Search results for: rate fragments
6430 Assessing the High Rate of Deforestation Caused by the Operations of Timber Industries in Ghana
Authors: Obed Asamoah
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Forests are very vital for human survival and our well-being. During the past years, the world has taken an increasingly significant role in the modification of the global environment. The high rate of deforestation in Ghana is of primary national concern as the forests provide many ecosystem services and functions that support the country’s predominantly agrarian economy and foreign earnings. Ghana forest is currently major source of carbon sink that helps to mitigate climate change. Ghana forests, both the reserves and off-reserves, are under pressure of deforestation. The causes of deforestation are varied but can broadly be categorized into anthropogenic and natural factors. For the anthropogenic factors, increased wood fuel collection, clearing of forests for agriculture, illegal and poorly regulated timber extraction, social and environmental conflicts, increasing urbanization and industrialization are the primary known causes for the loss of forests and woodlands. Mineral exploitation in the forest areas is considered as one of the major causes of deforestation in Ghana. Mining activities especially mining of gold by both the licensed mining companies and illegal mining groups who are locally known as "gallantly mining" also cause damage to the nation's forest reserves. Several works have been conducted regarding the causes of the high rate of deforestation in Ghana, major attention has been placed on illegal logging and using forest lands for illegal farming and mining activities. Less emphasis has been placed on the timber production companies on their harvesting methods in the forests in Ghana and other activities that are carried out in the forest. The main objective of the work is to find out the harvesting methods and the activities of the timber production companies and their effects on the forests in Ghana. Both qualitative and quantitative research methods were engaged in the research work. The study population comprised of 20 Timber industries (Sawmills) forest areas of Ghana. These companies were selected randomly. The cluster sampling technique was engaged in selecting the respondents. Both primary and secondary data were employed. In the study, it was observed that most of the timber production companies do not know the age, the weight, the distance covered from the harvesting to the loading site in the forest. It was also observed that old and heavy machines are used by timber production companies in their operations in the forest, which makes the soil compact prevents regeneration and enhances soil erosion. It was observed that timber production companies do not abide by the rules and regulations governing their operations in the forest. The high rate of corruption on the side of the officials of the Ghana forestry commission makes the officials relax and do not embark on proper monitoring on the operations of the timber production companies which makes the timber companies to cause more harm to the forest. In other to curb this situation the Ghana forestry commission with the ministry of lands and natural resources should monitor the activities of the timber production companies and sanction all the companies that make foul play in their activities in the forest. The commission should also pay more attention to the policy “fell one plant 10” to enhance regeneration in both reserves and off-reserves forest.Keywords: companies, deforestation, forest, Ghana, timber
Procedia PDF Downloads 2016429 Effect of Group Prenatal Care on Adolescent Pregnancy Outcomes: A Randomized Controlled Trial
Authors: Parvin Abedi, Fatemeh Malchi, Mina Iravani, Elham Maraghi, Eesa Mohammadi, Najmieh Saadati
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Background: Adolescent pregnancy has major health and social consequences and can lead to adverse maternal and neonatal outcomes. Objectives: The objective of this study was to evaluate the impact of group prenatal care (GPNC) of adolescents on their maternal and neonatal outcomes. Methods: In this study, 294 adolescent pregnant women (aged 15-19) were randomly assigned into two groups of prenatal care (n=147) and individual prenatal care (IPNC) (n=147). Participants in the intervention group received GPNC at 16-20 weeks of gestational age, while the control group received (IPNC). The data were analyzed using the Chi-square test, independent t-test, and linear and logistic tests. Results: As far as weight gain was concerned, 91.7% and 62.1% of the participants in the GPNC and IPNC groups had an appropriate weight gain during pregnancy, respectively OR 6.72 (95% CI 3.40, 13.26). In the GPNC group, 79.2% of participants had exclusive breastfeeding in the first 6 weeks after childbirth and while this rate was 49.7% in the IPNC group, OR 3.92 (95% CI 2.36, 6.64). Preterm birth was observed in 3.4% of the participants in the GPNC group as opposed to 9.5% in the IPNC group OR 6.17 (95% CI 0.73, 51.93). Conclusion: Adolescent women in GPNC have more appropriate weight gain and a higher rate of exclusive breastfeeding compared to adolescent women in IPNC. Group prenatal care could be considered a viable method of care for adolescent pregnant women.Keywords: group prenatal car, adolescents pregnant women, pregnancy outcomes, neonatal outcomes
Procedia PDF Downloads 226428 Resin-coated Controlled Release Fertilizer (CRF) for Oil Palm: Laboratory and Main Nursery Evaluation
Authors: Umar Adli Amran, Tan Choon Chek, Mohd Shahkhirat Norizan, Then Kek Hoe
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Controlled release fertilizer (CRF) enables a regulated nutrients release for more efficient plant uptake compared to the normal granular fertilizer. It reduces nutrients loss via surface run-off and leaching, hence promotes sustainable agriculture. Although the performance of CRF in providing consistent and timely nutrients supply is well known, its expensive price limits it usage in a large scale plantation. This study is conducted to evaluate the properties and performance of bio-based polyurethane (PU)-coated CRF via laboratory and oil palm main nursery trial. The CRF is produced by coating of a normal commercial compound granular fertilizer from FGV Fertiliser Sdn. Bhd., namely Felda 10 (10.5-8-20-3+0.5B), and designated as CRF FGV10. Based on laboratory evaluation, the CRF FGV10 can sustain nutrients release for more than 6 months. Vegetative growth parameters such as girth size, palm height, third frond length, and the total number of fronds produced were recorded. Besides that, dry biomass of the oil palm seedlings was also determined. From the evaluation, it is proved that at 50% reduction of nutrients application rate and for only two times application (T3), CRF FGV10 enabled the oil palm seedlings to achieve similar vegetative growth with the control samples (T1). It is also proven that only PU-coated CRF FGV10 had allowed the reduction of fertilizer rate and application rounds.Keywords: nutrition, oil palm seedlings, polyurethane, sustainable manuring, vegetative growth
Procedia PDF Downloads 636427 Water Immersion Recovery for Swimmers in Hot Environments
Authors: Thanura Randula Abeywardena
