Search results for: external pressures

Authors: Li̇zan Mahmood Khorsheed Zangana

Abstract:

Experimental and numerical investigations have been carried out to study the mechanism of separation energy and flow phenomena in the counter-flow vortex tube. This manuscript presents a complete comparison between the experimental investigation and CFD analysis. The experimental model tested under different inlet pressures. Three-dimensional numerical modelling using the k-ε model. The results show any increase in both cold mass fraction and inlet pressure caused to increase ΔTc, and the maximum ΔTc value occurs at P = 6 bar. The coefficient of performance (COP) of two important factors in the vortex tube have been evaluated, which ranged from 0.25 to 0.74. The maximum axial velocity is 93, where it occurs at the tube axis close the inlet exit (Z/L=0.2). The results showed a good agreement for experimental and numerical analysis.

Keywords: counter flow, vortex tube, computational fluid dynamics analysis, energy separation, experimental study

Procedia PDF Downloads 58

Authors: Emmanuel Mkambankhani, Tiwonge Manda

Abstract:

Software platform architecture includes system components, their relationships, and design, as well as evolution principles. Software architecture and documentation affect a platform's customizability and openness to external innovators, thus affecting developer productivity. Malawi Point of Care (POC) Electronic Medical Records System (EMRS) follows some architectural design standards, but it lacks third-party innovators and is difficult to customize as compared to CommCare and District Health Information System 2 (DHIS2). Improving software architecture and documentation for the Malawi POC will increase productivity and third-party contributions. A conceptual framework based on Generativity and Boundary Resource Model (BRM) was used to compare the three platforms. Interviews, observations, and document analysis were used to collect primary and secondary data. Themes were found by analyzing qualitative and quantitative data, which led to the following results. Configurable, flexible, and cross-platform software platforms and the availability of interfaces (Boundary Resources) that let internal and external developers interact with the platform's core functionality, hence boosting developer productivity. Furthermore, documentation increases developer productivity, while its absence inhibits the use of resources. The study suggests that the architecture and openness of the Malawi POC EMR software platform will be improved by standardizing web application program interfaces (APIs) and making interfaces that can be changed by the user. In addition, increasing the availability of documentation and training will improve the use of boundary resources, thus improving internal and third-party development productivity.

Keywords: health systems, configurable platforms, software architecture, software documentation, software development productivity

Procedia PDF Downloads 73

Authors: Meza-Quintero Myriam, Lobo Torrado Katty Andrea, Sanchez Picon Yesenia, Hurtado-Lugo Naudin

Abstract:

The objective of the study was to evaluate the internal and external quality of the egg in the three production housing systems: floor, cage, and grazing of laying birds of the Isa Brown line, in the laying period between weeks 35 to 41; 135 hens distributed in 3 treatments of 45 birds per repetition were used (the replicas were the seven weeks of the trial). The feeding treatment supplied in the floor and cage systems contained 114 g/bird/day; for the grazing system, 14 grams less concentrate was provided. Nine eggs were collected to be studied and analyzed in the animal nutrition laboratory (3 eggs per housing system). The random statistical model was implemented: for the statistical analysis of the data, the statistical software of IBM® Statistical Products and Services Solution (SPSS) version 2.3 was used. The evaluation and follow-up instruments were the vernier caliper for the measurement in millimeters, a YolkFan™16 from Roche DSM for the evaluation of the egg yolk pigmentation, a digital scale for the measurement in grams, a micrometer for the measurement in millimeters and evaluation in the laboratory using dry matter, ashes, and ethereal extract. The results suggested that equivalent to the size of the egg (0.04 ± 3.55) and the thickness of the shell (0.46 ± 3.55), where P-Value> 0.05 was obtained, weight albumen (0.18 ± 3.55), albumen height (0.38 ± 3.55), yolk weight (0.64 ± 3.55), yolk height (0.54 ± 3.55) and for yolk pigmentation (1.23 ± 3.55). It was concluded that the hens in the three production systems, floor, cage, and grazing, did not show significant statistical differences in the internal and external quality of the chicken in the parameters studied egg for the production system.

Keywords: biological, territories, genetic resource, egg

Procedia PDF Downloads 67

Authors: Indrajeet Singh, Abhishek Gandhi, Smita Mohanty, S. K. Nayak

Abstract:

In this article, a focused study has been performed to comprehend the influence of change in depressurization rate on microcellular polycarbonate foamed morphological attributes. The depressurization rate considered in this study were 0.5, 0.05, 0.01 and 0.005 MPa/sec and the physical blowing agent utilized was carbon dioxide owing to its high solubility in polycarbonate at room temperature. The study was performed on two distinct saturation pressures, i.e., 3 MPa and 6 MPa to understand if saturation pressure has any effects on it. It is reported that with increase in depressurization rate, a higher amount of thermodynamic instability was induced which resulted in generation of larger number of smaller sized cells. This article puts forward an understanding of how depressurization rate control could be well exploited during the batch foaming process to develop high quality microcellular foamed products with exceedingly well controlled cell size.

