plyometric
Procedia PDF Downloads 1393647 A Case Study of Psycho-Social Status of Rohingya Women Refugees Settled in Delhi
Authors: Fizza Saghir
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Rohingyas are an ethnic minority of predominantly Buddhist-Myanmar. Living in ghettos in Rakhine, one of the poorest states of Myanmar, for decades, they have been marginalized, discriminated, deprived of the basic amenities and have faced ghastly violations of their rights- politically, socially, economically and culturally. In 2012, in violence that, erupted between ethnic Rakhine Buddhists and Rohingya Muslims, hundreds of Rohingyas were slayed and many more displaced. The state does not recognize them as ‘citizens’ and the military and police have constantly persecuted and pushed them to either migrate to other countries like India, Bangladesh or else die of deprivation. Amidst the deadly violence, Rohingya women are the most vulnerable. Many of them have faced sexual abuse and gender-based violence. Minimalistic to insignificant studies have been done on the plight of Rohingya women refugees in context of India. Thus, this paper focuses on psycho-social status of Rohingya women refugees settled in Delhi, India. The research study used both quantitative and qualitative methods. It was explorative in nature and used non-probability sampling, purposive sampling, in particular. A sample size of 30 Rohingya women refugees was interviewed out of the universe of 45 Rohingya refugee families living in Kalindi Kunj Refugee Camp of Delhi. Case studies were developed. The paper explores the psychological and social status of the respondents along with a deep understanding of their issues and concerns. Moreover, it assesses the impact of violence and migration on respondents. It was found that Rohingya women refugees are deeply and severely affected by a violent past, an insecure present and an uncertain future. Major problems they face in Delhi, India are finding employment, lack of identity cards to avail government services, language barrier, lack of health and education facilities. All they desire is peace and shelter in India. Besides, recommendations and suggestions have been given to various stakeholders of the forced mass migration of Rohingya refugees which includes, Government of Myanmar, Government of India, other bordering nations of Myanmar, international NGOs and media and the Rohingya community, itself. Only an immediate, peaceful and continuous dialogue process can help resolve the issue of exodus of Rohingyas. Countries, including India, must come together to help the Rohingyas who are in need of urgent humanitarian aid and assistance.Keywords: dialogue process, ethnic minority, forced mass migration, impact of violence and migration, psycho-social status, Rohingya women refugees, sexual abuse
Procedia PDF Downloads 1773646 Green Synthesis of Silver and Silver-Gold Alloy Nanoparticle Using Cyanobacteria as Bioreagent
Authors: Piya Roychoudhury, Ruma Pal
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Cyanobacteria, commonly known as blue green algae were found to be an effective bioreagent for nanoparticle synthesis. Nowadays silver nanoparticles (AgNPs) are very popular due to their antimicrobial and anti-proliferative activity. To exploit these characters in different biotechnological fields, it is very essential to synthesize more stable, non-toxic nano-silver. For this reason silver-gold alloy (Ag-AuNPs) nanoparticles are of great interest as they are more stable, harder and more effective than single metal nanoparticles. In the present communication we described a simple technique for rapid synthesis of biocompatible AgNP and Ag-AuNP employing cyanobacteria, Leptolyngbya and Lyngbya respectively. For synthesis of AgNP the biomass of Leptolyngbya valderiana (200 mg Fresh weight) was exposed to 9 mM AgNO3 solution (pH 4). For synthesis of Ag-AuNP Lyngbya majuscula (200 mg Fresh weight) was exposed to equimolar solution of hydrogen tetra-auro chlorate and silver nitrate (1mM, pH 4). After 72 hrs of exposure thallus of Leptolyngyba turned brown in color and filaments of Lyngbya turned pink in color that indicated synthesis of nanoparticles. The produced particles were extracted from the cyanobacterial biomass using nano-capping agent, sodium citrate. Firstly, extracted brown and pink suspensions were taken for Energy Dispersive X-ray (EDAX) analysis to confirm the presence of silver in brown suspension and presence of both gold and silver in pink suspension. Extracted nanoparticles showed a distinct single plasmon band (AgNP at 411 nm; Ag-Au NP at 481 nm) in Uv-vis spectroscopy. It was revealed from Transmission electron microscopy (TEM) that all the synthesized particles were spherical in nature with a size range of ~2-25 nm. In X-ray powder diffraction (XRD) analysis four intense peaks appeared at 38.2°, 44.5°, 64.8°and 77.8° which confirmed the crystallographic nature of synthesized particles. Presence of different functional groups viz. N-H, C=C, C–O, C=O on the surface of nanoparticles were recorded by Fourier transform infrared spectroscopy (FTIR). Scanning Electron microscopy (SEM) images showed the surface topography of metal treated filaments of cyanobacteria. The stability of the particles was observed by Zeta potential study. Antibiotic property of synthesized particles was tested by Agar well diffusion method against gram negative bacteria Pseudomonas aeruginosa. Overall, this green-technique requires low energy, less manufacturing cost and produces rapidly eco-friendly metal nanoparticles.Keywords: cyanobacteria, silver nanoparticles, silver-gold alloy nanoparticles, spectroscopy
Procedia PDF Downloads 3233645 Solid Waste Landfilling Practices, Related Problems and Sustainable Solutions in Turkey
Authors: Nükhet Konuk, N. Gamze Turan, Yüksel Ardalı
