Search results for: dose intensity
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 3156

Search results for: dose intensity

2076 Cardioprotective Effect of the Leaf Extract of Andrographis Paniculata in Isoproterenol-Induced Myocardial Infarction

Authors: Emmanuel Ikechuckwu Onwubuya, Afees Adebayo Oladejo

Abstract:

Background: The use of medicinal plants in the treatment of chronic diseases especially myocardial infarction, is gaining wide acceptance globally. Andrographis paniculata (Acanthaceae) is a medicinal plant commonly known as the king of bitters in Nigeria and has been acclaimed for several therapeutic activities. Materials and methods: This study investigated the cardio-protective effect of the leaf extract of A. paniculata in isoproterenol-induced myocardial infarction. Fresh green leaves of A paniculata were harvested from the Faculty of Agriculture farmland, Nnamdi Azikiwe University, Awka, Nigeria. Identification and authentication of the plant were carried out at the Department of Botany, Nnamdi Azikiwe University and a voucher specimen was deposited at the herbarium. The plant material was then shredded, air-dried under shade and pulverized. The fine powders obtained were weighed and extraction was done via a solvent combination of water and ethanol (3:7) for 72 hr via maceration. The filtrate gotten was evaporated to dryness to obtain the ethanol extract, which was used for further bioassay study. The bioactive constituents of the plant extract were quantitatively analyzed by Gas chromatography-mass spectrometry (GC-MS). The animals were administered the extract of A. paniculata orally for seven days at a divided dose of 100 mg/kg, 200 mg/kg and 400 mg/kg body weights. On the eighth day, myocardial infarction was induced through subcutaneous administration of isoproterenol at a dose of 150 mg/kg/day diluted in 2 ml of saline on two consecutive days. Subsequently, the blood pressures were monitored and blood was collected for bioassay studies. Results: The results of the study showed that the leaf extract of A. paniculata was rich in Dodecanoic acid (8.261%), 4-Dibenzofuranamine (6.03%), Cyclotrisiloxane (4.679 %). The findings also showed a significant decrease (p>0.05) in the Mean arterial blood pressure, heart rate, aspartate transaminase, alanine transaminase, creatinine kinase and lactate dehydrogenase activities of the treatment group compared with the untreated control group while the antioxidant (superoxide dismutase, catalase and glutathione) activities were significantly increased in the treatment group, compared with the untreated control group. Conclusion: The findings of this work have shown that the leaf of A. paniculata was rich in bioactive compounds, which could be synthesized to produce plant-based products to fight cardiovascular diseases, especially myocardial infarction.

Keywords: cardiovascular disease, myocardial infarction, medicinal plant, andrographis paniculata, isoproterenol

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2075 Adsorption of a Pharmaceutical Pollutant on Activated Carbon of Orange Peels

Authors: Faroudja Mohellebi, Fayrouz Khalida Kies, Moncef Rezzik El Marhoun, Feriel Yahiat

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The purpose of this study is to valorize an agro-food waste (orange peels) by its use as an adsorbent in the treatment of water loaded with pharmaceutical micropollutant present in aquatic environments, oxytetracycline. The tests, carried out in batch mode, made it possible to study the influence on the sorptive capacity of calcined orange peels of several parameters: the contact time, the initial concentration of oxytetracycline, the adsorbent dose, and the initial pH of the solution. The pseudo-second-order model is best adapted to represent the adsorption kinetics. The Langmuir model describes the adsorption isotherm of oxytetracycline. The adsorption is favored in a basic environment.

Keywords: adsorption, emerging pollutants, oxytetracycline, water treatment

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2074 Osteochondroma of Clivus: An Unusual Cause of Headache

Authors: Muhammad Faisal Khilji, Rana Shoaib Hamid, Asim Qureshi

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A fifty years old female presented in the emergency department of a tertiary care hospital with complaints of migraine type headache for the last few months. Her last episode of headache was severe, increasing in intensity, associated with nausea but no fever, lasting more than 24 hours and not resolving with analgesics. On examination there was no neurological deficit. CT scan of brain showed a large Pedunculated, non-expansible, non-aggressive bony lesion in the clivus with its sharp fragment impinging into the pons. Findings were further confirmed with MRI brain. Trans-sphenoidal excision biopsy was done and histopathology proved the lesion to be osteochondroma of clivus.

Keywords: osteochondroma, clivus, headache, CT scan

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2073 Improvement of Autism Diagnostic Observation Schedule Scores after Comprehensive Intensive Early Interventions in a Clinical Setting

Authors: Nils Haglund, Svenolof Dahlgren, Maria Rastam, Peik Gustafsson, Karin Kalien

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In Sweden, like in most developed countries, there is a substantial increase of children diagnosed with autism and other conditions within the autism spectrum (ASD). The rapid increase of ASD rates stresses the importance of developing care programs to provide support and comprehensive interventions for affected families. The current observational study was conducted in order to evaluate an ongoing Comprehensive Intensive Early Intervention (CIEI) program for children with autism in southern Sweden. The change in autism symptoms among children participating in CIEI (intervention group, n=67) was compared with children who received traditional habilitation services only (comparison group, n=27). Children of parents who accepted the offered CIEI-program, constituted the intervention group, whereas children, whose parents (for some reason) were not interested in the offered CIEI-program, constituted the comparison group. The CIEI-program was individualized to each child by experienced applied behavior analysis (ABA) specialists with different backgrounds as psychologists, speech pathologists or special education teachers, in cooperation with parents and preschool staff. Due to the individualization, the intervention could vary in intensity and techniques. The intensity was calculated to 15-25 hours each week at home and the preschool altogether. Each child was assigned one 'trainer', who was often employed as a preschool teacher but could have another educational background. An agreement between supervisor- parents and preschool staff was reached to confirm the intensity and content of the CIEI- program over an approximately two-year intervention period. Symptom changes were measured as evaluation-ADOS-2-scores, total- and severity-scores, minus the corresponding baseline-scores, divided by the time between baseline and evaluation. The difference between the study-groups regarding change of ADOS-2-scores was estimated using ANCOVA. In the current study, children in the CIEI-group improved their ADOS-2-total scores between baseline and evaluation (-0.8 scores per year; 95%CI: -1.2 to -0.4), whereas no such improvement was detected in the comparison group (+0.1 scores per year; 95%CI: -0.7 to +0.9). The change difference (change in the CIEI-group vs. change in the comparison group) was statistically significant, both crude and after adjusting for possible confounders (-1.1; 95%CI -1.9 to -0.4). Children in the CIEI-group also significantly improved their ADOS-calibrated severity scores, but not significantly differently so from the comparison group. The results from the current study indicate that the CIEI program significantly improves social and communicative skills among children with autism and that children with developmental delay could benefit to a similar degree as other children. The results support earlier studies reporting on the improvement of autism symptoms after early intensive interventions. The results from observational studies are difficult to interpret, but it is nevertheless of uttermost importance to evaluate costly autism intervention programs. Such results may be of immediate importance to healthcare organizations when allocating the already strained resources to different patient groups. Albeit the obvious limitation of the current naturalistic study, the results support previous positive studies and indicate that children with autism benefit from participating in early comprehensive, intensive programs and that investments in these programs may be highly justifiable.

