Search results for: prior and posterior distribution

Authors: Hemabushan K., Manikandan

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In a swirl atomizer, fluid undergoes a swirling motion as a result of centrifugal force created by opposed tangential inlets in the swirl chamber. The angular momentum of fluid continually increases as it reaches the exit orifice and forms a hollow sheet. Which disintegrates to form ligaments and droplets respectively as it flows downstream. This type of atomizers used in rocket injectors and oil burner furnaces. In this present investigation a swirl atomizer with two opposed tangential inlets has been designed. Water as working fluid, experiments had been conducted for the fluid injection pressures in regime of 0.033 bar to 0.519 bar. The fluid has been pressured by a 0.5hp pump and regulated by a pressure regulator valve. Injection pressure of fluid has been measured by a U-tube mercury manometer. The spray pattern and the droplets has been captured with a high resolution camera in black background with a high intensity flash highlighting the fluid. The unprocessed images were processed in ImageJ processing software for measuring the droplet diameters and its shape characteristics along the downstream. The parameters such as mean droplet diameter and distribution, wave pattern, rupture distance and spray angle were studied for this atomizer. The above results were compared with theoretical results and also analysed for deviation with design parameters.

Keywords: swirl atomizer, injector, spray, SWIRL

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Authors: Millicent N. Khumalo, Phesheya E. Dlamini

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Shrub-encroachment leads to a gain or loss of soil organic carbon (SOC) in previously open rangelands. The stabilization mechanisms controlling the storage of soil organic carbon (SOC) within aggregates of shrub-encroached grassland soils are poorly understood, especially in shallow plinthic soils. In this study, physical fractionation of surface soils (0- 10 cm) collected from open and shrub-encroached grasslands was conducted to determine the distribution of SOC within macro-and- microaggregates. Soil aggregates were classified into four fractions by a wet-sieving procedure, namely >2000 (large macro-aggregates), 212-2000 (small macro-aggregates), 50-212 (microaggregates) and < 50µm (silt+clay). In both shrub-encroached and open grassland soils, SOC was greater in the silt+clay fraction. In this fraction, SOC was on average 133% greater in shrub-encroached compared to open grassland. The greater SOC within the silt+clay fraction is due to the greater surface area and thus more exchange sites for carbon absorption. This implies that the SOC physically protected within the silt+clay is stored long-term.

Keywords: aggregate fractions, shrub-encroachment, soil organic carbon, stabilization

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Authors: Maria M. Giannakou, Athanasios K. Ziliaskopoulos

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Transmission pipelines carrying natural gas are often routed through populated cities, industrial and environmentally sensitive areas. While the need for these networks is unquestionable, there are serious concerns about the risk these lifeline networks pose to the people, to their habitat and to the critical infrastructures, especially in view of natural disasters such as earthquakes. This work presents an Integrated Pipeline Risk Management methodology (IPRM) for assessing the hazard associated with a natural gas pipeline failure due to natural or manmade disasters. IPRM aims to optimize the allocation of the available resources to countermeasures in order to minimize the impacts of pipeline failure to humans, the environment, the infrastructure and the economic activity. A proposed knapsack mathematical programming formulation is introduced that optimally selects the proper mitigation policies based on the estimated cost – benefit ratios. The proposed model is demonstrated with a small numerical example. The vulnerability analysis of these pipelines and the quantification of consequences from such failures can be useful for natural gas industries on deciding which mitigation measures to implement on the existing pipeline networks with the minimum cost in an acceptable level of hazard.

Keywords: cost benefit analysis, knapsack problem, natural gas distribution network, risk management, risk mitigation

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Authors: Bridgette Merriman, Wen Fan

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Background: Existing cancer survivorship literature explores varying physical, psychosocial, and psychological late effects experienced by survivors of childhood cancer. However, adolescent and young adult (AYA) survivors of childhood cancer are understudied compared to their adult and pediatric cancer counterparts. Furthermore, existing quality of life (QoL) research fails to account for how cancer survivorship affects survivors across the lifespan. Given that prior research suggests positive cognitive appraisals of adverse events - such as cancer - mitigate detrimental psychosocial symptomologies later in life; it is crucial to understand cancer’s impacts on AYA survivors of childhood malignancies across the life course in order to best support these individuals and prevent maladaptive psychosocial outcomes. Methods: This qualitative study adopted the life-course perspective to investigate the experiences of AYA survivors of childhood malignancies. Eligible patients included AYA 21-30 years old who were diagnosed with cancer <18 years old and off active treatment for >2 years. Participants were recruited through social media posts. Study fulfillment included taking part in one semi-structured video interview to explore areas of survivorship previously identified as being specific to AYA survivors. Interviews were transcribed, coded, and analyzed in accordance with narrative analysis and life-course theory. This study was approved by the Boston College Institutional Review Board. Results: Of 28 individuals who met inclusion criteria and expressed interest in the study, nineteen participants (12 women, 7 men, mean age 25.4 years old) completed the study. Life course theory analysis revealed that events relating to childhood cancer are interconnected throughout the life course rather than isolated events. This “trail of survivorship” includes age at diagnosis, transitioning to life after cancer, and relationships with other childhood survivors. Despite variability in objective characteristics surrounding these events, participants recalled positive experiences regarding at least one checkpoint, ultimately finding positive meaning from their cancer experience. Conclusions: These findings suggest that favorable subjective experiences at these checkpoints are critical in fostering positive conceptions of childhood malignancy for AYA survivors of childhood cancer. Ultimately, healthcare professionals and communities may use these findings to guide support resources and interventions for childhood cancer patients and AYA survivors, therein minimizing detrimental psychosocial effects and maximizing resiliency.

