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2015

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Articles 9271 - 9300 of 9578

Full-Text Articles in Physical Sciences and Mathematics

Synthesis And Properties Of A Spinel Cathode Material For Lithium Ion Battery With Flat Potential Plateau, Ahmed Abdulrahman Ahmed Al-Tabbakh, Norlida Kamarulzaman, Aseel Al-Zubaidi Jan 2015

Synthesis And Properties Of A Spinel Cathode Material For Lithium Ion Battery With Flat Potential Plateau, Ahmed Abdulrahman Ahmed Al-Tabbakh, Norlida Kamarulzaman, Aseel Al-Zubaidi

Turkish Journal of Physics

A potential cathode material for lithium ion battery was synthesised by combustion reaction. The thermal behaviour of the as-synthesised precursor was measured using a thermogravimetric analyser and the range of calcination temperature from 500 $^{\circ}$C to 800 $^{\circ}$C was determined. X-ray diffraction analysis showed that all calcined powders crystallised in the cubic spinel structure of the $Fd\bar{3}m$ space group. The particle size distributions and morphologies of the powders were obtained using a particle size analyser and scanning electron microscope. The effect of calcination temperature on the electrochemical performance was investigated using galvanostatic charge/discharge measurements. The potential profiles of charge and …

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A Full Relativistic Treatment In Analyzing $\Alpha $-$^{12}$C And $\Alpha $-$^{40,42,44,48}$Ca Elastic Scattering Data At 1.37 Gev, Zuhair Fayyad Mahmoud Shehadeh Jan 2015

A Full Relativistic Treatment In Analyzing $\Alpha $-$^{12}$C And $\Alpha $-$^{40,42,44,48}$Ca Elastic Scattering Data At 1.37 Gev, Zuhair Fayyad Mahmoud Shehadeh

Turkish Journal of Physics

A simple optical potential of Woods-Saxon form is used within the framework of the Klein-Gordon equation, for the first time, to analyze the elastic differential cross sections for 1.37 GeV (lab) incident $\alpha $-particles on $^{12}$C and calcium isotopes $^{40,42,44,48}$Ca. The relativistic energy-momentum relation assures the need for relativistic calculations. As such, the previously determined parameters of all optical potential forms, used in the nonrelativistic Schrödinger equation and successfully analyzing the $\alpha $-$^{12}$C and $\alpha $-$^{40,42,44,48}$Ca data at 1.37 GeV, are to be revised. In the presence of Coulomb potential, as in the cases under consideration, the asymptotic solution of …

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Symmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Masssymmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Mass, Randy Wayne Jan 2015

Symmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Masssymmetry And The Order Of Events In Time: The Thermodynamics Of Blackbodies Composed Of Positive Or Negative Mass, Randy Wayne

Turkish Journal of Physics

I have previously proposed a discrete symmetry called CPM (charge-parity-mass) symmetry that defines matter as having positive mass and antimatter as having negative mass-both being involved in processes that proceed forward in time. I have generalized the second law of thermodynamics to describe and predict the order of events in time that take place in reversible thermodynamic systems composed of positive or negative mass. Here I extend the CPM symmetry to irreversible thermo-optical radiation systems characterized by the Stefan-Boltzmann law, Planck's blackbody radiation law, and Einstein's law of specific heat. The laws of radiation analyzed in terms of CPM symmetry …

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Crystal Dynamics Of Zinc Chalcogenides I: An Application To Znscrystal Dynamics Of Zinc Chalcogenides I: An Application To Zns, Jay Prakash Dubey, Raj Kishor Tiwari, Kripa Shankar Upadhyaya, Pramod Kumar Pandey Jan 2015

Crystal Dynamics Of Zinc Chalcogenides I: An Application To Znscrystal Dynamics Of Zinc Chalcogenides I: An Application To Zns, Jay Prakash Dubey, Raj Kishor Tiwari, Kripa Shankar Upadhyaya, Pramod Kumar Pandey

Turkish Journal of Physics

A van der Waals three body force rigid shell model (VTRSM) developed earlier for NaCl and CsCl structure was expanded by us for zinc blende structure (ZBS). This model includes the effect of three body interactions and van der Waals interactions in the rigid shell model where short-range interactions were considered up to the second neighbor. Our model thus developed was applied to study the phonon dispersion curves, Debye temperature variation, two phonon Raman/IR spectra, and anharmonic elastic properties of ZnS. Our results are in good agreement with the measured data wherever available.

