Search results for: conditional proportional reversed hazard rate model

Authors: Vijay nandmer, Ajay Nandmer

Abstract:

Stigmatized psycho-social perception poses a serious challenge and source of discrimination which impedes stroke patients from attaining a satisfactory quality of life. The present study was aimed to obtain information on knowledge, attitudes and practices (KAP) of stroke patients in the institute. We included 1000 people in our random sampling survey. Demographic details and responses to a questionnaire assessing the knowledge, attitude and practices were recorded. Although the majority of the patients belonged to low socioeconomic strata, the literacy rate was reasonably high (96.3%). A large majority (91.3%) of people had heard about stroke and (85.2%) knew that stroke can be treated with modern drugs. However, a negative attitude was reflected in the belief that stroke happens due to supernatural powers (hawa lagne se) (50.6%). Analysis of the data revealed regional differences in KAP which could be attributed to local Factors, such as literacy, awareness about stroke, and practice of different systems of medicine. Some of the differences can also be attributed to a category of study population whether it included patients or non-stroke individuals since the former are likely to have less negative attitudes than the public. There is a need to create awareness about stroke on a nation-wide basis to dispel the misconceptions and stigma through effective and robust programs with the aim to lessen the disease burden.

Keywords: epidemiology, sroke, literacy, stroke

Procedia PDF Downloads 394

Authors: Alpha Matthew

Abstract:

The Composites of Al-Doped K₂CO₃ activated coconut husk carbon, Al₀.₁:(K₂CO₃C)₀.₉ and AI₀.₃:(K₂CO₃C)₀.₇, were prepared using the hydrothermal method and drop casting deposition technique. The electrochemical performance of the Al-doped K₂CO₃ activated coconut husk carbon composite as a promising anode material for lithium-ion batteries was characterised by cyclic voltammetry analysis, electrochemical impedance spectroscopy, and galvanostatic charge discharge analysis. The charges that are retained in the anode material during charging showed a linear decline in charge capacity as the charging current intensity increased. Ionic polarisation was the reason for the observed drop in the charge and discharge capabilities at the current density of 5 A/g. Having greater specific capacitance and energy density, the composite Al₀.₁:(K₂CO₃C)₀.₉ is a better anode material for electrochemical applications compared to AI₀.₃:(K₂CO₃C)₀.₇, also its comparatively higher power density at a scan rate of 5 mV/s is mostly explained by its lower equivalent series resistance.

Keywords: coconut carbon husk, power density, energy density, battery, anode electrode

Procedia PDF Downloads 34

Authors: Keltoum Bouherine, Olivier Leroy

Abstract:

The present work is dedicated to study a three–dimensional (3D) self-consistent fluid simulation of microwave discharges of argon plasma in PECVD reactor. The model solves the Maxwell’s equations, continuity equations for charged species and the electron energy balance equation, coupled with Poisson’s equation, and Navier-Stokes equations by finite element method, using COMSOL Multiphysics software. In this study, the simulations yield the profiles of plasma components as well as the charge densities and electron temperature, the electric field, the gas velocity, and gas temperature. The results show that the microwave plasma reactor is outside of local thermodynamic equilibrium.The present work is dedicated to study a three–dimensional (3D) self-consistent fluid simulation of microwave discharges of argon plasma in PECVD reactor. The model solves the Maxwell’s equations, continuity equations for charged species and the electron energy balance equation, coupled with Poisson’s equation, and Navier-Stokes equations by finite element method, using COMSOL Multiphysics software. In this study, the simulations yield the profiles of plasma components as well as the charge densities and electron temperature, the electric field, the gas velocity, and gas temperature. The results show that the microwave plasma reactor is outside of local thermodynamic equilibrium.

Keywords: electron density, electric field, microwave plasma reactor, gas velocity, non-equilibrium plasma

Procedia PDF Downloads 337

Authors: Yuet Wah Echo Yeung

Abstract:

Working with people from minority ethnic groups, refugees and asylum seeking communities who have limited proficiency in the language of the host country often presents a major challenge for social workers. Because of language differences, social workers need to work with interpreters to ensure accurate information is collected for their assessment and intervention. Drawing from social learning theory, this paper discusses how role play was used as an experiential learning exercise in a training session to help social work students develop skills when working with interpreters. Social learning theory posits that learning is a cognitive process that takes place in a social context when people observe, imitate and model others’ behaviours. The roleplay also helped students understand the role of the interpreter and the challenges they may face when they rely on interpreters to communicate with service users and their family. The first part of the session involved role play. A tutor played the role of social worker and deliberately behaved in an unprofessional manner and used inappropriate body language when working alongside the interpreter during a home visit. The purpose of the roleplay is not to provide a positive role model for students to ‘imitate’ social worker’s behaviours. Rather it aims to active and provoke internal thinking process and encourages students to critically consider the impacts of poor practice on relationship building and the intervention process. Having critically reflected on the implications for poor practice, students were then asked to play the role of social worker and demonstrate what good practice should look like. At the end of the session, students remarked that they learnt a lot by observing the good and bad example; it showed them what not to do. The exercise served to remind students how practitioners can easily slip into bad habits and of the importance of respect for the cultural difference when working with people from different cultural backgrounds.