Keywords: medical sociology, pediatric oncology, survivorship, qualitative, life course perspective

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Authors: Jesha Faye T. Librea, Leslie Joy L. Diaz

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Fuel-derived rice husk ash (fRHA) is a waste material from industries employing rice husk as a biomass fuel which, on the downside, causes disposal and environmental problems. To mitigate this, the fRHA was evaluated for use in other applications such as a pozzolanic material for the construction industry. In this study, the assessment of the potential of fRHA as pozzolanic supplementary cementitious material was conducted by determining the chemical and physical properties of fRHA according to ASTM C618, evaluating the fineness of the material according to ASTM C430, and determining its pozzolanic activity using Luxan Method. The material was found to have a high amorphous silica content of around 95.82 % with traces of alkaline and carbon impurities. The retained carbon residue is 7.18 %, which is within the limit of the specifications for natural pozzolans indicated in ASTM C618. The fineness of the fRHA is at 88.88 % retained at a 45-micron sieve, which, however, exceeded the limit of 34 %. This large particle size distribution was found to affect the pozzolanic activity of the fRHA. This was shown in the Luxan test, where the fRHA was identified as non-pozzolan due to its low pozzolanic activity index of 0.262. Thus, further processing must be done to the fRHA to pass the required ASTM fineness, have a higher pozzolanic activity index, and fully qualify as a pozzolanic material.

Keywords: rice husk ash, pozzolanic, fuel-derived ash, supplementary cementitious material

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Authors: Tomilola J. Ajayi

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A category of nanovalves system containing the α-cyclodextrin (α-CD) ring on a stalk tethered to the pores of mesoporous silica nanoparticles (MSN) is theoretically and computationally modelled. This functions to control opening and blocking of the MSN pores for efficient targeted drug release system. Modeling of the nanovalves is based on the interaction between α-CD and the stalk (p-anisidine) in relation to pH variation. Conformational analysis was carried out prior to the formation of the inclusion complex, to find the global minimum of both neutral and protonated stalk. B3LYP/6-311G**(d, p) basis set was employed to attain all theoretically possible conformers of the stalk. Six conformers were taken into considerations, and the dihedral angle (θ) around the reference atom (N17) of the p-anisidine stalk was scanned from 0° to 360° at 5° intervals. The most stable conformer was obtained at a dihedral angle of 85.3° and was fully optimized at B3LYP/6-311G**(d, p) level of theory. The most stable conformer obtained from conformational analysis was used as the starting structure to create the inclusion complexes. 9 complexes were formed by moving the neutral guest into the α-CD cavity along the Z-axis in 1 Å stepwise while keeping the distance between dummy atom and OMe oxygen atom on the stalk restricted. The dummy atom and the carbon atoms on α-CD structure were equally restricted for orientation A (see Scheme 1). The generated structures at each step were optimized with B3LYP/6-311G**(d, p) methods to determine their energy minima. Protonation of the nitrogen atom on the stalk occurs at acidic pH, leading to unsatisfactory host-guest interaction in the nanogate; hence there is dethreading. High required interaction energy and conformational change are theoretically established to drive the release of α-CD at a certain pH. The release was found to occur between pH 5-7 which agreed with reported experimental results. In this study, we applied the theoretical model for the prediction of the experimentally observed pH-responsive nanovalves which enables blocking, and opening of mesoporous silica nanoparticles pores for targeted drug release system. Our results show that two major factors are responsible for the cargo release at acidic pH. The higher interaction energy needed for the complex/nanovalve formation to exist after protonation as well as conformational change upon protonation are driving the release due to slight pH change from 5 to 7.

Keywords: nanovalves, nanogate, mesoporous silica nanoparticles, cargo

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Authors: Musadiq Idris, Sajjad Ali, Syed A. Khaliq, Umer Farooq

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Postmortem record of 217 captive ungulates including Black-buck (n=31), Chinkara (n=20), Hog deer (n=116), Spotted deer (n=35), Red Deer n=(04), and Rusa deer (n=11) submitted to the Veterinary Research Institute, Lahore, Pakistan was analyzed to determine the primary cause of mortality in these animals. The submissions included temporal distribution from Government wildlife captive farms, zoo, and private ownerships, over a three year period (2007-2009). The most common cause of death was found to be trauma (20.27%), followed by parasitic diseases (15.67%), bacterial diseases (11.98%), stillbirths (9.21%), snakebites (2.76%), gut affections (2.30%), neoplasia (1.38%) and starvation (0.92%). The exact cause of death could not be determined in 77 of 217 animals. Pneumonia (8.29%) and tuberculosis (3.69%) were the most common bacterial diseases. Analyses for parasitic infestation revealed tapeworms to be highest (11.05%), followed by roundworms (8.29%) and hemoparasitism (5.07%) (babesiosis and theileriosis). The mortality rate in young ungulates was lower as compared to adults (32.26% and 67.74%). Gender wise data presented higher mortality in females (55.30%) compared to males (44.70%). In conclusion, highest mortality factor in captive ungulates was trauma, followed by parasitic and bacterial infestations/infections of tapeworms and pneumonia, respectively. Furthermore, necropsies provided substantial information on etiology of death and other related epidemiological aspects.

