2,056 research outputs found
Measurements of Solid Spheres Bouncing Off Flat Plates
Recent years have seen a substantial increase of interest in the flows of granular materials whose rheology is dominated by the physical contact between particles and between particles and the containing walls. Considerable advances in the theoretical understanding of rapid granular material flows have been made by the application of the statistical methods of molecular gas dynamics (e.g., Jenkins and Savage (1983), Lun et al. (1984)) and by the use of computers simulations of these flows (e.g., Campbell and Brennen (1985), Walton (1984)). Experimental studies aimed at measurements of the fundamental rheology properties are much less numerous and are understandably limited by the great difficulties involved in trying to measure velocity profiles, solid fraction profiles, and fluctuating velocities within a flowing granular material. Nevertheless, it has become clear that one of the most severe problems encountered when trying to compare experimental data with the theoretical models is the uncertainty in the material properties governing particle/particle or particle/wall collisions. Many of the theoretical models and computer simulations assume a constant coefficient of restitution (and, in some cases, a coefficient of friction).
The purpose of the present project was to provide some documentation for particle/wall collisions by means of a set of relatively simple experiments in which solid spheres of various diameters and materials were bounced off plates of various thickness and material. The objective was to provide the kind of information on individual particle/wall collisions needed for the theoretical rheological models and computer simulations of granular material flows: in particular, to help resolve some of the issues associated with the boundary condition at a solid wall. For discussion of the complex issues associated with dynamic elastic or inelastic impact, reference is made to Goldsmith (1960) and the recent text by Johnson (1985)
An exploration of the roles of Pleribo, Adraste, and Prince Florilame in Tony Kushner\u27s adaptation of The Illusion: a production thesis in acting
This thesis is constructed from the author’s interpretation of the roles of Pleribo, Adraste, and Prince Florilame in Tony Kushner’s adaptation of Pierre Corneille’s The Illusion, which was presented by LSU Theatre in 2004. This thesis is a written record of the actor’s work on these characters throughout the rehearsal and performance process in the form of a score. It also includes an introduction, character analysis, and a conclusion
THE EFFECTS OF SYSTEMATIC UNLOADING ON MUSCLE ACTIVATION AND FATIGUE DURING RESISTANCE EXERCISE
This study examined acute, local muscle fatigue and recovery, temporally, during velocity-based resistance exercise. A dynamic single-leg extension resistance exercise model with systematic unloading based on changes in repetition velocity was used to measure changes in quadriceps muscle activation patterns. EMG indices of acute, local muscle fatigue and recovery were closely associated with changes in movement velocity for each unloading condition. Systematic Unloading (SU) is an effective resistance training protocol in order to minimize acute, local muscle fatigue and facilitate muscle fatigue recovery within a se
Transmissivity of carbon monoxide in the 2.3 microns band region
Line strengths and self and nitrogen broadened half-widths have been determined from high resolution spectroscopic measurements of selected lines in the 2.3 micrometer band region of CO. The CO 0-2 total band strength is estimated to be 2.086 + or - 0.146 cm/1 (ATM-cm)/1 STP which is higher than most previously reported values. The line half-widths are also generally higher than those in the literature
The effect of storage on the quality properties of Oilseed Rape straw pellets.
With the growing demand for biomass for alternative energy supplies, it would be prudent to investigate alternative sources of energy. The layer study of which this is part will investigate the effect of pre and post pelletization storage on the quality and combustion properties of oilseed rape straw, which, unlike wood pellets, have had little or no detailed research upon the variation of the physical, chemical, biological and combustion properties over the period of storage. This paper focuses on the effect of storage time on oilseed rape straw pellets in terms of pellet quality. The quality of oilseed rape straw pellets was assessed in terms of durability, hardness and particle density. Results show the quality of the pellets is affected by storage time. The durability and particle density of pellets increased between 2 weeks and 3 months storage, before decreasing up to 12 months storage. The hardness of pellets continuously increases during the 12 months storage. It is clear storage time influenced the properties of OSR straw pellets, but it is suspected that there are other factors (e.g. binder, raw material, natural variations) that could be affecting these quality parameters
Role of the Chemokine System in Liver Fibrosis: A Narrative Review
BACKGROUND AND OBJECTIVE: Liver fibrosis is a disease with characteristics of an aberrant wound healing response. Fibrosis is commonly the end-stage for chronic liver diseases like alcohol-associated liver disease (ALD), metabolic-associated liver disease, viral hepatitis, and hepatic autoimmune disease. Innate immunity contributes to the progression of many diseases through multiple mechanisms including production of pro-inflammatory mediators, leukocyte infiltration and tissue injury. Chemokines and their receptors orchestrate accumulation and activation of immune cells in tissues and are associated with multiple liver diseases; however, much less is known about their potential roles in liver fibrosis. This is a narrative review of current knowledge of the relationship of chemokine biology to liver fibrosis with insights into potential future therapeutic opportunities that can be explored in the future.
