Search results for: optimal planning and control
3119 High-Temperature Behavior of Boiler Steel by Friction Stir Processing
Authors: Supreet Singh, Manpreet Kaur, Manoj Kumar
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High temperature corrosion is an imperative material degradation method experienced in thermal power plants and other energy generation sectors. Metallic materials such as ferritic steels have special properties such as easy fabrication and machinibilty, low cost, but a serious drawback of these materials is the worsening in properties initiating from the interaction with the environments. The metallic materials do not endure higher temperatures for extensive period of time because of their poor corrosion resistance. Friction Stir Processing (FSP), has emerged as the potent surface modification means and control of microstructure in thermo mechanically heat affecting zones of various metal alloys. In the current research work, FSP was done on the boiler tube of SA 210 Grade A1 material which is regularly used by thermal power plants. The strengthening of SA210 Grade A1 boiler steel through microstructural refinement by Friction Stir Processing (FSP) and analyze the effect of the same on high temperature corrosion behavior. The high temperature corrosion performance of the unprocessed and the FSPed specimens were evaluated in the laboratory using molten salt environment of Na₂SO₄-82%Fe₂(SO₄). The unprocessed and FSPed low carbon steel Gr A1 evaluation was done in terms of microstructure, corrosion resistance, mechanical properties like hardness- tensile. The in-depth characterization was done by EBSD, SEM/EDS and X-ray mapping analyses with an aim to propose the mechanism behind high temperature corrosion behavior of the FSPed steel.Keywords: boiler steel, characterization, corrosion, EBSD/SEM/EDS/XRD, friction stir processing
Procedia PDF Downloads 2383118 Human Xanthine Oxidase Inhibitory Effect, in vivo Antioxidant Activity of Globularia alypum L. Extracts
Authors: N. Boussoualim, H. Trabsa, I. Krache, S. Aouachria, S. Boumerfeg, L. Arrar, A. Baghiani
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The aim of this study consisted in evaluating the antioxidant in vivo properties, anti-hemolytic and XOR inhibitory effect of Globularia alypum L. (GA) extracts. GA was submitted to extraction and fractionation to give crude (CrE), chloroformique (ChE), ethyle acetate (EAE) and aqueos (AqE) extracts. Total polyphenols contents of GA extracts were determined; EAE is the most rich in polyphenols (157,74±5,27 mg GAE/mg of extract). GA Extracts inhibited XO in a concentration-dependent manner, the EAE showed the highest inhibitory properties on the XOR activity (IC50=0,083±0,001 mg/ml), followed by CrE and ChE. The antioxidant activities of the CrE, EAE, and AqE were tested by an in vivo assay in mice, the plasma ability to inhibit DPPH radical was measured, The CrE was found to exhibit the greatest scavenger activity with 48.41±2.763%, followed by AqE and EAE (40.54±7.51% and 41.79±1.654%, respectively). Total antioxidant capacity of red blood cells was measured, from the kinetics of hemolysis obtained. The calculated HT50 reveal an extension of time for half hemolysis in all treated groups compared with the control group. CrE increase significantly HT50 (112,8±2,427). The hemolysis is lagged, indicating that endogenous antioxidants in the erythrocytes can trap radicals to protect them against free-radical-induced hemolysis. Antimicrobial activities of the extracts were determined by the disc diffusion method. Test microorganisms were; 4 Gram positive, 7 gram negative bacteria, most active extracts were EAE and CrE. We deduce a great relationship between the effect on the extracts antibacterial effect and their contents in flavonoid.Keywords: Globularia alypum, Xanthine oxidoreductase, in vivo-antioxidant activity, hemolysis, polyphenol
Procedia PDF Downloads 3353117 Clinical Outcomes of Critically Ill Patients with Sepsis Receiving Extended and Standard Meropenem Infusion in Malaysian Hospitals
Authors: Fahmi Hassan, Noorizan Abdul Aziz, Yahaya Hassan, Hazlinda Abu Hassan
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Sepsis incidence in critical care settings is a major problem in health care. Extended antibiotic infusion is thought to be superior to traditional dosing especially when treating critically ill patients with sepsis. We compared clinical outcomes of critically ill patients with sepsis receiving 30-minute meropenem infusion and three-hour meropenem infusion. A retrospective case-control study was conducted among septic patients treated with meropenem infusion in ICUs of three hospitals. Patients included in the study received either extended or standard meropenem infusion as per the practice of individual settings. Outcomes and clinical data were retrospectively collected from the electronic databases and patients’ files. A total of 108 patients received extended meropenem infusion while another 117 patients received standard meropenem infusion. Patients receiving the extended meropenem infusion were found to have a significantly lower shorter length of hospital and ICU stay. It was also found that among those receiving extended meropenem infusion, 54.7% (64/117) had a reduction of SAPS II score, while only 44% (48/108) of patients receiving standard meropenem infusion had reduced scores. This study will strengthen the evidence in using extended meropenem infusion as a standard practice in critical care settings. As this is the first study of its kind done in Malaysia, it proves that prolonged meropenem infusion may be beneficial to critically ill patients with sepsis. However, randomized clinical trials with large sample size should be carried out in local settings in order to minimize other confounders that may influence with the result of the study.Keywords: antibiotics, beta lactams, critical care, extended infusion, meropenem
Procedia PDF Downloads 4083116 Clonal Dissemination of Pseudomonas aeruginosa Isolates in Kermanshah Hospitals, West of Iran
Authors: Alisha Akya, Afsaneh salami