Keywords: age, epidemiology, gender, mortality, ungulates

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Authors: Mohd Mudasir Shafi, Zafrul Hasan, Talat Saleem

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Information and communication Technology (ICT) services have been defined as a route to good governance. Introduction of ICT into Governance has given rise to the idea of e-governance which helps in enhancing transparency, generating accountability and responsiveness in the system in order to provide faster and quality service to the citizen. Advancement in ICT has provided governments all over the world to speed up the delivery of information and services to citizens and businesses and increase their participation in governance. There has been varying degree of success over the past decade into providing services to the citizens using internet and different web services. These e-government initiatives have been extensively researched. Our research is aimed at the transition from electronic government to mobile government (m-government) initiatives implementing the mobile services and concerned to understand the major factors which will aid to adoption and distribution of these services. There must be some amount of research done in the integration process between e-government and m-government. There must also be enough amount of investigation done all the factors that could affect the transition process. Such factors differ between different places and the advancement in information and technology available there. In this paper, we have discussed why mobile communication system can be used for effective e-governance and the areas where m-governance can be implemented. The paper will examine some of the reasons as well as the main opportunities for improving effective governance through mobile phones.

Keywords: e-governance, mobile phones, information technology, m-government

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Authors: Abdul Latif Shaikh, Osama Kattos

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Purpose: The study compared the effects of intra and inter group short duration intensity training and long duration steady state-run training on the cardiovascular performance on female athletes. Method: Twenty trained young female athletes age between 17 to 20 years were randomly selected to participate in the test. The sprint interval training (n-10) program consisted of 5 min sprints and steady state run (n-10) conducted for 30 min. Both groups completed eight sessions of training within four weeks. Result: In intragroup distribution of mean % change in all the variables from week 4 to week 1 did not differ significantly (p-value > 0.05). The inter-group means value of post resting heart rate, max oxygen consumption (VO2max), and calorie expenditure in sprint interval training was higher with compared with steady state run. Conclusion: The comparative mean value of the intergroups program concludes that the SIT program is superior to SSR in performance-based variables in trained young females. The SIT program can be applied as a time-efficient program for improving performance.

Keywords: calorie expenditure, maximum rate of oxygen consumption, post recovery HR (1-4-7 min), time domain

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Authors: Medha Talpade, Salil Talpade

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The intent of this quantitative project was to compare the values and perceptions of students from a predominantly white college (PWI) to those from a historically black college (HBCU) about culturally relevant teaching and learning practices in the academic realm. The reason for interrelating student culture with teaching practices is to enable a pedagogical response to the low retention rates of African American students and first generation Caucasian students in high schools, colleges, and their low rates of social mobility and educational achievement. Culturally relevant pedagogy, according to related research, is deemed rewarding to students, teachers, the local and national community. Critical race theory (CRT) is the main framework used in this project to explain the ubiquity of a culturally relevant pedagogy. The purpose of this quantitative study was to test the critical race theory that relates the presence of the factors associated with culturally relevant teaching strategies with perceived relevance. The culturally relevant teaching strategies were identified based on the recommendations and findings of past research. Participants in this study included approximately 145 students from a HBCU and 55 students from the PWI. A survey consisting of 37 items related to culturally relevant pedagogy was administered. The themes used to construct the items were: Use of culturally-specific examples in class whenever possible; use of culturally-specific presentational models, use of relational reinforcers, and active engagement. All the items had a likert-type response scale. Participants reported their degree of agreement (5-point scale ranging from strongly disagree to strongly agree) and importance (3-point scale ranging from not at all important to very important) with each survey item. A new variable, Relevance was formed based on the multiplicative function of importance and presence of a teaching and learning strategy. A set of six demographic questions were included in the survey. A consent form based on NIH and APA ethical standards was distributed prior to survey administration to the volunteers. Results of a Factor Analyses on the data from the PWI and the HBCU, and a ANOVA indicated significant differences on ‘Relevance’ related to specific themes. Results of this study are expected to inform educational practices and improve teaching and learning outcomes.

Keywords: culturally relevant pedagogy, college students, cross-cultural, applied psychology

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Authors: V. Keim, J. Spachtholz, J. Hammer

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The importance of fibre reinforced plastics continually increases due to the excellent mechanical properties, low material and manufacturing costs combined with significant weight reduction. Today, components are usually designed and calculated numerically by using finite element methods (FEM) to avoid expensive laboratory tests. These programs are based on material models including material specific deformation characteristics. In this research project, material models for short glass fibre reinforced plastics are presented to simulate the visco-elasto-plastic deformation behaviour. Prior to modelling specimens of the material EMS Grivory HTV-5H1, consisting of a Polyphthalamide matrix reinforced by 50wt.-% of short glass fibres, are characterized experimentally in terms of the highly time dependent deformation behaviour of the matrix material. To minimize the experimental effort, the cyclic deformation behaviour under tensile and compressive loading (R = −1) is characterized by isothermal complex low cycle fatigue (CLCF) tests. Combining cycles under two strain amplitudes and strain rates within three orders of magnitude and relaxation intervals into one experiment the visco-elastic deformation is characterized. To identify visco-plastic deformation monotonous tensile tests either displacement controlled or strain controlled (CERT) are compared. All relevant modelling parameters for this complex superposition of simultaneously varying mechanical loadings are quantified by these experiments. Subsequently, two different material models are compared with respect to their accuracy describing the visco-elasto-plastic deformation behaviour. First, based on Chaboche an extended 12 parameter model (EVP-KV2) is used to model cyclic visco-elasto-plasticity at two time scales. The parameters of the model including a total separation of elastic and plastic deformation are obtained by computational optimization using an evolutionary algorithm based on a fitness function called genetic algorithm. Second, the 12 parameter visco-elasto-plastic material model by Launay is used. In detail, the model contains a different type of a flow function based on the definition of the visco-plastic deformation as a part of the overall deformation. The accuracy of the models is verified by corresponding experimental LCF testing.