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Multiwave Solutions Of Fractional 4th And 5th Order Burgers Equationsmultiwave Solutions Of Fractional 4th And 5th Order Burgers Equations, Emad A-B. Abdel-Salam, Gamal Fargahly Hassan Jan 2015

Multiwave Solutions Of Fractional 4th And 5th Order Burgers Equationsmultiwave Solutions Of Fractional 4th And 5th Order Burgers Equations, Emad A-B. Abdel-Salam, Gamal Fargahly Hassan

Turkish Journal of Physics

Fractional 4th and 5th order Burgers equations were studied by improving the generalized Exp-function method. The chief aim here was to discuss single-wave, double-wave, three-wave, and four-wave solutions for the space-time fractional (STF), time-fractional (TF), and space-fractional (SF) 4th and 5th order Burgers equations. The arbitrariness of the fractional orders allows much richer structures. It was observed that the wave amplitude of STF and SF Burgers equations is directly proportional to the noninteger derivative order, but the wave amplitude of TF Burgers equations is inversely proportional to the noninteger derivative order. From the graphical study of the obtained solution, a …

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Solution Processable Graphene Oxide Hole Transport Layers And Their Application In P3ht:Hhper Active Layer Based Bhjscsolution Processable Graphene Oxide Hole Transport Layers And Their Application In P3ht:Hhper Active Layer Based Bhjsc, Görkem Memi̇şoğlu, Hali̇de Di̇ker, Canan Varlikli Jan 2015

Solution Processable Graphene Oxide Hole Transport Layers And Their Application In P3ht:Hhper Active Layer Based Bhjscsolution Processable Graphene Oxide Hole Transport Layers And Their Application In P3ht:Hhper Active Layer Based Bhjsc, Görkem Memi̇şoğlu, Hali̇de Di̇ker, Canan Varlikli

Turkish Journal of Physics

Graphene oxide (GO) material was synthesized by an improved Hummers method and characterized by FT-IR, XPS, XRD, AFM, SEM, and UV-VIS analyses. The thickness of the GO layer was measured as 1.5 nm. Solution processed bulk heterojunction solar cells comprising poly(3-hexylthiophene) (P3HT) as the electron donor and N,N'-bis-2-(1-hydoxyhexyl)-3,4,9,10-perylenebis(dicarboximide) (HHPER) as the electron acceptor component of the active layer were produced with and without the GO doped PEDOT-PSS hole transport layers. The optical investigations of the active layer were performed by ground state absorption and photoluminescence measurements. Optimized blend w/w was determined as P3HT:HHPER, 3:1. It was found that the presence …

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Evaluation Of The Global Solar Irradiance In The Vhembe District Of Limpopo Province, South Africa, Using Different Theoretical Modelsevaluation Of The Global Solar Irradiance In The Vhembe District Of Limpopo Province, South Africa, Using Different Theoretical Models, Tshimangadzo Sophie Mulaudzi, Nnditshedzeni Eric Maluta, Vaith Sankaran Jan 2015

Evaluation Of The Global Solar Irradiance In The Vhembe District Of Limpopo Province, South Africa, Using Different Theoretical Modelsevaluation Of The Global Solar Irradiance In The Vhembe District Of Limpopo Province, South Africa, Using Different Theoretical Models, Tshimangadzo Sophie Mulaudzi, Nnditshedzeni Eric Maluta, Vaith Sankaran

Turkish Journal of Physics

An attempt has been made to employ three different theoretical models for the determination of global solar radiation for the climate conditions of the Vhembe district of Limpopo Province in South Africa. The models are: 1) the Angstrom linear-based model, 2) the Hargreaves and Samani (temperature-based) model, and 3) the Garcia model. These models require the following meteorological data inputs: temperature, sunshine hours, and global solar irradiance on the horizontal surface. The regression coefficients from our previous study were also employed in the calculations. A 4-year (2007--2010) global solar irradiance and temperature data set from the Agricultural Research Council and …

