Search results for: combined anaerobic-aerobic degradation
2390 Green Synthesis of Silver Nanoparticles, Their Toxicity and Biomedical Applications
Authors: Kiran Shehzadi, Yasmeen Akhtar, Mujahid Ameen, Tabinda Ijaz, Shoukat Siddique
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Nanoparticles, due to their different sizes and morphologies, are employed in various fields such as the medical field, cosmetics, pharmaceutical, textile industry as well as in paints, adhesives, and electronics. Metal nanoparticles exhibit excellent antimicrobial activity, dye degradation and can be used as anti-cancerous drug loading agents. In this study, sZilver nanoparticles (Ag-NPs) were synthesized employing doxycycline (antibiotic) as a reducing and capping agent (biological/green synthesis). Produced Ag-NPS were characterized using UV/VIS spectrophotometry, XRD, SEM, and FTIR. Surface plasmon resonance (SPR) of silver nanoparticles was observed at 411nm with 90nm size with homogenized spherical shape. These particles revealed good inhibition zones for Fungi such as Candida albicans and Candida tropicalis. In this study, toxic properties of Ag-NPs were monitored by allowing them to penetrate in the cell, causing an abrupt increase in oxidative stress, which resulted ultimately in cell death. Histopathological analysis of mice organs was performed by administering definite concentrations of silver nanoparticles orally to mice for 14 days. Toxic properties were determined, and it was revealed that the toxicity of silver nanoparticles mainly depends on the size. Silver nanoparticles of this work presented mild toxicity for different organs (liver, kidney, spleen, heart, and stomach) of mice.Keywords: metal nanoparticles, green/biological methods, toxicity, Candida albicans, Candida tropicalis
Procedia PDF Downloads 1292389 Epidemiology, Prevention and Treatment of Leishmaniasis in Afghanistan
Authors: Mohammad Reza Mohammadi, Layegheh Daliri
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Introduction: Leishmaniasis occurs in infectious diseases of Leishmania protozoa in Afghanistan, anthroponotic leishmaniasis and common cutaneous leishmaniasis (ZCL). Anthroponotic skin leishmania tropica may cause urban diseases and transmitted by Phlebotomus Sergenti. In different parts of Afghanistan, different species of Leishmania are observed. We report the epidemiological characteristics of prevention and treatment in this study. Methods: This study examines the epidemiology and prevention of religious diseases in Afghanistan. Knowledge gaps were analyzed and collected with our own data. Results: In Afghanistan, most of the Lishmania Tropic seekers are Four species of Leishmania in northern Afghanistan, including Leishmania Tropica, L. Major and L. Donovani, cause skin lesions, but L. Donovani and L. infantum are visible. Even combined prevention can significantly reduce the amount of infection. Conclusion: Skinny, as well as visceral leishmaniasis, can occur among the returnees from Afghanistan. Unusual and poor skin lesions can be created by L. Donovani. In most pathogenic areas, the transmission of common diseases between humans and animals. Home dogs are the main reservoir, transferring in some areas such as India and Sudan.Keywords: leishmania donovani, leishmania tropica, treatment, disease, epidemiology
Procedia PDF Downloads 1822388 On Boundary Value Problems of Fractional Differential Equations Involving Stieltjes Derivatives
Authors: Baghdad Said
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Differential equations of fractional order have proved to be important tools to describe many physical phenomena and have been used in diverse fields such as engineering, mathematics as well as other applied sciences. On the other hand, the theory of differential equations involving the Stieltjes derivative (SD) with respect to a non-decreasing function is a new class of differential equations and has many applications as a unified framework for dynamic equations on time scales and differential equations with impulses at fixed times. The aim of this paper is to investigate the existence, uniqueness, and generalized Ulam-Hyers-Rassias stability (UHRS) of solutions for a boundary value problem of sequential fractional differential equations (SFDE) containing (SD). This study is based on the technique of noncompactness measures (MNCs) combined with Monch-Krasnoselski fixed point theorems (FPT), and the results are proven in an appropriate Banach space under sufficient hypotheses. We also give an illustrative example. In this work, we introduced a class of (SFDE) and the results are obtained under a few hypotheses. Future directions connected to this work could focus on another problem with different types of fractional integrals and derivatives, and the (SD) will be assumed under a more general hypothesis in more general functional spaces.Keywords: SFDE, SD, UHRS, MNCs, FPT
Procedia PDF Downloads 412387 Informing Lighting Designs Through a Comprehensive Review of Light Pollution Impacts
Authors: Stephen M. Simmons, Stuart W. Baur, William L. Gillis
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In recent years, increasing concern has been shown towards the issue of light pollution, especially with the spread of brighter, more blue-rich LED bulbs. Much research has been conducted in order to study the effects of artificial light at night, and many adverse impacts have been discovered, such as circadian disruption, degradation of the night sky, and interference oftheprocesses and behaviors of plants and animals. Despite a plethora of informationin the literature regarding the numerous illeffects of this type of pollution, there does not appear to be a complete summary of these impacts, including their magnitudes, which would facilitate the balancing of risks and benefits in the design of an exterior lighting system. This paperprovides a comprehensive review of the known impacts of light pollution, divided into four categories - human health, night sky, plants, and animals; additionally, it includes a synopsis of what likely remains unknown at this point in time. This review will attempt to showcase the relative significance of differentimpacts within each category, as well as their sensitivity to changes in lighting specifications (brightness, color temperature, shielding, and mounting height). Methods to be employed in this research include an extensive literature review and the gathering of expert knowledge and opinions. The findings of this review will be used to inform the creation of an optimized lighting design for the Missouri University of Science and Technology campus. It is hoped that future research willexplore the known impacts of light pollution further, as well as search for what still remains to be found regarding the consequencesof artificial light at night.Keywords: comprehensive review, impacts, light pollution, lighting design, literature review