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This study recognized the effectiveness of cold-water immersion recovery post exhaustive short-term exercise. The purpose of this study was to understand if 16- 20°C of cold-water immersion would be beneficial in a tropical environment to achieve optimal recovery in sprint swim performance in comparison to 10-15°C of water immersion. Two 100m-sprint swim performance times were measured along with blood lactate (BLa), heart rate (HR) and rate of perceived exertion (RPE) in a 25m swimming pool with full body head out horizontal water immersions of 10-15°C, 16-20°C and 29-32°C (pool temperature) for 10 minutes followed by 5 minutes of seated passive rest outside; in between the two swim performances. Twelve well-trained adult swimmers (5 male and 5 female) within the top twenty in the Sri Lankan national swimming championships in 100m Butterfly and Freestyle in the years 2020 & 2021 volunteered for this study. One-way ANOVA analysis (p<0.05) suggested performance time, Bla and HR had no significant differences between the 3 conditions after the second sprint; however, RPE was significantly different with p=0.034 between 10-15°C and 16-20°C immersion conditions. The study suggested that the recovery post the two cold-water immersion conditions were similar in terms of performance and physiological factors; however, the 16-20°C temperature had a better “feel good” factor post sprint 2. Further study is recommended as there was participant bias with the swimmers not reaching optimal levels in sprint 1. Therefore, they might have possibly fully recovered before sprint 2, invalidating the physiological effect of recovery.Keywords: hydrotherapy, blood lactate, fatigue, recovery, sprint-performance, sprint-swimming
Procedia PDF Downloads 1026426 Use of Silicate or Chicken Compost in Calacarious Soil on Productivity and Mineral Status of Wheat Plants under Different Levels of Phosphorus
Authors: Hanan, S. Siam, Safaa A. Mahmoud, A. S. Taalab
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A pot experiment was conducted in greenhouse of NRC, Dokki, Cairo, Egypt to study the response of wheat plants to different levels of superphosphate at (60kg P2O5 or 30 kg P2O5) with or without potassium silicate or chicken compost (2.5 ton/fed.) on growth yield and nutrients status especially, and phosphorus and silica availability. Data reveal that the addition either chicken or compost increased significantly affected on all the growth and yield parameters as well as nutrients status and protein of the different parts of wheat plants if compared with control (60kg P2O5 or 30 kg P2O5). Data also reveal that the highest mean values were obtained when potassium silicate with was added to 60 kg P2O5, while the lowest values of the previous parameters were obtained when 30 kg P2O5 alone was added to plants. Furthermore, data indicated that the highest mean values of all mentioned parameters were obtained when chicken compost was applied with any rate of P as compared with silica addition at the same rates of P. According to the results, the highest values of all mentioned parameters were obtained when addition of chicken compost and potassium silicate including the high rate of P at (60 kg P2O5) while the lowest values of the previous parameters were obtained when plants received of phosphorus (30 kg P2O5) alone.Keywords: wheat, yield, chicken compost, potassium, phosphorus, silicate, nutrients status
Procedia PDF Downloads 2766425 Institutional Effectiveness in Fostering Student Retention and Success in First Year
Authors: Naziema B. Jappie
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The objective of this study is to examine the relationship between college readiness characteristics and learning outcome assessment scores. About this, it is important to examine the first-year retention and success rate. In order to undertake this study, it will be necessary to look at proficiency levels on general and domain-specific knowledge and skills reflected on national benchmark test scores (NBT), in-college interventions and course-taking patterns. Preliminary results based on data from more than 1000 students suggest that there is a positive association between NBT scores and students’ 1st-year college GPA and their retention status. For example, 63% of students with a proficient level of math skills in the NBT had the highest level of GPA at the end of 1st-year of college in comparison to 56% of those who started with a primary or intermediate level, respectively. The retention rates among those with proficiency levels were also higher than those with basic or intermediate levels (98% vs. 93% and 88%, respectively). By the end of 3rd year in college, students with intermediate or proficient entering NBT math skills had 7% and 8% of dropout rate, compared to 14% for those started at primary level; a greater percentage of students qualified by the end of 3rd-year qualified among proficient students than that among intermediate or basic level students (50% vs. 44% and 27% respectively). The findings of this study added knowledge to the field in South Africa and are expected to help stakeholders and policymakers to better understand college learning and challenges for students with disadvantaged backgrounds and provide empirical evidence in support of related practices and policies.Keywords: assessment, data analysis, performance, proficiency, policy, student success
Procedia PDF Downloads 1346424 Energy Conservation in Heat Exchangers
Authors: Nadia Allouache
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Energy conservation is one of the major concerns in the modern high tech era due to the limited amount of energy resources and the increasing cost of energy. Predicting an efficient use of energy in thermal systems like heat exchangers can only be achieved if the second law of thermodynamics is accounted for. The performance of heat exchangers can be substantially improved by many passive heat transfer augmentation techniques. These letters permit to improve heat transfer rate and to increase exchange surface, but on the other side, they also increase the friction factor associated with the flow. This raises the question of how to employ these passive techniques in order to minimize the useful energy. The objective of this present study is to use a porous substrate attached to the walls as a passive enhancement technique in heat exchangers and to find the compromise between the hydrodynamic and thermal performances under turbulent flow conditions, by using a second law approach. A modified k- ε model is used to simulating the turbulent flow in the porous medium and the turbulent shear flow is accounted for in the entropy generation equation. A numerical modeling, based on the finite volume method is employed for discretizing the governing equations. Effects of several parameters are investigated such as the porous substrate properties and the flow conditions. Results show that under certain conditions of the porous layer thickness, its permeability, and its effective thermal conductivity the minimum rate of entropy production is obtained.Keywords: second law approach, annular heat exchanger, turbulent flow, porous medium, modified model, numerical analysis
Procedia PDF Downloads 2886423 Modelling and Investigation of Phase Change Phenomena of Multiple Water Droplets
Authors: K. R. Sultana, K. Pope, Y. S. Muzychka
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In recent years, the research of heat transfer or phase change phenomena of liquid water droplets experiences a growing interest in aircraft icing, power transmission line icing, marine icing and wind turbine icing applications. This growing interest speeding up the research from single to multiple droplet phenomena. Impingements of multiple droplets and the resulting solidification phenomena after impact on a very cold surface is computationally studied in this paper. The model used in the current study solves the flow equation, composed of energy balance and the volume fraction equations. The main aim of the study is to investigate the effects of several thermo-physical properties (density, thermal conductivity and specific heat) on droplets freezing. The outcome is examined by various important factors, for instance, liquid fraction, total freezing time, droplet temperature and total heat transfer rate in the interface region. The liquid fraction helps to understand the complete phase change phenomena during solidification. Temperature distribution and heat transfer rate help to demonstrate the overall thermal exchange behaviors between the droplets and substrate surface. Findings of this research provide an important technical achievement for ice modeling and prediction studies.Keywords: droplets, CFD, thermos-physical properties, solidification