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Background and Objective: Pseudomonas aeruginosa is an opportunistic pathogen associated with nosocomial infections. One of the major concerns for the treatment of P. aeruginosa infections is its resistant to a variety of antibiotics. The purpose of this study was to assess the dissemination of p. aeruginosa isolates obtained from major hospitals in Kermanshah, west of Iran. Materials and Methods: Antibiotic susceptibility testing was performed using the minimal inhibitory concentrations. Mettalo-beta-lactamase was investigated using the double disk diffusion (DDST) test and PCR. Molecular typing was performed by pulsed-field gel electrophoresis (PFGE). Results: The 60 P. aeruginosa isolates, 30 (50%) were resistant to gentamicin, 38 (63/3%) to piperacilin, 42 (70%) to ceftazidime, and 45 (75%) to cefepime. Twenty-nine (48/3%) isolates were MBLs producer based on the DDST test. Five (8/3%) isolates were positive for VIM gene and 4 of them were from burn specimens. PFGE analysis among MBLs producers revealed 12 distinct genotype patterns. A pattern covering the highest number of strains was determined as the dominant clone. Conclusions: Our study showed that P. aeruginosa strains can be spread between patients in hospitals or acquired from different environmental sources. P. aeruginosa isolates were highly resistant to antibiotics and, therefore, the susceptibility of isolates to antibiotics should be tested before treatment. Given the clinical significance of MBLs producing isolates, identification of these organisms is essential in the hospitals in order to get a better therapeutic response and control of bacterial dissemination.Keywords: clonal dissemination, mettalo-beta-lactamase, Pseudomonas aeruginosa, PFGE
Procedia PDF Downloads 3263115 Synthesis and Characterisation of Starch-PVP as Encapsulation Material for Drug Delivery System
Authors: Nungki Rositaningsih, Emil Budianto
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Starch has been widely used as an encapsulation material for drug delivery system. However, starch hydrogel is very easily degraded during metabolism in human stomach. Modification of this material is needed to improve the encapsulation process in drug delivery system, especially for gastrointestinal drug. In this research, three modified starch-based hydrogels are synthesized i.e. Crosslinked starch hydrogel, Semi- and Full- Interpenetrating Polymer Network (IPN) starch hydrogel using Poly(N-Vinyl-Pyrrolidone). Non-modified starch hydrogel was also synthesized as a control. All of those samples were compared as biomaterials, floating drug delivery, and their ability in loading drug test. Biomaterial characterizations were swelling test, stereomicroscopy observation, Differential Scanning Calorimetry (DSC), and Fourier Transform Infrared Spectroscopy (FTIR). Buoyancy test and stereomicroscopy scanning were done for floating drug delivery characterizations. Lastly, amoxicillin was used as test drug, and characterized with UV-Vis spectroscopy for loading drug observation. Preliminary observation showed that Full-IPN has the most dense and elastic texture, followed by Semi-IPN, Crosslinked, and Non-modified in the last position. Semi-IPN and Crosslinked starch hydrogel have the most ideal properties and will not be degraded easily during metabolism. Therefore, both hydrogels could be considered as promising candidates for encapsulation material. Further analysis and issues will be discussed in the paper.Keywords: biomaterial, drug delivery system, interpenetrating polymer network, poly(N-vinyl-pyrrolidone), starch hydrogel
Procedia PDF Downloads 2513114 Morphological and Molecular Studies (ITS1) of Hydatid Cysts in Slaughtered Sheep in Mashhad Area
Authors: G. R. Hashemi Tabar, G. R. Razmi, F. Mirshekar
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Echinococcus granulosus have ten strains from G1 to G9. Each strain is related to special intermediated host. The morphology, epidemiology, treatment and control in these strains are different. There are many morphological and molecular methods to differentiate of Echinococcus strains. However, using both methods were provided better information about identification of each strain. The aim of study was to identify Echinococcus granulosus strain of hydrated cysts in slaughtered sheep using morphological and molecular methods in Mashhad area. In the present study, the infected liver and lung with hydatid cysts were collected and transferred to laboratory. The hydatid cyst liquid was extracted and morphological characters of rostellar hook protosclocies were measured using micrometer ocular. The total length of large blade length of large hooks, total length of small and blade length of small hooks, and number of hooks per protoscolex were 23± 0.3μm, 11.7±0.5 μm, 19.3±1.1 μm,8±1.1 and 33.7±0.7 μm, respectively. In molecular section of the study, DNA each samples was extracted with MBST Kit and development of PCR using special primers (EgF, EgR) which amplify fragment of ITS1 gen. The PCR product was digested with Bsh1236I enzyme. Based on pattern of PCR-RLFP results (four band forming), G1, G2 and G3 strain of Echinococcus granulosus were obtained. Differentiation of three strains was done using sequencing analysis and G1 strain was diagnosed. The agreement between the molecular results with morphometric characters of rosetellar hook was confirmed the presence of G1 strain of Echinococcus in the slaughtered sheep of Mashhad area.Keywords: Echinococcus granulosus, Hydatid cyst, PCR, sheep
Procedia PDF Downloads 5183113 Evaluation and Analysis of the Regulations of Health and Safety in the Construction Industry: A Case of Study in Skikda, Algeria
Authors: Khorief Ouissem, Sassi Boudmagh Souad, Mahimoud Aissa
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The health and safety problem in the construction companies has been a major subject of research in Algeria for many years. The latest statistics of the Algerian National Social Security Fund (CNAS) shows that a third of accidents recorded at the national level are originated from construction activities. It is becoming increasingly essential and urgent to investigate and address its causes in order to find measures to overcome the deficiencies in this area. Thus, this paper takes in investigating this problem through a study conducted in the city of Skikda, Algeria. The study was carried out through questionnaire where twenty construction companies were taking into consideration. First, the study identifies the regulations and the laws related to the health and safety in the construction sector in Algeria. Then it goes on to assess and evaluate the implementation of the identified regulations in the companies selected. The result of the assessment indicates that the majority of the construction companies considered do not meet the health and safety standards and regulations. To extract the main causes of the failure of the system to control this industry, the observations and the evaluation were analyzed using the 5M or Ichikawa diagram method. This method is based on identifying the causes of the problem in terms of purpose, the list of potential causes for families. These families often correspond to 5M (Labor, Material, Methods, Middle, and Management). Finally, having identified the primary motives, the present authors propose a list of actions to move towards a more controlled and effective health and safety system for the construction industry.Keywords: health and safety, construction industry, performance measurement, Algeria
Procedia PDF Downloads 3403112 Combined Application of Rice-Straw Biochar and Poultry Manure Promotes Nutrient Uptake and Yield of Capsicum Frutescens
Authors: Fawibe O. O., Mustafa A. A., Oyelakin A. S., Dada O. A., Ojo E. S.
