Search results for: background gamma radiation
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 6158

Search results for: background gamma radiation

5318 Enhanced Physiological Response of Blood Pressure and Improved Performance in Successive Divided Attention Test Seen with Classical Instrumental Background Music Compared to Controls

Authors: Shantala Herlekar

Abstract:

Introduction: Entrainment effect of music on cardiovascular parameters is well established. Music is being used in the background by medical students while studying. However, does it really help them relax faster and concentrate better? Objectives: This study was done to compare the effects of classical instrumental background music versus no music on blood pressure response over time and on successively performed divided attention test in Indian and Malaysian 1st-year medical students. Method: 60 Indian and 60 Malaysian first year medical students, with an equal number of girls and boys were randomized into two groups i.e music group and control group thus creating four subgroups. Three different forms of Symbol Digit Modality Test (to test concentration ability) were used as a pre-test, during music/control session and post-test. It was assessed using total, correct and error score. Simultaneously, multiple Blood Pressure recordings were taken as pre-test, during 1, 5, 15, 25 minutes during music/control (+SDMT) and post-test. The music group performed the test with classical instrumental background music while the control group performed it in silence. Results were analyzed using students paired t test. p value < 0.05 was taken as statistically significant. A drop in BP recording was indicative of relaxed state and a rise in BP with task performance was indicative of increased arousal. Results: In Symbol Digit Modality Test (SDMT) test, Music group showed significant better results for correct (p = 0.02) and total (p = 0.029) scores during post-test while errors reduced (p = 0.002). Indian music group showed decline in post-test error scores (p = 0.002). Malaysian music group performed significantly better in all categories. Blood pressure response was similar in music and control group with following variations, a drop in BP at 5minutes, being significant in music group (p < 0.001), a steep rise in values till 15minutes (corresponding to SDMT test) also being significant only in music group (p < 0.001) and the Systolic BP readings in controls during post-test were at lower levels compared to music group. On comparing the subgroups, not much difference was noticed in recordings of Indian student’s subgroups while all the paired-t test values in the Malaysian music group were significant. Conclusion: These recordings indicate an increased relaxed state with classical instrumental music and an increased arousal while performing a concentration task. Music used in our study was beneficial to students irrespective of their nationality and preference of music type. It can act as an “active coping” strategy and alleviate stress within a very short period of time, in our study within a span of 5minutes. When used in the background, during task performance, can increase arousal which helps the students perform better. Implications: Music can be used between lectures for a short time to relax the students and help them concentrate better for the subsequent classes, especially for late afternoon sessions.

Keywords: blood pressure, classical instrumental background music, ethnicity, symbol digit modality test

Procedia PDF Downloads 141
5317 Mixtures of Length-Biased Weibull Distributions for Loss Severity Modelling

Authors: Taehan Bae

Abstract:

In this paper, a class of length-biased Weibull mixtures is presented to model loss severity data. The proposed model generalizes the Erlang mixtures with the common scale parameter, and it shares many important modelling features, such as flexibility to fit various data distribution shapes and weak-denseness in the class of positive continuous distributions, with the Erlang mixtures. We show that the asymptotic tail estimate of the length-biased Weibull mixture is Weibull-type, which makes the model effective to fit loss severity data with heavy-tailed observations. A method of statistical estimation is discussed with applications on real catastrophic loss data sets.

Keywords: Erlang mixture, length-biased distribution, transformed gamma distribution, asymptotic tail estimate, EM algorithm, expectation-maximization algorithm

Procedia PDF Downloads 224
5316 Family Background and Extracurricular English Learning: Ethnography of Language Ideologies and Language Management in China

Authors: Yan Ma

Abstract:

Parents in China now are of great enthusiasm to outsource extracurricular lessons and activities to ensure their children’s English learning. This study draws on one year of ethnographic observations and interviews with parents and children in 6 families in Shaoxing, a small city in East China, to explore how parents in different social classes differ in their ideology and investment practice towards their children’s English education. Through comparative analysis, the study reveals though all the families acknowledge the importance of English and there are great similarities among families in the same social class, differences are distinct among those in different social classes with regard to how they perceived the importance and what measures they take. The results also reflect China’s sociocultural and socioeconomic factors that underlined the heated wave of English learning as well as the social, cultural and economic conditions of different families that exert a decisive influence on their children’s learning experience.

Keywords: family background, extracurricular English learning, language ideologies, language management

Procedia PDF Downloads 110
5315 Effect of Carbon Nanotubes on Ultraviolet and Immersion Stability of Diglycidyl Ether of Bisphenol A Epoxy Coating

Authors: Artemova Anastasiia, Shen Zexiang, Savilov Serguei

Abstract:

The marine environment is very aggressive for a number of factors, such as moisture, temperature, winds, ultraviolet radiation, chloride ion concentration, oxygen concentration, pollution, and biofouling, all contributing to marine corrosion. Protective organic coatings provide protection either by a barrier action from the layer, which is limited due to permeability to water and oxygen or from active corrosion inhibition and cathodic protection due to the pigments in the coating. Carbon nanotubes can play not only barrier effect but also passivation effect via adsorbing molecular species of oxygen, hydroxyl, chloride and sulphate anions. Multiwall carbon nanotubes composite provide very important properties such as mechanical strength, non-cytotoxicity, outstanding thermal and electrical conductivity, and very strong absorption of ultraviolet radiation. The samples of stainless steel (316L) coated by epoxy resin with carbon nanotubes-based pigments were exposed to UV irradiation (340nm), and immersion to the sodium chloride solution for 1000h and corrosion behavior in 3.5 wt% sodium chloride (NaCl) solution was investigated. Experimental results showed that corrosion current significantly decreased in the presence of carbon nanotube-based materials, especially nitrogen-doped ones, in the composite coating. Importance of the structure and composition of the pigment materials and its composition was established, and the mechanism of the protection was described. Finally, the effect of nitrogen doping on the corrosion behavior was investigated. The pigment-polymer crosslinking improves the coating performance and the corrosion rate decreases in comparison with pure epoxy coating from 5.7E-05 to 1.4E-05mm/yr for the coating without any degradation; in more than 6 times for the coating after ultraviolet degradation; and more than 16% for the coatings after immersion degradation.