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Solid waste management is the most environmental problem in Turkey as a result of the rapid increase in solid waste generation caused by the rapid population growth, urbanization, rapid industrialization and economic development. The large quantity of waste generated necessitates system of collection, transportation and disposal. The landfill method for the ultimate disposal of solid waste continues to be widely accepted and used due to its economic advantages. In Turkey, most of the disposal sites open dump areas. Open dump sites may result in serious urban, sanitary and environmental problems such as an unpleasant odor and the risk of explosion as well as groundwater contamination because of leachate percolation. Unsuitable management practices also result in the loss of resources and energy, which could be recycled and produced from a large part of the solid waste. Therefore, over the past few decades, particular attention has been drawn to the sustainable solid waste management as a response to the increase in environmental problems related to the disposal of waste. The objective of this paper is to assess the situation of landfilling practices in Turkey as a developing country and to identify any gaps in the system as currently applied. The results show that approximately 25 million tons of MSW are generated annually in Turkey. The percentage of MSW disposed to sanitary landfill is only 45% whereas more than 50% of MSW is disposed without any control.Keywords: developing countries, open dumping, solid waste management, sustainable landfilling, sustainable solid waste management
Procedia PDF Downloads 3013644 Management of Fungal Diseases of Onion (Allium cepa L.) by Using Plant Extracts
Authors: Shobha U. Jadhav, R. S. Saler
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Onion is most Important Vegetable crop grown throughout the world. Onion suffers from pest and fungal diseases but the fungicides cause pollution and disturb microbial balance of soil. Under integrated fungal disease management programme cost effective and eco- friendly component like plant extract are used to control plant pathogens. Alternaria porri, Fusarium oxysporium, Stemphylium vesicarium are soil borne pathogens of onion. Effect of three different plant extract (Datura metel, Pongamia pinnata, Ipomoea palmata) at five different concentration Viz, 10,25,50,75 and 100 percentage on these pathogens was studied by food poisoning techniquie. Detura metal gave 94.73% growth of Alternaria porri at 10% extract concentraton and 26.31% growth in 100% extract concentration. As compared to Fusarium oxysporium, and Stemphylium vesicarium, Alternaria porri give good inhibitory response. In Pongamia pinnata L. at 10% extract concentration 84.21% growth and at 100% extract concentration 36.84% growth of Stemphylium vesicarium was observed. Stemphylium vesicarium give good in inhibitory response as compared to Alternaria porri and Fusarium oxysporium. Ipomoea palmata in 10% extract concentration 92% growth and in 100% extract concentration 40% growth of Fusarium oxysporium was recorded. Fusarium oxysporium give good inhibitory response as compared to Alternaria porri and, Stemphylium vesicarium.Keywords: pathogen, onion, plant extract, Allium cepa L.
Procedia PDF Downloads 4663643 A Neural Network Approach for an Automatic Detection and Localization of an Open Phase Circuit of a Five-Phase Induction Machine Used in a Drivetrain of an Electric Vehicle
Authors: Saad Chahba, Rabia Sehab, Ahmad Akrad, Cristina Morel
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Nowadays, the electric machines used in urban electric vehicles are, in most cases, three-phase electric machines with or without a magnet in the rotor. Permanent Magnet Synchronous Machine (PMSM) and Induction Machine (IM) are the main components of drive trains of electric and hybrid vehicles. These machines have very good performance in healthy operation mode, but they are not redundant to ensure safety in faulty operation mode. Faced with the continued growth in the demand for electric vehicles in the automotive market, improving the reliability of electric vehicles is necessary over the lifecycle of the electric vehicle. Multiphase electric machines respond well to this constraint because, on the one hand, they have better robustness in the event of a breakdown (opening of a phase, opening of an arm of the power stage, intern-turn short circuit) and, on the other hand, better power density. In this work, a diagnosis approach using a neural network for an open circuit fault or more of a five-phase induction machine is developed. Validation on the simulator of the vehicle drivetrain, at reduced power, is carried out, creating one and more open circuit stator phases showing the efficiency and the reliability of the new approach to detect and to locate on-line one or more open phases of a five-induction machine.Keywords: electric vehicle drivetrain, multiphase drives, induction machine, control, open circuit (OC) fault diagnosis, artificial neural network
Procedia PDF Downloads 2093642 Numerical Simulation of Lifeboat Launching Using Overset Meshing
Authors: Alok Khaware, Vinay Kumar Gupta, Jean Noel Pederzani
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Lifeboat launching from marine vessel or offshore platform is one of the important areas of research in offshore applications. With the advancement of computational fluid dynamic simulation (CFD) technology to solve fluid induced motions coupled with Six Degree of Freedom (6DOF), rigid body dynamics solver, it is now possible to predict the motion of the lifeboat precisely in different challenging conditions. Traditionally dynamic remeshing approach is used to solve this kind of problems, but remeshing approach has some bottlenecks to control good quality mesh in transient moving mesh cases. In the present study, an overset method with higher-order interpolation is used to simulate a lifeboat launched from an offshore platform into calm water, and volume of fluid (VOF) method is used to track free surface. Overset mesh consists of a set of overlapping component meshes, which allows complex geometries to be meshed with lesser effort. Good quality mesh with local refinement is generated at the beginning of the simulation and stay unchanged throughout the simulation. Overset mesh accuracy depends on the precise interpolation technique; the present study includes a robust and accurate least square interpolation method and results obtained with overset mesh shows good agreement with experiment.Keywords: computational fluid dynamics, free surface flow, lifeboat launching, overset mesh, volume of fluid
Procedia PDF Downloads 2773641 Improving the Quality of Staff Performance with a Talent-Driven Approach: Case Study of SAIPA Automotive Manufacturing Company in Iran
Authors: Abdolmajid Mosleh, Afzal Ghasimi
