Search results for: survival rates

Authors: Khairani Binti Supyan, Fatimah Khalid, Mas Rina Mustaffa, Azreen Bin Azman, Amirul Azuani Romle

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Perennial plant classification plays a significant role in various agricultural and environmental applications, assisting in plant identification, disease detection, and biodiversity monitoring. Nevertheless, attaining high accuracy in perennial plant image classification remains challenging due to the complex variations in plant appearance, the diverse range of environmental conditions under which images are captured, and the inherent variability in image quality stemming from various factors such as lighting conditions, camera settings, and focus. This paper proposes an adaptation approach to optimize perennial plant image classification by fine-tuning the pre-trained DNNs model. This paper explores the efficacy of fine-tuning prevalent architectures, namely VGG16, ResNet50, and InceptionV3, leveraging transfer learning to tailor the models to the specific characteristics of perennial plant datasets. A subset of the MYLPHerbs dataset consisted of 6 perennial plant species of 13481 images under various environmental conditions that were used in the experiments. Different strategies for fine-tuning, including adjusting learning rates, training set sizes, data augmentation, and architectural modifications, were investigated. The experimental outcomes underscore the effectiveness of fine-tuning deep neural networks for perennial plant image classification, with ResNet50 showcasing the highest accuracy of 99.78%. Despite ResNet50's superior performance, both VGG16 and InceptionV3 achieved commendable accuracy of 99.67% and 99.37%, respectively. The overall outcomes reaffirm the robustness of the fine-tuning approach across different deep neural network architectures, offering insights into strategies for optimizing model performance in the domain of perennial plant image classification.

Keywords: perennial plants, image classification, deep neural networks, fine-tuning, transfer learning, VGG16, ResNet50, InceptionV3

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Authors: A. Alzeyadi, E. Loffill, R. Alkhaddar

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Continuous upflow filters can combine the nutrient (nitrogen and phosphate) and suspended solid removal in one unit process. The contaminant removal could be achieved chemically or biologically; in both processes the filter removal efficiency depends on the interaction between the packed filter media and the influent. In this paper a residence time distribution (RTD) study was carried out to understand and compare the transfer behaviour of contaminants through a selected filter media packed in a laboratory-scale continuous up flow filter; the selected filter media are limestone and white dolomite. The experimental work was conducted by injecting a tracer (red drain dye tracer –RDD) into the filtration system and then measuring the tracer concentration at the outflow as a function of time; the tracer injection was applied at hydraulic loading rates (HLRs) (3.8 to 15.2 m h-1). The results were analysed according to the cumulative distribution function F(t) to estimate the residence time of the tracer molecules inside the filter media. The mean residence time (MRT) and variance σ2 are two moments of RTD that were calculated to compare the RTD characteristics of limestone with white dolomite. The results showed that the exit-age distribution of the tracer looks better at HLRs (3.8 to 7.6 m h-1) and (3.8 m h-1) for limestone and white dolomite respectively. At these HLRs the cumulative distribution function F(t) revealed that the residence time of the tracer inside the limestone was longer than in the white dolomite; whereas all the tracer took 8 minutes to leave the white dolomite at 3.8 m h-1. On the other hand, the same amount of the tracer took 10 minutes to leave the limestone at the same HLR. In conclusion, the determination of the optimal level of hydraulic loading rate, which achieved the better influent distribution over the filtration system, helps to identify the applicability of the material as filter media. Further work will be applied to examine the efficiency of the limestone and white dolomite for phosphate removal by pumping a phosphate solution into the filter at HLRs (3.8 to 7.6 m h-1).

Keywords: filter media, hydraulic loading rate, residence time distribution, tracer

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Authors: Matej Buzgo, Erico Himawan, Ksenija JašIna, Aiva Simaite

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Electrospinning is a versatile and efficient technology for producing nanofibers for biomedical applications. One of the most common polymers used for the preparation of nanofibers for regenerative medicine and drug delivery applications is polycaprolactone (PCL). PCL is a biocompatible and bioabsorbable material that can be used to stimulate the regeneration of various tissues. It is also a common material used for the development of drug delivery systems by blending the polymer with small active molecules. However, for many drug delivery applications, e.g. cancer immunotherapy, PCL biodegradation rate that may exceed 9 months is too long, and faster nanofiber dissolution is needed. In this paper, we investigate the dissolution and small molecule release rates of PCL blends with two hydrophilic polymers: polyethylene oxide (PEO) or polyvinylpyrrolidone (PVP). We show that adding hydrophilic polymer to the PCL reduces the water contact angle, increases the dissolution rate, and strengthens the interactions between the hydrophilic drug and polymer matrix that further sustain its release. Finally using this method, we were also able to increase the nanofiber degradation rate when PCL-PEO and PCL-PVP were used as a shell in the electrospun core-shell nanofibers and spread up the release of active proteins from their core. Electrospinning can be used for the preparation of the core-shell nanofibers, where active ingredients are encapsulated in the core and their release rate is regulated by the shell. However, such fibers are usually prepared by coaxial electrospinning that is an extremely low-throughput technique. An alternative is emulsion electrospinning that could be upscaled using needleless blades. In this work, we investigate the possibility of using emulsion electrospinning for encapsulation and sustained release of the growth factors for the development of the organotypic skin models. The core-shell nanofibers were prepared using the optimized formulation and the release rate of proteins from the fibers was investigated for 2 weeks – typical cell culture conditions.

Keywords: electrospinning, polycaprolactone (PCL), polyethylene oxide (PEO), polyvinylpyrrolidone (PVP)

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Authors: Lina Paola Orozco Marin, Yuliet Montoya Osorio, John Bustamante Osorno

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Ischemic events can culminate in acute myocardial infarction by irreversible cardiac lesions that cannot be restored due to the limited regenerative capacity of the heart. Cell therapy seeks to replace these injured or necrotic cells by transplanting healthy and functional cells. The therapeutic alternatives proposed by tissue engineering and cardiovascular regenerative medicine are the use of biomaterials to mimic the native extracellular medium, which is full of proteins, proteoglycans, and glycoproteins. The selected biomaterials must provide structural support to the encapsulated cells to avoid their migration and death in the host tissue. In this context, the present research work focused on developing a natural thermosensitive hydrogel, its physical and chemical characterization, and the determination of its biocompatibility in vitro. The hydrogel was developed by mixing hydrolyzed bovine and porcine collagen at 2% w/v, chitosan at 2.5% w/v, and beta-glycerolphosphate at 8.5% w/w and 10.5% w/w in magnetic stirring at 4°C. Once obtained, the thermosensitivity and gelation time were determined, incubating the samples at 37°C and evaluating them through the inverted tube method. The morphological characterization of the hydrogels was carried out through scanning electron microscopy. Chemical characterization was carried out employing infrared spectroscopy. The biocompatibility was determined using the MTT cytotoxicity test according to the ISO 10993-5 standard for the hydrogel’s precursors using the fetal human ventricular cardiomyocytes cell line RL-14. The RL-14 cells were also seeded on the top of the hydrogels, and the supernatants were subculture at different periods to their observation under a bright field microscope. Four types of thermosensitive hydrogels were obtained, which differ in their composition and concentration, called A1 (chitosan/bovine collagen/beta-glycerolphosphate 8.5%w/w), A2 (chitosan/porcine collagen/beta-glycerolphosphate 8.5%), B1 (chitosan/bovine collagen/beta-glycerolphosphate 10.5%) and B2 (chitosan/porcine collagen/beta-glycerolphosphate 10.5%). A1 and A2 had a gelation time of 40 minutes, and B1 and B2 had a gelation time of 30 minutes at 37°C. Electron micrographs revealed a three-dimensional internal structure with interconnected pores for the four types of hydrogels. This facilitates the exchange of nutrients, oxygen, and the exit of metabolites, allowing to preserve a microenvironment suitable for cell proliferation. In the infrared spectra, it was possible to observe the interaction that occurs between the amides of polymeric compounds with the phosphate groups of beta-glycerolphosphate. Finally, the biocompatibility tests indicated that cells in contact with the hydrogel or with each of its precursors are not affected in their proliferation capacity for a period of 16 days. These results show the potential of the hydrogel to increase the cell survival rate in the cardiac cell therapies under investigation. Moreover, the results lay the foundations for its characterization and biological evaluation in both in vitro and in vivo models.

