Search results for: orthogonal design method

Authors: Opeyemi Atiba-Oyewo, Taile Y. Leswfi, Maurice S. Onyango, Christian Wolkersdorfer

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This paper describes the preparation of surface modified montmorillonite using hexadecyltrimethylammonium bromide (HDTMA-Br) for the removal of vanadium from mine water. The adsorbent before and after adsorption was characterised by Fourier transform infra-red (FT-IR), X-ray diffraction (XRD) and scanning electron microscopy (SEM), while the amount of vanadium adsorbed was determined by ICP-OES. The batch adsorption method was employed using vanadium concentrations in solution ranging from 50 to 320 mg/L and vanadium tailings seepage water from a South African mine. Also, solution pH, temperature and sorbent mass were varied. Results show that the adsorption capacity was affected by solution pH, temperature, sorbent mass and the initial concentration. Electrical conductivity of the mine water before and after adsorption was measured to estimate the total dissolved solids in the mine water. Equilibrium isotherm results revealed that vanadium sorption follows the Freundlich isotherm, indicating that the surface of the sorbent was heterogeneous. The pseudo-second order kinetic model gave the best fit to the kinetic experimental data compared to the first order and Elovich models. The results of this study may be used to predict the uptake efficiency of South Africa montmorillonite in view of its application for the removal of vanadium from mine water. However, the choice of this adsorbent for the uptake of vanadium or other contaminants will depend on the composition of the effluent to be treated.

Keywords: adsorption, vanadium, modified montmorillonite, equilibrium, kinetics, mine water

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Authors: Aïssa Rezzoug

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This paper is aimed to bring new elements that demonstrate the tide caused the groundwater to rise in the shoreline band, on which the urban areas occurs, especially in the western coastal cities of the Kingdom of Saudi Arabia like Jeddah. The reason for the last events of Jeddah inundation was the groundwater rise in the city coupled at the same time to a strong precipitation event. This paper will illustrate the tide participation in increasing the groundwater level significantly. It shows that the reason for internal groundwater recharge within the urban area is not only the excess of the water supply coming from surrounding areas, due to the human activity, with lack of sufficient and efficient sewage system, but also due to tide effect. The research study follows a quantitative method to assess groundwater level rise risks through many in-situ measurements and mathematical modelling. The proposed approach highlights groundwater level, in the urban areas of the city on the shoreline band, reaching the high tide level without considering any input from precipitation. Despite the small tide in the Red Sea compared to other oceanic coasts, the groundwater level is considerably enhanced by the tide from the seaside and by the freshwater table from the landside of the city. In these conditions, the groundwater level becomes high in the city and prevents the soil to evacuate quickly enough the surface flow caused by the storm event, as it was observed in the last historical flood catastrophe of Jeddah in 2009.

Keywords: flood, groundwater rise, Jeddah, tide

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Authors: Nagaletchumi Balasubramaniam, A. Mohd Isa

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Engineers have a leading role in planning, designing, building and ensuring a sustainable future. Universiti Tenaga Nasional (UNITEN) acknowledges this role by assigning sustainable development as one of the expected traits that a UNITEN student should have upon graduation, formalized as the Programme Outcomes 7 (PO7): Students graduating from the Bachelor of Electrical and Electronics (BEEE) program will have the ability to demonstrate knowledge of the impact of professional engineering solutions in environmental contexts and the need for sustainable development. This paper explores how PO7 is integrated within the BEEE (Hons) program in UNITEN under the framework of Outcome Base Education (OBE). Five technical core courses were specifically assigned by UNITEN to reflect attainment of PO7. Under UNITEN’s definition, the attainment criterion of a PO is set as 70/40. This means that 70% of the students taking the course achieve at least 40% of the full marks. The paper first gives an overview of the overall OBE system as applied in UNITEN, particularly describing the key and supporting courses approach adopted for each PO. Then, the paper reviews the mechanism in which PO7 is taught and assessed in the five assigned courses. Data on PO7 attainment from four of the five courses are collected and analyzed for two student cohorts to investigate the interrelationship between the courses assigned to PO7. It was found that the five courses have different mechanisms for assessing PO7, and that generally PO7 is attained for the assigned courses. This reflects positively on the UNITEN method for integrating sustainable development within the engineering undergraduate programme.

Keywords: direct assessment, engineering education, outcome base education, programme outcome, sustainable development

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Authors: Osayomwanbor E. Oghama, John O. Olomukoro

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The school environment, apart from home, is probably the most important indoor environment for children. Children spend as much as 80-90% of their indoor time either at school or at home; an average of 35 - 40 hours per week in schools, hence are at the risk of indoor air pollutants such as volatile organic compounds (VOCs). Concentrations of VOCs vary widely but are generally higher indoors than outdoors. This research was, therefore, carried out to evaluate the levels of VOCs in secondary school classrooms in Benin City, Edo State. Samples were obtained from a total of 18 classrooms in 6 secondary schools. Samples were collected 3 times from each school and from 3 different classrooms in each school using Draeger ORSA 5 tubes. Samplers were left to stay for a school-week (5 days). The VOCs detected and analyzed were benzene, ethlybenzene, isopropylbenzene, naphthalene, n-butylbenzene, n-propylbenzene, toluene, m-xylene, p-xylene, o-xylene, styrene, chlorobenzene, chloroform, 1,2-dichloropropane, 2,2-dichloropropane, tetrachloroethane, tetrahydrofuran, isopropyl acetate, α-pinene, and camphene. The results showed that chloroform, o-xylene, and styrene were the most abundant while α-pinene and camphene were the least abundant. The health risk assessment was done in terms of carcinogenic (CRI) and non-carcinogenic risks (THR). The CRI values of the schools ranged from 1.03 × 10-5 to 1.36 × 10-5 μg/m³ (a mean of 1.16 × 10-5 μg/m³) with School 6 and School 3 having the highest and lowest values respectively. The THR values of the study schools ranged from 0.071-0.086 μg/m³ (a mean of 0.078 μg/m³) with School 3 and School 2 having the highest and lowest values respectively. The results show that all the schools pose a potential carcinogenic risks having CRI values greater than the recommended limit of 1 × 10-6 µg/m³ and no non-carcinogenic risk having THR values less than the USEPA hazard quotient of 1 µg/m³. It is recommended that school authorities should ensure adequate ventilation in their schools, supplementing natural ventilation with mechanical sources, where necessary. In addition, indoor air quality should be taken into consideration in the design and construction of classrooms.

