Search results for: stress rate
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 11360

Search results for: stress rate

3320 Response of Planktonic and Aggregated Bacterial Cells to Water Disinfection with Photodynamic Inactivation

Authors: Thayse Marques Passos, Brid Quilty, Mary Pryce

Abstract:

The interest in developing alternative techniques to obtain safe water, free from pathogens and hazardous substances, is growing in recent times. The photodynamic inactivation of microorganisms (PDI) is a promising ecologically-friendly and multi-target approach for water disinfection. It uses visible light as an energy source combined with a photosensitiser (PS) to transfer energy/electrons to a substrate or molecular oxygen generating reactive oxygen species, which cause cidal effects towards cells. PDI has mainly been used in clinical studies and investigations on its application to disinfect water is relatively recent. The majority of studies use planktonic cells. However, in their natural environments, bacteria quite often do not occur as freely suspended cells (planktonic) but in cell aggregates that are either freely floating or attached to surfaces as biofilms. Microbes can form aggregates and biofilms as a strategy to protect them from environmental stress. As aggregates, bacteria have a better metabolic function, they communicate more efficiently, and they are more resistant to biocide compounds than their planktonic forms. Among the bacteria that are able to form aggregates are members of the genus Pseudomonas, they are a very diverse group widely distributed in the environment. Pseudomonas species can form aggregates/biofilms in water and can cause particular problems in water distribution systems. The aim of this study was to evaluate the effectiveness of photodynamic inactivation in killing a range of planktonic cells including Escherichia coli DSM 1103, Staphylococcus aureus DSM 799, Shigella sonnei DSM 5570, Salmonella enterica and Pseudomonas putida DSM 6125, and aggregating cells of Pseudomonas fluorescens DSM 50090, Pseudomonas aeruginosa PAO1. The experiments were performed in glass Petri dishes, containing the bacterial suspension and the photosensitiser, irradiated with a multi-LED (wavelengths 430nm and 660nm) for different time intervals. The responses of the cells were monitored using the pour plate technique and confocal microscopy. The study showed that bacteria belonging to Pseudomonads group tend to be more tolerant to PDI. While E. coli, S. aureus, S. sonnei and S. enterica required a dosage ranging from 39.47 J/cm2 to 59.21 J/cm2 for a 5 log reduction, Pseudomonads needed a dosage ranging from 78.94 to 118.42 J/cm2, a higher dose being required when the cells aggregated.

Keywords: bacterial aggregation, photoinactivation, Pseudomonads, water disinfection

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3319 The Prevalence of Obesity among a Huge Sample of 5-20 Years Old Jordanian Children and Adolescents Based on CDC Criteria

Authors: Walid Al-Qerem, Ruba Zumot

Abstract:

Background: The rise of obesity among children and adolescents remains a primary challenge for healthcare providers globally and in the Middle East. The aim of the present study is to determine the prevalence of obesity among 5-20 years old Jordanians based on CDC criteria. Method: A total of 5722 Jordanians (37% males; 63% females) aged 5-20 years data were retrieved from the Jordanian Ministry of Health electronic database (Hakeem). As per the CDC selection criteria, the chosen data pertains exclusively to healthy Jordanian children and adolescents who are medically sound, not suffering from health conditions, and not undergoing any treatments that could hinder normal growth patterns, such as severe infection, chronic kidney disease (CKD), Down’s syndrome, attention deficit hyperactivity disorder, cancer, heart disease, lung disease, cystic fibrosis, Crohn’s disease, type 1 diabetes, hormonal disturbances, any stress-related conditions, hormonal therapy such as corticosteroids, Growth hormones (GHS) or gonadotropin-releasing hormone agonists, insulin, and amphetamines or any other stimulants. In addition, participants with missing or invalid data values for anthropometric measurements were excluded from the study. Weight for age and body mass index for age were analyzed comparatively for Jordanian children and adolescents against the international growth standards. The Z-score for each record was computed based on CDC equations. As per CDC classifications, BMI for age percentiles, values ≥85th and < 95th are classified as overweight, and value at ≥ 95th is classified as obesity. Results: The average age of the evaluated sample was 12.33 ±4.39 years (10.79 ±3.39 for males and 13.23 ± 4.66 for females). The mean weight for males and females were 33.16±14.17 Kg and 133.54±17.17 cm for males, 43.86 ±18.82 Kg, and 142.19±18.35 for females, while for BMI the mean was for boys and girls 17.81±3.88 and 20.52±5.03 respectively. The results indicated that based on CDC criteria, 8.9% of males were classified as children/adolescents with overweight, and 9.7% were classified as children/adolescents with obesity, while in females, 17.8% were classified as children/adolescents with overweight and 10.2% were classified as children/adolescents with obesity. Discussion: The high prevalence of obesity reported in the present study emphasizes the importance of applying different strategies to prevent childhood obesity, including encouraging physical activity, promoting healthier food options, and behavioral changes. Conclusion: The results presented in this study indicated the high prevalence of overweight/obesity among Jordanian adolescents and children, which must be tagged by healthcare planners and providers.

Keywords: CDC, obesity, childhood, Jordan

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3318 Production Planning for Animal Food Industry under Demand Uncertainty

Authors: Pirom Thangchitpianpol, Suttipong Jumroonrut

Abstract:

This research investigates the distribution of food demand for animal food and the optimum amount of that food production at minimum cost. The data consist of customer purchase orders for the food of laying hens, price of food for laying hens, cost per unit for the food inventory, cost related to food of laying hens in which the food is out of stock, such as fine, overtime, urgent purchase for material. They were collected from January, 1990 to December, 2013 from a factory in Nakhonratchasima province. The collected data are analyzed in order to explore the distribution of the monthly food demand for the laying hens and to see the rate of inventory per unit. The results are used in a stochastic linear programming model for aggregate planning in which the optimum production or minimum cost could be obtained. Programming algorithms in MATLAB and tools in Linprog software are used to get the solution. The distribution of the food demand for laying hens and the random numbers are used in the model. The study shows that the distribution of monthly food demand for laying has a normal distribution, the monthly average amount (unit: 30 kg) of production from January to December. The minimum total cost average for 12 months is Baht 62,329,181.77. Therefore, the production planning can reduce the cost by 14.64% from real cost.