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The purpose of this research is to investigate and identify effective factors that can improve the quality of personal performance in industrial companies. In the present study, it was assumed that the hidden variables of talent management could be explained by an important part of the variance in improving the quality of employee performance. This research is targeted in terms of applied research. The statistical population of the research is SAIPA automobile company with a number (N=10291); the sample of 380 people was selected based on the Cochran formula in a random sampling method among employed people. The measurement tool in this research was a questionnaire of 33 items with a control questionnaire that included two talent management departments (talent identification and talent exploitation) and improvements in staff performance (enhancement of technical and specialized capabilities, managerial capability, organizational interaction, and communication). The reliability of the internal consistency method was confirmed by the Cronbach's alpha coefficient and the two half-ways. In order to determine the validity of the questionnaire structure, confirmatory factor analysis was used. Based on the results of the data analysis, the effect of talent management on improving the quality of staff performance was confirmed. Based on the results of inferential statistics and structural equations of the proposed model, it had high fitness.Keywords: employee performance, talent management, performance improvement, SAIPA automobile manufacturing company
Procedia PDF Downloads 903640 Life Table and Functional Response of Scolothrips takahashii (Thysanoptera: Thripidae) on Tetranychus urticae (Acari:Tetranychidae)
Authors: Kuang-Chi Pan, Shu-Jen Tuan
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Scolothrips takahashii Priesner (Thysanoptera: Thripidae) is a common predatory thrips which feeds on spider mites; it is considered an important natural enemy and a potential biological control agent against spider mites. In order to evaluate the efficacy of S. takahashii against tetranychid mites, life table and functional response study were conducted at 25±1°C, with Tetranychus urticae Priesner as prey. The intrinsic rate of increase (r), finite rate of increase (λ), net reproduction rate (R₀), mean generation time (T) were 0.1674 d⁻¹, 1.1822d⁻¹, 62.26 offspring/individual, and 24.68d. The net consumption rate (C₀) was 846.15, mean daily consumption rate was 51.92 eggs for females and 19.28 eggs for males. S. takahashii exhibited type III functional response when offered T. urticae deutonymphs. Based on the random predator equation, the estimated maximum attack rate (a) and handling time (Th) were 0.1376h⁻¹ and 0.7883h. In addition, a life table experiment was conducted to evaluate the offspring sex allocation and population dynamic of Tetranychus ludeni Zacher under group-rearing conditions with different sex ratios. All bisexual groups produced offspring with similar sex allocation patterns, which started with the majority of females, then transited during the middle of the oviposition period and turned male-biased at the end of the oviposition period.Keywords: Scolothrips takahashii, Tetranychus urticae, Tetranychus ludeni, two-sex life table, functional response, sex allocation
Procedia PDF Downloads 903639 Numerical Study of Microdrops Manipulation by MicroFluidic Oscillator
Authors: Tawfiq Chekifi, Brahim Dennai, Rachid Khelfaoui
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Over the last few decades, modeling immiscible fluids such as oil and water have been a classical research topic. Droplet-based microfluidics presents a unique platform for mixing, reaction, separation, dispersion of drops and numerous other functions. for this purpose Several devices were studied, as well as microfluidic oscillator. The latter was obtained from wall attachment microfluidic amplifiers using a feedback loop from the outputs to the control inputs, nevertheless this device haven’t well used for microdrops applications. In this paper, we suggest a numerical CFD study of a microfluidic oscillator with two different lengths of feedback loop. In order to produce simultaneous microdrops of gasoil on water, a typical geometry that includes double T-junction is connected to the fluidic oscillator, The generation of microdrops is computed by volume-of-fluid method (VOF). Flow oscillations of microdrops were triggered by the Coanda effect of jet flow. The aim of work is to obtain a high oscillation frequency in output of this passive device, the influence of hydrodynamics and physics parameters on the microdrops frequency in the output of our microsystem is also analyzed, The computational results show that, the length of feedback loop, applied pressure on T-junction and interfacial tension have a significant effect on the dispersion of microdrops and its oscillation frequency. Across the range of low Reynold number, the microdrops generation and its dynamics have been accurately controlled by adjusting applying pressure ratio of two phases.Keywords: fluidic oscillator, microdrops manipulation, volume of fluid method, microfluidic oscillator
Procedia PDF Downloads 4893638 A Preliminary Study of Local Customers' Perception towards the Image of the Spa and Their Intention to Visit
Authors: Felsy J. Sandi
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There is a potential of growth in the spa industry due to the influx of domestic and international tourist coming to Sabah, Malaysia. It is a good opportunity to venture into this industry for the country’s economic future growth, and therefore, it is essential for this area to be researched. Being one of the fastest growing industries in the world, has led to enormous challenges, which need to be addressed. Malaysia is also riding with this phenomenon. The President of the Malaysian Association of Wellness and Spa stated that the misconception about the Spa industry’s image, especially amongst the elderly is the biggest challenge faced by the industry, as they perceived the spa industry is equivalent to a prostitution center. Therefore, the objective of this study is to explore the issue by analyzing whether image can be added in the theory of planned behavior to better understand the consumer’s intention to visit, in the spa context. The Theory of Planned Behavior by Ajzen, a theory or model in predicting intention, has three constructs; such as Attitude as the first construct, the second construct is Subjective Norm and the third construct is Perceived Behavioral Control. Qualitative research is used as this is an exploratory research. The site of study will be at Jari Jari Spa, located in Kota Kinabalu, the only spa in Sabah that was awarded as the Center of Excellence (CoE) by the Ministry of Tourism and Culture in Malaysia. The findings propose to provide useful information to the relevant stakeholders on ways to approach local customers to convince them to visit the spa and for spa marketers to help them develop and design effective marketing strategies. Future investigation should consider more on the perception and loyalty of the local customers.Keywords: consumer's perception, image, local customer, spa, visit intention
