Search results for: gain control
Commenced in January 2007
Frequency: Monthly
Edition: International
Paper Count: 12266

Search results for: gain control

7736 Antistress Effects of Hydrangeae Dulcis Folium on Net Handing Stress-Induced Anxiety-Like Behavior in Zebrafish: Possible Mechanism of Action of Adrenocorticotropin Hormone (ACTH) Receptor

Authors: Lee Seungheon, Kim Ba-Ro

Abstract:

In this study, the anti-stress effects of the ethanolic extract of Hydrangeae Dulcis Folium (EHDF) were investigated. To determine the effects of EHDF on physical stress, changes in the whole-body cortisol level and behaviour were monitored in zebrafish. To induce physical stress, we used the net handling stress (NHS). Fish were treated with EHDF for 6 min before they were exposed to stress, and the fish were either evaluated via behavioural tests, including a novel tank test and an open field test or sacrificed to collect body fluid from the whole body. The results indicate that increased anxiety-like behaviours in the novel tank test and open field test under stress were recovered by treatment with EHDF at 5, 10 and 20 mg/L (P < 0.05). Moreover, compared with the normal group, which was not treated with NHS, the whole-body cortisol level was significantly increased by treatment with NHS in the control group. Compared with the control group, pre-treatment with EHDF at concentrations of 5, 10 and 20 mg/L for 6 min significantly prevented the increase in the whole-body cortisol level induced by NHS (P < 0.05). In addition, adrenocorticotropin hormone (ACTH) challenge studies showed that EHDF completely blocked the effects of ACTH (0.2 IU/g, IP) on cortisol secretion. These results suggest that EHDF may be a good anti-stress candidate and that its mechanism of action may be related to its positive effects on cortisol release.

Keywords: net handling stress, zebrafish, hydrangeae dulcis folium, whole-body cortisol, novel tank test, open field test

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7735 Development of a Table-Top Composite Wire Fabrication System for Additive Manufacturing

Authors: Krishna Nand, Mohammad Taufik

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Fused Filament Fabrication (FFF) is one of the most popular additive manufacturing (AM) technology. In FFF technology, a wire form material (filament) is fed inside a heated chamber, where it gets converted into semi-solid form and extruded out of a nozzle to be deposited on the build platform to fabricate the part. FFF technology is expanding and covering the market at a very rapid rate, so the need of raw materials for 3D printing is also increasing. The cost of 3D printing is directly affected by filament cost. To make 3D printing more economic, a compact and portable filament/wire extrusion system is needed. Wire extrusion systems to extrude ordinary wire/filament made of a single material are available in the market. However, extrusion system to make a composite wire/filament are not available. Hence, in this study, initial efforts have been made to develop a table-top composite wire extruder. The developed system is consisted of mechanical parts, electronics parts, and a control system. A multiple channel hopper, extrusion screw, melting chamber and nozzle, cooling zone, and spool winder are some mechanical parts. While motors, heater, temperature sensor, cooling fans are some electronics parts, which are used to develop this system. A control board has been used to control the various process parameters like – temperature and speed of motors. For the production of composite wire/filament, two different materials could be fed through two channels of hopper, which will be mixed and carried to the heated zone by extrusion screw. The extrusion screw is rotated by a motor, and the speed of this motor will be controlled by the controller as per the requirement of material extrusion rate. In the heated zone, the material will melt with the help of a heating element and extruded out of the nozzle in the form of wire. The developed system occupies less floor space due to the vertical orientation of its heating chamber. It is capable to extrude ordinary filament as well as composite filament, which are compatible with 3D printers available in the market. Further, the developed system could be employed in the research and development of materials, processing, and characterization for 3D printer. The developed system presented in this study could be a better choice for hobbyists and researchers dealing with the fused filament fabrication process to reduce the 3D printing cost significantly by recycling the waste material into 3D printer feed material. Further, it could also be explored as a better alternative for filament production at the commercial level.

Keywords: additive manufacturing, 3D Printing, filament extrusion, pellet extrusion

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7734 A Faunistic Study of Tetranychid and Phytoseiid Mites Associated with Diverse Crops From Samsun, Turkey

Authors: B. İnal, H. Di̇ler

Abstract:

This research was implemented from March to September to reveal tetranychid and phytoseiid mites on different field crops in Samsun province, Turkey. In consequence of microscope slide-mounting of mite samples in Hoyer’s medium, a total of six species belonging to Tetranychidae and fourteen species belonging to Phytoseiidae were found. Tetranychus urticae Koch, Tetranychus turkestani Ugarov and Nikolski, Tetranychus viennensis Zacher, Panonychus ulmi (Koch), Panonychus citri (Mc Gregor) and Bryobia rubrioculus (Scheuten) were detected as phytophaous mites. Euseius finlandicus (Oudemans), Kampimodromus aberrans (Oudemans), Amblyseius agrestris (Karg), Amblyseius andersoni (Chant), Amblyseius bicaudus Wainstein, Amblyseius zwölferi (Dosse), Amblyseius barkeri (Hughes), Paraseilus soleiger (Ribaga), Anthoseius recki (Wainstein), Phytoseius finitimus Ribaga, Typhlodromus pyri Scheuten, Typhloctonus tiliarum Oudemans, Phytoseiulus macropilis (Banks) and Phytoseiulus persimilis Athias-Henriot were identified to be predatory mites in Phytoseiidae. Among the phytoseiid species Kampimodromus aberrans, Amblyseius andersoni, Anthoseius recki, Phytoseius finitimus, Phytoseiulus persimilis and Phytoseiulus macropilis were widespread. Relationship between tetranychid and phytoseiid mites on different crops that can make considerable contribution to biological control in integrated pest management (IPM) programs is also reported.

Keywords: biological control, IPM, interaction, phytoseiidae, tetranychidae

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7733 Satellites and Drones: Integrating Two Systems for Monitoring Air Quality and the Stress of the Plants

Authors: Bernabeo R. Alberto

Abstract:

Unmanned aerial vehicles (UAV) platforms or remotely piloted aircraft system (Rpas) - with dedicated sensors - are fundamental support to the planning, running, and control of the territory in which public safety is or may be at risk for post-disaster assessments such as flooding or landslides, for searching lost people, for crime and accident scene photography, for assisting traffic control at major events, for teaching geography, history, natural science and all those subjects that require a continuous cyclical process of observation, evaluation and interpretation. Through the use of proximal remote sensing information related to anthropic landscape and nature integration, there is an opportunity to improve knowledge and management decision-making for the safeguarding of the environment, for farming, wildlife management, land management, mapping, glacier monitoring, atmospheric monitoring, for the conservation of archeological, historical, artistic and architectural sites, allowing an exact delimitation of the site in the territory. This paper will go over many different mission types. Within each mission type, it will give a broad overview to familiarize the reader but not make them an expert. It will also give detailed information on the payloads and other testing parameters the Unmanned Aerial Vehicles (UAV) use to complete a mission. The project's goal is to improve satellite maps about the stress of the plants, air quality monitoring, and related health issues.