Keywords: corrosion, coating, carbon nanotubes, degradation

Procedia PDF Downloads 159
5314 Assessment of Pollution of the Rustavi City’s Atmosphere with Microaerosols

Authors: Natia Gigauri, Aleksandre Surmava

Abstract:

According to observational data, experimental measurements, and numerical modeling, is assessed pollution of one of the industrial centers of Georgia, Rustavi city’s atmosphere with microaerosols. Monthly, daily and hourly changes of the concentrations of PM2.5 and PM10 in the city atmosphere are analyzed. It is accepted that PM2.5 concentrations are always lower than PM10 concentrations, but their change curve is the same. In addition, it has been noted that the maximum concentrations of particles in the atmosphere of Rustavi city will be reached at any part of the day, which is determined by the total impact of the traffic flow and industrial facilities. By numerical modeling has calculated the influence of background western light air and gentle and fresh breeze on the distribution of PM particles in the atmosphere. Calculations showed that background light air and gentle breeze lead to an increase the concentrations of microaerosols in the city's atmosphere, while fresh breeze contribute to the dispersion of dusty clouds. As a result, the level of dust in the city is decreasing, but the distribution area is expanding.

Keywords: pollution, modelling, PM2.5, PM10, experimental measurement

Procedia PDF Downloads 89
5313 Studying the Photodegradation Behavior of Microplastics Released from Agricultural Plastic Products to the Farmland

Authors: Maryam Salehi, Gholamreza Bonyadinejad

Abstract:

The application of agricultural plastic products like mulch, greenhouse covers, and silage films is increasing due to their economic benefits in providing an early and better-quality harvest. In 2015, the 4 million tons (valued a 10.6 million USD) global market for agricultural plastic films was estimated to grow by 5.6% per year through 2030. Despite the short-term benefits provided by plastic products, their long-term sustainability issues and negative impacts on soil health are not well understood. After their removal from the field, some plastic residuals remain in the soil. Plastic residuals in farmlands may fragment to small particles called microplastics (d<5mm). The microplastics' exposure to solar radiation could alter their surface chemistry and make them susceptible to fragmentation. Thus, this study examined the photodegradation of low density polyethylene as the model microplastics that are released to the agriculture farmland. The variation of plastic’s surface chemistry, morphology, and bulk characteristics were studied after accelerated UV-A radiation experiments and sampling from an agricultural field. The Attenuated Total Reflectance Fourier Transform Spectroscopy (ATR-FTIR) and X-ray Photoelectron Spectroscopy (XPS) demonstrated the formation of oxidized surface functional groups onto the microplastics surface due to the photodegradation. The Differential Scanning Calorimetry (DSC) analysis revealed an increased crystallinity for the photodegraded microplastics compared to the new samples. The gel permeation chromatography (GPC) demonstrated the reduced molecular weight for the polymer due to the photodegradation. This study provides an important opportunity to advance understanding of soil pollution. Understanding the plastic residuals’ variations as they are left in the soil is providing a critical piece of information to better estimate the microplastics' impacts on environmental biodiversity, ecosystem sustainability, and food safety.

Keywords: soil health, plastic pollution, sustainability, photodegradation

Procedia PDF Downloads 220
5312 Solar-Plasma Reactors for a Zero-Emission Economy

Authors: Dassou Nagassou

Abstract:

Recent increase in frequency and severity of climatic impacts throughout the world has put a particular emphasis on the urgency to address the anthropogenic greenhouse gas emissions. The latter, mainly composed of carbon dioxide are responsible for the global warming of planet earth. Despite efforts to transition towards a zero-emission economy, manufacturing industries, electricity generation power plants, and transportation sectors continue to encounter challenges which hinder their progress towards a full decarbonization. The growing energy demand from both developed and under-developed economies exacerbates the situation and as a result, more carbon dioxide is discharged into the atmosphere. This situation imposes a lot of constraints on industries which are involved i.e., manufacturing industries, transportation, and electricity generation which must navigate the stringent environmental regulations in order to remain profitable. Existing solutions such as energy efficiencies, green materials (life cycle analysis), and many more have fallen short to address the problem due to their inadaptation to existing infrastructures, low efficiencies, and prohibitive costs. The proposed technology exploits the synergistic interaction between solar radiation and plasma to boost a direct decomposition of the molecules of carbon dioxide while producing alternative fuels which can be used to sustain on-site high-temperature processes via 100% solar energy harvesting in the form of photons and electricity. The advantages of this technology and its ability to be easily integrated into existing systems make it appealing for the industry which can now afford to fast track on the path towards full decarbonization, thanks to the solar plasma reactor. Despite the promising experimental results which proved the viability of this concept, solar-plasma reactors require further investigations to understand the synergistic interactions between plasma and solar radiation for a potential technology scale-up.