Keywords: depressurization, porous polymer, foaming, microcellular

Procedia PDF Downloads 246

Authors: Boy Arief Fachri

Abstract:

Even its content is rich in antioxidants ϒ-oryzanol, rice bran is not used properly as functional food. This research aims to (1) extract ϒ-oryzanol; (2) determine the solubility of ϒ-oryzanol in supercritical CO₂ based on phase equilibrium theory; and (3) study the effect of process variables on solubility. Extraction experiments were carried out for rice bran (5 g) at various extraction pressures, temperatures and reaction times. The flowrate of supercritical fluid through the extraction vessel was 25 g/min. The extracts were collected and analysed with high-pressure liquid chromatography (HPLC). The conclusion based on the experiments are as: (1) The highest experimental solubility was 0.303 mcg/mL RBO at T= 60°C, P= 90 atm, t= 30 min; (2) Solubility of ϒ-oryzanol was influenced by pressure and temperature. As the pressure and temperature increase, the solubility increases; (3) The solubility data of supercritical extraction can be successfully determined using phase equilibrium theory. Meanwhile, tocopherol was found and slightly investigated in this work.

Keywords: rice bran, solubility, supercritical CO2, ϒ-orizanol

Procedia PDF Downloads 358

Authors: Bahram Soltani, Louai Ghazieh

Abstract:

Following the high profile financial scandals of 2007-2008, corporate management has been faced with strong pressures resulting from more regulatory requirements, as well as the increasing expectations of various groups of stakeholders. The responsibility acquired a big importance in front of this financial crisis. This responsibility requires more transparency and communication, inside the company with the collaborators and outside of the company with the society, while companies try to improve the degree of control and to authorize managers to realize the objectives of the company. The objective of this paper is to present the concept of the responsibility generally and the various types of manager’s responsibility in private individual within the company, as well as the explanatory theories of this responsibility through the various perspectives such as: economic, political, social and behavioral. This study should have academic and practical contributions particularly for regulators seeking to improve the companies’ practices and organizational functioning within capital market economy.

Keywords: manager, accountability, corporate performance, financial crisis, behavior

Procedia PDF Downloads 377

Authors: Edoghogho Ogbeifun, Charles Mbohwa, J. H. C. Pretorius

Abstract:

Several research report on the factors responsible for the delays in the completion of construction projects has identified the issue of funding as a critical factor; insufficient funding, low cash-flow or lack of funds. Indeed, adequate funding plays pivotal role in the effective execution of construction projects. In the last twenty years (or so), there has been increase in the funds available for infrastructure development in tertiary institution in Nigeria, especially, through the Tertiary Education Trust Fund. This funding body ensures that there is enough fund for each approved project, which is released in three stages during the life of the construction project. However, a random tour of many of the institutions reveals striking evidence of projects not delivered on schedule, to quality and sometime out rightly abandoned. This suggests, therefore, that there are other latent factors, responsible for project delays, that should be investigated. Thus, this research, a pilot scheme, is aimed at unearthing the possible reasons for the delays being experienced in the execution of construction projects for infrastructure upgrade in public tertiary institutions in Nigeria, funded by Tertiary Education Trust Fund. The multiple site case study of qualitative research was adopted. The respondents were the Directors of Physical Planning and the Directors of Works of four Nigerian Public Universities. The findings reveal that delays can be situated within three entities, namely, the funding body, the institutions and others. Therefore, the emerging factors have been classified as external factors (haven to do with the funding body), internal factors (these concern the operations within the institutions) and general factors. The outcome of this pilot exercise provides useful information to guide the Directors as they interact with the funding body as well as challenges themselves to address the loopholes in their internal operations.

Keywords: delays, external factors, funding, general factors, Internal factors

Procedia PDF Downloads 126

Authors: Irina Mizeva, Elena Potapova, Viktor Dremin, Mikhail Mezentsev, Valeri Shupletsov

Abstract:

The local tissue perfusion is regulated by the microvascular tone which is under the control of a number of physiological mechanisms. Laser Doppler flowmetry (LDF) together with wavelet analyses is the most commonly used technique to study the regulatory mechanisms of cutaneous microcirculation. External factors such as temperature, local pressure of the probe on the skin, etc. influence on the blood flow characteristics and are used as physiological tests to evaluate microvascular regulatory mechanisms. Local probe pressure influences on the microcirculation parameters measured by optical methods: diffuse reflectance spectroscopy, fluorescence spectroscopy, and LDF. Therefore, further study of probe pressure effects can be useful to improve the reliability of optical measurement. During pressure tests variation of the mean perfusion measured by means of LDF usually is estimated. An additional information concerning the physiological mechanisms of the vascular tone regulation system in response to local pressure can be obtained using spectral analyses of LDF samples. The aim of the present work was to develop protocol and algorithm of data processing appropriate for study physiological response to the local pressure test. Involving 6 subjects (20±2 years) and providing 5 measurements for every subject we estimated intersubject and-inter group variability of response of both averaged and oscillating parts of the LDF sample on external surface pressure. The final purpose of the work was to find special features which further can be used in wider clinic studies. The cutaneous perfusion measurements were carried out by LAKK-02 (SPE LAZMA Ltd., Russia), the skin loading was provided by the originally designed device which allows one to distribute the pressure around the LDF probe. The probe was installed on the dorsal part of the distal finger of the index figure. We collected measurements continuously for one hour and varied loading from 0 to 180mmHg stepwise with a step duration of 10 minutes. Further, we post-processed the samples using the wavelet transform and traced the energy of oscillations in five frequency bands over time. Weak loading leads to pressure-induced vasodilation, so one should take into account that the perfusion measured under pressure conditions will be overestimated. On the other hand, we revealed a decrease in endothelial associated fluctuations. Further loading (88 mmHg) induces amplification of pulsations in all frequency bands. We assume that such loading leads to a higher number of closed capillaries, higher input of arterioles in the LDF signal and as a consequence more vivid oscillations which mainly are formed in arterioles. External pressure higher than 144 mmHg leads to the decrease of oscillating components, after removing the loading very rapid restore of the tissue perfusion takes place. In this work, we have demonstrated that local skin loading influence on the microcirculation parameters measured by optic technique; this should be taken into account while developing portable electronic devices. The proposed protocol of local loading allows one to evaluate PIV as far as to trace dynamic of blood flow oscillations. This study was supported by the Russian Science Foundation under project N 18-15-00201.