Procedia PDF Downloads 1372386 The Effects of Sous Vide Technology Combined with Different Herbals on Sensorial and Physical Quality of Fish Species Caught in the Northern Aegean Sea and Marmara Sea
Authors: Zafer Ceylan, Gülgün F.Unal Şengör, Onur Gönülal
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In this study, sous vide technology were treated with different herbs into different fish species which were caught from northern Aegean and Marmara Sea. Before samples were packaged under vacuum, herbs had been cut and added at the same ratio into the package. Samples were sliced, the weight of each sample was about 150 g, and packaged under vacuum. During the storage period at 4ºC, taste, odor, texture properties of fish samples treated with sous vide were evaluated by trained panelists. Meanwhile, the effect of different herbs on pH values of the samples was investigated. These results were correlated with sensorial results. Furthermore, the effects of different herbs on L, a, b values of fish samples treated with sous vide were evaluated by color measurement. All sensorial results indicated that the values of samples treated with herbs were higher than that of the control group. Color measurement results and pH values were found parallel with sensorial results.Keywords: Sous vide, fish, herbs, consumer preferences, pH, color measurement
Procedia PDF Downloads 4942385 Resilience Perspective on Response Strategies for Super-Standard Rain and Flood Disasters: A Case Study of the “Zhengzhou 7.20 Heavy Rain” Event
Authors: Luojie Tang
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The article takes the "7.20 Heavy Rainstorm in Zhengzhou" as a starting point, collects relevant disaster data, reproduces the entire process of the disaster, and identifies the main problems exposed by the city in responding to super-standard rain and flood disasters. Based on the review of resilience theory, the article proposes a shift in thinking about the response to super-standard rain and flood disasters from the perspective of resilience, clarifies the differences in the emphasis on resilience at different stages of disasters, and preliminarily constructs a response system for super-standard rain and flood disasters based on the guidance of resilience theory. Finally, combined with the highlighted problems in the 7.20 Heavy Rainstorm in Zhengzhou, the article proposes targeted response strategies from three perspectives: institutional management, technological support, and infrastructure, under the perspective of resilience.Keywords: resilient city, exceedance-based stormwater management, disaster risk reduction, megalopolis
Procedia PDF Downloads 1142384 Real-Time Sensor Fusion for Mobile Robot Localization in an Oil and Gas Refinery
Authors: Adewole A. Ayoade, Marshall R. Sweatt, John P. H. Steele, Qi Han, Khaled Al-Wahedi, Hamad Karki, William A. Yearsley
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Understanding the behavioral characteristics of sensors is a crucial step in fusing data from several sensors of different types. This paper introduces a practical, real-time approach to integrate heterogeneous sensor data to achieve higher accuracy than would be possible from any one individual sensor in localizing a mobile robot. We use this approach in both indoor and outdoor environments and it is especially appropriate for those environments like oil and gas refineries due to their sparse and featureless nature. We have studied the individual contribution of each sensor data to the overall combined accuracy achieved from the fusion process. A Sequential Update Extended Kalman Filter(EKF) using validation gates was used to integrate GPS data, Compass data, WiFi data, Inertial Measurement Unit(IMU) data, Vehicle Velocity, and pose estimates from Fiducial marker system. Results show that the approach can enable a mobile robot to navigate autonomously in any environment using a priori information.Keywords: inspection mobile robot, navigation, sensor fusion, sequential update extended Kalman filter
Procedia PDF Downloads 4732383 3D Printing of Cold Atmospheric Plasma Treated Poly(ɛ-Caprolactone) for Bone Tissue Engineering
Authors: Dong Nyoung Heo, Il Keun Kwon
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Three-dimensional (3D) technology is a promising method for bone tissue engineering. In order to enhance bone tissue regeneration, it is important to have ideal 3D constructs with biomimetic mechanical strength, structure interconnectivity, roughened surface, and the presence of chemical functionality. In this respect, a 3D printing system combined with cold atmospheric plasma (CAP) was developed to fabricate a 3D construct that has a rough surface with polar functional chemical groups. The CAP-etching process leads to oxidation of chemical groups existing on the polycaprolactone (PCL) surface without conformational change. The surface morphology, chemical composition, mean roughness of the CAP-treated PCL surfaces were evaluated. 3D printed constructs composed of CAP-treated PCL showed an effective increment in the hydrophilicity and roughness of the PCL surface. Also, an in vitro study revealed that CAP-treated 3D PCL constructs had higher cellular behaviors such as cell adhesion, cell proliferation, and osteogenic differentiation. Therefore, a 3D printing system with CAP can be a highly useful fabrication method for bone tissue regeneration.Keywords: bone tissue engineering, cold atmospheric plasma, PCL, 3D printing