Procedia PDF Downloads 2456422 Hot Corrosion and Oxidation Degradation Mechanism of Turbine Materials in a Water Vapor Environment at a Higher Temperature
Authors: Mairaj Ahmad, L. Paglia, F. Marra, V. Genova, G. Pulci
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This study employed Rene N4 and FSX 414 superalloys, which are used in numerous turbine engine components due of their high strength, outstanding fatigue, creep, thermal, and corrosion-resistant properties. An in-depth examination of corrosion mechanisms with vapor present at high temperature is necessary given the industrial trend toward introducing increasing amounts of hydrogen into combustion chambers in order to boost power generation and minimize pollution in contrast to conventional fuels. These superalloys were oxidized in recent tests for 500, 1000, 2000, 3000 and 4000 hours at 982±5°C temperatures with a steady airflow at a flow rate of 10L/min and 1.5 bar pressure. These superalloys were also examined for wet corrosion for 500, 1000, 2000, 3000, and 4000 hours in a combination of air and water vapor flowing at a 10L/min rate. Weight gain, X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy dispersive x-ray spectroscopy (EDS) were used to assess the oxidation and heat corrosion resistance capabilities of these alloys before and after 500, 1000, and 2000 hours. The oxidation/corrosion processes that accompany the formation of these oxide scales are shown in the graph of mass gain vs time. In both dry and wet oxidation, oxides like Al2O3, TiO2, NiCo2O4, Ni3Al, Ni3Ti, Cr2O3, MnCr2O4, CoCr2O4, and certain volatile compounds notably CrO2(OH)2, Cr(OH)3, Fe(OH)2, and Si(OH)4 are formed.Keywords: hot corrosion, oxidation, turbine materials, high temperature corrosion, super alloys
Procedia PDF Downloads 896421 Prevalence Rate and Types of the Domestic Violence Against Deaf in Iran
Authors: Hadi Farahani, Mahsa Tahzibi, Laleh Golamrej Eliasi, Mohammad Torkashvand
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Iranian deafs are an under-researched population. The lack of research comes from the fact that if none, there are very few researchers capable of speaking sign language. The exclusion of this minority group from mainstream society often distorts the general understanding of prevalent issues of the deaf in Iran. The topic of this research was co-created through preliminary discussions with the Iranian deaf. Domestic violence then was picked up as an infrastructural issue impacting other dimensions of deaf lives such as work, education, and outside family relationships. For this purpose, we systematically searched the literature seeking a comprehensive questionnaire. We came across a 46-item standardized questionnaire measuring domestic violence in Iran. To adapt this questionnaire, we followed standard procedures reflected in another article. The inclusion criteria of the current research were married (had experienced living with a partner before) and +18-year-old deaf. Sampling was random and recruitment of the participants was through governmental or voluntary organizations for the deaf. 390 questionnaires then were analyzed through SPSS version 27. Analysis showed that the prevalence rate of domestic violence was 26% in general that emotional violence with 29% was the most prevalent type. Findings suggested that the more educated, and economically independent were the participants, the lower the probability of encountering domestic violence. Domestic violence within families where all members were deaf proved to be less usual than in families in which only the participant was deaf. Further interventional research is needed to assess how to empower the Iranian deaf regarding domestic violence.Keywords: deaf, domestic violence, economic violence, emotional violence, physical violence, sexual violence
Procedia PDF Downloads 1346420 Effect of Ginger (Zingiber Officinale) And Garlic (Allium Sativum) Mixture on Growth Performance, Feed Utilization and Survival of Clarias Gariepinus Fingerlings
Authors: Maryam I. Abdullahi, Suleiman Aliyu, Armaya'u Hamisu Bichi
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The study was conducted at the University Fish Farm, Federal University Dutsinma. The aim of the study was to determine the effects of dietary supplementation of Allium sativum and Zingiber officinale mixture on growth performance, feed utilization and survival of C. gariepinus fingerling reared in tank system. The experimental setup comprised of four treatment (4) groups labeled as T1, T2, T3 and T4, each treatment replicated 3 times with ten (10) fingerlings in each replicate respectively. Treatment 1 contained 0.5% of Zingiber officinale and 0.5% of Allium sativum (ZO-AS: 1.0%), Treatment 2 contained 0.75% Zingiber officinale, and 0.75% garlic (ZO-AS: 1.5%) while T3 contained 1% ginger and 1% Allium sativum (ZO-AS: 2.0%) respectively. The experiment lasted for twelve (12) weeks (84 days). The survival rate ranges from 90% - 100%. With a higher Final Mean Weight (893.10) and Percentage Mean Weight (942.65) as compared to the control group and others. There was no significant difference (p > 0.05) in the FMW (893.10) of the fish fed 1.5g/kg of Garlic and Ginger diets than the control (687.00). The SGR (1.20) of fish-fed Zingiber officinale and Allium sativum fortified diets shows that there is no significant difference between treatments fed 1.5g/kg Zingiber officinale and Allium sativum and the control group. Generally, there was an increased survival rate in the experimental fish-fed Zingiber officinale and Allium sativum-supplemented diets as compared to the control.Keywords: clarias gariepinus, zingiber officinale, allium sativum, fingerlings
Procedia PDF Downloads 696419 Classification of ECG Signal Based on Mixture of Linear and Non-Linear Features
Authors: Mohammad Karimi Moridani, Mohammad Abdi Zadeh, Zahra Shahiazar Mazraeh
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In recent years, the use of intelligent systems in biomedical engineering has increased dramatically, especially in the diagnosis of various diseases. Also, due to the relatively simple recording of the electrocardiogram signal (ECG), this signal is a good tool to show the function of the heart and diseases associated with it. The aim of this paper is to design an intelligent system for automatically detecting a normal electrocardiogram signal from abnormal one. Using this diagnostic system, it is possible to identify a person's heart condition in a very short time and with high accuracy. The data used in this article are from the Physionet database, available in 2016 for use by researchers to provide the best method for detecting normal signals from abnormalities. Data is of both genders and the data recording time varies between several seconds to several minutes. All data is also labeled normal or abnormal. Due to the low positional accuracy and ECG signal time limit and the similarity of the signal in some diseases with the normal signal, the heart rate variability (HRV) signal was used. Measuring and analyzing the heart rate variability with time to evaluate the activity of the heart and differentiating different types of heart failure from one another is of interest to the experts. In the preprocessing stage, after noise cancelation by the adaptive Kalman filter and extracting the R wave by the Pan and Tampkinz algorithm, R-R intervals were extracted and the HRV signal was generated. In the process