Keywords: proximal remote sensing, remotely piloted aircraft system, risk, safety, unmanned aerial vehicle

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7732 Relation of Urinary Microalbumin with Glycosylated Hemoglobin (HbA1c) and Duration of Type 2 Diabetes Mellitus (T2DM) in Selected Male and Female Patients

Authors: Junaid Mahmood Alam, Howarh Humaira Ali, Ishrat Sultana

Abstract:

Long term irregularity in the glycemic state, especially in Type 2 diabetes mellitus (T2DM) patients, depicted by higher levels of HbA1c, is noted to be correlated with the development of microalbuminuria. The aim of the current study is to investigate the association of urinary microalbumin with HbA1c and with duration of diabetes mellitus in selected male and female T2DM patients. This cross-sectional study was carried out in a total of 70 patients, thirty-five each male and females with diagnosed T2DM, within the age group of 35-60 years. Biochemical parameters of urea, creatinine, urinary microalbumin, HbA1c, fasting blood glucose and post- parendial blood glucose were determined by standard methods. Data was statistically examined by student’s t-test and Pearson’s correlation. Results showed that comparison of healthy control subjects with both male and female T2DM patients depicted significantly elevated levels of all parameters in (P < 0.05 to P < 0.001). Comparison of duration of T2DM with the existence of urinary microalbumin was moderately significant (P < 0.05) when duration was less than 4 years, significant (P < 0.01) with duration of 4-6 years and markedly significant (P < 0.001) with duration of more than 6 years. It is concluded that in male and female T2DM patients, duration of DM as well as poor glycemic control, depicted by higher levels of HbA1c is significantly correlated with elevated levels of urinary microalbumin.

Keywords: type 2 diabetes mellitus, glycosylated hemoglobin, urinary microalbumin, T2DM, HbA1c

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7731 SWOT Analysis of the Industrial Sector in Kuwait

Authors: Abdullah Al-Alaian, Ahmad Al-Enzi, Hasan Al-Herz, Ahmad Bakri, Shant Tatorian, Amr Nounou

Abstract:

Kuwait is a country that has an imbalanced economy since most of its national outcome comes from the oil trade. It is so risky for a country to be dependent on a single source for income, and this increases the need to diversify its economy. In addition, according to the Public Authority for Industry, the contribution of the industrial sector to the current Gross Domestic Product (GDP) of Kuwait is low which is about 4.33%. Therefore, the development of the industrial sector can be one of the means to diversify the economy and increase the industry's contribution to the national outcome. This is in accordance with Kuwait’s vision of 2035 which aims at increasing the contribution of the industrial sector to the GDP to 12%. In order to do so, this study aims at proposing a strategic plan that will accomplish certain objectives when implemented. It is based on analyzing the industrial sectors in Kuwait taking into consideration studying the strengths, weaknesses, opportunities, and threats facing them. At the same time, it tends to gain from the experience of leading models and neighboring countries regarding the development of the industrial sector. In this study, the SWOT analysis technique will be conducted on all industrial sectors based on evaluation criteria in which it is determined whether any of them has a potential for improvement or not. In other words, it is determined whether the sectors are able to compete locally, regionally, or globally. Based on the results of the SWOT analysis, certain sectors will be chosen, assessed based on an assessment scheme, and their potentials for improvement will be aligned with the overall objectives. To ensure the achievement of the study’s objectives, an action plan will be proposed regarding recommendations for the related authorities, and for entrepreneurs. In addition, monitoring tools are going to be provided for the purpose of periodically checking the progress made in the implementation of the plan.

Keywords: industrial sector, SWOT analysis, productivity, competitiveness, GDP, Kuwait, economy

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7730 Governance and Financial Constraints the Impact on Corporate Social Responsibility Implementation in Cooperatives

Authors: Wanlapha Phraibueng, Patrick Sentis, Geraldine Riviere-Giordano

Abstract:

Corporate Social Responsibility (CSR) initiatives have been widely discussed especially in investor-oriented firms. In contrast, cooperatives pay less attention to CSR because their activities have integrated the responsibility and the solidity of social, economic and environment. On the other hand, by adopting ownership theory and agency theory – cooperatives ignore CSR investment due to unclarified decision control in the governance and the limitation to acquire the capital financed. The unique governance and financial structures in cooperatives lead to the conflict among the stakeholders and long-term investment which have an impact on firm financial performance. As an illustration of cooperatives dilemmas, we address the question of Whether or not cooperatives in term of governance and financial structures are the constraints on implementing CSR policies. We find that the governance and financial structures in large cooperatives are the influence factors which predispose cooperatives to invest on CSR. In contrast, in the startup or small cooperatives, its governance and financial structures are the constraints on implementing CSR policies. We propose the alternative financial structure based on the trade-off between debt and equity which aims to relax the restrictions in cooperatives’ governance and allow cooperatives to acquire the capital financed either from its members or non-members. We suggest that engaging equity as a financial structure induces cooperatives to invest on CSR policies. Alternative financial structure eliminates not only cooperative ownership control problem but also the constraints in capital acquisition. By implementing CSR activities consistent with the alternative financial choice, cooperatives can increase firm’s value and reduce the conflict among their stakeholders.

Keywords: cooperatives, corporate social responsibility, financial, governance

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7729 Investigation on Single Nucleotide Polymorphism in Candidate Genes and Their Association with Occurrence of Mycobacterium avium Subspecies Paratuberculosis Infection in Cattle

Authors: Ran Vir Singh, Anuj Chauhan, Subhodh Kumar, Rajesh Rathore, Satish Kumar, B Gopi, Sushil Kumar, Tarun Kumar, Ramji Yadav, Donna Phangchopi, Shoor Vir Singh

Abstract:

Paratuberculosis caused by Mycobacterium avium subspecies paratuberculosis (MAP) is a chronic granulomatous enteritis affecting ruminants. It is responsible for significant economic losses in livestock industry worldwide. This organism is also of public health concern due to an unconfirmed link to Crohn’s disease. Susceptibility to paratuberculosis has been suggested to have genetic component with low to moderate heritability. Number of SNPs in various candidates genes have been observed to be affecting the susceptibility toward paratuberculosis. The objective of this study was to explore the association of various SNPs in the candidate genes and QTL region with MAP. A total of 117 SNPs from SLC11A1, IFNG, CARD15, TLR2, TLR4, CLEC7A, CD209, SP110, ANKARA2, PGLYRP1 and one QTL were selected for study. A total of 1222 cattle from various organized herds, gauhsalas and farmer herds were screened for MAP infection by Johnin intradermal skin test, AGID, serum ELISA, fecal microscopy, fecal culture and IS900 blood PCR. Based on the results of these tests, a case and control population of 200 and 183 respectively was established for study. A total of 117 SNPs from 10 candidate genes and one QTL were selected and validated/tested in our case and control population by PCR-RFLP technique. Data was analyzed using SAS 9.3 software. Statistical analysis revealed that, 107 out of 117 SNPs were not significantly associated with occurrence of MAP. Only SNP rs55617172 of TLR2, rs8193046 and rs8193060 of TLR4, rs110353594 and rs41654445 of CLEC7A, rs208814257of CD209, rs41933863 of ANKRA2, two loci {SLC11A1(53C/G)} and {IFNG (185 G/r) } and SNP rs41945014 in QTL region was significantly associated with MAP. Six SNP from 10 significant SNPs viz., rs110353594 and rs41654445 from CLEC7A, rs8193046 and rs8193060 from TLR4, rs109453173 from SLC11A1 rs208814257 from CD209 were validated in new case and control population. Out of these only one SNP rs8193046 of TLR4 gene was found significantly associated with occurrence of MAP in cattle. ODD ratio indicates that animals with AG genotype were more susceptible to MAP and this finding is in accordance with the earlier report. Hence it reaffirms that AG genotype can serve as a reliable genetic marker for indentifying more susceptible cattle in future selection against MAP infection in cattle.

Keywords: SNP, candidate genes, paratuberculosis, cattle

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7728 Assessing Native Plant Presence and Maintenance Resource Allocations in New Zealand Backyards: A Nationwide Online Questionnaire

Authors: Megan Burfoot, Shanta Budha-Magar, Ali Ghaffarianhoseini, Amirhoseini Ghaffarianhoseini

Abstract:

Domestic backyards offer a valuable opportunity to contribute to biodiversity conservation efforts and promote ecological sustainability by cultivating native plant species. This study focuses on assessing the presence and maintenance of native plants in New Zealand's residential gardens through an online questionnaire. The survey was designed to collect data on the presence of native, exotic, and lawn plants in New Zealand backyards, alongside the allocation of maintenance resources for each category. Targeting a diverse range of residents and property sizes from different regions of New Zealand, this study sought to gain essential insights into practices related to native plant cultivation. Results reveal there is a collective inclination to reduce lawn coverage and introduce a higher abundance of native and exotic species. A thorough analysis of maintenance practices reveals a significant portion of respondents embracing environmentally friendly gardening, characterized by low-intensity fertilizer usage. Homeowners, especially those residing in their properties, demonstrate proactive engagement in backyard maintenance. Native plants were found to require more time, money and fertilizer for maintenance than those of exotic and lawn species. The insights gained from this study can guide targeted efforts to enhance urban biodiversity, making a significant contribution to the preservation and enrichment of New Zealand's unique biodiversity and ecological heritage in urban settings.

Keywords: biodiversity, backyards, planting behaviour, backyard maintenance, native planting

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7727 Integrating Life Skills Education for Mental Health and Academic Benefits of Adolescents in Schools in Schools

Authors: Sarwat Sultan, Muhammad Saleem, Frasat Kanwal

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Adolescence is a transition period of life that brings physical and psychological changes and always results in several challenges for an adolescent. An adolescent must learn life skills for a healthy transition from adolescence period to adulthood. Therefore this study was planned to examine the effects of life skill education on adolescents' mental health and academic benefits. A random sample of 720 school students aged between 13-17 years was categorized into two groups; experimental (n=360) and control (n=360). Life skill education was given to the students of the intervention group with repeated assessments of mental health and academic benefits at pre-intervention (T1) and post-intervention (T2) for both groups. Both groups were compared on scores of mental health and academic benefits across two times T1 and T2 by employing a mixed between-within-subjects analysis of variance. Findings showed the main effect of time suggesting the largest changes in mental health and academic benefits over time. Interaction effects between time and both groups were also found significant indicating the largest changes across time between both groups. Results of between-group comparisons showed significant values for Wilks’ Lambda and partial eta squared for students of the intervention group who scored higher on mental health and academic benefits after receiving life skills training than the students of the control group. Results of the present study determined the efficacy of life skill education and have implications for both teachers and psychotherapists to improve the students’ mental health and academic performance.

Keywords: academic benefits, life skills, mental health, adolescents

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7726 Learners’ Violent Behaviour and Drug Abuse as Major Causes of Tobephobia in Schools

Authors: Prakash Singh

Abstract:

Many schools throughout the world are facing constant pressure to cope with the violence and drug abuse of learners who show little or no respect for acceptable and desirable social norms. These delinquent learners tend to harbour feelings of being beyond reproach because they strongly believe that it is well within their rights to engage in violent and destructive behaviour. Knives, guns, and other weapons appear to be more readily used by them on the school premises than before. It is known that learners smoke, drink alcohol, and use drugs during school hours, hence, their ability to concentrate, work, and learn, is affected. They become violent and display disruptive behaviour in their classrooms as well as on the school premises, and this atrocious behaviour makes it possible for drug dealers and gangsters to gain access onto the school premises. The primary purpose of this exploratory quantitative study was therefore to establish how tobephobia (TBP), caused by school violence and drug abuse, affects teaching and learning in schools. The findings of this study affirmed that poor discipline resulted in producing poor quality education. Most of the teachers in this study agreed that educating learners who consumed alcohol and other drugs on the school premises resulted in them suffering from TBP. These learners are frequently abusive and disrespectful, and resort to violence to seek attention. As a result, teachers feel extremely demotivated and suffer from high levels of anxiety and stress. The word TBP will surely be regarded as a blessing by many teachers throughout the world because finally, there is a word that will make people sit up and listen to their problems that cause real fear and anxiety in schools.

Keywords: aims and objectives of quality education, debilitating effects of tobephobia, fear of failure associated with education, learners' violent behaviour and drug abuse

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7725 Facing Global Competition through Participation in Global Innovation Networks: The Case of Mechatronics District in the Veneto Region

Authors: Monica Plechero

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Many firms belonging to Italian industrial districts faced a crisis starting from 2000 and upsurging during 2008-2014. To remain competitive in the global market, these firms and their local systems need to renovate their traditional competitive advantages, strengthen their link with global flows of knowledge. This may be particularly relevant in sectors such as the mechatronics, that combine traditional knowledge domain with new knowledge domains (e.g. mechanics, electronics, and informatics). This sector is nowadays one of the key sectors within the so-called ‘smart specialization strategy’ that can lead part of the Italian traditional industry towards new economic developmental opportunities. This paper, by investigating the mechatronics district of the Veneto region, wants to shed new light on how firms of a local system can gain from the globalization of innovation and innovation networks. Methodologically, the paper relies on primary data collected through a survey targeting firms of the local system, as well as on a number of qualitative case studies. The relevant role of medium size companies in the district emerges as evident, as they have wider opportunities to be involved in different processes of globalization of innovation. Indeed, with respect to small companies, the size of medium firms allows them to exploit strategically international markets and globally distributed knowledge. Supporting medium firms’ global innovation strategies, and incentivizing their role as district gatekeepers, may strengthen the competitive capability of the local system and provide new opportunities to positively face global competition.