Keywords: cardiac cell therapy, cardiac ischemia, natural polymers, thermosensitive hydrogel

Procedia PDF Downloads 177

Authors: Smruti Mahapatra, Dipankar Biswas, Richard Um, Michael Meggyesy, Riccardo Serra, Noah Gorelick, Steven Marra, Amir Manbachi, Mark G. Luciano

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Intracranial pressure (ICP) is profoundly regulated by the effects of cardiac pulsation and the volume of the incoming blood. Furthermore, these effects on ICP are incremented by the presence of a rigid skull that does not allow for changes in total volume during the cardiac cycle. These factors play a pivotal role in cerebrospinal fluid (CSF) dynamics and distribution, with consequences that are not well understood to this date and that may have a deep effect on the Central Nervous System (CNS) functioning. We designed this study with two specific aims: (a) To study how pulsatility influences local CSF flow, and (b) To study how modulating intracranial pressure affects drug distribution throughout the SAS globally. In order to achieve these aims, we built an elaborate in-vitro model of the SAS closely mimicking the dimensions and flow rates of physiological systems. To modulate intracranial pressure, we used an intracranially implanted, cardiac-gated, volume-oscillating balloon (CADENCE device). Commercially available dye was used to visualize changes in CSF flow. We first implemented two control cases, seeing how the tracer behaves in the presence of pulsations from the brain phantom and the balloon individually. After establishing the controls, we tested 2 cases, having the brain and the balloon pulsate together in sync and out of sync. We then analyzed the distribution area using image processing software. The in-sync case produced a significant increase, 5x times, in the tracer distribution area relative to the out-of-sync case. Assuming that the tracer fluid would mimic blood flow movement, a drug introduced in the SAS with such a system in place would enhance drug distribution and increase the bioavailability of therapeutic drugs to a wider spectrum of brain tissue.

Keywords: blood-brain barrier, cardiac-gated, cerebrospinal fluid, drug delivery, neurosurgery

Procedia PDF Downloads 175

Authors: Ming-Juei Chang, Hui-Ing Ma, Tsung-Hsueh Lu

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Introduction: Because of the advance of medical care (e.g., ventilation techniques and gastrostomy feeding), more and more children with CP can live to adulthood. However, little is known about the use of health care services from children to adults who have CP. The patterns of utilization of ambulatory care are heavily influenced by insurance coverage and primary care gatekeeper regulation. The purpose of this study was to examine patterns of ambulatory care utilization among individuals with CP in Taiwan, a country with universal coverage and no gatekeeper regulation. Methods: A representative sample of one million patients (about 1/23 of total population) covered by Taiwan’s National Health Insurance was used to analyze the ambulatory care utilization in individuals with CP. Data were analyzed by 3 different age groups (children, youth and adults) during 2000 to 2003. Participants were identified by the presence of CP diagnosis made by pediatricians or physicians of physical and rehabilitation medicine and stated at least three times in claims data. Results: Annual rates of outpatient physician visits were 31680 for children, 16492 for youth, and 28617 for adults with CP (per 1000 persons). Individuals with CP received over 50% of their outpatient care from hospital outpatient department. Higher use of specialist physician services was found in children (54.7%) than in the other two age groups (28.4% in youth and 18.8% in adults). Diseases of respiratory system were the most frequent diagnoses for visits in both children and youth with CP. Diseases of the circulatory system were the main reasons (24.3%) that adults with CP visited hospital outpatient care department or clinics. Conclusion: This study showed different patterns of ambulatory care utilization among different age groups. It appears that youth and adults with CP continue to have complex health issues and rely heavily on the health care system. Additional studies are needed to determine the factors which influence ambulatory care utilization among individuals with CP.

Keywords: cerebral palsy, health services, lifespan, universal coverage

Procedia PDF Downloads 372

Authors: Justin P. Pool, Haruyo Yoshida

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This research focuses on the effects of creating an English as a foreign language curriculum that combines online learning and classroom teaching in a complementary manner. Through pre- and post-test results, teacher observation, and learner reflection, it will be shown that learners can benefit from online programs focusing on receptive skills if combined with a communicative classroom environment that encourages learners to develop their productive skills. Much research has lamented the fact that many modern mobile assisted language learning apps do not take advantage of the affordances of modern technology by focusing only on receptive skills rather than inviting learners to interact with one another and develop communities of practice. This research takes into account the realities of the state of such apps and focuses on how to best create a curriculum that complements apps which focus on receptive skills. The research involved 15 adult learners working for a business in Japan simultaneously engaging in 1) a commercial online English language learning application that focused on reading, listening, grammar, and vocabulary and 2) a 15-week class focused on communicative language teaching, presentation skills, and mitigation of error aversion tendencies. Participants of the study experienced large gains on a standardized test, increased motivation and willingness to communicate, and asserted that they felt more confident regarding English communication. Moreover, learners continued to study independently at higher rates after the study than they had before the onset of the program. This paper will include the details of the program, reveal the improvement in test scores, share learner reflections, and critically view current evaluation models for mobile assisted language learning applications.