of processing this paper, a new idea was presented that, in addition to using the statistical characteristics of the signal to create a return map and extraction of nonlinear characteristics of the HRV signal due to the nonlinear nature of the signal. Finally, the artificial neural networks widely used in the field of ECG signal processing as well as distinctive features were used to classify the normal signals from abnormal ones. To evaluate the efficiency of proposed classifiers in this paper, the area under curve ROC was used. The results of the simulation in the MATLAB environment showed that the AUC of the MLP and SVM neural network was 0.893 and 0.947, respectively. As well as, the results of the proposed algorithm in this paper indicated that the more use of nonlinear characteristics in normal signal classification of the patient showed better performance. Today, research is aimed at quantitatively analyzing the linear and non-linear or descriptive and random nature of the heart rate variability signal, because it has been shown that the amount of these properties can be used to indicate the health status of the individual's heart. The study of nonlinear behavior and dynamics of the heart's neural control system in the short and long-term provides new information on how the cardiovascular system functions, and has led to the development of research in this field. Given that the ECG signal contains important information and is one of the common tools used by physicians to diagnose heart disease, but due to the limited accuracy of time and the fact that some information about this signal is hidden from the viewpoint of physicians, the design of the intelligent system proposed in this paper can help physicians with greater speed and accuracy in the diagnosis of normal and patient individuals and can be used as a complementary system in the treatment centers.Keywords: neart rate variability, signal processing, linear and non-linear features, classification methods, ROC Curve
Procedia PDF Downloads 2646418 Garlic (Allium sativum) Extract Enhancing Protein Digestive Enzymes and Growth Performance in Marble Goby (Oxyleotris marmorata) Juvenile
Authors: Jaturong Matidtor, Krisna R. Torrissen, Saengtong Pongjareankit, Sudaporn Tongsiri, Jiraporn Rojtinnakorn
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Low survival rate has being particular problem in nursery of marble goby juvenile. The aim of this study was to investigate effect of garlic extract on protein digestive pancreatic enzymes, trypsin (T) and chymotrypsin (C). The marble goby were reared with commercial feed mixed garlic extract at concentration of 0 (control), 0.3, 0.5, 1.0, 3.0 and 5.0% (w/w) for 6 weeks. Analysis of the digestive enzymes at 2 and 6 weeks was performed. Growth parameters; weight gain (WG), specific growth rate (SGR) and feed efficiency (FE), were identified. For T, C and T/C at 2 weeks, values of T and T/C ratio of 0.3% (w/w) group showed significant difference (p < 0.05) with the highest values of 17685.64± 11981.77 U/mg protein and of 51.64 ± 27.46 U/mg protein, respectively. For C at 2 weeks, 0% (w/w) group showed the highest values of 16191.76± 2225.56 U/mg protein. Whereas value of T, C and T/C ratio at 6 weeks, there was no significant difference (p > 0.05). For growth performance, it significantly increased in all garlic extract fed groups (0.3-5.0%, w/w), both at 2 and 6 weeks. At 2 weeks, values of WG and SGR of 0.5% (w/w) group showed the highest values of 71.51 ± 1.60%, and 3.85 ± 0.07%, respectively. For FE, 0.3% (w/w) group showed the highest value of 60.21 ± 6.51%. At 6 weeks, it illustrated that all growth parameters of 5.0% (w/w) group were the highest values; WG = 35.06 ± 5.66%, SGR = 2.14 ± 0.30%, and FE = 5.86 ± 0.68%. We suggested that garlic extract could be available for protein digestive enzyme and growth enhancement in marble goby nursery with artificial feed. This result will be high benefit for commercial aquaculture of marble goby.Keywords: marble goby, nursery, garlic extract, digestive enzyme, growth
Procedia PDF Downloads 3266417 Multi-Objective Optimization in Carbon Abatement Technology Cycles (CAT) and Related Areas: Survey, Developments and Prospects
Authors: Hameed Rukayat Opeyemi, Pericles Pilidis, Pagone Emanuele
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An infinitesimal increase in performance can have immense reduction in operating and capital expenses in a power generation system. Therefore, constant studies are being carried out to improve both conventional and novel power cycles. Globally, power producers are constantly researching on ways to minimize emission and to collectively downsize the total cost rate of power plants. A substantial spurt of developmental technologies of low carbon cycles have been suggested and studied, however they all have their limitations and financial implication. In the area of carbon abatement in power plants, three major objectives conflict: The cost rate of the plant, Power output and Environmental impact. Since, an increase in one of this parameter directly affects the other. This poses a multi-objective problem. It is paramount to be able to discern the point where improving one objective affects the other. Hence, the need for a Pareto-based optimization algorithm. Pareto-based optimization algorithm helps to find those points where improving one objective influences another objective negatively and stops there. The application of Pareto-based optimization algorithm helps the user/operator/designer make an informed decision. This paper sheds more light on areas that multi-objective optimization has been applied in carbon abatement technologies in the last five years, developments and prospects.Keywords: gas turbine, low carbon technology, pareto optimal, multi-objective optimization
Procedia PDF Downloads 7926416 Melanoma and Non-Melanoma, Skin Lesion Classification, Using a Deep Learning Model
Authors: Shaira L. Kee, Michael Aaron G. Sy, Myles Joshua T. Tan, Hezerul Abdul Karim, Nouar AlDahoul
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Skin diseases are considered the fourth most common disease, with melanoma and non-melanoma skin cancer as the most common type of cancer in Caucasians. The alarming increase in Skin Cancer cases shows an urgent need for further research to improve diagnostic methods, as early diagnosis can significantly improve the 5-year survival rate. Machine Learning algorithms for image pattern analysis in diagnosing skin lesions can dramatically increase the accuracy rate of detection and decrease possible human errors. Several studies have shown the diagnostic performance of computer algorithms outperformed dermatologists. However, existing methods still need improvements to reduce diagnostic errors and generate efficient and accurate results. Our paper proposes an ensemble method to classify dermoscopic images into benign and malignant skin lesions. The experiments were conducted using the International Skin Imaging Collaboration (ISIC) image samples. The dataset contains 3,297 dermoscopic images with benign and malignant categories. The results show improvement in performance with an accuracy of 88% and an F1 score of 87%, outperforming other existing models such as support vector machine (SVM), Residual network (ResNet50), EfficientNetB0, EfficientNetB4, and VGG16.Keywords: deep learning - VGG16 - efficientNet - CNN – ensemble – dermoscopic images - melanoma
Procedia PDF Downloads 836415 Incidence of Orphans Neonatal Puppies Attend in Veterinary Hospital – Causes, Consequences and Mortality
Authors: Maria L. G. Lourenço, Keylla H. N. P. Pereira, Viviane Y. Hibaru, Fabiana F. Souza, João C. P. Ferreira, Simone B. Chiacchio, Luiz H. A. Machado
