Search results for: quality properties

Authors: Dawoon Choi, Jian Li, Yunhyun Cho

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Axial Flux Permanent Magnet (AFPM) machines have been widely used in various applications due to their important merits, such as compact structure, high efficiency and high torque density. This paper presents one of the most important characteristics in the design process of the AFPM device, which is a recent issue. To design AFPM machine, the predicting electromagnetic forces between the permanent magnets and stator is important. Because of the magnitude of electromagnetic force affects many characteristics such as machine size, noise, vibration, and quality of output power. Theoretically, this force is canceled by the equilibrium of force when it is in the middle of the gap, but it is inevitable to deviate due to manufacturing problems in actual machine. Such as large scale wind generator, because of the huge attractive force between rotor and stator disks, this is more serious in getting large power applications such as large. This paper represents the characteristics of Double-Stator Inner –Rotor AFPM machines when it has rotor eccentricity. And, unbalanced air-gap and inclined air-gap condition which is caused by rotor offset and tilt in a double-stator single inner-rotor AFPM machine are each studied in electromagnetic and mechanical aspects. The output voltage and cogging torque under un-normal air-gap condition of AF machines are firstly calculated using a combined analytical and numerical methods, followed by a structure analysis to study the effect to mechanical stress, deformation and bending forces on bearings. Results and conclusions given in this paper are instructive for the successful development of AFPM machines.

Keywords: axial flux permanent magnet machine, inclined air gap, unbalanced air gap, rotor eccentricity

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Authors: Shah Fahad

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Managing the Urban Heat Island (UHI) effects is a pressing concern for achieving sustainable urban development and ensuring thermal comfort in major cities of developing nations, such as Lahore, Pakistan. The current UHI effect is mostly triggered by climate change and rapid urbanization. This study explored UHI over the Lahore district and its adjoining urban and rural-urban fringe areas. Landsat satellite data was utilized to investigate spatiotemporal patterns of Land Use and Land Cover changes (LULC), Land Surface Temperature (LST), UHI, Normalized Difference Built-up Index (NDBI), Normalized Difference Vegetation Index (NDVI), and Urban Thermal Field Variance Index (UTFVI). The built-up area increased very fast, with a coverage of 22.99% in 2000, 36.06% in 2010, and 47.17% in 2020, while vegetation covered 53.21 % in 2000 and 46.16 % in 2020. It also revealed a significant increase in the mean LST, from 33°C in 2000 to 34.8°C in 2020. The results indicated a significantly positive correlation between LST and NDBI, a weak correlation was also observed between LST and NDVI. The study used scatterplots to show the correlation between NDBI and NDVI with LST, results revealed that the NDBI and LST had an R² value of 0.6831 in 2000 and 0.06541 in 2022, while NDVI and LST had an R² value of 0.0235 in 1998 and 0.0295 in 2022. Proper environmental planning is vital in specific locations to enhance quality of life, protect the ecosystem, and mitigate climate change impacts.

Keywords: land use land cover, spatio-temporal analysis, remote sensing, land surface temperature, urban heat island, lahore pakistan

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Authors: Syeda Fahria Hoque Mimmi

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Many new and promising treatments for reducing or diminishing the adverse effects of microorganisms are being discovered day by day. On the other hand, the dairy industry is accelerating the economic wheel of Bangladesh. Considering all these facts, new thoughts were developed to isolate milk proteins by the present experiment for opening up a new era of developing natural antibiotics from milk. Lactoferrin, an iron-binding glycoprotein with multifunctional properties, is crucial to strengthening the immune system and also useful for commercial applications. The protein’s iron-binding capacity makes it undoubtedly advantageous to immune system modulation and different bacterial strains. For fulfilling the purpose, 4 of raw and 17 of commercially available milk samples were collected from different farms and stores in Bangladesh (Dhaka, Chittagong, and Cox’s Bazar). Protein quantification by nanodrop technology has confirmed that raw milk samples have better quantities of protein than the commercial ones. All the samples were tested for their antimicrobial activity against 18 pathogens, where raw milk samples showed a higher percentage of antibacterial activity. In addition to this, SDS-PAGE (Sodium Dodecyl Sulfate–Polyacrylamide Gel Electrophoresis) was performed to identify lactoferrin in the milk samples. Lactoferrin was detected in 9 samples from which 4 were raw milk samples. Interestingly, Streptococcus pyogenes, Klebsiella pneumoniae, Bacillus cereus, Pseudomonas aeruginosa, Vibrio cholera, Staphylococcus aureus, and enterotoxigenic E. coli significantly displayed sensitivity against lactoferrin collected from raw milk. Only Bacillus cereus, Pseudomonas aeruginosa, Streptococcus pneumonia, Enterococcus faecalis, and ETEC (Enterotoxigenic Escherichia coli) were susceptible to lactoferrin obtained from a commercial one. This study suggested that lactoferrin might be used as the potential alternative of antibiotics for many diseases and also can be used to reduce microbial deterioration in the food and feed industry.

Keywords: alternative of antibiotics, commercially available milk, lactoferrin, nanodrop technology, pathogens, raw milk

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Authors: Roman Graf, Sergiu Gordea, Heather M. Ryan

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This paper presents an approach for the easy creation of an institutional risk profile for endangerment analysis of file formats. The main contribution of this work is the employment of data mining techniques to support risk factors set up with just the most important values that are important for a particular organisation. Subsequently, the risk profile employs fuzzy models and associated configurations for the file format metadata aggregator to support digital preservation experts with a semi-automatic estimation of endangerment level for file formats. Our goal is to make use of a domain expert knowledge base aggregated from a digital preservation survey in order to detect preservation risks for a particular institution. Another contribution is support for visualisation and analysis of risk factors for a requried dimension. The proposed methods improve the visibility of risk factor information and the quality of a digital preservation process. The presented approach is meant to facilitate decision making for the preservation of digital content in libraries and archives using domain expert knowledge and automatically aggregated file format metadata from linked open data sources. To facilitate decision-making, the aggregated information about the risk factors is presented as a multidimensional vector. The goal is to visualise particular dimensions of this vector for analysis by an expert. The sample risk profile calculation and the visualisation of some risk factor dimensions is presented in the evaluation section.