Keywords: complex low cycle fatigue, material modelling, short glass fibre reinforced polyphthalamides, visco-elasto-plastic deformation

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Authors: Aminu Musa Muhammad, Muhammad Kabiru Abubakar

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Monthly changes in Phytoplankton periodicity, nutrient levels, temperature, pH, suspended solids, dissolved solids, conductivity, dissolved oxygen and biochemical oxygen demand of Kazaure Dam, Jigawa State, Nigeria were studied for a period of six months (July-Dec.-2011). Physico-chemical result showed that temperature and pH ranged between17-25˚C and 5.5-7.5, while dissolved solids and suspended solids ranged between 95-155 mg/L and 0.13-112 mg/L respectively. Dissolved oxygen (DO), Biochemical oxygen demand (BOD), Chemical oxygen demand (COD), conductivity, nitrate, phosphate and sulphate ion concentrations were within the ranges of 3.5-3.6 mg/L, 4.8-7.2 mg/L, 8.10-12.30 mg/L, 21-58µΩ/cm, 0.2-8.1 mg/L, 2.4-18.1 mg/L, and 1.22-15.60 mg/L respectively. A total of 4514 Org/L phytoplankton were recorded, of which four classes of algae were identified. These comprised of Chlorophyta (44.1%), Cyanophyta(30.62%), Bacillariophyta(3.2%), Euglenophyta (32.1%). Descriptive statistics of the result showed that phytoplankton count varied with variation of physico-chemical parameters at 5% level during the study period. The abundance and distribution of the algae varied with the variation in the physico-chemical parameters. Pearson correlation showed that temperature and nutrients were significantly correlated with phytoplankton, while DO, sulphate and pH were insignificantly correlated, while there was no significant correlation with COD and phytoplankton.

Keywords: correlation, phytoplankton, physico chemical, kazaure dam

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Authors: Mahmoud Fouad, Mervat Badr, Marwa Ibrahim

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Micro-grid system is presently considered a reliable solution for the expected deficiency in the power required from future power systems. Renewable power sources such as wind, solar and hydro offer high potential of benign power for future micro-grid systems. Micro-Grid (MG) is basically a low voltage (LV) or medium voltage (MV) distribution network which consists of a number of called distributed generators (DG’s); micro-sources such as photovoltaic array, fuel cell, wind turbine etc. energy storage systems and loads; operating as a single controllable system, that could be operated in both grid-connected and islanded mode. The capacity of the DG’s is sufficient to support all; or most, of the load connected to the micro-grid. This paper presents a micro-grid system based on wind and solar power sources and addresses issues related to operation, control, and stability of the system. Using Matlab/Simulink, the system is modeled and simulated to identify the relevant technical issues involved in the operation of a micro-grid system based on renewable power generation units.

Keywords: micro-grid system, photovoltaic, wind turbine, energy storage, distributed generation, modeling

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Authors: Artur Tyliszczak, Ewa Szymanek, Maciej Marek

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Flow through granular materials is important to a vast array of industries, for instance in construction industry where granular layers are used for bulkheads and isolators, in chemical engineering and catalytic reactors where large surfaces of packed granular beds intensify chemical reactions, or in energy production systems, where granulates are promising materials for heat storage and heat transfer media. Despite the common usage of granulates and extensive research performed in this field, phenomena occurring between granular solid elements or between solids and fluid are still not fully understood. In the present work we analyze the heat exchange process between the flowing medium (gas, liquid) and solid material inside the granular layers. We consider them as a composite of isolated solid elements and inter-granular spaces in which a gas or liquid can flow. The structure of the layer is controlled by shapes of particular granular elements (e.g., spheres, cylinders, cubes, Raschig rings), its spatial distribution or effective characteristic dimension (total volume or surface area). We will analyze to what extent alteration of these parameters influences on flow characteristics (turbulent intensity, mixing efficiency, heat transfer) inside the layer and behind it. Analysis of flow inside granular layers is very complicated because the use of classical experimental techniques (LDA, PIV, fibber probes) inside the layers is practically impossible, whereas the use of probes (e.g. thermocouples, Pitot tubes) requires drilling of holes inside the solid material. Hence, measurements of the flow inside granular layers are usually performed using for instance advanced X-ray tomography. In this respect, theoretical or numerical analyses of flow inside granulates seem crucial. Application of discrete element methods in combination with the classical finite volume/finite difference approaches is problematic as a mesh generation process for complex granular material can be very arduous. A good alternative for simulation of flow in complex domains is an immersed boundary-volume penalization (IB-VP) in which the computational meshes have simple Cartesian structure and impact of solid objects on the fluid is mimicked by source terms added to the Navier-Stokes and energy equations. The present paper focuses on application of the IB-VP method combined with large eddy simulation (LES). The flow solver used in this work is a high-order code (SAILOR), which was used previously in various studies, including laminar/turbulent transition in free flows and also for flows in wavy channels, wavy pipes and over various shape obstacles. In these cases a formal order of approximation turned out to be in between 1 and 2, depending on the test case. The current research concentrates on analyses of the flows in dense granular layers with elements distributed in a deterministic regular manner and validation of the results obtained using LES-IB method and body-fitted approach. The comparisons are very promising and show very good agreement. It is found that the size, number of elements and their distribution have huge impact on the obtained results. Ordering of the granular elements (or lack of it) affects both the pressure drop and efficiency of the heat transfer as it significantly changes mixing process.

