Search results for: production methods

Authors: Ibrahim Sengor, Sumeyye Cesur, Ilyas Kartal, Faik Nuzhet Oktar, Nazmi Ekren, Ahmet Talat Inan, Oguzhan Gunduz

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In recent years, many researchers focused on nano-size fiber production. Nanofibers have been studied due to their different and superior physical, chemical and mechanical properties. Poly (lactic acid) (PLA), is a type of biodegradable thermoplastic polyester derived from renewable sources used in biomedical owing to its biocompatibility and biodegradability. In addition, zinc oxide is an antibacterial material and hazelnut shell powder is a filling material. In this study, nanofibers were obtained by adding of different ratio Zinc oxide, (ZnO) and hazelnut shell powder at different concentration into Poly (lactic acid) (PLA) by using electrospinning method which is the most common method to obtain nanofibers. After dissolving the granulated polylactic acids in % 1,% 2,% 3 and% 4 with chloroform solvent, they are homogenized by adding tween and hazelnut shell powder at different ratios and then by electrospinning, nanofibers are obtained. Scanning electron microscope (SEM), Fourier transform infrared spectroscopy (FTIR), Differential scanning calorimeter (DSC) and physical analysis such as density, electrical conductivity, surface tension, viscosity measurement and antimicrobial test were carried out after production process. The resulting structures of the nanofiber possess antimicrobial and antiseptic properties, which are attractive for biomedical applications. The resulting structures of the nanofiber possess antimicrobial, non toxic, self-cleaning and rigid properties, which are attractive for biomedical applications.

Keywords: electrospinning, hazelnut shell powder, nanofibers, poly (lactic acid), zinc oxide

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Authors: M. Torres, A. Moulay, M. Zhuldybina, M. Rozel, N. D. Trinh, C. Bois

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Printed electronics are a fast-growing market as their applications cover a large range of industrial needs, their production cost is low, and the additive printing techniques consume less materials than subtractive manufacturing methods used in traditional electronics. With the growing demand for printed electronics, there are concerns about their harmful and irreversible contribution to the environment. Indeed, it is estimated that 80% of the environmental load of a product is determined by the choices made at the conception stage. Therefore, examination through a life cycle approach at the developing stage of a novel product is the best way to identify potential environmental issues and make proactive decisions. Life cycle analysis (LCA) is a comprehensive scientific method to assess the environmental impacts of a product in its different stages of life: extraction of raw materials, manufacture and distribution, use, and end-of-life. Impacts and major hotspots are identified and evaluated through a broad range of environmental impact categories of the ReCiPe (H) middle point method. At the conception stage, the LCA is a tool that provides an environmental point of view on the choice of materials and processes and weights-in on the balance between performance materials and eco-friendly materials. Using the life cycle approach, the current work aims to provide a cradle-to-grave life cycle assessment of a roll-to-roll hybrid printed smart label designed for the food cold chain. Furthermore, this presentation will present the environmental impact of metallic conductive inks, a comparison with promising conductive polymers, evaluation of energy vs. performance of industrial printing processes, a full assessment of the impact from the smart label applied on a cellulosic-based substrate during the recycling process and the possible recovery of precious metals and rare earth elements.

Keywords: Eco-design, label, life cycle assessment, printed electronics

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Authors: Florin Leon, Silvia Curteanu

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Developing complete mechanistic models for polymerization reactors is not easy, because complex reactions occur simultaneously; there is a large number of kinetic parameters involved and sometimes the chemical and physical phenomena for mixtures involving polymers are poorly understood. To overcome these difficulties, empirical models based on sampled data can be used instead, namely regression methods typical of machine learning field. They have the ability to learn the trends of a process without any knowledge about its particular physical and chemical laws. Therefore, they are useful for modeling complex processes, such as the free radical polymerization of methyl methacrylate achieved in a batch bulk process. The goal is to generate accurate predictions of monomer conversion, numerical average molecular weight and gravimetrical average molecular weight. This process is associated with non-linear gel and glass effects. For this purpose, an adaptive sampling technique is presented, which can select more samples around the regions where the values have a higher variation. Several machine learning methods are used for the modeling and their performance is compared: support vector machines, k-nearest neighbor, k-nearest neighbor and random forest, as well as an original algorithm, large margin nearest neighbor regression. The suggested method provides very good results compared to the other well-known regression algorithms.

Keywords: batch bulk methyl methacrylate polymerization, adaptive sampling, machine learning, large margin nearest neighbor regression

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Authors: Tania Vazquez, Aida Huerta

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Way to get our food has changed over the time, and it is a daily necessity. Nowadays we found a lot of problems involved with the economy, environment, and society, which affect the agrifood system. Some problems as construction of big cities and growing population have been increasing demand food directly. Due to the countryside are far away from the city, another alternative systems have come from, such as Urban Agriculture (UA). UA system offers food production into the cities, products with characteristics as quality, healthy and good prices, close to the customers, recycling culture and the promote environmental education. Last years in Mexico City urban gardens have taken strongly in various politic delegations. There are establishment’s public and private initiatives. Moreover, these places have had different issues like low income, many activities, few workers, low production, lack of training and advice, devaluation of your work and low sales, all these shortcomings generate the devaluation of their work. The aim of this paper is to evaluate a business plan in Mexico City´s urban gardens that contribute to ensuring economic, environmental and social sustainability; to adjust business plan for this places so that they reach viability over time. As a part of soft systems methodology developed of Peter Checkland, we interviewed owners of urban gardens and we found that recurring problem was lack planning manager activities and a master plan about their business. We evaluate the business plan based on “Ten principles in sustainable food value chain development” proposed for Food and Agriculture Organization of the United Nations (FAO). With this study was possible measure, understand and improve performance of business plan in the three pillars of the sustainability in addition to this it allowed us to fit in with the needs of urban gardens.