Keywords: digital information management, file format, endangerment analysis, fuzzy models

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Authors: Innocent O. Arukalam, Emeka E. Oguzie

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Interest in the development of eco-friendly anti-corrosion coatings using bio-based renewable materials is gaining momentum recently. To this effect, chitin biopolymer, which is non-toxic, biodegradable, and inherently possesses anti-microbial property, was successfully synthesized from snail shells and used as a filler in the preparation of epoxy coating. The chitin particles were characterized with contact angle goniometer, scanning electron microscope (SEM), Fourier transform infrared (FTIR) spectrophotometer, and X-ray diffractometer (XRD). The performance of the coatings was evaluated by immersion and electrochemical impedance spectroscopy (EIS) tests. Electronic structure properties of the coating ingredients and molecular level interaction of the corrodent and coated Q235 steel were appraised by quantum chemical computations (QCC) and molecular dynamics (MD) simulation techniques, respectively. The water contact angle (WCA) measurement of chitin particles was found to be 129.3o while that of chitin particles modified with amino trimethoxy silane (ATMS) was 149.6o, suggesting it is highly hydrophobic. Immersion and EIS analyses revealed that epoxy coating containing silane-modified chitin exhibited lowest water absorption and highest barrier as well as anti-corrosion performances. The QCC showed that quantum parameters for the coating containing silane-modified chitin are optimum and therefore corresponds to high corrosion protection. The high negative value of adsorption energies (Eads) for the coating containing silane-modified chitin indicates the coating molecules interacted and adsorbed strongly on the steel surface. The observed results have shown that silane-modified epoxy-chitin coating would perform satisfactorily for surface protection of metal structures in saline environment.

Keywords: chitin, EIS, epoxy coating, hydrophobic, molecular dynamics simulation, quantum chemical computation

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Authors: Dalal Sadeqi

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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

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Authors: Dongguk Im, Gunfeel Moon, Younwoo Nam, Kangwoo Chun

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Recognition of the needs about protecting environment throughout worldwide is widespread. In the shipping industry, International Maritime Organization (IMO) has been regulating pollutants emitted from ships by MARPOL 73/78. Recently, the Marine Environment Protection Committee (MEPC) of IMO, at its 68th session, approved the definition of Black Carbon (BC) specified by the following physical properties (light absorption, refractory, insolubility and morphology). The committee also agreed to the need for a protocol for any voluntary measurement studies to identify the most appropriate measurement methods. Filter Smoke Number (FSN) based on light absorption is categorized as one of the IMO relevant BC measurement methods. EUROMOT provided a FSN measurement data (measured by smoke meter) of 31 different engines (low, medium and high speed marine engines) of member companies at the 3rd International Council on Clean Transportation (ICCT) workshop on marine BC. From the comparison of FSN, the results indicated that BC emission from low speed marine diesel engines was ranged from 0.009 to 0.179 FSN and it from medium and high speed marine diesel engine was ranged 0.012 to 3.2 FSN. In consideration of measured the low FSN from low speed engine, an experimental study was conducted using both a low speed marine diesel engine (2 stroke, power of 7,400 kW at 129 rpm) and a high speed marine diesel engine (4 stroke, power of 403 kW at 1,800 rpm) under E3 test cycle. The results revealed that FSN was ranged from 0.01 to 0.16 and 1.09 to 1.35 for low and high speed engines, respectively. The measurement equipment (smoke meter) ranges from 0 to 10 FSN. Considering measurement range of it, FSN values from low speed engines are near the detection limit (0.002 FSN or ~0.02 mg/m3). From these results, it seems to be modulated the measurement range of the measurement equipment (smoke meter) for enhancing measurement accuracy of marine BC and evaluation on performance of BC abatement technologies.

Keywords: black carbon, filter smoke number, international maritime organization, marine diesel engine (two and four stroke), particulate matter

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Authors: Jelena Vucicevic

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Reliability analysis represents a very important task in different areas of work. In any industry, this is crucial for maintenance, efficiency, safety and monetary costs. There are ways to calculate reliability, unreliability, failure density and failure rate. In this paper, the results for the reliability of diesel generator fans were calculated through Extreme Value Theory. The Extreme Value Theory is not widely used in the engineering field. Its usage is well known in other areas such as hydrology, meteorology, finance. The significance of this theory is in the fact that unlike the other statistical methods it is focused on rare and extreme values, and not on average. It should be noted that this theory is not designed exclusively for extreme events, but for extreme values in any event. Therefore, this is a great opportunity to apply the theory and test if it could be applied in this situation. The significance of the work is the calculation of time to failure or reliability in a new way, using statistic. Another advantage of this calculation is that there is no need for technical details and it can be implemented in any part for which we need to know the time to fail in order to have appropriate maintenance, but also to maximize usage and minimize costs. In this case, calculations have been made on diesel generator fans but the same principle can be applied to any other part. The data for this paper came from a field engineering study of the time to failure of diesel generator fans. The ultimate goal was to decide whether or not to replace the working fans with a higher quality fan to prevent future failures. The results achieved in this method will show the approximation of time for which the fans will work as they should, and the percentage of probability of fans working more than certain estimated time. Extreme Value Theory can be applied not only for rare and extreme events, but for any event that has values which we can consider as extreme.