METHODS: A comprehensive literature review was performed searching PubMed for relevant English studies and texts regarding chemokine biology, chronic liver disease and liver fibrosis published between 1993 and 2021. The review was written and constructed to detail the intriguing chemokine biology, the relation of chemokines to tissue injury and resolution, and identify areas of discovery for fibrosis treatment.
KEY CONTENT AND FINDINGS: Chemokines are implicated in many chronic liver diseases, regardless of etiology. Most of these diseases will progress to fibrosis without appropriate treatment. The contributions of chemokines to liver disease and fibrosis are diverse and include canonical roles of modulating hepatic inflammation as well as directly contributing to fibrosis via activation of hepatic stellate cells (HSCs). Limited clinical evidence suggests that targeting chemokines in certain liver diseases might provide a therapeutic benefit to patients with hepatic fibrosis.
CONCLUSIONS: The chemokine system of ligands and receptors is a complex network of inflammatory signals in nearly all diseases. The specific sources of chemokines and cellular targets lend unique pathophysiological consequences to chronic liver diseases and established fibrosis. Although most chemokines are pro-inflammatory and contribute to tissue injury, others likely aid in the resolution of established fibrosis. To date, very few targeted therapies exist for the chemokine system and liver disease and/or fibrosis, and further study could identify viable treatment options to improve outcomes in patients with end-stage liver disease
High-resolution modeling of the spatial heterogeneity of soil moisture: Applications in network design
The spatial heterogeneity of soil moisture remains a persistent challenge in the design of in situ measurement networks, spatial downscaling of coarse estimates (e.g., satellite retrievals), and hydrologic modeling. To address this challenge, we analyze high-resolution (∼9 m) simulated soil moisture fields over the Little River Experimental Watershed (LREW) in Georgia, USA, to assess the role and interaction of the spatial heterogeneity controls of soil moisture. We calibrate and validate the TOPLATS distributed hydrologic model with high to moderate resolution land and meteorological data sets to provide daily soil moisture fields between 2004 and 2008. The results suggest that topography and soils are the main drivers of spatial heterogeneity over the LREW. We use this analysis to introduce a novel network design method that uses land data sets as proxies of the main drivers of local heterogeneity (topography, land cover, and soil properties) to define unique and representative hydrologic similar units (subsurface, surface, and vegetation) for probe placement. The calibration of the hydrologic model and network design method illustrates how the use of hydrologic similar units in hydrologic modeling could minimize computation and guide efforts toward improved macroscale land surface modeling
Health Literacy in Occupational Therapy Research: A Scoping Review
Background: Low health literacy is a significant problem in the United States. Patient education is a key component of occupational therapy intervention. Occupational therapists have the skills to develop patient education materials (PEMs) all patients can understand. Few studies on health literacy exist in occupational therapy research. The purpose of this scoping review was to summarize the breadth of literature on health literacy in occupational therapy research and to identify knowledge gaps.
Method: A scoping review methodological framework (Arksey and O’Malley, 2005; Levac et al., 2010) was used to search five databases. A descriptive numerical summary and qualitative thematic analysis were used to summarize the results.
Results: Eighteen articles met the inclusion criteria. Quantitative results describe variation in research design, outcome measures, intervention focus, and setting. Qualitative themes include exploring health literacy knowledge, practices and perceptions of occupational therapists, and assessment of consumer needs and understanding related to health literacy. Gaps in the literature include the impact of low health literacy on patient outcomes, guidelines for appraising and modifying PEMs, and the effectiveness of modified PEMs.
Conclusion: There is a need to establish evidence-based guidelines and a standard of care for patients with low health literacy
Human prostatic Acid phosphatase: structure, function and regulation.
Human prostatic acid phosphatase (PAcP) is a 100 kDa glycoprotein composed of two subunits. Recent advances demonstrate that cellular PAcP (cPAcP) functions as a protein tyrosine phosphatase by dephosphorylating ErbB-2/Neu/HER-2 at the phosphotyrosine residues in prostate cancer (PCa) cells, which results in reduced tumorigenicity. Further, the interaction of cPAcP and ErbB-2 regulates androgen sensitivity of PCa cells. Knockdown of cPAcP expression allows androgen-sensitive PCa cells to develop the castration-resistant phenotype, where cells proliferate under an androgen-reduced condition. Thus, cPAcP has a significant influence on PCa cell growth. Interestingly, promoter analysis suggests that PAcP expression can be regulated by NF-κB, via a novel binding sequence in an androgen-independent manner. Further understanding of PAcP function and regulation of expression will have a significant impact on understanding PCa progression and therapy
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