Procedia PDF Downloads 1142382 Keyloggers Prevention with Time-Sensitive Obfuscation
Authors: Chien-Wei Hung, Fu-Hau Hsu, Chuan-Sheng Wang, Chia-Hao Lee
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Nowadays, the abuse of keyloggers is one of the most widespread approaches to steal sensitive information. In this paper, we propose an On-Screen Prompts Approach to Keyloggers (OSPAK) and its analysis, which is installed in public computers. OSPAK utilizes a canvas to cue users when their keystrokes are going to be logged or ignored by OSPAK. This approach can protect computers against recoding sensitive inputs, which obfuscates keyloggers with letters inserted among users' keystrokes. It adds a canvas below each password field in a webpage and consists of three parts: two background areas, a hit area and a moving foreground object. Letters at different valid time intervals are combined in accordance with their time interval orders, and valid time intervals are interleaved with invalid time intervals. It utilizes animation to visualize valid time intervals and invalid time intervals, which can be integrated in a webpage as a browser extension. We have tested it against a series of known keyloggers and also performed a study with 95 users to evaluate how easily the tool is used. Experimental results made by volunteers show that OSPAK is a simple approach.Keywords: authentication, computer security, keylogger, privacy, information leakage
Procedia PDF Downloads 1222381 Mitigating Acid Mine Drainage Pollution: A Case Study In the Witwatersrand Area of South Africa
Authors: Elkington Sibusiso Mnguni
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In South Africa, mining has been a key economic sector since the discovery of gold in 1886 in the Witwatersrand region, where the city of Johannesburg is located. However, some mines have since been decommissioned, and the continuous pumping of acid mine drainage (AMD) also stopped causing the AMD to rise towards the ground surface. This posed a serious environmental risk to the groundwater resources and river systems in the region. This paper documents the development and extent of the environmental damage as well as the measures implemented by the government to alleviate such damage. The study will add to the body of knowledge on the subject of AMD treatment to prevent environmental degradation. The method used to gather and collate relevant data and information was the desktop study. The key findings include the social and environmental impact of the AMD, which include the pollution of water sources for domestic use leading to skin and other health problems and the loss of biodiversity in some areas. It was also found that the technical intervention of constructing a plant to pump and treat the AMD using the high-density sludge technology was the most effective short-term solution available while a long-term solution was being explored. Some successes and challenges experienced during the implementation of the project are also highlighted. The study will be a useful record of the current status of the AMD treatment interventions in the region.Keywords: acid mine drainage, groundwater resources, pollution, river systems, technical intervention, high density sludge
Procedia PDF Downloads 1862380 Protection of Cultural Heritage against the Effects of Climate Change Using Autonomous Aerial Systems Combined with Automated Decision Support
Authors: Artur Krukowski, Emmanouela Vogiatzaki
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The article presents an ongoing work in research projects such as SCAN4RECO or ARCH, both funded by the European Commission under Horizon 2020 program. The former one concerns multimodal and multispectral scanning of Cultural Heritage assets for their digitization and conservation via spatiotemporal reconstruction and 3D printing, while the latter one aims to better preserve areas of cultural heritage from hazards and risks. It co-creates tools that would help pilot cities to save cultural heritage from the effects of climate change. It develops a disaster risk management framework for assessing and improving the resilience of historic areas to climate change and natural hazards. Tools and methodologies are designed for local authorities and practitioners, urban population, as well as national and international expert communities, aiding authorities in knowledge-aware decision making. In this article we focus on 3D modelling of object geometry using primarily photogrammetric methods to achieve very high model accuracy using consumer types of devices, attractive both to professions and hobbyists alike.Keywords: 3D modelling, UAS, cultural heritage, preservation
Procedia PDF Downloads 1232379 Improvement Anaerobic Digestion Performance of Sewage Sludge by Co-Digestion with Cattle Manure
Authors: Raouf Hassan
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Biogas energy production from sewage sludge is an economically feasible and eco-friendly in nature. Sewage sludge is considered nutrient-rich substrates, but had lower values of carbone which consider an energy source for anaerobic bacteria. The lack or lower values of carbone-to-nitrogen ratio (C/N) reduced biogas yield and fermentation rate. Anaerobic co-digestion of sewage sludge offers several benefits over mono-digestion such as optimize nutrient balance, increased cost-efficiency and increased degradation rate. The high produced amounts of animal manures, which reach up to 90% of the total collected organic wastes, are recommended for the co-digestion with sewage sludge, especially with the limitations of industrial substrates. Moreover, cattle manures had high methane production potential (500 m3/t vsadded). When mixed with sewage sludge the potential methane production increased with increasing cattle manure content. In this paper, the effect of cattle manure (CM) addition as co-substrates on the sewage sludge (SS) anaerobic digestion performance was investigated under mesophilic conditions (35°C) using anaerobic batch reactors. The batch reactors were operated with a working volume 0.8 liter, and a hydraulic retention time of 30 days. The research work focus on studying two main parameters; the biogas yield (expressed as VSS) and pH values inside the reactors.Keywords: anaerobic digestion, sewage sludge, cattle manure, mesophilic, biogas yield, pH
