Search results for: star formation rate
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 10923

Search results for: star formation rate

6063 Numerical Investigation of Solid Subcooling on a Low Melting Point Metal in Latent Thermal Energy Storage Systems Based on Flat Slab Configuration

Authors: Cleyton S. Stampa

Abstract:

This paper addresses the perspectives of using low melting point metals (LMPMs) as phase change materials (PCMs) in latent thermal energy storage (LTES) units, through a numerical approach. This is a new class of PCMs that has been one of the most prospective alternatives to be considered in LTES, due to these materials present high thermal conductivity and elevated heat of fusion, per unit volume. The chosen type of LTES consists of several horizontal parallel slabs filled with PCM. The heat transfer fluid (HTF) circulates through the channel formed between each two consecutive slabs on a laminar regime through forced convection. The study deals with the LTES charging process (heat-storing) by using pure gallium as PCM, and it considers heat conduction in the solid phase during melting driven by natural convection in the melt. The transient heat transfer problem is analyzed in one arbitrary slab under the influence of the HTF. The mathematical model to simulate the isothermal phase change is based on a volume-averaged enthalpy method, which is successfully verified by comparing its predictions with experimental data from works available in the pertinent literature. Regarding the convective heat transfer problem in the HTF, it is assumed that the flow is thermally developing, whereas the velocity profile is already fully developed. The study aims to learn about the effect of the solid subcooling in the melting rate through comparisons with the melting process of the solid in which it starts to melt from its fusion temperature. In order to best understand this effect in a metallic compound, as it is the case of pure gallium, the study also evaluates under the same conditions established for the gallium, the melting process of commercial paraffin wax (organic compound) and of the calcium chloride hexahydrate (CaCl₂ 6H₂O-inorganic compound). In the present work, it is adopted the best options that have been established by several researchers in their parametric studies with respect to this type of LTES, which lead to high values of thermal efficiency. To do so, concerning with the geometric aspects, one considers a gap of the channel formed by two consecutive slabs, thickness and length of the slab. About the HTF, one considers the type of fluid, the mass flow rate, and inlet temperature.

Keywords: flat slab, heat storing, pure metal, solid subcooling

Procedia PDF Downloads 129
6062 Spatial-Temporal Characteristics of Bacterioplankton in the Upper Part of Taktakorpu Water Complex

Authors: Fidan Z. Aliyeva

Abstract:

In the presented article, the formation of the microbiological regime in the Takhtakorpu water complex, as well as spatial-temporal changes in the quantitative indicators of bacterioplankton, were studied. Taktakorpu water complex was built as a continuation of the reconstruction and expansion project of the Samur-Absheron irrigation system in Shabran on the northeastern slope of our republic. It should be noted that with the implementation of the project, the water supply of up to 150 thousand ha of useful land in the northern region has been improved, and the drinking, technical, and irrigation water needs of the population of Baku, Sumgayit and also the Absheron Peninsula, and industrial and agricultural areas, joining the agricultural circulation of new soil areas, Takhtakorpu reservoir with a volume of 238.4 million m³, connected with them -Valvalachay- Takhtakorpu and Takhtakorpu-Jeyranbatan canals have been created, conditions have been created to increase the resources of the Jeyranbatan reservoir. Special attention is paid to the study of saprophytic bacteria in order to determine the development dynamics and biochemical activity of the microbiological regime in the Takhtakorpu Water Complex, which is of great strategic importance for our republic, to evaluate changes under the influence of anthropogenic factors, as well as to evaluate the properties of self-cleaning, mineralization features of organic substances of allochthon and autochthonous origin. One of the main goals of our research is to determine the main structural indicators of bacterioplankton in the upper part of Takhtakorpu water complex in the first three stations and analyzing their quantitative values in a certain time aspect.

Keywords: water, irrigation, sewage, wastewater

Procedia PDF Downloads 60
6061 Synthesis of Amine Functionalized MOF-74 for Carbon Dioxide Capture

Authors: Ghulam Murshid, Samil Ullah

Abstract:

Scientific studies suggested that the incremented greenhouse gas concentration in the atmosphere, particularly of carbon dioxide (CO2) is one of the major factors in global warming. The concentration of CO2 in our climate has crossed the milestone level of 400 parts per million (ppm) hence breaking the record of human history. A report by 49 researchers from 10 countries said, 'Global CO2 emissions from burning fossil fuels will rise to a record 36 billion metric tons (39.683 billion tons) this year.' Main contributors of CO2 in to the atmosphere are usage of fossil fuel, transportation sector and power generation plants. Among all available technologies, which include; absorption via chemicals, membrane separation, cryogenic and adsorption are in practice around the globe. Adsorption of CO2 using metal organic frameworks (MOF) is getting interest of researcher around the globe. In the current work, MOF-74 as well as modified MOF-74 with a sterically hindered amine (AMP) was synthesized and characterized. The modification was carried out using a sterically hindered amine in order to study the effect on its adsorption capacity. Resulting samples were characterized by using Fourier Transform Infrared Spectroscopy (FTIR), Field Emission Scanning Electron Microscope (FESEM), Thermal Gravimetric Analyser (TGA) and Brunauer-Emmett-Teller (BET). The FTIR results clearly confirmed the formation of MOF-74 structure and the presence of AMP. FESEM and TEM revealed the topography and morphology of the both MOF-74 and amine modified MOF. BET isotherm result shows that due to the addition of AMP in to the structure, significant enhancement of CO2 adsorption was observed.

Keywords: adsorbents, amine, CO2, global warming

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6060 Q-Learning of Bee-Like Robots Through Obstacle Avoidance

Authors: Jawairia Rasheed

Abstract:

Modern robots are often used for search and rescue purpose. One of the key areas of interest in such cases is learning complex environments. One of the key methodologies for robots in such cases is reinforcement learning. In reinforcement learning robots learn to move the path to reach the goal while avoiding obstacles. Q-learning, one of the most advancement of reinforcement learning is used for making the robots to learn the path. Robots learn by interacting with the environment to reach the goal. In this paper simulation model of bee-like robots is implemented in NETLOGO. In the start the learning rate was less and it increased with the passage of time. The bees successfully learned to reach the goal while avoiding obstacles through Q-learning technique.