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Field experiment was carried out during the cropping season of 2021 to examine the influence of the sole or combined application of rice-straw biochar and poultry manure on yield, nutrient uptake, and physiological attributes of Capsicum frutescens. The experiment was a randomized complete block design with five replicates. Treatments were 10 t/ha biochar (BC), 5 t/ha biochar + 5 t/ha poultry manure (BC+PM), 10 t/ha poultry manure (PM), and no amendment as the control (NA ). Parameters determined were fruit yield, aboveground biomass, macro and micro nutrients in leaves, antinutrients content, and pigments (chlorophyll a, chlorophyll b, and carotenoids) concentration. Data were analysed with one-way analysis of variance, while means were separated using Duncan’s Multiple Range Test at p<0.05. Soil amended with PM increased the nitrogen content of C. frutescens leaves by 40.9%, while polyphenol and phytic acid were reduced by 20.5% and 29.2%, respectively, compared with NA. Moreover, PM increased chlorophyll a and chlorophyll b by 91.9% and 16.4%, whereas proline was reduced by 31.3% compared with NA. However, PM and BC+PM had comparable influence on pigments, nutrients and antinutrients contents of C. frutescens. BC+PM significantly increased yield and aboveground biomass of C. frutescens by 52.9% and 99.2%, respectively, compared with NA. BC had no significant influence on the yield and nutrient uptake of C. frutescens compared with NA. In conclusion, sole application of poultry manure or combined with rice-straw biochar increased yield and nutrients availability in the leaves of C. frutescens.Keywords: capsicum frutescens, biochar, nutrient uptake, poultry manure, organic amendment
Procedia PDF Downloads 1013111 Investigating the Critical Drivers of Behavior: The Case of Online Taxi Services
Authors: Rosa Hendijani, Mohammadhesam Hajighasemi
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As of late, the sharing economy has become an important type of business model. Online taxi services are one example that has grown rapidly around the world. This study examines the factors influencing the use of online taxis as one form of IT-enabled sharing services based on the theory of planned behavior (TPB). Based on the theory of planned behavior, these factors can be divided into three categories, including the ones related to attitude (e.g., image and perceived usefulness), normative believes (e.g., subjective norms), and behavioral control (e.g., technology facilitating conditions and self-efficacy). Three other factors were also considered based on the literature, including perceived economic benefits, openness towards using shared services, and perceived availability. The effect of all these variables was tested both directly and indirectly through intention as the mediating variable. A survey method was used to test the research hypotheses. In total, 361 individuals partook in the study. The results of a multiple regression analysis on behavior showed that perceived economic benefits, compatibility, and subjective norms were important factors influencing behavior among online taxi users. In addition, intention partially mediated the effect of perceived economic benefits and compatibility on behavior. It can be concluded that perceived economic benefits, compatibility, and subjective norms are the three main factors that influence behavior among online taxi users.Keywords: collaborative consumption, IT-enabled sharing services model, online taxi, sharing economy, theory of planned behavior
Procedia PDF Downloads 1383110 Psychosocial Risks and Occupational Health in a Mexican Small and Medium-Sized Enterprises
Authors: Magdalena Escamilla Quintal, Thelma Cetina Canto, Cecilia Aguilar Ortega
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Due to the importance that people represent for companies, the setting of a clear control of the risks that threaten the health and the material and financial resources of workers is essential. It is irrelevant if the company is a small and medium-sized enterprise (SME) or a large multinational, or if it is in the construction or service sector. The risk prevention importance is related to a constitutional and human right that all people have; working in a risk-free environment to prevent accidents or illnesses that may influence their quality of life and the tranquility of their family. Therefore, the objective of this study was to determine the level of psychosocial risks (physical and emotional) of the employees of an SME. The participants of this study were 186 employees of a productive sector SME; 151 men and 35 women, all with an average age of 31.77 years. Their seniority inside the SME was between one month and 19.91 years. Ninety-six workers were from the production area, 28 from the management area, as well as 25 from the sales area and 40 from the supplies area. Ninety-three workers were found in Uman, 78 in Playa del Carmen, 11 in Cancun and seven in Cd. del Carmen. We found a statistically significant relationship between the burnout variable and the engagement and psychosomatic complaints as well as between the variables of sex, burnout and psychosomatic complaints. We can conclude that, for benefit of the SME, that there are low levels of burnout and psychosomatic complaints, the women experience major levels of burnout and the men show major levels of psychosomatic complaints. The findings, contributions, limitations and future proposals will be analyzed.Keywords: psychosocial risks, SME, burnout, engagement, psychosomatic complaints
Procedia PDF Downloads 3673109 Prevention of COVID-19 Using Herbs and Natural Products
Authors: Nada Alqadri, Omaima Nasir
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Natural compounds are an important source of potential inhibitors; they have a lot of pharma potential with less adverse effects. The effective antiviral activities of natural products have been proved in different studies. The outbreak of COVID-19 in Wuhan, Hubei, in December 2019, coronavirus has had a significant impact on people's health and lives. Based on previous studies, natural products can be introduced as preventive and therapeutic agents in the fight against COVID-19; considering that no food or supplement has been authorized to prevent COVID-19, individuals continue to search for and consume specific herbs, foods, and commercial supplements for this purpose. This study will be aimed to estimate the uses of herbal and natural products during the COVID-19 infection to determine their usage reasons and evaluate their potential side effects. An online cross-sectional survey of different participants will be conducted and will be a focus on respondents’ chronic disease histories, socio-dmographic characteristics, and frequency and trends of using these products. Descriptive and univariate analyses will be performed to determine prevalence and associations between various products used and respondents’ socio-demographic data. Relationships will be tested using Pearson’s chi-square test or an exact probability test. Our main findings will give evidence of beneficial uses of natural products and herbal medicine as prophylactic and will be a vigorous approach to stop or at least slow down COVID-19 infection and transmission. This will be of great interest of public health, and the results of our study will lend health officials better control on the current pandemic.Keywords: COVID-19, herbs, natural products, saudi arabia
Procedia PDF Downloads 2183108 The Effect Training Program on Mixed Contractions on Both the Maximum Force and Explosive Force of the Lower Limbs Conducted Study to the Football Players Under the Age of 17 Years-Tiaret, Algeria
Authors: Saidia Houari