Keywords: animal food, stochastic linear programming, aggregate planning, production planning, demand uncertainty

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3317 Biomass and Biogas Yield of Maize as Affected by Nitrogen Rates with Varying Harvesting under Semi-Arid Condition of Pakistan

Authors: Athar Mahmood, Asad Ali

Abstract:

Management considerations including harvesting time and nitrogen application considerably influence the biomass yield, quality and biogas production. Therefore, a field study was conducted to determine the effect of various harvesting times and nitrogen rates on the biomass yield, quality and biogas yield of maize crop. This experiment was consisted of various harvesting times i.e., harvesting after 45, 55 and 65 days of sowing (DAS) and nitrogen rates i.e., 0, 100, 150 and 200 kg ha-1 respectively. The data indicated that maximum plant height, leaf area, dry matter (DM) yield, protein, acid detergent fiber, neutral detergent fiber, crude fiber contents and biogas yield were recorded 65 days after sowing while lowest was recorded 45 days after sowing. In contrary to that significantly higher chlorophyll contents were observed at 45 DAS. In case of nitrogen rates maximum plant height, leaf area, and DM yield, protein contents, ash contents, acid detergent fiber, neutral detergent fiber, crude fiber contents and chlorophyll contents were determined with nitrogen at the rate of 200 kg ha-1, while minimum was observed when no N was applied. Therefore, harvesting 65 DAS and N application @ 200 kg ha-1 can be suitable for getting the higher biomass and biogas production.

Keywords: chemical composition, fiber contents, biogas, nitrogen, harvesting time

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3316 The Impact of Management Competency, Project Team, and Process Design to Corporate Performance through Implementing the Self-Development ERP

Authors: Zeplin Jiwa Husada Tarigan, Sautma Ronni Basana, Widjojo Suprapto

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Manufacturing companies in East Java develop their own ERP system or alter the ERP system which is developed by other companies to suit their needs. To make their own system, the companies mostly assign several employees from various departments to create a project team, and the employees are from the departments that are going to utilize the ERP system as the integrated data. The project team decides the making of the ERP system from the preparation stage until the going live implementation process. In designing the business process, the top management is working together with the project team until the project is accomplished. The completion of the ERP projects depends on the project to be undertaken itself, the strategy chosen to complete the project, the work method selection, the measurement system to monitor the project, the evaluation system of the project, and, in the end, the declaration of 'going live' of the ERP project. There is an increase in the business performance for the companies that have implemented the information technology or ERP as they manage to integrate all management functions within their companies. To investigate, some questionnaires are distributed to 100 manufacturing companies, and 90 questionnaires are returned; however, there are only 46 companies that develop their own ERP system, so the response rate is 46%. The result of data analysis using PLS shows that the management competency brings impacts to the project team and the process design. The process design is adjusted to the real process in order to implement the ERP, but it does not bring direct impacts to the business performance. The implementation of ERP brings positive impacts to the company business performance.

Keywords: management competency, project team, process design, ERP implementation, business performance

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3315 Control System Design for a Simulated Microbial Electrolysis Cell

Authors: Pujari Muruga, T. K. Radhakrishnan, N. Samsudeen

Abstract:

Hydrogen is considered as the most important energy carrier and fuel of the future because of its high energy density and zero emission properties. Microbial Electrolysis Cell (MEC) is a new and promising approach for hydrogen production from organic matter, including wastewater and other renewable resources. By utilizing anode microorganism activity, MEC can produce hydrogen gas with smaller voltages (as low as 0.2 V) than those required for electrolytic hydrogen production ( ≥ 1.23 V). The hydrogen production processes of the MEC reactor are very nonlinear and highly complex because of the presence of microbial interactions and highly complex phenomena in the system. Increasing the hydrogen production rate and lowering the energy input are two important challenges of MEC technology. The mathematical model of the MEC is based on material balance with the integration of bioelectrochemical reactions. The main objective of the research is to produce biohydrogen by selecting the optimum current and controlling applied voltage to the MEC. Precise control is required for the MEC reactor, so that the amount of current required to produce hydrogen gas can be controlled according to the composition of the substrate in the reactor. Various simulation tests involving multiple set-point changes disturbance and noise rejection were performed to evaluate the performance using PID controller tuned with Ziegler Nichols settings. Simulation results shows that other good controller can provide better control effect on the MEC system, so that higher hydrogen production can be obtained.

Keywords: microbial electrolysis cell, hydrogen production, applied voltage, PID controller

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3314 Alumina Supported Cu-Mn-Cr Catalysts for CO and VOCs oxidation

Authors: Krasimir Ivanov, Elitsa Kolentsova, Dimitar Dimitrov, Petya Petrova, Tatyana Tabakova

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This work studies the effect of chemical composition on the activity and selectivity of γ–alumina supported CuO/ MnO2/Cr2O3 catalysts toward deep oxidation of CO, dimethyl ether (DME) and methanol. The catalysts were prepared by impregnation of the support with an aqueous solution of copper nitrate, manganese nitrate and CrO3 under different conditions. Thermal, XRD and TPR analysis were performed. The catalytic measurements of single compounds oxidation were carried out on continuous flow equipment with a four-channel isothermal stainless steel reactor. Flow-line equipment with an adiabatic reactor for simultaneous oxidation of all compounds under the conditions that mimic closely the industrial ones was used. The reactant and product gases were analyzed by means of on-line gas chromatographs. On the basis of XRD analysis it can be concluded that the active component of the mixed Cu-Mn-Cr/γ–alumina catalysts consists of at least six compounds – CuO, Cr2O3, MnO2, Cu1.5Mn1.5O4, Cu1.5Cr1.5O4 and CuCr2O4, depending on the Cu/Mn/Cr molar ratio. Chemical composition strongly influences catalytic properties, this influence being quite variable with regards to the different processes. The rate of CO oxidation rapidly decrease with increasing of chromium content in the active component while for the DME was observed the reverse trend. It was concluded that the best compromise are the catalysts with Cu/(Mn + Cr) molar ratio 1:5 and Mn/Cr molar ratio from 1:3 to 1:4.