Keywords: granular layers, heat transfer, immersed boundary method, numerical simulations

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Authors: Elena M. Kopteva, Pavlina Jaluvkova, Zdenek Stuchlik

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The question of constructing a consistent model of the cosmological black hole remains to be unsolved and still attracts the interest of cosmologists as far as it is important in a wide set of research problems including the problem of the black hole horizon dynamics, the problem of interplay between cosmological expansion and local gravity, the problem of structure formation in the early universe etc. In this work, the model of the cosmological black hole is built on the basis of the exact solution of the Einstein equations for the spherically symmetric inhomogeneous dust distribution in the approach of the mass function use. Possible trajectories for massive particles and photons near the black hole immersed in the nonstatic dust cosmological background are investigated in frame of the obtained model. The reference system of distant galaxy comoving to cosmological expansion combined with curvature coordinates is used, so that the resulting metric becomes nondiagonal and involves both proper ‘cosmological’ time and curvature spatial coordinates. For this metric the geodesic equations are analyzed for the test particles and photons, and the respective trajectories are built.

Keywords: exact solutions for Einstein equations, Lemaitre-Tolman-Bondi solution, cosmological black holes, particle and photon trajectories

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Authors: Charles-Olivier Amédée-Manesme, Benoit Faye, Eric Le Fur

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In this paper, the heterogeneity of the Bordeaux Legends 50 wine market price segment is addressed. For this purpose, quantile regression is applied – with market segmentation based on wine bottle price quantile – and the hedonic price of wine attributes is computed for various price segments of the market. The approach is applied to a major privately held data set which consists of approximately 30,000 transactions over the 2003–2014 period. The findings suggest that the relative hedonic prices of several wine attributes differ significantly among deciles. In particular, the elasticity coefficient of the expert ratings shows strong variation among prices. If - as suggested in the literature - expert ratings have a positive influence on wine price on average, they have a clearly decreasing impact over the quantiles. Finally, the lower the wine price, the higher the potential for price appreciation over time. Other variables such as chateaux or vintage are also shown to vary across the distribution of wine prices. While enhancing our understanding of the complex market dynamics that underlie Bordeaux wines’ price, this research provides empirical evidence that the QR approach adequately captures heterogeneity among wine price ranges, which simultaneously applies to wine stock, vintage and auctions’ house.

Keywords: hedonics, market segmentation, quantile regression, heterogeneity, wine economics

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Authors: Denise F. Brown, Melina McConatha

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African Americans utilizing the art of vocal expressions, particularly for self-expression, has been a historical avenue of advocating for social justice and human rights. Vocal expressions can take many forms, such as singing, poetry, storytelling, and acting. Many well-known artists, politicians, leaders, and teachers used their voices to promote the causes and concerns of the African American community as well as the expression of their own experiences of being 'black' in America. The purpose of this project was to evaluate the perceptions of African American students in utilizing their voices for self-awareness, interview skills, and social change after attending a three-part workshop on vocal advocacy. This research utilized the framework of black feminism to understand empowerment in advocacy and self-expression. Students participated in learning about the power of their voices, and what purpose presence, and passion they discovered through the Immersive Voice workshop. There were three areas covered in the workshop. The first area was the power of the voice, the second area was the application of vocal passion, and the third area was applying the vocal power to express personal interest, interests of advocating for others, and confidence and speaking to others to further careers, i.e., using vocal power for job interviewing skills. The students were instructed to prepare for the workshops by completing a pre-workshop open-ended survey. There were a total of 15 students that participated. After the workshop ended, the students were instructed to complete a post-workshop survey. The surveys were assessed by evaluating both themes and codes from student's written feedback. From the pre-workshop survey, students were given a survey for them to provide feedback regarding the power of voice prior to participating in the workshops. From the student's responses, the theme (advocating for self and others) emerged as it related to student's feedback on what it means to advocate. There were three codes that led to the theme, having knowledge about advocating for self and others, gaining knowledge to advocate for self and others, and using that knowledge to advocate for self and others. After the students completed participation in the workshops, a post workshop- survey was given to the students. Students' feedback was assessed, and the same theme emerged, 'advocating for self and others.' The codes related to the theme, however, were different and included using vocal power (a term students learned during the workshop) to represent self, represent others, and obtain a job/career. In conclusion, the results of the survey showed that students still perceived advocating as speaking up for themselves and other people. After the workshop, students still continued to associate advocacy with helping themselves and helping others but were able to be more specific about how the sound of their voice could help in advocating, and how they could use their voice to represent themselves in getting a job or starting a career.

Keywords: advocacy, command, self-expression, voice

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Authors: Lin Dong-Yih, Yang S. M., Huang B. W., Lian J. A.