Keywords: reinforlearning of bee like robots for reaching the goalcement learning for randomly placed obstacles, obstacle avoidance through q-learning, q-learning for obstacle avoidance,

Procedia PDF Downloads 78
6059 Synthesis and Characterization of an Aerogel Based on Graphene Oxide and Polyethylene Glycol

Authors: Javiera Poblete, Fernando Gajardo, Katherina Fernandez

Abstract:

Graphene, and its derivatives such as graphene oxide (GO), are emerging nanoscopic materials, with interesting physical and chemical properties. From them, it is possible to develop three-dimensional macrostructures, such as aerogels, which are characterized by a low density, high porosity, and large surface area, having a promising structure for the development of materials. The use of GO as a precursor of these structures provides a wide variety of materials, which can be developed as a result of the functionalization of their oxygenated groups, with specific compounds such as polyethylene glycol (PEG). The synthesis of aerogels of GO-PEG for non-covalent interactions has not yet been widely reported, being of interest due to its feasible escalation and economic viability. Thus, this work aims to develop a non-covalently functionalized GO-PEG aerogels and characterize them physicochemically. In order to get this, the GO was synthesized from the modified hummers method and it was functionalized with the PEG by polymer-assisted GO gelation (crosslinker). The gelation was obtained for GO solutions (10 mg/mL) with the incorporation of PEG in different proportions by weight. The hydrogel resulting from the reaction was subsequently lyophilized, to obtain the respective aerogel. The material obtained was chemically characterized by analysis of Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy and X-ray diffraction (XRD), and its morphology by scanning electron microscopy (SEM) images; as well as water absorption tests. The results obtained showed the formation of a non-covalent aerogel (FTIR), whose structure was highly porous (SEM) and with a water absorption values greater than 50% g/g. Thus, a methodology of synthesis for GO-PEG was developed and validated.

Keywords: aerogel, graphene oxide, polyethylene glycol, synthesis

Procedia PDF Downloads 106
6058 Economic Efficiency of Cassava Production in Nimba County, Liberia: An Output-Oriented Approach

Authors: Kollie B. Dogba, Willis Oluoch-Kosura, Chepchumba Chumo

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In Liberia, many of the agricultural households cultivate cassava for either sustenance purposes, or to generate farm income. Many of the concentrated cassava farmers reside in Nimba, a north-eastern County that borders two other economies: the Republics of Cote D’Ivoire and Guinea. With a high demand for cassava output and products in emerging Asian markets coupled with an objective of the Liberia agriculture policies to increase the competitiveness of valued agriculture crops; there is a need to examine the level of resource-use efficiency for many agriculture crops. However, there is a scarcity of information on the efficiency of many agriculture crops, including cassava. Hence the study applying an output-oriented method seeks to assess the economic efficiency of cassava farmers in Nimba County, Liberia. A multi-stage sampling technique was employed to generate a sample for the study. From 216 cassava farmers, data related to on-farm attributes, socio-economic and institutional factors were collected. The stochastic frontier models, using the Translog functional forms, of production and revenue, were used to determine the level of revenue efficiency and its determinants. The result showed that most of the cassava farmers are male (60%). Many of the farmers are either married, engaged or living together with a spouse (83%), with a mean household size of nine persons. Farmland is prevalently obtained by inheritance (95%), average farm size is 1.34 hectares, and most cassava farmers did not access agriculture credits (76%) and extension services (91%). The mean cassava output per hectare is 1,506.02 kg, which estimates average revenue of L$23,551.16 (Liberian dollars). Empirical results showed that the revenue efficiency of cassava farmers varies from 0.1% to 73.5%; with the mean revenue efficiency of 12.9%. This indicates that on average, there is a vast potential of 87.1% to increase the economic efficiency of cassava farmers in Nimba by improving technical and allocative efficiencies. For the significant determinants of revenue efficiency, age and group membership had negative effects on revenue efficiency of cassava production; while farming experience, access to extension, formal education, and average wage rate have positive effects. The study recommends the setting-up and incentivizing of farmer field schools for cassava farmers to primarily share their farming experiences with others and to learn robust cultivation techniques of sustainable agriculture. Also, farm managers and farmers should consider a fix wage rate in labor contracts for all stages of cassava farming.

Keywords: economic efficiency, frontier production and revenue functions, Nimba County, Liberia, output-oriented approach, revenue efficiency, sustainable agriculture

Procedia PDF Downloads 114
6057 Ultrasonic Investigation as Tool for Study of Molecular Interaction of 2-Hydroxy Substituted Pyrimidine Derivative at Different Concentrations

Authors: Shradha S. Binani, P. S. Bodke, R. V. Joat

Abstract:

Recent decades have witnessed an exponential growth in the field of acoustical parameters and ultrasound on solid, liquid and gases. Ultrasonic propagation parameters yield valuable information regarding the behavior of liquid systems because intra and intermolecular association, dipolar interaction, complex formation and related structural changes affecting the compressibility of the system which in turn produces variations in the ultrasonic velocity. The acoustic and thermo dynamical parameters obtained in ultrasonic study show that ion-solvation is accompanied by the destruction or enhancement of the solvent structure. In the present paper the ultrasonic velocity (v), density (ρ), viscosity(η) have been measured for the pharmacological important compound 2-hydroxy substituted phenyl pyrimidine derivative (2-hydroxy-4-(4’-methoxy phenyl)-6-(2’-hydroxy-4’-methyl-5’-chlorophenyl)pyrimidine) in ethanol as a solvent by using different concentration at constant room temperature. These experimental data have been used to estimate physical parameter like adiabatic compressibility, intermolecular free length, relaxation time, free volume, specific acoustic impedance, relative association, Wada’s constant, Rao’s constant etc. The above parameters provide information in understanding the structural and molecular interaction between solute-solvent in the drug solution with respect to change in concentration.