Procedia PDF Downloads 2703637 Gas Network Noncooperative Game
Authors: Teresa Azevedo PerdicoúLis, Paulo Lopes Dos Santos
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The conceptualisation of the problem of network optimisation as a noncooperative game sets up a holistic interactive approach that brings together different network features (e.g., com-pressor stations, sources, and pipelines, in the gas context) where the optimisation objectives are different, and a single optimisation procedure becomes possible without having to feed results from diverse software packages into each other. A mathematical model of this type, where independent entities take action, offers the ideal modularity and subsequent problem decomposition in view to design a decentralised algorithm to optimise the operation and management of the network. In a game framework, compressor stations and sources are under-stood as players which communicate through network connectivity constraints–the pipeline model. That is, in a scheme similar to tatonnementˆ, the players appoint their best settings and then interact to check for network feasibility. The devolved degree of network unfeasibility informs the players about the ’quality’ of their settings, and this two-phase iterative scheme is repeated until a global optimum is obtained. Due to network transients, its optimisation needs to be assessed at different points of the control interval. For this reason, the proposed approach to optimisation has two stages: (i) the first stage computes along the period of optimisation in order to fulfil the requirement just mentioned; (ii) the second stage is initialised with the solution found by the problem computed at the first stage, and computes in the end of the period of optimisation to rectify the solution found at the first stage. The liability of the proposed scheme is proven correct on an abstract prototype and three example networks.Keywords: connectivity matrix, gas network optimisation, large-scale, noncooperative game, system decomposition
Procedia PDF Downloads 1523636 Perceived Effect of Physical Exercise on Healthy Well-Being of Pregnant Women in Imo State
Authors: Roseline Chizoba Onuoha, Rose Ngozi Uzoka
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This study aimed at investigating perceived effect of physical exercise on healthy well-being of pregnant mothers in Imo state. The study was guided by three research questions and three null hypotheses tested at 0.05 level of significance. The study was a quasi-experimental non-equivalent control group design involving pre and post tests. A sample of 92 pregnant women drawn from a total population of 922 registered pregnant women in ten randomly selected health centers in Imo State through multistage sampling technique was used. A 41 item structured instrument titled Physical Exercise Pregnancy Test (PEPT) was used for the study. The PEPT was validated by three experts from measurement and evaluation, educational psychology and health education. Crombach Alpha method was used to determine the reliability of Physical Exercise Pregnancy Test (PEPT) and reliability index of 0.82 was obtained. Mean and standard deviation were used to answer the research questions; while Analysis of Covariance (ANCOVA) was used in analyzing the hypotheses. Findings of the study revealed that physical exercise affects physical, social and emotional wellbeing scores of pregnant women. The study also indicated that intervention using physical exercise significantly enhanced healthy well-being scores of pregnant mothers who were exposed to physical exercise than those who received conventional health talks; Location has no significant interaction effect on the mean well-being scores of pregnant women via PEPT. Among recommendations made were that pregnant women should participate in physical exercise.Keywords: educational psychology, Imo state, Physical exercise, pregnant women
Procedia PDF Downloads 1383635 Analysis of Two-Phase Flow Instabilities in Conventional Channel of Nuclear Power Reactor
Authors: M. Abdur Rashid Sarkar, Riffat Mahmud
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Boiling heat transfer plays a crucial role in cooling nuclear reactor for safe electricity generation. A two phase flow is susceptible to thermal-hydrodynamic instabilities, which may cause flow oscillations of constant amplitude or diverging amplitude. These oscillations may induce boiling crisis, disturb control systems, or cause mechanical damage. Based on their mechanisms, various types of instabilities can be classified for a nuclear reactor. From a practical engineering point of view one of the major design difficulties in dealing with multiphase flow is that the mass, momentum, and energy transfer rates and processes may be quite sensitive to the geometric configuration of the heat transfer surface. Moreover, the flow within each phase or component will clearly depend on that geometric configuration. The complexity of this two-way coupling presents a major challenge in the study of multiphase flows and there is much that remains to be done. Yet, the parametric effects on flow instability such as the effect of aspect ratio, pressure drop, channel length, its orientation inlet subcooling and surface roughness etc. have been analyzed. Another frequently occurring instability, known as the Kelvin–Helmholtz instability has been briefly reviewed. Various analytical techniques for predicting parametric effect on the instability are analyzed in terms of their applicability and accuracy.Keywords: two phase flows, boiling crisis, thermal-hydrodynamic instabilities, water cooled nuclear reactors, kelvin–helmholtz instability
Procedia PDF Downloads 3973634 Research on the Optimization of Satellite Mission Scheduling
Authors: Pin-Ling Yin, Dung-Ying Lin