Keywords: business plan, Mexico City, urban agriculture, urban gardens

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Authors: Saddam Hussain, Ghadeer Mohsen Albadrani

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Pakistan is one of the most vulnerable countries to climate change. Being a country where 23% of the country’s GDP relies on agriculture, this is a serious cause of concern. Introducing industrial hemp in Pakistan can help build climate resilience in the agricultural sector of the country, as hemp has recently emerged as a sustainable, eco-friendly, resource-efficient, and climate-resilient crop globally. Hemp has the potential to absorb huge amounts of CO₂, nourish the soil, and be used to create various biodegradable and eco-friendly products. Hemp is twice as effective as trees at absorbing and locking up carbon, with 1 hectare (2.5 acres) of hemp reckoned to absorb 8 to 22 tonnes of CO₂ a year, more than any woodland. Along with its high carbon-sequestration ability, it produces higher biomass and can be successfully grown as a cover crop. Hemp can grow in almost all soil conditions and does not require pesticides. It has fast-growing qualities and needs only 120 days to be ready for harvest. Compared with cotton, hemp requires 50% less water to grow and can produce three times higher fiber yield with a lower ecological footprint. Recently, the Government of Pakistan has allowed the cultivation of industrial hemp for industrial and medicinal purposes, making it possible for hemp to be reinserted into the country’s economy. Pakistan’s agro-climatic and edaphic conditions are well-suitable to produce industrial hemp, and its cultivation can bring economic benefits to the country. Pakistan can enter global markets as a new exporter of hemp products. The production of hemp in Pakistan can be most exciting to the workforce, especially for farmers participating in hemp markets. The minimum production cost of hemp makes it affordable to small holding farmers, especially those who need their cropping system to be as highly sustainable as possible. Dr. Saddam Hussain is leading the first pilot project of Industrial Hemp in Pakistan. In the past three years, he has been able to recruit high-impact research grants on industrial hemp as Principal Investigator. He has already screened the non-toxic hemp genotypes, tested the adaptability of exotic material in various agroecological conditions, formulated the production agronomy, and successfully developed the complete value chain. He has developed prototypes (fabric, denim, knitwear) using hemp fibre in collaboration with industrial partners and has optimized the indigenous fibre processing techniques. In this lecture, Dr. Hussain will talk on hemp agronomy and its complete fibre value chain. He will discuss the current progress, and will highlight the major challenges and future research direction on hemp research.

Keywords: industrial hemp, agricultural sustainability, agronomic evaluation, hemp value chain

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Authors: Neritan Shkodrani, Klearta Rrushi, Anxhela Shaha

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Generally, the design of axial load capacity of deep foundations is based on the data provided from field tests, such as SPT (Standard Penetration Test) and CPT (Cone Penetration Test) tests. This paper reports the results of axial load capacity analysis of drilled shafts at a construction site at Semani, in Fier county, Fier prefecture in Albania. In this case, the axial load capacity analyses are based on the data of 416 SPT tests and 12 CPTU tests, which are carried out in this site construction using 12 boreholes (10 borings of a depth 30.0 m and 2 borings of a depth of 80.0m). The considered foundation widths range from 0.5m to 2.5 m and foundation embedment lengths is fixed at a value of 25m. SPT – based analytical methods from the Japanese practice of design (Building Standard Law of Japan) and CPT – based analytical Eslami and Fellenius methods are used for obtaining axial ultimate load capacity of drilled shafts. The considered drilled shaft (25m long and 0.5m - 2.5m in diameter) is analyzed for the soil conditions of each borehole. The values obtained from sets of calculations are shown in different charts. Then the reported axial load capacity values acquired from SPT and CPTU data are compared and some conclusions are found related to the mentioned methods of calculations.

Keywords: deep foundations, drilled shafts, axial load capacity, ultimate load capacity, allowable load capacity, SPT test, CPTU test

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Authors: Giorgia Carratta

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Since the beginning of mass production, plastic items have been crucial in our daily lives. Thanks to their physical and chemical properties, plastic materials have proven almost irreplaceable in a number of economic sectors such as packaging, automotive, building and construction, textile, and many others. At the same time, the disruptive consequences of plastic pollution have been progressively brought to light in all environmental compartments. The overaccumulation of plastics in the environment, and its adverse effects on habitats, wildlife, and (most likely) human health, represents a call for action to decision-makers around the globe. From a regulatory perspective, plastic production is an unprecedented challenge at all levels of governance. At the international level, the design of new legal instruments, the amendment of existing ones, and the coordination among the several relevant policy areas requires considerable effort. Under the pressure of both increasing scientific evidence and a concerned public opinion, countries seem to slowly move towards the discussion of a new international ‘plastic treaty.’ However, whether, how, and with which scopes such instrument would be adopted is still to be seen. Additionally, governments are establishing regional-basedstrategies, prone to consider the specificities of the plastic issue in a certain geographical area. Thanks to the new Circular Economy Action Plan, approved in March 2020 by the European Commission, EU countries are slowly but steadily shifting to a carbon neutral, circular economy in the attempt to reduce the pressure on natural resources and, parallelly, facilitate sustainable economic growth. In this context, the EU Plastic Strategy is promising to change the way plastic is designed, produced, used, and treated after consumption. In fact, only in the EU27 Member States, almost 26 million tons of plastic waste are generated herein every year, whose 24,9% is still destined to landfill. Positive effects of the Strategy also include a more effective protection of our environment, especially the marine one, the reduction of greenhouse gas emissions, a reduced need for imported fossil energy sources, more sustainable production and consumption patterns. As promising as it may sound, the road ahead is still long. The need to implement these measures in domestic legislations makes their outcome difficult to predict at the moment. An analysis of the current international and European Union legal framework on plastic pollution, binding, and voluntary instruments included, could serve to detect ‘blind spots’ in the current governance as well as to facilitate the development of policy interventions along the plastic value chain, where it appears more needed.

Keywords: environmental law, European union, governance, plastic pollution, sustainability

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Authors: Ratih Julistina, M. Agoes Moelyadi

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Innovation in aviation technology evolved rapidly by time to time for acquiring the most favorable value of utilization and is usually denoted by efficiency parameter. Nature always become part of inspiration, and for this sector, many researchers focused on studying the behavior of flying animal to comprehend the fundamental, one of them is birds. Experimental testing has already conducted by several researches to seek and calculate the efficiency by putting the object in wind tunnel. Hence, computational simulation is needed to conform the result and give more visualization which is based on Reynold Averaged Navier-Stokes equation solution for unsteady case in time-dependent viscous flow. By creating model from simplification of the real bird as a rigid body, those are Hawk which has low aspect ratio and Swift with high aspect ratio, subsequently generating the multi grid structured mesh to capture and calculate the aerodynamic behavior and characteristics. Mimicking the motion of downstroke and upstroke of bird flight which produced both lift and thrust, the sinusoidal function is used. Simulation is carried out for varied of flapping frequencies within upper and lower range of actual each bird’s frequency which are 1 Hz, 2.87 Hz, 5 Hz for Hawk and 5 Hz, 8.9 Hz, 13 Hz for Swift to investigate the dependency of frequency effecting the efficiency of aerodynamic characteristics production. Also, by comparing the result in different condition flights with the morphology of each bird. Simulation has shown that higher flapping frequency is used then greater aerodynamic coefficient is obtained, on other hand, efficiency on thrust production is not the same. The result is analyzed from velocity and pressure contours, mesh movement as to see the behavior.