Keywords: extreme value theory, lifetime, reliability analysis, statistic, time to failure

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Authors: Jiří F. Urbánek, David Král

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Small and Middle Enterprises (SME) have a specific mission, characteristics, and behavior in global business competitive environments. They must respect policy, rules, requirements and standards in all their inherent and outer processes of supply - customer chains and networks. Paper aims and purposes are to introduce computational assistance, which enables us the using of prevailing operation system MS Office (SmartArt...) for mathematical models, using DYVELOP (Dynamic Vector Logistics of Processes) method. It is providing for SMS´s global environment the capability and profit to achieve its commitment regarding the effectiveness of the quality management system in customer requirements meeting and also the continual improvement of the organization’s and SME´s processes overall performance and efficiency, as well as its societal security via continual planning improvement. DYVELOP model´s maps - the Blazons are able mathematically - graphically express the relationships among entities, actors, and processes, including the discovering and modeling of the cycling cases and their phases. The blazons need live PowerPoint presentation for better comprehension of this paper mission – added value analysis. The crisis management of SMEs is obliged to use the cycles for successful coping of crisis situations.  Several times cycling of these cases is a necessary condition for the encompassment of the both the emergency event and the mitigation of organization´s damages. Uninterrupted and continuous cycling process is a good indicator and controlling actor of SME continuity and its sustainable development advanced possibilities.

Keywords: blazons, computational assistance, DYVELOP method, small and middle enterprises

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Authors: Doostishoar Farzad, Forootanfar Hamid, Hasan-Bikdashti Morvarid, Faramarzi Mohammad Ali, Ameri Atefe

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Introduction: Chili peppers and related plants in the family of capsaicum produce a mixture of capsaicins represent anticarcinogenic, antimutagenic, and chemopreventive properties. Vanillylamine, the main product of capsaicin hydrolysis is applied as a precursor for manufacturing of natural vanillin (a famous flavor). It is also used in the production of synthetic capsaicins harboring a wide variety of physiological and biological activities such as antibacterial and anti-inflammatory effects as well as enhancing of adrenal catecholamine secretion, analgesic, and antioxidative activities. The ability of some lipases, such as Novozym 677 BG and Novozym 435 and also some proteases e.g. trypsine and penicillin acylase, in capsaicin hydrolysis and green synthesis of vanillylamine has been investigated. In the present study the optimized culture broth of a newly isolated lipase-producing bacterial strain (Stenotrophomonas maltophilia) applied for the hydrolysis of capsaicin. Materials and methods: In order to compare hydrolytic activity of optimized and basal culture broth through capsaicin 2 mL of each culture broth (as sources of lipase) was introduced to capsaicin solution (500 mg/L) and then the reaction mixture (total volume of 3 mL) was incubated at 40 °C and 120 rpm. Samples were taken every 2 h and analyzed for vanillylamine formation using HPLC. Same reaction mixture containing boiled supernatant (to inactivate lipase) designed as blank and each experiment was done in triplicate. Results: 215 mg/L of vanillylamine was produced after the treatment of capsaicin using the optimized medium for 18 h, while only 61 mg/L of vanillylamine was detected in presence of the basal medium under the same conditions. No capsaicin conversion was observed in the blank sample, in which lipase activity was suppressed by boiling of the sample for 10 min. Conclusion: The application of optimized broth culture for the hydrolysis of capsaicin led to a 43% conversion of that pungent compound to vanillylamine.

Keywords: Capsaicin, green synthesis, lipase, stenotrophomonas maltophilia

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Authors: Abraham O. Olaniyi, Oluyemi Oke, Atilade Otunla

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The structural performance of bridges decreases progressively throughout their service life due to many contributing factors (fatigue, carbonation, fire incidents etc.). Around the world, numerous bridges have attained their estimated service life and many have approached this limit. The structural integrity assessment of the burnt composite bridge located at CH57+450, Koita village along Abuja-Abaji-Lokoja road, Nigeria, is presented as a case study and shall be forthwith referred to as the 'Koita bridge' in this paper. From the technical evaluation, the residual compressive strength of the concrete piers was found to be below 16.0 N/mm2. This value is very low compared to the expected design value of 30.0 N/mm2. The pier capping beam at pier location 1 has a very low residual compressive strength. The cover to the reinforcement of certain capping beams has an outline of reinforcement which signifies poor concrete cover and the mean compressive strength is also less than 20.0 N/mm2. The steel girder indicated black colouration as a result of the fire incident without any significant structural defect like buckling or warping of the steel section. This paper reviews the structural integrity assessment and repair methodology of the Koita bridge; a composite bridge damaged by fire, highlighting the various challenges of limited obtainable guidance documents about the bridge. The objectives are to increase the understanding of processes and versatile equipment required to test and assess a fire-damaged bridge in order to improve the quality of structural appraisal and rehabilitation; thus, eliminating the prejudice associated with current visual inspection techniques.

Keywords: assessment, bridge, rehabilitation, sustainability

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Authors: S. Nikpour, S. Vahidi, H. Haghani

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Introduction: Exercise has mental and physical health benefits for patients with advanced stage cancer who actively receive chemotherapy, yet little is known about patients’ levels of interest in becoming more active or their confidence in increasing their activity level. Methods and materials: A convenience sample of 200 patients with advanced-stage cancer who were receiving chemotherapy completed self-report measures assessing physical activity level, mood, and quality-of-life variables. Qualitative data on patient-perceived benefits of, and barriers to, physical activity also were collected, coded by independent raters, and organized by predominant themes. Results: Current physical activity level, physical activity outcome expectations, and positive mood were significantly associated with self-efficacy. Fatigue was the most frequently listed barrier to physical activity; improved physical strength and health were the most commonly listed benefits. Participants identified benefits related to both general health and cancer-symptom management that were related to exercise. 59.5% of participants reported that they were seriously planning to increase or maintain their physical activity level, and over 40% reported having interest in receiving an intervention to become more active. Conclusion: These results suggested that many advanced-stage cancer patients who receive chemotherapy are interested in maintaining or increasing their physical activity level and in receiving professional support for exercise. In addition, these individuals identified general health and cancer-specific benefits of, and barriers to, physical activity. Future research will investigate how these findings may be incorporated into physical activity interventions for advanced-stage oncology patients receiving medical treatment.