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Orphaned is a risk factor for mortality in newborns since it is a condition with total or partial absence of maternal care that is essential for neonatal survival, including nursing (nutrition, the transference of passive immunity and hydration), warmth, urination, and defecation stimuli, and protection. The most common causes of mortality in orphans are related to lack of assistance, handling mistakes and infections. This study aims to describe the orphans rates in neonatal puppies, the main causes, and the mortality rates. The study included 735 neonates admitted to the Sao Paulo State University (UNESP) Veterinary Hospital, Botucatu, Sao Paulo, Brazil, between January 2018 and November 2019. The orphans rate was 43.4% (319/735) of all neonates included, and the main causes for orphaned were related to maternal agalactia/hypogalactia (23.5%, 75/319); numerous litter (15.7%, 50/319), toxic milk syndrome due to maternal mastitis (14.4%, 46/319), absence of suction/weak neonate (12.2%, 39/319), maternal disease (9.4%, 30/319), cleft palate/lip (6.3%, 20/319), maternal death (5.9%, 19/319), prematurity (5.3%, 17/319), rejection/failure in maternal instinct (3.8%, 12/319) and abandonment by the owner/separation of mother and neonate (3.5%, 11/319). The main consequences of orphaned observed in the admitted neonates were hypoglycemia, hypothermia, dehydration, aspiration pneumonia, wasting syndrome, failure in the transference of passive immunity, infections and sepsis, which happened due to failure of identifying the problem early, lack of adequate assistance, negligence and handling mistakes by the owner. The total neonatal mortality rate was 8% (59/735) and the neonatal mortality rate among orphans was 18.5% (59/319). The orphaned and mortality rates were considered high, but even higher rates may be observed in locations without adequate neonatal assistance and owner orientation. The survival of these patients is related to constant monitoring of the litter, early diagnosis and assistance, and the implementation of effective handling for orphans. Understanding the correct handling for neonates and instructing the owners regarding proper handling are essential to minimize the consequences of orphaned and the mortality rates.Keywords: orphans, neonatal care, puppies, newborn dogs
Procedia PDF Downloads 2586414 Need Assessments of Midwives in Public's Health Center (Puskesmas) at Sukabumi Municipal, Province of Jawa Barat, Indonesia
Authors: Al Asyary, Meita Veruswati, Dian Ayyubi
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Sukabumi municipal has highest rank for maternal mortality in Indonesia with 102 by 100,000 live birth with almost 80% of birth were not attended by skilled birth attendant (SBA). Although universal health coverage has been implemented, availability and sufficiency of SBA, such as midwife in this developing country, are problematic agenda for the quality of public healthcare as well as decreasing maternal mortality rate. This study aims to describe the equal distribution of midwives in Sukabumi municipal as support of government’s program named Millennium Development Goals (MDGs) that suppressed maternal mortality rate in Indonesia. We conducted an observational study with Workload Indicator of Staffing Need (WISN) analysis to present the dispersion of midwives by their activities and workloads in 37 Puskesmas. We also generated in-depth interview with several executive chief of health sections, including chief of health offices in Sukabumi municipal. It resulted inferentially that several activities in midwives’ program were differed at once of existing than needed condition ideally (ρ value = 0.002 < 0.05). Meanwhile, decision for midwives’ procurement and placement were held by un-systematically procedure such as based on where the midwife was staying, and it also progressed by neighborhood issue priorities. The absence of formal regulation in local government is a serious problem that indicated poor political commitment, while access to SBA shall be focused carefully.Keywords: developing country, health professional resources, health policy, need assessment
Procedia PDF Downloads 1696413 Research on Pilot Sequence Design Method of Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing System Based on High Power Joint Criterion
Authors: Linyu Wang, Jiahui Ma, Jianhong Xiang, Hanyu Jiang
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For the pilot design of the sparse channel estimation model in Multiple Input Multiple Output Orthogonal Frequency Division Multiplexing (MIMO-OFDM) systems, the observation matrix constructed according to the matrix cross-correlation criterion, total correlation criterion and other optimization criteria are not optimal, resulting in inaccurate channel estimation and high bit error rate at the receiver. This paper proposes a pilot design method combining high-power sum and high-power variance criteria, which can more accurately estimate the channel. First, the pilot insertion position is designed according to the high-power variance criterion under the condition of equal power. Then, according to the high power sum criterion, the pilot power allocation is converted into a cone programming problem, and the power allocation is carried out. Finally, the optimal pilot is determined by calculating the weighted sum of the high power sum and the high power variance. Compared with the traditional pilot frequency, under the same conditions, the constructed MIMO-OFDM system uses the optimal pilot frequency for channel estimation, and the communication bit error rate performance obtains a gain of 6~7dB.Keywords: MIMO-OFDM, pilot optimization, compressed sensing, channel estimation
Procedia PDF Downloads 1496412 Improvement Anaerobic Digestion Performance of Sewage Sludge by Co-Digestion with Cattle Manure
Authors: Raouf Hassan
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Biogas energy production from sewage sludge is an economically feasible and eco-friendly in nature. Sewage sludge is considered nutrient-rich substrates, but had lower values of carbone which consider an energy source for anaerobic bacteria. The lack or lower values of carbone-to-nitrogen ratio (C/N) reduced biogas yield and fermentation rate. Anaerobic co-digestion of sewage sludge offers several benefits over mono-digestion such as optimize nutrient balance, increased cost-efficiency and increased degradation rate. The high produced amounts of animal manures, which reach up to 90% of the total collected organic wastes, are recommended for the co-digestion with sewage sludge, especially with the limitations of industrial substrates. Moreover, cattle manures had high methane production potential (500 m3/t vsadded). When mixed with sewage sludge the potential methane production increased with increasing cattle manure content. In this paper, the effect of cattle manure (CM) addition as co-substrates on the sewage sludge (SS) anaerobic digestion performance was investigated under mesophilic conditions (35°C) using anaerobic batch reactors. The batch reactors were operated with a working volume 0.8 liter, and a hydraulic retention time of 30 days. The research work focus on studying two main parameters; the biogas yield (expressed as VSS) and pH values inside the reactors.Keywords: anaerobic digestion, sewage sludge, cattle manure, mesophilic, biogas yield, pH
Procedia PDF Downloads 3166411 Co-Smoldered Digestate Ash as Additive for Anaerobic Digestion of Berry Fruit Waste: Stability and Enhanced Production Rate
Authors: Arinze Ezieke, Antonio Serrano, William Clarke, Denys Villa-Gomez