Procedia PDF Downloads 3152378 Corrosion Resistance Evaluation of Reinforcing Bars: A Comparative Study of Fusion Bonded Epoxy Coated, Cement Polymer Composite Coated and Dual Zinc Epoxy Coated Rebar for Application in Reinforced Concrete Structures
Authors: Harshit Agrawal, Salman Muhammad
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Degradation to reinforced concrete (RC), primarily due to corrosion of embedded reinforcement, has been a major cause of concern worldwide. Among several ways to control corrosion, the use of coated reinforcement has gained significant interest in field applications. However, the choice of proper coating material and the effect of damage over coating are yet to be addressed for effective application of coated reinforcements. The present study aims to investigate and compare the performance of three different types of coated reinforcements —Fusion-Bonded Epoxy Coating (FBEC), Cement Polymer Composite Coating (CPCC), and Dual Zinc-Epoxy Coating (DZEC) —in concrete structures. The aim is to assess their corrosion resistance, durability, and overall effectiveness as coated reinforcement materials both in undamaged and simulated damaged conditions. Through accelerated corrosion tests, electrochemical analysis, and exposure to aggressive marine environments, the study evaluates the long-term performance of each coating system. This research serves as a crucial guide for engineers and construction professionals in selecting the most suitable corrosion protection for reinforced concrete, thereby enhancing the durability and sustainability of infrastructure.Keywords: corrosion, reinforced concrete, coated reinforcement, seawater exposure, electrochemical analysis, service life, corrosion prevention
Procedia PDF Downloads 832377 Operational Challenges of Marine Fiber Reinforced Polymer Composite Structures Coupled with Piezoelectric Transducers
Authors: H. Ucar, U. Aridogan
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Composite structures become intriguing for the design of aerospace, automotive and marine applications due to weight reduction, corrosion resistance and radar signature reduction demands and requirements. Studies on piezoelectric ceramic transducers (PZT) for diagnostics and health monitoring have gained attention for their sensing capabilities, however PZT structures are prone to fail in case of heavy operational loads. In this paper, we develop a piezo-based Glass Fiber Reinforced Polymer (GFRP) composite finite element (FE) model, validate with experimental setup, and identify the applicability and limitations of PZTs for a marine application. A case study is conducted to assess the piezo-based sensing capabilities in a representative marine composite structure. A FE model of the composite structure combined with PZT patches is developed, afterwards the response and functionality are investigated according to the sea conditions. Results of this study clearly indicate the blockers and critical aspects towards industrialization and wide-range use of PZTs for marine composite applications.Keywords: FRP composite, operational challenges, piezoelectric transducers, FE modeling
Procedia PDF Downloads 1742376 Combined Model Predictive Controller Technique for Enhancing NAO Gait Stabilization
Authors: Brahim Brahmi, Mohammed Hamza Laraki, Mohammad Habibur Rahman, Islam M. Rasedul, M. Assad Uz-Zaman
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The humanoid robot, specifically the NAO robot must be able to provide a highly dynamic performance on the soccer field. Maintaining the balance of the humanoid robot during the required motion is considered as one of a challenging problems especially when the robot is subject to external disturbances, as contact with other robots. In this paper, a dynamic controller is proposed in order to ensure a robust walking (stabilization) and to improve the dynamic balance of the robot during its contact with the environment (external disturbances). The generation of the trajectory of the center of mass (CoM) is done by a model predictive controller (MPC) conjoined with zero moment point (ZMP) technique. Taking into account the properties of the rotational dynamics of the whole-body system, a modified previous control mixed with feedback control is employed to manage the angular momentum and the CoM’s acceleration, respectively. This latter is dedicated to provide a robust gait of the robot in the presence of the external disturbances. Simulation results are presented to show the feasibility of the proposed strategy.Keywords: preview control, Nao robot, model predictive control
Procedia PDF Downloads 1282375 Development of Surface-Enhanced Raman Spectroscopy-Active Gelatin Based Hydrogels for Label Free Detection of Bio-Analytes
Authors: Zahra Khan
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Hydrogels are a macromolecular network of hydrophilic copolymers with physical or chemical cross-linking structures with significant water uptake capabilities. They are a promising substrate for surface-enhanced Raman spectroscopy (SERS) as they are both flexible and biocompatible materials. Conventional SERS-active substrates suffer from limitations such as instability and inflexibility, which restricts their use in broader applications. Gelatin-based hydrogels have been synthesised in a facile and relatively quick method without the use of any toxic cross-linking agents. Composite gel material was formed by combining the gelatin with simple polymers to enhance the functional properties of the gel. Gold nanoparticles prepared by a reproducible seed-mediated growth method were combined into the bulk material during gel synthesis. After gel formation, the gel was submerged in the analyte solution overnight. SERS spectra were then collected from the gel using a standard Raman spectrometer. A wide range of analytes was successfully detected on these hydrogels showing potential for further optimization and use as SERS substrates for biomedical applications.Keywords: gelatin, hydrogels, flexible materials, SERS