Keywords: physical activity, cancer, self-efficacy

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Authors: Passant Youssef, Ahmed El-Tair, Amr El-Nemr

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Lately, with the environmental changes, enthusiasts trigger to stop the contamination of environment. Thus, various efforts were exerted for innovating environmental friendly concrete to sustain as a ‘Green Building’ material. Green building materials consider the cement industry as one of the most sources of air pollutant with high rate of carbon dioxide (CO₂) emissions. Several methods were developed to extensively reduce the influence of cement industry on environment. These methods such as using supplementary cementitious material or improving the cement manufacturing process are still under investigation. However, with the presence of recycled wastes from construction and finishing materials, the use of supplementary cementitious materials seems to provide an economic solution. Furthermore, it improves the mechanical properties of cement paste, in addition to; it modulates the workability and durability of concrete. In this paper, the glass powder was considered to be used as partial replacement of cement. This study provided the mechanical influence for using the glass powder as partial replacement of cement. In addition, it examines the microstructure of cement mortar using scanning electron microscope and X-ray diffraction. The cement in concrete is replaced by waste glass powder in steps of 5%, 10%, 15%, 20% and 25% by weight of cement and its effects on compressive and flexure strength were determined after 7 and 28 days. It was found that the 5% glass powder replacement increased the 7 days compressive strength by 20.5%, however, there was no increase in compressive strength after 28 days; which means that the glass powder did not react in the cement mortar due to its amorphous nature on the long run, and it can act as fine aggregate better that cement replacement. As well as, the 5% and 10% glass powder replacement increased the 28 days flexural strength by 46.9%. SEM micrographs showed very dense matrix for the optimum specimen compared to control specimen as well; some glass particles were clearly observed. High counts of silica were optimized from XRD while amorphous materials such as calcium silicate cannot be directly detected.

Keywords: supplementary materials, glass powder, concrete, cementitious materials

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Authors: Mattahias Maj, Fabio Tatzgern, Karl Adam, Damir Kahrimanovic, Markus Varga

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Torpedo ladles are necessary transport carriages in steel production to move the molten crude iron from the blast furnace to the steel refining plant. This requires the ladles to be high temperature resistant and insulate well to preserve the temperature and hold the risk of solidification at bay. Therefore, the involved refractories lining the inside of the torpedo ladles are chosen mostly according to their thermal properties, although wear of the materials by the liquid iron is also of major importance. In this work, we combined investigations of the thermal behaviour with wear studies of the lining over the whole lifetime of a torpedo ladle. Additional numerical simulations enabled a detailed model of the mechanical loads and temperature propagation at the various stations (heating, filling, emptying, cooling). The core of the investigation were detailed 3D measurements of the ladle’s cavity and thereby quantitative information of the wear progress at different time intervals during the lifetime of the ladles. The measurements allowed for a separation of different wear zones according to severity, namely the “splash zone” where the melt directly hits the ladle, the “melt zone” where during transport always liquid melt is present, and the “slag zone”, where the slag floats on the melt causing the most severe wear loss. Numerical simulations of the filling process were taken to calculate stress levels and temperature gradients, which led to the different onset of wear on those zones. Thermal imaging and punctual temperature measurements allowed for a study of the thermal consequences entailed by the wear onset. Additional “classical” damage analysis of the worn refractories complete the investigation. Thereby the wear mechanisms leading to the substantial wear loss were disclosed.

Keywords: high temperature, tribology, liquid-solid interaction, refractories, thermography

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Authors: S. Koul, Joshua Adedamola

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Currently, the global concerning fact about electromagnetic pollution (EMP) is that it not only adversely affects human health but rather projects the malfunctioning of sensitive equipment both locally and at a global level. The market offers many incumbent technologies to solve the issues, but still, a processable sustainable material solution with acceptable limits for GHG emission is still at an exploratory stage. The present work offers a sustainable material solution with a wide range of processability in terms of a polymeric resin matrix and shielding operational efficiency across the electromagnetic spectrum, covering both ionizing and non-ionizing electromagnetic radiations. The present work offers an in-situ synthesized conducting polyaniline (PANI) in the presence of the hybrid dual dopant system with tuned conductivity and high shielding efficiency between 89 to 92 decibels, depending upon the EMI frequency range. The conductive polymer synthesized in the presence of a hybrid dual dopant system via the in-situ emulsion polymerization method offers a higher surface resistance of 1.0 ohms/cm with thermal stability up to 2450C in their powder form. This conductive polymer with a hybrid dual dopant system was used as a filler material with different polymeric thermoplastic resin systems for the preparation of conductive composites. Intrinsically Conductive polymeric (ICP) composites based on hybrid dual dopant systems were prepared using melt blending, extrusion, and finally by, compression molding processing techniques. ICP composites with hybrid dual dopant systems offered good mechanical, thermal, structural, weathering, and stable surface resistivity properties over a period of time. The preliminary shielding behavior for ICP composites between frequency levels of 10 GHz to 24GHZ offered a shielding efficiency of more than 90 dB.