Keywords: acoustical parameters, ultrasonic velocity, density, viscosity, 2-hydroxy substituted phenyl pyrimidine derivative

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6056 Enhancement of coupler-based delay line filters modulation techniques using optical wireless channel and amplifiers at 100 Gbit/s

Authors: Divya Sisodiya, Deepika Sipal

Abstract:

Optical wireless communication (OWC) is a relatively new technology in optical communication systems that allows for high-speed wireless optical communication. This research focuses on developing a cost-effective OWC system using a hybrid configuration of optical amplifiers. In addition to using EDFA amplifiers, a comparison study was conducted to determine which modulation technique is more effective for communication. This research examines the performance of an OWC system based on ASK and PSK modulation techniques by varying OWC parameters under various atmospheric conditions such as rain, mist, haze, and snow. Finally, the simulation results are discussed and analyzed.

Keywords: OWC, bit error rate, amplitude shift keying, phase shift keying, attenuation, amplifiers

Procedia PDF Downloads 118
6055 Inpatient Drug Related Problems and Pharmacist Intervention at a Tertiary Care Teaching Hospital in South India: A Retrospective Study

Authors: Bollu Mounica

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Background: Nowadays drug related problems were seen very commonly within the health care practice. These could result in the medication errors, adverse events, drug interactions and harm to patients. Pharmacist has an identified role in minimizing and preventing such type of problems. Objectives: To detect the incidence of drug related problems for the hospitalized patient, and to analyze the clinical pharmacist interventions performed during the review of prescription orders of the general medicine, psychiatry, surgery, pediatrics, gynaecology units of a large tertiary care teaching hospital. Methods: It was a retrospective, observational and interventional study. The analysis took place daily with the following parameters: dose, rate of administration, presentation and/or dosage form, presence of inappropriate/unnecessary drugs, necessity of additional medication, more proper alternative therapies, presence of relevant drug interactions, inconsistencies in prescription orders, physical-chemical incompatibilities/solution stability. From this evaluation, the drug therapy problems were classified, as well as the resulting clinical interventions. For a period starting November 2012 until December 2014, the inpatient medication charts and orders were identified and rectified by ward and practicing clinical pharmacists within the inpatient pharmacy services in a tertiary care teaching hospital on routine daily activities. Data was collected and evaluated. The causes of this problem were identified. Results: A total of 360 patients were followed. Male (71.66%) predominance was noted over females (28.33%). Drug related problems were more commonly seen in patients aged in between 31-60. Most of the DRP observed in the study resulted from the dispensing errors (26.11%), improper drug selection (17.22%), followed by untreated indications (14.4%) Majority of the clinical pharmacist recommendations were on need for proper dispensing (26.11%), and drug change (18.05%). Minor significance of DRPs were noted high (41.11 %), whereas (35.27 %) were moderate and (23.61 %) were major. The acceptance rate of intervening clinical pharmacist recommendation and change in drug therapy was found to be high (86.66%). Conclusion: Our study showed that the prescriptions reviewed had some drug therapy problem and the pharmacist interventions have promoted positive changes needed in the prescriptions. In this context, routine participation of clinical pharmacists in clinical medical rounds facilitates the identification of DRPs and may prevent their occurrence.

Keywords: drug related problems, clinical pharmacist, drug prescriptions, drug related problems, intervention

Procedia PDF Downloads 293
6054 Development of a Multi-Variate Model for Matching Plant Nitrogen Requirements with Supply for Reducing Losses in Dairy Systems

Authors: Iris Vogeler, Rogerio Cichota, Armin Werner

Abstract:

Dairy farms are under pressure to increase productivity while reducing environmental impacts. Effective fertiliser management practices are critical to achieve this. Determination of optimum nitrogen (N) fertilisation rates which maximise pasture growth and minimise N losses is challenging due to variability in plant requirements and likely near-future supply of N by the soil. Remote sensing can be used for mapping N nutrition status of plants and to rapidly assess the spatial variability within a field. An algorithm is, however, lacking which relates the N status of the plants to the expected yield response to additions of N. The aim of this simulation study was to develop a multi-variate model for determining N fertilisation rate for a target percentage of the maximum achievable yield based on the pasture N concentration (ii) use of an algorithm for guiding fertilisation rates, and (iii) evaluation of the model regarding pasture yield and N losses, including N leaching, denitrification and volatilisation. A simulation study was carried out using the Agricultural Production Systems Simulator (APSIM). The simulations were done for an irrigated ryegrass pasture in the Canterbury region of New Zealand. A multi-variate model was developed and used to determine monthly required N fertilisation rates based on pasture N content prior to fertilisation and targets of 50, 75, 90 and 100% of the potential monthly yield. These monthly optimised fertilisation rules were evaluated by running APSIM for a ten-year period to provide yield and N loss estimates from both nonurine and urine affected areas. Comparison with typical fertilisation rates of 150 and 400 kg N/ha/year was also done. Assessment of pasture yield and leaching from fertiliser and urine patches indicated a large reduction in N losses when N fertilisation rates were controlled by the multi-variate model. However, the reduction in leaching losses was much smaller when taking into account the effects of urine patches. The proposed approach based on biophysical modelling to develop a multi-variate model for determining optimum N fertilisation rates dependent on pasture N content is very promising. Further analysis, under different environmental conditions and validation is required before the approach can be used to help adjust fertiliser management practices to temporal and spatial N demand based on the nitrogen status of the pasture.

Keywords: APSIM modelling, optimum N fertilization rate, pasture N content, ryegrass pasture, three dimensional surface response function.