Keywords: global innovation network, industrial district, internationalization, innovation, mechatronics, Veneto region

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7724 Factors Affecting Access to Education: The Experiences of Parents of Children Who Are Deaf or Hard of Hearing

Authors: Hanh Thi My Nguyen

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The purpose of this research is to examine the experiences of parents of children who are deaf or hard of hearing in supporting their children to access education in Vietnam. Parents play a crucial role in supporting their children to gain full access to education. It was widely reported that parents of those children confronted a range of problems to support their children to access education. To author’s best knowledge, there has been a lack of research exploring the experiences of those parents in literature. This research examines factors affecting those parents in supporting their children to access education. To conduct the study, qualitative approach using a phenomenological research design was chosen to explore the central phenomena. Ten parents of children who were diagnosed as deaf or hard of hearing and aged 6-9 years were recruited through the support of the Association of Parents of Children with Hearing Impairment. Participants were interviewed via telephone with a mix of open and closed questions; interviews were audio recorded, transcribed and thematically analysed. The research results show that there are nine main factors that affected the parents in this study in making decisions relating to education for their children including: lack of information resources, perspectives of those parents on communication approaches, the families’ financial capacity, the psychological impact on the participants after their children’ diagnosis, the attitude of family members, attitude of school administrators, lack of local schools and qualified teachers, and current education system for the deaf in Vietnam. Apart from those factors, the lack of knowledge of the participants’ partners about deaf education and the partners’ employment are barriers to educational access and successful communication with their child.

Keywords: access to education, deaf, hard of hearing, parents experience

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7723 Social Media Idea Ontology: A Concept for Semantic Search of Product Ideas in Customer Knowledge through User-Centered Metrics and Natural Language Processing

Authors: Martin H¨ausl, Maximilian Auch, Johannes Forster, Peter Mandl, Alexander Schill

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In order to survive on the market, companies must constantly develop improved and new products. These products are designed to serve the needs of their customers in the best possible way. The creation of new products is also called innovation and is primarily driven by a company’s internal research and development department. However, a new approach has been taking place for some years now, involving external knowledge in the innovation process. This approach is called open innovation and identifies customer knowledge as the most important source in the innovation process. This paper presents a concept of using social media posts as an external source to support the open innovation approach in its initial phase, the Ideation phase. For this purpose, the social media posts are semantically structured with the help of an ontology and the authors are evaluated using graph-theoretical metrics such as density. For the structuring and evaluation of relevant social media posts, we also use the findings of Natural Language Processing, e. g. Named Entity Recognition, specific dictionaries, Triple Tagger and Part-of-Speech-Tagger. The selection and evaluation of the tools used are discussed in this paper. Using our ontology and metrics to structure social media posts enables users to semantically search these posts for new product ideas and thus gain an improved insight into the external sources such as customer needs.

Keywords: idea ontology, innovation management, semantic search, open information extraction

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7722 Evaluation of the Skid Resistance of Asphalt Concrete Made of Local Low-Performance Aggregates Based on New Accelerated Polishing Machine

Authors: Saci Abdelhakim Ferkous, Khedoudja Soudani, Smail Haddadi

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This paper presents the results of a laboratory experimental study that explores the skid resistance of asphalt concrete mixtures made of local low-performance aggregates by partially replacing sand with olive mill waste (OMW). OMW was mixed with aggregates using a dry process by replacing sand with contents of 5%, 7%, 10% and 15%. The mechanical performances of the mixtures were evaluated using the Marshall and Duriez tests. A modified accelerated polishing machine was used as polishing equipment, and a British pendulum tester (BPT) was used to test the skid resistance of the samples. Finally, texture parameter analysis was performed using scanning electron microscopy (SEM) and Mountains Map software to assess the effect of OMW on the friction coefficient evolution. Using a distinct road wheel for a modified version of an accelerated polishing machine, which is normally used to determine the polished stone value of aggregates, the results showed that the addition of OMW up to 10% conferred a better skid resistance in comparison to normal asphalt concrete. The presence of olive mill waste in the mixture until 15% guarantees a gain of 22%-29% in skid resistance after polishing compared with the reference mix. Indeed, from texture parameter analysis, it was observed that there was differential wear of the lightweight aggregates (OMW) compared to the other aggregates during the polishing process, which created a new surface microtexture that had new peaks and led to a good level of friction compared to the mixtures without OMW. In general, it was found that OMW is a promising modifier for asphalt mixtures with both engineering and economic merits.

Keywords: skid resistance, olive mill waste, polishing resistance, accelerated polishing machine, local materials, sustainable development.

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7721 The Influence of Air Temperature Controls in Estimation of Air Temperature over Homogeneous Terrain

Authors: Fariza Yunus, Jasmee Jaafar, Zamalia Mahmud, Nurul Nisa’ Khairul Azmi, Nursalleh K. Chang, Nursalleh K. Chang

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Variation of air temperature from one place to another is cause by air temperature controls. In general, the most important control of air temperature is elevation. Another significant independent variable in estimating air temperature is the location of meteorological stations. Distances to coastline and land use type are also contributed to significant variations in the air temperature. On the other hand, in homogeneous terrain direct interpolation of discrete points of air temperature work well to estimate air temperature values in un-sampled area. In this process the estimation is solely based on discrete points of air temperature. However, this study presents that air temperature controls also play significant roles in estimating air temperature over homogenous terrain of Peninsular Malaysia. An Inverse Distance Weighting (IDW) interpolation technique was adopted to generate continuous data of air temperature. This study compared two different datasets, observed mean monthly data of T, and estimation error of T–T’, where T’ estimated value from a multiple regression model. The multiple regression model considered eight independent variables of elevation, latitude, longitude, coastline, and four land use types of water bodies, forest, agriculture and build up areas, to represent the role of air temperature controls. Cross validation analysis was conducted to review accuracy of the estimation values. Final results show, estimation values of T–T’ produced lower errors for mean monthly mean air temperature over homogeneous terrain in Peninsular Malaysia.