Keywords: ICP, dopant, EMI, shielding

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Authors: Shouji Yujiro, Memei Dukovic, Mist Yakubu

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Fields are important objects of study in algebra since they provide a useful generalization of many number systems, such as the rational numbers, real numbers, and complex numbers. In particular, the usual rules of associativity, commutativity and distributivity hold. Fields also appear in many other areas of mathematics; see the examples below. When abstract algebra was first being developed, the definition of a field usually did not include commutativity of multiplication, and what we today call a field would have been called either a commutative field or a rational domain. In contemporary usage, a field is always commutative. A structure which satisfies all the properties of a field except possibly for commutativity, is today called a division ring ordivision algebra or sometimes a skew field. Also non-commutative field is still widely used. In French, fields are called corps (literally, body), generally regardless of their commutativity. When necessary, a (commutative) field is called corps commutative and a skew field-corps gauche. The German word for body is Körper and this word is used to denote fields; hence the use of the blackboard bold to denote a field. The concept of fields was first (implicitly) used to prove that there is no general formula expressing in terms of radicals the roots of a polynomial with rational coefficients of degree 5 or higher. An extension of a field k is just a field K containing k as a subfield. One distinguishes between extensions having various qualities. For example, an extension K of a field k is called algebraic, if every element of K is a root of some polynomial with coefficients in k. Otherwise, the extension is called transcendental. The aim of Galois Theory is the study of algebraic extensions of a field. Given a field k, various kinds of closures of k may be introduced. For example, the algebraic closure, the separable closure, the cyclic closure et cetera. The idea is always the same: If P is a property of fields, then a P-closure of k is a field K containing k, having property, and which is minimal in the sense that no proper subfield of K that contains k has property P. For example if we take P (K) to be the property ‘every non-constant polynomial f in K[t] has a root in K’, then a P-closure of k is just an algebraic closure of k. In general, if P-closures exist for some property P and field k, they are all isomorphic. However, there is in general no preferable isomorphism between two closures.

Keywords: field theory, mechanic maths, supertech, rolltech

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Authors: Simeon Adebayo Oladipo

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Institutional administrators are currently facing pressure and challenges in their daily operations. Reasons for this may include the increasing multiplicity, uncertainty and tension that permeate institutional leadership. Authentic engagement for institutional leadership is premised on the ethical foundation that the leaders in the schools are engaged. The institutional effectiveness is dependent on the relationship that exists between the leaders and employees in the workplace. Leader’s self-awareness, relational transparency, emotional control, strong moral code and accountability have a positive influence on authentic engagement which variably determines leadership effectiveness. This study therefore examined the role of authentic engagement in effective school leadership; explored the interrelationship of authentic engagement indices in school leadership. The study adopted the descriptive research of the survey type using a quantitative method to gather data through a questionnaire among school leaders in Lagos State Tertiary Institutions. The population for the study consisted of all Heads of Departments, Deans and Principal Officers in Lagos State Tertiary Institutions. A sample size of 255 Heads of Departments, Deans and Principal Officers participated in the study. The data gathered were analyzed using descriptive and inferential statistical tools. The findings indicated that authentic engagement plays a crucial role in increasing leadership effectiveness amongst Heads of Departments, Deans and Principal Officers. The study recommended among others that there is a need for effective measures to enhance authentic engagement of institutional leadership practices through relevant educational support systems and effective quality control.

Keywords: authentic engagement, self-awareness, relational transparency, emotional control

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Authors: Haftu Hailu Berhe, Hailekiros Sibhato Gebremichael, Kinfe Tsegay Beyene, Haileselassie Mehari

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The purpose of the study is to develop and validate integrated literature-based JIT, TQM, TPM, SCM and LSS framework through a combination of the PDCA cycle and DMAIC methodology. The study adopted a mixed research approach. Accordingly, the qualitative study employed to develop the framework is based on identifying the uniqueness and common practices of JIT, TQM, TPM, SCM and LSS initiatives, the existing practice of the integration, identifying the existing gaps in the framework and practices, developing new integrated JIT, TQM, TPM, SCM and LSS practice framework. Previous very few studies of the uniqueness and common practices of the five initiatives are preserved. Whereas the quantitative study working to validate the framework is based on empirical analysis of the self-administered questionnaire using a statistical package for social science. A combination of the PDCA cycle and DMAIC methodology stand integrated CI framework is developed. The proposed framework is constructed as a project-based framework with five detailed implementation phases. Besides, the empirical analysis demonstrated that the proposed framework is valuable if adopted and implemented correctly. So far, there is no study proposed & validated the integrated CI framework within the scope of the study. Therefore, this is the earliest study that proposed and validated the framework for manufacturing industries. The proposed framework is applicable to manufacturing industries and can assist in achieving competitive advantages when the manufacturing industries, institutions and government offer unconditional efforts in implementing the full contents of the framework.

Keywords: integrated continuous improvement framework, just in time, total quality management, total productive maintenance, supply chain management, lean six sigma

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Authors: Nicolas Galazis, Nikolina Docheva, Constantinos Simillis, Kypros Nicolaides

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Background: Obese women are at increased risk for many pregnancy complications, and bariatric surgery (BS) before pregnancy has shown to improve some of these. Objectives: To review the current literature and quantitatively assess the obstetric and neonatal outcomes in pregnant women who have undergone BS. Search Strategy: MEDLINE, EMBASE and Cochrane databases were searched using relevant keywords to identify studies that reported on pregnancy outcomes after BS. Selection Criteria: Pregnancy outcome in firstly, women after BS compared to obese or BMI-matched women with no BS and secondly, women after BS compared to the same or different women before BS. Only observational studies were included. Data Collection and Analysis: Two investigators independently collected data on study characteristics and outcome measures of interest. These were analysed using the random effects model. Heterogeneity was assessed and sensitivity analysis was performed to account for publication bias. Main Results: The entry criteria were fulfilled by 17 non-randomised cohort or case-control studies, including seven with high methodological quality scores. In the BS group, compared to controls, there was a lower incidence of preeclampsia (OR, 0.45, 95% CI, 0.25-0.80; p=0.007), GDM (OR, 0.47, 95% CI, 0.40-0.56; P<0.001) and large neonates (OR 0.46, 95% CI 0.34-0.62; p<0.001) and a higher incidence of small neonates (OR 1.93, 95% CI 1.52-2.44; p<0.001), preterm birth (OR 1.31, 95% CI 1.08-1.58; p=0.006), admission for neonatal intensive care (OR 1.33, 95% CI 1.02-1.72; p=0.03) and maternal anaemia (OR 3.41, 95% CI 1.56-7.44, p=0.002). Conclusions: BS as a whole improves some pregnancy outcomes. Laparoscopic adjustable gastric banding does not appear to increase the rate of small neonates that was seen with other BS procedures. Obese women of childbearing age undergoing BS need to be aware of these outcomes.