Keywords: adult learners, communicative language teaching, mobile assisted language learning, motivation

Procedia PDF Downloads 127

Authors: Leonard Chimaobi Agim, Charles Arinzechukwu Igwe, Emmanuel Uzoma Onweremadu, Gabreil Osuji

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Soil erosion has been linked to stream sedimentation, ecosystem degradation, and loss of soil nutrients. A study was conducted to evaluate the effect of some organic amendment on sediment yield, splash loss, and runoff of soils of selected parent materials in southeastern Nigeria. A total of 20 locations, five from each of four parent materials namely: Asu River Group (ARG), Bende Ameki Group (BAG), Coastal Plain Sand (CPS) and Falsebedded Sandstone (FBS) were used for the study. Collected soil samples were analyzed with standard methods for the initial soil properties. Rainfall simulation at an intensity of 190 mm hr-1was conducted for 30 minutes on the soil samples at both the initial stage and after amendment to obtain erosion parameters. The influence of parent material on sediment yield, splash loss and runoff based on rainfall simulation was tested for using one way analyses of variance, while the influence of organic material and their combinations were a factorially fitted in a randomized complete block design. The organic amendments include; goat dropping (GD), poultry dropping (PD), municipal solid waste (MSW) and their combinations (COA) applied at four rates of 0, 10, 20 and 30 t ha-1 respectively. Data were analyzed using analyses of variance suitable for a factorial experiment. Significant means were separated using LSD at 5 % probability levels. Result showed significant (p ≤ 0.05) lower values of sediment yield, splash loss and runoff following amendment. For instance, organic amendment reduced sediment yield under wet and dry runs by 12.91 % and 26.16% in Ishiagu, 40.76% and 45.67%, in Bende, 16.17% and 50% in Obinze and 22.80% and 42.35% in Umulolo respectively. Goat dropping and combination of amendment gave the best results in reducing sediment yield.

Keywords: organic amendment, parent material, rainfall simulation, soil erosion

Procedia PDF Downloads 336

Authors: Eftychia Pappa, Heleni Vastardis, Christos Rahiotis, Andriani Vazaiou

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The aim of this study was to evaluate the prevalence of dry-mouth symptoms (xerostomia) and compare it with alterations in salivary characteristics of children and adolescents with type 1 diabetes (DM1), as measured with the use of chair-side saliva tests. This study also investigated the possible association between salivary dysfunction and incidence of caries, in relation to the level of metabolic control. A cross-sectional study was performed on young patients (6-18 years old) allocated among 3 groups: 40 patients poorly-controlled (DM1-A, HbA1c>8%), 40 well-controlled (DM1-B, HbA1c≤8%) and 40 age- and sex-matched healthy controls. The study was approved by the Research Ethics Committee of University of Athens and the parents signed written informed consent. All subjects were examined for dental caries, oral hygiene and salivary factors. Assessments of salivary function included self-reported xerostomia, quantification of resting and stimulated whole saliva flow rates, pH values, buffering capacity and saliva’s viscosity. Salivary characteristics were evaluated with the use of GC Saliva Check Buffer (3Μ ESPE). Data were analysed by chi-square and Kruskal-Wallis tests. Subjects with diabetes reported xerostomia more frequently than healthy controls (p<0.05). Unstimulated salivary flow rate and pH values remained significantly lower in DM1-A compared to DM1-B and controls. Low values of resting salivary flow rate were associated with a higher prevalence of dental caries in children and adolescents with poorly-controlled DM1 (p<0.05). The results suggested that diabetes-induced alterations in salivary characteristics are indicative of higher caries susceptibility of diabetics and chair-side saliva tests are a useful tool for the evaluation of caries risk assessment.

Keywords: caries risk assessment, saliva diagnostic tests, type 1 diabetes, xerostomia

Procedia PDF Downloads 277

Authors: Mohd Ali Abbas Zaidi, Meenu Sachdeva, Jonaki Sen

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In the vertebrate embryo, the forebrain anlagen develops from the anterior-most region of the neural tube which is the precursor of the central nervous system (CNS). The roof plate located at the dorsal midline region of the forebrain anlagen, acts as a source of several secreted molecules involved in patterning and morphogenesis of the forebrain. One such key morphogenetic event is the invagination of the forebrain roof plate which results in separation of the single forebrain vesicle into two cerebral hemispheres. Retinoic acid (RA) signaling plays a key role in this process. Blocking RA signaling at the dorsal forebrain midline inhibits dorsal invagination and results in the absence of certain key features of this region, such as thinning of the neuroepithelium and a lowering of cell proliferation. At present we are investigating the possibility of other signaling pathways acting in concert with RA signaling to regulate this process. We have focused on BMP signaling, which we found to be active in a mutually exclusive domain to that of RA signaling within the roof plate. We have also observed that there is a change in BMP signaling activity on modulation of RA signaling indicating an antagonistic relationship between the two. Moreover, constitutive activation of BMP signaling seems to completely inhibit thinning and partially affect invagination, leaving the lowering of cell proliferation in the midline unaffected. We are employing in-silico modeling as well as molecular manipulations to investigate the relative contribution if any, of regional differences in rates of cell proliferation and thinning of the neuroepithelium towards the process of invagination. We have found expression of certain cell adhesion molecules in forebrain roof-plate whose mRNA localization across the thickness of neuroepithelium is influenced by Bmp and RA signaling, giving regional rigidity to roof plate and assisting invagination. We also found expression of certain cytoskeleton modifiers in a localized small domains in invaginating forebrain roof plate suggesting that midline invagination is under control of many factors.

Keywords: bone morphogenetic signaling, cytoskeleton, cell adhesion molecules, forebrain roof plate, retinoic acid signaling

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Authors: Muhammed Ordu, Eren Demir, Chris Tofallis

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The number of inpatient admissions in the UK has been significantly increasing over the past decade. These increases cause bed occupancy rates to exceed the target level (85%) set by the Department of Health in England. Therefore, hospital service managers are struggling to better manage key resource such as beds. On the other hand, this severe demand pressure might lead to confusion in wards. For example, patients can be admitted to the ward of another inpatient specialty due to lack of resources (i.e., bed). This study aims to develop a simulation-optimization model to reallocate the available number of beds in a mid-sized hospital in the UK. A hospital simulation model was developed to capture the stochastic behaviours of the hospital by taking into account the accident and emergency department, all outpatient and inpatient services, and the interactions between each other. A couple of outputs of the simulation model (e.g., average length of stay and revenue) were generated as inputs to be used in the optimization model. An integer linear programming was developed under a number of constraints (financial, demand, target level of bed occupancy rate and staffing level) with the aims of maximizing number of admitted patients. In addition, a sensitivity analysis was carried out by taking into account unexpected increases on inpatient demand over the next 12 months. As a result, the major findings of the approach proposed in this study optimally reallocate the available number of beds for each inpatient speciality and reveal that 74 beds are idle. In addition, the findings of the study indicate that the hospital wards will be able to cope with 14% demand increase at most in the projected year. In conclusion, this paper sheds a new light on how best to reallocate beds in order to cope with current and future demand for healthcare services.

