725 research outputs found
Do coverage expansion and patient-centeredness care delivery improve patient health outcomes and care quality?
Although correlated, improvement of patient health outcomes and quality of care is a result of health care delivery, performance, and healthcare policies that intend to impact health outcomes (Porter, 2010; AHRQ, 2015). This dissertation focuses on a special model of care delivery (Patient-Centered Medical Homes (PCMH)) and two programs (Addiction and Recovery Treatment Services (ARTS) and Medicaid expansion) to examine the correlation and impact of these programs on cardiovascular-related preventive care, healthcare expenditures, and health behavior hospitalizations as patient outcomes
PREDICTING THE DYNAMIC BEHAVIOR OF COAL MINE TAILINGS USING STATE-OF-PRACTICE GEOTECHNICAL FIELD METHODS
This study is focused on developing a method to predict the dynamic behavior of mine tailings dams under earthquake loading. Tailings dams are a by-product of coal mining and processing activities. Mine tailings impoundments are prone to instability and failure under seismic loading as a result of the mechanical behavior of the tailings. Due to the existence of potential seismic sources in close proximity to the coal mining regions in the United States, it is necessary to assess the post-earthquake stability of these tailings dams.
To develop the aforementioned methodology, 34 cyclic triaxial tests along with vane shear tests were performed on undisturbed mine tailings specimens from two impoundments in Kentucky. Therefore, the liquefaction resistance and the residual shear strength of the specimens were measured. The laboratory cyclic strength curves for the coal mine specimens were produced, and the relationship between plasticity, density, cyclic stress ratio, and number of cycles to liquefaction were identified.
The samples from the Big Branch impoundment were generally loose samples, while the Abner Fork specimens were dense samples, older and slightly cemented. The data suggest that the number of loading cycles required to initiate liquefaction in mine tailings, NL, decreases with increasing CSR and with decreasing density. This trend is similar to what is typically observed in soil. For a number of selected specimens, using the results of a series of small-strain cyclic triaxial tests, the shear modulus reduction curves and damping ratio plots were created.
The data obtained from laboratory experiments were correlated to the previously recorded geotechnical field data from the two impoundments. The field parameters including the SPT blow counts (N1)60, corrected CPT cone tip resistance (qt), and shear wave velocity (vs), were correlated to the laboratory measured cyclic resistance ratio (CRR). The results indicate that in general, the higher the (N1)60 and the tip resistance (qt), the higher the CSR was.
Ultimately, practitioners will be able to use these correlations along with common state-of-practice geotechnical field methods to predict cyclic resistance in fine tailings to assess the liquefaction potential and post-earthquake stability of the impoundment structures
Prediction of Tonal Acoustic Radiation Due to Feedback-Loop Resonant Interactions in Transitional Airfoils
The objective to this work is to employ the surface integral methods to study the far-field noise propagation from the flow acoustic resonant interactions of the transitional airfoil. The Potential-Theoretic Method (PTM) as an advancement to traditional Kirchhoff methods is presented. The PTM eliminated the need to calculate the normal derivatives of pressure and an arbitrary Kirchhoff surface can be employed. The numerical procedure to implement the PTM is fairly simple. The formulation and physical assumptions of the approach is reviewed, and the numerical procedure is implemented. Furthermore, the two dimensional formulation of the Ffowcs Williams - Hawkings (FW-H) equation in frequency, domain is reviewed and then the method is implemented to be used for extending the numerical simulations to far-field evaluations. In order to verify the implemented methods, monopole source verification problems has been studied and the accuracy of the methods is validated. Then, PTM and FW-H methods are used in the transitional airfoil application. The noise generation process of the problem in the near-field is highly nonlinear. This, high accuracy 2D simulations based on an Implicit Large Eddy Simulation (ILES) code are conducted for a NACA-0012 airfoil for the Reynolds of 140,000 and zero angle of attack as the baseline case, to obtain the time-dependent flow variables in the near-field. Then the near-field data is passed to the developed PTM and FW-H codes to evaluate the far-field noise acoustics. The predicted acoustic sound pressure level and the directivities are compared with direct CFD simulation in the mid region where toe CFD results are still reliable. Comparing the results, it is deduced that the FW-H is more robust in regards to the choice of control surface. Some remarks about signal processing and properties of the methods are suggested. The acoustic predictions are also evaluated for a far-field microphone probe, to compare them with experimental results. The effects of variations of angle of attack on the tonal noise regime has been studied
Aeroacoustics of Supersonic Jet Interacting with Solid Surfaces and its Suppression
The noise generated by supersonic jet is of primary interest in the high-speed flight. In several flight conditions jet exhaust of the propulsion system interacts with solid surfaces. For example, jet impingement on ground for a rocket lift-off, or interactions influenced by the integration of the engine with the airframe. Such complex applications require consideration of the role of acoustic-surface interactions on the noise generation of the jet and its radiation. Numerical analysis of supersonic jet noise involved in these scenarios is investigated by employing Hybrid Large Eddy Simulation – Unsteady Reynolds Averaged Simulation approach to model turbulence.
First, the supersonic impinging jet noise reduction using aqueous injectors is investigated. The technique employed to suppress impingement noise, involves injecting liquid water from the ground surface. The Volume of Fluid model is adopted to simulate the two phase flow. The flow field and acoustic results agree well with the existing experimental data. The possible mechanisms of noise reduction by water injection are investigated.