Keywords: Cu-Mn-Cr oxide catalysts, volatile organic compounds, deep oxidation, dimethyl ether (DME)

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3313 Prediction Factor of Recurrence Supraventricular Tachycardia After Adenosine Treatment in the Emergency Department

Authors: Chaiyaporn Yuksen

Abstract:

Backgroud: Supraventricular tachycardia (SVT) is an abnormally fast atrial tachycardia characterized by narrow (≤ 120 ms) and constant QRS. Adenosine was the drug of choice; the first dose was 6 mg. It can be repeated with the second and third doses of 12 mg, with greater than 90% success. The study found that patients observed at 4 hours after normal sinus rhythm was no recurrence within 24 hours. The objective of this study was to investigate the factors that influence the recurrence of SVT after adenosine in the emergency department (ED). Method: The study was conducted retrospectively exploratory model, prognostic study at the Emergency Department (ED) in Faculty of Medicine, Ramathibodi Hospital, a university-affiliated super tertiary care hospital in Bangkok, Thailand. The study was conducted for ten years period between 2010 and 2020. The inclusion criteria were age > 15 years, visiting the ED with SVT, and treating with adenosine. Those patients were recorded with the recurrence SVT in ED. The multivariable logistic regression model developed the predictive model and prediction score for recurrence PSVT. Result: 264 patients met the study criteria. Of those, 24 patients (10%) had recurrence PSVT. Five independent factors were predictive of recurrence PSVT. There was age>65 years, heart rate (after adenosine) > 100 per min, structural heart disease, and dose of adenosine. The clinical risk score to predict recurrence PSVT is developed accuracy 74.41%. The score of >6 had the likelihood ratio of recurrence PSVT by 5.71 times Conclusion: The clinical predictive score of > 6 was associated with recurrence PSVT in ED.

Keywords: clinical prediction score, SVT, recurrence, emergency department

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3312 Evaluation of Different Fertilization Practices and Their Impacts on Soil Chemical and Microbial Properties in Two Agroecological Zones of Ghana

Authors: Ansong Richard Omari, Yosei Oikawa, Yoshiharu Fujii, Dorothea Sonoko Bellingrath-Kimura

Abstract:

Renewed interest in soil management aimed at improving the productive capacity of Sub Saharan Africa (SSA) soils has called for the need to analyse the long term effect of different fertilization systems on soil. This study was conducted in two agroecological zones (i.e., Guinea Savannah (GS) and Deciduous forest (DF)) of Ghana to evaluate the impacts of long term (> 5 years) fertilization schemes on soil chemical and microbial properties. Soil samples under four different fertilization schemes (inorganic, inorganic and organic, organic, and no fertilization) were collected from 20 farmers` field in both agroecological zones. Soil analyses were conducted using standard procedures. All average soil quality parameters except extractable C, potential mineralizable nitrogen and CEC were significantly higher in DF sites compared to GS. Inorganic fertilization proved superior in soil chemical and microbial biomass especially in GS zone. In GS, soil deterioration index (DI) revealed that soil quality deteriorated significantly (−26%) under only organic fertilization system whereas soil improvement was observed under inorganic and no fertilization sites. In DF, either inorganic or organic and inorganic fertilization showed significant positive effects on soil quality. The high soil chemical composition and enhanced microbial biomass in DF were associated with the high rate of inorganic fertilization.

Keywords: deterioration index, fertilization scheme, microbial biomass, tropical agroecological zone

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3311 Object-Based Flow Physics for Aerodynamic Modelling in Real-Time Environments

Authors: William J. Crowther, Conor Marsh

Abstract:

Object-based flow simulation allows fast computation of arbitrarily complex aerodynamic models made up of simple objects with limited flow interactions. The proposed approach is universally applicable to objects made from arbitrarily scaled ellipsoid primitives at arbitrary aerodynamic attitude and angular rate. The use of a component-based aerodynamic modelling approach increases efficiency by allowing selective inclusion of different physics models at run-time and allows extensibility through the development of new models. Insight into the numerical stability of the model under first order fixed-time step integration schemes is provided by stability analysis of the drag component. The compute cost of model components and functions is evaluated and compared against numerical benchmarks. Model static outputs are verified against theoretical expectations and dynamic behaviour using falling plate data from the literature. The model is applied to a range of case studies to demonstrate the efficacy of its application in extensibility, ease of use, and low computational cost. Dynamically complex multi-body systems can be implemented in a transparent and efficient manner, and we successfully demonstrate large scenes with hundreds of objects interacting with diverse flow fields.

Keywords: aerodynamics, real-time simulation, low-order model, flight dynamics

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3310 Clinical and Sleep Features in an Australian Population Diagnosed with Mild Cognitive Impairment

Authors: Sadie Khorramnia, Asha Bonney, Kate Galloway, Andrew Kyoong

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Sleep plays a pivotal role in the registration and consolidation of memory. Multiple observational studies have demonstrated that self-reported sleep duration and sleep quality are associated with cognitive performance. Montreal Cognitive Assessment questionnaire is a screening tool to assess mild cognitive (MCI) impairment with a 90% diagnostic sensitivity. In our current study, we used MOCA to identify MCI in patients who underwent sleep study in our sleep department. We then looked at the clinical risk factors and sleep-related parameters in subjects found to have mild cognitive impairment but without a diagnosis of sleep-disordered breathing. Clinical risk factors, including physician, diagnosed hypertension, diabetes, and depression and sleep-related parameters, measured during sleep study, including percentage time of each sleep stage, total sleep time, awakenings, sleep efficiency, apnoea hypopnoea index, and oxygen saturation, were evaluated. A total of 90 subjects who underwent sleep study between March 2019 and October 2019 were included. Currently, there is no pharmacotherapy available for MCI; therefore, identifying the risk factors and attempting to reverse or mitigate their effect is pivotal in slowing down the rate of cognitive deterioration. Further characterization of sleep parameters in this group of patients could open up opportunities for potentially beneficial interventions.

Keywords: apnoea hypopnea index, mild cognitive impairment, sleep architecture, sleep study

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3309 Multi Objective Simultaneous Assembly Line Balancing and Buffer Sizing

Authors: Saif Ullah, Guan Zailin, Xu Xianhao, He Zongdong, Wang Baoxi

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Assembly line balancing problem is aimed to divide the tasks among the stations in assembly lines and optimize some objectives. In assembly lines the workload on stations is different from each other due to different tasks times and the difference in workloads between stations can cause blockage or starvation in some stations in assembly lines. Buffers are used to store the semi-finished parts between the stations and can help to smooth the assembly production. The assembly line balancing and buffer sizing problem can affect the throughput of the assembly lines. Assembly line balancing and buffer sizing problems have been studied separately in literature and due to their collective contribution in throughput rate of assembly lines, balancing and buffer sizing problem are desired to study simultaneously and therefore they are considered concurrently in current research. Current research is aimed to maximize throughput, minimize total size of buffers in assembly line and minimize workload variations in assembly line simultaneously. A multi objective optimization objective is designed which can give better Pareto solutions from the Pareto front and a simple example problem is solved for assembly line balancing and buffer sizing simultaneously. Current research is significant for assembly line balancing research and it can be significant to introduce optimization approaches which can optimize current multi objective problem in future.