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A Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cellsa Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cells, Amal M. Al-Kahlout, Hatem S. El-Ghamri, Naji Al Dahoudi, Taher M. El-Agez, Sofyan A. Taya, Monzir S. Abdel-Latif Jan 2015

A Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cellsa Comparative Study: Synthetic Dyes As Photosensitizers For Dye-Sensitized \\Solar Cells, Amal M. Al-Kahlout, Hatem S. El-Ghamri, Naji Al Dahoudi, Taher M. El-Agez, Sofyan A. Taya, Monzir S. Abdel-Latif

Turkish Journal of Physics

In this paper, dye-sensitized solar cells (DSSCs) were fabricated using a zinc oxide (ZnO) semiconducting layer and different synthetic dyes. Eight different synthetic dyes were used to fabricate the DSSCs. Nanocrystalline ZnO powder was coated on transparent conducting fluorine-doped tin oxide glass using the doctor blade method to form a thin layer. The absorption spectra of the synthetic dyes were investigated. DSSCs were characterized with $J$-$V$ characteristic curves. The parameters reflecting the cell performance were calculated. The results revealed that eosin Y dye corresponds to the highest conversion efficiency. The dependence of the sintering temperature and the thicknesses of the …

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Nanocrystalline Nio Structure: Preferred Oriented Growthnanocrystalline Nio Structure: Preferred Oriented Growth, Ali Rahmati, Soheila Mardani Jan 2015

Nanocrystalline Nio Structure: Preferred Oriented Growthnanocrystalline Nio Structure: Preferred Oriented Growth, Ali Rahmati, Soheila Mardani

Turkish Journal of Physics

Nickel oxide (NiO) nanostructures were deposited on Si (100), potassium bromide (KBr), and glass slide substrates at room temperature by the evaporation technique. The prepared samples were annealed at temperatures of 400 $^{\circ}$C and 600 $^{\circ}$C in air atmosphere. The structure, morphology, crystalline phase, optical properties, and chemical bonding of nanocrystalline nickel oxide were investigated by scanning electron microscopy (SEM), X-ray diffraction (XRD), UV-visible absorption spectrum, and FT-IR spectroscopy. XRD results and SEM images showed that nickel oxide nanoparticles have preferred orientation with uniform size distribution. The as-deposited films showed preferred orientation (texture) growth. As the films were annealed, the …

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External Magnetic Field Effect On Bifacial Silicon Solar Cell''S Electric Power And Conversion Efficiencyexternal Magnetic Field Effect On Bifacial Silicon Solar Cell''S Electric Power And Conversion Efficiency, Issa Zerbo, Martial Zoungrana, Idrissa Sourabie, Adama Ouedraogo, Bernard Zouma, Dieudonne Joseph Bathiebo Jan 2015

External Magnetic Field Effect On Bifacial Silicon Solar Cell''S Electric Power And Conversion Efficiencyexternal Magnetic Field Effect On Bifacial Silicon Solar Cell''S Electric Power And Conversion Efficiency, Issa Zerbo, Martial Zoungrana, Idrissa Sourabie, Adama Ouedraogo, Bernard Zouma, Dieudonne Joseph Bathiebo

Turkish Journal of Physics

This article presents a modelling study of external magnetic field effect on a bifacial silicon solar cell's electric power and conversion efficiency. After the resolution of the magnetotransport equation and continuity equation of excess minority carriers, we calculate the photocurrent density and the photovoltage and then we deduce the solar cell's electric power before discussing the influence of the magnetic field on those electrical parameters. Using the electric power curves versus junction dynamic velocity we determine the maximum electric power, the operating point of the solar cell, and the conversion efficiency according to magnetic field intensity. The numerical data show …

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Dust-Ion Acoustic Shock Waves For Nonplanar Geometry With Nonthermal Electrons And Adiabatic Dusty Plasmadust-Ion Acoustic Shock Waves For Nonplanar Geometry With Nonthermal Electrons And Adiabatic Dusty Plasma, Louis Ete Akpabio Jan 2015