Keywords: characteristics of aerodynamic, efficiency, flapping frequency, flapping wing, unsteady simulation

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Authors: Radegunda Kessy, Justus Ochieng, Victor Afari-Sefa, Takemore Chagomoka, Ngoni Nenguwo

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Vegetables are excellent sources of dietary fiber, vitamins, and minerals which constitute an indispensable constituent of diets, but in Tanzania and other Sub-Saharan African countries, they are not readily available all year round due to seasonal variations in the production cycle. Drying of vegetables is one of the traditional methods for food preservation known to man. The Dodoma and Singida regions of Tanzania are characterized by semi-arid agro-climate, thereby experiencing short seasonal supply of fresh vegetables followed by long drought in which dried vegetables become an alternative to meet high household demands. A primary survey of 244 of rural consumers was carried out to understand how knowledge, attitudes, and perceptions of rural consumers affect consumption of dried vegetables. The sample respondents were all found to be aware of open sun drying of vegetables while less than 50% of them were aware of solar-dried vegetables. Consumers were highly concerned with the hygiene, nutritional values, taste, drying method, freshness, color of dried vegetables, timely availability and easiness of cooking as important factors they consider before they purchase dried vegetables. Logit model results show that gender, income, years of consuming dried vegetables, awareness of the importance of solar dried vegetables vis-à-vis sun-dried alternatives and employment status influenced rural consumer’s decision to purchase dried vegetables. Preference on dried vegetables differs across the regions which are also important considerations for any future planned interventions. The findings imply that development partners and policymakers need to design better social marketing and promotion techniques for the enhanced adoption of solar drying technology, which will greatly improve the quality and utilization of dried vegetables by target households.

Keywords: dried vegetables, postharvest management, sun drying, solar drying

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Authors: Walelgn Dilnesa Cherie, Fasikaw Atanaw Zimale, Bekalu W. Asres

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The most catastrophic condition for agricultural production is a drought event, which is also one of the most hydro-metrological-related hazards. According to the combined susceptibility of plants to meteorological and hydrological conditions, agricultural drought is defined as the magnitude, severity, and duration of a drought that affects crop production. The accurate and timely assessment of agricultural drought can lead to the development of risk management strategies, appropriate proactive mechanisms for the protection of farmers, and the improvement of food security. The evaluation of agricultural drought in the East Gojjam zone was the primary subject of this study. To identify the agricultural drought, soil moisture anomalies, soil moisture deficit indices, and Normalized Difference Vegetation Indices (NDVI) are used. The measured welting point, field capacity, and soil moisture were utilized to validate the soil water deficit indices computed from the satellite data. The soil moisture and soil water deficit indices in 2013 in all woredas were minimum; this makes vegetation stress also in all woredas. The soil moisture content decreased in 2013/2014/2019, and 2021 in Dejen, 2014, and 2019 in Awobel Woreda. The max/ min values of NDVI in 2013 are minimum; it dominantly shows vegetation stress and an observed agricultural drought that happened in all woredas. The validation process of satellite and in-situ soil moisture and soil water deficit indices shows a good agreement with a value of R²=0.87 and 0.56, respectively. The study area becomes drought detected region, so government officials, policymakers, and environmentalists pay attention to the protection of drought effects.

Keywords: NDVI, agricultural drought, SWDI, soil moisture

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Authors: Yulin Liang

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Under the background of protecting ecology, natural education is an effective way for people to understand nature. At the same time, it is a new means of sustainable development of eco-tourism, which can improve the functions of China 's protected areas and develop new business formats for the development of national parks. This study takes national park gateway communities as the research object and uses literature review, inductive reasoning and other research methods to sort out the development process of natural education in China and the research progress of natural education design in national park gateway communities. Finally, it discuss how gateway communities can use natural education to transform their development methods and provide theoretical and practical basis for the development of gateway communities in national parks.

Keywords: nature education, gateway communities, national park, sustainable development

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Authors: Elma C. Sultan

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The study concentrated on Vernacular Language Origin and Students’ Accent Neutralization of the College of Arts and Sciences fourth students in Samar State University, Catbalogan City answering respondent’s locale profile, vernacular language origin in terms of local dialect/s and domestic language/s used; the significant relationship between vernacular language origin and accent neutralization of the respondents; and the proposed activities to adopt in neutralizing students’ accent. It utilized the descriptive-correlational method of research determining the significant relationship between vernacular language origin and students’ accent neutralization. The researcher used: (1) questionnaire divided into three parts: the first part identified the students’ locale; the second part determined the respondents’ domestic language/s used while the third part identified their local language/s used, (2) validated accent neutralization assessment tool, (3) statistical treatments in the analysis of data: percentage to determine the profile of the students; chi-square test for independence to determine the significant relationship between vernacular language origin and students’ accent neutralization. Findings of the study showed that vowel and diphthong sound production, domestic and local languages in indigenous, and native dialects are significantly related to accent neutralization. While, slow reading speed has a higher possibility in affecting accent neutralization. These caused designing a 50-hour short-term program for accent neutralization focusing in the correct vowel and diphthong sounds production and appropriate reading speed in preparation for the respondents’ search for BPO employment. This short-term program ran for 5 hours in a day for five days in a week.