Keywords: air temperature control, interpolation analysis, peninsular Malaysia, regression model, air temperature

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7720 Meld of Lactobacillus and Rangiferinus for Emendation of Endotoxemia in Alcoholic Liver Damage in Rats

Authors: Shukla Ila, Azmi Lubna, S. S. Gupta, Ch. V. Rao

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Oxidative stress has been increasingly associated with the induction and progression of liver damage. The current study was conducted to record the effect of combination of Lactobacillus and Lichen rangiferinus extract (LRE + Lac) on the severity of injury in experimental alcoholic liver disease and how it affects plasma levels of prostaglandin E2, endotoxin, thromboxane B2, and leukotriene B4. Male Wistar rats were grouped into five comprising six animals in each group. Group 1 served as negative control. Groups 2-5 were administered 10% ethanol for six weeks. Group 3 was administered with extract (200 mg/kg), group 4 received the diet containing 10% ethanol plus a bolus of lactobacilli GG (1010 CFU), and group 5 animals were given silymarin along with alcohol and it served as positive control. Aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, total protein content, γ-glutamyltransferase, glutathione S-transferase, oxidative stress markers, glutathione, malondialdehyde and glutathione reductase were determined using standard diagnostic kits. Histopathological analysis of liver tissue was also made. A positive relation was found between plasma endotoxin levels and degree of liver injury. The pathology records were also related positively with leukotriene B4 and thromboxane B2. But a negative correlation was obtained with PgE2 levels. This study led us to hypothesize that the increased endotoxin levels modulate liver metabolism of eicosanoid, which gradually leads to liver injury. Endotoxemia increases leukotriene and thromboxane levels in plasma.

Keywords: lactobacillus, Lichen rangiferinus, endotoxemia, silymarin

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7719 Biological Soil Crust Effects on Dust Control Around the Urmia Lake

Authors: Abbas Ahmadi, Nasser Aliasgharzad, Ali Asghar Jafarzadeh

Abstract:

Nowadays, drying of the Urmia Lake as a largest saline lake in the world and emerging its saline bed from water has caused the risk of salty dune storms, which threats the health of human society and also plants and animal communities living in the region. Biological soil crusts (BSCs) as a dust stabilizer attracted the attention of Soil conservation experts in recent years. Although the presence of water by the impenetrable lake bed and endorheic basin can be an advantage to create BSCs, but the extraordinary of the lake bed salinity is a factor for prevention of its establishment in the region. Therefore, the present research work has been carried out to investigate the effects of inoculating the Cyanobacteria, algae and their combination to create BSCs for dust control. In this study, an algae attributed to Chlamydomonas sp and a cyanobacteria attributed to Anabaena sp isolated from the soils of Urmia Lake margin were used to create BSC in four soil samples which collected from 0-10 cm of the current margin (A), the previous bed (B), affected lands by lake (C) and Quomtappe sand dune (D). The main characteristics of the A, B and C soil samples are their highly salinity (their ECe are 108, 140 and 118 dS/m, respectively) and sodicity. Also, texture class of the soil A was loamy sand, and other two soils had clay textures. Soil D was Non-saline, but it was sodic with a sandy texture class. This study was conducted separately in each soil in a completely randomized design under four inoculation treatments of non-inoculated (T0), Algae (T1), cyanobacteria (T2) and equal mixture of algae and cyanobacteria (T3) with three replications. In the experiment, the soil was placed into wind tunnel trays, and a suspension containing microorganisms mixed with the trays surface soil. During the experiment, water was sprayed to the trays at the morning and evening of every day. After passing the incubation period (30 days), some characteristics of samples such as pH, EC, cold water extractable carbohydrate (CWEC), hot water extractable carbohydrate (HWEC), sulfuric acid extractable carbohydrate (SAEC), organic matter, crust thickness, penetration resistance, wind erosion threshold velocity and soil loss in the wind tunnel were measured, and Correlation between the measured characteristics was obtained through the SPSS software. Analysis of variance and so comparison between the means of treatments were analyzed with MSTATC software. In this research, Chlorophyll, an amount, was used as an indicator of the microorganism's population in the samples. Based on obtained results, the amount of Chlorophyll a in the T2 treatment of soil A and all treatments of soil D was significantly increased in comparison to the control and crust thickness showed increase in all treatments by microorganism’s inoculation. But effect of the treatments was significant in soils A and D. At all treatment’s inoculation of microorganisms in soil A caused to increase %46, %34 and %55 of the wind erosion threshold velocity in T1, T2 and T3 treatments in comparison to the control, respectively, and in soil D all treatments caused wind erosion threshold velocity became two times more than control. However, soil loss in the wind tunnel experiments was significant in T2 and T3 treatments of these soils and T1 treatment had no effect in reducing soil loss. Correlation between Chlorophyll a and salinity shows the important role of salinity in microbial growth prevention and formation of BSCs in the studied samples. In general, according to the obtained results, it can be concluded that salinity reduces the growth of microorganisms in saline soils of the region, and in soils with fine textures, salinity role in prevention of the microbial growth is clear. Also, using the mix of algae and cyanobacteria together caused the synergistic growth of them and consequently, better protection of the soil against wind erosion was provided.

Keywords: wind erosion, algae, cyanobacteria, carbohydrate

Procedia PDF Downloads 63
7718 Understanding the Qualitative Nature of Product Reviews by Integrating Text Processing Algorithm and Usability Feature Extraction

Authors: Cherry Yieng Siang Ling, Joong Hee Lee, Myung Hwan Yun

Abstract:

The quality of a product to be usable has become the basic requirement in consumer’s perspective while failing the requirement ends up the customer from not using the product. Identifying usability issues from analyzing quantitative and qualitative data collected from usability testing and evaluation activities aids in the process of product design, yet the lack of studies and researches regarding analysis methodologies in qualitative text data of usability field inhibits the potential of these data for more useful applications. While the possibility of analyzing qualitative text data found with the rapid development of data analysis studies such as natural language processing field in understanding human language in computer, and machine learning field in providing predictive model and clustering tool. Therefore, this research aims to study the application capability of text processing algorithm in analysis of qualitative text data collected from usability activities. This research utilized datasets collected from LG neckband headset usability experiment in which the datasets consist of headset survey text data, subject’s data and product physical data. In the analysis procedure, which integrated with the text-processing algorithm, the process includes training of comments onto vector space, labeling them with the subject and product physical feature data, and clustering to validate the result of comment vector clustering. The result shows 'volume and music control button' as the usability feature that matches best with the cluster of comment vectors where centroid comments of a cluster emphasized more on button positions, while centroid comments of the other cluster emphasized more on button interface issues. When volume and music control buttons are designed separately, the participant experienced less confusion, and thus, the comments mentioned only about the buttons' positions. While in the situation where the volume and music control buttons are designed as a single button, the participants experienced interface issues regarding the buttons such as operating methods of functions and confusion of functions' buttons. The relevance of the cluster centroid comments with the extracted feature explained the capability of text processing algorithms in analyzing qualitative text data from usability testing and evaluations.