Dust-Ion Acoustic Shock Waves For Nonplanar Geometry With Nonthermal Electrons And Adiabatic Dusty Plasmadust-Ion Acoustic Shock Waves For Nonplanar Geometry With Nonthermal Electrons And Adiabatic Dusty Plasma, Louis Ete Akpabio

Turkish Journal of Physics

The nonplanar Burgers' equation for dust-ion-acoustic shock waves was derived for unmagnetized adiabatic dusty plasmas, comprising static negatively charged dust fluid, nonthermal distributed electrons, and Boltzmann distributed positron and adiabatic ion fluid, by employing the standard reductive perturbation method. The solution of the modified Burgers' equation for nonplanar geometry is numerically analyzed. The dependence of dust-ion-acoustic shock waves on some plasma parameters is explored. It is observed that inclusion of the nonthermal electron distribution modifies the shock wave profile significantly. Likewise, it is found that the nonplanar geometry effects have an important role on the establishment of shock waves. It …

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Empirical M X-Ray Production Cross Sections For Heavy Elements By Proton Impact Within Z-Dependence Analysisempirical M X-Ray Production Cross Sections For Heavy Elements By Proton Impact Within Z-Dependence Analysis, Bahri Deghfel, Farid Khalfallah, Abdelhalim Kahoul, Mohammed Nekkab Jan 2015

Empirical M X-Ray Production Cross Sections For Heavy Elements By Proton Impact Within Z-Dependence Analysisempirical M X-Ray Production Cross Sections For Heavy Elements By Proton Impact Within Z-Dependence Analysis, Bahri Deghfel, Farid Khalfallah, Abdelhalim Kahoul, Mohammed Nekkab

Turkish Journal of Physics

New empirical M-shell X-ray production cross sections have been deduced by introducing the dependence of the universal trend of the experimental data on the atomic number of the target, noted as "Z-dependence" for semiempirical cross sections in our previous work. For this effect, the updated experimental data (from 1980 to 2009) are used to calculate the empirical cross sections for heavy elements with 60 $\le $ Z $\le $ 90 by proton impact. Finally, a comparison is made between the deduced results and other earlier works.

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Sfp Effect On Majorana Type Solar Neutrinos In The Presence Of Nonstandard Neutrino Interactionssfp Effect On Majorana Type Solar Neutrinos In The Presence Of Nonstandard Neutrino Interactions, Deni̇z Yilmaz Jan 2015

Sfp Effect On Majorana Type Solar Neutrinos In The Presence Of Nonstandard Neutrino Interactionssfp Effect On Majorana Type Solar Neutrinos In The Presence Of Nonstandard Neutrino Interactions, Deni̇z Yilmaz

Turkish Journal of Physics

Assuming neutrinos are Majorana particles, neutrino oscillation is examined in the case of spin flavor precession (SFP) and nonstandard neutrino interaction (NSI). It is seen that the combined effect of them (SFP and NSI) is not ignorable for the neutrino oscillation.

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Two Common Terminological Mistakes In Scientific Paperstwo Common Terminological Mistakes In Scientific Papers, Şaki̇r Erkoç Jan 2015

Two Common Terminological Mistakes In Scientific Paperstwo Common Terminological Mistakes In Scientific Papers, Şaki̇r Erkoç

Turkish Journal of Physics

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An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy Jan 2015

An Acid-Bath Technique To Break Seed Dormancy In Common Sunflower, Helianthus L. Annuus (Asteraceae), Yuridia Patricia Gandy, Michael W. Persans, Kenneth R. Summy

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The phenomenon of seed dormancy is widespread in plants and serves to prevent all or most of a given population from germinating at the “wrong” time, e.g., during an unusually mild fall in an area subject to typically harsh winters. Seed dormancy is an effective survival strategy in many plant populations, but may greatly complicate efforts to establish large cohorts of seedlings (groups of similar age or developmental stage) needed for re-search and other purposes. In an effort to break seed dormancy in common sunflower, Helianthus annuus L. (Asteraceae), we conducted experiments designed to compare germination times and overall germination …