Keywords: bed occupancy rate, bed reallocation, discrete event simulation, inpatient admissions, integer linear programming, projected usage

Procedia PDF Downloads 133

Authors: Alejandro Arnaldo Barroso Martinez

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Unlike sex, which is constituted by anatomic-physiological differences, gender is a social construction. Our thoughts and behaviors as females and males are not etched in stone by our biology but rather from how society expects us to think and behave based on our sex assignment in the womb. Social expectations, values, and roles are taken on by individuals and shape the ways considered acceptable and linked to our bodies, feelings, and interpersonal relationships. Furthermore, these evolve into dire consequences for those who do not meet these disciplinary, economic, and cultural standards. Then, the social learning of gender identity implies the individual’s psychological sense of being, and it might be highly linked to a sense of life and suicide attempts. As a result, suicide has been considered a gender issue with differences in the rates and means used by men and women worldwide. Nevertheless, there has been a misunderstanding of the meaning of being male or female in a particular context and how it becomes a risk process for suicide attempts. For this reason, the general objective of the current research is to explain how this process occurs in Cuba. From a Critical Sociology and Social Psychology, a qualitative methodology was developed through six case studies and qualitative in-depth interviews. The analysis is focused on the sequence and interplay between two dimensions of meaning: signifiers and voices. Findings show that the risk process of suicide attempts in Cuba means some patriarchal beliefs and practices as part of informal educational models and some positivist practices in mental health attention. Findings also show that community relations create a sense of belonging, and it is a protection against suicide attempts in Cuba. Those frames of signifiers and voices explain in both males and females but differently when and how they are suffering from isolation, violence, the normalization of emotional awareness, and emotional distress expression. Suicide prevention programs should take gender learning into account as a cultural process.

Keywords: social constructions, gender identity, meanings, suicide attempt

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Authors: Preethy Mary Donald, Renjith George

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Oral tori are localized non-neoplastic protuberances of maxilla and mandible. Torus palatinus (TP) is found on the midline of the roof of mouth existing as single growth or in clusters. Torus mandibularis(TM) is located on the lingual aspect of the mandible commonly between canine and premolar region. Etiology of their presence was not clear and was found to be multifactorial. Their variations in relation to age, gender, ethnicity and also the characteristics of TP and TM have become the interest of multiple studies. The objectives of this study were to determine the prevalence of torus palatinus (TP) and torus mandibularis (TM) among patients who have visited outpatient department, Faculty of Dentistry, Melaka Manipal Medical College. 108 patients were examined for the presence of oral tori at the outpatient department, Faculty of Dentistry, Melaka-Manipal Medical College. Factors such as age, gender, ethnicity of the patients and size, shape, location of the oral tori were studied. For TP, Malays (62.96%) have been found to have the highest prevalence than Chinese (43.3%) and Indians (35.71%). For TM, Chinese (7.46%) had predominated compared to Malays (7.41%) and Indians (0%). There is no significant association between occurrence of TP and TM with age, gender and ethnicity. For Torus palatinus, the most common size was Grade 1(1-3mm), most common location was molar region, and the most common shape was spindle. For Torus mandibularis, the most frequent location was canine premolar region and exists in unilateral single or bilateral single fashion. The overall prevalence rates were 47.2% for TP and 6.48% for TM. However, there is no significant association between occurrence of TP and TM with age, gender and ethnicity. The results showed variations in clinical characteristics and support the findings that occurrence of tori is a dynamic phenomenon which is multifactorial owing to the environmental factors such as stress from occlusion and dietary habits. It could be due to the genetic make-up of the individual.

Keywords: torus palatinus, torus mandibularis, age, gender

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Authors: D. M. Koers, A. J. Groen, P. D. Englis, R. Harms

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We are witnessing the largest level of displacement of people since World War II. Refugees want to become independent as quickly as possible and build a new, safe future; however, access to the labor market is difficult and they face many problems that are not easily solved. This makes self-employment including social entrepreneurship a valuable alternative. Our research studied refugee-based entrepreneurship and examined whether prior knowledge, unmet personal needs and contextual factors influence how refugees recognize opportunities and if this influences their social orientation. In addition, we examine the barriers refugees face when starting up a company in the Netherlands. We use a case study design with a mixed-method approach, combining in-depth interviews and survey data. Data was collected from two Dutch entrepreneurial training programs in the Netherlands. We have a sample size of 27 latent refugee entrepreneurs. Our results show that refugees score high on the social entrepreneurial measures. They perceive themselves as having a strong social vision and are determined to defend a social need. They also score high on sustainability and state that their business ideas improve the quality of life on the long run. Based on these findings, we did not expect that only 5 participants had business ideas with a social orientation. In this group, 37,5% started a company before and 77.8% used their personal experience to come up with this business idea. Another 70,3% had the higher professional education or academic education. In the interviews, we found that they often copy and paste their gained experience from a previous profession on their new context and expect that it would work well. The social aspect lies in their cultural values and personal beliefs but is not reflected in their business models. One of the reasons could be that the context in which the refugee operates as a moderator suppressing the social mission and social value creation opportunities. Refugees are first and foremost focused on their survival. They do not want to be on social welfare and feel a strong need to be independent. Since they cannot access the labor market easily and face labor market discrimination they want to start a company. Another factor that explains lack of the social orientation in their business ideas is that social entrepreneurship is not a known concept in their home countries. Their idea of entrepreneurship differs substantially. We found that a huge barrier for refugees is their expectations about setting up a business, which are often not realistic because they have little knowledge about the system, institutions and corresponding red tape. In those instances, can the institutional configuration of a country, cultural differences, and perspective on entrepreneurship hinders social entrepreneurship. In conclusion, there might be latent potential for social entrepreneurship in refugees but there are many barriers to overcome. Overcoming these barriers can enhance local communities and enhance integration. In addition it has a positive financial impact on the host country because it reduces the pressure on the social system and stimulate the economy.

Keywords: immigrant entrepreneurship, refugee entrepreneurship, social entrepreneurship, prior experience, opportunity recognition

Procedia PDF Downloads 158

Authors: Shoumodip Roy, Ankit Singhania, K. R. K. Rao, Ravi Shankar, M. K. Agarwal, R. V. Ramna, Uttam Singh

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The productivity of a blast furnace and the quality of the hot metal produced are significantly dependent on the smoothness and stability of furnace operation. The permeability of the furnace bed, as well as the gas flow pattern, influences the steady control of process parameters. The softening – melting zone that is formed inside the furnace contributes largely in distribution of the gas flow and the bed permeability. A better shape of softening-melting zone enhances the performance of blast furnace, thereby reducing the fuel rates and improving furnace life. Therefore, predictive model of the softening- melting zone profile can be utilized to control and improve the furnace operation. The shape of softening-melting zone depends upon the physical and chemical properties of the agglomerates and iron ore charged in the furnace. The variations in the agglomerate proportion in the burden at G Blast furnace disturbed the furnace stability. During such circumstances, it was analyzed that a w-shape softening-melting zone profile was formed inside the furnace. The formation of w-shape zone resulted in poor bed permeability and non-uniform gas flow. There was a significant increase in the heat loss at the lower zone of the furnace. The fuel demand increased, and the huge production loss was incurred. Therefore, visibility of softening-melting zone profile was necessary in order to pro-actively optimize the process parameters and thereby to operate the furnace smoothly. Using stave temperatures, a model was developed that predicted the shape of the softening-melting zone inside the furnace. It was observed that furnace operated smoothly during inverse V-shape of the zone and vice-versa during w-shape. This model helped to control the heat loss, optimize the burden distribution and lower the fuel rate at G Blast Furnace, TSL Jamshedpur. As a result of furnace stabilization productivity increased by 10% and fuel rate reduced by 80 kg/thm. Details of the process have been discussed in this paper.