Keywords: solar, non-equilibrium, plasma, reactor, greenhouse-gases, solar-fuels

Procedia PDF Downloads 58
5311 The Kinks, the Solitons, and the Shocks in Series Connected Discrete Josephson Transmission Lines

Authors: Eugene Kogan

Abstract:

We analytically study the localized running waves in the discrete Josephson transmission lines (JTL), constructed from Josephson junctions (JJ) and capacitors. The quasi-continuum approximation reduces the calculation of the running wave properties to the problem of equilibrium of an elastic rod in the potential field. Making additional approximations, we reduce the problem to the motion of the fictitious Newtonian particle in the potential well. We show that there exist running waves in the form of supersonic kinks and solitons and calculate their velocities and profiles. We show that the nonstationary smooth waves, which are small perturbations on the homogeneous non-zero background, are described by Korteweg-de Vries equation, and those on zero background -by the modified Korteweg-de Vries equation. We also study the effect of dissipation on the running waves in JTL and find that in the presence of the resistors, shunting the JJ and/or in series with the ground capacitors, the only possible stationary running waves are the shock waves, whose profiles are also found.

Keywords: Josephson transmission line, shocks, solitary waves, nonlinear waves

Procedia PDF Downloads 114
5310 Design, Shielding and Infrastructure of an X-Ray Diagnostic Imaging Area

Authors: D. Diaz, C. Guevara, P. Rey

Abstract:

This paper contains information about designing, shielding and protocols building in order to avoid ionizing radiation in X-Rays imaging areas as generated by X-Ray, mammography equipment, computed tomography equipment and digital subtraction angiography equipment, according to global standards. Furthermore, tools and elements about infrastructure to improve protection over patients, physicians and staff involved in a diagnostic imaging area are presented. In addition, technical parameters about each machine and the architecture designs and maps are described.

Keywords: imaging area, X-ray, shielding, dose

Procedia PDF Downloads 448
5309 Thermal and Solar Performances of Adsorption Solar Refrigerating Machine

Authors: Nadia Allouache

Abstract:

Solar radiation is by far the largest and the most world’s abundant, clean and permanent energy source. The amount of solar radiation intercepted by the Earth is much higher than annual global energy use. The energy available from the sun is greater than about 5200 times the global world’s need in 2006. In recent years, many promising technologies have been developed to harness the sun's energy. These technologies help in environmental protection, economizing energy, and sustainable development, which are the major issues of the world in the 21st century. One of these important technologies is the solar cooling systems that make use of either absorption or adsorption technologies. The solar adsorption cooling systems are good alternative since they operate with environmentally benign refrigerants that are natural, free from CFCs, and therefore they have a zero ozone depleting potential (ODP). A numerical analysis of thermal and solar performances of an adsorption solar refrigerating system using different adsorbent/adsorbate pairs such as activated carbon AC35 and activated carbon BPL/Ammoniac; is undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber that is the most important component of the machine. The Wilson and Dubinin- Astakhov models of the solid-adsorbat equilibrium are used to calculate the adsorbed quantity. The porous medium is contained in the annular space and the adsorber is heated by solar energy. Effect of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The performances of the system that depends on the incident global irradiance during a whole day depends on the weather conditions: the condenser temperature and the evaporator temperature. The AC35/methanol pair is the best pair comparing to the BPL/Ammoniac in terms of system performances.

Keywords: activated carbon-methanol pair, activated carbon-ammoniac pair, adsorption, performance coefficients, numerical analysis, solar cooling system

Procedia PDF Downloads 72
5308 Charging-Vacuum Helium Mass Spectrometer Leak Detection Technology in the Application of Space Products Leak Testing and Error Control

Authors: Jijun Shi, Lichen Sun, Jianchao Zhao, Lizhi Sun, Enjun Liu, Chongwu Guo

Abstract:

Because of the consistency of pressure direction, more short cycle, and high sensitivity, Charging-Vacuum helium mass spectrometer leak testing technology is the most popular leak testing technology for the seal testing of the spacecraft parts, especially the small and medium size ones. Usually, auxiliary pump was used, and the minimum detectable leak rate could reach 5E-9Pa•m3/s, even better on certain occasions. Relative error is more important when evaluating the results. How to choose the reference leak, the background level of helium, and record formats would affect the leak rate tested. In the linearity range of leak testing system, it would reduce 10% relative error if the reference leak with larger leak rate was used, and the relative error would reduce obviously if the background of helium was low efficiently, the record format of decimal was used, and the more stable data were recorded.

Keywords: leak testing, spacecraft parts, relative error, error control

Procedia PDF Downloads 456
5307 γ-Irradiation of Oat β- Glucan: Effect on Antioxidant and Antiproliferative Properties

Authors: Asima Shah, F. A. Masoodi, Adil Gani, Bilal Ahmad Ashwar

Abstract:

The present study was designed to evaluate the effect of γ-rays on the antioxidant and antiproliferative potential of β-glucan isolated from oats. The β-glucan was irradiated with 0, 2, 6, and 10 kGy by gamma ray. The samples were characterized by FT-IR, GPC, and quantitative estimation by Megazyme β-glucan assay kit. The average molecular weight of non-irradiated β-glucan was 199 kDa that decreased to 70 kDa at 10 kGy. Both FT-IR spectrum and chemical analysis revealed that the extracted β-glucan was pure having minor impurities. Antioxidant activity was evaluated by DPPH, lipid peroxidation, reducing power, metal chelating ability and oxidative DNA damage assays. Results revealed that the antioxidant activity of β-glucan increased with the increase in irradiation dose. Irradiated β-glucan also exhibited dose dependent cancer cell growth inhibition with irradiation doses. The study revealed that low molecular weight β-glucan with enhanced antioxidant and antiproliferative activities can be produced by a simple irradiation method.