Keywords: carcinogenic risk indicator, health risk, indoor air, non-carcinogenic risk indicator, secondary schools, volatile organic compounds

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Authors: Gabor Varga, Krisztina Karadi, Zoltan Konya, Akos Kukovecz, Pal Sipos, Istvan Palinko

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Nickel can efficiently replace palladium in the Heck, Suzuki and Negishi reactions. This study focuses on the synthesis and catalytic application of Ni(II)-containing layered double hydroxides (LDHs) and layered triple hydroxides (LTHs). Our goals were to incorporate Ni(II) ions among the layers of LDHs or LTHs, or binding it to their surface or building it into their layers in such a way that their catalytic activities are maintained or even increased. The LDHs and LTHs were prepared by the co-precipitation method using ethylene glycol as co-solvent. In several cases, post-synthetic modifications (e.g., thermal treatment) were performed. After optimizing the synthesis conditions, the composites displayed good crystallinity and were free of byproducts. The success of the syntheses and the post-synthetic modifications was confirmed by relevant characterization methods (XRD, SEM, SEM-EDX and combined IR techniques). Catalytic activities of the produced and well-characterized solids were investigated through the Heck reaction. The composites behaved as efficient, recyclable catalysts in the Heck reaction between 4-bromoanisole and styrene. Through varying the reaction parameters, we were able to obtain acceptable conversions under mild conditions. Our study highlights the possibility of the application of Ni(II)-containing composites as efficient catalysts in coupling reactions.

Keywords: layered double hydroxide, layered triple hydroxide, heterogeneous catalysis, heck reaction

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Authors: Seyed Mohammad Ali Zahedi

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This field experiment was conducted in Isfahan in 2011 in order to study the effect of plant density and planting pattern on growth, yield and quality of silage corn (SC 704) using a randomized complete block design with split plot layout and four replications. The main plot consisted of three planting patterns (60 and 75 cm single planting row and 75 cm double planting row referred to as 60S, 75S and 75T, respectively). The subplots consisted of four levels of plant densities (65000, 80000, 95000 and 110000 plants per hectare). Each subplot consisted of 7 rows, each with 10m length. Vegetative and reproductive characteristics of plants at silking and hard dough stages (when the plants were harvested for silage) were evaluated. Results of variance analysis showed that the effects of planting pattern and plant density were significant on leaf area per plant, leaf area index (at silking), plant height, stem diameter, dry weights of leaf, stem and ear in silking and harvest stages and on fresh and dry yield, dry matter percentage and crude protein percentage at harvest. There was no planting pattern × plant density interaction for these parameters. As row space increased from 60 cm with single planting to 75 cm with single planting, leaf area index and plant height increased, but leaf area per plant, stem diameter, dry weight of leaf, stem and ear, dry matter percentage, dry matter yield and crude protein percentage decreased. Dry matter yield reduced from 24.9 to 18.5 t/ha and crude protein percentage decreased from 6.11 to 5.60 percent. When the plant density increased from 65000 to 110000 plant per hectare, leaf area index, plant height, dry weight of leaf, stem and ear and dry matter yield increased from 19.2 to 23.3 t/ha, whereas leaf area per plant, stem diameter, dry matter percentage and crude protein percentage decreased from 6.30 to 5.25. The best results were obtained with 60 cm row distance with single planting and 110000 plants per hectare.

Keywords: silage corn, plant density, planting pattern, yield

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Authors: Francesca Nicolosi, Teresa Cosola

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Climate changes in Mediterranean areas, such as the increase of average seasonal temperatures, the urban heat island phenomenon, the intensification of solar radiation and the extreme weather threats, cause disruption events, so that climate adaptation has become a pressing issue. Due to the strategic role that the built heritage holds in terms of environmental impact and energy waste and its potentiality, it is necessary to assess the vulnerability and the adaptive capacity of the existing building to climate change, in order to define different mitigation scenarios. The aim of this research work is to define an optimized and integrated methodology for the assessment of resilience levels and adaptation scenarios for existing buildings in Mediterranean urban areas. Moreover, the study of resilience indicators allows us to define building environmental and energy performance in order to identify the design and technological solutions for the improvement of the building and its urban area potentialities. The methodology identifies step-by-step different phases, starting from the detailed study of characteristic elements of urban system: climatic, natural, human, typological and functional components are analyzed in their critical factors and their potential. Through the individuation of the main perturbing factors and the vulnerability degree of the system to the risks linked to climate change, it is possible to define mitigation and adaptation scenarios. They can be different, according to the typological, functional and constructive features of the analyzed system, divided into categories of intervention, and characterized by different analysis levels (from the single building to the urban area). The use of software simulations allows obtaining information on the overall behavior of the building and the urban system, to generate predictive models in the medium and long-term environmental and energy retrofit and to make a comparative study of the mitigation scenarios identified. The studied methodology is validated on a case study.