Keywords: bariatric surgery, pregnancy, preeclampsia, gestational diabetes, birth weight

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Authors: Adam Y. Sulaiman, Gerard I.Obasi, Roma Chang, Hussein Sayed Moghaieb, Ming J. Huang, Neil J. Hewitt

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Residential air-conditioning units are essential for quality indoor comfort in hot climate countries. Nevertheless, because of their non-renewable energy sources and the contribution of ecologically unfriendly working fluids, these units are a major source of CO2 emissions in these countries. The utilisation of sustainable technologies nowadays is essential to reduce the adverse effects of CO2 emissions by replacing conventional technologies. This paper investigates the feasibility of running an off-grid solar-powered air-conditioning bed unit using three low GWP refrigerants (R32, R290, and R600a) to supersede conventional refrigerants.A prototype air conditioning unit was built to supply cold air to a canopy that was connected to it. The assembled unit was designed to distribute cold air to a canopy connected to it. This system is powered by two 400 W photovoltaic panels, with battery storage supplying power to the unit at night-time. Engineering Equation Solver (EES) software is used to mathematically model the vapor compression cycle (VCC) and predict the unit's energetic and exergetic performance. The TRNSYS software was used to simulate the electricity storage performance of the batteries, whereas the IES-VE was used to determine the amount of solar energy required to power the unit. The article provides an analytical design guideline, as well as a comprehensible process system. Combining a renewable energy source to power an AC based-VCC provides an excellent solution to the real problems of high-energy consumption in warm-climate countries.

Keywords: air-conditioning, refrigerants, PV panel, energy storages, VCC, exergy

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Authors: David Alejandro Lazo-Vasquez, Jorge Luis Balino

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In the petroleum industry, multiphase flow occurs when oil, gas, and water are transported in the same pipe through large pipeline systems. The flow can take different patterns depending on parameters like fluid velocities, pipe diameter, pipe inclination, and fluid properties. Mainly, intermittent flow is produced by the natural propagation of short and long waves, according to the Kelvin-Helmholtz Stability Theory. To model stratified flow and the onset of intermittent flow, it is crucial to have knowledge of short and long waves behavior. The two-fluid model, frequently employed for characterizing multiphase systems, becomes ill-posed for high liquid and gas velocities and large inclination angles, for short waves can develop infinite growth rates. We are interested in focusing attention on long-wave instability, which leads to the production of roll waves that may grow and result in the transition from stratified flow to intermittent flow. In this study, global and local linear stability analyses for dynamic and kinematic stability criteria predict the regions of stability of the flow for different pipe inclinations and fluid velocities in regularized and non-regularized systems, concurrently. It was possible to distinguish when: wave growth rates are absolutely bounded (stable stratified smooth flow), waves have finite growth rates (unstable stratified wavy flow), and when the equation system becomes elliptic and hyperbolization is needed. In order to bound short wave growth rates and regularize the equation system, we incorporated some lower and higher-order terms like interfacial drag and surface tension, respectively.

Keywords: linear stability analysis, multiphase flow, onset of slugging, two-fluid model regularization

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Authors: Mannan Mridha, Mohammad S. Islam

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Innovative medical technologies offer more effective medical care, with less risk to patient and healthcare personnel. Medical technology and devices when properly used provide better data, precise monitoring and less invasive treatments and can be more targeted and often less costly. The Intensive Care Unit (ICU) equipped with patient monitoring, respiratory and cardiac support, pain management, emergency resuscitation and life support devices is particularly prone to medical errors for various reasons. Many people in the developing countries now wonder whether their visit to hospital might harm rather than help them. This is because; clinicians in the developing countries are required to maintain an increasing workload with limited resources and absence of well-functioning safety system. A team of experts from the medical, biomedical and clinical engineering in Sweden and Bangladesh have worked together to study the incidents, adverse events at the ICU in Bangladesh. The study included both public and private hospitals to provide a better understanding for physical structure, organization and practice in operating processes of care, and the occurrence of adverse outcomes the errors, risks and accidents related to medical devices at the ICU, and to develop a ICT based support system in order to reduce hazards and errors and thus improve the quality of performance, care and cost effectiveness at the ICU. Concrete recommendations and guidelines have been made for preparing appropriate ICT related tools and methods for improving the routine for use of medical devices, reporting and analyzing of the incidents at the ICU in order to reduce the number of undetected and unsolved incidents and thus improve the patient safety.

Keywords: intensive care units, medical errors, medical devices, patient care and safety

Procedia PDF Downloads 123

Authors: Abdulraaof H. Alqaili, Hamad A. Alsoliman

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Through progress in pavement design developments, a pavement design method was developed, which is titled the Mechanistic Empirical Pavement Design Guide (MEPDG). Nowadays, the evolution in roads network and highways is observed in Saudi Arabia as a result of increasing in traffic volume. Therefore, the MEPDG currently is implemented for flexible pavement design by the Saudi Ministry of Transportation. Implementation of MEPDG for local pavement design requires the calibration of distress models under the local conditions (traffic, climate, and materials). This paper aims to prepare data for calibration of MEPDG in Central Saudi Arabia. Thus, the first goal is data collection for the design of flexible pavement from the local conditions of the Riyadh region. Since, the modifying of collected data to input data is needed; the main goal of this paper is the analysis of collected data. The data analysis in this paper includes processing each: Trucks Classification, Traffic Growth Factor, Annual Average Daily Truck Traffic (AADTT), Monthly Adjustment Factors (MAFi), Vehicle Class Distribution (VCD), Truck Hourly Distribution Factors, Axle Load Distribution Factors (ALDF), Number of axle types (single, tandem, and tridem) per truck class, cloud cover percent, and road sections selected for the local calibration. Detailed descriptions of input parameters are explained in this paper, which leads to providing of an approach for successful implementation of MEPDG. Local calibration of MEPDG to the conditions of Riyadh region can be performed based on the findings in this paper.