Keywords: blood microcirculation, laser Doppler flowmetry, pressure-induced vasodilation, wavelet analyses blood

Procedia PDF Downloads 132

Authors: Suzan Odabasi

Abstract:

Suicide attempts and mental health problems among immigrants have been increasing and have become important public health concerns during the last century. Immigrants may face more difficulties in society because of social conflict, language barriers, inadequate social support, socioeconomic problems, and delay in accessing help. The limited number of research has shown that: first-generation migrants may be at higher risk of mental disorders and a higher prevalence of suicide attempts. The main aim of the proposed work is to identify to what degree each of these pressures is causing higher suicides currently observed. In addition, a comparison will be conducted between females and males and also rural and urban areas for which recent data are available. Specifically, this study investigates how accessing mental health services, the uninsured population rate, socioeconomic factors, and being an immigrant affect Turkish immigrants’ mental health and suicide attempts.

Keywords: access to healthcare, immigration, health economics, mental health economics

Procedia PDF Downloads 84

Authors: Omar Alomoush

Abstract:

This paper examines the Armenian language in the linguistic landscape of Jordanian cities. The results indicate that Armenian is chiefly marginalised in the LL. By quantitative and qualitative methods, the current study attempts to identify the main reasons behind this marginalisation. In the light of the fact that Armenian is completely absent from the commercial streets of major Jordanian cities, all monolingual and multilingual signs in Armenian Neighbourhood in Amman city are photographed to identify them according to function and language. To provide plausible explanations for the marginalisation of the Armenian language in the LL, the current study builds upon issues of language maintenance and underlying language policy. According to the UNESCO Endangerment Framework, it can be assumed that Armenian is a vulnerable language, even though the Armenian Church exerted great efforts to revitalise Armenian in all social settings, including the LL. It was found that language policies enacted by the state of Jordan, language shift, language hostility, voluntary migration and economic pressures are among the reasons behind this marginalisation.

Keywords: linguistic landscape, multilingualism, Armenian, marginalisation and revitalisation

Procedia PDF Downloads 242

Authors: Hanen Bouaziz, Françoise Croute, Najiba Zeghal

Abstract:

In order to investigate the toxic effects of fluoride on cerebrum maturity of suckling mice, we treated adult female mice of Swiss Albinos strain by 500 ppm NaF in their drinking water from the 15th day of pregnancy until the day 14 after delivery. All mice were sacrificed on day 14 after parturition. During treatment, levels of thiobarbituric acid reactive substances, the marker of lipid peroxidation extend, increased, while the activities of the antioxidant enzymes such as glutathione peroxidase, superoxide dismutase and catalase and the level of glutathione decreased significantly in cerebellum compared with those of the control group. These results suggested that fluoride enhanced oxidative stress, thereby disturbing the antioxidant defense of nursing pups. In addition, acetylcholinesterase activity in cerebellum was inhibited after treatment with fluoride. In cerebellum of mice, migration of neurons from the external granular layer to the internal granular layer occurred postnatally. Key guidance signals to these migrating neurons were provided by laminin, an extracellular matrix protein fixed to the surface of astrocytes. In the present study, we examined the expression and distribution of laminin in cerebellum of 14-day-old mice. Immunoreactive laminin was disappeared by postnatal day 14 in cerebellum parenchyma of control pups and was restricted to vasculature despite the continued presence of granular cells in the external granular layer. In contrast, in cerebellum of NaF treated pups, laminin was deposited in organised punctuate clusters in the molecular layer. These data indicated that the disruption of laminin distribution might play a major role in the profound derangement of neuronal migration observed in cerebellum of NaF treated pups.

Keywords: acetylcholinesterase activity, cerebellum, laminin, oxidative stress, suckling mice

Procedia PDF Downloads 379

Authors: Adel Elomri

Abstract:

The notion of carbon footprinting is ever more widespread as companies are becoming increasingly aware that tackling carbon emissions and being seen to do so is a key issue to face governments, customers and other stakeholders’ pressures towards delivering environmentally friendly services and activities. In this contest, many firms are taking self-initiatives to reduce their own carbon emissions while some other are constrained to obey to different regulations/policies (e.g. carbon tax or carbon Cap) designed by higher authorities targeting a low-carbon environment. Using buyer-vendor framework, this paper provides some insights on how effective are these self-initiatives and regulatory policies when only concerning firms at the individual level and not the whole supply chain they are part of. We show that when firms individually engage in reducing their direct carbon emissions either under self-initiatives or regulatory policy, an opposite expected outcome resulting in a higher global supply chain emission can occur. This effect is referred to as the carbon seesaw effect. Moreover, we show that coordinating or centralizing the supply chain -contrary to what one may think at first- is not often the appropriate solution to get rid of this effect.