Keywords: agglomerate, blast furnace, permeability, softening-melting

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Authors: Maiya Smith, Tyler Thorne

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Background: The Pacific faces multiple healthcare crises, including high rates of noncommunicable diseases, infectious disease outbreaks, and susceptibility to natural disasters. These issues are expected to worsen in the coming decades, increasing the burden on an already understaffed healthcare system. Telehealth is not new to the Pacific, but improvements in technology and accessibility have increased its utility and have already proven to reduce costs and increase access to care in remote areas. Telehealth includes distance learning; a form of education that can help alleviate many healthcare issues by providing continuing education to healthcare professionals and upskilling staff, while decreasing costs. This study examined distance learning programs at the Ministry of Health in the Pacific nation of Palau and identified key elements to their successful distance learning programs. Methods: Staff at the Belau National Hospital in Koror, Palau as well as private practitioners were interviewed to assess distance learning programs utilized. This included physicians, IT personnel, public health members, and department managers of allied health. In total, 36 people were interviewed. Standardized questions and surveys were conducted in person throughout the month of July 2019. Results: Two examples of successful distance learning programs were identified. Looking at the factors that made these programs successful, as well as consulting with staff who undertook other distance learning programs, four factors for success were determined: having a cohort, having a facilitator, dedicated study time off from work, and motivation. Discussion: In countries as geographically isolated as the Pacific, with poor access to specialists and resources, telehealth has the potential to radically change how healthcare is delivered. Palau shares similar resources and issues as other countries in the Pacific and the lessons learned from their successful programs can be adapted to help other Pacific nations develop their own distance learning programs.

Keywords: distance learning, Pacific, Palau, telehealth

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Authors: Himanshu Shekhar Maharana, S. K .Dash

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Economic Load Dispatch (ELD) proves to be a vital optimization process in electric power system for allocating generation amongst various units to compute the cost of generation, the cost of emission involving global warming gases like sulphur dioxide, nitrous oxide and carbon monoxide etc. In this dissertation, we emphasize ramp rate constriction factor based particle swarm optimization (RRCPSO) for analyzing various performance objectives, namely cost of generation, cost of emission, and a dual objective function involving both these objectives through the experimental simulated results. A 6-unit 30 bus IEEE test case system has been utilized for simulating the results involving improved weight factor advanced ramp rate limit constraints for optimizing total cost of generation and emission. This method increases the tendency of particles to venture into the solution space to ameliorate their convergence rates. Earlier works through dispersed PSO (DPSO) and constriction factor based PSO (CPSO) give rise to comparatively higher computational time and less good optimal solution at par with current dissertation. This paper deals with ramp rate and constriction factor based well defined ramp rate PSO to compute various objectives namely cost, emission and total objective etc. and compares the result with DPSO and weight improved PSO (WIPSO) techniques illustrating lesser computational time and better optimal solution. 

Keywords: economic load dispatch (ELD), constriction factor based particle swarm optimization (CPSO), dispersed particle swarm optimization (DPSO), weight improved particle swarm optimization (WIPSO), ramp rate and constriction factor based particle swarm optimization (RRCPSO)

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Authors: Osama Ahmed Ibrahim Masoud, Mohamed Ibrahim Mohamed Abdelhadi, Ahmed Mohamed Seddik Hassan

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The problem of study focuses on thermal comfort realization in a residential building during hot and dry climate periods consumes a major electrical energy for air conditioning operation. Thermal comfort realization in a residential building during such climate becomes more difficult regarding the phenomena of climate change, and the use of building and construction materials which have the feature of heat conduction as (bricks-reinforced concrete) and the global energy crises. For that, this study aims to how to realize internal thermal comfort through how to make the best use of building services (temporarily used service spaces) for reducing the electrical energy transfer and saving self-shading. In addition, the possibility of reduction traditional energy (fossil fuel) consumed in cooling through the use of building services for reducing the internal thermal comfort and the relationship between them. This study is based on measuring the consumed electrical energy rate in cooling (by using Design-Builder program) for a residential building (the place of study is: Egypt- Suez Canal- Suez City), this design model has lots of alternatives designs for the place of building services (center of building- the eastern front- southeastern front- the southern front- the south-west front, the western front). The building services are placed on the fronts with different rates for determining the best rate on fronts which realizes thermal comfort with the lowest of energy consumption used in cooling. Findings of the study indicate to that the best position for building services is on the west front then the south-west front, and the more the building services increase, the more energy consumption used in cooling of residential building decreases. Recommendations indicate to the need to study the building services positions in the new projects progress to select the best alternatives to realize ‘Energy conservation’ used in cooling or heating into the buildings in general, residential buildings particularly.

Keywords: residential buildings, energy conservation, thermal comfort, building services, temporary used service spaces, DesignBuilder

Procedia PDF Downloads 277

Authors: Stacia E. H. Sitohang, S.Mn., Socrates Rudy Sirait

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The first movie theater in Indonesia was established in December 1900. The movie industry started with international movie penetration. After a while, local movie producers started to rise and created local Indonesian movies. The industry is growing through ups and downs in Indonesia. In 2008, Visinema was founded in Jakarta, Indonesia, by AnggaDwimasSasongko, one of the most respected movie director in Indonesia. After getting achievements and recognition, Visinema chose to grow the company horizontally as opposed to only grow vertically and gain another similar achievement. Visinemachose to build the ecosystem that enables them to obtain many more opportunities and generatebusiness sustainability. The company proceed as an agile company. They created several business subsidiaries to support the company’s Intellectual Property (IP) development. This research was done through interview with the key persons in the company and questionnaire to get market insights regarding Visinema. The is able to transform their IP that initially started from movies to different kinds of business model. Interestingly, Angga chose to use the start up approach to create Visinema. In 2019, the company successfully gained Series A funding from Intudo Ventures and got other various investment schemes to support the business. In early 2020, Covid-19 pandemic negatively impacted many industries in Indonesia, especially the entertainment and leisure businesses. Fortunately, Visinema did not face any significant problem regarding survival during the pandemic, there were nolay-offs nor work hour reductions. Instead, they were thinking of much bigger opportunities and problems. While other companies suffer during the pandemic, Visinema created the first focused Transactional Video On Demand (TVOD) in Indonesia named Bioskop Online. The platform was created to keep the company innovating and adapting with the new online market as the result of the Covid-19 pandemic. Other than a digital platform, Visinemainvested heavily in animation to target kids and family business. They believed that penetrating the technology and animation market is going to be the biggest opportunity in Visinema’s road map. Besides huge opportunities, Visinema is also facing problems. The first is company brand positioning. Angga, as the founder, felt the need to detach his name from the brand image of Visinema to create system sustainability and scalability. Second, the company has to create a strategy to refocus in a particular business area to maintain and improve the competitive advantages. The third problem, IP piracy is a huge structural problem in Indonesia, the company considers IP thieves as their biggest competitors as opposed to other production company. As the recommendation, we suggest a set of branding and management strategy to detach the founder’s name from Visinema’s brand and improve the competitive advantages. We also suggest Visinema invest in system building to prevent IP piracy in the entertainment industry, which later can be another business subsidiary of Visinema.