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Super duplex stainless steel has excellent mechanical properties and corrosion resistance. It becomes important structural material as its application has been extended to the fields such as renewable energy and the chemical industry because of its excellent properties. As examples are offshore wind power, solar cell machinery, and pipes in the chemical industry. The mechanical properties and corrosion resistance of super duplex stainless steel can be eliminated by welding due to the precipitation of the hard and brittle σ phase, which is rich of chromium, and molybdenum elements. This paper studies the influence of carbon element on the phase transformation of -ferrite and σ phase in 2507 super duplex stainless steel. The 2507 will be under argon gas protection welded with 316 and 316L extra low carbon stainless steel separately. The microstructural phases of stainless steels before and after welding, in fusion, heat affected zones, and base material will be studied via X-ray, OM, SEM, EPMA i.e. their quantity, size, distribution, and morphology. The influences of diffusion by carbon element will be compared according to the microstructures, hardness, and corrosion tests.

Keywords: complex stainless steel, welding, phase formation, carbon element, sigma phase, delta ferrite

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Authors: Ratnakar Mahajan, Matteo Lelli, Kinjal Parmar

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Ground improvement is a very important aspect of infrastructure development, especially when it comes to deep-ground improvement. The use of various geosynthetic applications is very common these days for ground improvement. This paper presents a case study where the combination of two geosynthetic applications was used in order to optimize the design as well as to control the settlements through uniform load distribution. The Agartala-Akaura rail project was made to help increase railway connectivity between India and Bangladesh. Both countries have started the construction of the same. The project requires high railway embankments to be built for the rail link. However, the challenge was to design a proper ground improvement solution as the entire area comprises very soft soil for an average depth of 15m. After due diligence, a combination of two methods was worked out by Maccaferri. PVDs were provided for the consolidation, and on top of that, a layer of high-strength geogrids (Paralink) was proposed as a basal reinforcement. The design approach was followed as described in Indian standards as well as British standards. By introducing a basal reinforcement, the spacing of PVDs could be increased, which allowed quick installation and less material consumption while keeping the consolidation time within the project duration.

Keywords: ground improvement, basal reinforcement, PVDs, high strength geogrids, Paralink

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Authors: M. Dahbi, M. Sellam, A. Benatiallah, A. Harrouz

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The wind energy is one of the most significant and rapidly developing renewable energy sources in the world and it provides a clean energy resource, which is a promising alternative in the short term in Algeria The main purpose of this paper is to compared and discuss the wind power potential in three sites located in sahara of Algeria (south west of Algeria) and to perform an investigation on the wind power potential of desert of Algeria. In this comparative, wind speed frequency distributions data obtained from the web site SODA.com are used to calculate the average wind speed and the available wind power. The Weibull density function has been used to estimate the monthly power wind density and to determine the characteristics of monthly parameters of Weibull for these three sites. The annual energy produced by the BWC XL.1 1KW wind machine is obtained and compared. The analysis shows that in the south west of Algeria, at 10 m height, the available wind power was found to vary between 136.59 W/m2 and 231.04 W/m2. The highest potential wind power was found at Adrar, with 21h per day and the mean wind speed is above 6 m/s. Besides, it is found that the annual wind energy generated by that machine lie between 512 KWh and 1643.2 kWh. However, the wind resource appears to be suitable for power production on the sahara and it could provide a viable substitute to diesel oil for irrigation pumps and rural electricity generation.

Keywords: Weibull distribution, parameters of Wiebull, wind energy, wind turbine, operating hours

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Authors: Karthik Chamari, Vasudha Rudraraju, Gaurav Chaudhari

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Background: Mantle cell lymphoma (MCL) is one of the mature B cell non-Hodgkin lymphomas (NHL). The course of MCL is moderately aggressive and variable, and it has median overall survival of 8 to 10 years. Ibrutinib, a Bruton’s tyrosine kinase inhibitor, was approved by the United States (US) Food and Drug Administration in November of 2013 for the treatment of MCL patients who have received at least one prior therapy. In this study, we aimed to evaluate whether there has been a change in survival and patterns of second primary malignancies (SPMs) among the MCL population in the US after ibrutinib approval. Methods: Using the National Cancer Institute’s Surveillance, Epidemiology, and End Results (SEER)-18, we conducted a retrospective study with patients diagnosed with MCL (ICD-0-3 code 9673/3) between 2007 and 2018. We divided patients into two six-year cohorts, pre-ibrutinib approval (2007-2012) and post-ibrutinib approval (2013-2018), and compared relative survival rates (RSRs) and standardized incidence ratios (SIRs) of SPMs between cohorts. Results: We included 9,257 patients diagnosed with MCL between 2007 and 2018 in the SEER-18 survival and SIR registries. Of these, 4,205 (45%) patients were included in the pre-ibrutinib cohort, and 5052 (55%) patients were included in the post-ibrutinib cohort. The median follow-up duration for the pre-ibrutinib cohort was 54 months (range 0 to 143 months), and the post-ibrutinib cohort was 20 months (range 0 to 71 months). There was a significant difference in the five-year RSRs between pre-ibrutinib and post-ibrutinib cohorts (57.5% vs. 62.6%, p < 0.005). Out of the 9,257 patients diagnosed with MCL, 920 developed SPMs. A higher proportion of SPMs occurred in the post-ibrutinib cohort (63%) when compared with the pre-ibrutinib cohort (37%). Non-hematological malignancies comprised most of all SPMs. A higher incidence of non-hematological malignancies occurred in the post-ibrutinib cohort (SIR 1.42, 95% CI 1.29 to 1.56) when compared with the pre-ibrutinib cohort (SIR 1.14, 95% CI 1 to 1.3). There was a statistically significant increase in the incidence of cancers of the respiratory tract (SIR 1.77, 95% CI 1.43 to 2.18), urinary tract (SIR 1.61, 95% CI 1.23 to 2.06) when compared with other non-hematological malignancies in post-ibrutinib cohort. Conclusions: Our study results suggest the relative survival rates have increased since the approval of ibrutinib for mantle cell lymphoma patients. Additionally, for some unclear reasons, the incidence of SPM’s (non-hematological malignancies), mainly cancers of the respiratory tract, urinary tract, have increased in the six years following the approval of ibrutinib. Further studies should be conducted to determine the cause of these findings.