Keywords: role play, social learning theory, social work practice, working with interpreters

Procedia PDF Downloads 183

Authors: Ivan Poza Martínez

Abstract:

The international energy landscape has been significantly affected by the Covid-19 pandemic and te conflict in Ukraine. The Vaca Muerta sedimentary formation in Argentina´s Neuquén province has become a crucial area for energy production, specifically in the shale gas ad shale oil sectors. The massive investment required for theexploitation of this reserve make it essential to understand te determinants of the investment in the upstream sector at both local ad international levels. The aim of this study is to identify the qualitative and quantitative determinants of investment in Vaca Muerta. The research methodolody employs both quantiative ( econometrics ) and qualitative approaches. A linear regression model is used to analyze the impact in non-conventional hydrocarbons. The study highlights that, in addition to quantitative factors, qualitative variables, particularly the design of a regulatory framework, significantly influence the level of the investment in Vaca Muerta. The analysis reveals the importance of attracting both domestic and foreign capital investment. This research contributes to understanding the factors influencing investment inthe Vaca Muerta regioncomapred to other published studies. It emphasizes to role of qualitative varibles, such as regulatory frameworks, in the development of the shale gas and oil sectors. The study uses a combination ofquantitative data , such a investment figures, and qualitative data, such a regulatory frameworks. The data is collected from various rpeorts and industry publications. The linear regression model is used to analyze the relationship between the variables and the investment in Vaca Muerta. The research addresses the question of what factors drive investment in the Vaca Muerta region, both from a quantitative and qualitative perspective. The study concludes that a combination of quantitative and qualitative factors, including the design of a regulatory framework, plays a significant role in attracting investment in Vaca Muerta. It highlights the importance of these determinants in the developmentof the local energy sector and the potential economic benefits for Argentina and the Southern Cone region.

Keywords: vaca muerta, FDI, shale gas, shale oil, YPF

Procedia PDF Downloads 61

Authors: Redhouane Ghernaout, Amira Fredj, Boualem Remini

Abstract:

Suspended sediment transport is a serious problem worldwide, but it is much more worrying in certain regions of the world, as is the case in the Maghreb and more particularly in Algeria. It continues to take disturbing proportions in Northern Algeria due to the variability of rains in time and in space and constant deterioration of vegetation. Its prediction is essential in order to identify its intensity and define the necessary actions for its reduction. The purpose of this study is to analyze the concentration data of suspended sediment measured at Wadi El-Abtal Hydrometric Station. It also aims to find and highlight regressive power relationships, which can explain the suspended solid flow by the measured liquid flow. The study strives to find models of artificial neural networks linking the flow, month and precipitation parameters with solid flow. The obtained results show that the power function of the solid transport rating curve and the models of artificial neural networks are appropriate methods for analysing and estimating suspended sediment transport in Wadi Mina at Wadi El-Abtal Hydrometric Station. They made it possible to identify in a fairly conclusive manner the model of neural networks with four input parameters: the liquid flow Q, the month and the daily precipitation measured at the representative stations (Frenda 013002 and Ain El-Hadid 013004 ) of the watershed. The model thus obtained makes it possible to estimate the daily solid flows (interpolate and extrapolate) even beyond the period of observation of solid flows (1985/86 to 1999/00), given the availability of the average daily liquid flows and daily precipitation since 1953/1954.

Keywords: suspended sediment, concentration, regression, liquid flow, solid flow, artificial neural network, modeling, mina, algeria

Procedia PDF Downloads 108

Authors: Surendra Kumar Chourasiya, Sandeep Kumar, Devendra Singh

Abstract:

In the present investigation tribological behavior of Al-6Si-1Mg-1Graphite composite has been explained. The composite was developed through the unique spray forming route in the spray forming chamber by using N₂ gas at 7kg/cm² and the flight distance was 400 mm. Spray formed composite having a certain amount of porosity which was reduced by the deformations. The composite was subjected to the warm rolling (WR) at 250ºC up to 40% reduction. Spray forming composite shows the considerable microstructure refinement, equiaxed grains, distribution of silicon and graphite particles in the primary matrix of the composite. Graphite (Gr) was incorporated externally during the process that works as a solid lubricant. Porosity decreased after reduction and hardness increases. Pin on disc test has been performed to analyze the wear behavior which is the function of sliding distance for all percent reduction of the composite. 30% WR composite shows the better result of wear rate and coefficient of friction. The improved wear properties of the composite containing Gr are discussed in light of the microstructural features of spray formed the composite and the nature of the debris particles. Scanning electron microscope and optical microscope analysis of the present material supported the prediction of aforementioned changes.

Keywords: Al-6Si-1Mg-1Graphite, spray forming, warm rolling, wear

Procedia PDF Downloads 569

Authors: K. Jahani, J. Razavi

Abstract:

Nowadays, to decrease the number of downtimes in the industries such as metal mining, petroleum and chemical industries, predictive maintenance is crucial. In order to have efficient predictive maintenance, knowing the performance of critical equipment of production line such as pumps and hydro-cyclones under variable operating parameters, selecting best indicators of this equipment health situations, best locations for instrumentation, and also measuring of these indicators are very important. In this paper, computer aided engineering (CAE) tools are implemented to study some important elements of copper process line, namely slurry pumps and cyclone to predict the performance of these components under different working conditions. These modeling and simulations can be used in predicting, for example, the damage tolerance of the main shaft of the slurry pump or wear rate and location of cyclone wall or pump case and impeller. Also, the simulations can suggest best-measuring parameters, measuring intervals, and their locations.