Keywords: usability, qualitative data, text-processing algorithm, natural language processing

Procedia PDF Downloads 285
7717 Analysis of the Level of Production Failures by Implementing New Assembly Line

Authors: Joanna Kochanska, Dagmara Gornicka, Anna Burduk

Abstract:

The article examines the process of implementing a new assembly line in a manufacturing enterprise of the household appliances industry area. At the initial stages of the project, a decision was made that one of its foundations should be the concept of lean management. Because of that, eliminating as many errors as possible in the first phases of its functioning was emphasized. During the start-up of the line, there were identified and documented all production losses (from serious machine failures, through any unplanned downtime, to micro-stops and quality defects). During 6 weeks (line start-up period), all errors resulting from problems in various areas were analyzed. These areas were, among the others, production, logistics, quality, and organization. The aim of the work was to analyze the occurrence of production failures during the initial phase of starting up the line and to propose a method for determining their critical level during its full functionality. There was examined the repeatability of the production losses in various areas and at different levels at such an early stage of implementation, by using the methods of statistical process control. Based on the Pareto analysis, there were identified the weakest points in order to focus improvement actions on them. The next step was to examine the effectiveness of the actions undertaken to reduce the level of recorded losses. Based on the obtained results, there was proposed a method for determining the critical failures level in the studied areas. The developed coefficient can be used as an alarm in case of imbalance of the production, which is caused by the increased failures level in production and production support processes in the period of the standardized functioning of the line.

Keywords: production failures, level of production losses, new production line implementation, assembly line, statistical process control

Procedia PDF Downloads 128
7716 Extraction and Quantification of Peramine Present in Dalaca pallens, a Pest of Grassland in Southtern Chile

Authors: Leonardo Parra, Daniel Martínez, Jorge Pizarro, Fernando Ortega, Manuel Chacón-Fuentes, Andrés Quiroz

Abstract:

Control of Dalaca pallens or blackworms, one of the most important hypogeous pest in grassland in southern Chile, is based on the use of broad-spectrum insecticides such as organophosphates and pyrethroids. However, the rapid development of insecticide resistance in field populations of this insect and public concern over the environmental impact of these insecticides has resulted in the search for other control methods. Specifically, the use of endophyte fungi for controlling pest has emerged as an interesting and promising strategy. Endophytes from ryegrass (Lolium perenne), establish a biotrophic relationship with the host, defined as mutualistic symbiosis. The plant-fungi association produces alkaloids where peramine is the main toxic substance against Listronotus bonariensis, the most important epigean pest of ryegrass. Nevertheless, the effect of peramina on others pest insects, such as D. pallens, to our knowledge has not been studied, and also its possible metabolization in the body of the larvae. Therefore, we addressed the following research question: Do larvae of D. pallens store peramine after consumption of ryegrass endophyte infected (E+)? For this, specimens of blackworms were fed with ryegrass plant of seven experimental lines and one commercial cultivar endophyte free (E-) sown at the Instituto de Investigaciones Agropecuarias Carillanca (Vilcún, Chile). Once the feeding period was over, ten larvae of each treatment were examined. Individuals were dissected, and their gut was removed to exclude any influence of remaining material. The rest of the larva's body was dried at 60°C by 24-48 h and ground into a fine powder using a mortar. 25 mg of dry powder was transferred to a microcentrifuge tube and extracted in 1 mL of a mixture of methanol:water:formic acid. Then, the samples were centrifuged at 16,000 rpm for 3 min, and the supernatant was colected and injected in the liquid chromatography of high resolution (HPLC). The results confirmed the presence of peramine in the larva's body of D. pallens. The insects that fed the experimental lines LQE-2 and LQE-6 were those where peramine was present in high proportion (0.205 and 0.199 ppm, respectively); while LQE-7 and LQE-3 obtained the lowest concentrations of the alkaloid (0.047 and 0.053 ppm, respectively). Peramine was not detected in the insects when the control cultivar Jumbo (E-) was tested. These results evidenced the storage and metabolism of peramine during consumption of the larvae. However, the effect of this alkaloid present in 'future ryegrass cultivars' (LQE-2 and LQE-6) on the performance and survival of blackworms must be studied and confirmed experimentally.

Keywords: blackworms, HPLC, alkaloid, pest

Procedia PDF Downloads 304
7715 Changes of Mitochondrial Potential in the Midgut Epithelium of Lithobius forficatus (Myriapoda, Chilopoda) Exposed to Cadmium Concentrated in Soil

Authors: Magdalena Rost-Roszkowska, Izabela Poprawa, Alina Chachulska-Zymelka, Lukasz Chajec, Grazyna Wilczek, Piotr Wilczek, Malgorzata Lesniewska

Abstract:

Lithobius forficatus, commonly known as the brown centipede, is a widespread European species, which lives in the upper layers of soil, under stones, litter, rocks, and leaves. As the soil organism, it is exposed to numerous stressors such as xenobiotics, including heavy metals, temperature, starvation, pathogens, etc. Heavy metals are treated as the environmental pollutants of the soil because of their toxic effects on plants, animals and human being. One of the heavy metals which is xenobiotic and can be taken up by plants or animals from the soil is cadmium. The digestive system of centipedes is composed of three distinct regions: fore-, mid- and hindgut. The salivary glands of centipedes are the organs which belong to the anterior region of the digestive system and take part in the synthesis, accumulation, and secretion of many substances. The middle region having contact with the food masses is treated as one of the barriers which protect the organism against any stressors which originate from the external environment, e.g., toxic metals. As the material for our studies, we chose two organs of the digestive system in brown centipede, the organs which take part in homeostasis maintenance: the salivary glands and the midgut. The main purpose of the project was to investigate the relationship between the percentage of depolarized mitochondria, mitophagy and ATP level in cells of mentioned above organs. The animals were divided into experimental groups: K – the control group, the animals cultured in a laboratory conditions in a horticultural soil and fed with Acheta domesticus larvae; Cd1 – the animals cultured in a horticultural soil supplemented with 80 mg/kg (dry weight) of CdCl2, fed with A. domesticus larvae maintained in tap water, 12 days – short-term exposure; Cd2 – the animals cultured in a horticultural soil supplemented with 80 mg/kg (dry weight) of CdCl2, fed with A. domesticus larvae maintained in tap water, 45 days – long-term exposure. The studies were conducted using transmission electron microscopy (TEM), flow cytometry and confocal microscopy. Quantitative analysis revealed that regardless of the organ, a progressive increase in the percentage of cells with depolarized mitochondria was registered, but only in the salivary glands. These were statistically significant changes from the control. In both organs, there were no differences in the level of the analyzed parameter depending on the duration of exposure of individuals to cadmium. Changes in the ultrastructure of mitochondria have been observed. With the extension of the body's exposure time to metal, an increase in the ADP/ATP index was recorded. However, changes statistically significant to the control were demonstrated in the intestine and salivary glands. The size of this intestinal index and salivary glands in the Cd2 group was about thirty and twenty times higher, respectively than in control. Acknowledgment: The study has been financed by the National Science Centre, Poland, grant no 2017/25/B/NZ4/00420.