Keywords: mantle cell lymphoma, Ibrutinib, relative survival analysis, secondary primary cancers

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Authors: Polycarpe Feussi

Abstract:

Globalization, technological and customer increasing changes, amongst other drivers, result in higher levels of uncertainty and unpredictability for organizations. In order for organizations to cope with the uncertain and fast-changing economic and business environment, these organizations need to innovate in order to achieve flexibility. In simple terms, the organizations must develop strategies leading to the ability of these organizations to provide horizontal information connections across the supply chain to create and deliver products that meet customer needs by synchronization of customer demands with product creation. The generated information will create efficiency and effectiveness throughout the whole supply chain regarding production, storage, and distribution, as well as eliminating redundant activities and reduction in response time. In an integrated supply chain, spanning activities include coordination with distributors and suppliers. This paper explains how through postponement strategies, flexibility can be achieved in an organization. In order to achieve the above, a thorough literature review was conducted via the search of online websites that contains material from scientific journal data-bases, articles, and textbooks on the subject of postponement and flexibility. The findings of the research are found in the last part of the paper. The first part introduces the concept of postponement and its importance in supply chain management. The second part of the paper provides the methodology used in the process of writing the paper.

Keywords: postponement strategies, supply chain management, flexibility, logistics

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Authors: Jinliang Yuan, Jong-Sung Yu, Bengt Sundén

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A computational fluid dynamics (CFD) model is developed for rechargeable non-aqueous electrolyte lithium-air batteries with a partial opening for oxygen supply to the cathode. Multi-phase transport phenomena occurred in the battery are considered, including dissolved lithium ions and oxygen gas in the liquid electrolyte, solid-phase electron transfer in the porous functional materials and liquid-phase charge transport in the electrolyte. These transport processes are coupled with the electrochemical reactions at the active surfaces, and effects of discharge reaction-generated solid Li2O2 on the transport properties and the electrochemical reaction rate are evaluated and implemented in the model. The predicted results are discussed and analyzed in terms of the spatial and transient distribution of various parameters, such as local oxygen concentration, reaction rate, variable solid Li2O2 volume fraction and porosity, as well as the effective diffusion coefficients. It is found that the effect of the solid Li2O2 product deposited at the solid active surfaces is significant on the transport phenomena and the overall battery performance.

Keywords: Computational Fluid Dynamics (CFD), modeling, multi-phase, transport phenomena, lithium-air battery

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Authors: Hamid Ahmadi, Shadi Asoodeh

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The fatigue life of tubular joints commonly found in offshore industry is not only dependent on the value of hot-spot stress (HSS), but is also significantly influenced by the through-the-thickness stress distribution characterized by the degree of bending (DoB). The determination of DoB values in a tubular joint is essential for improving the accuracy of fatigue life estimation using the stress-life (S–N) method and particularly for predicting the fatigue crack growth based on the fracture mechanics (FM) approach. In the present paper, data extracted from finite element (FE) analyses of tubular KT-joints, verified against experimental data and parametric equations, was used to investigate the effects of geometrical parameters on DoB values at the crown 0˚, saddle, and crown 180˚ positions along the weld toe of central brace in tubular KT-joints subjected to axial loading. Parametric study was followed by a set of nonlinear regression analyses to derive DoB parametric formulas for the fatigue analysis of KT-joints under axial loads. The tubular KT-joint is a quite common joint type found in steel offshore structures. However, despite the crucial role of the DoB in evaluating the fatigue performance of tubular joints, this paper is the first attempt to study and formulate the DoB values in KT-joints.

Keywords: tubular KT-joint, fatigue, degree of bending (DoB), axial loading, parametric formula

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Authors: Raimi Abiodun Moronfolu, Anthonia Olusola Moronfolu

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The purpose of this study was to assess athlete’s preparation and quality of opponent as determinants of self-efficacy among university athletes in south-west Nigeria. The descriptive research method was employed in conducting the study. A total of 200 athletes, selected from 4 universities in South-West geopolitical zone of Nigeria through a stratified random sampling technique, were used in the study. The instrument used for data collection was a self-structured questionnaire named ‘Athletes Self-Efficacy Assessment Questionnaire (ASAQ)’. This was developed by the researchers and face validated by three experts in sports psychology. The test-retest method was used in establishing the reliability of the instrument (r=0.79). A total of 200 copies of the validated ASAQ were administered on selected respondents using the spot method. The data collected was used to develop a frequency distribution table for analysis. The descriptive statistics of percentage was used in presenting the data collected, while inferential statistics of linear regression was used in drawing inferences at a 0.05 level of significance. The findings indicated that athlete’s preparation and quality of opponent were significant determinants of self-efficacy among university athletes in South-West Nigeria.