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The game of football is one of the global sports activities that have witnessed a remarkable development in recent years in the physical, technical, rhetorical and psychological aspects, so the modern play in different teams and international teams quickly and forcefully in the exact technical performance, and this is due to the interest of international coaches. The good training of the players during the youth stage at the level of various aspects to develop all the techniques that have a great effectiveness in competitions according to scientific methods studied. The muscle strength plays a very important role achieving the performance player during the game and it is clear the need for the player in many situations, especially when jumping to hit the ball head or the goal on the goal or long passes of different types and in the performance of various skills by force and speed appropriate to the possession of the ball or the control of the court of the court while overcoming the body weight during the game it is known that the stronger the muscles of the athlete and the reduced joints injuries, and the strength increases energy saving such as Latin phosphate and glycogen, and develop the player for a game football volitional qualities of the most important of courage, determination And self-confidence. There are also some skill movements that can not be performed without a certain level of strength, so the development of power may affect the effectiveness of the long-term training system.Keywords: trainning program, maximum force and expolosive force, lowers limbs, under 17 years
Procedia PDF Downloads 1043107 Advancing Our Understanding of Age-Related Changes in Executive Functions: Insights from Neuroimaging, Genetics and Cognitive Neurosciences
Authors: Yasaman Mohammadi
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Executive functions are a critical component of goal-directed behavior, encompassing a diverse set of cognitive processes such as working memory, cognitive flexibility, and inhibitory control. These functions are known to decline with age, but the precise mechanisms underlying this decline remain unclear. This paper provides an in-depth review of recent research investigating age-related changes in executive functions, drawing on insights from neuroimaging, genetics, and cognitive neuroscience. Through an interdisciplinary approach, this paper offers a nuanced understanding of the complex interplay between neural mechanisms, genetic factors, and cognitive processes that contribute to executive function decline in aging. Here, we investigate how different neuroimaging methods, like functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), have helped scientists better understand the brain bases for age-related declines in executive function. Additionally, we discuss the role of genetic factors in mediating individual differences in executive functions across the lifespan, as well as the potential for cognitive interventions to mitigate age-related decline. Overall, this paper presents a comprehensive and integrative view of the current state of knowledge regarding age-related changes in executive functions. It underscores the need for continued interdisciplinary research to fully understand the complex and dynamic nature of executive function decline in aging, with the ultimate goal of developing effective interventions to promote healthy cognitive aging.Keywords: executive functions, aging, neuroimaging, cognitive neuroscience, working memory, cognitive training
Procedia PDF Downloads 673106 Radioprotective Effects of Selenium and Vitamin-E against 6Mv X-Rays in Human Volunteers Blood Lymphocytes by Micronuclei Assay
Authors: Vahid Changizi, Aram Rostami, Akbar Mosavi
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Purpose of study: Critical macromolecules of cells such as DNA are in exposure to damage of free radicals that induced from interaction of ionizing radiation with biological systems. Selenium and vitamin-E are natural compound that has been shown to be a direct free radical scavenger. The aim of this study was to investigate the in vivo/in vitro radioprotective effect of selenium and vitamin-E separately and synergistically against genotoxicity induced by 6MV x-rays irradiation in cultured blood lymphocytes from 15 human volunteers. Methods: Fifteen volunteers were divided in three groups include A, B and C. These groups were given slenium(800 IU), vitamin-E(100 mg) and selenium(400 IU) + vitamin-E(50 mg), respectively. Peripheral blood samples were collected from each group before(0 hr) and 1, 2 and 3 hr after selenium and vitamin-E administration (separately and synergistically). Then the blood samples were irradiated to 200 cGy of 6 Mv x-rays. After that, lymphocyte samples were cultured with mitogenic stimulation to determine the chromosomal aberrations wih micronucleus assay in cytokinesis-blocked binucleated cells. Results: The lymphocytes in the blood samples collected at 1 hr after ingestion selenium and vitamin-E, exposed in vitro to x-rays exhibited a significant decrease in the incidence of micronuclei, compared with control group at 0 hr. The maximum protection and decrease in frequency of micronuclei(50%) was observed at 1 hr after administration of selenium and vitamin-E synergistically. Conclusion: The data suggest that ingestion of selenium and vitamin-E as a radioprotector substances before exposures may reduce genetic damage caused by x-rays irradiation.Keywords: x-rays, selenium, vitamin-e, lymphocyte, micronuclei
Procedia PDF Downloads 2673105 Study on Heat Transfer Capacity Limits of Heat Pipe with Working Fluids Ammonia and Water
Authors: M. Heydari, A. Ghanami
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Heat pipe is simple heat transfer device which combines the conduction and phase change phenomena to control the heat transfer without any need for external power source. At hot surface of heat pipe, the liquid phase absorbs heat and changes to vapor phase. The vapor phase flows to condenser region and with the loss of heat changes to liquid phase. Due to gravitational force the liquid phase flows to evaporator section. In HVAC systems the working fluid is chosen based on the operating temperature. The heat pipe has significant capability to reduce the humidity in HVAC systems. Each HVAC system which uses heater, humidifier or dryer is a suitable nominate for the utilization of heat pipes. Generally heat pipes have three main sections: condenser, adiabatic region, and evaporator. Performance investigation and optimization of heat pipes operation in order to increase their efficiency is crucial. In the present article, a parametric study is performed to improve the heat pipe performance. Therefore, the heat capacity of heat pipe with respect to geometrical and confining parameters is investigated. For the better observation of heat pipe operation in HVAC systems, a CFD simulation in Eulerian- Eulerian multiphase approach is also performed. The results show that heat pipe heat transfer capacity is higher for water as working fluid with the operating temperature of 340 K. It is also showed that the vertical orientation of heat pipe enhances it’s heat transfer capacity.used in the abstract.Keywords: heat pipe, HVAC system, grooved heat pipe, heat pipe limits
Procedia PDF Downloads 4003104 Secret Agents in the Azores during the Second World War and the Impact of Espionage on Portuguese-British Relations
Authors: Marisa Galiza Filipe
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In 1942, at the height of the Second World War, Roosevelt and Churchill planned to occupy the Azores to establish air and naval bases. The islands' privileged position in the middle of the Atlantic made them a strategic location for both the Axis and the Allies. For the Germans, the occupation of the island was also a strategic place to launch an attack on the United States of America, and for the British and Americans, the islands were the perfect spot to counterattack the German sinking of British boats and submarines. Salazar avoided the concession of the islands until 1943, claiming, on the one hand, the policy of neutrality, a decision made in agreement with England, and on the other hand, the reaffirmation of Portuguese sovereignty over the territory. Aware of the constant changes and supported by a network of informers on the islands, the German and British spies played a crucial role in the negotiations between Portugal and the Allies and the ceding of the bases by Salazar, which prevented their forced occupation. The espionage caused several diplomatic tensions, and the large number of German spies denounced by the British, operating on the islands under the watchful eye of the PVDE and Salazar, weakened the Portuguese-British alliance. Using primary source documents in the Ministério dos Negócios Estrangeiros (MNE) archives, this paper introduces the spies that operated on the islands, their missions and motives, organizations, and modus operandi. As a chess game, any move was careful thinking and the spies were valuable assets to control and use information that could lead to the occupation of the islands and, ultimately, change the tide of the war.Keywords: espionage, Azores, WWI, neutrality