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Satellites play an important role in our daily lives, from monitoring the Earth's environment and providing real-time disaster imagery to predicting extreme weather events. As technology advances and demands increase, the tasks undertaken by satellites have become increasingly complex, with more stringent resource management requirements. A common challenge in satellite mission scheduling is the limited availability of resources, including onboard memory, ground station accessibility, and satellite power. In this context, efficiently scheduling and managing the increasingly complex satellite missions under constrained resources has become a critical issue that needs to be addressed. The core of Satellite Onboard Activity Planning (SOAP) lies in optimizing the scheduling of the received tasks, arranging them on a timeline to form an executable onboard mission plan. This study aims to develop an optimization model that considers the various constraints involved in satellite mission scheduling, such as the non-overlapping execution periods for certain types of tasks, the requirement that tasks must fall within the contact range of specified types of ground stations during their execution, onboard memory capacity limits, and the collaborative constraints between different types of tasks. Specifically, this research constructs a mixed-integer programming mathematical model and solves it with a commercial optimization package. Simultaneously, as the problem size increases, the problem becomes more difficult to solve. Therefore, in this study, a heuristic algorithm has been developed to address the challenges of using commercial optimization package as the scale increases. The goal is to effectively plan satellite missions, maximizing the total number of executable tasks while considering task priorities and ensuring that tasks can be completed as early as possible without violating feasibility constraints. To verify the feasibility and effectiveness of the algorithm, test instances of various sizes were generated, and the results were validated through feedback from on-site users and compared against solutions obtained from a commercial optimization package. Numerical results show that the algorithm performs well under various scenarios, consistently meeting user requirements. The satellite mission scheduling algorithm proposed in this study can be flexibly extended to different types of satellite mission demands, achieving optimal resource allocation and enhancing the efficiency and effectiveness of satellite mission execution.Keywords: mixed-integer programming, meta-heuristics, optimization, resource management, satellite mission scheduling
Procedia PDF Downloads 253633 Dopamine and Female Sexual Function: A Clinical and Biochemical Study
Authors: Azza Gaber Antar Farag, Eman Abd El Fatah Badr, Wesam Ahmed Tawfik Hasssan Abdel Aal, Mustafa Elsayed Elshaib
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Background: Female Sexual Dysfunction (FSD) represents recurrent and persistent problems that distress women and/or strain their relationships with their partners. Dopamine can affect sexual function and interacts with ovarian hormones in the ventromedial area in the hypothalamus. Objective: To investigate the possible role of dopamine in FSD. Method: This prospective case-control study was carried on 100 women having FSD and 100 healthy volunteer females. They were recruited from the Al-Menoufia governorate. All included women were subjected to the questionnaire to assess their demographic and gynecological data as well as sexual function. They were investigated for serum levels of dopamine, estradiol, progesterone and DHEA hormones. Results: Dopamine serum levels were significantly lower in females having sexual dysfunction (6.68±4.14) than controls (57.97±26.26) (P>0.001). This decreased dopamine level was of a significant positive correlation with the arousal domain and significant negative correlation regarding the pain domain (r=-0.19, p=0.01). Also, estradiol serum levels were significantly lower (P>0.001), but progesterone and DHEA serum levels were significantly higher in the FSD group than controls (P>0.001). There was a significant negative correlation between dopamine and DHEA serum levels (r= -0.45, p <0.001). Conclusions: Decreased dopamine serum levels may have an active role in the pathophysiology of FSD, impacting mainly arousal and pain domains, and its targeting should be considered during FSD management.Keywords: dopamine, estradiol, progesterone, DHEA, females sexual dysfunction
Procedia PDF Downloads 1673632 Effect of Oral Immonoglobulin (IgY) Ingestion on Post Exercise Muscle Soreness and Muscle Damage Markers in Females
Authors: Bert H. Jacobson, Taylor Monaghan, John Sellers
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Intense resistance-type activity generally elicits delayed onset muscle soreness (DOMS) in individuals unaccustomed to such action. DOMS is a combination of contractile tissue microtrauma, osmotic pressure changes, alteration calcium regulation, and inflammation. Elevated muscle-specific enzyme creatine kinase (CK) is a marker of striated muscle damage. Avian immunoglobulin (IgY) mediates inflammation and may thereby reduce post-exercise DOMS. Purpose: The aim of this study was to compare the effect of oral IgY and placebo (Pl) on CK, serum relevels, and perceived pain following induced DOMS. Methods: Healthy college-aged females (N=16) were randomly divided into an experimental group (IgY) and a control group (PL). CK serum levels were recorded followed by 14 days of supplementation of either IgY or Pl at the following doses: days 1-2 =4.5 g, days 3-5 =9.0 g, and days 6-14 =13.5 g. Following the 14 d, lower limb DOMS was induced using two methods of resistance training. After 48 hours, subjects reported for a second blood draw. Results: One-way ANOVA resulted in the IgY group posting significantly less (p < 0.05) serum CK than the PL group. Furthermore, the IgY group experienced significantly less post-test perceived soreness than the Pl group. Conclusion: IgY supplementation lessens muscle CK levels and perceived muscle soreness following exercise, possibly due to an anti-inflammatory effect. It was suggested that IgY may serve as a buffer for DOMS thereby allowing the participant to continue vigorous exercise without discomfort.Keywords: muscle, soreness, damage, serum
Procedia PDF Downloads 1973631 A Transnational Feminist Analysis of the Experiences of Return Migrant Women to Kosova
Authors: Kaltrina Kusari