Procedia PDF Downloads 1122374 Enhance Engineering Pedagogy in Programming Course via Knowledge Graph-Based Recommender System
Authors: Yan Li
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Purpose: There is a lack of suitable recommendation systems to assist engineering teaching. The existing traditional engineering pedagogies lack learning interests for postgraduate students. The knowledge graph-based recommender system aims to enhance postgraduate students’ programming skills, with a focus on programming courses. Design/methodology/approach: The case study will be used as a major research method, and the two case studies will be taken in both two teaching styles of the universities (Zhejiang University and the University of Nottingham Ningbo China), followed by the interviews. Quantitative and qualitative research methods will be combined in this study. Research limitations/implications: The case studies were only focused on two teaching styles universities, which is not comprehensive enough. The subject was limited to postgraduate students. Originality/value: The study collected and analyzed the data from two teaching styles of universities’ perspectives. It explored the challenges of Engineering education and tried to seek potential enhancement.Keywords: knowledge graph and recommender system, engineering pedagogy, programming skills, postgraduate students
Procedia PDF Downloads 742373 Hyaluronic Acid Binding to Link Domain of Stabilin-2 Receptor
Authors: Aleksandra Twarda, Dobrosława Krzemień, Grzegorz Dubin, Tad A. Holak
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Stabilin-2 belongs to the group of scavenger receptors and plays a crucial role in clearance of more than 10 ligands from the bloodstream, including hyaluronic acid, products of degradation of extracellular matrix and metabolic products. The Link domain, a defining feature of stabilin-2, has a sequence similar to Link domains in other hyaluronic acid receptors, such as CD44 or TSG-6, and is responsible for most of ligands binding. Present knowledge of signal transduction by stabilin-2, as well as ligands’ recognition and binding mechanism, is limited. Until now, no experimental structures have been solved for any segments of stabilin-2. It has recently been demonstrated that the stabilin-2 knock-out or blocking of the receptor by an antibody effectively opposes cancer metastasis by elevating the level of circulating hyaluronic acid. Moreover, loss of expression of stabilin-2 in a peri-tumourous liver correlates with increased survival. Solving of the crystal structure of stabilin-2 and elucidation of the binding mechanism of hyaluronic acid could enable the precise characterization of the interactions in the binding site. These results may allow for designing specific small-molecule inhibitors of stabilin-2 that could be used in cancer therapy. To carry out screening for crystallization of stabilin-2, we cloned constructs of the Link domain of various lengths with or without surrounding domains. The folding properties of the constructs were checked by nuclear magnetic resonance (NMR). It is planned to show the binding of hyaluronic acid to the Link domain using several biochemical methods, i.a. NMR, isothermal titration calorimetry and fluorescence polarization assay.Keywords: stabilin-2, Link domain, X-ray crystallography, NMR, hyaluronic acid, cancer
Procedia PDF Downloads 4032372 Heritage Tourism Balance between Historic Culture and Marketing Innovation: The Case Study of Taiwan
Authors: Lin Chih-Ken
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This paper explores the A Li Shan hotel of Taiwan during the Japanese occupation period, after over a hundred years of time, it has been handed over to the hotel managing enterprise to retain the historic building and the culture. Applying the innovative marketing strategies, coordinate the local government traveling policy then combined local tea agriculture and forestry specialty integrated marketing, to create the special hotel located in the Alishan National Scenic Area with the characteristics of landscape, innovative marketing and history, to attract domestic tourism and visitors around the world. This study interview the hotel owner, managers, employees and guests, in addition to collected message feedback from reservation website, to apply Ambidexterity Marketing Theory and Resource Base Theory to analyze the main impact factors. The conclusion showed that the integration of several key factors and make good use of resource strength generate heterogeneous product characteristics to attracting wider range of visitors.Keywords: heritage tourism, historic hotel, marketing ambidexterity, resource base theory
Procedia PDF Downloads 2652371 A Macroeconomic Analysis of Defense Industry: Comparisons, Trends and Improvements in Brazil and in the World
Authors: J. Fajardo, J. Guerra, E. Gonzales
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This paper will outline a study of Brazil's industrial base of defense (IDB), through a bibliographic research method, combined with an analysis of macroeconomic data from several available public data platforms. This paper begins with a brief study about Brazilian national industry, including analyzes of productivity, income, outcome and jobs. Next, the research presents a study on the defense industry in Brazil, presenting the main national companies that operate in the aeronautical, army and naval branches. After knowing the main points of the Brazilian defense industry, data on the productivity of the defense industry of the main countries and competing companies of the Brazilian industry were analyzed, in order to summarize big cases in Brazil with a comparative analysis. Concerned the methodology, were used bibliographic research and the exploration of historical data series, in order to analyze information, to get trends and to make comparisons along the time. The research is finished with the main trends for the development of the Brazilian defense industry, comparing the current situation with the point of view of several countries.Keywords: economics of defence, industry, trends, market