Keywords: assembly line balancing, buffer sizing, Pareto solutions

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3308 The Views of German Preparatory Language Programme Students about German Speaking Activity

Authors: Eda Üstünel, Seval Karacabey

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The students, who are enrolled in German Preparatory Language Programme at the School of Foreign Languages, Muğla Sıtkı Koçman University, Turkey, learn German as a foreign language for two semesters in an academic year. Although the language programme is a skills-based one, the students lack German speaking skills due to their fear of making language mistakes while speaking in German. This problem of incompetency in German speaking skills exists also in their four-year departmental study at the Faculty of Education. In order to address this problem we design German speaking activities, which are extra-curricular activities. With the help of these activities, we aim to lead Turkish students of German language to speak in the target language, to improve their speaking skills in the target language and to create a stress-free atmosphere and a meaningful learning environment to communicate in the target language. In order to achieve these aims, an ERASMUS+ exchange staff (a German trainee teacher of German as a foreign language), who is from Schwabisch Gmünd University, Germany, conducted out-of-class German speaking activities once a week for three weeks in total. Each speaking activity is lasted for one and a half hour per week. 7 volunteered students of German preparatory language programme attended the speaking activity for three weeks. The activity took place at a cafe in the university campus, that’s the reason, we call it as an out-of-class activity. The content of speaking activity is not related to the topics studied at the units of coursebook, that’s the reason, we call this activity as extra-curricular one. For data collection, three tools are used. A questionnaire, which is an adapted version of Sabo’s questionnaire, is applied to seven volunteers. An interview session is then held with each student on individual basis. The interview questions are developed so as to ask students to expand their answers that are given at the questionnaires. The German trainee teacher wrote fieldnotes, in which the teacher described the activity in the light of her thoughts about what went well and which areas were needed to be improved. The results of questionnaires show that six out of seven students note that such an acitivity must be conducted by a native speaker of German. Four out of seven students emphasize that they like the way that the activities are designed in a learner-centred fashion. All of the students point out that they feel motivated to talk to the trainee teacher in German. Six out of seven students note that the opportunity to communicate in German with the teacher and the peers enable them to improve their speaking skills, the use of grammatical rules and the use of vocabulary.

Keywords: Learning a Foreign Language, Speaking Skills, Teaching German as a Foreign Language, Turkish Learners of German Language

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3307 Antioxidant, Hypoglycemic and Hypotensive Effects Affected by Various Molecular Weights of Cold Water Extract from Pleurotus Citrinopileatus

Authors: Pao-Huei Chen, Shu-Mei Lin, Yih-Ming Weng, Zer-Ran Yu, Be-Jen Wang

Abstract:

Pancreatic α-amylase and intestinal α-glucosidase are the critical enzymes for the breakdown of complex carbohydrates into di- or mono-saccharide, which play an important role in modulating postprandial blood sugars. Angiotensin converting enzyme (ACE) converts inactive angiotensin-I into active angiotensin-II, which subsequently increase blood pressure through triggering vasoconstriction and aldosterone secretion. Thus, inhibition of carbohydrate-digestion enzymes and ACE will help the management of blood glucose and blood pressure, respectively. Studies showed Pleurotus citrinopileatus (PC), an edible mushroom and commonly cultured in oriental countries, exerted anticancer, immune improving, antioxidative, hypoglycemic and hypolipidemic effects. Previous studies also showed various molecular weights (MW) fractioned from extracts may affect biological activities due to varying contents of bioactive components. Thus, the objective of this study is to investigate the in vitro antioxidant, hypoglycemic and hypotenstive effects and distribution of active compounds of various MWs of cold water extract from P. citrinopileatus (CWEPC). CWEPC was fractioned into four various MW fractions, PC-I (<1 kDa), PC-II (1-3.5 kDa), PC-III (3.5-10 kDa), and PC-IV (>10 kDa), using an ultrafiltration system. The physiological activities, including antioxidant activities, the inhibition capabilities of pancreatic α-amylase, intestinal α-glucosidase, and hypertension-linked ACE, and the active components, including polysaccharides, protein, and phenolic contents, of CWEPC and four fractions were determined. The results showed that fractions with lower MW exerted a higher antioxidant activity (p<0.05), which was positively correlated to the levels of total phenols. In contrast, the inhibition effects on the activities of α-amylase, α-glucosidase, and ACE of PC-IV fraction were significantly higher than CWEPC and the other three low MW fractions (< 10 kDa), which was more related to protein contents. The inhibition capability of CWEPC and PC-IV on α-amylase activity was 1/13.4 to 1/2.7 relative to that of acarbose (positive control), respectively. However, the inhibitory ability of PC-IV on α-glucosidase (IC50 = 0.5 mg/mL) was significantly higher than acarbose (IC50 = 1.7 mg/mL). Kinetic data revealed that PC-IV fraction followed a non-competitive inhibition on α-glucosidase activity. In conclusion, the distribution of various bioactive components contribute to the functions of different MW fractions on oxidative stress prevention, and blood pressure and glucose modulation.

Keywords: α-Amylase, angiotensin converting enzyme, α-Glucosidase, Pleurotus citrinopileatus

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3306 Associations among Fetuin A, Cortisol and Thyroid Hormones in Children with Morbid Obesity and Metabolic Syndrome

Authors: Mustafa Metin Donma, Orkide Donma

Abstract:

Obesity is a disease with an ever-increasing prevalence throughout the world. The metabolic network associated with obesity is very complicated. In metabolic syndrome (MetS), it becomes even more difficult to understand. Within this context, hormones, cytokines, and many others participate in this complex matrix. The collaboration among all of these parameters is a matter of great wonder. Cortisol, as a stress hormone, is closely associated with obesity. Thyroid hormones are involved in the regulation of energy as well as glucose metabolism with all of its associates. Fetuin A is known for years; however, the involvement of this parameter in obesity discussions is rather new. Recently, it has been defined as one of the new generation markers of obesity. In this study, the aim was to introduce complex interactions among all to be able to make clear comparisons, at least for a part of this complicated matter. Morbid obese (MO) children participated in the study. Two groups with 46 MO children and 43 with MetS were constituted. All children included in the study were above 99th age- and sex-adjusted body mass index (BMI) percentiles according to World Health Organization criteria. Forty-three morbid obese children in the second group had also MetS components. Informed consent forms were filled by the parents of the participants. The institutional ethics committee has given approval for the study protocol. Data as well as the findings of the study were evaluated from a statistical point of view. Two groups were matched for their age and gender compositions. Significantly higher body mass index (BMI), waist circumference, thyrotropin, and insulin values were observed in the MetS group. Triiodothyronine concentrations did not differ between the groups. Elevated levels for thyroxin, cortisol, and fetuin-A were detected in the MetS group compared to the first group (p > 0.05). In MO MetS- group, cortisol was correlated with thyroxin and fetuin-A (p < 0.05). In the MO MetS+ group, none of these correlations were present. Instead, a correlation between cortisol and thyrotropin was found (p < 0.05). In conclusion, findings have shown that cortisol was the key player in severely obese children. The association of this hormone with the participants of thyroid hormone metabolism was quite important. The lack of association with fetuin A in the morbid obese MetS+ group has suggested the possible interference of MetS components in the behavior of this new generation obesity marker. The most remarkable finding of the study was the unique correlation between cortisol and thyrotropin in the morbid obese MetS+ group, suggesting that thyrotropin may serve as a target along with cortisol in the morbid obese MetS+ group. This association may deserve specific attention during the development of remedies against MetS in the pediatric population.