Keywords: cadmium, digestive system, ultrastructure, centipede

Procedia PDF Downloads 136
7714 Identification and Characterization of Groundwater Recharge Sites in Kuwait

Authors: Dalal Sadeqi

Abstract:

Groundwater is an important component of Kuwait’s water resources. Although limited in quantity and often poor in quality, the significance of this natural source of water cannot be overemphasized. Recharge of groundwater in Kuwait occurs during periodical storm events, especially in open desert areas. Runoff water dissolves accumulated surficial meteoric salts and subsequently leaches them into the groundwater following a period of evaporative enrichment at or near the soil surface. Geochemical processes governing groundwater recharge vary in time and space. Stable isotope (18O and 2H) and geochemical signatures are commonly used to gain some insight into recharge processes and groundwater salinization mechanisms, particularly in arid and semiarid regions. This article addresses the mechanism used in identifying and characterizing the main water shed areas in Kuwait using stable isotopes in an attempt to determine favorable groundwater recharge sites in the country. Stable isotopes of both rainwater and groundwater were targeted in different hydrogeological settings. Additionally, data and information obtained from subsurface logs in the study area were collected and analyzed to develop a better understanding of the lateral and vertical extent of the groundwater aquifers. Geographic Information System (GIS) and RockWorks 3D modelling software were used to map out the hydrogeomorphology of the study area and the subsurface lithology of the investigated aquifers. The collected data and information, including major ion chemistry, isotopes, subsurface characteristics, and hydrogeomorphology, were integrated in a GIS platform to identify and map out suitable natural recharge areas as part of an integrated water resources management scheme that addresses the challenges of the sustainability of the groundwater reserves in the country.

Keywords: scarcity, integrated, recharge, isotope

Procedia PDF Downloads 115
7713 Postoperative Pain Management: Efficacy of Caudal Tramadol in Pediatric Lower Abdominal Surgery: A Randomized Clinical Study

Authors: Reza Farahmand Rad, Farnad Imani, Azadeh Emami, Reza Salehi, Ali Reza Ghavamy, Ali Nima Shariat

Abstract:

Background: One of the methods of pain control after pediatric surgical procedures is regional techniques, including caudal block, despite their limitations. Objectives: In this study, the pain score and complications of caudal tramadol were evaluated in pediatrics following lower abdom- inal surgery. Methods: In this study, 46 children aged 3 to 10 years were allocated into two equal groups (R and TR) for performing caudal anal- gesia after lower abdominal surgery. The injectate contained 0.2% ropivacaine 1 mL/kg in the R group (control group) and tramadol (2 mg/kg) and ropivacaine in the TR group. The pain score, duration of pain relief, amount of paracetamol consumption, hemody- namic alterations, and possible complications at specific times (1, 2, and 6 hours) were evaluated in both groups. Results: No considerable difference was observed in the pain score between the groups in the first and second hours (P > 0.05). However, in the sixth hour, the TR group had a significantly lower pain score than the R group (P < 0.05). Compared to the R group, the TR group had a longer period of analgesia and lower consumption of analgesic drugs (P < 0.05). Heart rate and blood pressure differences were not significant between the two groups (P > 0.05). Similarly, the duration of operation and recovery time were not remarkably different between the two groups (P > 0.05). Complications had no apparent differences between these two groups, as well (P > 0.05). Conclusions: In this study, the addition of tramadol to caudal ropivacaine in pediatric lower abdominal surgery promoted pain relief without complications.

Keywords: tramadol, ropivacaine, caudal block, pediatric, lower abdominal surgery, postoperative pain

Procedia PDF Downloads 14
7712 Language Teachers Exercising Agency Amid Educational Constraints: An Overview of the Literature

Authors: Anna Sanczyk

Abstract:

Teacher agency plays a crucial role in effective teaching, supporting diverse students, and providing an enriching learning environment; therefore, it is significant to gain a deeper understanding of language teachers’ sense of agency in teaching linguistically and culturally diverse students. This paper presents an overview of qualitative research on how language teachers exercise their agency in diverse classrooms. The analysis of the literature reveals that language teachers strive for addressing students’ needs and challenging educational inequalities, but experience educational constraints in enacting their agency. The examination of the research on language teacher agency identifies four major areas where language teachers experience challenges in enacting their agency: (1) implementing curriculum; (2) adopting school reforms and policies; (3) engaging in professional learning; (4) and negotiating various identities as professionals. The practical contribution of this literature review is that it provides a much-needed compilation of the studies on how language teachers exercise agency amid educational constraints. The discussion of the overview points to the importance of teacher identity, learner advocacy, and continuous professional learning and the critical need of promoting empowerment, activism, and transformation in language teacher education. The findings of the overview indicate that language teacher education programs should prepare teachers to be active advocates for English language learners and guide teachers to become more conscious of complexities of teaching in constrained educational settings so that they can become agentic professionals. This literature overview illustrates agency work in English language teaching contexts and contributes to understanding of the important link between experiencing educational constraints and development of teacher agency.

Keywords: advocacy, educational constraints, language teacher agency, language teacher education

Procedia PDF Downloads 177
7711 The Challenges of Cloud Computing Adoption in Nigeria

Authors: Chapman Eze Nnadozie

Abstract:

Cloud computing, a technology that is made possible through virtualization within networks represents a shift from the traditional ownership of infrastructure and other resources by distinct organization to a more scalable pattern in which computer resources are rented online to organizations on either as a pay-as-you-use basis or by subscription. In other words, cloud computing entails the renting of computing resources (such as storage space, memory, servers, applications, networks, etc.) by a third party to its clients on a pay-as-go basis. It is a new innovative technology that is globally embraced because of its renowned benefits, profound of which is its cost effectiveness on the part of organizations engaged with its services. In Nigeria, the services are provided either directly to companies mostly by the key IT players such as Microsoft, IBM, and Google; or in partnership with some other players such as Infoware, Descasio, and Sunnet. This action enables organizations to rent IT resources on a pay-as-you-go basis thereby salvaging them from wastages accruable on acquisition and maintenance of IT resources such as ownership of a separate data centre. This paper intends to appraise the challenges of cloud computing adoption in Nigeria, bearing in mind the country’s peculiarities’ in terms of infrastructural development. The methodologies used in this paper include the use of research questionnaires, formulated hypothesis, and the testing of the formulated hypothesis. The major findings of this paper include the fact that there are some addressable challenges to the adoption of cloud computing in Nigeria. Furthermore, the country will gain significantly if the challenges especially in the area of infrastructural development are well addressed. This is because the research established the fact that there are significant gains derivable by the adoption of cloud computing by organizations in Nigeria. However, these challenges can be overturned by concerted efforts in the part of government and other stakeholders.