Procedia PDF Downloads 121
6053 Prevalence and Pattern of Modern Contraceptive Use among Chittagong City Slum Dwellers in Bangladesh

Authors: Tahera Begum, Sabina Yeasmin, Jalal Uddin

Abstract:

Ten slums of ten wards of Chittagong city corporation of Bangladesh were conveniently selected to know about modern contraceptive use by the slum dwellers. Total 300 family heads or their wives were interviewed with a questionnaire in February 2014. Family size was 4.62. Among 300 families 248 eligible couples were found. 57% eligible couples use different modern contraceptive measures. Remaining 43% eligible couples do not use modern contraceptive measures. Among the users 58% use oral pill, 30% injectables, 8% use condom, 3% were found with ligation and only 1% with vasectomy. Contraceptive prevalence rate has been increased and pattern as changed. A discussion is made with literature review.

Keywords: conraceptive, Bangladesh, family, pill

Procedia PDF Downloads 463
6052 The Residual Efficacy of Etofenprox WP on Different Surfaces for Malaria Control in the Brazilian Legal Amazon

Authors: Ana Paula S. A. Correa, Allan K. R. Galardo, Luana A. Lima, Talita F. Sobral, Josiane N. Muller, Jessica F. S. Barroso, Nercy V. R. Furtado, Ednaldo C. Rêgo., Jose B. P. Lima

Abstract:

Malaria is a public health problem in the Brazilian Legal Amazon. Among the integrated approaches for anopheline control, the Indoor Residual Spraying (IRS) remains one of the main tools in the basic strategy applied in the Amazonian States, where the National Malaria Control Program currently uses one of the insecticides from the pyrethroid class, the Etofenprox WP. Understanding the residual efficacy of insecticides on different surfaces is essential to determine the spray cycles, in order to maintain a rational use and to avoid product waste. The aim of this study was to evaluate the residual efficacy of Etofenprox - VECTRON ® 20 WP on surfaces of Unplastered Cement (UC) and Unpainted Wood (UW) on panels, in field, and in semi-field evaluation of Brazil’s Amapa State. The evaluation criteria used was the cone bioassay test, following the World Health Organization (WHO) recommended method, using plastic cones and female mosquitos of Anopheles sp. The tests were carried out in laboratory panels, semi-field evaluation in a “test house” built in the Macapa municipality, and in the field in 20 houses, being ten houses per surface type (UC and UW), in an endemic malaria area in Mazagão’s municipality. The residual efficacy was measured from March to September 2017, starting one day after the spraying, repeated monthly for a period of six months. The UW surface presented higher residual efficacy than the UC. In fact, the UW presented a residual efficacy of the insecticide throughout the period of this study with a mortality rate above 80% in the panels (= 95%), in the "test house" (= 86%) and in field houses ( = 87%). On the UC surface it was observed a mortality decreased in all the tests performed, with a mortality rate of 45, 47 and 29% on panels, semi-field and in field, respectively; however, the residual efficacy ≥ 80% only occurred in the first evaluation after the 24-hour spraying bioassay in the "test house". Thus, only the UW surface meets the specifications of the World Health Organization Pesticide Evaluation Scheme (WHOPES) regarding the duration of effective action (three to six months). To sum up, the insecticide residual efficacy presented variability on the different surfaces where it was sprayed. Although the IRS with Etofenprox WP was efficient on UW surfaces, and it can be used in spraying cycles at 4-month intervals, it is important to consider the diversity of houses in the Brazilian Legal Amazon, in order to implement alternatives for vector control, including the evaluation of new products or different formulations types for insecticides.

Keywords: Anopheles, vector control, insecticide, bioassay

Procedia PDF Downloads 151
6051 A Study of a Plaque Inhibition Through Stenosed Bifurcation Artery considering a Biomagnetic Blood Flow and Elastic Walls

Authors: M. A. Anwar, K. Iqbal, M. Razzaq

Abstract:

Background and Objectives: This numerical study reflects the magnetic field's effect on the reduction of plaque formation due to stenosis in a stenosed bifurcated artery. The entire arterythe wall is assumed as linearly elastic, and blood flow is modeled as a Newtonian, viscous, steady, incompressible, laminar, biomagnetic fluid. Methods: An Arbitrary Lagrangian-Eulerian (ALE) technique is employed to formulate the hemodynamic flow in a bifurcated artery under the effect of the asymmetric magnetic field by two-way Fluid-structure interaction coupling. A stable P2P1 finite element pair is used to discretize thenonlinear system of partial differential equations. The resulting nonlinear system of algebraic equations is solved by the Newton Raphson method. Results: The numerical results for displacement, velocity magnitude, pressure, and wall shear stresses for Reynolds numbers, Re = 500, 1000, 1500, 2000, in the presence of magnetic fields are presented graphically. Conclusions: The numerical results show that the presence of the magnetic field influences the displacement and flows velocity magnitude considerably. The magnetic field reduces the flow separation, recirculation area adjacent to stenosis and gives rise to wall shear stress.

Keywords: bifurcation, elastic walls, finite element, wall shear stress,

Procedia PDF Downloads 158
6050 Improved Performance Scheme for Joint Transmission in Downlink Coordinated Multi-Point Transmission

Authors: Young-Su Ryu, Su-Hyun Jung, Myoung-Jin Kim, Hyoung-Kyu Song

Abstract:

In this paper, improved performance scheme for joint transmission is proposed in downlink (DL) coordinated multi-point(CoMP) in case of constraint transmission power. This scheme is that serving transmission point (TP) request a joint transmission to inter-TP and selects one pre-coding technique according to channel state information(CSI) from user equipment(UE). The simulation results show that the bit error rate(BER) and throughput performances of the proposed scheme provide high spectral efficiency and reliable data at the cell edge.