Procedia PDF Downloads 1562370 Fracture Energy Corresponding to the Puncture/Cutting of Nitrile Rubber by Pointed Blades
Authors: Ennouri Triki, Toan Vu-Khanh
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Resistance to combined puncture/cutting by pointed blades is an important property of gloves materials. The purpose of this study is to propose an approach derived from the fracture mechanics theory to calculate the fracture energy associated to the puncture/cutting of nitrile rubber. The proposed approach is also based on the application of a sample pre-strained during the puncture/cutting test in order to remove the contribution of friction. It was validated with two different pointed blade angles of 22.5° and 35°. Results show that the applied total fracture energy corresponding to puncture/cutting is controlled by three energies, one is the fracture energy or the intrinsic strength of the material, the other reflects the friction energy between a pointed blade and the material. For an applied pre-strain energy (or tearing energy) of high value, the friction energy is completely removed. Without friction, the total fracture energy is constant. In that case, the fracture contribution of the tearing energy is marginal. Growth of the crack is thus completely caused by the puncture/cutting by a pointed blade. Finally, results suggest that the value of the fracture energy corresponding to puncture/cutting by pointed blades is obtained at a frictional contribution of zero.Keywords: elastomer, energy, fracture, friction, pointed blades
Procedia PDF Downloads 3062369 CFD Simulation for Flow Behavior in Boiling Water Reactor Vessel and Upper Pool under Decommissioning Condition
Authors: Y. T. Ku, S. W. Chen, J. R. Wang, C. Shih, Y. F. Chang
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In order to respond the policy decision of non-nuclear homes, Tai Power Company (TPC) will provide the decommissioning project of Kuosheng Nuclear power plant (KSNPP) to meet the regulatory requirement in near future. In this study, the computational fluid dynamics (CFD) methodology has been employed to develop a flow prediction model for boiling water reactor (BWR) with upper pool under decommissioning stage. The model can be utilized to investigate the flow behavior as the vessel combined with upper pool and continuity cooling system. At normal operating condition, different parameters are obtained for the full fluid area, including velocity, mass flow, and mixing phenomenon in the reactor pressure vessel (RPV) and upper pool. Through the efforts of the study, an integrated simulation model will be developed for flow field analysis of decommissioning KSNPP under normal operating condition. It can be expected that a basis result for future analysis application of TPC can be provide from this study.Keywords: CFD, BWR, decommissioning, upper pool
Procedia PDF Downloads 2672368 Proteomic Analysis of 2,4-Epibrassinolide Alleviating Low Temperature Stress in Rice Seedling Leaves
Authors: Jiang Xu, Daoping Wang, Qun Li, Yinghong Pan
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2,4-Epibrassinolide (EBR), which is a kind of plant hormone Brassinosteroids (BRs), is widely studied and applied in the global scale but the proteomic characteristics of EBR alleviating low temperature stress in rice seedling leaves are still not clear. In this study, seeding rice of Nipponbare were treated with EBR and distilled water, then stressed at 4℃ or 26 ℃, and analyzed by mass spectrometry analysis, verified by parallel reaction monitoring technique (PRM). The results showed that 5778 proteins were identified in total and 4834 proteins were identified with quantitative information. Among them, 401 up-regulated and 220 down-regulated proteins may be related to EBR alleviating low temperature stress in rice seedling leaves. The molecular functions of most of up-regulated proteins are RNA binding and hydrolase activity and are mainly enriched in the pathways of carbon metabolism, folic acid synthesis, and amino acid biosynthesis. The down-regulated proteins are mainly related to catalytic activity and oxidoreductase activity and are mainly enriched in the pathways of limonene and pinene degradation, riboflavin metabolism, porphyrin and chlorophyll metabolism, and other metabolic pathways. PRM validation and literature analysis showed that NADP-malic acidase, peroxidase, 3-phosphoglycerate dehydrogenase, enolase, glyceraldehyde-3- phosphate dehydrogenase and pyruvate kinase are closely related to the effect of EBR on low temperature stress. These results also suggested that BRs could relieve the effect of low temperature stress on rice seed germination in many ways.Keywords: 2, 4-Epibrassinolid, low temperature stress, proteomic analysis, rice
Procedia PDF Downloads 1612367 Thermochemical Study of the Degradation of the Panels of Wings in a Space Shuttle by Utilization of HSC Chemistry Software and Its Database
Authors: Ahmed Ait Hou
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The wing leading edge and nose cone of the space shuttle are fabricated from a reinforced carbon/carbon material. This material attains its durability from a diffusion coating of silicon carbide (SiC) and a glass sealant. During re-entry into the atmosphere, this material is subject to an oxidizing high-temperature environment. The use of thermochemical calculations resulting at the HSC CHEMISTRY software and its database allows us to interpret the phenomena of oxidation and chloridation observed on the wing leading edge and nose cone of the space shuttle during its mission in space. First study is the monitoring of the oxidation reaction of SiC. It has been demonstrated that thermal oxidation of the SiC gives the two compounds SiO₂(s) and CO(g). In the extreme conditions of very low oxygen partial pressures and high temperatures, there is a reaction between SiC and SiO₂, leading to SiO(g) and CO(g). We had represented the phase stability diagram of Si-C-O system calculated by the use of the HSC Chemistry at 1300°C. The principal characteristic of this diagram of predominance is the line of SiC + SiO₂ coexistence. Second study is the monitoring of the chloridation reaction of SiC. The other problem encountered in addition to oxidation is the phenomenon of chloridation due to the presence of NaCl. Indeed, after many missions, the leading edge wing surfaces have exhibited small pinholes. We have used the HSC Chemistry database to analyze these various reactions. Our calculations concorde with the phenomena we announced in research work resulting in NASA LEWIS Research center.Keywords: thermochchemicals calculations, HSC software, oxidation and chloridation, wings in space
