Effects of Rotation on Turbulence Production

Authors: Alan S. Hsieh, Sedat Biringen

ABSTRACT
Direct numerical simulations (DNS) of non-rotating and rotating turbulent channel flow were conducted. The data base obtained from these DNS simulations was used to investigate the prominent coherent structures involved in the turbulence generation cycle. Predictions from three theoretical models concerning the formation and evolution of sublayer streaks, three-dimensional hairpin vortices and propagating plane waves were validated using visualizations from the present DNS data. Quadrant analysis was used to determine a phase shift between the fluctuating streamwise and wall-normal velocities as a characteristic of turbulence production in the suction region at a low rotation number.

Source:

Journal: Journal of Applied Mathematics and Physics
DOI: 10.4236/jamp.2019.72024

(PDF)
Paper Id: 90495 (metadata)

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Determination of Copper Price Expectations in the International Market: Some Important Variables

Authors: Andre Assis de Salles*orcid, Raphael Sebastian Magrath,
Matheus Manzani Malheiros

ABSTRACT
The purpose of this work is to identify variables that are relevant to the copper price setting in the international market. Thus statistical hypothesis tests and statistical tools that help to identify historical relevance and to measuring the intensity of the impact of each variable on the copper price on several time horizons was applied. At the end, a regression model that aims to assess the combined effect of the considered time series was estimated. The global industrial production and the aluminum price showed the greatest evidences of being relevant to the copper price. The results suggest that copper stocks, foreign exchange rates and crude oil price should also be considered.

Source:

Journal: Open Journal of Business and Management
DOI: 10.4236/ojbm.2019.72024(PDF)
Paper Id: 90465 (metadata)

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Optimization of Municipal Solid Waste Management of Bins Using GIS. A Case Study: Nuseirat City

Authors: Maher A. El-Hallaq, Rami Mosabeh

ABSTRACT
Solid Waste Management, SWM, is an integral part of public health and environmental control. Improper SWM leads to both economic and environmental sufferings. Almost all factors related to solid waste management have both spatial and non-spatial components. Thus, traditional ways of storing and analyzing data keep data in an isolated form, which results in an inefficient management system. This research aims to optimize municipal solid waste management of bins using GIS. Nuseirat City is chosen as a case study to evaluate SWM of recycle bins to allow the collection process to get less cost and less time as well as to determine the best routes for the trucks to collect the bins. Using Location-Allocation technique, the study indicates that 50 bins from the existing 222 bins do not meet the required selection criteria and need to be re-distributed. It also shows that there are many areas which are not serviced and that the existing bins do not cover all areas in Nuseirat. Nuseirat municipality needs to supply 173 bins besides the existing bins in order to fully cover the city. Moreover, the best tracks to be followed by vehicles that will reduce the financial cost using Vehicle Routing Problem Analysis are determined using GIS network analysis. It is recommended the use of GIS in the administration, especially the management of solid waste and the consideration of it mainly in the general system of municipalities working in the Gaza Strip. Extensive attention should be focused on the collection of solid waste because it is important in the development of cities and it gives a wonderful cultural landscape.

Source:

Journal: Journal of Geographic Information System
DOI: 10.4236/jgis.2019.111003

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Paper Id: 90458 (metadata)

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Determination and Validation of HPTLC Method for Cinacalcet Hydrochloride

Authors:Swetha Kamatham, Ciddi Veeresham

ABSTRACT
Cinacalcet Hydrochloride (CIN) is a new calcimimetic agent indicated for the use in hypercalcemia. The present work is aimed at development and validation of a novel and simple high-performance thin-layer chromatographic (HPTLC) method for the analysis of Cinacalcet Hydrochloride (active pharmaceutical ingredient, API. In the method, Aluminum-backed silica gel 60 F254 plates (10 × 10 cm) were used as stationary phase and chloroform: acetonitrile (6:4, v/v) as the mobile phase, which showed compact bands of Cinacalcet HCl (RF 0.30 ± 0.02). Quantitative analysis was carried out by densitometry at a wavelength of 282 nm. Linear regression analysis for the calibration spots showed good correlation ship with regression co-efficient r2 = 0.9994 in the range of 40 – 160 ng/band. The developed method suitability for quantification of CIN was learned by validating it as per the ICH guidelines. CIN detection limit was 0.48 ng/band and the quantification limit was 1.59 ng/band. The proposed method was found to be linear (r2 = 0.999), precise (%RSD < 2% for intraday and intermediate precision), accurate, specific, and robust. Further, the developed method was validated and found suitable for stress induced studies, since presence of degradants has no effect on CIN estimation. The proposed method was found to be simple, sensitive, precise, accurate and reproducible for the estimation of CIN.

Source:

Journal: American Journal of Analytical Chemistry
DOI: 10.4236/ajac.2019.102005(PDF)
Paper Id: 90449 (metadata)

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Antibiotic Sensitivity Patterns of Urine and Biofilms in Patients with Indwelling Urinary Catheter in Denden Hospital, Asmara, Eritrea

Authors: Lia Alem, Salih Mohammed, Mohammed Elfatih A. I. Humida,
Berzelin Adugna, Feven G. Medhin, Temesgen Weldu

ABSTRACT
The intricate infections leading to long-term morbidity of catheterized patients are due to the presence of a covering and blocking the lumen of urinary catheters by biofilms which have increased ability of resistance to host immune system and antibiotic treatment. The biofilm mode of growth is a basic survival strategy implemented by bacteria in a wide range of settings such as environmental, industrial and clinical aquatic settings. Bacterial growth on the inner surface of the catheter with biofilm formation is frequent and may occur within days of catheter placement. This study investigated the formation of biofilm inside catheter lumen of patients from Denden hospital, Asmara, Eritrea. And also, it assessed the antimicrobial sensitivity pattern of biofilm isolates and compared it with urine isolates. Resistance to antibiotics was observed in biofilm isolates more than urine isolates. E. coli was the most frequently isolated organism in both biofilm and urine samples.