Procedia PDF Downloads 663103 Controlled Growth of Charge Transfer Complex Nanowire by Physical Vapor Deposition Method Using Dielectrophoretic Force
Authors: Rabaya Basori, Arup K. Raychaudhuri
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In recent years, a variety of semiconductor nanowires (NWs) has been synthesized and used as basic building blocks for the development of electronic and optoelectronic nanodevices. Dielectrophoresis (DEP) has been widely investigated as a scalable technique to trap and manipulate polarizable objects. This includes biological cells, nanoparticles, DNA molecules, organic or inorganic NWs and proteins using electric field gradients. In this article, we have used DEP force to localize nanowire growth by physical vapor deposition (PVD) method as well as control of NW diameter on field assisted growth of the NWs of CuTCNQ (Cu-tetracyanoquinodimethane); a metal-organic charge transfer complex material which is well known of resistive switching. We report a versatile analysis platform, based on a set of nanogap electrodes, for the controlled growth of nanowire. Non-uniform electric field and dielectrophoretic force is created in between two metal electrodes, patterned by electron beam lithography process. Suspended CuTCNQ nanowires have been grown laterally between two electrodes in the vicinity of electric field and dielectric force by applying external bias. Growth and diameter dependence of the nanowires on external bias has been investigated in the framework of these two forces by COMSOL Multiphysics simulation. This report will help successful in-situ nanodevice fabrication with constrained number of NW and diameter without any post treatment.Keywords: nanowire, dielectrophoretic force, confined growth, controlled diameter, comsol multiphysics simulation
Procedia PDF Downloads 1923102 A Varicella Outbreak in a Highly Vaccinated School Population in Voluntary 2-Dose Era in Beijing, China
Authors: Chengbin Wang, Li Lu, Luodan Suo, Qinghai Wang, Fan Yang, Xu Wang, Mona Marin
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Background: Two-dose varicella vaccination has been recommended in Beijing since November 2012. We investigated a varicella outbreak in a highly vaccinated elementary school population to examine transmission patterns and risk factors for vaccine failure. Methods: A varicella case was defined as an acute generalized maculopapulovesicular rash without other apparent cause in a student attending the school from March 28 to May 17, 2015. Breakthrough varicella was defined as varicella >42 days after last vaccine dose. Vaccination information was collected from immunization records. Information on prior disease and clinical presentation was collected via survey of students’ parents. Results: Of the 1056 school students, 1028 (97.3%) reported no varicella history, of whom 364 (35.4%) had received 1-dose and 650 (63.2%) had received 2-dose varicella vaccine, for 98.6% school-wide vaccination coverage with ≥ 1 dose before the outbreak. A total of 20 cases were identified for an overall attack rate of 1.9%. The index case was in a 2-dose vaccinated student who was not isolated. The majority of cases were breakthrough (19/20, 95%) with attack rates of 7.1% (1/14), 1.6% (6/364) and 2.0% (13/650) among unvaccinated, 1-dose, and 2-dose students, respectively. Most cases had < 50 lesions (18/20, 90%). No difference was found between 1-dose and 2-dose breakthrough cases in disease severity or sociodemographic factors. Conclusion: Moderate 2-dose varicella vaccine coverage was insufficient to prevent a varicella outbreak. Two-dose breakthrough varicella is still contagious. High 2-dose varicella vaccine coverage and timely isolation of ill persons might be needed for varicella outbreak control in the 2-dose era.Keywords: varicella, outbreak, breakthrough varicella, vaccination
Procedia PDF Downloads 3353101 Evaluating a Peer-To-Peer Health Education Program in Public Housing Communities during the COVID-19 Pandemic
Authors: Jane Oliver, Angeline Ferdinand, Jessica Kaufman, Peta Edler, Nicole Allard, Margie Danchin, Katherine B. Gibney
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Background: The cohealth Health Concierge program operated in Melbourne, Australia, from July 2020 to 30 June 2022. The program was designed to provide place-based peer-to-peer COVID-19 education and support to culturally and linguistically diverse residents of high-rise public housing estates. During this time, the COVID-19 public health response changed frequently. We conducted a mixed-methods evaluation to determine the program’s impact on residents’ trust, engagement and communication with health services and public health activities. Methods: The RE-AIM model was used to assess program reach, effectiveness, adoption, implementation and maintenance and the evaluation was informed by a Project Reference Group including end-users. Data were collected between March and May 2022 in four estates where the program operated. We surveyed 301 residents, conducted qualitative interviews with 32 stakeholders and analyzed data from 20,901 forms reporting interactions between Health Concierges and residents collected from August 2021 to May 2022. These forms outlined the support provided by Health Concierges during each interaction. Results: Overall, the program was effective in guiding residents to testing and vaccination services and facilitating COVID-19 safe practices. Nearly two-thirds (191; 63.5%) of the 301 surveyed participants reported speaking with a Health Concierge in the previous six months, and some described having meaningful conversations with them. Despite this, many of the interactions residents described having with Health Concierges were superficial. When considering surveyed participants’ responses to the adapted Public Health Disaster Trust Scale, the mean score across all estates was 2.3 (or slightly more than ‘somewhat confident’) in public health authorities’ ability to respond to a localized infectious disease outbreak. While the program was valued during the rapidly changing public health response, many felt it had failed to evolve in the ‘living with COVID’ phase. Some residents expressed frustration with Health Concierges’ having perceived inactive, passive roles - although other residents felt Health Concierges were helpful and appreciated them. A perception that the true impact of Health Concierges’ work was underrecognized was widely voiced by health staff. All 20,901 Interaction Forms identified COVID-19-related supports provided to residents; almost all included provision of facemasks and/or hand sanitiser and 78% identified additional supports that were also provided, most frequently provision of other health information. Conclusions: The program disseminated up-to-date information to a diverse population within a rapidly changing public health setting. Health Concierges were able promote COVID-19-safe behaviours, including vaccine uptake, and link residents with support services. We recommend the program be revised and continued. New programs that draw on the Health Concierge model may be valuable in supporting future pandemic responses and should be considered in preparedness planning.Keywords: community health, COVID-19 pandemic, infectious diseases, public health, community health workers