Procedia PDF Downloads 1242366 Effects of Irrigation Applications during Post-Anthesis Period on Flower Development and Pyrethrin Accumulation in Pyrethrum
Authors: Dilnee D. Suraweera, Tim Groom, Brian Chung, Brendan Bond, Andrew Schipp, Marc E. Nicolas
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Pyrethrum (Tanacetum cinerariifolium) is a perennial plant belongs to family Asteraceae. This is cultivated commercially for extraction of natural insecticide pyrethrins, which accumulates in their flower head achenes. Approximately 94% of the pyrethrins are produced within secretory ducts and trichomes of achenes of the mature pyrethrum flower. This is the most widely used botanical insecticide in the world and Australia is the current largest pyrethrum producer in the world. Rainfall in pyrethrum growing regions in Australia during pyrethrum flowering period, in late spring and early summer is significantly less. Due to lack of adequate soil moisture and under elevated temperature conditions during post-anthesis period, resulting in yield reductions. Therefore, understanding of yield responses of pyrethrum to irrigation is important for Pyrethrum as a commercial crop. Irrigation management has been identified as a key area of pyrethrum crop management strategies that could be manipulated to increase yield. Pyrethrum is a comparatively drought tolerant plant and it has some ability to survive in dry conditions due to deep rooting. But in dry areas and in dry seasons, the crop cannot reach to its full yield potential without adequate soil moisture. Therefore, irrigation is essential during the flowering period prevent crop water stress and maximise yield. Irrigation during the water deficit period results in an overall increased rate of water uptake and growth by the plant which is essential to achieve the maximum yield benefits from commercial crops. The effects of irrigation treatments applied at post-anthesis period on pyrethrum yield responses were studied in two irrigation methods. This was conducted in a first harvest commercial pyrethrum field in Waubra, Victoria, during 2012/2013 season. Drip irrigation and overhead sprinkler irrigation treatments applied during whole flowering period were compared with ‘rainfed’ treatment in relation to flower yield and pyrethrin yield responses. The results of this experiment showed that the application of 180mm of irrigation throughout the post-anthesis period, from early flowering stages to physiological maturity under drip irrigation treatment increased pyrethrin concentration by 32%, which combined with the 95 % increase in the flower yield to give a total pyrethrin yield increase of 157%, compared to the ‘rainfed’ treatment. In contrast to that overhead sprinkler irrigation treatment increased pyrethrin concentration by 19%, which combined with the 60 % increase in the flower yield to give a total pyrethrin yield increase of 91%, compared to the ‘rainfed’ treatment. Irrigation treatments applied throughout the post-anthesis period significantly increased flower yield as a result of enhancement of number of flowers and flower size. Irrigation provides adequate soil moisture for flower development in pyrethrum which slows the rate of flower development and increases the length of the flowering period, resulting in a delayed crop harvest (11 days) compared to the ‘rainfed’ treatment. Overall, irrigation has a major impact on pyrethrin accumulation which increases the rate and duration of pyrethrin accumulation resulting in higher pyrethrin yield per flower at physiological maturity. The findings of this study will be important for future yield predictions and to develop advanced agronomic strategies to maximise pyrethrin yield in pyrethrum.Keywords: achene, drip irrigation, overhead irrigation, pyrethrin
Procedia PDF Downloads 4092365 Combining Impedance and Hydrodynamic Methods toward Hydrogen Evolution Reaction to Characterize Pt(pc), Pt5Gd, and Nanostructure Pd Electrocatalyst
Authors: Kun-Ting Song, Christian Schott, Peter Schneider, Sebastian Watzele, Regina Kluge, Elena Gubanova, Aliaksandr S. Bandarenka
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The combination of electrochemical impedance spectroscopy (EIS) and the hydrodynamic technique like rotation disc electrode (RDE) provides a critical method for quantitively investigating mechanisms of hydrogen evolution reaction (HER) in acidic and alkaline media. Pt5Gd represented higher HER activities than polycrystalline Pt (Pt(pc)) by means of the surface strain effects. The model of the equivalent electric circuit to fit the impedance data under the RDE configurations is developed. To investigate the relative reaction contribution, the ratio of the charge transfer reactions of the Volmer-Heyrovsky and Volmer-Tafel pathways on Pt and Pt5Gd electrodes is determined. The ratio remains comparably similar in acidic media, but it changes in alkaline media with Volmer–Heyrovsky pathway dominating. This combined approach of EIS and RDE can help to study the electrolyte effects and other essential reactions for electrocatalysis in future work.Keywords: hydrogen evolution reaction, electrochemical impedance spectroscopy, hydrodynamic methods, electrocatalysis, electrochemical interface
Procedia PDF Downloads 832364 Assessment of Drainage Water Quality in South Africa: Case Study of Vaal-Harts Irrigation Scheme
Authors: Josiah A. Adeyemo, Fred A. O. Otieno, Olumuyiwa I. Ojo