Keywords: autism symptoms, ADOS-scores, evaluation, intervention program

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2072 A Case Report: The Role of Gut Directed Hypnotherapy in Resolution of Irritable Bowel Syndrome in a Medication Refractory Pediatric Male Patient

Authors: Alok Bapatla, Pamela Lutting, Mariastella Serrano

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Background: Irritable Bowel Syndrome (IBS) is a functional gastrointestinal disorder characterized by abdominal pain associated with altered bowel habits in the absence of an underlying organic cause. Although the exact etiology of IBS is not fully understood, one of the leading theories postulates a pathology within the Brain-Gut Axis that leads to an overall increase in gastrointestinal sensitivity and pejorative changes in gastrointestinal motility. Research and clinical practice have shown that Gut Directed Hypnotherapy (GDH) has a beneficial clinical role in improving Mind-Gut control and thereby comorbid conditions such as anxiety, abdominal pain, constipation, and diarrhea. Aims: This study presents a 17-year old male with underlying anxiety and a one-year history of IBS-Constipation Predominant Subtype (IBS-C), who has demonstrated impressive improvement of symptoms following GDH treatment following refractory trials with medications including bisacodyl, senna, docusate, magnesium citrate, lubiprostone, linaclotide. Method: The patient was referred to a licensed clinical psychologist specializing in clinical hypnosis and cognitive-behavioral therapy (CBT), who implemented “The Standardized Hypnosis Protocol for IBS” developed by Dr. Olafur S. Palsson, Psy.D at the University of North Carolina at Chapel Hill. The hypnotherapy protocol consisted of a total of seven weekly 45-minute sessions supplemented with a 20-minute audio recording to be listened to once daily. Outcome variables included the GAD-7, PHQ-9 and DCI-2, as well as self-ratings (ranging 0-10) for pain (intensity and frequency), emotional distress about IBS symptoms, and overall emotional distress. All variables were measured at intake prior to administration of the hypnosis protocol and at the conclusion of the hypnosis treatment. A retrospective IBS Questionnaire (IBS Severity Scoring System) was also completed at the conclusion of the GDH treatment for pre-and post-test ratings of clinical symptoms. Results: The patient showed improvement in all outcome variables and self-ratings, including abdominal pain intensity, frequency of abdominal pain episodes, emotional distress relating to gut issues, depression, and anxiety. The IBS Questionnaire showed a significant improvement from a severity score of 400 (defined as severe) prior to GDH intervention compared to 55 (defined as complete resolution) at four months after the last session. IBS Questionnaire subset questions that showed a significant score improvement included abdominal pain intensity, days of pain experienced per 10 days, satisfaction with bowel habits, and overall interference of life affected by IBS symptoms. Conclusion: This case supports the existing research literature that GDH has a significantly beneficial role in improving symptoms in patients with IBS. Emphasis is placed on the numerical results of the IBS Questionnaire scoring, which reflects a patient who initially suffered from severe IBS with failed response to multiple medications, who subsequently showed full and sustained resolution

Keywords: pediatrics, constipation, irritable bowel syndrome, hypnotherapy, gut-directed hypnosis

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2071 Assessing the Effect of Urban Growth on Land Surface Temperature: A Case Study of Conakry Guinea

Authors: Arafan Traore, Teiji Watanabe

Abstract:

Conakry, the capital city of the Republic of Guinea, has experienced a rapid urban expansion and population increased in the last two decades, which has resulted in remarkable local weather and climate change, raise energy demand and pollution and treating social, economic and environmental development. In this study, the spatiotemporal variation of the land surface temperature (LST) is retrieved to characterize the effect of urban growth on the thermal environment and quantify its relationship with biophysical indices, a normalized difference vegetation index (NDVI) and a normalized difference built up Index (NDBI). Landsat data TM and OLI/TIRS acquired respectively in 1986, 2000 and 2016 were used for LST retrieval and Land use/cover change analysis. A quantitative analysis based on the integration of a remote sensing and a geography information system (GIS) has revealed an important increased in the LST pattern in the average from 25.21°C in 1986 to 27.06°C in 2000 and 29.34°C in 2016, which was quite eminent with an average gain in surface temperature of 4.13°C over 30 years study period. Additionally, an analysis using a Pearson correlation (r) between (LST) and the biophysical indices, normalized difference vegetation index (NDVI) and a normalized difference built-up Index (NDBI) has revealed a negative relationship between LST and NDVI and a strong positive relationship between LST and NDBI. Which implies that an increase in the NDVI value can reduce the LST intensity; conversely increase in NDBI value may strengthen LST intensity in the study area. Although Landsat data were found efficient in assessing the thermal environment in Conakry, however, the method needs to be refined with in situ measurements of LST in the future studies. The results of this study may assist urban planners, scientists and policies makers concerned about climate variability to make decisions that will enhance sustainable environmental practices in Conakry.

Keywords: Conakry, land surface temperature, urban heat island, geography information system, remote sensing, land use/cover change

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2070 PbLi Activation Due to Corrosion Products in WCLL BB (EU-DEMO) and Its Impact on Reactor Design and Recycling

Authors: Nicole Virgili, Marco Utili

Abstract:

The design of the Breeding Blanket in Tokamak fusion energy systems has to guarantee sufficient availability in addition to its functions, that are, tritium breeding self-sufficiency, power extraction and shielding (the magnets and the VV). All these function in the presence of extremely harsh operating conditions in terms of heat flux and neutron dose as well as chemical environment of the coolant and breeder that challenge structural materials (structural resistance and corrosion resistance). The movement and activation of fluids from the BB to the Ex-vessel components in a fusion power plant have an important radiological consideration because flowing material can carry radioactivity to safety-critical areas. This includes gamma-ray emission from activated fluid and activated corrosion products, and secondary activation resulting from neutron emission, with implication for the safety of maintenance personnel and damage to electrical and electronic equipment. In addition to the PbLi breeder activation, it is important to evaluate the contribution due to the activated corrosion products (ACPs) dissolved in the lead-lithium eutectic alloy, at different concentration levels. Therefore, the purpose of the study project is to evaluate the PbLi activity utilizing the FISPACT II inventory code. Emphasis is given on how the design of the EU-DEMO WCLL, and potential recycling of the breeder material will be impacted by the activation of PbLi and the associated active corrosion products (ACPs). For this scope the following Computational Tools, Data and Geometry have been considered: • Neutron source: EU-DEMO neutron flux < 1014/cm2/s • Neutron flux distribution in equatorial breeding blanket module (BBM) #13 in the WCLL BB outboard central zone, which is the most activated zone, with the aim to introduce a conservative component utilizing MNCP6. • The recommended geometry model: 2017 EU DEMO CAD model. • Blanket Module Material Specifications (Composition) • Activation calculations for different ACP concentration levels in the PbLi breeder, with a given chemistry in stationary equilibrium conditions, using FISPACT II code. Results suggest that there should be a waiting time of about 10 years from the shut-down (SD) to be able to safely manipulate the PbLi for recycling operations with simple shielding requirements. The dose rate is mainly given by the PbLi and the ACP concentration (x1 or x 100) does not shift the result. In conclusion, the results show that there is no impact on PbLi activation due to ACPs levels.