Procedia PDF Downloads 1003100 Exploring Type V Hydrogen Storage Tanks: Shape Analysis and Material Evaluation for Enhanced Safety and Efficiency Focusing on Drop Test Performance
Authors: Mariam Jaber, Abdullah Yahya, Mohammad Alkhedher
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The shift toward sustainable energy solutions increasingly focuses on hydrogen, recognized for its potential as a clean energy carrier. Despite its benefits, hydrogen storage poses significant challenges, primarily due to its low energy density and high volatility. Among the various solutions, pressure vessels designed for hydrogen storage range from Type I to Type V, each tailored for specific needs and benefits. Notably, Type V vessels, with their all-composite, liner-less design, significantly reduce weight and costs while optimizing space and decreasing maintenance demands. This study focuses on optimizing Type V hydrogen storage tanks by examining how different shapes affect performance in drop tests—a crucial aspect of achieving ISO 15869 certification. This certification ensures that if a tank is dropped, it will fail in a controlled manner, ideally by leaking before bursting. While cylindrical vessels are predominant in mobile applications due to their manufacturability and efficient use of space, spherical vessels offer superior stress distribution and require significantly less material thickness for the same pressure tolerance, making them advantageous for high-pressure scenarios. However, spherical tanks are less efficient in terms of packing and more complex to manufacture. Additionally, this study introduces toroidal vessels to assess their performance relative to the more traditional shapes, noting that the toroidal shape offers a more space-efficient option. The research evaluates how different shapes—spherical, cylindrical, and toroidal—affect drop test outcomes when combined with various composite materials and layup configurations. The ultimate goal is to identify optimal vessel geometries that enhance the safety and efficiency of hydrogen storage systems. For our materials, we selected high-performance composites such as Carbon T-700/Epoxy, Kevlar/Epoxy, E-Glass Fiber/Epoxy, and Basalt/Epoxy, configured in various orientations like [0,90]s, [45,-45]s, and [54,-54]. Our tests involved dropping tanks from different angles—horizontal, vertical, and 45 degrees—with an internal pressure of 35 MPa to replicate real-world scenarios as closely as possible. We used finite element analysis and first-order shear deformation theory, conducting tests with the Abaqus Explicit Dynamics software, which is ideal for handling the quick, intense stresses of an impact. The results from these simulations will provide valuable insights into how different designs and materials can enhance the durability and safety of hydrogen storage tanks. Our findings aim to guide future designs, making them more effective at withstanding impacts and safer overall. Ultimately, this research will contribute to the broader field of lightweight composite materials and polymers, advancing more innovative and practical approaches to hydrogen storage. By refining how we design these tanks, we are moving toward more reliable and economically feasible hydrogen storage solutions, further emphasizing hydrogen's role in the landscape of sustainable energy carriers.Keywords: hydrogen storage, drop test, composite materials, type V tanks, finite element analysis
Procedia PDF Downloads 463099 New Employee on-Boarding Program: Effective Tool for Reducing the Prevalence of Workplace Injuries/Accidents
Authors: U. Ugochukwu, J. Lee, P. Conley
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According to a recent survey by the UT Southwestern Workplace Safety Committee, the three most common on-the-job injuries reported by workers at the medical center are musculoskeletal injuries, slip-and-fall injuries and repetitive motion injuries. Last year alone, of the 650 documented workplace injuries and accidents, 45% were seen in employees in their first-two years of employment. UT Southwestern New Employee On-Boarding program was created and modeled to follows OSHA’s model that consist of: determining if training is needed, identifying training needs, identifying goals and objectives, developing learning activities, conducting the training, evaluating program effectiveness, and improving the program. The hospital’s management best practices were recreated to limit and control workplace injuries and accidents. Regular trainings and workshops on workplace safety and compliance were initiated for new employees. Various computer workstations were evaluated and recommendations were made to reduce musculoskeletal disorders. Post exposure protocols and workers protection programs were remodeled for infectious agents and chemicals used in the hospital, and medical surveillance programs were updated, for every emerging threat, to ensure they are in compliance with the US policy, regulatory and standard setting organizations. If ignorance of specific job hazards and of proper work practices is to blame for this higher injury rate, then training will help to provide a solution. Use of this program in training activities is just one of many ways UT Southwestern complied with the OSHA standards that relate to training while enhancing the safety and health of their employees.Keywords: ergonomics, hazard, on-boarding, surveillance, workplace
Procedia PDF Downloads 3303098 Evaluation of Alternative Approaches for Additional Damping in Dynamic Calculations of Railway Bridges under High-Speed Traffic
Authors: Lara Bettinelli, Bernhard Glatz, Josef Fink
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Planning engineers and researchers use various calculation models with different levels of complexity, calculation efficiency and accuracy in dynamic calculations of railway bridges under high-speed traffic. When choosing a vehicle model to depict the dynamic loading on the bridge structure caused by passing high-speed trains, different goals are pursued: On the one hand, the selected vehicle models should allow the calculation of a bridge’s vibrations as realistic as possible. On the other hand, the computational efficiency and manageability of the models should be preferably high to enable a wide range of applications. The commonly adopted and straightforward vehicle model is the moving load model (MLM), which simplifies the train to a sequence of static axle loads moving at a constant speed over the structure. However, the MLM can significantly overestimate the structure vibrations, especially when resonance events occur. More complex vehicle models, which depict the train as a system of oscillating and coupled masses, can reproduce the interaction dynamics between the vehicle and the bridge superstructure to some extent and enable the calculation of more realistic bridge accelerations. At the same time, such multi-body models require significantly greater processing capacities and precise knowledge of various vehicle properties. The European standards allow for applying the so-called additional damping method when simple load models, such as the MLM, are used in dynamic calculations. An additional damping factor depending on the bridge span, which should take into account the vibration-reducing benefits of the vehicle-bridge interaction, is assigned to the supporting structure in the calculations. However, numerous studies show that when the current standard specifications are applied, the calculation results for the bridge accelerations are in many cases still too high compared to the measured bridge accelerations, while in other cases, they are not on the safe side. A proposal to calculate the additional damping based on extensive dynamic calculations for a parametric field of simply supported bridges with a ballasted track was developed to address this issue. In this contribution, several different approaches to determine the additional damping of the supporting structure considering the vehicle-bridge interaction when using the MLM are compared with one another. Besides the standard specifications, this includes the approach mentioned above and two additional recently published alternative formulations derived from analytical approaches. For a bridge catalogue of 65 existing bridges in Austria in steel, concrete or composite construction, calculations are carried out with the MLM for two different high-speed trains and the different approaches for additional damping. The results are compared with the calculation results obtained by applying a more sophisticated multi-body model of the trains used. The evaluation and comparison of the results allow assessing the benefits of different calculation concepts for the additional damping regarding their accuracy and possible applications. The evaluation shows that by applying one of the recently published redesigned additional damping methods, the calculation results can reflect the influence of the vehicle-bridge interaction on the design-relevant structural accelerations considerably more reliable than by using normative specifications.Keywords: Additional Damping Method, Bridge Dynamics, High-Speed Railway Traffic, Vehicle-Bridge-Interaction