Keywords: CoMP, joint transmission, minimum mean square error, zero-forcing, zero-forcing dirty paper coding

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6049 All-Optical Function Based on Self-Similar Spectral Broadening for 2R Regeneration in High-Bit-Rate Optical Transmission Systems

Authors: Leila Graini

Abstract:

In this paper, we demonstrate basic all-optical functions for 2R regeneration (Re-amplification and Re-shaping) based on self-similar spectral broadening in low normal dispersion and highly nonlinear fiber (ND-HNLF) to regenerate the signal through optical filtering including the transfer function characteristics, and output extinction ratio. Our approach of all-optical 2R regeneration is based on those of Mamyshev. The numerical study reveals the self-similar spectral broadening very effective for 2R all-optical regeneration; the proposed design presents high stability compared to a conventional regenerator using SPM broadening with reduction of the intensity fluctuations and improvement of the extinction ratio.

Keywords: all-optical function, 2R optical regeneration, self-similar broadening, Mamyshev regenerator

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6048 Consumption and Diffusion Based Model of Tissue Organoid Development

Authors: Elena Petersen, Inna Kornienko, Svetlana Guryeva, Sergey Simakov

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In vitro organoid cultivation requires the simultaneous provision of necessary vascularization and nutrients perfusion of cells during organoid development. However, many aspects of this problem are still unsolved. The functionality of vascular network intergrowth is limited during early stages of organoid development since a function of the vascular network initiated on final stages of in vitro organoid cultivation. Therefore, a microchannel network should be created in early stages of organoid cultivation in hydrogel matrix aimed to conduct and maintain minimally required the level of nutrients perfusion for all cells in the expanding organoid. The network configuration should be designed properly in order to exclude hypoxic and necrotic zones in expanding organoid at all stages of its cultivation. In vitro vascularization is currently the main issue within the field of tissue engineering. As perfusion and oxygen transport have direct effects on cell viability and differentiation, researchers are currently limited only to tissues of few millimeters in thickness. These limitations are imposed by mass transfer and are defined by the balance between the metabolic demand of the cellular components in the system and the size of the scaffold. Current approaches include growth factor delivery, channeled scaffolds, perfusion bioreactors, microfluidics, cell co-cultures, cell functionalization, modular assembly, and in vivo systems. These approaches may improve cell viability or generate capillary-like structures within a tissue construct. Thus, there is a fundamental disconnect between defining the metabolic needs of tissue through quantitative measurements of oxygen and nutrient diffusion and the potential ease of integration into host vasculature for future in vivo implantation. A model is proposed for growth prognosis of the organoid perfusion based on joint simulations of general nutrient diffusion, nutrient diffusion to the hydrogel matrix through the contact surfaces and microchannels walls, nutrient consumption by the cells of expanding organoid, including biomatrix contraction during tissue development, which is associated with changed consumption rate of growing organoid cells. The model allows computing effective microchannel network design giving minimally required the level of nutrients concentration in all parts of growing organoid. It can be used for preliminary planning of microchannel network design and simulations of nutrients supply rate depending on the stage of organoid development.

Keywords: 3D model, consumption model, diffusion, spheroid, tissue organoid

Procedia PDF Downloads 301
6047 Evaluation of DNA Oxidation and Chemical DNA Damage Using Electrochemiluminescent Enzyme/DNA Microfluidic Array

Authors: Itti Bist, Snehasis Bhakta, Di Jiang, Tia E. Keyes, Aaron Martin, Robert J. Forster, James F. Rusling

Abstract:

DNA damage from metabolites of lipophilic drugs and pollutants, generated by enzymes, represents a major toxicity pathway in humans. These metabolites can react with DNA to form either 8-oxo-7,8-dihydro-2-deoxyguanosine (8-oxodG), which is the oxidative product of DNA or covalent DNA adducts, both of which are genotoxic and hence considered important biomarkers to detect cancer in humans. Therefore, detecting reactions of metabolites with DNA is an effective approach for the safety assessment of new chemicals and drugs. Here we describe a novel electrochemiluminescent (ECL) sensor array which can detect DNA oxidation and chemical DNA damage in a single array, facilitating a more accurate diagnostic tool for genotoxicity screening. Layer-by-layer assembly of DNA and enzyme are assembled on the pyrolytic graphite array which is housed in a microfluidic device for sequential detection of two type of the DNA damages. Multiple enzyme reactions are run on test compounds using the array, generating toxic metabolites in situ. These metabolites react with DNA in the films to cause DNA oxidation and chemical DNA damage which are detected by ECL generating osmium compound and ruthenium polymer, respectively. The method is further validated by the formation of 8-oxodG and DNA adduct using similar films of DNA/enzyme on magnetic bead biocolloid reactors, hydrolyzing the DNA, and analyzing by liquid chromatography-mass spectrometry (LC-MS). Hence, this combined DNA/enzyme array/LC-MS approach can efficiently explore metabolic genotoxic pathways for drugs and environmental chemicals.

Keywords: biosensor, electrochemiluminescence, DNA damage, microfluidic array

Procedia PDF Downloads 352
6046 The Effect of Crack Size, Orientation and Number on the Elastic Modulus of a Cracked Body

Authors: Mark T. Hanson, Alan T. Varughese

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Osteoporosis is a disease affecting bone quality which in turn can increase the risk of low energy fractures. Treatment of osteoporosis using Bisphosphonates has the beneficial effect of increasing bone mass while at the same time has been linked to the formation of atypical femoral fractures. This has led to the increased study of micro-fractures in bones of patients using Bisphosphonate treatment. One of the mechanics related issues which have been identified in this regard is the loss in stiffness of bones containing one or many micro-fractures. Different theories have been put forth using fracture mechanics to determine the effect of crack presence on elastic properties such as modulus. However, validation of these results in a deterministic way has not been forthcoming. The present analysis seeks to provide this deterministic evaluation of fracture’s effect on the elastic modulus. In particular, the effect of crack size, crack orientation and crack number on elastic modulus is investigated. In particular, the Finite Element method is used to explicitly determine the elastic modulus reduction caused by the presence of cracks in a representative volume element. Single cracks of various lengths and orientations are examined as well as cases of multiple cracks. Cracks in tension as well as under shear stress are considered. Although the focus is predominantly two-dimensional, some three-dimensional results are also presented. The results obtained show the explicit reduction in modulus caused by the parameters of crack size, orientation and number noted above. The present results allow the interpretation of the various theories which currently exist in the literature.