Keywords: accent neutralization, dialect, diphthongs, indigenous, language origin, language, native, reading speed, vernacular, vowels

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Authors: Daniela Velichová

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Plenty of ideas on how to adopt active learning methods in education are available nowadays. Mathematics is a subject where the active involvement of students is required in particular in order to achieve desirable results regarding sustainable knowledge and deep understanding. The present article is based on the outcomes of an Erasmus+ project DrIVE-MATH, that was aimed at developing a novel and integrated framework to teach maths classes in engineering courses at the university level. It is fundamental for students from the early years of their academic life to have agile minds. They must be prepared to adapt to their future working environments, where enterprises’ views are always evolving, where all collaborate in teams, and relations between peers are thought for the well-being of the whole - workers and company profit. This reality imposes new requirements on higher education in terms of adaptation of different pedagogical methods, such as project-based and active-learning methods used within the course curricula. Active learning methodologies are regarded as an effective way to prepare students to meet the challenges posed by enterprises and to help them in building critical thinking, analytic reasoning, and insight to the solved complex problems from different perspectives. Fostering learning-by-doing activities in the pedagogical process can help students to achieve learning independence, as they could acquire deeper conceptual understanding by experimenting with the abstract concept in a more interesting, useful, and meaningful way. Clear information about learning outcomes and goals might help students to take more responsibility for their learning results. Active learning methods implemented by the project team members in their teaching practice, eduScrum and Jigsaw in particular, proved to provide better scientific and soft skills support to students than classical teaching methods. EduScrum method enables teachers to generate a working environment that stimulates students' working habits and self-initiative as they become aware of their responsibilities within the team, their own acquired knowledge, and their abilities to solve problems independently, though in collaboration with other team members. This method enhances collaborative learning, as students are working in teams towards a common goal - knowledge acquisition, while they are interacting with each other and evaluated individually. Teams consisting of 4-5 students work together on a list of problems - sprint; each member is responsible for solving one of them, while the group leader – a master, is responsible for the whole team. A similar principle is behind the Jigsaw technique, where the classroom activity makes students dependent on each other to succeed. Students are divided into groups, and assignments are split into pieces, which need to be assembled by the whole group to complete the (Jigsaw) puzzle. In this paper, analysis of students’ perceptions concerning the achievement of deeper conceptual understanding in mathematics and the development of soft skills, such as self-motivation, critical thinking, flexibility, leadership, responsibility, teamwork, negotiation, and conflict management, is presented. Some new challenges are discussed as brought by introducing active learning methods in the basic mathematics courses. A few examples of sprints developed and used in teaching basic maths courses at technical universities are presented in addition.

Keywords: active learning methods, collaborative learning, conceptual understanding, eduScrum, Jigsaw, soft skills

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Authors: Zerihun Yohannes Amare, Belayneh Birku Geremew, Nigatu Melise Kebede, Sisaynew Getahun Amera

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In Ethiopia, agricultural production is predominantly rainfed. The El Niño Southern Oscillation (ENSO) is the driver of climate variability, which affects the agricultural production system in the country. This paper aims to study trends, variability of rainfall, and impacts of El Niño Southern Oscillation (ENSO) on rainfall amount. The study was carried out in Ethiopia's Western Amhara National Regional State, which features a variety of seasons that characterize the nation. Monthly rainfall data were collected from fifteen meteorological stations of Western Amhara. Selected El Niño and La Niña years were also extracted from National Oceanic and Atmospheric Administration (NOAA) from 1986 to 2015. Once the data quality was checked and inspected, the monthly rainfall data of the selected stations were arranged in Microsoft Excel Spreadsheet and analyzed using XLSTAT software. The coefficient of variation and the Mann-Kendall non-parametric statistical test was employed to analyze trends and variability of rainfall and temperature. The long-term recorded annual rainfall data indicated that there was an increasing trend from 1986 to 2015 insignificantly. The rainfall variability was less (Coefficient of Variation, CV = 8.6%); also, the mean monthly rainfall of Western Amhara decreased during El Niño years and increased during La Niña years, especially in the rainy season (JJAS) over 30 years. This finding will be useful to suggest possible adaptation strategies and efficient use of resources during planning and implementation.

Keywords: rainfall, Mann-Kendall test, El Niño, La Niña, Western Amhara, Ethiopia

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Authors: Zinhle Cindi, Collet Dandara, Mpiko Ntsekhe, Edson Makambwa, Miguel Larceda

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Background: Warfarin is the most commonly used drug in the management of thromboembolic disease. However, there is a huge variability in the time, number of doses or starting doses for patients to achieve the required international normalised ratio (INR) which is compounded by a narrow therapeutic index. Many genetic-association studies have reported on European and Asian populations which have led to the designing of specific algorithms that are now being used to assist in warfarin dosing. However, very few or no studies have looked at the pharmacogenetics of warfarin in African populations, yet, huge differences in dosage requirements to reach the same INR have been observed. Objective: We set out to investigate the distribution of 3 SNPs CYP4F2 c.1347C > T, VKORC1 g.-1639G > A and VKORC1 c.1173C > T among South African Mixed Ancestry (MA) and Black African patients. Methods: DNA was extracted from 383 participants and subsequently genotyped using PCR/RFLP for the CYP4F2 c.1347 (V433M) (rs2108622), VKORC1 g.-1639 (rs9923231) and VKORC1 c.1173 (rs9934438) SNPs. Results: Comparing the Black and MA groups, significant differences were observed in the distribution of the following genotypes; CYP4F2 c.1347C/T (23% vs. 39% p=0.03). All VKORC1 g.-1639G > A genotypes (p < 0.006) and all VKORC1 c.1173C > T genotypes (p < 0.007). Conclusion: CYP4F2 c.1347T (V433M) reduces CYP4F2 protein levels and therefore expected to affect the amount of warfarin needed to block vitamin k recycling. The VKORC1 g-1639A variant alters transcriptional regulation therefore affecting the function of vitamin k epoxide reductase in vitamin k production. The VKORC1 c.1173T variant reduces the enzyme activity of VKORC1 consequently enhancing the effectiveness of warfarin. These are preliminary results; more genetic characterization is required to understand all the genetic determinants affecting how patients respond to warfarin.