Keywords: children, cortisol, fetuin A, morbid obesity, thyrotropin

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3305 The Dynamics of a 3D Vibrating and Rotating Disc Gyroscope

Authors: Getachew T. Sedebo, Stephan V. Joubert, Michael Y. Shatalov

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Conventional configuration of the vibratory disc gyroscope is based on in-plane non-axisymmetric vibrations of the disc with a prescribed circumferential wave number. Due to the Bryan's effect, the vibrating pattern of the disc becomes sensitive to the axial component of inertial rotation of the disc. Rotation of the vibrating pattern relative to the disc is proportional to the inertial angular rate and is measured by sensors. In the present paper, the authors investigate a possibility of making a 3D sensor on the basis of both in-plane and bending vibrations of the disc resonator. We derive equations of motion for the disc vibratory gyroscope, where both in-plane and bending vibrations are considered. Hamiltonian variational principle is used in setting up equations of motion and the corresponding boundary conditions. The theory of thin shells with the linear elasticity principles is used in formulating the problem and also the disc is assumed to be isotropic and obeys Hooke's Law. The governing equation for a specific mode is converted to an ODE to determine the eigenfunction. The resulting ODE has exact solution as a linear combination of Bessel and Neumann functions. We demonstrate how to obtain an explicit solution and hence the eigenvalues and corresponding eigenfunctions for annular disc with fixed inner boundary and free outer boundary. Finally, the characteristics equations are obtained and the corresponding eigenvalues are calculated. The eigenvalues are used for the calculation of tuning conditions of the 3D disc vibratory gyroscope.

Keywords: Bryan’s effect, bending vibrations, disc gyroscope, eigenfunctions, eigenvalues, tuning conditions

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3304 Comparison Between Tension Band Wiring Using K-Wires and Cannulated Screws in Transverse Patella Fracture Fixation

Authors: Daniel Francis, Mo Yassin

Abstract:

Transverse patella fractures are routinely fixed using tension band wiring (TBW) using Kirschner wires and a wire in the shape of a figure of 8. The idea of the study was to compare the outcomes of the traditional technique against the more recently used cannulated screws and fiber tape in the shape of a figure of 8. We performed a retrospective cohort study of all the surgically fixed patella fractures from the year 2019 to 2022. The patients were divided into two groups TBW group and cannulated screws group. The primary outcome measure was the failure of fixation and the need for the removal of metalwork. Twenty-six patellar fractures were studied. TBW was used in 14 (53.8%), and cannulated screws were used for fixation in 12 (46.2%). There was one incident of metalwork failure in the TBW and one incident in the cannulated screws group. Five (35.7%) of patients in the TBW needed symptomatic metal work removed and One (8.3%) in the cannulated screw group. In both groups, the rate of fixation failure was low. Symptomatic implants, the most common complication observed, were higher in the TBW group in our practice. Although the small numbers in both groups, the hope of this study is to shine the light on the use of cannulated screws for patella fractures as it would reduce the need for a second operation and reduce the load on the already stretched services as well as improving the patient experience by not requiring further surgery. Although this is not a brand-new technique, it is not commonly used as there have not yet been any studies that demonstrate the lower rates of second surgery needed.

Keywords: patella, tension band wiring, randomised, new technique

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3303 Modified Model for UV-Laser Corneal Ablation

Authors: Salah Hassab Elnaby, Omnia Hamdy, Aziza Ahmed Hassan, Salwa Abdelkawi, Ibrahim Abdelhalim

Abstract:

Laser corneal reshaping has been proposed as a successful treatment of many refraction disorders. However, some physical and chemical demonstrations of the laser effect upon interaction with the corneal tissue are still not fully explained. Therefore, different computational and mathematical models have been implemented to predict the depth of the ablated channel and calculate the ablation threshold and the local temperature rise. In the current paper, we present a modified model that aims to answer some of the open questions about the ablation threshold, the ablation rate, and the physical and chemical mechanisms of that action. The proposed model consists of three parts. The first part deals with possible photochemical reactions between the incident photons and various components of the cornea (collagen, water, etc.). Such photochemical reactions may end by photo-ablation or just the electronic excitation of molecules. Then a chemical reaction is responsible for the ablation threshold. Finally, another chemical reaction produces fragments that can be cleared out. The model takes into account all processes at the same time with different probabilities. Moreover, the effect of applying different laser wavelengths that have been studied before, namely the common excimer laser (193-nm) and the solid state lasers (213-nm & 266-nm), has been investigated. Despite the success and ubiquity of the ArF laser, the presented results reveal that a carefully designed 213-nm laser gives the same results with lower operational drawbacks. Moreover, the use of mode locked laser could also decrease the risk of heat generation and diffusion.