Keywords: climate impact mitigation, energy efficiency, existing building heritage, resilience

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Authors: Esra Zengin, Sinan Akkar

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Reliable and accurate prediction of nonlinear structural response requires specification of appropriate earthquake ground motions to be used in nonlinear time history analysis. The current research has mainly focused on selection and manipulation of real earthquake records that can be seen as the most critical step in the performance based seismic design and assessment of the structures. Utilizing amplitude scaled ground motions that matches with the target spectra is commonly used technique for the estimation of nonlinear structural response. Representative ground motion ensembles are selected to match target spectrum such as scenario-based spectrum derived from ground motion prediction equations, Uniform Hazard Spectrum (UHS), Conditional Mean Spectrum (CMS) or Conditional Spectrum (CS). Different sets of criteria exist among those developed methodologies to select and scale ground motions with the objective of obtaining robust estimation of the structural performance. This study presents ground motion selection and scaling procedure that considers the spectral variability at target demand with the level of ground motion dispersion. The proposed methodology provides a set of ground motions whose response spectra match target median and corresponding variance within a specified period interval. The efficient and simple algorithm is used to assemble the ground motion sets. The scaling stage is based on the minimization of the error between scaled median and the target spectra where the dispersion of the earthquake shaking is preserved along the period interval. The impact of the spectral variability on nonlinear response distribution is investigated at the level of inelastic single degree of freedom systems. In order to see the effect of different selection and scaling methodologies on fragility curve estimations, results are compared with those obtained by CMS-based scaling methodology. The variability in fragility curves due to the consideration of dispersion in ground motion selection process is also examined.

Keywords: ground motion selection, scaling, uncertainty, fragility curve

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Authors: Nabil Mezhoud

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The economic operation of electric energy generating systems is one of the predominant problems in energy systems. Due to the need for better reliability, high energy quality, lower losses, lower cost and a clean environment, the application of renewable and sustainable energy sources, such as wind energy, solar energy, etc., in recent years has become more widespread. In this work, one of a bio-inspired meta-heuristic algorithm inspired by the flashing behavior of fireflies at night called the Firefly Algorithm (FFA) is applied to solve the Optimal Energy Management (OEM) and the environmental index (EI) problems of a micro-grid (MG) operating by Renewable and Sustainable Generation Systems (RSGS). Our main goal is to minimize the nonlinear objective function of an electrical microgrid, taking into account equality and inequality constraints. The FFA approach was examined and tested on a standard MG system composed of different types of RSGS, such as wind turbines (WT), photovoltaic systems (PV), and non-renewable energy, such as fuel cells (FC), micro turbine (MT), diesel generator (DEG) and loads with energy storage systems (ESS). The results are promising and show the effectiveness and robustness of the proposed approach to solve the OEM and the EI problems. The results of the proposed method have been compared and validated with those known references published recently.

Keywords: renewable energy sources, energy management, distributed generator, micro-grids, firefly algorithm

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Authors: Juhanita Jiman

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Malaysia is a unique country with multifaceted society; rich with its beautiful cultural values. It has been a long assimilation process for Malaysia to emerge its national identity. Malaysian government has been working hard for centuries to keep its people together in harmony. Cultural identity is identified to be ‘container’ that brings Malaysians together. The uniqueness of Malaysian cultures can actually be exploited for the benefit of the nation. However, this unique culture is somehow being threatened by those imported foreign values. If not closely monitored, these foreign influences can bring more damages than good. This paper aims to study elements in Upin and Ipin animation series and investigate how this series could help to educate local children with good moral and behaviour without being too serious and sententious. Upin and Ipin is chosen as a study to investigate the effectiveness of animation as a media of communication to promote positive values amongst pre-school children. Purposive sampling method was employed to determine the sample of studies hence pre-school children from Putrajaya Presint 9(2) school were chosen to take part in this study. The findings of this study demonstrate positive suggestions on how animation programmes being shown on TV can play significant roles in children social development and inculcate good moral behaviour as well as social skills among children and people around them.

Keywords: animation characters, children informal education, foreign influences, moral values

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Authors: Jiajia Peng, Yijun Dong, Jianjun Ren, Yu Zhao

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Objectives: Understanding the association between sleep traits and tinnitus could help prevent and provide appropriate interventions against tinnitus. Therefore, this study aimed to assess the relationship between different sleep patterns and tinnitus. Design: A cross-sectional analysis using baseline data (2006–2010, n=168,064) by logistic regressions was conducted to evaluate the association between sleep traits (including the overall health sleep score and five sleep behaviors), and the occurrence (yes/no), frequency (constant/transient), and severity (upsetting/not upsetting) of tinnitus. Further, a prospective analysis of participants without tinnitus at baseline (n=9,581) was performed, who had been followed up for seven years (2012–2019) to assess the association between new-onset tinnitus and sleep characteristics. Moreover, a subgroup analysis was also carried out to estimate the differences in sex by dividing the participants into male and female groups. A sensitivity analysis was also conducted by excluding ear-related diseases to avoid their confounding effects on tinnitus (n=102,159). Results: In the cross-sectional analysis, participants with “current tinnitus” (OR: 1.13, 95% CI: 1.04–1.22, p=0.004) had a higher risk of having a poor overall healthy sleep score and unhealthy sleep behaviors such as short sleep durations (OR: 1.09, 95% CI: 1.04–1.14, p<0.001), late chronotypes (OR: 1.09, 95% CI: 1.05–1.13, p<0.001), and sleeplessness (OR: 1.16, 95% CI: 1.11–1.22, p<0.001) than those participants who “did not have current tinnitus.” However, this trend was not obvious between “constant tinnitus” and “transient tinnitus.” When considering the severity of tinnitus, the risk of “upsetting tinnitus” was obviously higher if participants had lower overall healthy sleep scores (OR: 1.31, 95% CI: 1.13–1.53, p<0.001). Additionally, short sleep duration (OR: 1.22, 95% CI: 1.12–1.33, p<0.001), late chronotypes (OR: 1.13, 95% CI: 1.04–1.22, p=0.003), and sleeplessness (OR: 1.43, 95% CI: 1.29–1.59, p<0.001) showed positive correlations with “upsetting tinnitus.” In the prospective analysis, sleeplessness presented a consistently significant association with “upsetting tinnitus” (RR: 2.28, P=0.001). Consistent results were observed in the sex subgroup analysis, where a much more pronounced trend was identified in females compared with males. The results of the sensitivity analysis were consistent with those of the cross-sectional and prospective analyses. Conclusions: Different types of sleep disturbance may be associated with the occurrence and severity of tinnitus; therefore, precise interventions for different types of sleep disturbance, particularly sleeplessness, may help in the prevention and treatment of tinnitus.