Keywords: γ-irradiation, antioxidant activity, antiproliferative activity, β-glucan, oats

Procedia PDF Downloads 457
5306 A Longitudinal Examination of the Impact of Treatment Modality on Relationship Satisfaction and Mental Health Quality of Life Outcomes among Prostate Cancer Survivors

Authors: Gabriela Ilie, Robert D. H. Rutledge

Abstract:

A review of the literature reveals a need for longitudinal studies to properly understand the quality of life of prostate cancer survivors during their prostate cancer journey in order to identify opportunities for patient support and care during prostate cancer survivorship. In this study, mental health and relationship satisfaction were assessed longitudinally and by treatment modality among a population-based sample of Canadian adult men with a history of prostate cancer diagnosis. A total of 98 men, aged 51 or older with a history of prostate cancer completed an on-line 15-minute survey between May 2017 and February 2018, assessing mental health (Kessler Psychological Distress Scale) and relationship satisfaction (Dyadic Adjustment Scale) at baseline and at three months post-treatment with either active or nonactive prostate cancer treatment. Almost 1 in 6 men in this sample screened positive for mental health issues (17.34%, n=17) irrespective of treatment modality and most (n=11) were not currently on medication for depression, anxiety or both. Mental health outcomes were poorer for men with multimorbidity. For every instance of screening positive for mental health issues, 2.021 (95% CI:1.1 to 3.8) times more comorbidities were recorded. Relationship satisfaction and dyadic cohesion were statistically significantly lower from first assessment to 3 months for men who underwent multiple treatment modalities (surgery and radiation with hormonal therapy). Relationship satisfaction was also lower at 3 months for men who underwent radiation therapy. Almost 1 in 2 men in this sample (74%) indicated they did not attend a prostate cancer support group. Results suggest that treatment for mental health is underutilized in men with prostate cancer. Men who undergo multiple forms of active treatment appear more vulnerable to relationship dissatisfaction and feeling disconnected from their partner. Data points to important opportunities for patient education and care support during survivorship.

Keywords: prostate cancer survivorship, mental health, quality of life, relationship satisfaction

Procedia PDF Downloads 117
5305 Monitoring the Railways by Means of C-OTDR Technology

Authors: Andrey V. Timofeev

Abstract:

This paper presents development results of the method of seismoacoustic activity monitoring based on usage vibrosensitive properties of optical fibers. Analysis of Rayleigh backscattering radiation parameters changes, which take place due to microscopic seismoacoustic impacts on the optical fiber, allows to determine seismoacoustic emission sources positions and to identify their types. Results of using this approach are successful for complex monitoring of railways.

Keywords: C-OTDR systems, monitoring of railways, Rayleigh backscattering, eismoacoustic activity

Procedia PDF Downloads 395
5304 Food Security of Migrants in a Regional Area of Australia: A Qualitative Study

Authors: Joanne Sin Wei Yeoh, Quynh Lê, Rosa McManamey

Abstract:

Food security indicates the ability of individuals, households and communities to acquire food that is healthy, sustainable, affordable, appropriate and accessible. Despite Australia’s current ability to produce enough food to feed a population larger than its current population, there has been substantial evidence over the last decades to demonstrate many Australians struggle to feed themselves, including those from a cultural and linguistically diverse (CALD) background. The study aimed to investigate migrants’ perceptions and experiences on food security in Tasmania. Semi-structured interviews were conducted with 33 migrants residing in North, South and North West Tasmania, who were recruited through purposive sampling. Thematic analysis was employed to analyse the interview data. Four main themes were identified from the interview data: (1) Understanding of food security; (2) Experiences with the food security in Tasmania; (3) Factors that influence migrants’ food security in Tasmania; and (4) Acculturation strategies. Various sub-themes have emerged under each of these four major themes. Though the findings indicate participants are satisfied with their current food security in Tasmania, they still encounter some challenges in food availability, accessibility, and affordability in Tasmania. Factors that influence migrants’ food security were educational background, language barrier, socioeconomic status, geographical isolation, and cultural background. By using different acculturation strategies, migrants managed to adapt to the new food culture. In addition, social and cultural capitals were also treated as vital roles in improving migrants’ food security. The findings indicate migrants residing in Tasmania face different challenges on food security. They use different strategies for food security while acculturating into a new environment. The findings may provide useful information for migrants in Australia and various private organisations or relevant government departments that address food security for migrants.

Keywords: experiences, food security, migrants, perceptions

Procedia PDF Downloads 424
5303 Intercultural Competency for Teachers at the Public Multicultural Alternative School for Immigrants and Multicultural Family Student’s School Maladjustment in Korea

Authors: Kiseob Chung, Hyeonmin Kang

Abstract:

This study aims to explore what is intercultural competency needed for teacher through their experience at the public multicultural alternative school. The public alternative multicultural school is an accredited school for immigrants or students from multicultural families who have experienced school maladjustment at public school. This school has self-regulation in curriculum and function of bridge to public school by helping their adaptation. In particular, this study answers the following questions: What are the most difficulties for teacher at the multicultural alternative school in comparison to public school? What competencies are required for teacher at the multicultural alternative school? Which competencies in cognitive, emotional and practical area should be more required in order for teacher to communicate with student effectively (successfully) in class and other activities in school? What is the background of that we called these competencies especially as ‘intercultural’? This study focuses to clarify teacher’s competency to help immigrants of students from multicultural background to adjust to school life with the term of intercultural competency.