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Displaced populations have received increasing attention, yet the experiences of return migrants remain largely hidden within social sciences. Existing research, albeit limited, suggests that policies which impact return migrants, especially those forced to return to their home countries, do not reflect their voices. Specifically, the United Nations Hight Commissioner for Refugees has adopted repatriation as a preferred policy solution, despite research which substantiates that returning to one’s home country is neither durable nor the end of the migration cycle; as many of 80% of returnees decide to remigrate. This one-size-fits-all approach to forced displacement does not recognize the impact of intersecting identity categories on return migration, thus failing to consider how ethnicity, gender, and class, among others, shape repatriation. To address this, this qualitative study examined the repatriation experiences of return migrant women from Kosovo and the role of social workers in facilitating return. In 2015, Kosovars constituted the fourth largest group of asylum seekers in the European Union, yet 96% of them were rejected. Additionally, since 1999 Kosovo has ranked among the top 10 countries of origin for return migrants. Considering that return migration trends are impacted by global power dynamics, this study relied on a postcolonial and transnational feminist framework to contextualize the mobility of displaced peoples in terms of globalization and conceptualize migration as a gendered process. Postcolonial and feminist theories suggest that power is partly operationalized through language, thus, Critical Discourse Analysis was used as a research methodology. CDA is concerned with examining how power, language, and discourses shape social processes and relationships of dominance. Data collection included interviews with 15 return migrant women (eight ethnic minorities and seven Albanian) and 18 service providers in Kosovo. The main findings illustrate that both returnee women and service providers rely on discourses which 1) challenge the voluntariness and sustainability of repatriation; 2) construct Kosovo as inferior to EU countries; and 3) highlight the impact of patriarchy and ethnic racism on return migration. A postcolonial transnational feminist analysis demonstrates that despite Kosovars’ challenges with repatriation, European Union countries use their power to impose repatriation as a preferred solution for Kosovo’s government. These findings add to the body of existing repatriation literature and provide important implications for how return migration might be carried out, not only in Kosovo but other countries as well.Keywords: migration, gender, repatriation, transnational feminism
Procedia PDF Downloads 823630 Screening of Thyroid Stimulating Hormone Using Paper-Based Lateral Flow Device
Authors: Pattarachaya Preechakasedkit, Kota Osada, Koji Suzuki, Daniel Citterio, Orawon Chailapakul
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A paper-based lateral flow device for screening thyroid stimulating hormone (TSH) is reported. A sandwich immunoassay was performed using two mouse monoclonal TSH antibodies (anti-hTSH 5403 and 5404) as immobilized and labeled antibodies for capturing TSH samples. Test (anti-hTSH 5403) and control (goat anti-Mouse IgG) lines were fabricated on nitrocellulose membrane (NCM) using ballpoint pen printed with a speed of 3 cm/s and thickness setting of 1. The novel gold nanoparticles europium complex (AuNPs@Eu) was used as fluorescence label compared to conventional AuNPs label. The results obtained with this device can be visually assessed by the naked eyes and under UV hand lamps, and quantitative analysis can be performed using the ImageJ program. The limit of detection (LOD) under UV hand lamps (0.1 µIU/mL) provided 50-fold greater sensitivity than AuNPs (5 µIU/mL), which is suitable for both hypothyroidism and hyperthyroidism screening within 30 min. A linear relationship between the red intensity and the logarithmic concentrations of TSH was observed with a good correlation (R²=0.992). Furthermore, the device can be effectively applied for screening TSH in the spiked human serum with recovery range of 96.80-104.45% and RSD of 2.18-3.63%. Therefore, the developed device is an alternative method for TSH screening which provides a lot of advantages including low cost, short time analysis, ease of use, disposability, portability, and on-site measurement.Keywords: thyroid stimulating hormone, paper-based lateral flow, hypothyroidism, hyperthyroidism
Procedia PDF Downloads 3643629 The Role of Demographics and Service Quality in the Adoption and Diffusion of E-Government Services: A Study in India
Authors: Sayantan Khanra, Rojers P. Joseph
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Background and Significance: This study is aimed at analyzing the role of demographic and service quality variables in the adoption and diffusion of e-government services among the users in India. The study proposes to examine the users' perception about e-Government services and investigate the key variables that are most salient to the Indian populace. Description of the Basic Methodologies: The methodology to be adopted in this study is Hierarchical Regression Analysis, which will help in exploring the impact of the demographic variables and the quality dimensions on the willingness to use e-government services in two steps. First, the impact of demographic variables on the willingness to use e-government services is to be examined. In the second step, quality dimensions would be used as inputs to the model for explaining variance in excess of prior contribution by the demographic variables. Present Status: Our study is in the data collection stage in collaboration with a highly reliable, authentic and adequate source of user data. Assuming that the population of the study comprises all the Internet users in India, a massive sample size of more than 10,000 random respondents is being approached. Data is being collected using an online survey questionnaire. A pilot survey has already been carried out to refine the questionnaire with inputs from an expert in management information systems and a small group of users of e-government services in India. The first three questions in the survey pertain to the Internet usage pattern of a respondent and probe whether the person has used e-government services. If the respondent confirms that he/she has used e-government services, then an aggregate of 15 indicators are used to measure the quality dimensions under consideration and the willingness of the respondent to use e-government services, on a five-point Likert scale. If the respondent reports that he/she has not used e-government services, then a few optional questions are asked to understand the