Keywords: computer aided engineering, predictive maintenance, fault detection, mining process line, slurry pump, hydrocyclone

Procedia PDF Downloads 407

Authors: Etienne Gaborit, Dorothy Durnford, Daniel Deacu, Marco Carrera, Nathalie Gauthier, Camille Garnaud, Vincent Fortin

Abstract:

A new experimental streamflow forecasting system was recently implemented at the Environment and Climate Change Canada’s (ECCC) Canadian Centre for Meteorological and Environmental Prediction (CCMEP). It relies on CaLDAS (Canadian Land Data Assimilation System) for the assimilation of surface variables, and on a surface prediction system that feeds a routing component. The surface energy and water budgets are simulated with the SVS (Soil, Vegetation, and Snow) Land-Surface Scheme (LSS) at 2.5-km grid spacing over Canada. The routing component is based on the Watroute routing scheme at 1-km grid spacing for the Great Lakes and Nelson River watersheds. The system is run in two distinct phases: an analysis part and a forecast part. During the analysis part, CaLDAS outputs are used to force the routing system, which performs streamflow assimilation. In forecast mode, the surface component is forced with the Canadian GEM atmospheric forecasts and is initialized with a CaLDAS analysis. Streamflow performances of this new system are presented over 2019. Performances are compared to the current ECCC’s operational streamflow forecasting system, which is different from the new experimental system in many aspects. These new streamflow forecasts are also compared to persistence. Overall, the new streamflow forecasting system presents promising results, highlighting the need for an elaborated assimilation phase before performing the forecasts. However, the system is still experimental and is continuously being improved. Some major recent improvements are presented here and include, for example, the assimilation of snow cover data from remote sensing, a backward propagation of assimilated flow observations, a new numerical scheme for the routing component, and a new reservoir model.

Keywords: assimilation system, distributed physical model, offline hydro-meteorological chain, short-term streamflow forecasts

Procedia PDF Downloads 135

Authors: Parvin Abedi, Poorandokht Afshari

Abstract:

Introduction: In 2022, the Youth Law of the Population was notified to all organizations, including the Iranian Ministry of Health. Some of the articles of this law are about the role of midwives in health and treatment to promote childbearing. In this regard, articles number 45, 48, 49, and 50 are related to midwifery work that will be reviewed in this article. Methods: In this review, the law of population youth was reviewed. In this regard, the statistics of midwives working in the treatment and health sector were collected and analyzed according to the population youth law. Results: Nearly 47 000 midwives are working in the public and private sectors of the country and in the healthcare sector; according to Article 49, which states that there should be one midwife for every two parturient women, about 12,000 midwives are needed in the treatment department and about 8,000 midwives are needed in the health department. In Article 50 it is mentioned to modify tariffs and efficiency in order to increase natural childbirth, and in this field, insurance organizations should have sufficient cooperation with payments. The tariff for midwifery services has been increased, but it is not enough for the stressful job of midwifery. The labor incentive for delivery by midwives is also low. Conclusion: Midwives are one of the fundamental pillars of the law of the population, and without increasing the motivation of midwives, it is not possible to increase the rate of natural childbirth and make childbirth pleasant.

Keywords: law of the population, midwife, motivation, childbearing

Procedia PDF Downloads 49

Authors: Hammadi Larbi

Abstract:

The treatment of wastewater in sewage plants usually results in the formation of a large amount of sludge. These appear at the outlet of the treatment plant as a viscous fluid loaded with a high concentration of dry matter. This sludge production presents environmental, ecological, and economic risks. That is why it is necessary to find many solutions for minimizing these risks. In the present article, the effect of hydrogen peroxide, thermal treatment, and quicklime on the characteristics of the activated sludge produced in urban wastewater plant were evaluated in order to avoid any risk in the plants. The study shows increasing of the dose of H2O2 from 0 to 0.4 g causes an increase in the solubilization rate of COD from 12% to 45% and a reduction in the organic matter content of sludge (VM/SM) from 74% to 36% . The results also show that the optimum efficiency of the heat treatment corresponds to a temperature of 80 ° C for a treatment time of 40 min is 47% and 51.82% for a temperature equal to 100 ° C and 76.30 % for a temperature of 120 ° C, and 79.38% for a temperature of 140 ° C. The treatment of sludge by quicklime gives the optimum efficiency of 70.62 %. It was shown the increasing of the temperature from 80°C to 140°C, the pH of sludge was increased from 7.12 to 9.59. The obtained results showed that with increasing the dose of quicklime from 0 g/l to 1g/l in activated sludge led to an increase of their pH from 7.12 to 12.06. The study shows the increasing the dose of quicklime from 0 g/l to 1g/l causes also an increase in the solubilization of COD from 0% to 70.62 %

Keywords: activated sludge, hydrogen peroxide, thermal treatment, quicklime

Procedia PDF Downloads 109

Authors: Michael Sunday Afolayan

Abstract:

This research work examined the challenges bedevilling the development of legal framework for electronic commercial transactions (e-commerce) in Nigeria. Nigeria does not have a clear-cut legislation regulating electronic commerce in its jurisdiction despite the geometrical rate of growth and adoption of this method of trade. It specifically posed a great challenge looking at taxation, evidential and jurisdictional issues in e-commerce in Nigeria. The author in a broader research work which is abridged here, traced the origin and development of e-commerce and the attendant laws applicable in Nigeria, examining their sufficiency or otherwise. In carrying out the research work, doctrinal mode of legal research was adopted, examining both primary and secondary sources of legal research materials within their contextual meanings. It was found that the failure to enact a law which has direct regulatory bearing on e-commerce in Nigeria has led to adoption and application of circumstantial laws, rules and common law principles to tackle the problems arising out of electronic commercial transactions, especially in the areas of taxation, evidential and jurisdictional challenges. It was ultimately suggested that there is urgent need to sign into law, the Electronic Transaction Bill which had already been passed by the National Assembly since 2017.