Keywords: tinnitus, sleep, sleep behaviors, sleep disturbance

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Authors: Getachew Kuma Watiro

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The need for solar energy is constantly increasing and it is widely available on the earth’s surface. Photovoltaic technology is one of the most capable of all viable energy technology and is seen as a promising approach to the control era as it is readily available and has zero carbon emissions. Inexpensive and versatile solar cells have achieved the conversion efficiency and long life of dye-sensitized solar cells, improving the conversion efficiency from the sun to electricity. DSSCs have received a lot of attention for Various potential commercial uses, such as mobile devices and portable electronic devices, as well as integrated solar cell modules. The systematic reviews were used to show the critical impact of additive C-dots in the Dye-Sensitized solar cell for energy application technology. This research focuses on the following methods to synthesize nanoparticles such as facile, polyol, calcination, and hydrothermal technique. In addition to these, there are additives C-dots by the Hydrothermal method. This study deals with the progressive development of DSSC in photovoltaic technology. The applications of single and heterojunction structure technology devices were used (ZnO, NiO, SnO2, and NiO/ZnO/N719) and applied some additives C-dots (ZnO/C-dots /N719, NiO/C-dots /N719, SnO2 /C-dots /N719 and NiO/ZnO/C-dots/N719) and the effects of C-dots were reviewed. More than all, the technology of DSSC with C-dots enhances efficiency. Finally, recommendations have been made for future research on the application of DSSC with the use of these additives.

Keywords: dye-sensitized solar cells, heterojunction’s structure, carbon dot, conversion efficiency

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Authors: Joseph Amponsah

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This research proposes an equation to predict and determine the momentum source equation term after factoring in the radial friction between the fluid and the blades and the impeller's propulsive power. This research aims to look at how CFD software can be used to predict the effect of flows in nuclear reactor stirred tanks through a momentum source equation and the concentration distribution of tracers that have been introduced in reactor tanks. The estimated findings, including the dimensionless concentration curves, power, and pumping numbers, dimensionless velocity profiles, and mixing times 4, were contrasted with results from tests in stirred containers. The investigation was carried out in Part I for vessels that were agitated by one impeller on a central shaft. The two types of impellers employed were an ordinary Rushton turbine and a 6-bladed 45° pitched blade turbine. The simulations made use of numerous reference frame techniques and the common k-e turbulence model. The impact of the grid type was also examined; unstructured, structured, and unique user-defined grids were looked at. The CFD model was used to simulate the flow field within the Rushton turbine nuclear reactor stirred tank. This method was validated using experimental data that were available close to the impeller tip and in the bulk area. Additionally, analyses of the computational efficiency and time using MRF and SM were done.

Keywords: Ansys fluent, momentum equation, CFD, prediction

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Authors: Nuraddeen Usman, Khiruddin Abdullah, Mohd Nawawi, Amin Khalil Ismail

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A magnetic survey is carried out in order to locate the remains of construction items, specifically concrete pillars. The conventional Euler deconvolution technique can perform the task but it requires the use of fixed structural index (SI) and the construction items are made of materials with different shapes which require different SI (unknown). A Euler deconvolution technique that estimate background, horizontal coordinate (xo and yo), depth and structural index (SI) simultaneously is prepared and used for this task. The synthetic model study carried indicated the new methodology can give a good estimate of location and does not depend on magnetic latitude. For field data, both the total magnetic field and gradiometer reading had been collected simultaneously. The computed vertical derivatives and gradiometer readings are compared and they have shown good correlation signifying the effectiveness of the method. The filtering is carried out using automated procedure, analytic signal and other traditional techniques. The clustered depth solutions coincided with the high amplitude/values of analytic signal and these are the possible target positions of the concrete pillars being sought. The targets under investigation are interpreted to be located at the depth between 2.8 to 9.4 meters. More follow up survey is recommended as this mark the preliminary stage of the work.

Keywords: concrete pillar, magnetic survey, geotechnical investigation, Euler Deconvolution

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Authors: Yu Sin Syu

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Objective: The study aimed to improve the patient guidance satisfaction of patients hospitalized in iodine-131 isolation rooms, as well as the patient guidance completion rate for such patients. Method: A patient care guidance checklist and patient care guidance satisfaction questionnaire were administered to 29 patients who had previously been hospitalized in iodine-131 isolation rooms. The evaluation was conducted on a one-on-one basis, and its results showed that the patients’ satisfaction with patient guidance was only 3.7 points and that the completion rate for the patient guidance performed by nurses was only 67%. Therefore, various solutions were implemented to create a more complete patient guidance framework for nurses, including the incorporation of regular care-related training in in-service education courses; the establishment of patient care guidance standards for patients in iodine-131 isolation rooms; the establishment of inpatient care standards and auditing processes for iodine-131 isolation rooms; the creation of an introductory handbook on ward environment; Invite other the care team the revision of iodine-131 health education brochures; the creation of visual cards and videos covering equipment operation procedures; and introduction of QR codes. Results: Following the implementation of the above measures, the overall satisfaction of patients hospitalized in iodine-131 isolation rooms increased from 3.7 points to 4.6 points, and the completion rate for patient guidance rose from 67% to 100%. Conclusion: Given the excellent results achieved in this study, it is hoped that this nursing project can serve as a benchmark for other relevant departments.