Keywords: UV lasers, mathematical model, corneal ablation, photochemical ablation

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3302 Rearrangement and Depletion of Human Skin Folate after UVA Exposure

Authors: Luai Z. Hasoun, Steven W. Bailey, Kitti K. Outlaw, June E. Ayling

Abstract:

Human skin color is thought to have evolved to balance sufficient photochemical synthesis of vitamin D versus the need to protect not only DNA but also folate from degradation by ultraviolet light (UV). Although the risk of DNA damage and subsequent skin cancer is related to light skin color, the effect of UV on skin folate of any species is unknown. Here we show that UVA irradiation at 13 mW/cm2 for a total exposure of 187 J/cm2 (similar to a maximal daily equatorial dose) induced a significant loss of total folate in epidermis of ex vivo white skin. No loss was observed in black skin samples, or in the dermis of either color. Interestingly, while the concentration of 5 methyltetrahydrofolate (5-MTHF) fell in white epidermis, a concomitant increase of tetrahydrofolic acid was found, though not enough to maintain the total pool. These results demonstrate that UVA indeed not only decreases folate in skin, but also rearranges the pool components. This could be due in part to the reported increase of NADPH oxidase activity upon UV irradiation, which in turn depletes the NADPH needed for 5-MTHF biosynthesis by 5,10-methylenetetrahydrofolate reductase. The increased tetrahydrofolic acid might further support production of the nucleotide bases needed for DNA repair. However, total folate was lost at a rate that could, with strong or continuous enough exposure to ultraviolet radiation, substantially deplete light colored skin locally, and also put pressure on total body stores for individuals with low intake of folate.

Keywords: depletion, folate, human skin, ultraviolet

Procedia PDF Downloads 384
3301 Early Warning System of Financial Distress Based On Credit Cycle Index

Authors: Bi-Huei Tsai

Abstract:

Previous studies on financial distress prediction choose the conventional failing and non-failing dichotomy; however, the distressed extent differs substantially among different financial distress events. To solve the problem, “non-distressed”, “slightly-distressed” and “reorganization and bankruptcy” are used in our article to approximate the continuum of corporate financial health. This paper explains different financial distress events using the two-stage method. First, this investigation adopts firm-specific financial ratios, corporate governance and market factors to measure the probability of various financial distress events based on multinomial logit models. Specifically, the bootstrapping simulation is performed to examine the difference of estimated misclassifying cost (EMC). Second, this work further applies macroeconomic factors to establish the credit cycle index and determines the distressed cut-off indicator of the two-stage models using such index. Two different models, one-stage and two-stage prediction models, are developed to forecast financial distress, and the results acquired from different models are compared with each other, and with the collected data. The findings show that the two-stage model incorporating financial ratios, corporate governance and market factors has the lowest misclassification error rate. The two-stage model is more accurate than the one-stage model as its distressed cut-off indicators are adjusted according to the macroeconomic-based credit cycle index.

Keywords: Multinomial logit model, corporate governance, company failure, reorganization, bankruptcy

Procedia PDF Downloads 374
3300 Reasons for Food Losses and Waste in Basic Production of Meat Sector in Poland

Authors: Sylwia Laba, Robert Laba, Krystian Szczepanski, Mikolaj Niedek, Anna Kaminska-Dworznicka

Abstract:

Meat and its products are considered food products, having the most unfavorable effect on the environment that requires rational management of these products and waste, originating throughout the whole chain of manufacture, processing, transport, and trade of meat. From the economic and environmental viewpoints, it is important to limit the losses and food wastage and the food waste in the whole meat sector. The link to basic production includes obtaining raw meat, i.e., animal breeding, management, and transport of animals to the slaughterhouse. Food is any substance or product, intended to be consumed by humans. It was determined (for the needs of the present studies) when the raw material is considered as a food. It is the moment when the animals are prepared to loading with the aim to be transported to a slaughterhouse and utilized for food purposes. The aim of the studies was to determine the reasons for loss generation in the basic production of the meat sector in Poland during the years 2017 – 2018. The studies on food losses and waste in the meat sector in basic production were carried out in two areas: red meat i.e., pork and beef and poultry meat. The studies of basic production were conducted in the period of March-May 2019 at the territory of the whole country on a representative trial of 278 farms, including 102 pork production, 55–beef production, and 121 poultry meat production. The surveys were carried out with the utilization of questionnaires by the PAPI (Paper & Pen Personal Interview) method; the pollsters conducted direct questionnaire interviews. Research results indicate that it is followed that any losses were not recorded during the preparation, loading, and transport of the animals to the slaughterhouse in 33% of the visited farms. In the farms where the losses were indicated, the crushing and suffocations, occurring during the production of pigs, beef cattle and poultry, were the main reasons for these losses. They constituted ca. 40% of the reported reasons. The stress generated by loading and transport caused 16 – 17% (depending on the season of the year) of the loss reasons. In the case of poultry production, in 2017, additionally, 10.7% of losses were caused by inappropriate conditions of loading and transportation, while in 2018 – 11.8%. The diseases were one of the reasons for the losses in pork and beef production (7% of the losses). The losses and waste, generated during livestock production and in meat processing and trade cannot be managed or recovered. They have to be disposed of. It is, therefore, important to prevent and minimize the losses throughout the whole production chain. It is possible to introduce the appropriate measures, connected mainly with the appropriate conditions and methods of animal loading and transport.

Keywords: food losses, food waste, livestock production, meat sector

Procedia PDF Downloads 138
3299 Climate Change and Global Warming: Effect on Indian Agriculture and Legal Control

Authors: Aman Guru, Chiron Singhi

Abstract:

The Earth’s climate is being changed at an unrivalled rate since beginning of the evolution of the Earth, 4–5 billion years back, but presently it gained pace due to unintentional anthropogenic disturbances and also increased global warming since the mid-20th century, and these incessant changes in the climatic pattern may bring unpropitious effect on global health and security. Today, however, it is not only the air, or water that are polluted, but the whole atmosphere is prone to pollution and this resulted in other cascading ramification in the form of change in the pattern of rainfall, melting of ice, the rise in the sea level etc. Human activities like production, transport, burning of fuels are adding umpteen dangerous pollutants to the atmosphere which in turn gives rise to global warming. Agriculture plays an imperative part in India's economy. Agriculture, along with fisheries and forestry, is one of the largest contributors to the Gross Domestic Product in India. Research on the effect of climate change and vulnerability of agriculture is a high need in India. A steady increase of CO2 is a primary cause of climate change and global warming and which in turn have a great impact on Indian agriculture. The research focuses on the effect of climate change on Indian agriculture and the proceedings and legal control of legislative measures on such issues and the ways to implement such laws which can help to provide a solution to these problems which can prove beneficial to Indian farmers and their agricultural produce.