reason(s) behind the same. Last four questions in the survey are dedicated to collect data related to the demographic variables. An indication of the Major Findings: Based on the extensive literature review carried out to develop several propositions; a research model is prescribed to start with. A major outcome expected at the completion of the study is the development of a research model that would help to understand the relationship involving the demographic variables and service quality dimensions, and the willingness to adopt e-government services, particularly in an emerging economy like India. Concluding Statement: Governments of emerging economies and other relevant agencies can use the findings from the study in designing, updating, and promoting e-government services to enhance public participation, which in turn, would help to improve efficiency, convenience, engagement, and transparency in implementing these services.Keywords: adoption and diffusion of e-government services, demographic variables, hierarchical regression analysis, service quality dimensions
Procedia PDF Downloads 2673628 Land Use, Land Cover Changes and Woody Vegetation Status of Tsimur Saint Gebriel Monastery, in Tigray Region, Northern Ethiopia
Authors: Abraha Hatsey, Nesibu Yahya, Abeje Eshete
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Ethiopian Orthodox Tewahido Church has a long tradition of conserving the Church vegetation and is an area treated as a refugee camp for many endangered indigenous tree species in Northern Ethiopia. Though around 36,000 churches exist in Ethiopia, only a few churches have been studied so far. Thus, this study assessed the land use land cover change of 3km buffer (1986-2018) and the woody species diversity and regeneration status of Tsimur St. Gebriel monastery in Tigray region, Northern Ethiopia. For vegetation study, systematic sampling was used with 100m spacing between plots and between transects. Plot size was 20m*20m for the main plot and 2 subplots (5m*5m each) for the regeneration study. Tree height, diameter at breast height(DBH) and crown area were measured in the main plot for all trees with DBH ≥ 5cm. In the subplots, all seedlings and saplings were counted with DBH < 5cm. The data was analyzed on excel and Pass biodiversity software for diversity and evenness analysis. The major land cover classes identified include bare land, farmland, forest, shrubland and wetland. The extents of forest and shrubland were declined considerably due to bare land and agricultural land expansions within the 3km buffer, indicating an increasing pressure on the church forest. Regarding the vegetation status, A total of 19 species belonging to 13 families were recorded in the monastery. The diversity (H’) and evenness recorded were 2.4 and 0.5, respectively. The tree density (DBH ≥ 5cm) was 336/ha and a crown cover of 65%. Olea europaea was the dominant (6.4m2/ha out of 10.5m2 total basal area) and a frequent species (100%) with good regeneration in the monastery. The rest of the species are less frequent and are mostly confined to water sources with good site conditions. Juniperus procera (overharvested) and the other indigenous species were with few trees left and with no/very poor regeneration status. The species having poor density, frequency and regeneration (Junperus procera, Nuxia congesta Fersen and Jasminium abyssinica) need prior conservation and enrichment planting. The indigenous species could also serve as a potential seed source for the reproduction and restoration of nearby degraded landscapes. The buffer study also demonstrated expansion of agriculture and bare land, which could be a threat to the forest of the isolated monastery. Hence, restoring the buffer zone is the only guarantee for the healthy existence of the church forest.Keywords: church forests, regeneration, land use change, vegetation status
Procedia PDF Downloads 2053627 Quantification of Enzymatic Activities of Proteins, Peroxidase and Phenylalanine Ammonia Lyase, in Growing Phaseolus vulgaris L, with Application Bacterial Consortium to Control Fusarium and Rhizoctonia
Authors: Arredondo Valdés Roberto, Hernández Castillo Francisco Daniel, Laredo Alcalá Elan Iñaky, Gonzalez Gallegos Esmeralda, Castro Del Angel Epifanio
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The common bean or Phaseolus vulgaris L. is the most important food legume for direct consumption in the world. Fusarium dry rot in the major fungus disease affects Phaseolus vulgaris L, after planting. In another hand, Rhizoctonia can be found on all underground parts of the plant and various times during the growing season. In recent years, the world has conducted studies about the use of natural products as substitutes for herbicides and pesticides, because of possible ecological and economic benefits. Plants respond to fungal invasion by activating defense responses associated with accumulation of several enzymes and inhibitors, which prevent pathogen infection. This study focused on the role of proteins, peroxidase (POD), phenylalanine ammonia lyase (PAL), in imparting resistance to soft rot pathogens by applied different bacterial consortium, formulated and provided by Biofertilizantes de Méxicanos industries, analyzing the enzyme activity at different times of application (6 h, 12 h and 24 h). The resistance of these treatments was correlated with high POD and PAL enzyme activity as well as increased concentrations of proteins. These findings show that PAL, POD and synthesis of proteins play a role in imparting resistance to Phaseolus vulgaris L. soft rot infection by Fusarium and Rhizoctonia.Keywords: fusarium, peroxidase, phenylalanine ammonia lyase, rhizoctonia
Procedia PDF Downloads 3523626 Family Firms and Investment–Cash Flow Sensitivity: Empirical Evidence from Canada
Authors: Imen Latrous