Keywords: admission care guidance, guidance satisfaction, integrity, Iodine131 isolation

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Authors: N. J. Nawarathna, N. R. Kmarasinghe, D. Chandrasekara, B. M. R. S. Balasooriya, R. A. A. Shaminda, R. J. K. Senevirathne

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Introduction: Thyroid malignancy associated with hyperthyroidism is considered rare. Retrospective studies have shown the incidence of thyroid malignancy in hyperthyroid patients to be low (0.7-8.5%). To assess the clinical relevance of this association, thyroid status in a cohort of patients with thyroid malignancy were analyzed. Method: Thyroid malignancies diagnosed histologically in 56 patients, over a 18 month period beginning from April 2013, in a single surgical unit at Teaching Hospital Kandy were included. Preoperative patient details and progression of thyroid status were asessed with Thyroid Stimulating Hormone, free Thyroxin and free Triiodothyronine levels. Results: Amongst 56 patients Papillary carcinoma was diagnosed in 44(78.6%), follicular carcinomas in 7(12.5%) and 5(8.9%) with medullary and anaplastic carcinomas. 12(21.4%) were males and 44(78.6%) were females. 20(35.7%) were less than 40years, 29(51.8%) were between 40 to 59years and 7(12.5%) were above 59years. Cross tabulation of Type of carcinoma with Gender revealed likelihood ratio of 6.908, Significance p = 0.032. Biochemically 12(21.4%) were hyperthyroid. Out of them 5(41.7%) had primary hyperthyroidism and 7(58.3%) had secondary hyperthyroidism. Mean age of euthyroid patients was 43.77years (SD 10.574) and hyperthyroid patients was 53.25years(SD 16.057). Independent Samples Test t is -2.446, two tailed significance p =0.018. When cross tabulate thyroid status with Age group Likelihood Ratio was 9.640, Significance p = 0.008. Conclusion: Papillary carcinoma is seen more among females. Among the patients with thyroid carcinomas, those with biochemically proven hyperthyroidism were more among the older age group than those who were euthyroid. Hence careful evaluation of elderly hyperthyroid patients to select the most suitable therapeutic approach is justified.

Keywords: age, hyperthyroidism, thyroid malignancy, thyroid status

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Authors: Narendra Nath Patra

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Several recent studies reinforce the existence of a thick molecular disc in galaxies along with the dynamically cold thin disc. Assuming a two-component molecular disc, we model the disc of NGC 6946 as a four-component system consists of stars, HI, thin disc molecular gas, and thick disc molecular gas in vertical hydrostatic equilibrium. Following, we set up the joint Poisson-Boltzmann equation of hydrostatic equilibrium and solve it numerically to obtain a three-dimensional density distribution of different baryonic components. Using the density solutions and the observed rotation curve, we further build a three-dimensional dynamical model of the molecular disc and consecutively produce simulated CO spectral cube and spectral width profile. We find that the simulated spectral width profiles distinguishably differs for different assumed thick disc molecular gas fraction. Several CO spectral width profiles are then produced for different assumed thick disc molecular gas fractions and compared with the observed one to obtain the best fit thick disc molecular gas fraction profile. We find that the thick disc molecular gas fraction in NGC 6946 largely remains constant across its molecular disc with a mean value of 0.70 +/- 0.09. We also estimate the amount of extra-planar molecular gas in NGC 6946. We find 60% of the total molecular gas is extra-planar at the central region, whereas this fraction reduces to ~ 35% at the edge of the molecular disc. With our method, for the first time, we estimate the thick disc molecular gas fraction as a function of radius in an external galaxy with sub-kpc resolution.

Keywords: galaxies: kinematics and dynamic, galaxies: spiral, galaxies: structure , ISM: molecules, molecular data

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Authors: Bi-Huei Tsai

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

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

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Authors: Vivek Thorat, Suhasini Desai

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The hybrid electric vehicle is widely accepted as a promising short to mid-term technical solution due to noticeably improved efficiency and low emissions at competitive costs. Retro fitment of hybrid components into a conventional vehicle for achieving better performance is the best solution so far. But retro fitment includes major modifications into a conventional vehicle with a high cost. This paper focuses on the development of a P3x hybrid prototype with rear wheel drive parallel hybrid electric Light Commercial Vehicle (LCV) with minimum and low-cost modifications. This diesel Hybrid LCV is different from another hybrid with regard to the powertrain. The additional powertrain consists of continuous contact helical gear pair followed by chain and sprocket as a coupler for traction motor. Vehicle powertrain which is designed for the intended high-speed application. This work focuses on targeting of design, development, and packaging of this unique parallel diesel-electric vehicle which is based on multimode hybrid advantages. To demonstrate the practical applicability of this transmission with P3x hybrid configuration, one concept prototype vehicle has been build integrating the transmission. The hybrid system makes it easy to retrofit existing vehicle because the changes required into the vehicle chassis are a minimum. The additional system is designed for mainly five modes of operations which are engine only mode, electric-only mode, hybrid power mode, engine charging battery mode and regenerative braking mode. Its driving performance, fuel economy and emissions are measured and results are analyzed over a given drive cycle. Finally, the output results which are achieved by the first vehicle prototype during experimental testing is carried out on a chassis dynamometer using MIDC driving cycle. The results showed that the prototype hybrid vehicle is about 27% faster than the equivalent conventional vehicle. The fuel economy is increased by 20-25% approximately compared to the conventional powertrain.