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Curcumin: A Folklore Remedy From Kitchen On The Way To Clinic As Cancer Drug, Debasish Bandyopadhyay Jan 2015

Curcumin: A Folklore Remedy From Kitchen On The Way To Clinic As Cancer Drug, Debasish Bandyopadhyay

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

Numerous compounds are widely distributed in nature and many of these possess medicinal/biological/pharmacological activity. Curcumin, a polyphenol derived from the rhizomes (underground stems) of Curcuma longa Linn (a member of the ginger family, commonly known as turmeric) is a culinary spice and therapeutic used in India for thousands of years to induce color and flavor in food as well as to treat a wide array of diseases. The origin of turmeric as spice and folklore medicine is so old that it is lost in legend. Curcumin has many beneficial pharmacological effects which includes, but are not limited with, antimicrobial, anti-inflammatory, …

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Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov Jan 2015

Palladium-Catalyzed C8-Selective C-H Arylation Of Quinoline N-Oxides: Insights Into The Electronic, Steric And Solvation Effects On The Site-Selectivity By Mechanistic And Dft Computational Studies, David E. Stephens, Johant Lakey-Beitia, Abdurrahman Atesin, Tülay A. Ateşin, Gabriel Chavez, Hadi D. Arman, Oleg V. Larionov

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

We report herein a palladium-catalyzed C-H arylation of quinoline N-oxides that proceeds with high selectivity in favor of the C8-isomer. This site-selectivity is unusual for palladium, since all of the hitherto described methods of palladium-catalyzed C-H functionalization of quinoline N-oxides are highly C2-selective. The reaction exhibits a broad synthetic scope with respect to quinoline N-oxides and iodoarenes and can be significantly accelerated to sub-hour reaction times under microwave irradiation. The C8-arylation method can be carried out on gram scale and has excellent functional group tolerance. Mechanistic and Density Functional Theory (DFT) computational studies provide evidence for the …

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Evaluating Success Factors In Implementing E-Maintenance In Maintenance, Repair, And Overhaul (Mro) Organizations, Peter Rocky Toves Jan 2015

Evaluating Success Factors In Implementing E-Maintenance In Maintenance, Repair, And Overhaul (Mro) Organizations, Peter Rocky Toves

Walden Dissertations and Doctoral Studies

Despite more than a decade-long process to transition aircraft maintenance practices from paper-to electronic-based systems, some organizations remain unable to complete this transition. Researchers have indicated that while organizations have invested resources in technology improvements, there remains a limited understanding of the factors that contribute to effectively managing technology-enabled change. The purpose of this case study was to identify and explore socio-technical (ST) factors that inhibit an effective transition from a paper-based system to an electronic-based system for aircraft maintenance. A conceptual model applying theories of change management, technology acceptance, systems thinking, and ST theory informed the research. Thirteen participants …

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Distinguishing Leadership Of Information Assurance Teams, Bamidele Adetokunbo Bankole Jan 2015

Distinguishing Leadership Of Information Assurance Teams, Bamidele Adetokunbo Bankole

Walden Dissertations and Doctoral Studies

Information assurance (IA) projects are essential components of the information technology industry and often fail due to budget overruns, missed deadlines, and lack of performance by the project teams. The purpose of this phenomenological study was to explore the strategies necessary to improve IA project team performance. Lewin's situational leadership theory was used as the conceptual framework for this study. Interviews were conducted with 20 IA professionals located in the Washington, DC Metropolitan area. The data were transcribed, coded, and clustered for the identification of common patterns based on the Moustakas' modified van Kaam analysis. The major themes that emerged …

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Transformational Leadership And Safe Driving Performance In The U.S. Electric Utility Industry, Mackington Joseph Jan 2015

Transformational Leadership And Safe Driving Performance In The U.S. Electric Utility Industry, Mackington Joseph