Keywords: intercultural competency for teacher, multicultural alternative school, multicultural students, school maladjustment

Procedia PDF Downloads 466
5302 Sustainable Development of Adsorption Solar Cooling Machine

Authors: N. Allouache, W. Elgahri, A. Gahfif, M. Belmedani

Abstract:

Solar radiation is by far the largest and the most world’s abundant, clean and permanent energy source. The amount of solar radiation intercepted by the Earth is much higher than annual global energy use. The energy available from the sun is greater than about 5200 times the global world’s need in 2006. In recent years, many promising technologies have been developed to harness the sun's energy. These technologies help in environmental protection, economizing energy, and sustainable development, which are the major issues of the world in the 21st century. One of these important technologies is the solar cooling systems that make use of either absorption or adsorption technologies. The solar adsorption cooling systems are a good alternative since they operate with environmentally benign refrigerants that are natural, free from CFCs, and therefore they have a zero ozone depleting potential (ODP). A numerical analysis of thermal and solar performances of an adsorption solar refrigerating system using different adsorbent/adsorbate pairs, such as activated carbon AC35 and activated carbon BPL/Ammoniac; is undertaken in this study. The modeling of the adsorption cooling machine requires the resolution of the equation describing the energy and mass transfer in the tubular adsorber, that is the most important component of the machine. The Wilson and Dubinin- Astakhov models of the solid-adsorbat equilibrium are used to calculate the adsorbed quantity. The porous medium is contained in the annular space, and the adsorber is heated by solar energy. Effect of key parameters on the adsorbed quantity and on the thermal and solar performances are analysed and discussed. The performances of the system that depends on the incident global irradiance during a whole day depends on the weather conditions: the condenser temperature and the evaporator temperature. The AC35/methanol pair is the best pair comparing to the BPL/Ammoniac in terms of system performances.

Keywords: activated carbon-methanol pair, activated carbon-ammoniac pair, adsorption, performance coefficients, numerical analysis, solar cooling system

Procedia PDF Downloads 78
5301 Magnetohemodynamic of Blood Flow Having Impact of Radiative Flux Due to Infrared Magnetic Hyperthermia: Spectral Relaxation Approach

Authors: Ebenezer O. Ige, Funmilayo H. Oyelami, Joshua Olutayo-Irheren, Joseph T. Okunlola

Abstract:

Hyperthermia therapy is an adjuvant procedure during which perfused body tissues is subjected to elevated range of temperature in bid to achieve improved drug potency and efficacy of cancer treatment. While a selected class of hyperthermia techniques is shouldered on the thermal radiations derived from single-sourced electro-radiation measures, there are deliberations on conjugating dual radiation field sources in an attempt to improve the delivery of therapy procedure. This paper numerically explores the thermal effectiveness of combined infrared hyperemia having nanoparticle recirculation in the vicinity of imposed magnetic field on subcutaneous strata of a model lesion as ablation scheme. An elaborate Spectral relaxation method (SRM) was formulated to handle equation of coupled momentum and thermal equilibrium in the blood-perfused tissue domain of a spongy fibrous tissue. Thermal diffusion regimes in the presence of external magnetic field imposition were described leveraging on the renowned Roseland diffusion approximation to delineate the impact of radiative flux within the computational domain. The contribution of tissue sponginess was examined using mechanics of pore-scale porosity over a selected of clinical informed scenarios. Our observations showed for a substantial depth of spongy lesion, magnetic field architecture constitute the control regimes of hemodynamics in the blood-tissue interface while facilitating thermal transport across the depth of the model lesion. This parameter-indicator could be utilized to control the dispensing of hyperthermia treatment in intravenous perfused tissue.

Keywords: spectra relaxation scheme, thermal equilibrium, Roseland diffusion approximation, hyperthermia therapy

Procedia PDF Downloads 118
5300 Statistical Characteristics of Distribution of Radiation-Induced Defects under Random Generation

Authors: P. Selyshchev

Abstract:

We consider fluctuations of defects density taking into account their interaction. Stochastic field of displacement generation rate gives random defect distribution. We determinate statistical characteristics (mean and dispersion) of random field of point defect distribution as function of defect generation parameters, temperature and properties of irradiated crystal.

Keywords: irradiation, primary defects, interaction, fluctuations

Procedia PDF Downloads 343
5299 PTOP Expression Correlates with Telomerase Activity and Grades of Malignancy in Human Glioma Tissues

Authors: F. Polito, M. Cucinotta, A. Conti, C. Lo Giudice, C. Tomasello, F. Angileri, D. La Torre, M. Aguennouz

Abstract:

Glioblastoma multiforme (GBM) is the most aggressive form of brain tumors, with an extremely poor prognosis. Telomeres lenght is associated with tumor progression in several type of human cancers and telomere elongation is a common molecular feature of advanced malignancies. Among the telomeric shelterin proteins PTOP is required for telomeric protein complex assembly, telomerase recruitment and activity, and telomere length regulation through a PTOP-telomerase interaction. Previous studies suggest that PTOP upregulation is involved in radioresistance and telomere lengthening in colorectal cancer cells. Moreover, in human osteosarcoma cells PTOP deletion led to telomere shortening, increased apoptosis and radiation sensitivity enhancement. However, to date, little is known about the role of PTOP in progression of glioma cancers. In light of this background aim of the study is to investigate the expression of PTOP in different grades of human glioma and its correlation with the pathological grade of gliomas, grades of malignancy, proliferative activity and apoptosis. Fifteen Low Grade Astrocytomas (LGA), 18 Anaplastic Astrocytomas (AA) and 26 Glioblastoma Multiforme (GBM) samples were analyzed. Three samples of normal brain tissue (NBT) were used as controls. The expression levels of PTOP, h-TERT, BIRC1 and cyclin D1 were determined by real time PCR and/or western blot. Results obtained shows that PTOP expression in glioma tissues is tightly correlated with clinical grade ( p < 0.01 ). No correlation was found between PTOP expression and other clinicopathologic parameters. The expression of PTOP was positively correlated with the expression of hTERT and TERF1. Furthermore PTOP positively correlates with cyclin D1 and negatively correlates with the expression of BIRC1. Our findings indicate that PTOP might play key role in the progression of glioma regulating telomerase activity and likely through regulation of cell cycle and apoptosis. In conclusion results obtained prompted us to speculate that PTOP might represents a potential molecular bio marker and a therapeutic target for the treatment of glioblastoma tumors.