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South Africa is water-stressed being a semi-arid country with limited annual rainfall supply and a lack of perennial streams. The future implications of population growth combined with the uncertainty of climate change are likely to have significant financial, human and ecological impacts on already scarce water resources. The waste water from the drainage canals of the Vaal-Harts irrigation scheme (VHS) located in Jan Kempdorp, a farming community in South Africa, were investigated for possible irrigation re-use and their effects on the immediate environment. Three major drains within the scheme were identified and sampled. Drainage water samples were analysed to determine its characteristics. The water samples analyzed had pH values in the range of 5.5 and 6.4 which is below the normal range for irrigation water and very low to moderate salinity (electrical conductivity 0.09-0.82 dS/m). The adjusted sodium adsorption ratio values in all the samples were also very low (<0.2), indicating very low sodicity hazards. The nitrate concentration in most of the samples was high, ranging from 4.8 to 53 mg/l. The reuse of the drainage water for irrigation is possible, but with further treatment. Some suggestions were offered in the safe management of drainage water in VHS.Keywords: drainage canal, water quality, irrigation, pollutants, environment
Procedia PDF Downloads 3352363 The FINDRISC Score for Prediabetes and Diabetes Screening in Adult Libyan Males
Authors: Issam M Hajjaji, Adel Tajoury, Salah R Benhamid
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The MENA region has the highest prevalence of diabetes in the world. Various risk scores were developed, not all appropriate locally. The objective of this study is to apply the FINDRISC Score to adult Libyan males to determine its significance, sensitivity, specificity and Positive Predictive Values as an initial screening tool for type 2 diabetes, and suggest a cut-off point. Methods: 600 subjects answered the questionnaire at their place of work, and their waist, weight, height & BP were measured. Thereafter, after excluding those with known diabetes, an Oral Glucose Tolerance Test was done. Results: 414 subjects aged 19-78 completed the questionnaire and tests. 35 (8.4%) had impaired glucose tolerance (IGT) and 13 (3.1%) had diabetes (DM). The AUC-ROC for IGT was 0.614 (95% CI: 0.527-0.701), for DM 0.810 (95% CI: 0.709-0.911) and for both 0.689 (95% CI: 0.609-0.769). The Positive Predictive Value for a cut-off score of 5 were 15.5%, 11.7% & 5.7% for both conditions combined, prediabetes & diabetes respectively. The equivalent values for a cut-off score of 8 were 16.1%, 9.0% & 7.7%. The Negative Predictive Values were uniformly above 90%. Conclusions & Recommendations: The FINDRISC Score had a low predictive value for dysglycaemia in this sample and performed at a level of significance for IGT that is similar to other MENA countries, but did better for DM. A larger sample that included women is suggested, with a view of adjusting the Score to suit the local population.Keywords: diabetes, FINDRISK, Libya, prediabetes
Procedia PDF Downloads 1272362 Four-Week Plyometric and Resistance Training on Muscle Strength and Sprint Performance in Wheelchair Racing Athletes
Authors: K. Thawichai, R. Pornthep
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The purpose of this study was to compare the effects of a four week training period of combined plyometric and resistance training or resistance training alone on muscle strength and sprint performance in wheelchair racing athletes. The participants were sixteen healthy male wheelchair racing athletes of the Thai national team. All participants were randomly assignments into two groups in the plyometric and resistance training group (n = 8) performed plyometric exercises followed by resistance training, whereas the resistance training group (n = 8) performed static stretching and the same resistance training program. At baseline and after training all participants were tested on 1-RM bench press for muscle strength and 100-m cycling sprint performance. The results of this study show that the plyometric and resistance training group made significantly greater improvements in overall muscle strength and sprint performance than the resistance training group following training. In conclusion, these findings suggest that the addition of a four week plyometric and resistance training program more beneficial than resistance training alone on muscle strength and sprint performance in wheelchair racing athletes.Keywords: plyometric, resistance training, strength, sprint, wheelchair athletes
Procedia PDF Downloads 5382361 Planning Quality and Maintenance Activities in a Closed-Loop Serial Multi-Stage Manufacturing System under Constant Degradation
Authors: Amauri Josafat Gomez Aguilar, Jean Pierre Kenné
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This research presents the development of a self-sustainable manufacturing system from a circular economy perspective, structured by a multi-stage serial production system consisting of a series of machines under deterioration in charge of producing a single product and a reverse remanufacturing system constituted by the same productive systems of the first scheme and different tooling, fed by-products collected at the end of their life cycle, and non-conforming elements of the first productive scheme. Since the advanced production manufacturing system is unable to satisfy the customer's quality expectations completely, we propose the development of a mixed integer linear mathematical model focused on the optimal search and assignment of quality stations and preventive maintenance operation to the machines over a time horizon, intending to segregate the correct number of non-conforming parts for reuse in the remanufacturing system and thereby minimizing production, quality, maintenance, and customer non-conformance penalties. Numerical experiments are performed to analyze the solutions found by the model under different scenarios. The results showed that the correct implementation of a closed manufacturing system and allocation of quality inspection and preventive maintenance operations generate better levels of customer satisfaction and an efficient manufacturing system.Keywords: closed loop, mixed integer linear programming, preventive maintenance, quality inspection
Procedia PDF Downloads 86