Keywords: activation, corrosion products, recycling, WCLL BB., PbLi

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2069 Behavioral Study Circumferential and Longitudinal Cracks in a Steel Pipeline X65 and Repair Patch

Authors: Sadok Aboubakr

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The mechanical behavior of cracks from several manufacturing defect in an oil pipeline, is characterized by the fact that defects'm taking several forms: circumferential, longitudinal and inclined crack that evolve over time. Increased lifetime of the constructions and in particular cylindrical tubes under internal pressure requires knowledge improving these defects during loading. From this study we simulated various forms of cracking and also their pipeline repair patch.

Keywords: stress intensity factor, pressure, Young's modulus, Poisson's ratio, Shear modulus, Longueur du pipeline, the angle of crack, crack length

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2068 Modeling SET Effect on Charge Pump Phase Locked Loop

Authors: Varsha Prasad, S. Sandya

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Cosmic Ray effects in microelectronics such as single event effect (SET) and total dose ionization (TID) have been of major concern in space electronics since 1970. Advanced CMOS technologies have demonstrated reduced sensitivity to TID effect. However, charge pump Phase Locked Loop is very much vulnerable to single event transient effect. This paper presents an SET analysis model, where the SET is modeled as a double exponential pulse. The time domain analysis reveals that the settling time of the voltage controlled oscillator (VCO) depends on the SET pulse strength, setting the time constant and the damping factor. The analysis of the proposed SET analysis model is confirmed by the simulation results.

Keywords: charge pump, phase locked loop, SET, VCO

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2067 A Combination of Mesenchymal Stem Cells and Low-Intensity Ultrasound for Knee Meniscus Regeneration: A Preliminary Study

Authors: Mohammad Nasb, Muhammad Rehan, Chen Hong

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Background Meniscus defects critically alter knee function and lead to degenerative changes. Regenerative medicine applications including stem cell transplantation have showed a promising efficacy in finding alternatives to overcome traditional treatment limitations. However, stem cell therapy remains limited due to the substantially reduced viability and inhibitory microenvironment. Since tissue growth and repair are under the control of biochemical and mechanical signals, several approaches have recently been investigated (e.g., low intensity pulsed ultrasound [LIPUS]) to promote the regeneration process. This study employed LIPUS to improve growth and osteogenic differentiation of mesenchymal stem cells derived from human embryonic stem cells to improve the regeneration of meniscus tissue. Methodology: The Mesenchymal stromal cells (MSCs) were transplanted into the epicenter of the injured meniscus in rabbits, which were randomized into two main groups: a treatment group (n=32 New Zealand rabbits) including 4 subgroups of 8 rabbits in each subgroup (LIPUS treatment, MSC treatment, LIPUS with MSC and control), and a second group (n=9) to track implanted cells and their progeny using green fluorescence protein (GFP). GFP consists of the MSC and LIPUS-MSC combination subgroups. Rabbits were then subjected to histological, immunohistochemistry, and MRI assessment. Results: The quantity of the newly regenerated tissue in the combination treatment group that had Ultrasound irradiation after mesenchymal stem cells were better at all end points. Likewise, Tissue quality scores were also greater in knees treated with both approaches compared with controls and single treatment at all end points, achieving significance at twelve and twenty-four weeks [p < 0.05], and [p = 0.008] at twelve weeks. Differentiation into type-I and II collagen-expressing cells were higher in the combination group at up to twenty-four weeks. Conclusions: the combination of mesenchymal stem cells and LIPUS showed greater adhering to the sites of meniscus injury, differentiate into cells resembling meniscal fibrochondrocytes, and improve both quality and quantity of meniscal regeneration.

Keywords: stem cells, regenerative medicine, osteoarthritis, knee

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2066 Ultrasonic Degradation of Acephate in Aqueous Solution: Effects of Operating Parameters

Authors: Naina S. Deshmukh, Manik P. Deosarkar

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With the wide production, consumption, and disposal of pesticides in the world, the concerns over their human and environmental health impacts are rapidly growing. Among developing treatment technologies, ultrasonication, as an emerging and promising technology for the removal of pesticides in the aqueous environment, has attracted the attention of many researchers in recent years. The degradation of acephate in aqueous solutions was investigated under the influence of ultrasound irradiation (20 kHz) in the presence of heterogeneous catalysts titanium dioxide (TiO2) and Zinc oxide (ZnO). The influence of various factors such as amount of catalyst (0.25, 0.5, 0.75, 1.0, 1.25 g/l), initial acephate concentration (100, 200, 300, 400 mg/l), and pH (3, 5, 7, 9, 11) were studied. The optimum catalyst dose was found to be 1 g/l of TiO2 and 1.25 g/l of ZnO for acephate at 100 mg/l, respectively. The maximum percentage degradation of acephate was observed at pH 11 for catalyst TiO2 and ZnO, respectively.

Keywords: ultrasonic degradation, acephate, TiO2, ZnO, heterogeneous catalyst

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2065 Photoluminescent Properties of Noble Metal Nanoparticles Supported Yttrium Aluminum Garnet Nanoparticles Doped with Cerium (Ⅲ) Ions