Keywords: e-commerce, legislation, taxation, evidential, jurisdiction

Procedia PDF Downloads 90

Authors: Ankur Chaudhuri, Sibani Sen Chakraborty

Abstract:

In human, glutaminyl cyclase activity is highly abundant in neuronal and secretory tissues and is preferentially restricted to hypothalamus and pituitary. The N-terminal modification of β-amyloids (Aβs) peptides by the generation of a pyro-glutamyl (pGlu) modified Aβs (pE-Aβs) is an important process in the initiation of the formation of neurotoxic plaques in Alzheimer’s disease (AD). This process is catalyzed by glutaminyl cyclase (QC). The expression of QC is characteristically up-regulated in the early stage of AD, and the hallmark of the inhibition of QC is the prevention of the formation of pE-Aβs and plaques. A computer-aided drug design (CADD) process was employed to give an idea for the designing of potentially active compounds to understand the inhibitory potency against human glutaminyl cyclase (QC). This work elaborates the ligand-based and structure-based pharmacophore exploration of glutaminyl cyclase (QC) by using the known inhibitors. Three dimensional (3D) quantitative structure-activity relationship (QSAR) methods were applied to 154 compounds with known IC50 values. All the inhibitors were divided into two sets, training-set, and test-sets. Generally, training-set was used to build the quantitative pharmacophore model based on the principle of structural diversity, whereas the test-set was employed to evaluate the predictive ability of the pharmacophore hypotheses. A chemical feature-based pharmacophore model was generated from the known 92 training-set compounds by HypoGen module implemented in Discovery Studio 2017 R2 software package. The best hypothesis was selected (Hypo1) based upon the highest correlation coefficient (0.8906), lowest total cost (463.72), and the lowest root mean square deviation (2.24Å) values. The highest correlation coefficient value indicates greater predictive activity of the hypothesis, whereas the lower root mean square deviation signifies a small deviation of experimental activity from the predicted one. The best pharmacophore model (Hypo1) of the candidate inhibitors predicted comprised four features: two hydrogen bond acceptor, one hydrogen bond donor, and one hydrophobic feature. The Hypo1 was validated by several parameters such as test set activity prediction, cost analysis, Fischer's randomization test, leave-one-out method, and heat map of ligand profiler. The predicted features were then used for virtual screening of potential compounds from NCI, ASINEX, Maybridge and Chembridge databases. More than seven million compounds were used for this purpose. The hit compounds were filtered by drug-likeness and pharmacokinetics properties. The selective hits were docked to the high-resolution three-dimensional structure of the target protein glutaminyl cyclase (PDB ID: 2AFU/2AFW) to filter these hits further. To validate the molecular docking results, the most active compound from the dataset was selected as a reference molecule. From the density functional theory (DFT) study, ten molecules were selected based on their highest HOMO (highest occupied molecular orbitals) energy and the lowest bandgap values. Molecular dynamics simulations with explicit solvation systems of the final ten hit compounds revealed that a large number of non-covalent interactions were formed with the binding site of the human glutaminyl cyclase. It was suggested that the hit compounds reported in this study could help in future designing of potent inhibitors as leads against human glutaminyl cyclase.

Keywords: glutaminyl cyclase, hit lead, pharmacophore model, simulation

Procedia PDF Downloads 134

Authors: Malgorzata Krysiak, Anna Wegrzyn, Maciej Garstka, Radoslaw Mazur

Abstract:

Under constantly fluctuating environmental conditions, the thylakoid membrane protein network evolved the ability to dynamically respond to changing biotic and abiotic factors. One of the most important protective mechanism is rearrangement of the chlorophyll-protein (CP) complexes, induced by protein phosphorylation. In a temperate climate, low temperature is one of the abiotic stresses that heavily affect plant growth and productivity. The aim of this study was to determine the role of LHCII antenna complex phosphorylation in the dark-chilling response. The study included an experimental model based on dark-chilling at 4 °C of detached chilling sensitive (CS) runner bean (Phaseolus coccineus L.) and chilling tolerant (CT) garden pea (Pisum sativum L.) leaves. This model is well described in the literature as used for the analysis of chilling impact without any additional effects caused by light. We examined changes in thylakoid membrane protein phosphorylation, interactions between phosphorylated LHCII (P-LHCII) and CP complexes, and their impact on the dynamics of photosystem II (PSII) under dark-chilling conditions. Our results showed that the dark-chilling treatment of CS bean leaves induced a substantial increase of phosphorylation of LHCII proteins, as well as changes in CP complexes composition and their interaction with P-LHCII. The PSII photochemical efficiency measurements showed that in bean, PSII is overloaded with light energy, which is not compensated by CP complexes rearrangements. On the contrary, no significant changes in PSII photochemical efficiency, phosphorylation pattern and CP complexes interactions were observed in CT pea. In conclusion, our results indicate that different responses of the LHCII phosphorylation to chilling stress take place in CT and CS plants, and that kinetics of LHCII phosphorylation and interactions of P-LHCII with photosynthetic complexes may be crucial to chilling stress response. Acknowledgments: presented work was financed by the National Science Centre, Poland grant No.: 2016/23/D/NZ3/01276