Keywords: cracks, elastic, fracture, modulus

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6045 Soil-Vegetation Relationship in the Watersheds of the Tonga and OubeïRa Lakes, Algeria

Authors: Nafaa Zaafour

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Located at the north eastern of Algeria, the National Park of El-Kala (PNEK) is a set of landscapes whose bioclimatic stages of vegetation extend from sub-humid to humid. In order to know the soil occupation in this complex, an initiated ecological soil cartography using a stratified sampling plan of vegetation had made, the study area occupies two-thirds of the northern National Park of El Kala, it has been divided into 380 plots of 1km2 of which, 76 were the subject of a detailed floristic inventory and sampling of soils. The inventory of vegetation carried out on different sites has allowed identifying several plant groups that share the soil cover with the following distribution: The group of cork oak, this formation occupies the biggest part of the area, it develops mainly on Incepttisols, Alfisols and Mollisols; The group of kermes oak, occupies a large area, it grows on Mollisols and Alfisols; The group of maritime pine, it occupies the same soils as the Kermes Oak; The group of Mirbeck oak, installed on Regosols, it is located in the Eastern part, on the Algerian-Tunisian border; The group of eucalyptus, it grows mainly on Inceptisols, Mollisols of, and Vertisols; The group of wetland, it grows along the banks of lakes and rivers, which primarily develops on Histosols soil Mollisols and Vertisols; The cultures, distributed mainly around the lakes occupy several soil types on Histosols, the Inceptisols, Mollisols of, and Vertisols. This great diversity of vegetation is linked not only to the soil variability but also to climate, hydrological and geological variability.

Keywords: Algeria, cartography, soil, vegetation

Procedia PDF Downloads 363
6044 Developmental Differences of Elementary School Children in Knowledge Acquisition Following a Sexual Abuse Prevention Program

Authors: Chrysanthi Nega, Fotini-Sonia Apergi

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Child sexual abuse (CSA) in Greece is a highly prevalent phenomenon and yet remains largely underreported. CSA can negatively impact cognitive, emotional and psychosocial development, as well as personality formation and capacity for initiation and maintenance of healthy interpersonal relationships. It is particularly important for school-based prevention programs to be implemented early in elementary school, as they are reportedly effective in lowering abuse incidences and providing knowledge for coping in threatening environments. The purpose of the current study was to test the effectiveness of a school-based CSA prevention program (Safe-Touches) on Greek elementary school students (grades 1-3, N=272) and explore the effect of age and time of testing (academic term). There was a significant effect of age in the knowledge of Inappropriate Touch, when comparing pre and post-intervention assessments, with third graders showing greatest gains in knowledge, followed by second and first graders. Time of testing during the academic year also had a significant effect, as first graders tested later in the school year, scored higher on knowledge of Inappropriate Touch. The findings of the current study provide insight into the optimal timing to implement CSA prevention programs. Exposure to such programs and incorporation in the school curricula could largely benefit children of the Greek community in terms of safety and awareness.

Keywords: child sexual abuse, Safe-Touches, school-based prevention, schooling

Procedia PDF Downloads 305
6043 Factors Affecting Aluminum Dissolve from Acidified Water Purification Sludge

Authors: Wen Po Cheng, Chi Hua Fu, Ping Hung Chen, Ruey Fang Yu

Abstract:

Recovering resources from water purification sludge (WPS) have been gradually stipulated in environmental protection laws and regulations in many nations. Hence, reusing the WPS is becoming an important topic, and recovering alum from WPS is one of the many practical alternatives. Most previous research efforts have been conducted on studying the amphoteric characteristic of aluminum hydroxide for investigating the optimum pH range to dissolve the Al(III) species from WPS, but it has been lack of reaction kinetics or mechanisms related discussion. Therefore, in this investigation, water purification sludge (WPS) solution was broken by ultrasound to make particle size of reactants smaller, specific surface area larger. According to the reaction kinetics, these phenomena let the dissolved aluminum salt quantity increased and the reaction rate go faster.

Keywords: aluminum, acidification, sludge, recovery

Procedia PDF Downloads 606
6042 Self-Action of Pyroelectric Spatial Soliton in Undoped Lithium Niobate Samples with Pyroelectric Mechanism of Nonlinear Response

Authors: Anton S. Perin, Vladimir M. Shandarov

Abstract:

Compensation for the nonlinear diffraction of narrow laser beams with wavelength of 532 and the formation of photonic waveguides and waveguide circuits due to the contribution of pyroelectric effect to the nonlinear response of lithium niobate crystal have been experimentally demonstrated. Complete compensation for the linear and nonlinear diffraction broadening of light beams is obtained upon uniform heating of an undoped sample from room temperature to 55 degrees Celsius. An analysis of the light-field distribution patterns and the corresponding intensity distribution profiles allowed us to estimate the spacing for the channel waveguides. The observed behavior of bright soliton beams may be caused by their coherent interaction, which manifests itself in repulsion for anti-phase light fields and in attraction for in-phase light fields. The experimental results of this study showed a fundamental possibility of forming optically complex waveguide structures in lithium niobate crystals with pyroelectric mechanism of nonlinear response. The topology of these structures is determined by the light field distribution on the input face of crystalline sample. The optical induction of channel waveguide elements by interacting spatial solitons makes it possible to design optical systems with a more complex topology and a possibility of their dynamic reconfiguration.