Keywords: carbon emissions, supply chain coordination, EOQ, sustainable operations

Procedia PDF Downloads 298

Authors: Iftikhar Ahmad, Youssef Elkezza

Abstract:

Sarir oilfield is in North Africa. It has facilities for oil and gas production. The assets of the Sarir oilfield can be divided into five following categories, namely: (i) well bore and wellheads; (ii) vessels such as separators, desalters, and gas processing facilities; (iii) pipelines including all flow lines, trunk lines, and shipping lines; (iv) storage tanks; (v) other assets such as turbines and compressors, etc. The nature of the petroleum industry recognizes the potential human, environmental and financial consequences that can result from failing to maintain the integrity of wellheads, vessels, tanks, pipelines, and other assets. The importance of effective asset integrity management increases as the industry infrastructure continues to age. The primary objective of assets integrity management (AIM) is to maintain assets in a fit-for-service condition while extending their remaining life in the most reliable, safe, and cost-effective manner. Corrosion management is one of the important aspects of successful asset integrity management. It covers corrosion mitigation, monitoring, inspection, and risk evaluation. External corrosion on pipelines, well bores, buried assets, and bottoms of tanks is controlled with a combination of coatings by cathodic protection, while the external corrosion on surface equipment, wellheads, and storage tanks is controlled by coatings. The periodic cleaning of the pipeline by pigging helps in the prevention of internal corrosion. Further, internal corrosion of pipelines is prevented by chemical treatment and controlled operations. This paper describes the integrity management system used in the Sarir oil field for its oil and gas production facilities based on standard practices of corrosion mitigation and inspection.

Keywords: assets integrity management, corrosion prevention in oilfield assets, corrosion management in oilfield, corrosion prevention, inspection activities

Procedia PDF Downloads 59

Authors: Raman Sharma, Ashok Kumar, Vipin Koushal

Abstract:

Healthcare facilities are always seen as places of haven and protection for managing the external incidents, but the situation becomes more difficult and challenging when such facilities themselves are affected from internal hazards. Such internal hazards are arguably more disruptive than external incidents affecting vulnerable ones, as patients are always dependent on supportive measures and are neither in a position to respond to such crisis situation nor do they know how to respond. The situation becomes more arduous and exigent to manage if, in case critical care areas like Intensive Care Units (ICUs) and Operating Rooms (OR) are convoluted. And, due to these complexities of patients’ in-housed there, it becomes difficult to move such critically ill patients on immediate basis. Healthcare organisations use different types of electrical equipment, inflammable liquids, and medical gases often at a single point of use, hence, any sort of error can spark the fire. Even though healthcare facilities face many fire hazards, damage caused by smoke rather than flames is often more severe. Besides burns, smoke inhalation is primary cause of fatality in fire-related incidents. The greatest cause of illness and mortality in fire victims, particularly in enclosed places, appears to be the inhalation of fire smoke, which contains a complex mixture of gases in addition to carbon monoxide. Therefore, healthcare organizations are required to have a well-planned disaster mitigation strategy, proactive and well prepared manpower to cater all types of exigencies resulting from internal as well as external hazards. This case report delineates a true OR fire incident in Emergency Operation Theatre (OT) of a tertiary care multispecialty hospital and details the real life evidence of the challenges encountered by OR staff in preserving both life and property. No adverse event was reported during or after this fire commotion, yet, this case report aimed to congregate the lessons identified of the incident in a sequential and logical manner. Also, timely smoke evacuation and preventing the spread of smoke to adjoining patient care areas by opting appropriate measures, viz. compartmentation, pressurisation, dilution, ventilation, buoyancy, and airflow, helped to reduce smoke-related fatalities. Henceforth, precautionary measures may be implemented to mitigate such incidents. Careful coordination, continuous training, and fire drill exercises can improve the overall outcomes and minimize the possibility of these potentially fatal problems, thereby making a safer healthcare environment for every worker and patient.

Keywords: healthcare, fires, smoke, management, strategies

Procedia PDF Downloads 51

Authors: Claudia H. Swanson, Jens Günster

Abstract:

This research addresses the densification via compaction and sintering of naturally occurring rock salt which was motivated by the fact that in a saline environment rock salt is thermodynamically stable and does show a mechanical behavior compatible to the surrounding host material. The sintering of rock salt powder compacts was systematically investigated using temperature and pressure as variables for the sinter process. The behavior of rock salt showed segregations of anhydrite, CaSO4 - the major impurity found in rock salt, to the grain boundaries between individual sodium chloride crystals. Powder compacts treated with lower pressures lost those anhydrite segregates over time while high pressure treated compacts remained with anhydrite segregates. The density reached in this study is 2.008 g cm-3 corresponding to a density of 92.5 % of the theoretical value. This high density is making the sintering a promising technique for rock salt as applications in underground appropriate environment.