Keywords: P3x configuration, LCV, hybrid electric vehicle, ROMAX, transmission

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Authors: Marcela de Oliveira, Guilherme Giacomini, Allan Felipe Fattori Alves, Ana Luiza Menegatti Pavan, Maria Eugenia Dela Rosa, Fernando Antonio Bacchim Neto, Diana Rodrigues de Pina

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It is estimated that each year one death every 10 seconds (about 2 million deaths) in the world is attributed to tuberculosis (TB). Even after effective treatment, TB leaves sequelae such as, for example, pulmonary fibrosis, compromising the quality of life of patients. Evaluations of the aforementioned sequel are usually performed subjectively by radiology specialists. Subjective evaluation may indicate variations inter and intra observers. The examination of x-rays is the diagnostic imaging method most accomplished in the monitoring of patients diagnosed with TB and of least cost to the institution. The application of computational algorithms is of utmost importance to make a more objective quantification of pulmonary impairment in individuals with tuberculosis. The purpose of this research is the use of computer algorithms to quantify the pulmonary impairment pre and post-treatment of patients with pulmonary TB. The x-ray images of 10 patients with TB diagnosis confirmed by examination of sputum smears were studied. Initially the segmentation of the total lung area was performed (posteroanterior and lateral views) then targeted to the compromised region by pulmonary sequel. Through morphological operators and the application of signal noise tool, it was possible to determine the compromised lung volume. The largest difference found pre- and post-treatment was 85.85% and the smallest was 54.08%.

Keywords: algorithm, radiology, tuberculosis, x-rays exam

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Authors: Zhao Bo

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The TiO2-Na2SO3 and SiO2-Na2SO3 nano-fluids were prepared using ultrasonic dispertion method without any surfactant addition to study the influence of nano-fluids on the mass transfer during forced sulfite oxidation in a thermostatic stirred tank, and the kinetic viscosity of nano-fluids was measured. The influence of temperature (30 ℃ ~ 50 ℃), solid loading of fine particle (0 Kg/m³~1.0 Kg/m³), stirring speed (50 r/min ~ 400 r/min), and particle size (10 nm~100 nm) on the average oxygen absorption rate were investigated in detail. Both TiO2 nano-particles and SiO2 nano-particles could remarkably improve the gas-liquid mass transfer. Oxygen absorption enhancement factor increases with the increase of solid loading of nano-particles to a critical value and then decreases with further increase of solid loading under 30℃. Oxygen absorption rate together with absorption enhancement factor increases with stirring speed. However, oxygen absorption enhancement factor decreases with the increase of temperature due to aggregation of nano-particles. Further inherent relationship between particle size, loading, surface area, viscosity, stirring speed, temperature, adsorption, desorption, and mass transfer was discussed in depth by analyzing the interaction mechanism.

Keywords: fine particles, nano-fluid, mass transfer enhancement, solid loading

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Authors: Gabriela V. Angeles Perez, Jose Castillejos Lopez, Araceli L. Reyes Cabello, Emilio Bravo Grajales, Adriana Perez Espinosa, Jose L. Quiroz Fabian

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Road traffic accidents are among the principal causes of traffic congestion, causing human losses, damages to health and the environment, economic losses and material damages. Studies about traditional road traffic accidents in urban zones represents very high inversion of time and money, additionally, the result are not current. However, nowadays in many countries, the crowdsourced GPS based traffic and navigation apps have emerged as an important source of information to low cost to studies of road traffic accidents and urban congestion caused by them. In this article we identified the zones, roads and specific time in the CDMX in which the largest number of road traffic accidents are concentrated during 2016. We built a database compiling information obtained from the social network known as Waze. The methodology employed was Discovery of knowledge in the database (KDD) for the discovery of patterns in the accidents reports. Furthermore, using data mining techniques with the help of Weka. The selected algorithms was the Maximization of Expectations (EM) to obtain the number ideal of clusters for the data and k-means as a grouping method. Finally, the results were visualized with the Geographic Information System QGIS.

Keywords: data mining, k-means, road traffic accidents, Waze, Weka

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Authors: Rouhallah Bagheri, Morteza Mahmoudi, Hadi Moheb-Alizadeh

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This paper aims at developing a multi-objective model for supplier selection and order allocation problem in stochastic environment, where purchasing cost, percentage of delivered items with delay and percentage of rejected items provided by each supplier are supposed to be stochastic parameters following any arbitrary probability distribution. In this regard, dependent chance programming is used which maximizes probability of the event that total purchasing cost, total delivered items with delay and total rejected items are less than or equal to pre-determined values given by decision maker. The abovementioned stochastic multi-objective programming problem is then transformed into a stochastic single objective programming problem using minimum deviation method. In the next step, the further problem is solved applying a genetic algorithm, which performs a simulation process in order to calculate the stochastic objective function as its fitness function. Finally, the impact of stochastic parameters on the given solution is examined via a sensitivity analysis exploiting coefficient of variation. The results show that whatever stochastic parameters have greater coefficients of variation, the value of the objective function in the stochastic single objective programming problem is deteriorated.

Keywords: supplier selection, order allocation, dependent chance programming, genetic algorithm

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Authors: Shrawan Baghel, Helen Cathcart, Biall J. O'Reilly