Keywords: agriculture, climate change, global warming, India laws, legislative measures

Procedia PDF Downloads 309
3298 Six Sigma-Based Optimization of Shrinkage Accuracy in Injection Molding Processes

Authors: Sky Chou, Joseph C. Chen

Abstract:

This paper focuses on using six sigma methodologies to reach the desired shrinkage of a manufactured high-density polyurethane (HDPE) part produced by the injection molding machine. It presents a case study where the correct shrinkage is required to reduce or eliminate defects and to improve the process capability index Cp and Cpk for an injection molding process. To improve this process and keep the product within specifications, the six sigma methodology, design, measure, analyze, improve, and control (DMAIC) approach, was implemented in this study. The six sigma approach was paired with the Taguchi methodology to identify the optimized processing parameters that keep the shrinkage rate within the specifications by our customer. An L9 orthogonal array was applied in the Taguchi experimental design, with four controllable factors and one non-controllable/noise factor. The four controllable factors identified consist of the cooling time, melt temperature, holding time, and metering stroke. The noise factor is the difference between material brand 1 and material brand 2. After the confirmation run was completed, measurements verify that the new parameter settings are optimal. With the new settings, the process capability index has improved dramatically. The purpose of this study is to show that the six sigma and Taguchi methodology can be efficiently used to determine important factors that will improve the process capability index of the injection molding process.

Keywords: injection molding, shrinkage, six sigma, Taguchi parameter design

Procedia PDF Downloads 173
3297 Legal Initiatives for Afghan Humanitarian Crisis

Authors: Fereshteh Ganjavi, Rachel Schaffer, Varsha Jorawar

Abstract:

Elena’s Light is a non-profit organization focused on building brighter futures for refugees, especially women and children. Our mission is to empower refugee women and children by addressing social, legal, and public health issues that predominantly concern them. Elena’s Light offers a range of services that support refugees from structural disadvantages, cultural and social stress, marginalization, and other stressors related to migration. Using a three-pronged approach, our programs focus on legal advocacy, English language acquisition, and health and wellness. Following the Afghan humanitarian crisis, Elena’s Light has developed and intensified advocacy efforts in the legal realm to address the influx of refugees who desperately need assistance. We developed and hosted a Know Your Rights presentation with local immigration lawyers and professionals in February 2022 on the Afghan Humanitarian Parole, which was very successful with over 100 attendees. Elena’s Light is hosting the second Know Your Rights session in early August 2022 on immigration options for Afghans, including Temporary Protected Status (TPS), asylum, Special Immigrant Visa (SIV), and humanitarian parole. Lastly, EL is also leading the local initiative to develop a pro-bono committee to respond to the overwhelming need for lawyers to work on legal cases for Afghan during this crisis. Furthermore, through our other services, we provide free, in-home customizable ESL tutoring sessions to refugee women with a focus on driver’s education, facilitating acculturation, and improving employment opportunities. We also provide in-home maternal, pediatric, and mental health education and wellness services that are aimed at addressing the explicit and implicit barriers to healthcare for refugee populations. Elena’s Light’s diverse community aims to counter the structural disadvantages and anxiety-inducing emotions and experiences related to being a refugee. We would like to join this International Conference on Refugee Law since protecting refugee rights is our mission. We would like to share what we have learned from our legal initiatives for refugee rights. We would also like to listen, learn from, and discuss with experts and researchers how to better understand and advocate for refugee rights. We hope to improve our understanding of how to provide better legal aid for our clients through this conference.

Keywords: legal, advocacy, Afghan humanitarian crisis, policy, pro-bono

Procedia PDF Downloads 127
3296 CFD Simulation of Spacer Effect on Turbulent Mixing Phenomena in Sub Channels of Boiling Nuclear Assemblies

Authors: Shashi Kant Verma, S. L. Sinha, D. K. Chandraker

Abstract:

Numerical simulations of selected subchannel tracer (Potassium Nitrate) based experiments have been performed to study the capabilities of state-of-the-art of Computational Fluid Dynamics (CFD) codes. The Computational Fluid Dynamics (CFD) methodology can be useful for investigating the spacer effect on turbulent mixing to predict turbulent flow behavior such as Dimensionless mixing scalar distributions, radial velocity and vortices in the nuclear fuel assembly. A Gibson and Launder (GL) Reynolds stress model (RSM) has been selected as the primary turbulence model to be applied for the simulation case as it has been previously found reasonably accurate to predict flows inside rod bundles. As a comparison, the case is also simulated using a standard k-ε turbulence model that is widely used in industry. Despite being an isotropic turbulence model, it has also been used in the modeling of flow in rod bundles and to produce lateral velocities after thorough mixing of coolant fairly. Both these models have been solved numerically to find out fully developed isothermal turbulent flow in a 30º segment of a 54-rod bundle. Numerical simulation has been carried out for the study of natural mixing of a Tracer (Passive scalar) to characterize the growth of turbulent diffusion in an injected sub-channel and, afterwards on, cross-mixing between adjacent sub-channels. The mixing with water has been numerically studied by means of steady state CFD simulations with the commercial code STAR-CCM+. Flow enters into the computational domain through the mass inflow at the three subchannel faces. Turbulence intensity and hydraulic diameter of 1% and 5.9 mm respectively were used for the inlet. A passive scalar (Potassium nitrate) is injected through the mass fraction of 5.536 PPM at subchannel 2 (Upstream of the mixing section). Flow exited the domain through the pressure outlet boundary (0 Pa), and the reference pressure was 1 atm. Simulation results have been extracted at different locations of the mixing zone and downstream zone. The local mass fraction shows uniform mixing. The effect of the applied turbulence model is nearly negligible just before the outlet plane because the distributions look like almost identical and the flow is fully developed. On the other hand, quantitatively the dimensionless mixing scalar distributions change noticeably, which is visible in the different scale of the colour bars.

Keywords: single-phase flow, turbulent mixing, tracer, sub channel analysis

Procedia PDF Downloads 203
3295 Feasibility Study of a Solar Solid Desiccant Cooling System in Algerian Areas

Authors: N. Hatraf, l. Merabeti, M. Abbas

Abstract:

The interest in air conditioning using renewable energies is increasing. The Thermal energy produced from the solar energy can be transformed to useful cooling and heating through the thermo chemical or thermo physical processes by using thermally activated energy conversion system. Solid desiccant conditioning systems can represent a reliable alternative solution compared with other thermal cooling technologies. Their basic characteristics refer to the capability to regulate both temperature and humidity of the conditioned space in one side and to its potential in electrical energy saving in the other side. The ambient air contains so much water that very high dehumidification rates are required. For a continuous dehumidification of the process air the water adsorbed on the desiccant material has to be removed, which is done by allowing hot air to flow through the desiccant material (regeneration). Basically, solid desiccant cooling system transfers moisture from the inlet air to the silica gel by using two processes: absorption process and the regeneration process; The silica gel in the desiccant wheel which is the most important device in the system absorbs the moisture from the incoming air to the desiccant material in this case the silica gel, then it changes the heat with an rotary heat exchanger, after that the air passes through an humidifier to have the humidity required before entering to the local. The main aim of this paper is to study how the dehumidification rate, the generation temperature and many other factors influence the efficiency of a solid desiccant system by using TRNSYS software.