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Berry cultivation results in discharge of high organic strength putrescible solid waste which potentially contributes to environmental degradation, making it imperative to assess options for its complete management. Anaerobic digestion (AD) could be an ideal option when the target is energy generation; however, due to berry fruit characteristics high carbohydrate composition, the technology could be limited by its high alkalinity requirement which suggests dosing of additives such as buffers and trace elements supplement. Overcoming this limitation in an economically viable way could entail replacement of synthetic additives with recycled by-product waste. Consequently, ash from co-smouldering of high COD characteristic AD digestate and coco-coir could be a promising material to be used to enhance the AD of berry fruit waste, given its characteristic high pH, alkalinity and metal concentrations which is typical of synthetic additives. Therefore, the aim of the research was to evaluate the stability and process performance from the AD of BFW when ash from co-smoldered digestate and coir are supplemented as alkalinity and trace elements (TEs) source. Series of batch experiments were performed to ascertain the necessity for alkalinity addition and to see whether the alkalinity and metals in the co-smouldered digestate ash can provide the necessary buffer and TEs for AD of berry fruit waste. Triplicate assays were performed in batch systems following I/S of 2 (in VS), using serum bottles (160 mL) sealed and placed in a heated room (35±0.5 °C), after creating anaerobic conditions. Control experiment contained inoculum and substrates only, and inoculum, substrate and NaHCO3 for optimal total alkalinity concentration and TEs assays, respectively. Total alkalinity concentration refers to alkalinity of inoculum and the additives. The alkalinity and TE potential of the ash were evaluated by supplementing ash (22.574 g/kg) of equivalent total alkalinity concentration to that of the pre-determined optimal from NaHCO3, and by dosing ash (0.012 – 7.574 g/kg) of varying concentrations of specific essential TEs (Co, Fe, Ni, Se), respectively. The result showed a stable process at all examined conditions. Supplementation of 745 mg/L CaCO3 NaHCO3 resulted to an optimum TAC of 2000 mg/L CaCO3. Equivalent ash supplementation of 22.574 g/kg allowed the achievement of this pre-determined optimum total alkalinity concentration, resulting to a stable process with a 92% increase in the methane production rate (323 versus 168 mL CH4/ (gVS.d)), but a 36% reduction in the cumulative methane production (103 versus 161 mL CH4/gVS). Addition of ashes at incremental dosage as TEs source resulted to a reduction in the Cumulative methane production, with the highest dosage of 7.574 g/kg having the highest effect of -23.5%; however, the seemingly immediate bioavailability of TE at this high dosage allowed for a +15% increase in the methane production rate. With an increased methane production rate, the results demonstrated that the ash at high dosages could be an effective supplementary material for either a buffered or none buffered berry fruit waste AD system.Keywords: anaerobic digestion, alkalinity, co-smoldered digestate ash, trace elements
Procedia PDF Downloads 1246410 Role of Vitamin D in Osseointegration of Dental Implant
Authors: Pouya Khaleghi
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Dental implants are a successful treatment modality for restoring both function and aesthetics. Dental implant treatment has predictive results in the replacement of the lost teeth and has a high success rate even in the long term. The most important factor which is responsible for the positive course of implant treatment is the process of osseointegration between the implant structure and the host’s bone tissue. During recent years, many studies have focused on surgical and prosthetic factors, as well as the implant-related factors. However, implant failure still occurs despite the improvements that have led to the increased survival rate of dental implants, which suggests the possible role of some host-related risk factors. Vitamin D is a fat-soluble vitamin regulating calcium and phosphorus metabolism in tissues. The role of vitamin D in bone healing has been under investigation for several years. Vitamin D deficiency has also been associated with impaired and delayed callus formation and fractures healing; however, the role of vitamin D has not been clarified. Therefore, it is extremely important to study the phenomenon of a connection formed between bone tissue and the surface of a titanium implant and find correlations between the 25- hydroxycholecalciferol concentration in blood serum and the course of osseointegration. Because the processes of bone remodeling are very dynamic in the period of actual osseointegration, it is necessary to obtain the correct concentration of vitamin D3 metabolites in blood serum. In conclusion, the correct level of 25-hydroxycholecalciferol on the day of surgery and vitamin D deficiency treatment have a significant influence on the increase in the bone level at the implant site during the process of osseointegration assessed radiologically.Keywords: implant, osseointegration, vitamin d, dental
Procedia PDF Downloads 1756409 Efficiency of Natural Metabolites on Quality Milk Production in Mixed Breed Cows.
Authors: Mariam Azam, Sajjad Ur Rahman, Mukarram Bashir, Muhammad Tahir, Seemal Javaid, Jawad, Aoun Muhammad, Muhammad Zohaib, Hannan Khan
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Products of microbial origin are of great importance as they have proved their value in healthcare and nutrition, use of these microbial metabolites acquired from partially fermented soya hulls and wheat bran along with Saccharomyces cerevisiae (DL-22 S/N) substantiates to be a great source for an increase in the total milk production and quality yield.1×109 CFU/ml cells of Saccharomyces cerevisiae (DL-22 S/N) were further grown under in-vivo conditions for the assessment of quality milk production. Two groups with twelve cows, each having the same physical characteristics (Group A and Group B), were under study, Group A was daily fed with 12gm of biological metabolites and 22% protein-pelleted feed. On the other hand, the animals of Group B were provided with no metabolites in their feed. In thirty days of trial, improvement in the overall health, body score, milk protein, milk fat, yield, incidence rate of mastitis, ash, and solid not fat (SNF) was observed. The collected data showed that the average quality milk production was elevated up to 0.45 liter/h/d. However, a reduction in the milk fats up to 0.45% and uplift in the SNF value up to 0.53% of cow milk was also observed. At the same time, the incidence rate of mastitis recorded for the animals under trial was reduced to half, and improved non specific immunity was reported.Keywords: microbial metabolites, post-biotics, animal supplements, animal nutrition, proteins, animal production, fermentation
Procedia PDF Downloads 1026408 Heat and Mass Transfer Modelling of Industrial Sludge Drying at Different Pressures and Temperatures
Authors: L. Al Ahmad, C. Latrille, D. Hainos, D. Blanc, M. Clausse
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A two-dimensional finite volume axisymmetric model is developed to predict the simultaneous heat and mass transfers during the drying of industrial sludge. The simulations were run using COMSOL-Multiphysics 3.5a. The input parameters of the numerical model were acquired from a preliminary experimental work. Results permit to establish correlations describing the evolution of the various parameters as a function of the drying temperature and the sludge water content. The selection and coupling of the equation are validated based on the drying kinetics acquired experimentally at a temperature range of 45-65 °C and absolute pressure range of 200-1000 mbar. The model, incorporating the heat and mass transfer mechanisms at different operating conditions, shows simulated values of temperature and water content. Simulated results are found concordant with the experimental values, only at the first and last drying stages where sludge shrinkage is insignificant. Simulated and experimental results show that sludge drying is favored at high temperatures and low pressure. As experimentally observed, the drying time is reduced by 68% for drying at 65 °C compared to 45 °C under 1 atm. At 65 °C, a 200-mbar absolute pressure vacuum leads to an additional reduction in drying time estimated by 61%. However, the drying rate is underestimated in the intermediate stage. This rate underestimation could be improved in the model by considering the shrinkage phenomena that occurs during sludge drying.Keywords: industrial sludge drying, heat transfer, mass transfer, mathematical modelling