Keywords: self-action, soliton, lithium niobate, piroliton, photorefractive effect, pyroelectric effect

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6041 OFDM Radar for Detecting a Rayleigh Fluctuating Target in Gaussian Noise

Authors: Mahboobeh Eghtesad, Reza Mohseni

Abstract:

We develop methods for detecting a target for orthogonal frequency division multiplexing (OFDM) based radars. As a preliminary step we introduce the target and Gaussian noise models in discrete–time form. Then, resorting to match filter (MF) we derive a detector for two different scenarios: a non-fluctuating target and a Rayleigh fluctuating target. It will be shown that a MF is not suitable for Rayleigh fluctuating targets. In this paper we propose a reduced-complexity method based on fast Fourier transfrom (FFT) for such a situation. The proposed method has better detection performance.

Keywords: constant false alarm rate (CFAR), match filter (MF), fast Fourier transform (FFT), OFDM radars, Rayleigh fluctuating target

Procedia PDF Downloads 341
6040 A Study on Waste Management Policy in Minamata City Kumamoto Prefecture Japan

Authors: Qiannan Zhuo, Wanglin Yan

Abstract:

Minamata City and its citizens have been suffered from Minamata Disease, one of the worst environmental problems in Japan, since 1956. To mitigate the bad images brought by Minamata Disease, Minamata City has started a series of environmental friendly activities from 60 years ago. Garbage separation is the very beginning one. It has been already done for more than 20 years since Minamata citizens started to separate their garbage into more than 20 categories. In this research, the author evaluated the effectiveness of the waste management policy in Minamata city by analyzing the recycle rate and the landfill amount., and also pointed out the problems brought by it through the qualitative survey.

Keywords: Minamata City, households waste, garbage separation, recycle reduce reuse

Procedia PDF Downloads 225
6039 The Tribological Behaviors of Vacuum Gas Nitriding Titanium and Steel Substrates at Different Process Temperatures

Authors: Hikmet Cicek

Abstract:

Metal nitrides show excellence tribological properties and they used for especially on machine parts. In this work, the vacuum gas nitriding proses were applied to the titanium, D2 and 52100 steel substrates at three different proses temperatures (500 °C, 600°C and 700 °C). Structural, mechanical and tribological properties of the samples were characterized. X-Ray diffractometer, scanning electron microscope and energy dispersive spectroscopy analyses were conducted to determine structural properties. Microhardness test and pin-on-disc wear test were made to observe tribological properties. Coefficient of friction, wear rate and wear traces were examined comparatively. According to the test results, the process temperature very effective parameter for the vacuum gas nitriding method.

Keywords: gas nitriding, tribology, wear, coating

Procedia PDF Downloads 193
6038 Retrospective Study on the Impacts of Age, Gender, Economic Status, Education Level and Drug Availability in Public Hospital on Seeking Care of Dermatological Condition in Rwanda

Authors: Uwizera Egide

Abstract:

Introduction: Dermatological conditions are one of the most burdensome diseases in our health system. Global studies suggest that around 1 in 3 people gets a skin disease at a certain point in their life, though this does not necessarily guarantee the urge to consult. For a high-ranking disease, it is surprising how there is not enough data to support its effect on the economy and the general health system impact. It is for that reason that this study’s aim is to identify the burden of dermatological conditions in Rwanda so as to have a general picture of what our population is going through in regards to dermatological conditions. Methods: We used a cross sectional retrospective study. Data were obtained from patient’s information recorded in an open clinic at CHUB in a period of six months from July to December of the year 2021. Results: The study had a total of 4600 patients who attended dermatology service in a period of six months from July to December of the year 2021. We found a list of 102 dermatological diseases that presented at variable rates. The most prevalent disease was atopic dermatitis, at a rate of 23%. About 90% of presented conditions had only one choice of treatment from the hospital pharmacy. Most patients who presented were between 18-35 years old and with a predominance of the female gender; the level of education was either secondary or University Degree in our study, 65.4% of patients who presented were female; the majority, around 45% were between 18-35 years old, mostly being single 56%. The majority came from Southern province as it is the location of the hospital. The insurance mostly used was community-based health insurance with 63.8%, followed by RSSB with 18.5%, MS/UR, and other private insurances. The frequency of group drugs prescribed among all dermatological medications, steroids were the most commonly given medications at a rate of 39%, followed by emollients, antibiotics, and antifungal. The drugs prescribed were mostly available in the pharmacy of CHUB, with 60% and 40% being found in pharmacies outside the hospital. Conclusion: Dermatological conditions are prevalent in all age groups and distributed through all socioeconomic classes. About 9.2% of patient who consulted CHUB in 2021 presented one Dermatological condition of which 40 % of prescribed medications is never found in Hospital urging a need to buy medication in private pharmacies with more expenses and a risk of not complying on prescribed medication if in case they can’t afford paying them outside the CHUB. This finding urges a need to avail all essential dermatological drugs in hospital pharmacies to allow our patients to get them for the proper compliance of prescribed drugs in the management of skin diseases.

Keywords: atopic dermatitis, CHUB (centre hopitalier univerisitaire de butare), dermatological condition, fungal infections

Procedia PDF Downloads 95
6037 Characterization of Heterotrimeric G Protein α Subunit in Tomato

Authors: Thi Thao Ninh, Yuri Trusov, José Ramón Botella

Abstract:

Heterotrimeric G proteins, comprised of three subunits, α, β and γ, are involved in signal transduction pathways that mediate a vast number of processes across the eukaryotic kingdom. 23 Gα subunits are present in humans whereas most plant genomes encode for only one canonical Gα. The disparity observed between Arabidopsis, rice, and maize Gα-deficient mutant phenotypes suggest that Gα functions have diversified between eudicots and monocots during evolution. Alternatively, since the only Gα mutations available in dicots have been produced in Arabidopsis, the possibility exists that this species might be an exception to the rule. In order to test this hypothesis, we studied the G protein α subunit (TGA1) in tomato. Four tga1 knockout lines were generated in tomato cultivar Moneymaker using CRISPR/Cas9. The tga1 mutants exhibit a number of auxin-related phenotypes including changes in leaf shape, reduced plant height, fruit size and number of seeds per fruit. In addition, tga1 mutants have increased sensitivity to abscisic acid during seed germination, reduced sensitivity to exogenous auxin during adventitious root formation from cotyledons and excised hypocotyl explants. Our results suggest that Gα mutant phenotypes in tomato are very similar to those observed in monocots, i.e. rice and maize, and cast doubts about the validity of using Arabidopsis as a model system for plant G protein studies.