Keywords: desiccation, dehumidification, TRNSYS, efficiency

Procedia PDF Downloads 412
3294 Effects of Multilayer Coating of Chitosan and Polystyrene Sulfonate on Quality of ‘Nam Dok Mai No.4’ Mango

Authors: N. Hadthamard, P. Chaumpluk, M. Buanong, P. Boonyaritthongchai, C. Wongs-Aree

Abstract:

Ripe ‘Nam Dok Mai’ mango (Mangifera indica L.) is an important exported fruit of Thailand, but rapidly declined in the quality attributes mainly by infection of anthracnose and stem end rot diseases. Multilayer coating is considered as a developed technique to maintain the postharvest quality of mangoes. The utilization of alternated coating by matching oppositely electrostatic charges between 0.1% chitosan and 0.1% polystyrene sulfonate (PSS) was studied. A number of the coating layers (layer by layer) were applied on mature green ‘Nam Dok Mai No.4’ mangoes prior to storage at 25 oC, 65-70% relative humidity (RH). There were significant differences in some quality attributes of mangoes coated by 3½ layers, 4½ layers and 5½ layers. In comparison to coated mangoes, uncoated fruits were higher in weight loss, total soluble solids, respiration rate, ethylene production and disease incidence except the titratable acidity. Coating fruit at 3½ layers exhibited the ripening delay and reducing disease infection without off flavour. On the other hand, fruit coated with 5½ layers comprised the lowest acceptable score, caused by exhibiting disorders from fermentation at the end of storage. As a result, multilayer coating between chitosan and PSS could effectively maintain the postharvest quality of mango, but number of coating layers should be thoroughly considered.

Keywords: multilayer, chitosan, polystyrene sulfonate, Nam Dok Mai No.4

Procedia PDF Downloads 207
3293 The Impact of Innovation Best Practices in Economic Development

Authors: Hanadi Mubarak AL-Mubaraki, Michael Busler

Abstract:

Innovation is the process of making changes, differences, and novelties in the products and services, adding values and business practices to create economic and social benefit. The purpose of this paper is to identify the strengths and weaknesses of innovation programs in developed and developing countries. We used a mixed-methods approach, quantitative as survey and qualitative as a multi-case study to examine innovation best practices in developed and developing countries. In addition, four case studies of innovation organisations based on the best practices and successful implementation in the developed and developing countries are selected for examination. The research findings provide guidance, suggestions, and recommendations for future implementation in developed and developing countries for practitioners such as policy makers, governments, funded organizations, and strategic institutions. In conclusion, innovation programs are vital tools for economic growth, knowledge, and technology transfer based on the several indicators such as creativity, entrepreneurship, role of government, role of university, strategic focus, new products, survival rate, job creation, start-up companies, and number of patents. The authors aim to conduct future research which will include a comparative study of innovation case studies between developed and developing countries for policy implications worldwide. The originality of this study makes a contribution to the current literature about the innovation best practice in developed and developing countries.

Keywords: economic development, entrepreneurship, innovation program, developed countries

Procedia PDF Downloads 367
3292 A Multi-Scale Approach for the Analysis of Fiber-Reinforced Composites

Authors: Azeez Shaik, Amit Salvi, B. P. Gautham

Abstract:

Fiber reinforced polymer resin composite materials are finding wide variety of applications in automotive and aerospace industry because of their high specific stiffness and specific strengths when compared to metals. New class of 2D and 3D textile and woven fabric composites offer excellent fracture toughens as they bridge the cracks formed during fracture. Due to complexity of their fiber architectures and its resulting composite microstructures, optimized design and analysis of these structures is very complicated. A traditional homogenization approach is typically used to analyze structures made up of these materials. This approach usually fails to predict damage initiation as well as damage propagation and ultimate failure of structure made up of woven and textile composites. This study demonstrates a methodology to analyze woven and textile composites by using the multi-level multi-scale modelling approach. In this approach, a geometric repetitive unit cell (RUC) is developed with all its constituents to develop a representative volume element (RVE) with all its constituents and their interaction modeled correctly. The structure is modeled based on the RUC/RVE and analyzed at different length scales with desired levels of fidelity incorporating the damage and failure. The results are passed across (up and down) the scales qualitatively as well as quantitatively from the perspective of material, configuration and architecture.

Keywords: cohesive zone, multi-scale modeling, rate dependency, RUC, woven textiles

Procedia PDF Downloads 358
3291 Extraction of M. paradisiaca L. Inflorescences Using Compressed Propane

Authors: Michele C. Mesomo, Madeline de Souza Correa, Roberta L. Kruger, Luis R. S. Kanda, Marcos L. Corazza

Abstract:

Natural extracts of plants have been used for many years for different purposes and recently they have been screened for their potential use as alternative remedies and food preservatives. Inflorescences of M. paradisiaca L., also known as the heart of the banana, have great economic interest due to its fruit. All parts of the banana are used for many different purposes, including use in folk medicine. The use of extraction via supercritical technology has grown in recent years, though it is still necessary to obtain experimental information for the construction of industrial plants. This work reports the extraction of Musa paradisiaca L. using compressed propane as solvent. The effects of the supercritical extraction conditions, pressure and temperature on the yield were evaluated. The raw material, inflorescences banana, was dried at 313.15 K and milled. The particle size used for the packaging of the extraction cell was 12 mesh (23.5%), 16 mesh (23.5%), 32 mesh (34.5%), 48 mesh (18.5%). The extractions were performed in a laboratory scale unit at pressures of 3.0 MPa, 6.5 MPa and 10.0 MPa and at 308.15 K, 323.15 K and 338.15 K. The operating conditions tested achieved a maximum yield of 2.94 wt% for the CO2 extraction at 10.0 MPa and 338.15 K, higher pressure and temperature. The lower yield, 2.29 wt%, was obtained in the condition of lower pressure and higher temperature. Temperature presented significant and positive effect on the extraction yield with supercritical CO2, while pressure had no effect on the yield. The overall extraction curves showed typical behavior obtained for the supercritical extraction procedure and and reached a constant extraction rate of about 80 to 100 min. The largest amount of extract was obtained at the beginning of the process, within 10 to 60 min.

Keywords: banana, natural products, supercritical extraction, temperature

Procedia PDF Downloads 607