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Amorphous drug formulations have great potential to enhance solubility and thus bioavailability of BCS class II drugs. However, the higher free energy and molecular mobility of the amorphous form lowers the activation energy barrier for crystallization and thermodynamically drives it towards the crystalline state which makes them unstable. Accurate determination of the crystallization tendency/kinetics is the key to the successful design and development of such systems. In this study, dipyridamole (DPM) and cinnarizine (CNZ) has been selected as model compounds. Thermodynamic fragility (m_T) is measured from the heat capacity change at the glass transition temperature (Tg) whereas dynamic fragility (m_D) is evaluated using methods based on extrapolation of configurational entropy to zero 〖(m〗_(D_CE )), and heating rate dependence of Tg 〖(m〗_(D_Tg)). The mean relaxation time of amorphous drugs was calculated from Vogel-Tammann-Fulcher (VTF) equation. Furthermore, the correlation between fragility and glass forming ability (GFA) of model drugs has been established and the relevance of these parameters to crystallization of amorphous drugs is also assessed. Moreover, the crystallization kinetics of model drugs under isothermal conditions has been studied using Johnson-Mehl-Avrami (JMA) approach to determine the Avrami constant ‘n’ which provides an insight into the mechanism of crystallization. To further probe into the crystallization mechanism, the non-isothermal crystallization kinetics of model systems was also analysed by statistically fitting the crystallization data to 15 different kinetic models and the relevance of model-free kinetic approach has been established. In addition, the crystallization mechanism for DPM and CNZ at each extent of transformation has been predicted. The calculated fragility, glass forming ability (GFA) and crystallization kinetics is found to be in good correlation with the stability prediction of amorphous solid dispersions. Thus, this research work involves a multidisciplinary approach to establish fragility, GFA and crystallization kinetics as stability predictors for amorphous drug formulations.

Keywords: amorphous, fragility, glass forming ability, molecular mobility, mean relaxation time, crystallization kinetics, stability

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Authors: Dimitra C. Banti, Gesthimani Liona, Petros Samaras, Manasis Mitrakas

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Municipal and industrial wastewaters are often treated biologically, by the activated sludge process (ASP). The ASP not only requires large aeration and sedimentation tanks, but also generates large quantities of excess sludge. An alternative technology is the membrane bioreactor (MBR), which replaces two stages of the conventional ASP—clarification and settlement—with a single, integrated biotreatment and clarification step. The advantages offered by the MBR over conventional treatment include reduced footprint and sludge production through maintaining a high biomass concentration in the bioreactor. Notwithstanding these advantages, the widespread application of the MBR process is constrained by membrane fouling. Fouling leads to permeate flux decline, making more frequent membrane cleaning and replacement necessary and resulting to increased operating costs. In general, membrane fouling results from the interaction between the membrane material and the components in the activated sludge liquor. The latter includes substrate components, cells, cell debris and microbial metabolites, such as Extracellular Polymeric Substances (EPS) and Sludge Microbial Products (SMPs). The challenge for effective MBR operation is to minimize the rate of Transmembrane Pressure (TMP) increase. This can be achieved by several ways, one of which is the addition of specific additives, that enhance the coagulation and flocculation of compounds, which are responsible for fouling, hence reducing biofilm formation on the membrane surface and limiting the fouling rate. In this project the effectiveness of a non-commercial composite coagulant was studied as an agent for fouling control in a lab scale MBR system consisting in two aerated tanks. A flat sheet membrane module with 0.40 um pore size was submerged into the second tank. The system was fed by50 L/d of municipal wastewater collected from the effluent of the primary sedimentation basin. The TMP increase rate, which is directly related to fouling growth, was monitored by a PLC system. EPS, MLSS and MLVSS measurements were performed in samples of mixed liquor; in addition, influent and effluent samples were collected for the determination of physicochemical characteristics (COD, BOD5, NO3-N, NH4-N, Total N and PO4-P). The coagulant was added in concentrations 2, 5 and 10mg/L during a period of 2 weeks and the results were compared with the control system (without coagulant addition). EPS fractions were extracted by a three stages physical-thermal treatment allowing the identification of Soluble EPS (SEPS) or SMP, Loosely Bound EPS (LBEPS) and Tightly Bound EPS (TBEPS). Proteins and carbohydrates concentrations were measured in EPS fractions by the modified Lowry method and Dubois method, respectively. Addition of 2 mg/L coagulant concentration did not affect SEPS proteins in comparison with control process and their values varied between 32 to 38mg/g VSS. However a coagulant dosage of 5mg/L resulted in a slight increase of SEPS proteins at 35-40 mg/g VSS while 10mg/L coagulant further increased SEPS to 44-48mg/g VSS. Similar results were obtained for SEPS carbohydrates. Carbohydrates values without coagulant addition were similar to the corresponding values measured for 2mg/L coagulant; the addition of mg/L coagulant resulted to a slight increase of carbohydrates SEPS to 6-7mg/g VSS while a dose of 10 mg/L further increased carbohydrates content to 9-10mg/g VSS. Total LBEPS and TBEPS, consisted of proteins and carbohydrates of LBEPS and TBEPS respectively, presented similar variations by the addition of the coagulant. Total LBEPS at 2mg/L dose were almost equal to 17mg/g VSS, and their values increased to 22 and 29 mg/g VSS during the addition of 5 mg/L and 10 mg/L of coagulant respectively. Total TBEPS were almost 37 mg/g VSS at a coagulant dose of 2 mg/L and increased to 42 and 51 mg/g VSS at 5 mg/L and 10 mg/L doses, respectively. Therefore, it can be concluded that coagulant addition could potentially affect microorganisms activities, excreting EPS in greater amounts. Nevertheless, EPS increase, mainly SEPS increase, resulted to a higher membrane fouling rate, as justified by the corresponding TMP increase rate. However, the addition of the coagulant, although affected the EPS content in the reactor mixed liquor, did not change the filtration process: an effluent of high quality was produced, with COD values as low as 20-30 mg/L.

Keywords: extracellular polymeric substances, MBR, membrane fouling, EPS

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Authors: Bahar Basturk, Secil Celik Erbas, Sevket Can Sarikaya

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Composites combining the particulates and polymer components have attracted great interest in various application areas such as packaging, furniture, electronics and automotive industries. For strengthening the plastic matrices, the utilization of natural fillers instead of traditional reinforcement materials has received increased attention. The properties of natural filler based polymer composites (NFPC) may be improved by applying proper surface modification techniques to the powder phase of the structures. In this study, acorn powder-epoxy and pine corn powder-epoxy composites containing up to 45% weight percent particulates were prepared by casting method. Alkali treatment and acetylation techniques were carried out to the natural particulates for investigating their influences under mechanical forces. The effects of filler type and content on the tensile properties of the composites were compared with neat epoxy. According to the quasi-static tensile tests, the pine cone based composites showed slightly higher rigidity and strength properties compared to the acorn reinforced samples. Furthermore, the structures independent of powder type and surface modification technique, showed higher tensile properties with increasing the particle content.