Keywords: business ecosystem, agile, sustainability, scalability, start Up, intellectual property, digital platform

Procedia PDF Downloads 129

Authors: Hacer Sule Gonul, Vedat Uyak

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Intensive use of pesticides in agricultural activity causes mixing of these compounds into water sources with surface flow. Especially after the 1970s, a number of limitations imposed on the use of chlorinated pesticides that have a carcinogenic risk potential and regulatory limit have been established. These chlorinated pesticides discharge to water resources, transport in the water and land environment and accumulation in the human body through the food chain raises serious health concerns. Carbon nanotubes (CNTs) have attracted considerable attention from on all because of their excellent mechanical, electrical, and environmental characteristics. Due to CNT particles' high degree of hydrophobic surfaces, these nanoparticles play critical role in the removal of water contaminants of natural organic matters, pesticides and phenolic compounds in water sources. Health concerns associated with chlorinated pesticides requires the removal of such contaminants from aquatic environment. Although the use of aldrin and atrazine was restricted in our country, repatriation of illegal entry and widespread use of such chemicals in agricultural areas cause increases for the concentration of these chemicals in the water supply. In this study, the compounds of chlorinated pesticides such as aldrin and atrazine compounds would be tried to eliminate from drinking water with carbon nanotube adsorption method. Within this study, 2 different types of CNT would be used including single-wall (SWCNT) and multi-wall (MWCNT) carbon nanotubes. Adsorption isotherms within the scope of work, the parameters affecting the adsorption of chlorinated pesticides in water are considered as pH, contact time, CNT type, CNT dose and initial concentration of pesticides. As a result, under conditions of neutral pH conditions with MWCNT respectively for atrazine and aldrin obtained adsorption capacity of determined as 2.24 µg/mg ve 3.84 µg/mg. On the other hand, the determined adsorption capacity rates for SWCNT for aldrin and atrazine has identified as 3.91 µg/mg ve 3.92 µg/mg. After all, each type of pesticide that provides superior performance in relieving SWCNT particles has emerged.

Keywords: pesticide, drinking water, carbon nanotube, adsorption

Procedia PDF Downloads 160

Authors: Hatice Torcu Koc, Zeliha Erdogan

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This study presented the investigation of the population structure of Upeneus moluccensis in order to provide further knowledge and to compare the data with the studies before and thus help in the management of the population in the İskenderun Bay. For this purpose, a total of 370 golden-banded goatfish were caught by a commercial vessel monthly at a depth of 50-60 m. from İskenderun Bay in the years 2016-2018. Von Bertalanffy growth equation,length-weight relationships, sex ratio, age, condition, and gonado and hepato-somatic index values of U.peneus moluccensis specimens were determined. For this, the lengths and weights were measured using a dial caliper of 0.05 mm and a sensitive balance. Total lengths were 7.2–17.5 cm in females and 7.0–17.9 cm in males, while total weight ranges for females and males were 3.91-64.26 g and 3.69-60.95 g., respectively. Length-weight relationship for all individuals was calculated as W=0.004*L³ ³⁸, R²=0.85. Growth parameter was determined as L∞= 20.75 cm, k=0.33, t₀= - 0.56. The age readings were done by using the Bhattacharya method. The population was composed of 3 ages (1-3). The sex ratio was found as 1:1.42, corresponding to 41.4% males and 58.6% females, in favor of females (p<0.05). Values of the average condition and hepatosomatic index were found to be shown a similar pattern for males (1.088, 1.104) and females (1.124, 1.177), respectively. According to GSI values, the spawning period started in March and increased to April, May, and September. It was estimated that total (Z) mortality, natural (M) mortality, and fishing (F) mortality rates were estimated as Z=0.94 year-¹, M=0.033 year-¹, and F=0.63 year-¹, respectively. As the exploitation rate was estimated to be E=0.67, it can be shown that the golden-banded goatfish stock was influenced by overfishing. The findings of this study are very important to point out the population of U. moluccensis, which penetrated into the eastern Mediterranean Sea of Türkiye due to global heating and the construction of the Suez Canal and to be basic data for the next fisheries investigations.

Keywords: biology, U. moluccensis, invasive, lessepsian, İskenderun Bay

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Authors: L. Shafiq, A. Rigby

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All polyethylene processes are highly exothermic, and the safe removal of the heat of reaction is a fundamental issue in the process design. In slurry and gas processes, the velocity of the polymer particles in the reactor and external coolers can be very high, and under certain conditions, this can lead to static charging of these particles. Such static charged polymer particles may start building up on the reactor wall, limiting heat transfer, and ultimately leading to severe reactor fouling and forced reactor shut down. Statsafe™ is an FDA approved anti-fouling additive currently used around the world for polyolefin production as an anti-fouling additive. The unique polymer chemistry aids static discharge, which prevents the build-up of charged polyolefin particles, which could lead to fouling. Statsafe™ is being used and trailed in gas, slurry, and a combination of these technologies around the world. We will share data to demonstrate how the use of Statsafe™ allows more stable operation at higher solids level by eliminating static, which would otherwise prevent closer packing of particles in the hydrocarbon slurry. Because static charge generation depends also on the concentration of polymer particles in the slurry, the maximum slurry concentration can be higher when using Statsafe™, leading to higher production rates. The elimination of fouling also leads to less downtime. Special focus will be made on the impact anti-static additives have on catalyst performance within the polymerization process and how this has been measured. Lab-scale studies have investigated the effect on the activity of Ziegler Natta catalysts when anti-static additives are used at various concentrations in gas and slurry, polyethylene and polypropylene processes. An in-depth gas phase study investigated the effect of additives on the final polyethylene properties such as particle size, morphology, fines, bulk density, melt flow index, gradient density, and melting point.

Keywords: anti-static additives, catalyst performance, FDA approved anti-fouling additive, polymerisation

Procedia PDF Downloads 191

Authors: Ndiaye Mouhamadou, Seck Abdoulaye, Ndiaye Babacar, Diallo Thierno Abdoulaye, Diop Abdou, Seck Mame Cheikh, Diongue Khadim, Badiane Aida Sadikh, Diallo Mamadou Alpha, Kouedvidjin Ekoué, Ndiaye Daouda

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Background: Toxoplasmosis is a parasite disease that presents high rates of gestational and congenital infection worldwide and is therefore considered a public health problem and a neglected disease. The aim of this study was to determine the seroprevalence of toxoplasmosis in pregnant women referred to the medical biology laboratory of the Pasteur Institute of Dakar (Senegal) between January 2014 and December 2019. Methodology: This was a cross-sectional, descriptive, retrospective study of 10892 blood samples from pregnant women aged 16 to 46 years. The Architect toxo IgG/IgM from Abbot Laboratories, which is a chemiluminescent microparticle immunoassay (CMIA), was used for the quantitative determination of antibodies against Toxoplasma gondii in human serum. Results: In total, over a period from January 2014 to December 2019, 10892 requests for toxoplasmosis serology in pregnant women were included. The age of the patients included in our series ranged from 16 to 46 years. The mean age was 31.2 ± 5.72 years. The overall seroprevalence of T. gondii in pregnant women was estimated to be 28.9% [28.0-29.7]. In a multivariate logistic regression analysis, after adjustment for a covariate such as a study period, pregnant women aged 36-46 years were more likely to carry IgG antibodies to T. gondii than pregnant women younger than 36 years. Conclusion: T. gondii seroprevalence was significantly higher in pregnant women older than 36 years, leaving younger women more susceptible to primary T. gondii infection and their babies to congenital toxoplasmosis. There will be a need to increase awareness of the risk factors for toxoplasmosis and its different modes of transmission in these high-risk groups, but this should be supported by epidemiologic studies of the distribution of risk factors for toxoplasmosis in pregnant women and women of childbearing age.