Authors: Mitsunobu Iwasaki, Akifumi Iseda

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Yttrium aluminum garnet doped with cerium (Ⅲ) ions (Y3Al5O12:Ce3+, YAG:Ce3+) has attracted a great attention because it can efficiently convert the blue light into a very broad yellow emission band, which produces white light emitting diodes and is applied for panel displays. To improve the brightness and resolution of the display, a considerable attention has been directed to develop fine phosphor particles. We have prepared YAG:Ce3+ nanophosphors by environmental-friendly wet process. The peak maximum of absorption spectra of surface plasmon of Ag nanopaticles are close to that of the excitation spectra (460 nm) of YAG:Ce3+. It can be expected that Ag nanoparticles supported onto the surface of YAG:Ce3+ (Ag-YAG:Ce3+) enhance the absorption of Ce3+ ions. In this study, we have prepared Ag-YAG:Ce3+ nanophosphors and investigated their photoluminescent properties. YCl3・6H2O and AlCl3・6H2O with a molar ratio of Y:Al=3:5 were dissolved in ethanol (100 ml), and CeCl3•7H2O (0.3 mol%) was further added to the above solution. Then, NaOH (4.6×10-2 mol) dissolved in ethanol (50 ml) was added dropwise to the mixture under reflux over 2 hours, and the solution was further refluxed for 1 hour. After cooling to room temperature, precipitates in the reaction mixture were heated at 673 K for 1 hour. After the calcination, the particles were immersed in AgNO3 solution for 1 hour, followed by sintering at 1123 K for 1 hour. YAG:Ce3+ were confirmed to be nanocrystals with a crystallite size of 50-80 nm in diameter. Ag nanoparticles supported onto YAG:Ce3+ were single nanometers in diameter. The excitation and emission spectra were 454 nm and 539 nm at a maximum wavelength, respectively. The emission intensity was maximum for Ag-YAG:Ce3+ immersed into 0.5 mM AgCl (Ag-YAG:Ce (0.5 mM)). The absorption maximum (461 nm) was increased for Ag-YAG:Ce3+ in comparison with that for YAG:Ce3+, indicating that the absorption was enhanced by the addition of Ag. The external and internal quantum efficiencies became 11.2 % and 36.9 % for Ag-YAG:Ce (0.5 mM), respectively. The emission intensity and absorption maximum of Ag-YAG:Ce (0.5 mM)×n (n=1, 2, 3) were increased with an increase of the number of supporting times (n), respectively. The external and internal quantum efficiencies were increased for the increase of n, respectively. The external quantum efficiency of Ag-YAG:Ce (0.5 mM) (n=3) became twice as large as that of YAG:Ce. In conclusion, Ag nanoparticles supported onto YAG:Ce3+ increased absorption and quantum efficiency. Therefore, the support of Ag nanoparticles enhanced the photoluminescent properties of YAG:Ce3+.

Keywords: plasmon, quantum efficiency, silver nanoparticles, yttrium aluminum garnet

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2064 Interior Architecture in the Anthropocene: Engaging the Subnature through the Intensification of Body-Surface Interaction

Authors: Verarisa Ujung

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The Anthropocene – as scientists define as a new geological epoch where human intervention has the dominant influence on the geological, atmospheric, and ecological processes challenges the contemporary discourse in architecture and interior. The dominant influence characterises the incapability to distinguish the notion of nature, subnature, human and non-human. Consequently, living in the Anthropocene demands sensitivity and responsiveness to heighten our sense of the rhythm of transformation and recognition of our environment as a product of natural, social and historical processes. The notion of subnature is particularly emphasised in this paper to investigate the poetic sense of living with subnature. It could be associated with the critical tool for exploring the aesthetic and programmatic implications of subnature on interiority. The ephemeral immaterial attached to subnature promotes the sense of atmospheric delineation of interiority, the very inner significance of body-surface interaction, which central to interior architecture discourse. This would then reflect human’s activities; examine the transformative change, the architectural motion and the traces that left between moments. In this way, engaging the notion of subnature enable us to better understand the critical subject on interiority and might provide an in-depth study on interior architecture. Incorporating the exploration on the form, materiality, and pattern of subnature, this research seeks to grasp the inner significance of micro to macro approaches so that the future of interior might be compelled to depend more on the investigation and development of responsive environment. To reflect upon the form, materiality and intensity of subnature that specifically characterized by the natural, social and historical processes, this research examines a volcanic land, White Island/Whakaari, New Zealand as the chosen site of investigation. Emitting various forms and intensities of subnatures - smokes, mud, sulphur gas, this volcanic land also open to the new inhabitation within the sulphur factory ruins that reflects human’s past occupation. In this way, temporal and natural selected manifestations of materiality, artefact, and performance can be traced out and might reveal the meaningful relations among space, inhabitation, and well-being of inhabitants in the Anthropocene.

Keywords: anthropocene, body, intensification, intensity, interior architecture, subnature, surface

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2063 Optimal Energy Consumption with Semiconductor Lamps

Authors: Pejman Hosseiniun, Rose Shayeghi, Alireza Farzaneh, Abolghasem Ghasempour

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Using LED lamps as lighting resources with new technology in designing lighting systems has been studied in this article. In this respect a history of LED emergence, its different manufacturing methods and technologies were revised, then their structure, light production line, its application and benefits in lighting industry has been evaluated. Finally, there is a comparison between these lamps and ordinary lamps to assess light parameters as well as energy consumption using DIALux software. Considering the results of analogies LED lamps have lower consumption and more lighting yield, therefore they are more economically feasible. Color variety, longer usage lap (circa 10 years) and compatibility with DC voltages are other LED lamps perquisites.

Keywords: LED, lighting efficiency, lighting intensity, luminance

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2062 Feasibility of Two Positive-Energy Schools in a Hot-Humid Tropical Climate: A Methodological Approach

Authors: Shashwat, Sandra G. L. Persiani, Yew Wah Wong, Pramod S. Kamath, Avinash H. Anantharam, Hui Ling Aw, Yann Grynberg

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Achieving zero-energy targets in existing buildings is known to be a difficult task, hence targets are addressed at new buildings almost exclusively. Although these ultra-efficient case-studies remain essential to develop future technologies and drive the concepts of Zero-energy, the immediate need to cut the consumption of the existing building stock remains unaddressed. This work aims to present a reliable and straightforward methodology for assessing the potential of energy-efficient upgrading in existing buildings. Public Singaporean school buildings, characterized by low energy use intensity and large roof areas, were identified as potential objects for conversion to highly-efficient buildings with a positive energy balance. A first study phase included the development of a detailed energy model for two case studies (a primary and a secondary school), based on the architectural drawings provided, site-visits and calibrated using measured end-use power consumption of different spaces. The energy model was used to demonstrate compliances or predict energy consumption of proposed changes in the two buildings. As complete energy monitoring is difficult and substantially time-consuming, short-term energy data was collected in the schools by taking spot measurements of power, voltage, and current for all the blocks of school. The figures revealed that the bulk of the consumption is attributed in decreasing order of magnitude to air-conditioning, plug loads, and lighting. In a second study-phase, a number of energy-efficient technologies and strategies were evaluated through energy-modeling to identify the alternatives giving the highest energy saving potential, achieving a reduction in energy use intensity down to 19.71 kWh/m²/y and 28.46 kWh/m²/y for the primary and the secondary schools respectively. This exercise of field evaluation and computer simulation of energy saving potential aims at a preliminary assessment of the positive-energy feasibility enabling future implementation of the technologies on the buildings studied, in anticipation of a broader and more widespread adoption in Singaporean schools.