Keywords: LHCII, phosphorylation, chilling stress, pea, runner bean

Procedia PDF Downloads 145

Authors: Tonga Agadi Danladi, Ajao Wasiu Bamidele, Terdue Dyeko

Abstract:

Recent advancement in microwave communications technologies especially in telecommunications and broadcasting have resulted in congestion on the frequencies below 10GHz. This has forced microwave designers to look for high frequencies. Unfortunately for frequencies greater than 10GHz rain becomes one of the main factors of attenuation in signal strength. At frequencies from 10GHz upwards, rain drop sizes leads to outages that compromises the availability and quality of service this making it a critical factor in satellite link budget design. Rain rate and rain attenuation predictions are vital steps to be considered when designing microwave satellite communication link operating at Ku-band frequencies (112-18GHz). Unreliable rain rates data in the tropical regions of the world like Nigeria from radio communication group of the international Telecommunication Union (ITU-R) makes it difficult for microwave engineers to determine a realistic rain margin that needs to be accommodated in satellite link budget design in such region. This work presents an empirical tool for predicting the amount of signal due to rain on DBS signal operating at the Ku-band.

Keywords: attenuation, Ku-Band, microwave communication, rain rates

Procedia PDF Downloads 489

Authors: Issa Qabaja, Fadi Thabtah

Abstract:

Email phishing classification is one of the vital problems in the online security research domain that have attracted several scholars due to its impact on the users payments performed daily online. One aspect to reach a good performance by the detection algorithms in the email phishing problem is to identify the minimal set of features that significantly have an impact on raising the phishing detection rate. This paper investigate three known feature selection methods named Information Gain (IG), Chi-square and Correlation Features Set (CFS) on the email phishing problem to separate high influential features from low influential ones in phishing detection. We measure the degree of influentially by applying four data mining algorithms on a large set of features. We compare the accuracy of these algorithms on the complete features set before feature selection has been applied and after feature selection has been applied. After conducting experiments, the results show 12 common significant features have been chosen among the considered features by the feature selection methods. Further, the average detection accuracy derived by the data mining algorithms on the reduced 12-features set was very slight affected when compared with the one derived from the 47-features set.

Keywords: data mining, email classification, phishing, online security

Procedia PDF Downloads 438

Authors: Xu Han, Shanxiong Chen, Shiyu Zhu, Xiaoyu Lin, Fujia Zhao, Dingwang Wang

Abstract:

Character detection is an important issue for character recognition of ancient Yi books. The accuracy of detection directly affects the recognition effect of ancient Yi books. Considering the complex layout, the lack of standard typesetting and the mixed arrangement between images and texts, we propose a character detection method for ancient Yi books based on connected components and regressive character segmentation. First, the scanned images of ancient Yi books are preprocessed with nonlocal mean filtering, and then a modified local adaptive threshold binarization algorithm is used to obtain the binary images to segment the foreground and background for the images. Second, the non-text areas are removed by the method based on connected components. Finally, the single character in the ancient Yi books is segmented by our method. The experimental results show that the method can effectively separate the text areas and non-text areas for ancient Yi books and achieve higher accuracy and recall rate in the experiment of character detection, and effectively solve the problem of character detection and segmentation in character recognition of ancient books.

Keywords: CCS concepts, computing methodologies, interest point, salient region detections, image segmentation

Procedia PDF Downloads 137

Authors: Kankurize Josiane, Nizigama Mediatrice

Abstract:

Introduction: Burundi records a still high infant mortality rate. Despite efforts to reduce it, prematurity is still the leading cause of death in the neonatal period. The objective of this study was to assess the quality of care for premature babies hospitalized in the neonatology unit of the Centre Hospitalier Universitaire de Kamenge. Method: This was a descriptive and evaluative prospective carried out in the neonatology unit of the CHUK (Centre Hospitalier Universitaire de Kamenge) from December 1, 2016, to May 31, 2017, including 70 premature babies, 65 mothers of premature babies and 15 providers including a pediatrician and 14 nurses. Using a tool developed by the World Health Organization and adapted to the local context by national experts, the quality of care for premature babies was assessed. Results: Prematurity accounted for 44.05% of hospitalizations in neonatology at the University Hospital of Kamenge. The assessment of the quality of care for premature babies was of low quality, with an average global score of 2/5 (50%), indicating that there is a considerable need for improvement to reach the standards. Conclusion: Efforts must be made to have infrastructures, materials, and human resources sufficient in quality and quantity so that the neonatology unit of the CHUK can be efficient and optimize the care of premature babies.

Keywords: quality of care, evaluation, premature, standards

Procedia PDF Downloads 69

Authors: Yang Li, Mingkai Liu, Qiong Rao, Zhongrui Gai, Ying Pan, Hongguang Jin

Abstract:

Hydrogen is an ideal and potential energy carrier due to its high energy efficiency and low pollution. An alternative and promising approach to hydrogen generation is the chemical looping steam reforming of methane (CL-SRM) over iron-based oxygen carriers. However, the process faces challenges such as high reaction temperature (>850 ℃) and low methane conversion. We demonstrate that Ni-mixed Fe-based oxygen carrier particles have significantly improved the methane conversion and hydrogen production rate in the range of 450-600 ℃ under atmospheric pressure. The effect on the reaction reactivity of oxygen carrier particles mixed with different Ni-based particle mass ratios has been determined in the continuous unit. More than 85% of methane conversion has been achieved at 600 ℃, and hydrogen can be produced in both reduction and oxidation steps. Moreover, the iron-based oxygen carrier particles exhibited good cyclic performance during 150 consecutive redox cycles at 600 ℃. The mid-temperature iron-based oxygen carrier particles, integrated with a moving-bed chemical looping system, might provide a powerful approach toward more efficient and scalable hydrogen production.