Keywords: algorithms, pharmacogenetics, thromboembolic disease, warfarin

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Authors: L. Correia-Sá, S. Norberto, Conceição Calhau, C. Delerue-Matos, V. F. Domingues

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Endocrine disruptor chemicals (EDCs) are synthetic compounds that even though being initially designed for a specific function are now being linked with a wide range of side effects. The list of possible EDCs is growing and includes phthalates and bisphenol A (BPA). Phthalates are one of the most widely used plasticizers to improve the extensibility, elasticity and workability of polyvinyl chloride (PVC), polyvinyl acetates, etc. Considered non-toxic and harmless additives for polymers, they were used unrestrainedly all over the world for several decades. However, recent studies have indicated that some phthalates and their metabolic products are reproductive and developmental toxicants in animals and suspected endocrine disruptors in humans. BPA (2,2-bis(4-hydroxyphenyl)propane) is a high production volume chemical mainly used in the production of polycarbonate plastics and epoxy resins. Although BPA was initially considered to be a weak environmental estrogen, nowadays it is known that this compound can stimulate several cellular responses at very low levels of concentrations. The aim of this study was to develop a method based on tandem SPE to evaluate the presence of phthalates, metabolites and BPA in human urine samples. The analyzed compounds included: dibutyl phthalate (DBP) and di-2-ethylhexyl phthalate (DEHP), BPA, mono-isobutyl phthalate (MiBP), monobutyl phthalate (MBP) and. mono-(2-ethyl-5-oxohexyl) (MEOHP). Two SPE cartridges were applied both from Phenomenex, the strata X polymeric reversed phase and the strata X A (Strong anion). Chromatographic analyses were carried out in a Thermo GC ULTRA GC-MS/MS. Good recoveries and linear calibration curves were obtained. After validation, the methodology was applied to human urine samples for phthalates, metabolites and BPA evaluation.

Keywords: Bisphenol A (BPA), gas chromatography, metabolites, phtalates, SPE, tandem mode

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Authors: Assia Belfar, Mohamed Hadjadj, Messaouda Dakmouche, Zineb Ghiaba

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Introduction: This study aims to phytochemical screening; Extracting the active compounds and estimate the effectiveness of antioxidant in Medicinal plants desert Limoniastrum guyonianum (Zeïta) from South Algeria. Methods: Total phenolic content and total flavonoid content using Folin-Ciocalteu and aluminum chloride colorimetric methods, respectively. The total antioxidant capacity was estimated by the following methods: DPPH (1.1-diphenyl-2-picrylhydrazyl radical) and reducing power assay. Results: Phytochemical screening of the plant part reveals the presence of phenols, saponins, flavonoids and tannins. While alkaloids and Terpenoids were absent. The acetonic extract of L. guyonianum was extracted successively with ethyl acetate and butanol. Extraction of yield varied widely in the L. guyonianum ranging from (0.9425 %to 11.131%). The total phenolic content ranged from 53.33 mg GAE/g DW to 672.79 mg GAE/g DW. The total flavonoid concentrations varied from 5.45 to 21.71 mg/100g. IC50 values ranged from 0.02 ± 0.0004 to 0.13 ± 0.002 mg/ml. All extracts showed very good activity of ferric reducing power, the higher power was in butanol fraction (23.91 mM) more effective than BHA, BHT and VC. Conclusions: Demonstrated this study that the acetonic extract of L. guyonianum contain a considerable quantity of phenolic compounds and possess a good antioxidant activity. Can be used as an easily accessible source of Natural Antioxidants and as a possible food supplement and in the pharmaceutical industry.

Keywords: limoniastrum guyonianum, phenolics compounds, flavonoid compound, antioxidant activity

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Authors: Michael Kenomore, Mohamed Hassan, Amjad Shah, Hom Dhakal

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Shale gas reservoirs have been of greater importance compared to shale oil reservoirs since 2009 and with the current nature of the oil market, understanding the technical and economic performance of shale gas reservoirs is of importance. Using the Barnett shale as a case study, an economic model was developed to quantify the effect of finding and development costs and gas prices on the basins in the Barnett shale using net present value as an evaluation parameter. A rate of return of 20% and a payback period of 60 months or less was used as the investment hurdle in the model. The Barnett was split into four basins (Strawn Basin, Ouachita Folded Belt, Forth-worth Syncline and Bend-arch Basin) with analysis conducted on each of the basin to provide a holistic outlook. The dataset consisted of only horizontal wells that started production from 2008 to at most 2015 with 1835 wells coming from the strawn basin, 137 wells from the Ouachita folded belt, 55 wells from the bend-arch basin and 724 wells from the forth-worth syncline. The data was analyzed initially on Microsoft Excel to determine the estimated ultimate recoverable (EUR). The range of EUR from each basin were loaded in the Palisade Risk software and a log normal distribution typical of Barnett shale wells was fitted to the dataset. Monte Carlo simulation was then carried out over a 1000 iterations to obtain a cumulative distribution plot showing the probabilistic distribution of EUR for each basin. From the cumulative distribution plot, the P10, P50 and P90 EUR values for each basin were used in the economic model. Gas production from an individual well with a EUR similar to the calculated EUR was chosen and rescaled to fit the calculated EUR values for each basin at the respective percentiles i.e. P10, P50 and P90. The rescaled production was entered into the economic model to determine the effect of the finding and development cost and gas price on the net present value (10% discount rate/year) as well as also determine the scenario that satisfied the proposed investment hurdle. The finding and development costs used in this paper (assumed to consist only of the drilling and completion costs) were £1 million, £2 million and £4 million while the gas price was varied from $2/MCF-$13/MCF based on Henry Hub spot prices from 2008-2015. One of the major findings in this study was that wells in the bend-arch basin were least economic, higher gas prices are needed in basins containing non-core counties and 90% of the Barnet shale wells were not economic at all finding and development costs irrespective of the gas price in all the basins. This study helps to determine the percentage of wells that are economic at different range of costs and gas prices, determine the basins that are most economic and the wells that satisfy the investment hurdle.

Keywords: shale gas, Barnett shale, unconventional gas, estimated ultimate recoverable

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Authors: Nhabhat Chaimongkol

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Human capital is one of the factors that are vital for economic growth. This is especially true as humans will face increasingly more forms of disruptive technology in the near future. Therefore, there is a need to develop human capital in order to overcome the current uncertainty in the global economy and the future of jobs. In recent years, Thailand has increasingly devoted more attention to developing its human capital. The Thai government has raised this issue in its national agenda, which is part of its 20-year national strategy. Currently, there are multiple challenges and solutions regarding this issue. This study aims to find out what are the challenges and solutions to human capital development in Thailand. The research in this study uses mixed methods consisting of quantitative and qualitative research methods. The results show that while Thailand has many plans to develop human capital, it is still lacking the necessary actions and integrations that are required to achieve its goals. Finally, the challenges and solutions will be discussed in detail.