Keywords: natural fillers, polymer composites, surface modifications, tensile properties

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Authors: Majid Alizadeh, Sina Nematizadeh, Hassan Esmailpour

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The mutual effects of hospitality and the environment are undeniable, so that the tourism industry has major harmful effects on the environment. Hotels, as one of the most important pillars of the hospitality industry, have significant effects on the environment. Green marketing is a promising strategy in response to the growing concerns about the environment. A green hotel marketing model was proposed using a grounded theory approach in the hotel industry. The study was carried out as a mixed method study. Data gathering in the qualitative phase was done through literature review and In-depth, semi-structured interviews with 10 experts in green marketing using snowball technique. Following primary analysis, open, axial, and selective coding was done on the data, which yielded 69 concepts, 18 categories and six dimensions. Green hotel (green product) was adopted as the core phenomenon. In the quantitative phase, data were gleaned using 384 questionnaires filled-out by hotel guests and descriptive statistics and Structural equation modeling (SEM) were used for data analysis. The results indicated that the mediating role of behavioral response between the ecological literacy, trust, marketing mix and performance was significant. The green marketing mix, as a strategy, had a significant and positive effect on guests’ behavioral response, corporate green image, and financial and environmental performance of hotels.

Keywords: green marketing, sustainable development, hospitality, grounded theory, structural equations model

Procedia PDF Downloads 58

Authors: Alireza Mirzaee, Soosan Abdollahi, Mohammad Abdollahi

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Unreinforced Masonry (URM) wall is vulnerable in resisting horizontal load such as wind and seismic loading. It is due to the low tensile strength of masonry, the mortar connection between the brick units. URM structures are still widely used in the world as an infill wall and commonly constructed with door and window openings. This research aimed to investigate the behavior of URM wall with openings when horizontal load acting on it and developed load-drift relationship of the wall. The finite element (FE) method was chosen to numerically simulate the behavior of URM with openings. In this research, ABAQUS, commercially available FE software with explicit solver was employed. In order to ensure the numerical model can accurately represent the behavior of an URM wall, the model was validated for URM wall without openings using available experimental results. Load-displacement relationship of numerical model is well agreed with experimental results. Evidence shows the same load displacement curve shape obtained from the FE model. After validating the model, parametric study conducted on URM wall with openings to investigate the influence of area of openings and pre-compressive load on the horizontal load capacity of the wall. The result showed that the increasing of area of openings decreases the capacity of the wall in resisting horizontal loading. It is also well observed from the result that capacity of the wall increased with the increasing of pre-compressive load applied on the top of the walls.

Keywords: masonry constructions, performance at earthquake, MSJC-08 (ASD), bearing wall, tie-column

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Authors: Mirjana Dragas, Marli Gonan Bozac, Morena Paulisic

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Corporate social responsibility (CSR) is a balance between strategic and financial goals of companies, as well as social needs. The integration of competitive strategy and CSR in food and beverage industry has allowed companies to find new sources of competitive advantage. The paper discusses the fact that socially responsible companies encourage co-operation with socially responsible suppliers in order to strengthen market competitiveness. In addition to the descriptive interpretation of the results obtained by a questionnaire, factor analysis was used, while principal components analysis was applied as a factor extraction method. The research results based on two multiple regression analyses show that: (1) selecting the CSR supplier explains a statistically significant part of the variance of the results on the scale of financial aspects of competitiveness (as much as 44.7% of the explained variance); and (2) selecting the CSR supplier is a significant predictor of non-financial aspects of competitiveness (explains 43.9% of the variance of the results on the scale of non-financial aspects of competitiveness). A successful competitive strategy must ultimately support the growth strategy. This implies an analytical approach to finding factors that influence competitiveness through socially sustainable solutions and satisfactory top management decisions.

Keywords: competitiveness, corporate social responsibility, food and beverage industry, supply chain decision making

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Authors: Mohammed Al-Bloushi, Sanghyun Jeong, Torove Leiknes

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Biofouling in the open recirculating cooling water systems may cause biological corrosion, which can reduce the performance, increase the energy consummation and lower heat exchange efficiencies of the cooling tower. Seawater cooling towers are prone to biofouling due to the presences of organic and inorganic compounds in the seawater. The availability of organic and inorganic nutrients, along with sunlight and continuous aeration of the cooling tower contributes to an environment that is ideal for microbial growth. Various microorganisms (algae, fungi, and bacteria) can grow in a cooling tower system under certain environmental conditions. The most commonly being used method to control the biofouling in the cooling tower is the addition of biocides such as chlorination. In this study, algae containing diatom and green algae were added to the cooling tower basin, and its viability was monitored in the recirculating cooling seawater loop as well as in the cooling tower basin. Continuous addition of biocides was employed in pilot-scale seawater cooling towers, and it was operated continuously for 2 months. Three different types of oxidizing biocides, namely chlorine, chlorine dioxide and ozone, were tested. The results showed that all biocides were effective in keeping the biological growth to the minimum regardless of algal addition. Amongst the biocides, ozone could reduce 99% of total live cells of bacteria and algae, followed by chlorine dioxide at 97%, while the conventional chlorine showed only 89% reduction in the bioactivities.

Keywords: algae, biocide, biofouling, seawater cooling tower

Procedia PDF Downloads 223