Keywords: chemical looping, hydrogen production, mid-temperature, oxygen carrier particles

Procedia PDF Downloads 148

Authors: Md. Asif Ullah, M. A. R. Sarkar

Abstract:

This paper illustrates 2-D and 3-D simulations of sub-channels of a Pressurized Water Reactor (PWR) having hexagonal array of fuel rods. At a steady state, the temperature of outer surface of the cladding of fuel rod is kept about 1200°C. The temperature of this isothermal surface is taken as boundary condition for simulation. Water with temperature of 290°C is given as a coolant inlet to the primary water circuit which is pressurized upto 157 bar. Turbulent flow of pressurized water is used for heat removal. In 2-D model, temperature, velocity, pressure and Nusselt number distributions are simulated in a vertical sectional plane through the sub-channels of a hexagonal fuel rod assembly. Temperature, Nusselt number and Y-component of convective heat flux along a line in this plane near the end of fuel rods are plotted for different Reynold’s number. A comparison between X-component and Y-component of convective heat flux in this vertical plane is analyzed. Hexagonal fuel rod assembly has three types of sub-channels according to geometrical shape whose boundary conditions are different too. In 3-D model, temperature, velocity, pressure, Nusselt number, total heat flux magnitude distributions for all the three sub-channels are studied for a suitable Reynold’s number. A horizontal sectional plane is taken from each of the three sub-channels to study temperature, velocity, pressure, Nusselt number and convective heat flux distribution in it. Greater values of temperature, Nusselt number and Y-component of convective heat flux are found for greater Reynold’s number. X-component of convective heat flux is found to be non-zero near the bottom of fuel rod and zero near the end of fuel rod. This indicates that the convective heat transfer occurs totally along the direction of flow near the outlet. As, length to radius ratio of sub-channels is very high, simulation for a short length of the sub-channels are done for graphical interface advantage. For the simulations, Turbulent Flow (K-Є ) module and Heat Transfer in Fluids (ht) module of COMSOL MULTIPHYSICS 5.0 are used.

Keywords: sub-channels, Reynold’s number, Nusselt number, convective heat transfer

Procedia PDF Downloads 363

Authors: Carolina Payares-Asprino

Abstract:

Dual-phase duplex stainless steel comprised of ferrite and austenite has shown high strength and corrosion resistance in many aggressive environments. Joining duplex alloys is challenging due to several embrittling precipitates and metallurgical changes during the welding process. The welding parameters strongly influence the quality of a weld joint. Therefore, it is necessary to quantify the weld bead’s integral properties as a function of welding parameters, especially when part of the weld bead is removed through a machining process due to aesthetic reasons or to couple the elements in the in-service structure. The present study uses the existing stress-strain model to predict the stress-strain curves for duplex stainless-steel welds under different welding conditions. Having mathematical expressions that predict the shape of the stress-strain curve is advantageous since it reduces the experimental work in obtaining the tensile test. In analysis and design, such stress-strain modeling simplifies the time of operations by being integrated into calculation tools, such as the finite element program codes. The elastic zone and the plastic zone of the curve can be defined by specific parameters, generating expressions that simulate the curve with great precision. There are empirical equations that describe the stress-strain curves. However, they only refer to the stress-strain curve for the stainless steel, but not when the material is under the welding process. It is a significant contribution to the applications of duplex stainless steel welds. For this study, a 3x3 matrix with a low, medium, and high level for each of the welding parameters were applied, giving a total of 27 weld bead plates. Two tensile specimens were manufactured from each welded plate, resulting in 54 tensile specimens for testing. When evaluating the four models used to predict the stress-strain curve in the welded specimens, only one model (Rasmussen) presented a good correlation in predicting the strain stress curve.

Keywords: duplex stainless steels, modeling, stress-stress curve, tensile test, welding

Procedia PDF Downloads 173

Authors: G. Judakova, M. Bause

Abstract:

The ability to model and simulate numerically natural gas flow in pipelines has become of high importance for the design of pipeline systems. The understanding of the formation of hydrate particles and their dynamical behavior is of particular interest, since these processes govern the operation properties of the systems and are responsible for system failures by clogging of the pipelines under certain conditions. Mathematically, natural gas flow can be described by multiphase flow models. Using the two-fluid modeling approach, the gas phase is modeled by the compressible Euler equations and the particle phase is modeled by the pressureless Euler equations. The numerical simulation of compressible multiphase flows is an important research topic. It is well known that for nonlinear fluxes, even for smooth initial data, discontinuities in the solution are likely to occur in finite time. They are called shock waves or contact discontinuities. For hyperbolic and singularly perturbed parabolic equations the standard application of the Galerkin finite element method (FEM) leads to spurious oscillations (e.g. Gibb's phenomenon). In our approach, we use stabilized FEM, the streamline upwind Petrov-Galerkin (SUPG) method, where artificial diffusion acting only in the direction of the streamlines and using a special treatment of the boundary conditions in inviscid convective terms, is added. Numerical experiments show that the numerical solution obtained and stabilized by SUPG captures discontinuities or steep gradients of the exact solution in layers. However, within this layer the approximate solution may still exhibit overshoots or undershoots. To suitably reduce these artifacts we add a discontinuity capturing or shock capturing term. The performance properties of our numerical scheme are illustrated for two-phase flow problem.