Keywords: rock salt, sinter, anhydrite, nuclear safety

Procedia PDF Downloads 477

Authors: Mahdi Asghari

Abstract:

The cavitation phenomenon is the formation and production of micro-bubbles and eventually the bursting of the micro-bubbles inside the liquid fluid, which results in localized high pressure and temperature, causing physical and chemical fluid changes. This pressure and temperature are predicted to be 2000 atmospheres and 5000 °C, respectively. As a result of small bubbles bursting from this process, temperature and pressure increase momentarily and locally, so that the intensity and magnitude of these temperatures and pressures provide the energy needed to break the molecular bonds of heavy compounds such as fuel oil. In this paper, we study the theory of cavitation and the methods of cavitation production by acoustic and hydrodynamic methods and the necessary mechanical equipment and reactors for industrial application of the hydrodynamic cavitation method to break down the molecular bonds of the fuel oil and convert it into useful and economical products.

Keywords: Cavitation, Hydrodynamic Cavitation, Cavitation Reactor, Fuel Oil

Procedia PDF Downloads 103

Authors: K. Geetha Ramesh, A. Ramachandraiah

Abstract:

In an internal building space, daylight becomes a powerful source of illumination. The challenge therefore, is to develop means of utilizing both direct and diffuse natural light in buildings while maintaining and improving occupant's visual comfort, particularly at greater distances from the windows throwing daylight. The geometrical features of windows in a building have significant effect in providing daylight. The main goal of this research is to develop an innovative window geometry, which will effectively provide the daylight component adequately together with internal reflected component(IRC) and also the external reflected component(ERC), if any. This involves exploration of a light redirecting system using fractal geometry for windows, in order to penetrate and distribute daylight more uniformly to greater depths, minimizing heat gain and glare, and also to reduce building energy use substantially. Of late the creation of fractal geometrical window and the occurrence of daylight illuminance due to such windows is becoming an interesting study. The amount of daylight can change significantly based on the window geometry and sky conditions. This leads to the (i) exploration of various fractal patterns suitable for window designs, and (ii) quantification of the effect of chosen fractal window based on the relationship between the fractal pattern, size, orientation and glazing properties for optimizing daylighting. There are a lot of natural lighting applications able to predict the behaviour of a light in a room through a traditional opening - a regular window. The conventional prediction methodology involves the evaluation of the daylight factor, the internal reflected component and the external reflected component. Having evaluated the daylight illuminance level for a conventional window, the technical performance of a fractal window for an optimal daylighting is to be studied and compared with that of a regular window. The methodologies involved are highlighted in this paper.

Keywords: daylighting, fractal geometry, fractal window, optimization

Procedia PDF Downloads 288

Authors: Aniket Aaba Kadam, Manish Mangesh Panchal, Roushan Ashit Sharma

Abstract:

This project focuses on the design and development of a lab-scale hybrid rocket motor to accurately determine the regression rate of a fuel/oxidizer combination consisting of solid paraffin and gaseous oxygen (GOX). Hybrid motors offer the advantage of on-demand thrust control over both solid and liquid systems in certain applications. The thermodynamic properties of the propellant combination were calculated using NASA CEA at different chamber pressures and corresponding O/F values to determine initial operating conditions with suitable peak temperatures and optimal O/F values. The project also includes the design of the injector orifice and the determination of the final design configurations of the motor casing, pressure control setup, and valve configuration. This research will be valuable in advancing the understanding of paraffin-based propulsion and improving the performance of hybrid rocket motors.

Keywords: hybrid rocket, NASA CEA, injector, thrust control

Procedia PDF Downloads 81

Authors: G. De Matteis, L. Martina, V. Turco

Abstract:

The work is focused on determining and comparing special nonlinear static configurations in cholesteric liquid crystals (CLCs), confined between two parallel plates and in the presence of an external static electric/magnetic field. The solutions are stabilised by topological and non-topological conservation laws since they are described in terms of integrable or partially integrable nonlinear boundary value problems. In cholesteric liquid crystals which are subject to geometric frustration; anchoring conditions at boundaries, i.e., homeotropic conditions, are incompatible with the cholesteric twist. This aspect turns out to be essential in the admissible classes of solutions, allowing also for disclination type singularities. Within the framework of Frank-Oseen theory, we study the static configurations for CLCs. First, we find numerical solutions for isolated axisymmetric states in confined CLCs with weak homeotropic anchoring at the boundaries. These solutions describe 3-dimensional modulations, namely spherulites or cholesteric bubbles, actually observed in these systems, of standard baby skyrmions. Relations with well-known nonlinear integrable systems are found and are used to explore the asymptotic behavior of the solutions. Then we turn our attention to extended periodic static configurations called Helicoids or cholesteric fingers, described by an elliptic sine-Gordon model with appropriate boundary conditions, showing how their period and energies are determined by both the thickness of the cell and the intensity of the external electric/magnetic field. We explicitly show that helicoids with π or 2π of rotations of the molecular director are different in many aspects and are not simply algebraically related. The behaviour of the solutions, their energy and the properties of the associated disclinations are discussed in detail, both analytically and numerically.

Keywords: cholesteric liquid crystals, geometric frustration, helicoids, skyrmions

Procedia PDF Downloads 115

Authors: Giulia Leoni, Cristina Florio

Abstract:

The paper aims to investigate the factors driving the increasing alignment of Italian earnings management (EM) research to US research on the same field. After characterizing the progressive similarity of Italian EM research with respect to US one by means of an historical comparison, the paper relies on a subsequent secondary source analysis to detect the possible causes of said alignment. Once identified that the alignment increased along three subsequent periods, the paper analyses and discusses this incremental similarity according to new institutional sociology (NIS) and highlights the presence of different combination of isomorphic pressures that help explaining this incremental similarity. The paper contributes to the institutional literature by providing evidence of isomorphism in academic research; it also contributes to accounting research by indicating the forces that are able to drive change and development in accounting research at national and international level. The paper also enlarges the explanatory value of NIS in alternative contexts, like academic accounting research.