Keywords: athletes, preparation, opponent, self-efficacy

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Authors: Vineel Inampudi, Arjun Prakash, Joseph Vinod

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Aims and Objectives: To evaluate the interrater reliability in grading ASPECTS score, between emergency medicine physician at first contact and radiologist among patients with acute ischemic stroke. Materials and Methods: We conducted a retrospective analysis of 86 acute ischemic stroke cases referred to the Department of Radiodiagnosis during November 2014 to January 2016. The imaging (plain CT scan) was performed using GE Bright Speed Elite 16 Slice CT Scanner. ASPECTS score was calculated separately by an emergency medicine physician and radiologist. Interrater reliability for total and dichotomized ASPECTS (≥ 6 and < 6) scores were assessed using statistical analysis (ICC and Cohen ĸ coefficients) on SPSS software (v17.0). Results: Interrater agreement for total and dichotomized ASPECTS was substantial (ICC 0.79 and Cohen ĸ 0.68) between the emergency physician and radiologist. Mean difference in ASPECTS between the two readers was only 0.15 with standard deviation of 1.58. No proportionality bias was detected. Bland Altman plot was constructed to demonstrate the distribution of ASPECT differences between the two readers. Conclusion: Substantial interrater agreement was noted in grading ASPECTS between emergency medicine physician at first contact and radiologist thereby confirming its robustness even in a rural setting.

Keywords: ASPECTS, computed tomography, MCA territory, stroke

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Authors: Eldho Paul, Brijesh Paul

Abstract:

This work proposes an auction mechanism based solution methodology for the optimum scheduling of trucks in a cross-docking centre. The cross-docking centre is an important element of lean supply chain. It reduces the amount of storage and transportation costs in the distribution system compared to an ordinary warehouse. Better scheduling of trucks in a cross-docking center is the best way to reduce storage and transportation costs. Auction mechanism is commonly used for allocation of limited resources in different real-life applications. Here, we try to schedule inbound trucks by integrating auction mechanism with the functioning of a cross-docking centre. A mathematical model is developed for the optimal scheduling of inbound trucks based on the auction methodology. The determination of exact solution for problems involving large number of trucks was found to be computationally difficult, and hence a genetic algorithm based heuristic methodology is proposed in this work. A comparative study of exact and heuristic solutions is done using five classes of data sets. It is observed from the study that the auction-based mechanism is capable of providing good solutions to scheduling problem in cross-docking centres.

Keywords: auction mechanism, cross-docking centre, genetic algorithm, scheduling of trucks

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Authors: Arjun Paul, Adrijit Goswami

Abstract:

In our present work, an economic order quantity inventory model with shortages is developed where holding cost is expressed as linearly increasing function of time and demand rate is a ramp type function of time. The items considered in the model are deteriorating in nature so that a small fraction of the items is depleted with the passage of time. In order to consider a more realistic situation, the deterioration rate is assumed to follow a continuous uniform distribution with the parameters involved being triangular fuzzy numbers. The inventory manager offers his customer a discount in case he is willing to backorder his demand when there is a stock-out. The optimum ordering policy and the optimum discount offered for each backorder are determined by minimizing the total cost in a replenishment interval. For better illustration of our proposed model in both the crisp and fuzzy sense and for providing richer insights, a numerical example is cited to exemplify the policy and to analyze the sensitivity of the model parameters.

Keywords: fuzzy deterioration rate, price discount on backorder, ramp type demand, shortage, time varying holding cost

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Authors: Ode Kenneth Ogbu

Abstract:

This study was designed as a survey to investigate the incidence of use and abuse of drug as a social problem among the Nigeria youths in the secondary schools in urban centres of Benue state. 500 SS 3 and fresh secondary school graduates in remedial science class of Benue State University Makurdi with mean age of 16.8 were randomly sampled for the study. An instrument called drug use and abuse perception questionnaire (DAPQ) with a reliability coefficient of 74 were administered to the students. Only 337 copies of the questionnaire were properly completed and returned which reduced the sample size of 337. The data were subjected to factor analysis. X2 statistic and frequency distribution using split half method. The result of the analysis showed that: the DAPQ yield seven baseline factors responsible for drug use and abuse; there was appreciable evidence that the study subjects used drugs (42.1%); alcohol topped the list of the drugs consumed; most students use their pocket money to buy drugs; drugs were purchased from unconventional, hidden places and 13 out of the 20 items of DAPQ were perceived as significant factors in drug use and abuse. The paper recommends proper intervention of government, parents and NGO’S among students to reduce cases of drug abuse.

Keywords: drug abuse, psychology, psychiatry, students

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Authors: Andy Obinna Ibeje

Abstract:

In this study, the erodibility indices and some soil properties of some cassava farms in selected areas of Abia and Imo States were investigated. This study involves taking measurements of some soil parameters such as permeability, soil texture and particle size analysis from which the erodibility indices were compared. Results showed that soils of the areas are very sandy. The results showed that Isiukwuato with index of 72 has the highest erodibility index. The results also showed that Arondizuogu with index of 34 has the least erodibility index. The results revealed that soil erodibility (k) values varied from 34 to 72. Nkporo has the highest sand content; Inyishie has the least silt content. The result indicates that there were respectively strong inverse relationship between clay and silt contents and erodibility index. On the other hand, sand, organic matter and moisture contents as well as soil permeability has significantly high positive correlation with soil erodibility and it can be concluded that particle size distribution is a major finger print on the erodibility index of soil in the study area. It is recommended that safe cultural practices like crop rotation, matching and adoption of organic farming techniques be incorporated into farming communities of Abia and Imo States in order to stem the advances of erosion in the study area.

Keywords: erodibility, indices, soil, sand

Procedia PDF Downloads 349