Keywords: auxin-related phenotypes, CRISPR/Cas9, G protein α subunit, heterotrimeric G proteins, tomato

Procedia PDF Downloads 118
6036 Population Structure Analysis of Pakistani Indigenous Cattle Population by Using High Density SNP Array

Authors: Hamid Mustafa, Huson J. Heather, Kim Eiusoo, McClure Matt, Khalid Javed, Talat Nasser Pasha, Afzal Ali1, Adeela Ajmal, Tad Sonstegard

Abstract:

Genetic differences associated with speciation, breed formation or local adaptation can help to preserve and effective utilization of animals in selection programs. Analyses of population structure and breed diversity have provided insight into the origin and evolution of cattle. In this study, we used a high-density panel of SNP markers to examine population structure and diversity among ten Pakistani indigenous cattle breeds. In total, 25 individuals from three cattle populations, including Achi (n=08), Bhagnari (n=04) and Cholistani (n=13) were genotyped for 777, 962 single nucleotide polymorphism (SNP) markers. Population structure was examined using the linkage model in the program STRUCTURE. After characterizing SNP polymorphism in the different populations, we performed a detailed analysis of genetic structure at both the individual and population levels. The whole-genome SNP panel identified several levels of population substructure in the set of examined cattle breeds. We further searched for spatial patterns of genetic diversity among these breeds under the recently developed spatial principal component analysis framework. Overall, such high throughput genotyping data confirmed a clear partitioning of the cattle genetic diversity into distinct breeds. The resulting complex historical origins associated with both natural and artificial selection have led to the differentiation of numerous different cattle breeds displaying a broad phenotypic variety over a short period of time.

Keywords: Pakistan, cattle, genetic diversity, population structure

Procedia PDF Downloads 599
6035 Study of COVID-19 Intensity Correlated with Specific Biomarkers and Environmental Factors

Authors: Satendra Pal Singh, Dalip Kr. Kakru, Jyoti Mishra, Rajesh Thakur, Tarana Sarwat

Abstract:

COVID-19 is still an intrigue as far as morbidity or mortality is concerned. The rate of recovery varies from person to person, & it depends upon the accessibility of the healthcare system and the roles played by the physicians and caregivers. It is envisaged that with the passage of time, people would become immune to this virus, and those who are vulnerable would sustain themselves with the help of vaccines. The proposed study deals with the severeness of COVID-19 is associated with some specific biomarkers linked to correlate age and gender. We will be assessing the overall homeostasis of the persons who were affected by the coronavirus infection and also of those who recovered from it. Some people show more severe effects, while others show very mild symptoms, however, they show low CT values. Thus far, it is unclear why the new strain of Covid has different effects on different people in terms of age, gender, and ABO blood typing. According to data, the fatality rate with heart disease was 10.5 percent, 7.3 percent were diabetic, and 6 percent who are already infected from other comorbidities. However, some COVID-19 cases are worse than others & it is not fully explainable as of date. Overall data show that the ABO blood group is effective or prone to the risk of SARS-COV2 infection, while another study also shows the phenotypic effects of the blood group related to covid. It is an accepted fact that females have more strong immune systems than males, which may be related to the fact that females have two ‘X’ chromosomes, which might contain a more effective immunity booster gene on the X chromosome, and are capable to protect the female. Also specific sex hormones also induce a better immune response in a specific gender. This calls for in-depth analysis to be able to gain insight into this dilemma. COVID-19 is still not fully characterized, and thus we are not very familiar with its biology, mode of infection, susceptibility, and overall viral load in the human body. How many virus particles are needed to infect a person? How, then, comorbidity contribute to coronavirus infection? Since the emergence of this virus in 2020, a large number of papers have been published, and seemingly, vaccines have been prepared. But still, a large number of questions remain unanswered. The proneness of humans for infection by covid-19 needs to be established to be able to develop a better strategy to fight this virus. Our study will be on the Impact of demography on the Severity of covid-19 infection & at the same time, will look into gender-specific sensitivity of Covid-19 and the Operational variation of different biochemical markers in Covid-19 positive patients. Besides, we will be studying the co-relation, if any, of COVID severity & ABO Blood group type and the occurrence of the most common blood group type amongst positive patience.

Keywords: coronavirus, ABO blood group, age, gender

Procedia PDF Downloads 81
6034 Using a Hybrid Method to Eradicate Bamboo Growth along the Route of Overhead Power Lines

Authors: Miriam Eduful

Abstract:

The Electricity Company of Ghana (ECG) is under obligation, demanded by the Public Utility and Regulation Commission to meet set performance indices. However, in certain parts of the country, bamboo related power interruptions have become a challenge. Growth rate of the bamboo is such that the cost of regular vegetation maintenance along route of the overhead power lines has become prohibitive. To address the problem, several methods and techniques of bamboo eradication have being used. Some of these methods involved application of chemical compounds that are considered inimical and dangerous to the environment. In this paper, three methods of bamboo eradication along the route of the ECG overhead power lines have been investigated. A hybrid method has been found to be very effective and ecologically friendly. The method is locally available and comparatively inexpensive to apply.

Keywords: bamboo, eradication, hybrid method, gly gold

Procedia PDF Downloads 350