Keywords: mechanistic-empirical pavement design guide (MEPDG), traffic characteristics, materials properties, climate, Riyadh

Procedia PDF Downloads 202

Authors: L. Krpalkova, N. O' Mahony, A. Carvalho, S. Campbell, G. Corkery, E. Broderick, J. Walsh

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Farm management and operations will drastically change due to access to real-time data, real-time forecasting, and tracking of physical items in combination with Internet of Things developments to further automate farm operations. Dairy farms have embraced technological innovations and procured vast amounts of permanent data streams during the past decade; however, the integration of this information to improve the whole farm-based management and decision-making does not exist. It is now imperative to develop a system that can collect, integrate, manage, and analyse on-farm and off-farm data in real-time for practical and relevant environmental and economic actions. The developed systems, based on machine learning and artificial intelligence, need to be connected for useful output, a better understanding of the whole farming issue, and environmental impact. Evolutionary computing can be very effective in finding the optimal combination of sets of some objects and, finally, in strategy determination. The system of the future should be able to manage the dairy farm as well as an experienced dairy farm manager with a team of the best agricultural advisors. All these changes should bring resilience and sustainability to dairy farming as well as improving and maintaining good animal welfare and the quality of dairy products. This review aims to provide an insight into the state-of-the-art of big data applications and evolutionary computing in relation to smart dairy farming and identify the most important research and development challenges to be addressed in the future. Smart dairy farming influences every area of management, and its uptake has become a continuing trend.

Keywords: big data, evolutionary computing, cloud, precision technologies

Procedia PDF Downloads 162

Authors: Faraidoon Rahmanzai, Mizuki Takigawa, Yu Bomura, Shigeyuki Date

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To obtain the high quality and essential workability of mortar, different types of superplasticizers are used. The superplasticizers are the chemical admixture used in the mix to improve the fluidity of mortar. Many factors influenced the superplasticizer to disperse the cement particle in the mortar. Nature and amount of replaced cement by slag, mixing procedure, delayed addition time, and heat stimulation technique of superplasticizer cause the varied effect on the fluidity of the cementitious material. In this experiment, the superplasticizers were heated for 1 hour under 60 °C in a thermostatic chamber. Furthermore, the effect of delayed addition time of heat stimulated superplasticizers (SP) was also analyzed. This method was applied to two types of polycarboxylic acid based ether SP (precast type superplasticizer (SP2) and ready-mix type superplasticizer (SP1)) in combination with a partial replacement of normal Portland cement with blast furnace slag (BFS) with 30% w/c ratio. On the other hands, the fluidity, air content, fresh density, and compressive strength for 7 and 28 days were studied. The results indicate that the addition time and heat stimulation technique improved the flow and air content, decreased the density, and slightly decreased the compressive strength of mortar. Moreover, the slag improved the flow of mortar by increasing the amount of slag, and the effect of external temperature of SP on the flow of mortar was decreased. In comparison, the flow of mortar was improved on 5-minute delay for both kinds of SP, but SP1 has improved the flow in all conditions. Most importantly, the transition points in both types of SP appear to be the same, at about 5±1 min.  In addition, the optimum addition time of SP to mortar should be in this period.

Keywords: combined effect, delay addition, heat stimulation, flow of mortar

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Authors: Bedarnia Ishak

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In the recent years, the dry reforming of methane has received considerable attention from an environmental view point because it consumes and eliminates two gases (CH4 and CO2) responsible for global warming by greenhouse effect. Many catalysts containing noble metal (Rh, Ru, Pd, Pt and Ir) or transition metal (Ni, Co and Fe) have been reported to be active in this reaction. Compared to noble metals, Ni-materials are cheap but very easily deactivated by coking. Ni-based mixed oxides structurally well-defined like perovskites and spinels are being studied because they possibly make solid solutions and allow to vary the composition and thus the performances properties. In this work, nano-sized nickel ferrite oxides are synthesized using three different methods: Co-precipitation (CP), hydrothermal (HT) and sol gel (SG) methods and characterized by XRD, Raman, XPS, BET, TPR, SEM-EDX and TEM-EDX. XRD patterns of all synthesized oxides showed the presence of NiFe2O4 spinel, confirmed by Raman spectroscopy. Hematite was present only in CP sample. Depending on the synthesis method, the surface area, particle size, as well as the surface Ni/Fe atomic ratio (XPS) and the behavior upon reduction varied. The materials were tested in methane dry reforming with CO2 at 1 atm and 650-800 °C. The catalytic activity of the spinel samples was not very high (XCH4 = 5-20 mol% and XCO2 = 25-40 mol %) when no pre-reduction step was carried out. A significant contribution of RWGS explained the low values of H2/CO ratio obtained. The reoxidation step of the catalyst carried out after reaction showed little amounts of coke deposition. The reducing pretreatment was particularly efficient in the case of SG (XCH4 = 80 mol% and XCO2 = 92 mol%, at 800 °C), with H2/CO > 1. In conclusion, the influence of preparation was strong for most samples and the catalytic behavior could be interpreted by considering the distribution of cations among octahedral (Oh) and tetrahedral (Td) sites as in (Ni2+1-xFe3+x) Td (Ni2+xFe3+2-x) OhO2-4 influenced the reducibility of materials and thus their catalytic performance.