Walden Dissertations and Doctoral Studies

Transformational leadership (TL) has been found popular in many industries in the United States and abroad for the perceived transformational leaders' effectiveness in improving occupational safety. There is a lack of empirical evidence to confirm these claims for safe occupational driving. This phenomenological study attempted to fill this knowledge gap in the electric utility industry where employees must drive in all weather conditions to restore power to customers. The conceptual framework for the study was based on leadership and motivation theories of Burns and Maslow. The research questions explored the influence of (a) TL on safe driving performance improvement in …

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Nurses Knowledge, Skills, And Attitude Toward Electronic Health Records (Ehr), Sharon L. Adams Jan 2015

Nurses Knowledge, Skills, And Attitude Toward Electronic Health Records (Ehr), Sharon L. Adams

Walden Dissertations and Doctoral Studies

Information technology (IT) has been rapidly integrated into the healthcare industry, including nursing, and has the ability to reduce errors, cut cost, and enhance patient care. However, approximately 45% of the current nurse workforce lacks adequate training in computer skills, which may hinder the adoption of health-related IT in the workplace. Characteristics of Rogers's diffusion of innovation (relative advantage, compatibility, complexity, trialability, and observability) guided this project. This project was conducted to address the problem of IT adoption on a local level and was designed to assess whether simulation training on a generic electronic health record (EHR) system would improve …

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Engaging The Nonprofits In Louisville Housing Market For Low-Income Households, Joshua Omoniyi Odetunde Jan 2015

Engaging The Nonprofits In Louisville Housing Market For Low-Income Households, Joshua Omoniyi Odetunde

Walden Dissertations and Doctoral Studies

Nonprofit organizations often work in partnership with government agencies to empower low income people in the housing market through government subsidized mortgage loans. In spite of this assistance, homelessness and substandard housing is pervasive among low income households because this population primarily relies on the rental housing market, leaving a gap in practice and knowledge related to how nonprofits provide assistance to the overwhelming majority of low income consumers in need of housing. The purpose of this case study was to use social justice theory to explore how the nonprofit sector, as an economic force, provides assistance to and empowers …

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Animas-La Plata Project Stakeholder Narratives: A Case Study Using Kingdon's Three Streams Theory, Denise Renee Rue-Pastin Jan 2015

Animas-La Plata Project Stakeholder Narratives: A Case Study Using Kingdon's Three Streams Theory, Denise Renee Rue-Pastin

Walden Dissertations and Doctoral Studies

Population growth, coupled with changing weather patterns, is straining water supplies, especially in the American Southwest. A multitude of tools, including additional storage, will be needed to meet water demand and supply gaps. The Animas-La Plata Project, a reservoir in southwest Colorado, provides a case study of how groups worked for nearly 70 years to solve a water problem: insufficient irrigation for agriculture. This qualitative case study addressed a lack of first-person narratives from those most involved. Its purpose was to gather stakeholder narratives and analyze them using Kingdon's three streams theory to address the extent to which the problem, …

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Diffusion Of Technology In Small To Medium Medical Providers In Saudi Arabia, Ziad Hisham Arnaout Jan 2015

Diffusion Of Technology In Small To Medium Medical Providers In Saudi Arabia, Ziad Hisham Arnaout

Walden Dissertations and Doctoral Studies

The Saudi ministry of health reported that government health care spending doubled from 2008 to 2011. To address increased demand, the government encouraged small to medium enterprise (SME) growth. However, SME leaders could not leverage technology as a growth enabler because they lacked strategies to address operating inefficiencies associated with technology. Only 50% of hospitals fully implemented information technology. The purpose of this phenomenological study was to explore lived experiences of SME leaders on strategies needed to accelerate technology implementation. This exploration drew on a conceptual framework developed from Wainwright and Waring's framework addressing issues of technology adoption. Data were …

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Small Business Sustainability In The Salon Industry, Militea Johnson-Hilliard Jan 2015

Small Business Sustainability In The Salon Industry, Militea Johnson-Hilliard

Walden Dissertations and Doctoral Studies

Small businesses fail at high rates; 51% fail to succeed in business beyond the first 5 years. The purpose of this exploratory case study was to explore the strategies that salon business owners used to succeed in business. The sample comprised of 2 salon business owners in Savannah, Georgia who have been in business more than 5 years. The conceptual framework was based on the general systems theory. Data were collected from conducting semistructured interviews with each business owner, a review of company business plans, direct observation of participants during client interaction in the salon, as well as member-checking interview …