Keywords: energy simulation, school building, tropical climate, zero energy buildings, positive energy

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2061 Rural-Urban Knowledge Transfer: Directions and Outcomes

Authors: J. Banski

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Regardless of residence place, the type of business and the social system, an individual or groups of people use the accumulated knowledge and continuously deepen and expand its scope. Knowledge is needed by human beings to carry out certain tasks, achieve desired goals or make decisions. Knowledge is an attribute of the people of a region and is identified with the total experience and information that its residents and institutions possess, including the ability to use it. It is subject to constant development, which is the result of both the deepening and exchange of knowledge among the residents of a particular area, as well as the influx of knowledge with newly arriving residents. A good example of the aforementioned processes is in rural areas, where we are dealing with two basic groups of people between whom knowledge transfer takes place. The first group is made up of people who have lived in the village for a long time, while the second group is made up of people who migrate temporarily or permanently to the countryside. The English-language literature uses the terms oldtimers and newcomers for these groups, respectively. Newcomers, usually possessing different life experiences, cultural patterns and competencies, can be rich sources of knowledge for villagers. At the same time, the latter, with different knowledge and experience, along with knowledge of local conditions and customs, can also be an important source of knowledge for incomers to the countryside. The countryside is a particularly interesting environment for studying social interactions and the accompanying transfer of knowledge. This is because it is characterized by a high intensity of neighborly contact and a high level of trust in the private sphere. As a result of the migratory influx of new residents, the social and cultural image of the countryside is changing due to the interpenetration of urban and rural life patterns. Research on rural-urban knowledge transfer is both an opportunity to halt negative trends in the social and economic development of rural areas and support the establishment of a basis for rural renewal. This paper discusses the results of research on urban-rural knowledge transfer based on case studies carried out in a dozen villages from different regions of Poland. Their purpose was to answer three basic research questions: 1) what types of knowledge are transferred between urban and rural residents? 2) what are the main directions and intensity in knowledge transfer? And 3) what are the consequences of knowledge transfer between urban and rural residents?

Keywords: rural areas, villages, newcomers, knowledge transfer, Poland

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2060 Evaluation of Total Antioxidant Activity (TAC) of Copper Oxide Decorated Reduced Graphene Oxide (CuO-rGO) at Different Stirring time

Authors: Aicha Bensouici, Assia Mili, Naouel Rdjem, Nacera Baali

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Copper oxide decorated reduced graphene oxide (GO) was obtained successfully using two steps route synthesis was used. Firstly, graphene oxide was obtained using a modified Hummers method by excluding sodium nitrate from starting materials. After washing-centrifugation routine pristine GO was decorated by copper oxide using a refluxation technique at 120°C during 2h, and an equal amount of GO and copper acetate was used. Three CuO-rGO nanocomposite samples types were obtained at 30min, 24h, and 7 day stirring time. TAC results show dose dependent behavior of CuO-rGO and confirm no influence of stirring time on antioxidant properties, 30min is considered as an optimal stirring condition.

Keywords: copper oxide, reduced graphene oxide, TAC, GO

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2059 Screening for Larvicidal Activity of Aqueous and Ethanolic Extracts of Fourteen Selected Plants and Formulation of a Larvicide against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) Larvae

Authors: Michael Russelle S. Alvarez, Noel S. Quiming, Francisco M. Heralde

Abstract:

This study aims to: a) obtain ethanolic (95% EtOH) and aqueous extracts of Selaginella elmeri, Christella dentata, Elatostema sinnatum, Curculigo capitulata, Euphorbia hirta, Murraya koenigii, Alpinia speciosa, Cymbopogon citratus, Eucalyptus globulus, Jatropha curcas, Psidium guajava, Gliricidia sepium, Ixora coccinea and Capsicum frutescens and screen them for larvicidal activities against Aedes aegypti (Linn.) and Aedes albopictus (Skuse) larvae; b) to fractionate the most active extract and determine the most active fraction; c) to determine the larvicidal properties of the most active extract and fraction against by computing their percentage mortality, LC50, and LC90 after 24 and 48 hours of exposure; and d) to determine the nature of the components of the active extracts and fractions using phytochemical screening. Ethanolic (95% EtOH) and aqueous extracts of the selected plants will be screened for potential larvicidal activity against Ae. aegypti and Ae. albopictus using standard procedures and 1% malathion and a Piper nigrum based ovicide-larvicide by the Department of Science and Technology as positive controls. The results were analyzed using One-Way ANOVA with Tukey’s and Dunnett’s test. The most active extract will be subjected to partial fractionation using normal-phase column chromatography, and the fractions subsequently screened to determine the most active fraction. The most active extract and fraction were subjected to dose-response assay and probit analysis to determine the LC50 and LC90 after 24 and 48 hours of exposure. The active extracts and fractions will be screened for phytochemical content. The ethanolic extracts of C. citratus, E. hirta, I. coccinea, G. sepium, M. koenigii, E globulus, J. curcas and C. frutescens exhibited significant larvicidal activity, with C. frutescens being the most active. After fractionation, the ethyl acetate fraction was found to be the most active. Phytochemical screening of the extracts revealed the presence of alkaloids, tannins, indoles and steroids. A formulation using talcum powder–300 mg fraction per 1 g talcum powder–was made and again tested for larvicidal activity. At 2 g/L, the formulation proved effective in killing all of the test larvae after 24 hours.

Keywords: larvicidal activity screening, partial purification, dose-response assay, capsicum frutescens

Procedia PDF Downloads 329
2058 Comparison of Computerized Dynamic Posturography and Functional Head Impulse Test Scores after of Hatha Yoga Practice and Resistance-Based Aerobic Exercise in Adult Female Yoga Practitioners

Authors: Çağla Aras, Kübra Bi̇nay, Aysberg Şamil önlü, Mine Baydan Aran, Dicle Aras

Abstract:

The purpose of the present research was to investigate the acute effects of 30-min hatha yoga and 30-min resistance-based aerobic exercise (RBAE) on computerized dynamic posturography (CDP) and functional head impulse test (fHIT) scores in adult female yoga practitioners. To reach this aim, ten participants executed CDP and fHIT three times in total: at rest, after yoga, and after RBAE. The yoga practice lasted a total of 30 minutes, including 25 min of asanas and 5 minutes of savasana. RBAE lasted a total of 30 minutes with an intensity of 70-75% of the heart rate reserve method. When the results were examined, no change was observed in any parameters of the fHIT scores due to resting or exercise implementation. On the contrary, some changes were observed in CDP test results depending on the type of exercise. The post-RBAE somatosensory and visual systems values were higher than resting (p<0.05). The composite balance score derived after RBAE was found to be improved when compared to post-yoga and resting values (p<0.01). Lastly, the post-RBAE vestibular system score was found to be statistically significantly higher than the post-Yoga values. In addition, it was observed that body composition parameters, especially decreasing BW, LBM, PBF, MBF and TBW, were associated with improved postural stability values. According to the results, it can be stated that neither hatha yoga nor resistance-based aerobic exercise has an acute effect on functional vestibulo-ocular reflex. In addition, although there was no change in balance level after yoga, it was observed that RBAE performed at 70-75% of the heart rate reserve and for 30 minutes had positive acute effects on postural stability and balance.