Procedia PDF Downloads 1613097 Genomic and Proteomic Variation in Glycine Max Genotypes towards Salinity
Authors: Faheema Khan
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In order to investigate the influence of genetic background on salt tolerance in Soybean (Glycine max) ten soybean genotypes released/notified in India were selected. (Pusa-20, Pusa-40, Pusa-37, Pusa-16, Pusa-24, Pusa-22, BRAGG, PK-416, PK-1042, and DS-9712). The 10-day-old seedlings were subjected to 0, 25, 50, 75, 100, 125, and 150 mM NaCl for 15 days. Plant growth, leaf osmotic adjustment, and RAPD analysis were studied. In comparison to control plants, the plant growth in all genotypes was decreased by salt stress, respectively. Salt stress decreased leaf osmotic potential in all genotypes however the maximum reduction was observed in genotype Pusa-24 followed by PK-416 and Pusa-20. The difference in osmotic adjustment between all the genotypes was correlated with the concentrations of ion examined such as Na+ and the leaf proline concentration. These results suggest that the genotypic variation for salt tolerance can be partially accounted for by plant physiological measures. The genetic polymorphisms between soybean genotypes differing in response to salt stress were characterized using 25 RAPD primers. These primers generated a total of 1640 amplification products, among which 1615 were found to be polymorphic. A very high degree of polymorphism (98.30%) was observed. UPGMA cluster analysis of genetic similarity indices grouped all the genotypes into two major clusters. Intra-clustering within the two clusters precisely grouped the 10 genotypes in sub-cluster as expected from their physiological findings. Our results show that RAPD technique is a sensitive, precise and efficient tool for genomic analysis in soybean genotypes.Keywords: glycine max, NaCl, RAPD, proteomics
Procedia PDF Downloads 5853096 An Effect of Organic Supplements on Stimulating Growth of Dendrobium Protocorms and Seedlings
Authors: Sunthari Tharapan, Chockpisit Thepsithar, Kullanart Obsuwan
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This study was aimed to investigate the effect of various organic supplements on growth and development of Dendrobium discolor’s protocorms and seedlings growth of Dendrobium Judy Rutz. Protocorms of Dendrobium discolor with 2.0 cm. in diameter and seedlings of Dendrobium Judy Rutz at the same size (0.5 cm. height) were sub-cultured on Hyponex medium supplemented with cow milk (CM), soy milk (SM), potato extract (PE) and peptone (P) for 2 months. The protocorms were developed to seedlings in all treatments after cultured for 2 months. However, the best results were found on Hyponex medium supplemented with P was the best in which the maximum fresh and dry weight and maximum shoot height were obtained in this treatment statistically different (p ≤ 0.05) to other treatments. Moreover, Hyponex medium supplemented with P also stimulated the maximum mean number of 5.7 shoots per explant which also showed statistically different (p ≤ 0.05) when compared to other treatments. The results of growth of Dendrobium Judy Rutz seedlings indicated the medium supplemented with 100 mL/L PE enhanced the maximum fresh and dry weigh per explants with significantly different (p ≤ 0.05) in fresh weight from other treatments including the control medium without any organic supplementation. However, the dry weight was not significantly different (p ≤ 0.05) from medium supplemented with SM and P. There was multiple shoots induction in all media with or without organic supplementation ranging from 2.6 to 3 shoots per explants. The maximum shoot height was also obtained in the seedlings cultured on medium supplemented with PE while the longest root length was found in medium supplemented with SM.Keywords: fresh weight, in vitro propagation, orchid, plant height
Procedia PDF Downloads 3653095 Quality of Life and Willingness to Take Treatment and the Importance of the Disease in the Lives of Patients with Eating Disorders
Authors: Marzena Trojanczyk, Mariusz Jaworski, Ewa Dmoch Gajzlerska
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Purpose: The purpose of this paper is to assess the relationship between the level of quality of life and willingness to take treatment in patients with eating disorders as anorexia, bulimia and compulsive bingeing. Material and methods: The subjects consisted of 99 women with eating disorders: anorexia, n = 33; bulimia, n = 35; compulsive overeating, n = 31 and 35 women in the control group. The study used an original questionnaire to assess the overall quality of life, as well as selected areas of the physical, mental, social and spiritual satisfaction. The subjects were also asked about the level of motivation for treatment, and the importance of the disease in the lives of patients. Statistical analyses were performed using the statistical program SPSS 18.0. Results: Women with eating disorders in particular groups did not differ with respect to each other in the aspect of overall quality of life, satisfaction with the development of the spiritual, social functioning and mental health. The severity level of the disease in the lives of patients showed a negative correlation with social functioning in women with anorexia nervosa. In the case of patients with compulsive bingeing a positive relationship between the level of importance of the disease and the satisfaction of spiritual development is reported. Conclusions: Concerning the inferior quality of life, there is no relationship between a willingness to take treatment and the importance of the disease in the lives of patients with anorexia, bulimia and compulsive bingeing.Keywords: anorexia, bulimia, compulsive overeating, quality of life
Procedia PDF Downloads 3903094 Development of Stability Indicating Method and Characterization of Degradation Impurity of Nirmaltrelvir in Its Self-Emulsifying Drug Delivery System
Authors: Ravi Patel, Ravisinh Solanki, Dignesh Khunt
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A stability-indicating reverse phase high performance liquid chromatography (RP-HPLC) method was developed and validated for estimating Nirmatrelvir in its self-emulsifying drug delivery system (SEDDS). The separation of Nirmatrelvir and its degradation products was accomplished by employing an Agilent Zorbax Eclipse plus C18 (250 mm x 4.6 mm, 5 µm) column, through which the mobile phase 5 mM phosphate buffer (pH 4.0) as mobile phase A and Acetonitrile as mobile phase B in a ratio of (40:60 % v/v) was pumped at a flow rate of 1.0 mL/min, through the HPLC system. Chromatographic separation and elution were monitored by a photo-diode array detector at 210 nm. Stress studies have been employed to evaluate this method's ability to indicate stability. Nirmatrelvir was exposed to several stress conditions, such as acid, alkali, oxidative, photolytic, and thermal degradations. Significant degradation was observed during acid and alkali hydrolysis, and the resulting degradation product was successfully separated from the Nirmatrelvir peak, preventing any interference. Furthermore, the primary degradant produced under alkali degradation conditions was identified using UPLC-ESI-TQ-MS/MS. The method was validated in accordance with the International Council on Harmonization (ICH) and found to be selective, precise, accurate, linear, and robust. The apparent permeability of Nirmatrelvir SEDDS was 4.20 ± 0.21×10-6 cm/sec, and the average proportion of free drug recovered was 0.5%. The method developed in this study was feasible and accurate for routine quality control evaluation of Nirmatrelvir SEDDS.Keywords: Nirmatrelvir, SEDDS, degradation study, HPLC, LC-MS/MS