Keywords: glioblastoma, PTOP, telomere, brain tumors

Procedia PDF Downloads 346
5298 Mid-Winter Stratospheric Warming Effects on Equatorial Dynamics over Peninsular India

Authors: SHWETA SRIKUMAR

Abstract:

Winter stratospheric dynamics is a highly variable and spectacular field of research in middle atmosphere. It is well believed that the interaction of energetic planetary waves with mean flow causes the temperature to increase in the stratosphere and associated circulation reversal. This wave driven sudden disturbances in the polar stratosphere is defined as Sudden Stratospheric Warming. The main objective of the present work is to investigate the mid-winter major stratospheric warming events on equatorial dynamics over Peninsular India. To explore the effect of mid-winter stratospheric warming on Indian region (60oE -100oE), we have selected the winters 2003/04, 2005/06, 2008/09, 2012/13 and 2018/19. This study utilized the data from ERA-Interim Reanalysis, Outgoing Longwave Radiation (OLR) from NOAA and TRMM satellite data from NASA mission. It is observed that a sudden drop in OLR (averaged over Indian Region) occurs during the course of warming for the winters 2005/06, 2008/09 and 2018/19. But in winters 2003/04 and 2012/13, drop in OLR happens prior to the onset of major warming. Significant amplitude of planetary wave activity is observed in equatorial lower stratosphere which indicates the propagation of extra-tropical planetary waves from high latitude to equator. During the course of warming, a strong downward propagation of EP flux convergence is observed from polar to equator region. The polar westward wind reaches upto 20oN and the weak eastward wind dominates the equator during the winters 2003/04, 2005/06 and 2018/19. But in 2012/13 winter, polar westward wind reaches upto equator. The equatorial wind at 2008/09 is dominated by strong westward wind. Further detailed results will be presented in the conference.

Keywords: Equatorial dynamics, Outgoing Longwave Radiation, Sudden Stratospheric Warming, Planetary Waves

Procedia PDF Downloads 143
5297 Application of Electrochromic Glazing for Reducing Peak Cooling Loads

Authors: Ranojoy Dutta

Abstract:

HVAC equipment capacity has a direct impact on occupant comfort and energy consumption of a building. Glazing gains, especially in buildings with high window area, can be a significant contributor to the total peak load on the HVAC system, leading to over-sized systems that mostly operate at poor part load efficiency. In addition, radiant temperature, which largely drives occupant comfort in glazed perimeter zones, is often not effectively controlled despite the HVAC being designed to meet the air temperature set-point. This is due to short wave solar radiation transmitted through windows, that is not sensed by the thermostat until much later when the thermal mass in the room releases the absorbed solar heat to the indoor air. The implication of this phenomenon is increased cooling energy despite poor occupant comfort. EC glazing can significantly eliminate direct solar transmission through windows, reducing both the space cooling loads for the building and improving comfort for occupants near glazing. This paper will review the exact mechanism of how EC glazing would reduce the peak load under design day conditions, leading to reduced cooling capacity vs regular high-performance glazing. Since glazing heat transfer only affects the sensible load, system sizing will be evaluated both with and without the availability of a DOAS to isolate the downsizing potential of the primary cooling equipment when outdoor air is conditioned separately. Given the dynamic nature of glazing gains due to the sun’s movement, effective peak load mitigation with EC requires an automated control system that can predict solar movement and radiation levels so that the right tint state with the appropriate SHGC is utilized at any given time for a given façade orientation. Such an automated EC product will be evaluated for a prototype commercial office model situated in four distinct climate zones.

Keywords: electrochromic glazing, peak sizing, thermal comfort, glazing load

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5296 Youth and Radicalization: Main Causes Who Lead Young People to Radicalize in a Context with Background of Radicalization

Authors: Zineb Emrane

Abstract:

This abstract addresses the issue of radicalization of young people in a context with background of radicalization, in North of Morocco, 5 terrorist of Madrid's Attacts on 11th March, were coming from this context. It were developed a study pilot that describing young people perception about the main causes that lead and motivate for radicalization. Whenever we talk about this topic, we obtain information from studies and investigations by specialists in field, but we don’t give voice to the protagonists who in many cases are victims, specifically, young people at social risk because of social factors. Extremist radicalization is an expanding phenomenon, that affect young people, in north of Morocco. They live in a context with radical background and at risk of social exclusion, their social, economic and familiar needs make them vulnerable. The extremist groups take advantage of this vulnerability to involve them in a process of radicalization, offering them an alternative environment where they can found all they are looking for. This study pilot approaches the main causes that lead and motivates young people to become radicals, analyzing their context with emphasis on influencing factors, and bearing in mind the analysis of young people about how the radical background affect them and their opinion this phenomenon. The pilot study was carried out through the following actions: - Group dynamics with young people to analyze the process of violent radicalization of young people. -A participatory workshop with members of organizations that work directly with young people at risk of radicalization. -Interviews with institutional managers -Participant observation. The implementation of actions has led to the conclusion that young people define violent radicalization as a sequential process, depending on the stage, it can be deconstructed. Young people recognize that they stop feeling belonging to their family, school and neighborhood when they see behavior contrary to what they consider good and evil. The emotional rupture and the search for references outside their circle, push them to sympathize with groups that have an extremist ideology and that offer them what they need. The radicalization is a process with different stages, the main causes and the factors which lead young people to use extremist violence are related their low level of belonging feeling to their context, and lack of critical thinking about important issues. The young people are in a vulnerable stage, searching their identity, a space in which they can be accepted, and when they don't find it they are easily manipulated and susceptible to being attracted by extremist groups.