Keywords: two-phase flow, gas-particle mixture, inviscid two-fluid model, euler equation, finite element method, streamline upwind petrov-galerkin, shock capturing

Procedia PDF Downloads 315

Authors: P. V. Krupakara

Abstract:

This paper deals with the high corrosion resistance developed by the hybrid metal matrix composites when compared with that of matrix alloy. Matrix selected is Al6061. Reinforcements selected are graphite and red mud particulates. The composites are prepared using liquid melt metallurgy technique using vortex method. Metal matrix composites containing 2 percent graphite and 2 percent red mud, 2 percent graphite and 4 percent red mud, 2 percent graphite and 6 percent of red mud are prepared. Bar castings are cut into cylindrical discs of 20mm diameter and 20mm thickness. Corrosion tests were conducted at room temperature (230 °C) using conventional weight loss method according to ASTM G69-80. The corrodents used for the test were hydrochloric acid solution of different concentrations. Specimens were tested for every 24 hours interval up to 96 hours. Four specimens for each condition and time were immersed in corrodent. In each case the corrosion rate decreases with increase in exposure time for matrix and metal matrix composites whatever may be the concentration of hydrochloric acid. This may be due to aluminium, which may induce passivation due to development of non-porous layer. As red mud content increases the composites become corrosion resistant due to insulating nature of ceramic material red mud and less exposure of matrix alloy in those metal matrix composites.

Keywords: Al6061, graphite, passivation, red mud, vortex

Procedia PDF Downloads 545

Authors: Megha Rao, Søren H. Jensen, Xiufu Sun, Anke Hagen, Mogens B. Mogensen

Abstract:

Solid oxide electrolysis cells have an immense potential in converting CO₂ and H₂O into syngas during co-electrolysis operation. The produced syngas can be further converted into hydrocarbons. This kind of technology is called power-to-gas or power-to-liquid. To produce hydrocarbons via this route, durability of the cells is still a challenge, which needs to be further investigated in order to improve the cells. In this work, various nickel-yttria stabilized zirconia (Ni-YSZ) fuel electrode supported or YSZ electrolyte supported cells, cerium gadolinium oxide (CGO) barrier layer, and an oxygen electrode are investigated for durability under co-electrolysis conditions in both galvanostatic and potentiostatic conditions. While changing the gas on the oxygen electrode, keeping the fuel electrode gas composition constant, a change in the gas concentration arc was observed by impedance spectroscopy. Measurements of open circuit potential revealed the presence of leaks in the setup. It is speculated that the change in concentration impedance may be related to the leaks. Furthermore, the cells were also tested under pressurized conditions to find an inter-play between the leak rate and the pressure. A mathematical modeling together with electrochemical and microscopy analysis is presented.

Keywords: co-electrolysis, durability, leaks, gas concentration arc

Procedia PDF Downloads 151

Authors: Kerri L. Surbaugh, Lakmini Y. Mallikarachchi, Jason R. Rohr

Abstract:

Emerging diseases are key factors in the disconcerting rate of contemporary amphibian declines. The chytrid fungus, Batrachochytrium dendrobatidis (Bd), ranks among the chief pathogenic challenges to vulnerable amphibian populations. Although live Bd can immunosuppress amphibian hosts, amphibian exposure to dead Bd can induce an adaptive immune response, leading to acquired resistance to the pathogen. In this experiment, dose and duration of flash-frozen Bd were manipulated over a variety of life-stages of the Cuban treefrog (Osteopilus septentrionalis) and the magnitude of acquired resistance to the pathogen was quantified via qPCR analyses of spore abundance post subsequent live Bd challenges. It was found that Cuban treefrogs can develop resistance to Bd and that life stage, dose and duration thresholds exist for acquired resistance. This experiment will aid in facilitating the development of a vaccine against Bd which could be used on location and could help curb worldwide amphibian declines associated with this pathogen.

Keywords: acquired resistance, ecoimmunology, emerging infectious disease, fungal host response, fungal pathogen, immunization

Procedia PDF Downloads 137

Authors: Peng Li, Luan Wang, Haifeng Fei, Renhong Xie, Yibin Rui, Shanhong Guo

Abstract:

The applications of satellite-based automatic identification system (S-AIS) pave the road for wide-range maritime traffic monitoring and management. But the coverage of satellite’s view includes multiple AIS self-organizing networks, which leads to the collision of AIS signals from different cells. The contribution of this work is to propose an improved multi-channel blind source separation algorithm based on Artificial Bee Colony (ABC) and advanced stochastic optimization to perform separation of the mixed AIS signals. The proposed approach adopts modified ABC algorithm to get an optimized initial separating matrix, which can expedite the initialization bias correction, and utilizes the Adaptive Moment Estimation (Adam) to update the separating matrix by adjusting the learning rate for each parameter dynamically. Simulation results show that the algorithm can speed up convergence and lead to better performance in separation accuracy.