Keywords: accounting research, earnings management, international comparison, Italy, new institutional sociology, US

Procedia PDF Downloads 557

Authors: Margarita Mayoral-Villa, J. Klapp, L. Di G. Sigalotti, J. E. V. Guzmán

Abstract:

Automated learning techniques are widely applied in the energy sector to address challenging problems from a practical point of view. To this end, we discuss the implementation of a Message Passing algorithm (MPNN)within a Graph Neural Network(GNN)to leverage the neighborhood of a set of nodes during the aggregation process. This approach enables the characterization of multiphase diffusion processes in the reservoir, such that the flow paths underlying the interconnections between multiple wells may be inferred from previously available data on flow rates and bottomhole pressures. The results thus obtained compare favorably with the predictions produced by the Reduced Order Capacitance-Resistance Models (CRM) and suggest the potential of MPNNs to enhance the robustness of the forecasts while improving the computational efficiency.

Keywords: multiphase diffusion, message passing neural network, well interconnection, interwell connectivity, graph neural network, capacitance-resistance models

Procedia PDF Downloads 130

Authors: Lee Sunghyoun, Yu Byeongkee, Kim Hyuckjoo, Yun Namkyu, Jung Jongcheon

Abstract:

Most of the recent on-sale oyster mushrooms are raised in a oyster mushroom house, in which the necessary adjustment of growing condition is feasible. The rationale for such artificial growing is the impossibility of successive cultivation in the case of a natural cultivation due to external weather conditions. A oyster mushroom house adopts an equipment called growing bed, laying one growing bed upon another in a multi-column fashion, growing and developing the mushrooms on the respective equipments. The indispensable environment management factors of mushroom cultivation are temperature, humidity, and CO2; on which an appropriate regulation of the three requisites is a necessitated condition for the sake of the total output’s increase. However, due to the multiple layers of growing bed’s disturbance on air circulation, a oyster mushroom house’s internal environmental uniformity meets with considerable instability. This research presents a technology which assures the facilitation of environment regulation over all the internal space of a oyster mushroom house, irrespective of its location. The research staff reinforced the oyster mushroom house’s insulation in order to minimize the external environment’s influence on the oyster mushroom house’s internal environment and installed circulation fan to improve the oyster mushroom house’s interior environmental uniformity. Also, the humidifier nozzle’s position was set to prevent dew condensation when humidifying. As a result, a highly sophisticated management over all the oyster mushroom house‘s internal space was realized with the temperature of 0.2~1.3℃, and the relative humidity of 2~7% at the cultivating stage of mushroom’s growth. Therefore, to maximize oyster mushroom house‘s internal environmental uniformity, it can be concluded that consideration of various factors such as insulation reinforcement, decision on the humidifier nozzle’s location, disposition of circulation fan’s installation and the direction of wind discharge is needed.

Keywords: mushroom growing facility, environmental uniformity, temperature, relative humidity, CO2 concentration

Procedia PDF Downloads 517

Authors: Larry O. Awo, Precious I. Nwachukwu

Abstract:

The increase in proliferation of gambling venues in Nigeria in the last decade has led to an increase in gambling prevalence among the youths who have shown signs of problem gambling and its associated risks and pressures to parents and therapists. The present study sought to investigate the roles of counterfactual thinking (CFT) forms (upward CFT vs downward CFT) in the relationship between impulsivity and gambling intention of 371 Nigerian youths who have gambled prior to the study (mean age = 17.37, SD = 4.13). Hayes PROCESS macro result revealed that, after controlling for age, downward CFT was negatively associated with and contributed to a decrease in gambling intention, while upward CFT was positively associated with and contributed to an increase in gambling intention. Mediation analysis result showed that upward CFT amplified the contribution of impulsivity to gambling intention. The association between impulsivity and gambling was partially weakened by downward CFT, even though this weakness was not significant. We conclude that gambling therapies should encourage packages that attenuate upward CFT impulsivity and at the same time, increase downward CFT skills.

Keywords: upward counterfactuals, downward counterfactuals, gambling intention, nigerian youths

Procedia PDF Downloads 88

Authors: M. I. A. Adziz, J. Sharib Sarip, M. T. Ishak, D. N. A. Tugi

Abstract:

Radiation exposure to humans and the environment is caused by natural radioactive material sources. Given that exposure to people and communities can occur through several pathways, it is necessary to pay attention to the increase in naturally radioactive material, particularly in the soil. Continuous research and monitoring on the distribution and determination of these natural radionuclides' activity as a guide and reference are beneficial, especially in an accidental exposure. Surface soil/sediment samples from several locations identified around the Sembrong catchment area were taken for the study. After 30 days of secular equilibrium with their daughters, the activity concentrations of the naturally occurring radioactive material (NORM) members, i.e. ²²⁶Ra, ²²⁸Ra, ²³⁸U, ²³²Th, and ⁴⁰K, were measured using high purity germanium (HPGe) gamma spectrometer. The results obtained showed that the radioactivity concentration of ²³⁸U ranged between 17.13 - 30.13 Bq/kg, ²³²Th ranged between 22.90 - 40.05 Bq/kg, ²²⁶Ra ranged between 19.19 - 32.10 Bq/kg, ²²⁸Ra ranged between 21.08 - 39.11 Bq/kg and ⁴⁰K ranged between 9.22 - 51.07 Bq/kg with average values of 20.98 Bq/kg, 27.39 Bq/kg, 23.55 Bq/kg, 26.93 Bq/kg and 23.55 Bq/kg respectively. The values obtained from this study were low or equivalent to previously reported in previous studies. It was also found that the mean/mean values obtained for the four parameters of the Radiation Hazard Index, namely radium equivalent activity (Raeq), external dose rate (D), annual effective dose and external hazard index (Hₑₓ), were 65.40 Bq/kg, 29.33 nGy/h, 19.18 ¹⁰⁻⁶Sv and 0.19 respectively. These obtained values are low compared to the world average values and the values of globally applied standards. Comparison with previous studies (dry season) also found that the values for all four parameters were low and equivalent. This indicates the level of radiation hazard in the area around the study is safe for the public.

Keywords: catchment area, gamma spectrometry, naturally occurring radioactive material (NORM), soil

Procedia PDF Downloads 83

Authors: Renu Gautam, S. M. S. Chauhan

Abstract:

The magnetic Fe3O4 nanoparticles has been used as an efficient and facile acid catalyst for the synthesis of calix[4]pyrrole in moderate to excellent yields by the one pot condensation of different ketones and pyrrole. The catalyst was easily recovered using external magnet and reused over several cycles without losing its catalytic activity.

Keywords: calix[4]pyrrole, magnetic, Fe3O4 nanoparticles, catalysis

Procedia PDF Downloads 416

Authors: Sunha Ahn

Abstract:

Intimate relationships have constructed our embodied experiences and emotional memories, which can become grounded as practical knowledge to some extent and play a critical role in social medicine, particularly, in our well-being and mental health. In South Africa, such relational factors are significant for young women and girls in their emotional development period of time, especially, working as the existence of social and relational pressures over feminine sexual health and choices. This, in turn, brings about the absence/lack of communication in intimate relationships, especially with their parents, which leads to a vicious cycle in sexual health behaviour choices. Drawing upon sociological and socio-anthropological understandings of HIV-related issues, this study provides narrative threads of evidence about South African teenage mothers from early-dating debuted to HIV infection. Their stories consist of a visualised figure in chronicle order, illustrating embodied journeys of sexual health choices surrounding uncommunicative relationships and socially-suppressive environments. Methodologically, this qualitative study explored data from mixed online methods: 1) a case study analysing online comments (N = 12,763) on the South African Springster's website, run by the UK-based NGO, namely, Girl Effect; and 2) In-depth online interviews (N = 21) were conducted with young SA women and girls (16-28 ages) recruited in Cape Town, Pretoria, and Johannesburg, SA. Participants consist of both those living with HIV and without. Ethical approval was gained via the College of Social Sciences Ethical Committee at the University of Glasgow, and informed consent was obtained verbally and in writing from participants in due course. Data were thematically applied to an iteratively developed codebook and analysed. There are three kinds of typical pressures as relational factors for them, including peer pressure, partners or boyfriends, and parents’ reactions. Under the patriarchal and religious-devoted social atmospheres, these relationships work as a source of scaredness among young women and girls who could not talk about their sexual health concerns and rights. Such an inability to communicate with intimate relationships, eventually, emerges as a perpetuated or taken-for-granted social environment in South Africa, insistently leading to an increase in unwanted pregnancies or new HIV infections in young South African women and girls. In this sense, this study reveals the pressing need for open communication between generations with accurate information about HIV/AIDS. This also implies that the sociological feminist praxes in South Africa would help eliminate HIV-related stigma as well as construct open space to reduce gender-based violence and sexually-transmitted infection. Ultimately, this will be a road for supporting sexually healthy decisions and well-being across South African generations.

Keywords: HIV, young women, South Africa, intimate relationships, communication, social medicine

Procedia PDF Downloads 46

Authors: E. Shahsavari, R. Ghasemi, A. Akramizadeh

Abstract:

This paper presents a new method to design nonlinear feedback linearization controller for polymer electrolyte membrane fuel cells (PEMFCs). A nonlinear controller is designed based on nonlinear model to prolong the stack life of PEM fuel cells. Since it is known that large deviations between hydrogen and oxygen partial pressures can cause severe membrane damage in the fuel cell, feedback linearization is applied to the PEM fuel cell system so that the deviation can be kept as small as possible during disturbances or load variations. To obtain an accurate feedback linearization controller, tuning the linear parameters are always important. So in proposed study NSGA_II method was used to tune the designed controller in aim to decrease the controller tracking error. The simulation result showed that the proposed method tuned the controller efficiently.