Procedia PDF Downloads 1356407 Acid Soil Amelioration Using Coal Bio-Briquette Ash and Waste Concrete in China
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The decrease in agricultural production due to soil deterioration has been an urgent task. Soil acidification is a potentially serious land degradation issue and it will have a major impact on agricultural productivity and sustainable farming systems. In China, acid soil is mainly distributed in the southern part, the decrease in agricultural production and heavy metal contamination are serious problems. In addition, not only environmental and health problems due to the exhaust gas such as mainly sulfur dioxide (SO₂) but also the generation of a huge amount of construction and demolition wastes with the accelerating urbanization has emerged as a social problem in China. Therefore, the need for the recycling and reuse of both desulfurization waste and waste concrete is very urgent and necessary. So we have investigated the effectiveness as acid soil amendments of both coal bio-briquette ash and waste concrete. In this paper, acid soil (AS1) in Nanjing (pH=6.0, EC=1.6dSm-1) and acid soil (AS2) in Guangzhou (pH=4.1, EC=0.2dSm-1) were investigated in soil amelioration test. Soil amendments were three coal bio-briquette ashes (BBA1, BBA2 and BBA3), the waste cement fine powders (CFP) ( < 200µm (particle diameter)), waste concrete particles (WCP) ( < 4.75mm ( < 0.6mm, 0.6-1.0mm, 1.0-2.0mm, 2.0-4.75mm)), and six mixtures with two coal bio-briquette ashes (BBA2 and BBA3), CFP, WCP( < 0.6mm) and WCP(2.0-4.75mm). In acid soil amelioration test, the three BBAs, CFP and various WCPs based on exchangeable calcium concentration were added to two acid soils. The application rates were from 0 wt% to 3.5 wt% in AS1 test and from 0 wt% to 6.0 wt% in AS2 test, respectively. Soil chemical properties (pH, EC, exchangeable and soluble ions (Na, Ca, Mg, K)) before and after mixing with soil amendments were measured. In addition, Al toxicity and the balance of salts (CaO, K₂O, MgO) in soil after amelioration was evaluated. The order of pH and exchangeable Ca concentration that is effective for acid soil amelioration was WCP(0.6mm) > CFP > WCP(2.0-4.25mm) > BB1 > BB2 > BB3. In all AS 1 and AS 2 amelioration tests using three BBAs, the pH and EC increased slightly with the increase of application rate and reached to the appropriate value range of both pH and EC in BBA1 only. Because BBA1 was higher value in pH and exchangeable Ca. After that, soil pH and EC with the increase in the application rate of BBA2, BBA3 and by using CFP, WC( < 0.6mm), WC(2.0-4.75mm) as soil amendment reached to each appropriate value range, respectively. In addition, the mixture amendments with BBA2, BBA3 CFP, WC( < 0.6mm), and WC(2.0-4.75mm) could ameliorate at a smaller amount of application rate in case of BBA only. And the exchangeable Al concentration decreased drastically with the increase in pH due to soil amelioration and was under the standard value. Lastly, the heavy metal (Cd, As, Se, Ni, Cr, Pb, Mo, B, Cu, Zn) contents in new soil amendments were under control standard values for agricultural use in China. Thus we could propose a new acid soil amelioration method using coal bio-briquette ash and waste concrete in China.Keywords: acid soil, coal bio-briquette ash, soil amelioration, waste concrete
Procedia PDF Downloads 1846406 Rapid Biosynthesis of Silver Nanoparticles Using Trachyspermum Ammi
Authors: Rajesh Kumar Meena, Suman Jhajharia, Goutam Chakraborty
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Plasmonic silver nanoparticles (Ag NPs) was synthesized by chemical reduction method using Trachyspermum Ammi (TA, Ajwain) seeds extract in aqueous medium and AgNO3 solution at different time interval. Reaction time, and concentration of AgNO3 and TA could accelerate the reduction rate of Ag+ and affect AgNPs size and concentration of NPs. Surface plasmon resonance band centered at 420-430 nm (88.78nm) was recognised as first exitonic peak of UV-Vis absorption spectra of AgNPs that used to calculate the particle size (10-30 nm). FTIR results TA supported AgNPs showed decrease in intensity of peaks at 3394, 1716 and 1618 cm-1 with respect to the plain TA indicating the involvement of O-H, carbonyl group and C=C stretching in formation of TA-AgNPs aggregates. The C-O-C and C-N stretching suggested the presence of many phytochemicals on the surface of the NPs. Impedance study reveals that at low concentration of TA the rate of charge transfer is in TA-AgNPs aggregates, found higher than the higher TA concentration condition that confirms the stability of AgNPs in water. Extract reduce silver ions into silver nanoparticles (NPs) of size 6-50nm. Pronounce effect of the time on Ag NPs concentration and particle size, was exhibited by the system These biogenic Ag NPs are characterized using UV- Vis spectrophotometry (UV-Visible), Fourier transformation infrared (FTIR) and XRD. These studies give us inside view of the most probable mechanism of biosynthesis and optoelectronic properties of the as synthesised Ag NPs.Keywords: antimicrobial activity, bioreduction, capping agent, silver nanoparticles
Procedia PDF Downloads 3266405 Ti-Mo-N Nano-Grains Embedded into Thin MoSₓ-Based Amorphous Matrix: A Novel Structure for Superhardness and Ultra-Low Wear
Authors: Lina Yang, Mao Wen, Jianhong Chen, Kan Zhang
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Molybdenum disulfide (MoS₂) represents a highly sought lubricant for reducing friction based on intrinsic layered structure, but for this reason, practical applications have been greatly restricted due to the fact that its low hardness would cause severe wear. Here, a novel TiMoN/MoSₓ composite coatings with TiMoN solid solution grains embedded into MoSₓ-based amorphous matrix has been successfully designed and synthesized, through magnetron co-sputtering technology. Desirably, in virtue of such special microstructure, superhardness and excellent toughness can be well achieved, along with an ultra-low wear rate at ~2×10⁻¹¹ mm³/Nm in the air environment, simultaneously, low friction at ~0.1 is maintained. It should be noted that this wear level is almost two orders of magnitude lower than that of pure TiN coating, and is, as we know, the lowest wear rate in dry sliding. Investigations of tribofilm reveal that it is amorphous MoS₂ in nature, and its formation arises directly from the MoSₓ amorphous matrix. Which contributes to effective lubrication behavior, coupled with excellent mechanical performances of such composite coating, exceptionally low wear can be guaranteed. The findings in this work suggest that the special composite structure makes it possible for the synthesis of super-hard and super-durable lubricative coating, offering guidance to synthesize ultrahigh performance protective coating for industrial application.Keywords: hardness, MoS₂-containing composite coatings, toughness, tribological properties
Procedia PDF Downloads 1556404 Introduce a New Model of Anomaly Detection in Computer Networks Using Artificial Immune Systems
Authors: Mehrshad Khosraviani, Faramarz Abbaspour Leyl Abadi