Keywords: satellite-based automatic identification system, blind source separation, artificial bee colony, adaptive moment estimation

Procedia PDF Downloads 190

Authors: N. Ouslimani, M. T. Abadlia

Abstract:

Environment protection is a precondition for sustained growth and a better quality of life for all people on earth. Aqueous industrial effluents are the main sources of pollution. Among the compounds of these effluents, dyes are particularly resistant to discoloration by conventional methods, and discharges present many problems that must be supported. The scientific literature shows that synthetic organic dyes are compounds used in many industrial sectors. They are found in the chemical, car, paper industry and particularly the textile industry, where all the lines and grades of the chemical family are represented. The affinity between the fibers and dyes vary depending on the chemical structure of dyes and the type of materials to which they are applied. It is not uncommon to find that during the dyeing operation from 15 to 20 % of sulfur dyes, and sometimes up to 40 % of the reactants are discharged with the effluent. This study was conducted for the purpose of fading basics dyes from wastewater using as adsorbent fiber waste material. This technique presents an interesting alternative to usual treatment, as it allows the recovery of waste fibers, which can find uses as raw material for the manufacture of cleaning products or in other sectors In this study the results obtained by fading fiber waste are encouraging, given the rate of color removal which is about 90%.This method also helps to decrease BOD and suspended solids MES in an effective way.

Keywords: adsorption, dyes, fiber, valorization, wastewater

Procedia PDF Downloads 293

Authors: Noor-ul-Ain, Muhammad Tahir Khan, Kashif Khan, Adeela Ajmal, Hamid Mustafa

Abstract:

The objective of this study was to evaluate the preservative and upgrading potential of urea (70g/kg DM) added to high moisture oat silage at laboratory scale trial and urea was hydrolysed 95%. Microbial activity measured by pH and volatile fatty acids (VFA) and lactate production was reduced (p<0.001) by the urea addition. The pH of oat silage (without treated) was measured 5.7 and increased up to 8.00 on average while; volatile fatty acids (VFA) concentration was decreased. Relative proportions of fermentation acids changed after urea addition, increasing the acetate and butyrate and decreasing the propionate and lactate proportions. The addition of urea to oat silages increased (P<0.001) water soluble and ammonium nitrogen of the forage. These nitrogen fractions represented more than 40% of total nitrogen. After urea addition, total nitrogen content of oat silages increased from 21.0 g/kg DM to 28 g/kg DM. Application of urea at a rate of 70 g/kg DM significantly increased (P<0.001) the in situ degradation of neutral-detergent fibre after 48h of rumen incubation (NDF-situ). The NDF-situ was 200 g/kg NDF higher on oat forages ensiled with urea than on oat forages ensiled without urea. Oat silages can be effectively preserved and upgraded by ensiling with 70 g urea/kg dry matter. Further studies are required to evaluate voluntary intake of this forage.

Keywords: oat, silage, urea, pH, forage

Procedia PDF Downloads 473

Authors: Illyas Md Isa, Sharifah Norain Mohd Sharif, Norhayati Hashim

Abstract:

A mercury(II) sensor was developed by using multi-walled carbon nano tubes (MWCNTs) paste electrode modified with Zn/Al layered double hydroxide-3(4-methoxyphenyl) propionate nano composite (Zn/Al-HMPP). The optimum conditions by cyclic voltammetry were observed at electrode composition 2.5% (w/w) of Zn/Al-HMPP/MWCNTs, 0.4 M potassium chloride, pH 4.0, and scan rate of 100 mVs-1. The sensor exhibited wide linear range from 1x10-3 M to 1x10-7 M Hg2+ and 1x10-7 M to 1x10-9 M Hg2+, with a detection limit of 1 x 10-10 M Hg2+. The high sensitivity of the proposed electrode towards Hg(II) was confirmed by double potential-step chronocoulometry which indicated these values; diffusion coefficient 1.5445 x 10-9 cm2 s-1, surface charge 524.5 µC s-½ and surface coverage 4.41 x 10-2 mol cm-2. The presence of 25-fold concentration of most metal ions had no influence on the anodic peak current. With characteristics such as high sensitivity, selectivity and repeatability the electrode was then proposed as the appropriate alternative for the determination of mercury.

Keywords: Cyclic voltammetry, Mercury(II), Modified carbon paste electrode, Nanocomposite

Procedia PDF Downloads 435

Authors: Dechrit Maneetham

Abstract:

Pick and place task is one among the most important tasks in industrial field handled by 'Selective Compliance Assembly Robot Arm' (SCARA). Repeatability with high-speed movement in a horizontal plane is a remarkable feature of this type of manipulator. The challenge of design SCARA is the difficulty of achieving stability of high-speed movement with the long length of links. Shorter links arm can move more stable. This condition made the links should be considered restrict then followed by restriction of operation area (workspace). In this research, authors demonstrated on expanding SCARA robot’s workspace in horizontal area via linear sliding actuator that embedded to base link of the robot arm. With one additional prismatic joint, the previous robot manipulator with 3 degree of freedom (3-DOF), 2 revolute joints and 1 prismatic joint becomes 4-DOF PRRP manipulator. This designation increased workspace of robot from 0.5698m² performed by the previous arm (without linear actuator) to 1.1281m² by the proposed arm (with linear actuator). The increasing rate was about 97.97% of workspace with the same links' lengths. The result of experimentation also indicated that the operation time spent to reach object position was also reduced.

Keywords: kinematics, linear sliding actuator, manipulator, control system

Procedia PDF Downloads 265