Keywords: toxoplasmosis, pregnancy, seroprevalence, Senegal

Procedia PDF Downloads 125

Authors: Mayandi Ramanathan

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Gas turbine blades see the most aggressive thermal stress conditions within the engine, due to high Turbine Entry Temperatures in the range of 1500 to 1600°C. The blades rotate at very high rotation rates and remove a significant amount of thermal power from the gas stream. At high temperatures, the major component failure mechanism is a creep. During its service over time under high thermal loads, the blade will deform, lengthen and rupture. High strength and stiffness in the longitudinal direction up to elevated service temperatures are certainly the most needed properties of turbine blades and gas turbine components. The proposed advanced Ti alloy material needs a process that provides a strategic orientation of metallic ordering, uniformity in composition and high metallic strength. The chemical composition of the proposed Ti alloy material (25% Ta/(Al+Ta) ratio), unlike Ti-47Al-2Cr-2Nb, has less excess Al that could limit the service life of turbine blades. Properties and performance of Ti-47Al-2Cr-2Nb and Ti-6Al-4V materials will be compared with that of the proposed Ti alloy material to generalize the performance metrics of various gas turbine components. This paper will involve the summary of the effects of additive manufacturing and heat treatment process conditions on the changes in the phase composition, grain structure, lattice structure of the material, tensile strength, creep strain rate, thermal expansion coefficient and fracture toughness at different temperatures. Based on these results, additive manufacturing and heat treatment process conditions will be optimized to fabricate turbine blade with Ti-43Al matrix alloyed with an optimized amount of refractory Ta metal. Improvement in service temperature of the turbine blades and corrosion resistance dependence on the coercivity of the alloy material will be reported. A correlation of phase composition and creep strain rate will also be discussed.

Keywords: high temperature materials, aerospace, specific strength, creep strain, phase composition

Procedia PDF Downloads 107

Authors: Siddarth Kannan

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Objectives: Deep Brain Stimulation (DBS) and Motor Cortex stimulation (MCS) are innovative interventions in order to treat various neuropathic pain disorders such as post-stroke pain. While each treatment has a varying degree of success in managing pain, comparative analysis has not yet been performed, and the success rates of these techniques using validated, objective pain scores have not been synthesised. The aim of this study was to compare the effect of pain relief offered by MCS and DBS on patients with post-stroke pain and to assess if either of these procedures offered better results. Methods: A systematic review and meta-analysis were conducted in accordance with PRISMA guidelines (PROSPEROID CRD42021277542). Three databases were searched, and articles published from 2000 to June 2023 were included (last search date 25 June 2023). Meta-analysis was performed using random effects models. We evaluated the performance of DBS or MCS by assessing studies that reported pain relief using the Visual Analogue Scale (VAS). Data analysis of descriptive statistics was performed using SPSS (Version 27; IBM; Armonk; NY; USA). R statistics (Rstudio Version 4.0.1) was used to perform meta-analysis. Results: Of the 478 articles identified, 27 were included in the analysis (232 patients- 117 DBS & 115 MCS). The pooled number of patients who improved after DBS was 0.68 (95% CI, 0.57-0.77, I2=36%). The pooled number of patients who improved after MCS was 0.72 (95% CI, 0.62-0.80, I2=59%). Further sensitivity analysis was done to include only studies with a minimum of 5 patients in order to assess if there was any impact on the overall results. Nine studies each for DBS and MCS met these criteria. There seemed to be no significant difference in results. Conclusions: The use of surgical interventions such as DBS and MCS is an upcoming field for the treatment of post-stroke pain, with limited studies exploring and comparing these two techniques. While our study shows that MCS might be a slightly better treatment option, further research would need to be done in order to determine the appropriate surgical intervention for post-stroke pain.

Keywords: post-stroke pain, deep brain stimulation, motor cortex stimulation, pain relief

Procedia PDF Downloads 120

Authors: Robin Molinier

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Industrial symbiosis (I.S) rely on two modes of cooperation that are infrastructure sharing and resource substitution to obtain economic and environmental benefits. The former consists in the intensification of use of an asset while the latter is based on the use of waste, fatal energy (and utilities) as alternatives to standard inputs. Both modes, in fact, rely on the shift from a business-as-usual functioning towards an alternative production system structure so that in a business point of view the distinction is not clear. In order to investigate the way those cooperation modes can be distinguished, we consider the stakeholders' interplay in the business model structure regarding their resources and requirements. For infrastructure sharing (following economic engineering literature) the cost function of capacity induces economies of scale so that demand pooling reduces global expanses. Grassroot investment sizing decision and the ex-post pricing strongly depends on the design optimization phase for capacity sizing whereas ex-post operational cost sharing minimizing budgets are less dependent upon production rates. Value is then mainly design driven. For resource substitution, synergies value stems from availability and is at risk regarding both supplier and user load profiles and market prices of the standard input. Baseline input purchasing cost reduction is thus more driven by the operational phase of the symbiosis and must be analyzed within the whole sourcing policy (including diversification strategies and expensive back-up replacement). Moreover, while resource substitution involves a chain of intermediate processors to match quality requirements, the infrastructure model relies on a single operator whose competencies allow to produce non-rival goods. Transaction costs appear higher in resource substitution synergies due to the high level of customization which induces asset specificity, and non-homogeneity following transaction costs economics arguments.