Procedia PDF Downloads 183093 Non-Destructive Testing of Selective Laser Melting Products
Authors: Luca Collini, Michele Antolotti, Diego Schiavi
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At present, complex geometries within production time shrinkage, rapidly increasing demand, and high-quality standard requirement make the non-destructive (ND) control of additively manufactured components indispensable means. On the other hand, a technology gap and the lack of standards regulating the methods and the acceptance criteria indicate the NDT of these components a stimulating field to be still fully explored. Up to date, penetrant testing, acoustic wave, tomography, radiography, and semi-automated ultrasound methods have been tested on metal powder based products so far. External defects, distortion, surface porosity, roughness, texture, internal porosity, and inclusions are the typical defects in the focus of testing. Detection of density and layers compactness are also been tried on stainless steels by the ultrasonic scattering method. In this work, the authors want to present and discuss the radiographic and the ultrasound ND testing on additively manufactured Ti₆Al₄V and inconel parts obtained by the selective laser melting (SLM) technology. In order to test the possibilities given by the radiographic method, both X-Rays and γ-Rays are tried on a set of specifically designed specimens realized by the SLM. The specimens contain a family of defectology, which represent the most commonly found, as cracks and lack of fusion. The tests are also applied to real parts of various complexity and thickness. A set of practical indications and of acceptance criteria is finally drawn.Keywords: non-destructive testing, selective laser melting, radiography, UT method
Procedia PDF Downloads 1473092 Effect of Poultry Manure and Nitrogen, Phosphorus, and Potassium (15:15:15) Soil Amendment on Growth and Yield of Carrot (Daucus carota)
Authors: Benjamin Osae Agyei, Hypolite Bayor
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This present experiment was carried out during the 2012 cropping season, at the Farming for the Future Experimental Field of the University for Development Studies, Nyankpala Campus in the Northern Region of Ghana. The objective of the experiment was to determine the carrot growth and yield responses to poultry manure and N.P.K (15:15:15). Six treatments (Control (no amendment), 20 t/ha poultry manure (PM), 40 t/ha PM, 70 t/ha PM, 35 t/ha PM + 0.11t/ha N.P.K and 0.23 t/ha N.P.K) with three replications for each were laid in a Randomized Complete Block Design (RCBD). Data were collected on plant height, number of leaves per plant, canopy spread, root diameter, root weight, and root length. Microsoft Excel and Genstat Statistical Package (9th edition) were used for the data analysis. The treatment means were compared by using Least Significant Difference at 10%. Generally, the results showed that there were no significant differences (P>0.1) among the treatments with respect to number of leaves per plant, root diameter, root weight, and root length. However, significant differences occurred among plant heights and canopy spreads. Plant height treated with 40 t/ha PM at the fourth week after planting and canopy spread at eight weeks after planting and ten weeks after planting by 70 t/ha PM and 20 t/ha PM respectively showed significant difference (P<0.1). The study recommended that any of the amended treatments can be applied at their recommended rates to plots for carrot production, since there were no significant differences among the treatments.Keywords: poultry manure, N.P.K., soil amendment, growth, yield, carrot
Procedia PDF Downloads 4713091 The Comparison between Resistance and Aerobic Exercise Training on Metabolic Syndrome Components in Overweight Sedentary Female
Authors: Marzieh Sayyad, Mohsen Salesi
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Metabolic syndrome (MetS), a collection of cardiometabolic risk factors, is linked to the development of cardiovascular disease (CVD) and diabetes. The prevalence of MetS is on the rise with more women affected than men. The goal of this study was to compare the effects of resistance and aerobic exercise training on metabolic syndrome components in non-athlete, middle-aged woman. 51 non-athlete overweight female participated voluntarily in this study. Participants were divided randomly into three groups including resistance, aerobic and control group (number of each group 17). 24 hours before the beginning of training program, the blood sample was taken in fasting state. The two training groups participated in sport activities for eight weeks, three times a week duration 60-90 minutes. Two days following the end of the 8th week, all the measurements were performed similar to the pretest phase. The data was analyzed using one-way analysis of variance. The results showed that aerobic exercise training significantly decreased weight (p=.05), triglyceride (p<0.01) and systolic blood pressure (p<0.02) and HDL-c (p<0.01) was significantly increased. Also in resistance exercise training group TG decreased significantly (p<0.01) and HDL-c (p<0.05) was significantly increased. This study demonstrated that a regular physical activity program improved several metabolic and physiological parameters in healthy, previously sedentary subjects with the metabolic syndrome. In conclusion, it seems that this type of training can be efficient, safe and inexpensive way in order to reduce and prevent metabolic syndrome.Keywords: aerobic exercise, metabolic syndrome, overweight sedentary female, resistance exercise
Procedia PDF Downloads 3053090 Influence of Sodium Lauryl Ether Sulfate and Curing Temperature on Behaviors of Lightweight Kaolinite-Based Geopolymer
Authors: W. Sornlar, S. Supothina, A. Wannagon
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Lightweight geopolymer can be prepared by using some foaming agents, such as metal powders or hydrogen peroxide; however, it is difficult to control the generated cell size due to the high reactivity of the system. This study aims to investigate the influence of Sodium Lauryl Ether Sulfate (SLES) foam addition and curing temperature on the physical, mechanical, thermal, and microstructure behaviors of the lightweight kaolinite-based geopolymer. To provide porous structure, the geopolymer paste was mixed with 0-15 wt% of SLES foam before casting into the mold. Testing and characterizations were carried out after 28 days. The results showed that SLES foam generated the regular and spherical macropores, which were well distributed in the geopolymer samples. The total porosity increased as SLES foam increased, similarly as the apparent porosity and water absorption. On the other hand, the bulk density and mechanical strength decreased as SLES foam increased. Curing temperature was studied simultaneously due to it strongly affects the mechanical strength of geopolymer. In this study, rising of curing temperature from 27 to 50°C (at 75% relative humidity) improved the compressive strength of samples but deteriorated after curing at 60°C. Among them, the composition of 15 wt% SLES foam (NF15) presented the highest porosity (70.51-72.89%), the lowest density (0.68-0.73 g/cm³), and very low thermal conductivity (0.172-0.197 W/mK). It had the proper compressive strength of 4.21-4.74 MPa that can be applied for the thermal insulation.Keywords: lightweight, kaolinite-based geopolymer, curing temperature, foaming agent, thermal conductivity
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