Second, supersonic jet noise reduction by employing the shielding effect of a flat plate parallel to the jet is investigated. The numerical simulations model the shielding effect of the flat plate on the acoustics of supersonic jet, and results agree with the corresponding experimental data. The physical mechanisms involved in the flow-surface interactions are investigated. With understanding these mechanisms, a slightly wavy plate is proposed including theoretical background to determine the parameters needed for the way wall to provide acoustic reduction efficiently. Results show that the proposed wavy shield can effectively reduce both the level and extent of the jet noise source as compared to that of a flat shield
Analytical Study of Coupling Effects for Vibrations of Cable-Harnessed Beam Structures
This paper presents a distributed parameter model to study the effects of the harnessing cables on the dynamics of a host structure motivated by space structures applications. The structure is modeled using both Euler-Bernoulli and Timoshenko beam theories. The presented model studies the effects of coupling between various coordinates of vibrations due to the addition of the cable. The effects of the cable’s offset position, pre-tension and radius are studied on the natural frequencies of the system. Strain and kinetic energy expressions using linear displacement field assumptions and Green-Lagrange strain tensor are developed. The governing coupled partial differential equations for the cable-harnessed beam that includes the effects of the cable pre-tension are found using Hamilton’s principle. The natural frequencies from the coupled Euler Bernoulli, Timoshenko and decoupled analytical models are found and compared to the results of the Finite Element Analysis.Natural Sciences and Engineering Research Council, Discovery Gran
P53 and Ki67 biomarkers as prognostic factors of non small cell lung carcinoma
Biomolecular behavior of tumor cells has become attractive to investigators. p53 as an oncosuppresor gene has been core of various studies and Ki67 is a nuclear protein involved in proliferation process. Stopping of onco-suppressor function theoretically allows proliferative system to get out of any control. In this case-control study we evaluated 50 patients with non small cell lung cancer, considering the association between P53 oncoprotein and Ki67 with rate of tumoral cells differentiation. We found the concurrent move of P53 and Ki67 according to the rate of differentiation and a significant risk (odds ratio) for being poorly differentiated in samples having higher rates of these two factors. We suppose that mutant P53 protein not only may be used as an objective finding for tumor grading, but probably as a practical point of approach for determining prognosis and planning therapy for this patients
Coupled Dynamics of Cable-Harnessed Structures: Experimental Validation
The experimental study and model validations for the coupled dynamics of a cable-harnessed beam structure are presented. The system under consideration consists of multiple pretensioned cables attached along the length of the host beam structure positioned at an offset distance from the beam centerline. Analytical model presented by the coupled partial differential equations (PDEs) for various coordinates of vibrations is found, and the displacement frequency response functions (FRFs) obtained for both Euler–Bernoulli and Timoshenko-based models are compared to those from the experiments for validation. The results are shown to be in very good agreement with the experiments.Natural Sciences and Engineering Research Council of Canada, Grant RGPIN-2016-0485
Prediction of the load carrying capacity of elevated steel fibre reinforced concrete slabs
A novel methodology is developed for predicting the load carrying capacity of elevated
steel fibre reinforced concrete (E-SFRC) slab systems. In the proposed approach the
depth of slab’s cross section is discretized into several layers, and the number of steel
fibres per each layer is determined by considering the distribution of fibres along the
depth of cross section. This information, together with the one obtained from the threepoint
notched beam bending tests performed on four series of SFRC made of different
concrete strength class and content of fibres, have provided the stress-crack width laws
for defining the post-cracking behaviour of each layer. These constitutive laws are
implemented in a numerical model developed based on the moment-rotation approach
for determining the positive and negative resisting bending moment of the slab’s unit
width cross section. By using the yield line theory, the load carrying capacity of ESFRC
slab is predicted for the most current load conditions. Predictive performance of
the proposed methodology is assessed comparing to the results recorded in experiment
and the ones obtained by the numerical simulation. Finally the developed model is
utilised in a parametric study to evaluate the influence of parameters that affect the
load-carrying capacity of E-SFRC slabs.This work is supported by FEDER funds through the Operational Program for Competitiveness Factors - COMPETE and National Funds through FCT - Portuguese
Foundation for Science and Technology under the project “SlabSys – HFRC – Flat slabs for multi-storey buildings using hybrid reinforced self-compacting concrete: an innovative structural system” PTDC/ECM/120394/2010. The first author also acknowledges the financial supports provided by Seismic Geotechnical and High Performance Concrete Research Centre of Semnan Branch, Islamic Azad University.info:eu-repo/semantics/publishedVersio
Overview of the antibacterial properties of essential oils and extracts of medicinal plants in Iran
Background and aims: With increased resistance resulting from overusing of chemical-synthetic antibiotics, finding alternative medicines that have antibacterial properties and they have the least side effects on human health appears to be necessary. Many studies have been taken into consideration medicinal plants with antimicrobial properties. The aim of this study was to have an overview of the antibacterial properties of medicinal plants.
Methods: In this study, by searching key words as: herbs (Medicinal Plants), anti-bacterial properties of medicinal plants in Iran , antimicrobial properties of medicinal plants in Iran, in scientific articles published in databases as: Iranmedx, Magiran, Google scholar, Ebsco, Pubmed, Science direct, and SID, the required data were obtained.
Results: Many herbs, including Zataria multifora, Urtica dioical, Crocus sativus L., Artemisia Absinthium, Menta piperita, Eucalyptus globules L., Borago officinalis L., Scrophularia desrti, Cuminum cyminum L., Rosmarinus officinalis L., Allium hirtifolium, Castaneifolia- sativa, Allium sativum, Pycnocycla spinose, Juglans Regia, Salvia officinalis L. have strong antibacterial properties against a variety of pathogenic bacteria.
Conclusion: In addition to the various medicinal plants with antimicrobial susceptibility and pathogenic bacteria resistance, antimicrobial properties of these studied medicinal plants could be used as a natural preservative in a variety of foods from these herbs. Thyme and garlic have antibacterial effects on an extensive range of positive and negative gram bacteria through them
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