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Correlation Analysis Of Climatic Variables, Migration And Dengue Cases In Southeast Florida, Brunilda Lugo Jan 2015

Correlation Analysis Of Climatic Variables, Migration And Dengue Cases In Southeast Florida, Brunilda Lugo

Walden Dissertations and Doctoral Studies

Dengue fever is a debilitating, viral, mosquito-borne disease occurring in tropical and subtropical areas in the world. The majority of dengue cases in the United States were acquired in endemic areas by travelers or immigrants. However, in recent years, autochthonous (locally acquired) dengue cases have been diagnosed in Florida. The purpose of this study was to find an association between potential risk factors and the expansion of dengue fever in the United States. Guided by the eco-bio-social framework, which offers a broad assessment of risk factors for the illness, a retrospective design was used with archival data to correlate changes …

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Narrowing The Mathematical Achievement Gap Among African American And Latino Students, Muriel Eileen Smith Jan 2015

Narrowing The Mathematical Achievement Gap Among African American And Latino Students, Muriel Eileen Smith

Walden Dissertations and Doctoral Studies

This study focused on the continued mathematical achievement gap between African American and Latino students in an urban elementary school. An illustrative case study design was used to examine the teachers' perception of factors contributing to this gap in mathematical performance, and what instructional math strategies can narrow the achievement gap. Socioconstructivism and culturally relevant pedagogy were the learning theories used to form the conceptual framework in this study. Qualitative data were obtained from 6 individual interviews with 4th grade math educators, classroom observations, and teacher artifacts. Data analysis in this study included data triangulation and coding, as well as …

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Development Of Monolithic Column Materials For The Separation And Analysis Of Glycans, Keith Stine, Allan Alla Jan 2015

Development Of Monolithic Column Materials For The Separation And Analysis Of Glycans, Keith Stine, Allan Alla

Chemistry & Biochemistry Faculty Works

Monolithic column materials offer great advantages as chromatographic media in bioseparations and as solid-supports in biocatalysis. These single-piece porous materials have an interconnected ligament structure that limits the void volume inside the column, thus increasing the efficiency without sacrificing the permeability. The preparation of monolithic materials is easy, reproducible and has available a wide range of chemistries to utilize. Complex, heterogeneous and isobaric glycan structures require preparation methods that may include glycan release, separation and enrichment prior to a comprehensive and site-specific glycosylation analysis. Monolithic column materials aid that demand, as shown by the results reported by the research works …

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Small Business Use Of Internet Marketing: Findings From Case Studies, Maya Demishkevich Jan 2015

Small Business Use Of Internet Marketing: Findings From Case Studies, Maya Demishkevich

Walden Dissertations and Doctoral Studies

Internet marketing is critical for meeting changing consumer needs and staying competitive in the business environment. Small business owners need strategies on how to use Internet marketing to promote their products or services. The purpose of this multiple case study was to explore how 5 small business owners in Maryland developed and implemented an online marketing strategy. Participants were recruited for their roles as the chief decision maker of their business; additional prerequisites for their participation were that they used Internet marketing, represented different industries, and had fewer than 20 employees. Data came from semi-structured interviews with the small business …

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Effects Of Single-Gender And Coeducational Learning Environments On Middle School Mathematics Achievement, Tasha Graves Henderson Jan 2015

Effects Of Single-Gender And Coeducational Learning Environments On Middle School Mathematics Achievement, Tasha Graves Henderson

Walden Dissertations and Doctoral Studies

As a result of the increased number of schools failing to meet adequate yearly progress (AYP), school districts are searching for innovative ways to raise student achievement and meet the rigorous performance standards set by state governments. Using the theoretical framework provided by brain research and the theory of multiple intelligences, the purpose of this quantitative study was to compare 2 middle school classroom structures for differences in mathematics achievement among students. The study examined whether a significant difference existed in mathematics achievement scores on the state-mandated mathematics test for 2 groups (single gender classes versus coeducational classes) in 6 …

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