Keywords: challenges, human capital, solutions, Thailand

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Authors: Bong Jae Lee, Jeong Il Lee, Hyo Su Kim

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Both developed and developing countries have adopted the decision to join the Paris agreement to reduce greenhouse gas (GHG) emissions at the Conference of the Parties (COP) 21 meeting in Paris. As a result, the developed and developing countries have to submit the Intended Nationally Determined Contributions (INDC) by 2020, and each country will be assessed for their performance in reducing GHG. After that, they shall propose a reduction target which is higher than the previous target every five years. Therefore, an accurate method for calculating greenhouse gas emissions is essential to be presented as a rational for implementing GHG reduction measures based on the reduction targets. Non-CO2 GHGs (CF4, NF3, N2O, SF6 and so on) are being widely used in fabrication process of semiconductor manufacturing, and etching/deposition process of display manufacturing process. The Global Warming Potential (GWP) value of Non-CO2 is much higher than CO2, which means it will have greater effect on a global warming than CO2. Therefore, GHG calculation methods of the electronics industry are provided by Intergovernmental Panel on climate change (IPCC) and U.S. Environmental Protection Agency (EPA), and it will be discussed at ISO/TC 146 meeting. As discussed earlier, being precise and accurate in calculating Non-CO2 GHG is becoming more important. Thus this study aims to discuss the implications of the calculating methods through comparing the methods of IPCC and EPA. As a conclusion, after analyzing the methods of IPCC & EPA, the method of EPA is more detailed and it also provides the calculation for N2O. In case of the default emission factor (by IPCC & EPA), IPCC provides more conservative results compared to that of EPA; The factor of IPCC was developed for calculating a national GHG emission, while the factor of EPA was specifically developed for the U.S. which means it must have been developed to address the environmental issue of the US. The semiconductor factory ‘A’ measured F gas according to the EPA Destruction and Removal Efficiency (DRE) protocol and estimated their own DRE, and it was observed that their emission factor shows higher DRE compared to default DRE factor of IPCC and EPA Therefore, each country can improve their GHG emission calculation by developing its own emission factor (if possible) at the time of reporting Nationally Determined Contributions (NDC). Acknowledgements: This work was supported by the Korea Evaluation Institute of Industrial Technology (No. 10053589).

Keywords: non-CO2 GHG, GHG emission, electronics industry, measuring method

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Authors: Marta Fonseca, Pedro Marvão, Beatriz Oliveira, Bruno Heleno, Pedro Carreiro-Martins, Nuno Neuparth, António Rendas

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Background: Concept maps (CMs) visually represent hierarchical connections among related ideas. They foster logical organization and clarify idea relationships, potentially aiding medical students in critical thinking (to think clearly and rationally about what to do or what to believe). However, there are inconsistent claims about the use of CMs in undergraduate medical education. Our three research questions are: 1) What studies have been published on concept mapping in undergraduate medical education? 2) What was the impact of CMs on students’ critical thinking? 3) How and why have these interventions had an educational impact? Methods: Eight databases were systematically searched (plus a manual and an additional search were conducted). After eliminating duplicate entries, titles, and abstracts, and full-texts were independently screened by two authors. Data extraction and quality assessment of the studies were independently performed by two authors. Qualitative and quantitative data were integrated using mixed-methods. The results were reported using the structured approach to the reporting in healthcare education of evidence synthesis statement and BEME guidance. Results: Thirty-nine studies were included from 26 journals (19 quantitative, 8 qualitative and 12 mixed-methods studies). CMs were considered as a tool to promote critical thinking, both in the perception of students and tutors, as well as in assessing students’ knowledge and/or skills. In addition to their role as facilitators of knowledge integration and critical thinking, CMs were considered both teaching and learning methods. Conclusions: CMs are teaching and learning tools which seem to help medical students develop critical thinking. This is due to the flexibility of the tool as a facilitator of knowledge integration, as a learning and teaching method. The wide range of contexts, purposes, and variations in how CMs and instruments to assess critical thinking are used increase our confidence that the positive effects are consistent.

Keywords: concept map, medical education, undergraduate, critical thinking, meaningful learning

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Authors: Cajethan U. Ugwuoke

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Agriculture is taught in secondary schools to develop skills in students which will empower them to contribute to national economic development. Unfortunately, our educational system emphasizes the application of conventional teaching methods in delivering instructions, which fails to produce students competent enough to carry out agricultural production. This study was therefore aimed at examining the application of digital technologies as tools for transformative instructional delivery. Four specific purposes, research questions and hypotheses guided the study. The study adopted a descriptive survey research design where 80 subjects representing 64 teachers of agriculture and 16 principals in the Udenu local government area of Enugu State, Nigeria, participated in the study. A structured questionnaire was used to collect data. The assumption of normality was ascertained by subjecting the data collected to a normality test. Data collected were later subjected to mean, Pearson product-moment correlation, ANOVA and t-test to answer the research questions and test the hypotheses at a 5% significant level. The result shows that the application of digital technologies helps to reduce learners’ boredom (3.52.75), improves learners’ performance (3.63.51), and is used as a visual aid for learners (3.56.61), among others. There was a positive, strong and significant relationship between the application of digital technologies and effective instructional delivery (+.895, p=.001<.05, F=17.73), competency of teachers to the application of digital technologies and effective instructional delivery (+998, p=.001<0.5, F=16263.45), and frequency of the application of digital technologies and effective instructional delivery (+.999, p=.001<.05, F=31436.14). There was no evidence of autocorrelation and multicollinearity in the regression models between the application of digital technologies and effective instructional delivery (2.03, Tolerance=1.00, VIF=1.00), competency of teachers in the application of digital technologies and effective instructional delivery (2.38, Tolerance=1.00, VIF=1.00) and frequency of the application of digital technologies and effective instructional delivery (2.00, Tolerance=1.00, VIF=1.00). Digital technologies should be therefore applied in teaching to facilitate effective instructional delivery in agriculture.