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The fundamental component of the computer network of modern information society will be considered. These networks are connected to the network of the internet generally. Due to the fact that the primary purpose of the Internet is not designed for, in recent decades, none of these networks in many of the attacks has been very important. Today, for the provision of security, different security tools and systems, including intrusion detection systems are used in the network. A common diagnosis system based on artificial immunity, the designer, the Adhasaz Foundation has been evaluated. The idea of using artificial safety methods in the diagnosis of abnormalities in computer networks it has been stimulated in the direction of their specificity, there are safety systems are similar to the common needs of m, that is non-diagnostic. For example, such methods can be used to detect any abnormalities, a variety of attacks, being memory, learning ability, and Khodtnzimi method of artificial immune algorithm pointed out. Diagnosis of the common system of education offered in this paper using only the normal samples is required for network and any additional data about the type of attacks is not. In the proposed system of positive selection and negative selection processes, selection of samples to create a distinction between the colony of normal attack is used. Copa real data collection on the evaluation of ij indicates the proposed system in the false alarm rate is often low compared to other ir methods and the detection rate is in the variations.Keywords: artificial immune system, abnormality detection, intrusion detection, computer networks
Procedia PDF Downloads 3566403 Investigation of Minor Actinide-Contained Thorium Fuel Impacts on CANDU-Type Reactor Neutronics Using Computational Method
Authors: S. A. H. Feghhi, Z. Gholamzadeh, Z. Alipoor, C. Tenreiro
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Currently, thorium fuel has been especially noticed because of its proliferation resistance than long half-life alpha emitter minor actinides, breeding capability in fast and thermal neutron flux and mono-isotopic naturally abundant. In recent years, efficiency of minor actinide burning up in PWRs has been investigated. Hence, a minor actinide-contained thorium based fuel matrix can confront both proliferation resistance and nuclear waste depletion aims. In the present work, minor actinide depletion rate in a CANDU-type nuclear core modeled using MCNP code has been investigated. The obtained effects of minor actinide load as mixture of thorium fuel matrix on the core neutronics has been studiedwith comparingpresence and non-presence of minor actinide component in the fuel matrix.Depletion rate of minor actinides in the MA-contained fuel has been calculated using different power loads.According to the obtained computational data, minor actinide loading in the modeled core results in more negative reactivity coefficients. The MA-contained fuel achieves less radial peaking factor in the modeled core. The obtained computational results showed 140 kg of 464 kg initial load of minor actinide has been depleted in during a 6-year burn up in 10 MW power.Keywords: minor actinide burning, CANDU-type reactor, MCNPX code, neutronic parameters
Procedia PDF Downloads 4576402 The Environmental Impacts of Textiles Reuse and Recycling: A Review on Life-Cycle-Assessment Publications
Authors: Samuele Abagnato, Lucia Rigamonti
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Life-Cycle-Assessment (LCA) is an effective tool to quantify the environmental impacts of reuse models and recycling technologies for textiles. In this work, publications in the last ten years about LCA on textile waste are classified according to location, goal and scope, functional unit, waste composition, impact assessment method, impact categories, and sensitivity analysis. Twenty papers have been selected: 50% are focused only on recycling, 30% only on reuse, the 15% on both, while only one paper considers only the final disposal of the waste. It is found that reuse is generally the best way to decrease the environmental impacts of textiles waste management because of the avoided impacts of manufacturing a new item. In the comparison between a product made with recycled yarns and a product from virgin materials, in general, the first option is less impact, especially for the categories of climate change, water depletion, and land occupation, while for other categories, such as eutrophication or ecotoxicity, under certain conditions the impacts of the recycled fibres can be higher. Cultivation seems to have quite high impacts when natural fibres are involved, especially in the land use and water depletion categories, while manufacturing requires a remarkable amount of electricity, with its associated impact on climate change. In the analysis of the reuse processes, relevant importance is covered by the laundry phase, with water consumption and impacts related to the use of detergents. About the sensitivity analysis, it can be stated that one of the main variables that influence the LCA results and that needs to be further investigated in the modeling of the LCA system about this topic is the substitution rate between recycled and virgin fibres, that is the amount of recycled material that can be used in place of virgin one. Related to this, also the yield of the recycling processes has a strong influence on the results of the impact. The substitution rate is also important in the modeling of the reuse processes because it represents the number of avoided new items bought in place of the reused ones. Another aspect that appears to have a large influence on the impacts is consumer behaviour during the use phase (for example, the number of uses between two laundry cycles). In conclusion, to have a deeper knowledge of the impacts of a life-cycle approach of textile waste, further data and research are needed in the modeling of the substitution rate and of the use phase habits of the consumers.Keywords: environmental impacts, life-cycle-assessment, textiles recycling, textiles reuse, textiles waste management
Procedia PDF Downloads 896401 Comparison of Two Maintenance Policies for a Two-Unit Series System Considering General Repair
Authors: Seyedvahid Najafi, Viliam Makis
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In recent years, maintenance optimization has attracted special attention due to the growth of industrial systems complexity. Maintenance costs are high for many systems, and preventive maintenance is effective when it increases operations' reliability and safety at a reduced cost. The novelty of this research is to consider general repair in the modeling of multi-unit series systems and solve the maintenance problem for such systems using the semi-Markov decision process (SMDP) framework. We propose an opportunistic maintenance policy for a series system composed of two main units. Unit 1, which is more expensive than unit 2, is subjected to condition monitoring, and its deterioration is modeled using a gamma process. Unit 1 hazard rate is estimated by the proportional hazards model (PHM), and two hazard rate control limits are considered as the thresholds of maintenance interventions for unit 1. Maintenance is performed on unit 2, considering an age control limit. The objective is to find the optimal control limits and minimize the long-run expected average cost per unit time. The proposed algorithm is applied to a numerical example to compare the effectiveness of the proposed policy (policy Ⅰ) with policy Ⅱ, which is similar to policy Ⅰ, but instead of general repair, replacement is performed. Results show that policy Ⅰ leads to lower average cost compared with policy Ⅱ.Keywords: condition-based maintenance, proportional hazards model, semi-Markov decision process, two-unit series systems
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