Source:

Journal: Advances in Microbiology
DOI: 10.4236/aim.2019.92010(PDF)
Paper Id: 90444 (metadata)

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The Psychosocial Risks in Workplace as a Category in Research. Comparative Diagnosis

Author:Monika Budnik

ABSTRACT
Article presents the issue of psychosocial risks from perspective diversity on culture context. This context is socially appointed through the meanings by using and conceptualization notions, legitimizing these concepts of notion in the law and through studying phenomena through tools to adequately measure the scale of occurrence of a given psychosocial threat. The main idea of this article focuses on the social constructing concepts and definitions reproduced in the society through: using the notion of psychosocial hazards, different methods and research techniques in the social sciences themselves to explore these phenomena, the different scale of the declared occurrence of social threats to the culturally diverse dimensions of national cultures. Presented areas of psychosocial risks from European perspective, contain differentiated standards which are used in theory and research. Moreover the short article presents the diverse needs of measurement methods adequate for the broad frameworks of psychosocial risks such as mobbing, harcèlement moral, stress and presenteeism.

Source:

Journal: Open Journal of Social Sciences
DOI: 10.4236/jss.2019.72004(PDF)
Paper Id: 90423 (metadata)

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From Early Trade and Communication Networks to the Internet, the Internet of Things and the Global Intelligent Machine (GIM)

Author: Teun Koetsier

ABSTRACT
The present paper offers a sketch of the history of networks from the Stone Age until the present. I argue that man is a creator of networks, a homo reticulorum. Over the course of time more and more networks were created and they have become increasingly technologized. It seems inevitable that they will all be incorporated in the successor of the Internet of Things, the Global Intelligent Machine (GIM).

Source:

Journal: Advances in Historical Studies
DOI: 10.4236/ahs.2019.81001(PDF)
Paper Id: 90363 (metadata)

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Aquatic Ecosystem and Biodiversity: A Review

Authors: Sufia Irfan, Aishah Mohammed Motir Alatawi

ABSTRACT
Aquatic ecosystems support a substantial source of the earth’s biological diversity. They are an essential reservoir and share an enormous proportion of earth’s biological productivity. Both aquatic resources and its biodiversity are interrelated to each other and they perform a myriad of functions and are valuable and essential for the sustainability of biotic communities. Aquatic biodiversity in both freshwater and marine environments are under continuous decline because of overexploitation of species, introduced exotic plant or animal, pollution sources from cities, industries and agricultural zones, loss and changes in ecological niche. Their conservation and management in the form of bio reserve points and bioregional management and worldwide monitoring are needed for the protection of the aquatic biodiversity. This review is presenting information on biodiversity in aquatic habitats and their resources, in marine and fresh water ecosystems, their importance conservation and restoration mechanisms.

Source:

Journal: Open Journal of Ecology;
DOI: 10.4236/oje.2019.91001(PDF)
Paper Id:
90305 (metadata)

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Childhood Hearing Impairment, Gender, and Trait Neuroticism as Independent Predictors of the Occurrence of Hearing Problems in Adulthood

30Authors: Helen Cheng, Adrian Furnham

ABSTRACT
This study explored psychological, biomedical, and social factors in childhood and adulthood associated with the occurrence of self-reported hearing problems in adulthood. In total, 4828 participants with complete data on parental social class at birth, childhood hearing impairment measured at age 7 years and cognitive ability accessed at age 11 years, educational qualifications obtained at age 33 years, the Big-Five-Factor personality traits measured at age 50 years, current occupational levels and self-reported hearing problems at age 54 years were included in the study. Logistic regression analysis showed that among all the factors examined childhood hearing impairment and trait neuroticism as well as gender were the significant and independent predictors of hearing problems in adulthood.

Source:

Journal: Health
DOI: 10.4236/health.2019.111009(PDF)
Paper Id: 90284 (metadata)

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A Metamodel for Agile Requirements Engineering

Authors: Eva-Maria Schön1, Jorge Sedeño, Manuel Mejías, Jörg Thomaschewski, María José Escalona

ABSTRACT
Value delivery is becoming an important asset for an organization due to increasing competition in industry. Therefore, companies apply Agile Software Development (ASD) to be more competitive and reduce time to market. Using ASD for the development of systems implies that established approaches of Requirements Engineering (RE) undergo some changes in order to be more flexible to changing requirements. To this end, the field of agile RE is emergent and different process models for agile RE have arisen. The aim of this paper is to build an abstract layer about the variety of existing process models by means of a metamodel for agile RE. It has been created in several iterations and relies on the evaluation of related process models. Furthermore, we have derived process models for agile RE in industry by presenting instances of the metamodel in two different cases: one is based on Scrum whereas the other is based on Kanban. This paper contributes to the software development body of knowledge by delivering a metamodel for agile RE that supports researchers and practitioners modeling and improving their own process models. We can conclude that the agile RE metamodel is highly relevant for the industry as well as for the research community, since we have derived it following empirical research in the field of ASD.

Source:

Journal: Journal of Computer and Communications
DOI: 10.4236/jcc.2019.72001(PDF)
Paper Id: 90250 (metadata)

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