Keywords: agricultural science, digital technologies, instructional delivery, learning

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Authors: M. Sazali Said, Rahim Jamian, Shahrizan Yusoff, Shahruzaman Sulaiman, Jum'Azulhisham Abdul Shukor

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This case study focuses on the role of Universiti Kuala Lumpur Malaysian Spanish Institute (UniKL MSI) to produce technologist in order to reduce the shortage of skilled workers especially in the automotive industry. The purpose of the study therefore seeks to examine the effectiveness of Technical Education and Vocational Training (TEVT) curriculum of UniKL MSI to produce graduates that could immediately be productively employed by the automotive industry. The approach used in this study is through performance evaluation of students attending the Industrial Training Attachment (INTRA). The sample of study comprises of 37 students, 16 university supervisors and 26 industrial supervisors. The research methodology involves the use of quantitative and qualitative methods of data collections through the triangulation approach. The quantitative data was gathered from the students, university supervisors and industrial supervisors through the use of questionnaire. Meanwhile, the qualitative data was obtained from the students and university supervisors through the use of interview and observation. Both types of data have been processed and analyzed in order to summarize the results in terms of frequency and percentage by using a computerized spread sheet. The result shows that industrial supervisors were satisfied with the students’ performance. Meanwhile, university supervisors rated moderate effectiveness of the UniKL MSI curriculum in producing graduates with appropriate skills and in meeting the industrial needs. During the period of study, several weaknesses in the curriculum have been identified for further continuous improvements. Recommendations and suggestions for curriculum improvement also include the enhancement of technical skills and competences of students towards fulfilling the needs and demand of the automotive industries.

Keywords: technical education and vocational training (TEVT), industrial training attachment (INTRA), curriculum improvement, automotive industry

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Authors: Tripti Nayak, R. K. Bajpai

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An ongoing field experiment was conducted at Long term fertilizer experiment, Raipur, to study the Effect of fertilization (both organic and inorganic) on soil Physical properties (infiltration rate) of Vertisol of ten treatments viz. The treatment combinations for were T1(Control),T2(50%NPK), T3(100%NPK), T4(150%NPK), T5(100%NPK+Zn), T6(100%NP), T7(100%N), T8(100%NPK+FYM), T9 (50%NPK+BGA) and T10(50%NPK+GM). Farmyard manure and green manure is applied at the treatment of T8 (100%NPK+FYM) and T10 (50%NPK+GM). Result showed that the highest infiltration rate recorded T8(100%NPK+FYM) and T10 (50%NPK+GM). These considerations have led to a renewed interest in the organic manures such as FYM, compost and green manures, which are formulations helps in sustainable agriculture production either by providing plants with fixed nitrogen, available P or by other plant growth promoting substances. Organic matter (OM) is the life of the soil because it contains all the essential elements required for plant growth. It also serves as food for soil bacteria. Decomposed OM, known as humus, improves the soil tilth, quality and helps the plant to grow. In general among all the other treatments and control gave poorest infiltration rate. Incorporation of organic sources considerably improved the soil physical properties such as decrease in bulk density and increase in infiltration rate and available NPK status of the soil. Study showed that wherever, nitrogen was substituted through GM, FYM or crop residue (rice straw) in rice, Corresponding decrease in bulk density favorably enhanced the infiltration rate and it was found to be highest in the green-manured plot, FYM and lowest in control. Concluded that Continuous monitoring of physical properties should be carried out for maintaining soil health and enhancing the crop production.

Keywords: long term effect, FYM, green manure, infiltration rate, soil health, crop productivity, vertisol

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Authors: Wen-Chyan Tsai, Syed S. H. Rizvi

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Organic solvent residues are always associated with liposomes produced by the traditional techniques like the thin film hydration and reverse phase evaporation methods, which limit the applications of these vesicles in the pharmaceutical, food and cosmetic industries. Our objective was to develop a novel and benign process of liposomal microencapsulation by using supercritical carbon dioxide (SC-CO2) as the sole phospholipid-dissolving medium and a green substitute for organic solvents. This process consists of supercritical fluid extraction followed by rapid expansion via a nozzle and automatic cargo suction. Lecithin and cholesterol mixed in 10:1 mass ratio were dissolved in SC-CO2 at 20 ± 0.5 MPa and 60 oC. After at least two hours of equilibrium, the lecithin/cholesterol-laden SC-CO2 was passed through a 1000-micron nozzle and immediately mixed with the cargo solution to form liposomes. Liposomal micro-encapsulation was conducted at three pressures (8.27, 12.41, 16.55 MPa), three temperatures (75, 83 and 90 oC) and two flow rates (0.25 ml/sec and 0.5 ml/sec). Liposome size, zeta potential and encapsulation efficiency were characterized as functions of the operating parameters. The average liposomal size varied from 400-500 nm to 1000-1200 nm when the pressure was increased from 8.27 to 16.55 MPa. At 12.41 MPa, 90 oC and 0.25 ml per second of 0.2 M glucose cargo loading rate, the highest encapsulation efficiency of 31.65 % was achieved. Under a confocal laser scanning microscope, large unilamellar vesicles and multivesicular vesicles were observed to make up a majority of the liposomal emulsion. This new approach is a rapid and continuous process for bulk production of liposomes using a green solvent. Based on the results to date, it is feasible to apply this technique to encapsulate hydrophilic compounds inside the aqueous core as well as lipophilic compounds in the phospholipid bilayers of the liposomes for controlled release, solubility improvement and targeted therapy of bioactive compounds.

Keywords: liposome, micro encapsulation, supercritical carbon dioxide, non-toxic process

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Authors: G. R. Hashemi Tabar, G. R. Razmi, F. Mirshekar

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Echinococcus granulosus have ten strains from G1 to G9. Each strain is related to special intermediated host. The morphology, epidemiology, treatment and control in these strains are different. There are many morphological and molecular methods to differentiate of Echinococcus strains. However, using both methods were provided better information about identification of each strain. The aim of study was to identify Echinococcus granulosus strain of hydrated cysts in slaughtered sheep using morphological and molecular methods in Mashhad area. In the present study, the infected liver and lung with hydatid cysts were collected and transferred to laboratory. The hydatid cyst liquid was extracted and morphological characters of rostellar hook protosclocies were measured using micrometer ocular. The total length of large blade length of large hooks, total length of small and blade length of small hooks, and number of hooks per protoscolex were 23± 0.3μm, 11.7±0.5 μm, 19.3±1.1 μm,8±1.1 and 33.7±0.7 μm, respectively. In molecular section of the study, DNA each samples was extracted with MBST Kit and development of PCR using special primers (EgF, EgR) which amplify fragment of ITS1 gen. The PCR product was digested with Bsh1236I enzyme. Based on pattern of PCR-RLFP results (four band forming), G1, G2 and G3 strain of Echinococcus granulosus were obtained. Differentiation of three strains was done using sequencing analysis and G1 strain was diagnosed. The agreement between the molecular results with morphometric characters of rosetellar hook was confirmed the presence of G1 strain of Echinococcus in the slaughtered sheep of Mashhad area.