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Family firm is the most common form of business organization in the world. Many family businesses rely heavily on their own capital to finance their expansion. This dependence on internal funds for their investment may be deliberate to maintain the family dominant position or involuntary as family firms have limited access to external funds. Our understanding of family firm’s choice to fund their own growth using existing capital is somewhat limited. The aim of this paper is to study whether the presence of a controlling family in the company either mitigates or exacerbates external financing constraints. The impact of family ownership on investment–cash flow sensitivity is ultimately an empirical question. We use a sample of 406 Canadian firms listed in Toronto Stock exchange (TSX) over the period 2005–2014 in order to explore this relationship. We distinguish between three elements in the definition of family firms, specifically ownership, control and management, to explore the issue whether family firms are more efficient organisational form. Our research contributes to the extant literature on family ownership in several ways. First, as our understanding of family firm’s investment cash flow sensitivity is somewhat limited in recession times, we explore the effect of family firms on the relation between investment and cash flow during the recent 2007-2009 financial crisis. We also analyse this relationship difference between family firms and non family firms before and during financial crisis. Finally, our paper addresses the endogeneity problem of family ownership and investment-cash flow sensitivity.Keywords: family firms, investment–cash flow sensitivity, financial crisis, corporate governance
Procedia PDF Downloads 3253625 Periodontal Disease or Cement Disease: New Frontier in the Treatment of Periodontal Disease in Dogs
Authors: C. Gallottini, W. Di Mari, A. Amaddeo, K. Barbaro, A. Dolci, G. Dolci, L. Gallottini, G. Barraco, S. Eramo
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A group of 10 dogs (group A) with Periodontal Disease in the third stage, were subjected to regenerative therapy of periodontal tissues, by use of nano hydroxy apatite (NHA). These animals induced by general anesthesia, where treated by ultrasonic scaling, root planning, and at the end by a mucogingival flap in which it was applied NHA. The flap was closed and sutured with simple steps. Another group of 10 dogs (group B), control group, was treated only by scaling and root planning. No patient was subjected to antibiotic therapy. After three months, a check was made by inspection of the oral cavity, radiography and bone biopsy at the alveolar level. Group A showed a total restitutio ad integrum of the periodontal structures, and in group B still mild gingivitis in 70% of cases and 30% of the state remains unchanged. Numerous experimental studies both in animals and humans have documented that the grafts of porous hydroxyapatite are rapidly invaded by fibrovascular tissue which is subsequently converted into mature lamellar bone tissue by activating osteoblast. Since we acted on the removal of necrotic cementum and rehabilitating the root tissue by polishing without intervention in the ligament but only on anatomical functional interface of cement-blasts, we can connect the positive evolution of the clinical-only component of the cement that could represent this perspective, the only reason that Periodontal Disease become a Cement Disease, while all other clinical elements as nothing more than a clinical pathological accompanying.Keywords: nanoidroxiaphatite, parodontal disease, cement disease, regenerative therapy
Procedia PDF Downloads 4503624 Development of Value Added Product Based on Millets and Hemp Seed (cannabis sativa L.)
Authors: Khushi Kashyap, Pratibha Singh
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In the recent years increasing interest in vegetarian diets has been observed, a major problem in this type of diet is to provide the appropriate amount of protein .Value addition of food is current most talked topic because of increasing nutritional awareness among consumers today. An investigation was conducted to develop protein rich multi-millet hemp seed khakhra. The seeds of cannabis sativa L. have been a significant source of food for thousand of year. In recent years, hemp has not been thoroughly explored for its nutritional potential due to the mistaken belief regarding the cannabis plants. Methodology- two variations was prepared referencing standard recipe. Variation 1 was prepared using 25g ragi, 25g bajra,40g whole wheat flour with 10g hemp seed powder, variation 2(RF-25g,BF25g,WWF-35g,HS-15g). The product was subjected to sensory evolution by semi trained panel members using 9 point hedonic on 50 panelists. Result- result of the sensory evaluation revealed that the product incorporated with 15g of hemp seed were similar to control I texture, taste and overall quality and was more acceptable by the panelist and was selected as final product seed. On estimation of the nutrient content 30g of khakhra provides 107kcal of energy,12g protein,75g carbohydrate, and 9.6g of fats with shelf life of 3 months. Conclusion- khakhras can be eaten as a snack at any time of the day. hemp seed powder incorporated in it enhances its nutritive value and makes it more nutritious. It is suitable for consumption of all the age group.Keywords: cannabis sativa, hemp, protein, seed
Procedia PDF Downloads 913623 Effects of Cymbopogon citratus, Stapf (CS) or Lemon Grass Ethanol Extract on Antioxidant and Vascular Disorders Parameters in Rat
Authors: Suphaket Saenthaweesuk, Nutiya Somparn, Atcharaporn Thewmore
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The present study aims to investigate the effects of Cymbopogon citratus, Stapf (CS) or lemon grass ethanol extract on antioxidant and vascular disorders parameters in rat. The CS ethanol extract was screened for its phytochemical contents and antioxidant activity in vitro. Moreover, the extract was studied in rats to evaluate its effects in vivo. Rats were orally administered with CS at 1,000 mg/kg/day for 30 days. Phytochemical screening of CS extract indicated the presence of tannins, flavonoids and phenolic compounds. The extract contained phenolic compounds 1,400.10 ± 0.47 mg of gallic acid equivalents per gram CS extract. The free radical scavenging activity assessed by DPPH assay gave IC50 of 168.77 ± 3.32µg/mL, which is relatively lower than that of BHT with IC50 of 12.34 ± 1.14 µg/mL. In the animals, the protein expression of antioxidant enzymes, γ-glutamylcysteine ligase (γ-GCL) in liver was significantly increased. This was consistent with elevation of serum catalase (CAT) and superoxide dismutase (SOD) activities. However, Protein expression of vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule (ICAM-1) and endothelial nitric oxide synthase (eNOS) in heart and aorta were not differenced from normal control. Taken together, the present study provides evidence that CCS water extract exhibits direct antioxidant properties and can induce cytoprotective enzymes in vivo.Keywords: antioxidant, Cymbopogon citratus Stapf, VCAM-1, γ-glutamylcysteine ligase
Procedia PDF Downloads 309