Keywords: exclusion, radicalization, vulnerability, youth

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5295 Application of Homer Optimization to Investigate the Prospects of Hybrid Renewable Energy System in Rural Area: Case of Rwanda

Authors: Emile Niringiyimana, LI Ji Qing, Giovanni Dushimimana, Virginie Umwere

Abstract:

The development and utilization of renewable energy (RE) can not only effectively reduce carbon dioxide (CO2) emissions, but also became a solution to electricity shortage mitigation in rural areas. Hybrid RE systems are promising ways to provide consistent and continuous power for isolated areas. This work investigated the prospect and cost effectiveness of hybrid system complementarity between a 100kW solar PV system and a small-scale 200kW hydropower station in the South of Rwanda. In order to establish the optimal size of a RE system with adequate sizing of system components, electricity demand, solar radiation, hydrology, climate data are utilized as system input. The average daily solar radiation in Rukarara is 5.6 kWh/m2 and average wind speed is 3.5 m/s. The ideal integrated RE system, according to Homer optimization, consists of 91.21kW PV, 146kW hydropower, 12 x 24V li-ion batteries with a 20kW converter. The method of enhancing such hybrid systems control, sizing and choice of components is to reduce the Net present cost (NPC) of the system, unmet load, the cost of energy and reduction of CO2. The power consumption varies according to dominant source of energy in the system by controlling the energy compensation depending on the generation capacity of each power source. The initial investment of the RE system is $977,689.25, and its operation and maintenance expenses is $142,769.39 over a 25-year period. Although the investment is very high, the targeted profits in future are huge, taking into consideration of high investment in rural electrification structure implementations, tied with an increase of electricity cost and the 5 years payback period. The study outcomes suggest that the standalone hybrid PV-Hydropower system is feasible with zero pollution in Rukara community.

Keywords: HOMER optimization, hybrid power system, renewable energy, NPC and solar pv systems

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5294 Feasibility of Voluntary Deep Inspiration Breath-Hold Radiotherapy Technique Implementation without Deep Inspiration Breath-Hold-Assisting Device

Authors: Auwal Abubakar, Shazril Imran Shaukat, Noor Khairiah A. Karim, Mohammed Zakir Kassim, Gokula Kumar Appalanaido, Hafiz Mohd Zin

Abstract:

Background: Voluntary deep inspiration breath-hold radiotherapy (vDIBH-RT) is an effective cardiac dose reduction technique during left breast radiotherapy. This study aimed to assess the accuracy of the implementation of the vDIBH technique among left breast cancer patients without the use of a special device such as a surface-guided imaging system. Methods: The vDIBH-RT technique was implemented among thirteen (13) left breast cancer patients at the Advanced Medical and Dental Institute (AMDI), Universiti Sains Malaysia. Breath-hold monitoring was performed based on breath-hold skin marks and laser light congruence observed on zoomed CCTV images from the control console during each delivery. The initial setup was verified using cone beam computed tomography (CBCT) during breath-hold. Each field was delivered using multiple beam segments to allow a delivery time of 20 seconds, which can be tolerated by patients in breath-hold. The data were analysed using an in-house developed MATLAB algorithm. PTV margin was computed based on van Herk's margin recipe. Results: The setup error analysed from CBCT shows that the population systematic error in lateral (x), longitudinal (y), and vertical (z) axes was 2.28 mm, 3.35 mm, and 3.10 mm, respectively. Based on the CBCT image guidance, the Planning target volume (PTV) margin that would be required for vDIBH-RT using CCTV/Laser monitoring technique is 7.77 mm, 10.85 mm, and 10.93 mm in x, y, and z axes, respectively. Conclusion: It is feasible to safely implement vDIBH-RT among left breast cancer patients without special equipment. The breath-hold monitoring technique is cost-effective, radiation-free, easy to implement, and allows real-time breath-hold monitoring.

Keywords: vDIBH, cone beam computed tomography, radiotherapy, left breast cancer

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5293 Optimized Passive Heating for Multifamily Dwellings

Authors: Joseph Bostick

Abstract:

A method of decreasing the heating load of HVAC systems in a single-dwelling model of a multifamily building, by controlling movable insulation through the optimization of flux, time, surface incident solar radiation, and temperature thresholds. Simulations are completed using a co-simulation between EnergyPlus and MATLAB as an optimization tool to find optimal control thresholds. Optimization of the control thresholds leads to a significant decrease in total heating energy expenditure.

Keywords: energy plus, MATLAB, simulation, energy efficiency

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5292 Characterizing Nanoparticles Generated from the Different Working Type and the Stack Flue during 3D Printing Process

Authors: Kai-Jui Kou, Tzu-Ling Shen, Ying-Fang Wang

Abstract:

The objectives of the present study are to characterize nanoparticles generated from the different working type in 3D printing room and the stack flue during 3D printing process. The studied laboratory (10.5 m× 7.2 m × 3.2 m) with a ventilation rate of 500 m³/H is installed a 3D metal printing machine. Direct-reading instrument of a scanning mobility particle sizer (SMPS, Model 3082, TSI Inc., St. Paul, MN, USA) was used to conduct static sampling for nanoparticle number concentration and particle size distribution measurements. The SMPS obtained particle number concentration at every 3 minutes, the diameter of the SMPS ranged from 11~372 nm when the aerosol and sheath flow rates were set at 0.6 and 6 L/min, respectively. The concentrations of background, printing process, clearing operation, and screening operation were performed in the laboratory. On the other hand, we also conducted nanoparticle measurement on the 3D printing machine's stack flue to understand its emission characteristics. Results show that the nanoparticles emitted from the different operation process were the same distribution in the form of the uni-modal with number median diameter (NMD) as approximately 28.3 nm to 29.6 nm. The number concentrations of nanoparticles were 2.55×10³ count/cm³ in laboratory background, 2.19×10³ count/cm³ during printing process, 2.29×10³ count/cm³ during clearing process, 3.05×10³ count/cm³ during screening process, 2.69×10³ count/cm³ in laboratory background after printing process, and 6.75×10³ outside laboratory, respectively. We found that there are no emission nanoparticles during the printing process. However, the number concentration of stack flue nanoparticles in the ongoing print is 1.13×10⁶ count/cm³, and that of the non-printing is 1.63×10⁴ count/cm³, with a NMD of 458 nm and 29.4 nm, respectively. It can be confirmed that the measured particle size belongs to easily penetrate the filter in theory during the printing process, even though the 3D printer has a high-efficiency filtration device. Therefore, it is recommended that the stack flue of the 3D printer would be equipped with an appropriate dust collection device to prevent the operators from exposing these hazardous particles.

Keywords: nanoparticle, particle emission, 3D printing, number concentration

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5291 Personal Identity and Group Identity under Threat following Exclusion: A Study in Singapore and in the Netherlands

Authors: Z. N. Huwaë, E.M. W. Tong, Y. H. M. See

Abstract:

In the present study, the researchers examined whether people from collectivistic cultures perceive a more group identity threat following social exclusion, whereas a more personal identity threat would be the case for those from individualistic cultures. In doing so, they investigated whether threatened identities depend on whether people are excluded by ingroup members (same ethnic background) or outgroup members (another ethnic background), as exclusion studies have shown mixed results when it comes to being excluded by ingroup versus outgroup members. For this purpose, students in Singapore and in the Netherlands participated in an online ball-tossing game (Cyberball) where they were excluded or included by other players with either the same or other ethnicity. Tentative results showed that both Singaporean and Dutch participants reported a more threat to their group identity than to their personal identity following exclusion and this did not depend on who excluded them. These tentative findings suggest that threatened identities following exclusion may not depend on cultural factors or on the source of exclusion.

Keywords: cultures, exclusion, experiment, group membership, identities

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5290 Applying the Eye Tracking Technique for the Evaluation of Oculomotor System in Patients Survived after Cerebellar Tumors

Authors: Marina Shurupova, Victor Anisimov, Alexander Latanov

Abstract:

Background: The cerebellar lesions inevitably provoke oculomotor impairments in patients of different age. Symptoms of subtentorial tumors, particularly medulloblastomas, include static and dynamic coordination disorders (ataxia, asynergia, imbalance), hypo-muscle tonus, disruption of the cranial nerves, and within the oculomotor system - nystagmus (fine or gross). Subtentorial tumors can also affect the areas of cerebellum that control the oculomotor system. The noninvasive eye-tracking technology allows obtaining multiple oculomotor characteristics such as the number of fixations and their duration, amplitude, latency and velocity of saccades, trajectory and scan path of gaze during the process of the visual field navigation. Eye tracking could be very useful in clinical studies serving as convenient and effective tool for diagnostics. The aim: We studied the dynamics of oculomotor system functioning in patients undergoing remission from cerebellar tumors removal surgeries and following neurocognitive rehabilitation. Methods: 38 children (23 boys, 15 girls, 9-17 years old) that have recovered from the cerebellar tumor-removal surgeries, radiation therapy and chemotherapy and were undergoing course of neurocognitive rehabilitation participated in the study. Two tests were carried out to evaluate oculomotor performance - gaze stability test and counting test. The monocular eye movements were recorded with eye tracker ArringtonResearch (60 Hz). Two experimental sessions with both tests were conducted before and after rehabilitation courses. Results: Within the final session of both tests we observed remarkable improvement in oculomotor performance: 1) in the gaze stability test the spread of gaze positions significantly declined compared to the first session, and 2) the visual path in counting test significantly shortened both compared to the first session. Thus, neurocognitive rehabilitation improved the functioning of the oculomotor system in patients following the cerebellar tumor removal surgeries and subsequent therapy. Conclusions: The experimental data support the effectiveness of the utilization of the eye tracking technique as diagnostic tool in the field of neurooncology.

Keywords: eye tracking, rehabilitation, cerebellar tumors, oculomotor system

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5289 Effect of the Support Shape on Fischer-Tropsch Cobalt Catalyst Performance

Authors: Jian Huang, Weixin Qian, Hongfang Ma, Haitao Zhang, Weiyong Ying

Abstract:

Cobalt catalysts were supported on extruded silica carrier and different-type (SiO2, γ-Al2O3) commercial supports with different shapes and sizes to produce heavy hydrocarbons for Fischer-Tropsch synthesis. The catalysts were characterized by N2 physisorption and H2-TPR. The catalytic performance of the catalysts was tested in a fixed bed reactor. The results of Fischer-Tropsch synthesis performance showed that the cobalt catalyst supported on spherical silica supports displayed a higher activity and a higher selectivity to C5+ products, due to the fact that the active components were only distributed in the surface layer of spherical carrier, and the influence of gas diffusion restriction on catalytic performance was weakened. Therefore, it can be concluded that the eggshell cobalt catalyst was superior to precious metals modified catalysts in the synthesis of heavy hydrocarbons.

Keywords: fischer-tropsch synthesis, cobalt catalyst, support shape, heavy hydrocarbons

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