Keywords: Echinococcus granulosus, Hydatid cyst, PCR, sheep

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Authors: Alban Igwe, Ijeoma Kalu, Alloy Ezirim

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Food insecurity is a global problem, and the search for food security has assumed a central stage in the global development agenda as the United Nations currently placed zero hunger as a goal number in its sustainable development goals. Nigeria currently ranks 107th out of 113 countries in the global food security index (GFSI), a metric that defines a country's ability to furnish its citizens with food and nutrients for healthy living. Paradoxically, Nigeria is a global leader in food production, ranking 1st in yam (over 70% of global output), beans (over 41% of global output), cassava (20% of global output) and shea nuts, where it commands 53% of global output. Furthermore, it ranks 2nd in millet, sweet potatoes, and cashew nuts. It is Africa's largest producer of rice. So, it is apparent that Nigeria's food insecurity woes must relate to a factor other than food production. We investigated the nexus between food security and downstream supply chain losses in the yam industry with secondary data from the Food and Agricultural Organization (FAOSTAT) and the National Bureau of Statics for the decade 2012-2021. In analyzing the data, multiple regression techniques were used, and findings reveal that downstream losses have a strong positive correlation with food security (r = .763*) and a 58.3% variation in food security is explainable by post-downstream supply chain food losses. The study discovered that yam supply chain losses within the period under review averaged 50.6%, suggestive of the fact that downstream supply chain losses are the drainpipe and the major source of food insecurity in Nigeria. Therefore, the study concluded that there is a significant relationship between downstream supply chain losses and food insecurity and recommended the establishment of food supply chain structures and policies to enhance food security in Nigeria.

Keywords: food security, downstream supply chain losses, yam, nigeria, supply chain

Procedia PDF Downloads 80

Authors: Sophia Anastasiou, Cosmas Nathanailides, Fotini Kakali, Panagiotis Logothetis, Gregorios Kanlis

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The method and rearing conditions of aquaculture may very between different regions and aquaculture sites. Globally, the Aquaculture industry faces a challenge to develop aquaculture methods which safeguard the economic viability of the company, the welfare of farmed fish and final product quality and sustainable development of aquaculture. Marine fish farms in Greece operate in different locations and farmed fish are exposed to a variety of rearing conditions. This paper investigates the variability of product quality and the financial performance of different marine fish farms operating in West Greece. Production parameters of gilthead sea bream fish farm such as feeding regimes, mortalities, fish densities were used to calculate the economic efficiency of six different aquaculture sites from West Greece. Samples of farmed sea bream were collected and lipid content, microbial load and filleting yield of the samples were used as quality criteria. The results indicate that Lipid content, filleting yield and microbial load of fish originating from different fish farms varied significantly with improved quality exhibited in fish farms which exhibited improved Feed conversion rates and lower mortalities. Changes in feeding management practices such as feed quality and feeding regimes have a significant impact on the financial performance of sea bass farms. Fish farms which exhibited improved feeding conversion rates also exhibited increased profitability. Improvements in the FCR explained about 13.4 % of the difference in profitability of the different aquaculture sites. Lower mortality and higher growth rates were also exhibited by the fish farms which exhibited improved FCR. It is concluded that best feeding management practices resulted in improved product quality and profitability.

Keywords: fish quality, aquaculture management, feeding management, profitability

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Authors: Ekaterina Lukianchenko

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This article sums up a six-year experience of teaching English as a foreign language to over 900 university students at MGIMO (Moscow University of International Relations, Russia), all of them native speakers of Russian aged 16 to 23. By combining modern communicative approach to teaching with cognitive linguistics theories, one can deal more effectively with deeply rooted mistakes which particular students have of which conventional methods have failed to eliminate. If language items are understood as concepts and frames, and classroom activities as meaningful parts of language competence development, this might help to solve such problems as incorrect use of words, unsuitable register, and confused tenses - as well as logical or structural mistakes, and even certain psychological issues concerning essay writing. Along with classic teaching methods, such classroom practice includes plenty of interaction between students - playing special classroom games aimed at eliminating particular mistakes, working in pairs and groups, integrating all skills in one class. The main conclusions that the author of the experiment makes consist in an assumption that academic essay writing classes demand a balanced plan. This should not only include writing as such, but additionally feature elements of listening, reading, speaking activities specifically chosen according to the skills and language students will need to write the particular type of essay.

Keywords: academic essay writing, creative teaching, cognitive linguistics, competency-based approach, communicative language teaching, frame, concept

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Authors: Gabriella Dravecz, László Péter, Zsolt Kis

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Abstract— The growth of optical LiNbO3 single crystal and its physical and chemical properties are well known on the macroscopic scale. Nowadays the rare-earth doped single crystals became important for coherent quantum optical experiments: electromagnetically induced transparency, slow down of light pulses, coherent quantum memory. The expansion of applications is increasingly requiring the production of nano scaled LiNbO3 particles. For example, rare-earth doped nanoscaled particles of lithium niobate can be act like single photon source which can be the bases of a coding system of the quantum computer providing complete inaccessibility to strangers. The polyol method is a chemical synthesis where oxide formation occurs instead of hydroxide because of the high temperature. Moreover the polyol medium limits the growth and agglomeration of the grains producing particles with the diameter of 30-200 nm. In this work nano scaled LiNbO3 was prepared by the polyol method. The starting materials (niobium oxalate and LiOH) were diluted in H2O2. Then it was suspended in ethylene glycol and heated up to about the boiling point of the mixture with intensive stirring. After the thermal equilibrium was reached, the mixture was kept in this temperature for 4 hours. The suspension was cooled overnight. The mixture was centrifuged and the particles were filtered. Dynamic Light Scattering (DLS) measurement was carried out and the size of the particles were found to be 80-100 nms. This was confirmed by Scanning Electron Microscope (SEM) investigations. The element analysis of SEM showed large amount of Nb in the sample. The production of LiNbO3 nano particles were succesful by the polyol method. The agglomeration of the particles were avoided and the size of 80-100nm could be reached.

Keywords: lithium-niobate, nanoparticles, polyol, SEM

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