Keywords: hatha yoga, resistance training, aerobic training, high intensity training, computerized dynamic posturography, functional head impulse test

Procedia PDF Downloads 54
2057 Effect of Lime Stabilization on E. coli Destruction and Heavy Metal Bioavailability in Sewage Sludge for Agricultural Utilization

Authors: G. Petruzzelli, F. Pedron, M. Grifoni, A. Pera, I. Rosellini, B. Pezzarossa

Abstract:

The addition of lime as Ca(OH)2 to sewage sludge to destroy pathogens (Escherichia coli), was evaluated also in relation to heavy metal bioavailability. The obtained results show that the use of calcium hydroxide at the dose of 3% effectively destroyed pathogens ensuring the stability at high pH values over long period and the duration of the sewage sludge stabilization. In general, lime addition decreased the total extractability of heavy metals indicating a reduced bioavailability of these elements. This is particularly important for a safe utilization in agricultural soils to reduce the possible transfer of heavy metals to the food chain.

Keywords: biological sludge, Ca(OH)2, copper, pathogens, sanitation, zinc

Procedia PDF Downloads 426
2056 Multilevel of Factors Affected Optimal Adherence to Antiretroviral Therapy and Viral Suppression amongst HIV-Infected Prisoners in South Ethiopia: A Prospective Cohort Study

Authors: Terefe Fuge, George Tsourtos , Emma Miller

Abstract:

Objectives: Maintaining optimal adherence and viral suppression in people living with HIV (PLWHA) is essential to ensure both preventative and therapeutic benefits of antiretroviral therapy (ART). Prisoners bear a particularly high burden of HIV infection and are highly likely to transmit to others during and after incarceration. However, the level of adherence and viral suppression, as well as its associated factors in incarcerated populations in low-income countries is unknown. This study aimed to determine the prevalence of non-adherence and viral failure, and contributing factors to this amongst prisoners in South Ethiopia. Methods: A prospective cohort study was conducted between June 1, 2019 and July 31, 2020 to compare the level of adherence and viral suppression between incarcerated and non-incarcerated PLWHA. The study involved 74 inmates living with HIV (ILWHA) and 296 non-incarcerated PLWHA. Background information including sociodemographic, socioeconomic, psychosocial, behavioural, and incarceration-related characteristics was collected using a structured questionnaire. Adherence was determined based on participants’ self-report and pharmacy refill records, and plasma viral load measurements which were undertaken within the study period were prospectively extracted to determine viral suppression. Various univariate and multivariate regression models were used to analyse data. Results: Self-reported dose adherence was approximately similar between ILWHA and non-incarcerated PLWHA (81% and 83% respectively), but ILWHA had a significantly higher medication possession ratio (MPR) (89% vs 75%). The prevalence of viral failure (VF) was slightly higher (6%) in ILWHA compared to non-incarcerated PLWHA (4.4%). The overall dose non-adherence (NA) was significantly associated with missing ART appointments, level of satisfaction with ART services, patient’s ability to comply with a specified medication schedule and types of methods used to monitor the schedule. In ILWHA specifically, accessing ART services from a hospital compared to a health centre, an inability to always attend clinic appointments, experience of depression and a lack of social support predicted NA. VF was significantly higher in males, people of age 31-35 years and in those who experienced social stigma, regardless of their incarceration status. Conclusions: This study revealed that HIV-infected prisoners in South Ethiopia were more likely to be non-adherent to doses and so to develop viral failure compared to their non-incarcerated counterparts. A multitude of factors was found to be responsible for this requiring multilevel intervention strategies focusing on the specific needs of prisoners.

Keywords: Adherence , Antiretroviral therapy, Incarceration, South Ethiopia, Viral suppression

Procedia PDF Downloads 135
2055 Influence of Wavelengths on Photosensitivity of Copper Phthalocyanine Based Photodetectors

Authors: Lekshmi Vijayan, K. Shreekrishna Kumar

Abstract:

We demonstrated an organic field effect transistor based photodetector using phthalocyanine as the active material that exhibited high photosensitivity under varying light wavelengths. The thermally grown SiO₂ layer on silicon wafer act as a substrate. The critical parameters, such as photosensitivity, responsivity and detectivity, are comparatively high and were 3.09, 0.98AW⁻¹ and 4.86 × 10¹⁰ Jones, respectively, under a bias of 5 V and a monochromatic illumination intensity of 4mW cm⁻². The photodetector has a linear I-V curve with a low dark current. On comparing photoresponse of copper phthalocyanine at four different wavelengths, 560 nm shows better photoresponse and the highest value of photosensitivity is also obtained.

Keywords: photodetector, responsivity, photosensitivity, detectivity

Procedia PDF Downloads 178
2054 Interaction between the Main Crack and Dislocation in the Glass Material

Authors: A. Mezzidi, H. Hamli Benzahar

Abstract:

The present study evaluates the stress and stress intensity factor during the propagation of a crack at presence of a dislocation near of crack tip. The problem is formulated using a glass material having an equivalent elasticity modulus and a Poisson ratio. In this research work, the proposed material is a plate form with a main crack in one of these ends and a dislocation near this crack, subjected to tensile stresses according to the mode 1 opening. For each distance between the two cracks, we can determine these stresses. This study is treated by finite elements method by using the software (ABAQUS) rate. It is shown here in that obtained results agreed with those determined by other researchers

Keywords: crack, dislocation, finite element, glass

Procedia PDF Downloads 372
2053 The Influence of Gender on Itraconazole Pharmacokinetic Parameters in Healthy Adults

Authors: Milijana N. Miljkovic, Viktorija M. Dragojevic-Simic, Nemanja K. Rancic, Vesna M. Jacevic, Snezana B. Djordjevic, Momir M. Mikov, Aleksandra M. Kovacevic

Abstract:

Itraconazole (ITZ) is a weak base and extremely lipophilic compound, with water solubility as a rate-limiting step in its absorption from the gastrointestinal tract. Its absolute bioavailability, about 55%, is maximal when its oral formulation, capsules, are taken immediately after a full meal. Peak plasma concentrations (Cmax) are reached within 2 to 5 hrs after their administration. ITZ undergoes extensive hepatic metabolism by human CYP3A4 isoenzyme and more than 30 different metabolites have been identified. One of the main ones is hydroxyitraconazole (HITZ), in which plasma concentrations are almost twice higher than those of ITZ. Gender differences in drug PK (Pharmacokinetics) have already been recognized, but variations in metabolism are believed to be their major cause. The aim of the study was to investigate the influence of gender on ITZ PK parameters after administration of oral capsule formulation, following 100 mg single dosing in healthy adult volunteers under fed conditions. The single-center, open-label PK study was performed. PK analyses included PK parameters obtained after a single 100 mg dose administration of itraconazole capsules to 48 females and 66 males. Blood samples were collected at pre-dose and up to 72.0 h after administration (1.0, 2.0, 3.0, 3.5, 4.0, 4.5, 5.0, 5.5, 6.0, 7.0, 9.0, 12.0, 24.0, 36.0 and 72.0 hrs). The calculated pharmacokinetic parameters, based on the plasma concentrations of itraconazole and hydroxyitraconazole, were Cmax, AUClast, and AUCtot. Plasma concentrations of ITZ and HITZ were determined using a validated liquid chromatographic method with mass spectrometric detection, while pharmacokinetic parameters were estimated using non-compartmental methods. The pharmacokinetic analyses were performed using Kinetica software version 5.0. The mean value of ITZ Cmaxmen was 74.79 ng/ml, and Cmaxwomen was 51.291 ng/ml (independent samples test; p = 0.005). Hydroxyitraconazole had a mean value of Cmaxmen 106.37 ng/ml, and the mean value Cmaxwomen was 70.05 ng/ml. Women had, on average, lower AUClast and Cmax than men. AUClastmen for ITZ was 736.02 ng/mL*h and AUClastwomen was 566.62 ng/mL*h, while AUClastmen for HITZ was 1154.80 was ng/mL*h and AUClastwomen for HITZ was 708.12 ng/mL*h (independent samples test; p = 0.033). The mean values of ITZ AUCtotmen were 884.73 ng/mL*h and AUCtotwomen was 685.10 ng/mL*h. AUCtotmen for HITZ was 1290.41 ng/mL*h, while AUCtotwomen for HIZT was 788.60 ng/mL*h (p < 0.001). The results could point out to lower oral bioavailability of ITZ in women, since values of Cmax, AUClast, and AUCtot of both ITZ and HITZ were significantly lower in women than in men, respectively. The reason may be higher expression and activity of CYP3A4 in women than in men, but there also may be differences in other PK parameters. High variability of both ITZ and HITZ concentrations in both genders confirmed that ITZ is a highly variable drug. Further examinations of its PK are needed to justify strategies for therapeutic drug monitoring in patients treated by this antifungal agent.

Keywords: itraconazole, gender, hydroxyitraconazole, pharmacokinetics

Procedia PDF Downloads 137
2052 Assessment of the Efficacy of Routine Medical Tests in Screening Medical Radiation Staff in Shiraz University of Medical Sciences Educational Centers

Authors: Z. Razi, S. M. J. Mortazavi, N. Shokrpour, Z. Shayan, F. Amiri

Abstract:

Long-term exposure to low doses of ionizing radiation occurs in radiation health care workplaces. Although doses in health professions are generally very low, there are still matters of concern. The radiation safety program promotes occupational radiation safety through accurate and reliable monitoring of radiation workers in order to effectively manage radiation protection. To achieve this goal, it has become mandatory to implement health examination periodically. As a result, based on the hematological alterations, working populations with a common occupational radiation history are screened. This paper calls into question the effectiveness of blood component analysis as a screening program which is mandatory for medical radiation workers in some countries. This study details the distribution and trends of changes in blood components, including white blood cells (WBCs), red blood cells (RBCs) and platelets as well as received cumulative doses from occupational radiation exposure. This study was conducted among 199 participants and 100 control subjects at the medical imaging departments at the central hospital of Shiraz University of Medical Sciences during the years 2006–2010. Descriptive and analytical statistics, considering the P-value<0.05 as statistically significance was used for data analysis. The results of this study show that there is no significant difference between the radiation workers and controls regarding WBCs and platelet count during 4 years. Also, we have found no statistically significant difference between the two groups with respect to RBCs. Besides, no statistically significant difference was observed with respect to RBCs with regards to gender, which has been analyzed separately because of the lower reference range for normal RBCs levels in women compared to men and. Moreover, the findings confirm that in a separate evaluation between WBCs count and the personnel’s working experience and their annual exposure dose, results showed no linear correlation between the three variables. Since the hematological findings were within the range of control levels, it can be concluded that the radiation dosage (which was not more than 7.58 mSv in this study) had been too small to stimulate any quantifiable change in medical radiation worker’s blood count. Thus, use of more accurate method for screening program based on the working profile of the radiation workers and their accumulated dose is suggested. In addition, complexity of radiation-induced functions and the influence of various factors on blood count alteration should be taken into account.

Keywords: blood cell count, mandatory testing, occupational exposure, radiation

Procedia PDF Downloads 461
2051 Protective Effect of Ginger Root Extract on Dioxin-Induced Testicular Damage in Rats

Authors: Hamid Abdulroof Saleh

Abstract:

Background: Dioxins are one of the most widely distributed environmental pollutants. Dioxins consist of feedstock during the preparation of some industries, such as the paper industry as they can be produced in the atmosphere during the process of burning garbage and waste, especially medical waste. Dioxins can be found in the adipose tissues of animals in the food chain as well as in human breast milk. 2,3,7,8-Tetrachlorodibenzo-pdioxin (TCDD) is the most toxic component of a large group of dioxins. Humans are exposed to TCDD through contaminated food items like meat, fish, milk products, eggs etc. Recently, natural formulations relating to reducing or eliminating TCDD toxicity have been in focus. Ginger rhizome (Zingiber officinale R., family: Zingiberaceae), is used worldwide as a spice. Both antioxidative and androgenic activity of Z. officinale was reported in animal models. Researchers showed that ginger oil has dominative protective effect on DNA damage and might act as a scavenger of oxygen radical and might be used as an antioxidant. Aim of the work: The present study was undertaken to evaluate the toxic effect of TCDD on the structure and histoarchitecture of the testis and the protective role of co-administration of ginger root extract to prevent this toxicity. Materials & Methods: Male adult rats of Sprague-Dawley strain were assigned to four groups, eight rats in each; control group, dioxin treated group (given TCDD at the dose of 100 ng/kg Bwt/day by gavage), ginger treated group (given 50 mg/kg Bwt/day of ginger root extract by gavage), dioxin and ginger treated group (given TCDD at the dose of 100 ng/kg Bwt/day and 50 mg/kg Bwt/day of ginger root extract by gavages). After three weeks, rats were weighed and sacrificed where testis were removed and weighted. The testes were processed for routine paraffin embedding and staining. Tissue sections were examined for different morphometric and histopathological changes. Results: Dioxin administration showed a harmful effects in the body, testis weight and other morphometric parameters of the testis. In addition, it produced varying degrees of damage to the seminiferous tubules, which were shrunken and devoid of mature spermatids. The basement membrane was disorganized with vacuolization and loss of germinal cells. The co-administration of ginger root extract showed obvious improvement in the above changes and showed reversible morphometric and histopathological changes of the seminiferous tubules. Conclusion: Ginger root extract treatment in this study was successful in reversing all morphometric and histological changes of dioxin testicular damage. Therefore, it showed a protective effect on testis against dioxin toxicity.