Keywords: nonlinear dynamic model, polymer electrolyte membrane fuel cells, feedback linearization, optimal control, NSGA_II

Procedia PDF Downloads 501

Authors: Soheila Sadeghi

Abstract:

In construction projects, predicting project performance metrics accurately is essential for effective management and successful delivery. However, conventional methods often depend on fixed baseline plans, disregarding the evolving nature of project progress and external influences. To address this issue, we introduce a distinct approach based on machine learning to forecast key performance indicators, such as cost variance and earned value, for each Work Breakdown Structure (WBS) category within an urban road reconstruction project. Our proposed model leverages time series forecasting techniques, namely Autoregressive Integrated Moving Average (ARIMA) and Long Short-Term Memory (LSTM) networks, to predict future performance by analyzing historical data and project progress. Additionally, the model incorporates external factors, including weather patterns and resource availability, as features to improve forecast accuracy. By harnessing the predictive capabilities of machine learning, our performance forecasting model enables project managers to proactively identify potential deviations from the baseline plan and take timely corrective measures. To validate the effectiveness of the proposed approach, we conduct a case study on an urban road reconstruction project, comparing the model's predictions with actual project performance data. The outcomes of this research contribute to the advancement of project management practices in the construction industry by providing a data-driven solution for enhancing project performance monitoring and control.

Keywords: project performance forecasting, machine learning, time series forecasting, cost variance, schedule variance, earned value management

Procedia PDF Downloads 18

Authors: Sedigheh Abbasnasab Sardareh

Abstract:

The current study investigates ESL teachers' voices in order to formulate further research on the effectiveness of the SBOA practices. It is an attempt to find out (1) what are ESL experienced teachers’ perceptions, experiences, attitudes, and beliefs of SBOA; (2) what teaching and learning aspects of SBOA needs focus to enhance its effectiveness; (3) external issues related to the implementation of SBOA; (4) internal issues related to the implementation of SBOA; and also (5) perceived recommendations on SBOA. The study utilized focus group discussion sessions. 9 experienced ESL (5 females and 4 males) teachers were selected based on the consent letters sent to them. These teachers had over 20 years experience in both traditional and SBOA-type assessment and the train-the-trainer experts recommended by the Ministry of Education. Respondents were guided with open-ended questions to extracts their perceived experiences implementing SBOA guided structurally by the author as the moderator. Data were first discussed with the respondents for further clarifications and then only analyzed and re-confirmed with some recommendations before the final presentation of this preliminary results were presented here. The focus group discussions yielded some important perceived views on the SBOA implementation. Some of the themes were discussed and some recommendations were proposed for further in-depth study by the Ministry of Education. Some of the future directions based on the results were also put forward. Some external and internal variables were important in order for successful implementation of SBOA. Mere implementing a policy should be taken into consideration because this might impede some of the teaching and learning processes both by the classroom stakeholders such as teachers and student. More research methods such as the use of questionnaires could be utilized to further investigate to large populations of teacher educators in Malaysia.

Keywords: school based oral assessment, Malaysia, ESL, focus group discussion

Procedia PDF Downloads 314

Authors: N. Naz, A. D. Domenico, M. N. Huda

Abstract:

Soft Robotics is a rapidly growing multidisciplinary field where robots are fabricated using highly deformable materials motivated by bioinspired designs. The high dexterity and adaptability to the external environments during contact make soft robots ideal for applications such as gripping delicate objects, locomotion, and biomedical devices. The actuation system of soft robots mainly includes fluidic, tendon-driven, and smart material actuation. Among them, Soft Pneumatic Actuator, also known as SPA, remains the most popular choice due to its flexibility, safety, easy implementation, and cost-effectiveness. However, at present, most of the fabrication of SPA is still based on traditional molding and casting techniques where the mold is 3d printed into which silicone rubber is cast and consolidated. This conventional method is time-consuming and involves intensive manual labour with the limitation of repeatability and accuracy in design. Recent advancements in direct 3d printing of different soft materials can significantly reduce the repetitive manual task with an ability to fabricate complex geometries and multicomponent designs in a single manufacturing step. The aim of this research work is to design and analyse the Soft Pneumatic Actuator (SPA) utilizing both conventional casting and modern direct 3d printing technologies. The mold of the SPA for traditional casting is 3d printed using fused deposition modeling (FDM) with the polylactic acid (PLA) thermoplastic wire. Hyperelastic soft materials such as Ecoflex-0030/0050 are cast into the mold and consolidated using a lab oven. The bending behaviour is observed experimentally with different pressures of air compressor to ensure uniform bending without any failure. For direct 3D-printing of SPA fused deposition modeling (FDM) with thermoplastic polyurethane (TPU) and stereolithography (SLA) with an elastic resin are used. The actuator is modeled using the finite element method (FEM) to analyse the nonlinear bending behaviour, stress concentration and strain distribution of different hyperelastic materials after pressurization. FEM analysis is carried out using Ansys Workbench software with a Yeon-2nd order hyperelastic material model. FEM includes long-shape deformation, contact between surfaces, and gravity influences. For mesh generation, quadratic tetrahedron, hybrid, and constant pressure mesh are used. SPA is connected to a baseplate that is in connection with the air compressor. A fixed boundary is applied on the baseplate, and static pressure is applied orthogonally to all surfaces of the internal chambers and channels with a closed continuum model. The simulated results from FEM are compared with the experimental results. The experiments are performed in a laboratory set-up where the developed SPA is connected to a compressed air source with a pressure gauge. A comparison study based on performance analysis is done between FDM and SLA printed SPA with the molded counterparts. Furthermore, the molded and 3d printed SPA has been used to develop a three-finger soft pneumatic gripper and has been tested for handling delicate objects.

Keywords: finite element method, fused deposition modeling, hyperelastic, soft pneumatic actuator

Procedia PDF Downloads 77