Keywords: business model, capacity, sourcing, synergies

Procedia PDF Downloads 169

Authors: Hannah Dean

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The growth ideology, and its association with progress, is an important construct in the narrative of modernity. This ideology is embedded in neoclassical economic growth theory which conceptualises growth as linear and predictable, and the entrepreneur as a rational economic manager. This conceptualisation has been critiqued for reinforcing the managerial discourse in entrepreneurship studies. Despite these critiques, both the neoclassical growth theory and its adjacent managerial discourse dominate entrepreneurship studies notably the literature on female entrepreneurs. The latter is the focus of this paper. Given this emphasis on growth, female entrepreneurs are portrayed as problematic because their growth lags behind their male counterparts. This image which ignores the complexity and diversity of female entrepreneurs’ experience persists in the literature due to the lack of studies that analyse the process and contextual factors surrounding female entrepreneurs’ experience. This study aims to address the subordination of female entrepreneurs by questioning the hegemonic logic of economic growth and the managerial discourse as a true representation for the entrepreneurial experience. This objective is achieved by drawing on Schumpeter’s theorising and narrative inquiry. This exploratory study undertakes in depth interviews to gain insights into female entrepreneurs’ experience and the impact of the economic growth model and the managerial discourse on their performance. The narratives challenge a number of assumptions about female entrepreneurs. The participants occupied senior positions in the corporate world before setting up their businesses. This is at odds with much writing which assumes that women underperform because they leave their career without gaining managerial experience to achieve work-life balance. In line with Schumpeter, who distinguishes the entrepreneur from the manager, the participants’ main function was innovation. They did not believe that the managerial paradigm governing their corporate careers was applicable to their entrepreneurial experience. Formal planning and managerial rationality can hinder their decision making process. The narratives point to the gap between the two worlds which makes stepping into entrepreneurship a scary move. Schumpeter argues that the entrepreneurial process is evolutionary and that failure is an integral part of it. The participants’ entrepreneurial process was in fact irregular. The performance of new combinations was not always predictable. They therefore relied on their initiative. The inhibition to deploy these traits had an adverse effect on business growth. The narratives also indicate that over-reliance on growth threaten the business survival as it faces competing pressures. The study offers theoretical and empirical contributions to (female) entrepreneurship studies by presenting Schumpeter’s theorising as an alternative theoretical framework to the neoclassical economic growth theory. The study also reduces entrepreneurs’ vulnerability by making them aware of the negative influence that the linear growth model and the managerial discourse hold upon their performance. The study has implications for policy makers as it generates new knowledge that incorporates the current social and economic changes in the context of entrepreneurs that can no longer be sustained by the linear growth models especially in the current economic climate.

Keywords: economic growth, female entrepreneurs, managerial discourse, Schumpeter

Procedia PDF Downloads 286

Authors: Marzieh Khezerloo, Lyazid Djenidi

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Owing to wide range of the micro-device applications, the problems of mixing at small scales is of significant interest. Also, because most of the processes produce heat, it is needed to develop and implement strategies for heat removal in these devices. There are many studies which focus on the effect of roughness or suction on heat transfer performance, separately, although it would be useful to take advantage of these two methods to improve heat transfer performance. Unfortunately, there is a gap in this area. The present numerical study is carried to investigate the combined effects of roughness and wall suction on heat transfer performance of a laminar channel flow; suction is applied on the top and back faces of the roughness element, respectively. The study is carried out for different Reynolds numbers, different suction rates, and various locations of suction area on the roughness. The flow is assumed two dimensional, incompressible, laminar, and steady state. The governing Navier-Stokes equations are solved using ANSYS-Fluent 18.2 software. The present results are tested against previous theoretical results. The results show that by adding suction, the local Nusselt number is enhanced in the channel. In addition, it is shown that by applying suction on the bottom section of the roughness back face, one can reduce the thickness of thermal boundary layer, which leads to an increase in local Nusselt number. This indicates that suction is an effective means for improving the heat transfer rate (suction by controls the thickness of thermal boundary layer). It is also shown that the size and intensity of vortical motion behind the roughness element, decreased with an increasing suction rate, which leads to higher local Nusselt number. So, it can be concluded that by using suction, strategically located on the roughness element, one can control both the recirculation region and the heat transfer rate. Further results will be presented at the conference for coefficient of drag and the effect of adding more roughness elements.

Keywords: heat transfer, laminar flow, numerical simulation, roughness, suction

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Authors: D. O. Ramadan, R. S. Dwyer-Joyce

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The measurement of the interface conditions in a cutting tool contact is essential information for performance monitoring and control. This interface provides the path for the heat flux to the cutting tool. This elevate in the cutting tool temperature leads to motivate the mechanism of tool wear, thus affect the life of the cutting tool and the productivity. This zone is representative by the tool-chip interface. Therefore, understanding and monitoring this interface is considered an important issue in machining. In this paper, an acoustic emission (AE) technique was used to find the correlation between AE parameters and the tool-chip interface. For this reason, a response surface design (RSD) has been used to analyse and optimize the machining parameters. The experiment design was based on the face centered, central composite design (CCD) in the Minitab environment. According to this design, a series of orthogonal cutting experiments for different cutting conditions were conducted on a Triumph 2500 lathe machine to study the sensitivity of the acoustic emission (AE) signal to change in tool-chip contact length. The cutting parameters investigated were the cutting speed, depth of cut, and feed and the experiments were performed for 6082-T6 aluminium tube. All the orthogonal cutting experiments were conducted unlubricated. The tool-chip contact area was investigated using a scanning electron microscope (SEM). The results obtained in this paper indicate that there is a strong dependence of the root mean square (RMS) on the cutting speed, where the RMS increases with increasing the cutting speed. A dependence on the tool-chip contact length has been also observed. However there was no effect observed of changing the cutting depth and feed on the RMS. These dependencies have been clarified in terms of the strain and temperature in the primary and secondary shear zones, also the tool-chip sticking and sliding phenomenon and the effect of these mechanical variables on dislocation activity at high strain rates. In conclusion, the acoustic emission technique has the potential to monitor in situ the tool-chip interface in turning and consequently could indicate the approaching end of life of a cutting tool.

Keywords: Acoustic emission, tool-chip interface, orthogonal cutting, monitoring

Procedia PDF Downloads 477

Authors: Mark Linden, Rachel Leonard, Trisha Forbes, Michael Brown, Lynne Marsh, Stuart Todd, Nathan Hughes, Maria Truesdale

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Background: Current interventions which aim to improve the mental health of family carers are often face to face, which can create barriers to full participation. Online interventions can offer flexibility in delivery compared to face to face approaches. The primary objective of this study is to determine the feasibility of delivering the Carers-ID online intervention, while the secondary outcome is to improve the mental health of family carers of people with intellectual disabilities. Methods: Family carers (n = 120) will be randomised to receive the intervention (n=60) or assigned to a wait-list control (n=60) group. The intervention (www.Carers-ID.com) consists of fourteen modules which cover topics including promoting resilience, providing peer support, reducing anxiety, managing stress, accessing local supports, managing family conflict and information for siblings who are carers. Primary outcomes for this study include acceptability and feasibility of the outcome measures, recruitment, participation and retention rates and effect sizes. Secondary outcomes will be completed at three time points (baseline, following intervention completion and three months after completion). Secondary outcomes include, depression, anxiety, stress, well-being , resilience and social connectedness. Participants (n=12) who have taken part in the intervention arm of the research will be invited to participate in semi-structured interviews as part of the process evaluation. Discussion: To determine whether a full-scale randomised controlled effectiveness trial is warranted, feasibility testing of the intervention and trial procedures is a necessary first step. The Carers-ID intervention provides an accessible resource for family carers to support their mental health and well-being.

Keywords: intellectual disability, family carer, feasibility trial, online intervention

Procedia PDF Downloads 61