Keywords: dioxin, ginger, rat, testis

Procedia PDF Downloads 418
2050 Mixed Mode Fracture Analyses Using Finite Element Method of Edge Cracked Heavy Annulus Pulley

Authors: Bijit Kalita, K. V. N. Surendra

Abstract:

The pulley works under both compressive loading due to contacting belt in tension and central torque due to cause rotation. In a power transmission system, the belt pulley assemblies offer a contact problem in the form of two mating cylindrical parts. In this work, we modeled a pulley as a heavy two-dimensional circular disk. Stress analysis due to contact loading in the pulley mechanism is performed. Finite element analysis (FEA) is conducted for a pulley to investigate the stresses experienced on its inner and outer periphery. In most of the heavy-duty applications, most frequently used mechanisms to transmit power in applications such as automotive engines, industrial machines, etc. is Belt Drive. Usually, very heavy circular disks are used as pulleys. A pulley could be entitled as a drum and may have a groove between two flanges around the circumference. A rope, belt, cable or chain can be the driving element of a pulley system that runs over the pulley inside the groove. A pulley is experienced by normal and shear tractions on its contact region in the process of motion transmission. The region may be belt-pulley contact surface or pulley-shaft contact surface. In 1895, Hertz solved the elastic contact problem for point contact and line contact of an ideal smooth object. Afterward, this hypothesis is generally utilized for computing the actual contact zone. Detailed stress analysis in such contact region of such pulleys is quite necessary to prevent early failure. In this paper, the results of the finite element analyses carried out on the compressed disk of a belt pulley arrangement using fracture mechanics concepts are shown. Based on the literature on contact stress problem induced in the wide field of applications, generated stress distribution on the shaft-pulley and belt-pulley interfaces due to the application of high-tension and torque was evaluated in this study using FEA concepts. Finally, the results obtained from ANSYS (APDL) were compared with the Hertzian contact theory. The study is mainly focused on the fatigue life estimation of a rotating part as a component of an engine assembly using the most famous Paris equation. Digital Image Correlation (DIC) analyses have been performed using the open-source software. From the displacement computed using the images acquired at a minimum and maximum force, displacement field amplitude is computed. From these fields, the crack path is defined and stress intensity factors and crack tip position are extracted. A non-linear least-squares projection is used for the purpose of the estimation of fatigue crack growth. Further study will be extended for the various application of rotating machinery such as rotating flywheel disk, jet engine, compressor disk, roller disk cutter etc., where Stress Intensity Factor (SIF) calculation plays a significant role on the accuracy and reliability of a safe design. Additionally, this study will be progressed to predict crack propagation in the pulley using maximum tangential stress (MTS) criteria for mixed mode fracture.

Keywords: crack-tip deformations, contact stress, stress concentration, stress intensity factor

Procedia PDF Downloads 124
2049 Modeling of Crack Growth in Railway Axles under Static Loading

Authors: Zellagui Redouane, Bellaouar Ahmed, Lachi Mohammed

Abstract:

The railway axles are the essential parts in the bogie of train, and its failure creates a big problem in the railway transport; during the work of this parts we noticed a premature deterioration. The aim has been presented a predictive model allowing the identification of the probable causes that are the cause of these premature deterioration. The results are employed for predicting fatigue crack growth in the railway axle, Also we want to present the variation value of stress intensity factor in different positions of elliptical crack tip. The modeling of axle in performed by the SOLID WORKS software and imported into ANSYS.

Keywords: crack growth, static load, railway axle, lifetime

Procedia PDF Downloads 364
2048 Comparison of Soils of Hungarian Dry and Humid Oak Forests Based on Changes in Nutrient Content

Authors: István Fekete, Imre Berki, Áron Béni, Katalin Juhos, Marianna Makádi, Zsolt Kotroczó

Abstract:

The average annual precipitation significantly influences the moisture content of the soils and, through this, the decomposition of the organic substances in the soils, the leaching of nutrients from the soils, and the pH of the soils. Climate change, together with the lengthening of the vegetation period and the increasing CO₂ level, can increase the amount of biomass that is formed. Degradation processes, which accelerate as the temperature increases and slow down due to the drying climate, and the change in the degree of leaching can cancel out or strengthen each other's effects. In the course of our research, we looked for oak forests with climate-zonal soils where the geological, geographical and ecological background conditions are as similar as possible, apart from the different annual precipitation averages and the differences that can arise from them. We examined 5 dry and 5 humid Hungarian oak soils. Climate change affects the soils of drier and wetter forests differently. The aim of our research was to compare the content of carbon, nitrogen and some other nutrients, as well as the pH of the soils of humid and dry forests. Showing the effects of the drier climate on the tested soil parameters. In the case of the examined forest soils, we found a significant difference between the soils of dry and humid forests: in the case of the annual average precipitation values (p≥ 0.0001, for dry forest soils: 564±5.2 mm; for humid forest soils: 716±3.8 mm) for pH (p= 0.0004, for dry forest soils: 5.49±0.16; for wet forest soils: 5.36±0.21); for C content (p= 0.0054, for dry forest soils: 6.92%±0.59; for humid forest soils 3.09%±0.24), for N content (p= 0.0022, dry forest in the case of soils: 0.44%±0.047; in the case of humid forest soils: 0.23%±0.013), for the K content (p=0.0017, in the case of dry forest soils: 5684±732 (mg/kg); in the case of humid forest soils 2169±196 (mg/kg)), for the Ca content (p= 0.0096, for dry forest soils: 8207±2118 (mg/kg); for wet forest soils 957±320 (mg/kg)). No significant difference was found in the case of Mg. In a wetter environment, especially if the moisture content of the soil is also optimal for the decomposing organisms during the growing season, the decomposition of organic residues accelerates, and the processes of leaching from the soil are also intensified. The different intensity of the leaching processes is also well reflected in the quantitative differences of Ca and K, and in connection with these, it is also reflected in the difference in pH values. The differences in the C and N content can be explained by differences in the intensity of the decomposition processes. In addition to warming, drying is expected in a significant part of Hungary due to climate change. Thus, the comparison of the soils of dry and humid forests allows us to predict the subsequent changes in the case of the examined parameters.

Keywords: soil nutrients, precipitation difference, climate change, organic matter decomposition, leaching

Procedia PDF Downloads 74
2047 Optimization of Real Time Measured Data Transmission, Given the Amount of Data Transmitted

Authors: Michal Kopcek, Tomas Skulavik, Michal Kebisek, Gabriela Krizanova

Abstract:

The operation of nuclear power plants involves continuous monitoring of the environment in their area. This monitoring is performed using a complex data acquisition system, which collects status information about the system itself and values of many important physical variables e.g. temperature, humidity, dose rate etc. This paper describes a proposal and optimization of communication that takes place in teledosimetric system between the central control server responsible for the data processing and storing and the decentralized measuring stations, which are measuring the physical variables. Analyzes of ongoing communication were performed and consequently the optimization of the system architecture and communication was done.

Keywords: communication protocol, transmission optimization, data acquisition, system architecture

Procedia PDF Downloads 518