Keywords: cloud computing, data centre, infrastructure, it resources, virtualization

Procedia PDF Downloads 351
7710 Application of Simulation of Discrete Events in Resource Management of Massive Concreting

Authors: Mohammad Amin Hamedirad, Seyed Javad Vaziri Kang Olyaei

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Project planning and control are one of the most critical issues in the management of construction projects. Traditional methods of project planning and control, such as the critical path method or Gantt chart, are not widely used for planning projects with discrete and repetitive activities, and one of the problems of project managers is planning the implementation process and optimal allocation of its resources. Massive concreting projects is also a project with discrete and repetitive activities. This study uses the concept of simulating discrete events to manage resources, which includes finding the optimal number of resources considering various limitations such as limitations of machinery, equipment, human resources and even technical, time and implementation limitations using analysis of resource consumption rate, project completion time and critical points analysis of the implementation process. For this purpose, the concept of discrete-event simulation has been used to model different stages of implementation. After reviewing the various scenarios, the optimal number of allocations for each resource is finally determined to reach the maximum utilization rate and also to reduce the project completion time or reduce its cost according to the existing constraints. The results showed that with the optimal allocation of resources, the project completion time could be reduced by 90%, and the resulting costs can be reduced by up to 49%. Thus, allocating the optimal number of project resources using this method will reduce its time and cost.

Keywords: simulation, massive concreting, discrete event simulation, resource management

Procedia PDF Downloads 148
7709 Effects of Achillea millefolium L. Extract on Rat Spermatogenesis

Authors: Nasrin Takzaree, Gholamreza Hassanzadeh, Abbas Hadjiakhoondi, Mohammadreza Rouini

Abstract:

Introduction: Today herbal medicine are extensively used for various therapeutic reasons. Whereas Achillea millefolium L. comprises different chemical compounds it is used in classic and modern medicine for different purposes. Concerning the family planning as a principle matter, the idea of using specific herbal medicine is of great importance. Purpose: To investigate the effects of Achillea millefolium L. extract on fertility power and spermatogenesis process in male mature Wistar rats and the anti-fertility effects of this extract in male genital system. Material and methods: In this study 32 male mature Wistar rats were randomly divided in to 4 experimental groups. 1st experimental group included 8 rats receiving Achillea millefolium extract at the dose of 200 mg/kg intraperitoneally. Second and third groups received the extract the same at the doses of 400 and 800 mg/kg respectively. 4th group was considered as control group in which the parenteral distilled water was administered. after 20 days, rats were sacrificed and the spermatogenesis process was histologically examined. Results: In experimental groups receiving high doses of extract comparing with control group, thickness in seminiferous tubules basal membrane, decrease in germinal epithelium cells, congestion in testicular tissue, disarrangement in germinal epithelium cells as well as decrease in cellular condense were observed (p<0.001). Conclusion: Findings suggest that alcoholic extract of Achillea millefolium at high concentrations lead to the structural alterations and changes in spermatogenesis in testicular tissue.

Keywords: spermatogenesis, alcoholic extract of Achillea millefolium L., testis, Wistar rat

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7708 Vibration Damping Properties of Electrorheological Materials Based on Chitosan/Perlite Composite

Authors: M. Cabuk, M. Yavuz, T. A. Yesil, H. I. Unal

Abstract:

Electrorheological (ER) fluids are a class of smart materials exhibiting reversible changes in their rheological and mechanical properties under an applied electric field (E). ER fluids generally are composed of polarisable solid particles dispersed in non-conducting oil. ER fluids are fluids which exhibit. The resistance to motion of the ER fluid can be controlled by adjusting the applied E, due to their fast and reversible changes in their rheological properties presence of E. In this study, a series of chitosan/expanded perlite (CS/EP) composites with different chitosan mass fractions (10%, 20%, and 50%) was used. Characterizations of the composites were carried out by Fourier Transform Infrared (FTIR), X-ray diffraction (XRD) and Scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX) techniques. Antisedimentation stability and dielectric properties of the composites were also determined. The effects of volume fraction, electric field strength, shear rate, shear stress, and temperature onto ER properties of the CS/EP composite particles dispersed in silicone oil (SO) were investigated in detail. Vibration damping behavior of the CS/EP composites were determined as a function of frequence, storage (Gʹ) and loss (Gʹ ʹ) moduli. It was observed that ER response of the CS/EP/SO ER fluids increased with increasing electric field strength and exhibited the typical shear thinning non-Newtonian viscoelastic behaviors with increasing shear rate. The maximum yield stress was obtained with 1250 Pa under E = 3 kV/mm. Further, the CS/EP/SO ER fluids were observed to sensitive to vibration control by showing reversible viscosity enhancements (Gʹ > Gʹ ʹ). Acknowledgements: The authors thank the TÜBİTAK (214Z199) for the financial support of this work.

Keywords: chitosan, electrorheology, perlite, vibration control

Procedia PDF Downloads 236
7707 The Development of a Low Carbon Cementitious Material Produced from Cement, Ground Granulated Blast Furnace Slag and High Calcium Fly Ash

Authors: Ali Shubbar, Hassnen M. Jafer, Anmar Dulaimi, William Atherton, Ali Al-Rifaie

Abstract:

This research represents experimental work for investigation of the influence of utilising Ground Granulated Blast Furnace Slag (GGBS) and High Calcium Fly Ash (HCFA) as a partial replacement for Ordinary Portland Cement (OPC) and produce a low carbon cementitious material with comparable compressive strength to OPC. Firstly, GGBS was used as a partial replacement to OPC to produce a binary blended cementitious material (BBCM); the replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of OPC. The optimum BBCM was mixed with HCFA to produce a ternary blended cementitious material (TBCM). The replacements were 0, 10, 15, 20, 25, 30, 35, 40, 45 and 50% by the dry mass of BBCM. The compressive strength at ages of 7 and 28 days was utilised for assessing the performance of the test specimens in comparison to the reference mixture using 100% OPC as a binder. The results showed that the optimum BBCM was the mix produced from 25% GGBS and 75% OPC with compressive strength of 32.2 MPa at the age of 28 days. In addition, the results of the TBCM have shown that the addition of 10, 15, 20 and 25% of HCFA to the optimum BBCM improved the compressive strength by 22.7, 11.3, 5.2 and 2.1% respectively at 28 days. However, the replacement of optimum BBCM with more than 25% HCFA have showed a gradual drop in the compressive strength in comparison to the control mix. TBCM with 25% HCFA was considered to be the optimum as it showed better compressive strength than the control mix and at the same time reduced the amount of cement to 56%. Reducing the cement content to 56% will contribute to decrease the cost of construction materials, provide better compressive strength and also reduce the CO2 emissions into the atmosphere.

Keywords: cementitious material, compressive strength, GGBS, HCFA, OPC

Procedia PDF Downloads 194