Keywords: NiFe2O4, dry reforming of methane, spinel oxide, oxide zenc

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Authors: L. Bammou, M. Belkhaouda R. Salghi, L. Bazzi, B. Hammouti

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Steel and steel-based alloys of different grades steel are extensively used in numerous applications where acid solutions are widely applied such as industrial acid pickling, industrial acid cleaning and oil-well acidizing. The use of chemical inhibitors is one of the most practical methods for the protection against corrosion in acidic media. Most of the excellent acid inhibitors are organic compounds containing nitrogen, oxygen, phosphorus and sulphur. The use of non-toxic inhibitors called green or eco-friendly environmental inhibitors is one of the solutions possible to prevent the corrosion of the material. These advantages have incited us to draw a large part of program of our laboratory to examine natural substances as corrosion inhibitors such as: prickly pear seed oil, Argan oil, Argan extract, Fennel oil, Rosemary oil, Thymus oil, Lavender oil, Jojoba oil, Pennyroyal Mint oil, and Artemisia. In the present work, we investigate the corrosion inhibition of steel in 1 M HCl by junipers extract using weight loss, potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. The result obtained of junipers extract (JE) shows excellent inhibition properties for the corrosion of C38 steel in 1M HCl at 298K, and the inhibition efficiency increases with increasing of the JE concentration. The inhibitor efficiencies determined by weight loss, Tafel polarisation and EIS methods are in reasonable agreement. Based on the polarisation results, the investigated junipers extract can be classified as mixed inhibitor. The calculated structural parameters show increase of the obtained Rct values and decrease of the capacitance, Cdl, with JE concentration increase. It is suggested to attribute this to the increase of the thickness of the adsorption layer at steel surface. The adsorption model obeys to the Langmuir adsorption isotherm. The adsorption process is a spontaneous and exothermic process.

Keywords: corrosion inhibition, steel, friendly inhibitors, Tafel polarisation

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Authors: Marta Czechowska-Bieluga

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Social work education in Poland focuses mostly on developing competencies that address the needs of individuals and families affected by a variety of life's problems. As a result of the ageing of the Polish population, much attention is equally devoted to adults, including the elderly. However, social work with children and young people is the area of education which should be given more consideration. Social work students are mostly trained to cater to the needs of families and the competencies aimed to respond to the needs of children and young people do not receive enough attention and are only offered as elective classes. This paper strives to review the social work programmes offered by the selected higher education institutions in Poland in terms of social work training aimed at helping children and young people to address their life problems. The analysis conducted in this study indicates that university education for social work focuses on training professionals who will provide assistance only to adults. Due to changes in the social and political situation, including, in particular, changes in social policy implemented for the needy, it is necessary to extend this area of education to include the specificity of the support for children and young people; especially, in the light of the appearance of new support professions within the area of social work. For example, family assistants, whose task is to support parents in performing their roles as guardians and educators, also assist children. Therefore, it becomes necessary to equip social work professionals with competencies which include issues related to the quality of life of underage people living in families. Social work curricula should be extended to include the issues of child and young person development and the patterns governing this phase of life.

Keywords: social work education, social work programmes, social worker, university

Procedia PDF Downloads 267

Authors: Yongxin Chen, Min Zhang

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As industrial enterprises are the primary source of national pollution, environmental information disclosure is a crucial way to demonstrate to stakeholders the work they have done in fulfilling their environmental responsibilities and accepting social supervision. In the era of the digital economy, many companies, actively embracing the opportunities that come with digital transformation, have begun to apply digital technology to information collection and disclosure within the enterprise. However, less is known about the relationship between digital transformation and environmental disclosure. This study investigates how enterprise digital transformation affects environmental disclosure in 643 Chinese industrial companies, according to information processing theory. What is intriguing is that the depth (size) and breadth (diversity) of environmental disclosure linearly increase with the rise in the collection, processing, and analytical capabilities in the digital transformation process. However, the volume of data will grow exponentially, leading to a marginal increase in the economic and environmental costs of utilizing, storing, and managing data. In our empirical findings, linearly increasing benefits and marginal costs create a unique inverted U-shaped relationship between the degree of digital transformation and environmental disclosure in the Chinese industrial sector. Besides, based on the upper echelons theory, we also propose that the top management team with high stability and managerial capabilities will invest more effort and expense into improving environmental disclosure quality, lowering the carbon footprint caused by digital technology, maintaining data security etc. In both these contexts, the increasing marginal cost curves would become steeper, weakening the inverted U-shaped slope between DT and ED.

Keywords: digital transformation, environmental disclosure, the top management team, information processing theory, upper echelon theory

Procedia PDF Downloads 105

Authors: Badr Alharbi

Abstract:

There is significant debate on the evolution of retail marketing as an economy matures. In penetrating new markets, global brands are efficient in establishing a presence and replacing less effective competitors by engaging in superior advertising, pricing and sometimes quality. However, national brands adapt over time and may either partner with global brands in distribution and services or directly compete more efficiently in the new, open market. This explorative study investigates brand preferences in Saudi Arabia. As a conservative society, which is nevertheless highly commercialised, Saudi Arabia markets could be fragmenting with consumer preferences and rejections based on country of origin, globalisation, or perhaps regionalisation. To investigate this, an online survey was distributed to Saudis in Jeddah to gather data on their preferences for travel, technology, clothes and accessories, eating out, vehicles, and influential brands. The results from 710 valid responses were that there are distinct regional and national brand preferences among the young Saudi men who contributed to the survey. Apart from a preference for Saudi food providers, airline preferences were the United Emirates, holiday preferences were Europe, study and work preferences were the United States, hotel preferences were United States-based, car preferences were Japanese, and clothing preferences were United States-based. The results were broadly in line with international research findings; however, the study participants varied from Arab research findings by describing themselves as innovative in their purchase selections, rarely loyal (exception of Apple products) and continually seeking new brand experiences. This survey contributes to an understanding of evolving Saudi consumer preferences.

Keywords: Saudi marketing, globalisation, country of origin, brand preferences

Procedia PDF Downloads 240