Pion Transparency in 500 MeV C(pi,pi') Reactions?

The question whether there is a pion transparency in 500 MeV $C(\pi, \pi^{'})$ scatterings is studied using a semiclassical, hadronic transport model. The double differential cross sections of this reaction measured at LAMPF can be largely accounted for, if one uses energy-dependent, anisotropic angular distributions which are fitted to pion-nucleon scattering data for the decay of $\Delta(1232)$ and $N^*(1440)$ resonances. The remaining discrepancy between the data and the calculation sets a limit on effects of more exotic processes.Comment: Latex file, 11 pages, 3 figures availabe upon request. Phys. Lett. B in pres

An effective mesh strategy for CFD modelling of polymer electrolyte membrane fuel cells

Computational fluid dynamics (CFD) is a major tool in PEM fuel cell research. Typical three-dimensional PEM fuel cell models involve more than 106 mesh elements. This makes the computation very intense and necessitates a methodology to mesh the computational domain that can keep the number of elements to a minimum while maintaining good accuracy. In this study, the effect of computational mesh in each direction on the accuracy of the solution is investigated in a systematic way. It is found that the mesh in different directions has a different degree of influence on the solution suggesting that the mesh in one direction can be coarser than the other. The proposed mesh strategy is capable of greatly reducing the number of mesh elements, hence computation time, while preserving the characteristics of important flow-field variables. Moreover, it is applicable to a wide range of cell sizes and flow-field configurations and should be used as a guideline for mesh generation

Detection of Auditory Signals in Quiet and Noisy Backgrounds while Performing a Visuo-spatial Task

The ability to detect important auditory signals while performing visual tasks may be further compounded by background chatter. Thus, it is important to know how task performance may interact with background chatter to hinder signal detection. Aim: To examine any interactive effects of speech spectrum noise and task performance on the ability to detect signals. Settings and Design: The setting was a sound-treated booth. A repeated measures design was used. Materials and Methods: Auditory thresholds of 20 normal adults were determined at 0.5, 1, 2 and 4 kHz in the following conditions presented in a random order: (1) quiet with attention; (2) quiet with a visuo-spatial task or puzzle (distraction); (3) noise with attention and (4) noise with task. Statistical Analysis: Multivariate analyses of variance (MANOVA) with three repeated factors (quiet versus noise, visuo-spatial task versus no task, signal frequency). Results: MANOVA revealed significant main effects for noise and signal frequency and significant noise–frequency and task–frequency interactions. Distraction caused by performing the task worsened the thresholds for tones presented at the beginning of the experiment and had no effect on tones presented in the middle. At the end of the experiment, thresholds (4 kHz) were better while performing the task than those obtained without performing the task. These effects were similar across the quiet and noise conditions. Conclusion: Detection of auditory signals is difficult at the beginning of a distracting visuo-spatial task but over time, task learning and auditory training effects can nullify the effect of distraction and may improve detection of high frequency sounds

Audibility, Cost-Acceptibility and Cosmetic Appearance of IQBuds BOOST in Adults Over the Age of 50

Background: Hearing loss affects 48 million Americans and up to 86% of all adults with hearing loss may not wear hearing aids. Untreated hearing loss is associated with social withdrawal, depression, stress, loss of income, and dementia. Even so, people still tend not to buy or wear hearing aids for a variety of reasons. One recently suggested solution to this problem is low-cost, over the counter (OTC) hearing aids, nicknamed “hearables” This study evaluated the audibility, cost-acceptability and cosmetic appearance of one OTC, IQBuds BOOST. Methods: Fourteen men and 12 women over 50 years with a hearing loss participated in the study. Word recognition testing was conducted by presenting words embedded with a phrase at 40 dBHL through the loudspeakers in four conditions. The participants completed a Visual Analogue Survey, which included listening and non-listening items, once regarding their aided experience and once regarding their everyday listening experience. Analyses: Speech perception was scored using both the phoneme scoring and word scoring methods. Mixed ANOVAs were performed on the % correct phoneme scores and word scores. The t-test was performed on the average scores of the first 12 items of the Visual Analogue scale. Descriptive statistics were used to report data on the questions related to cost and acceptability of the hearable device. Results: For both aided and unaided conditions the word and phoneme recognition scores in noise were significantly poorer than those in quiet. The hearable did not improve the word recognition in quiet or noisy backgrounds. Similarly, there were no significant differences in average listening VAS scores with and without the hearable. On a scale of 1 to 100, participants gave higher than 60 scores for questions regarding the comfort, fit and insertion of the hearable. However, the average scores related to willingness to use, cost, and cosmetic appearance were less than 50. Conclusions: This study suggests that older participants with mild to moderate hearing loss may not benefit from the hearable used in the current study and the appearance of the device may have to be improved

Pion-nucleus elastic scattering on 12C, 40Ca, 90Zr, and 208Pb at 400 and 500 MeV

Pion-nucleus elastic scattering at energies above the Delta(1232) resonance is studied using both pi+ and pi- beams on 12C, 40Ca, 90Zr, and 208Pb. The present data provide an opportunity to study the interaction of pions with nuclei at energies where second-order corrections to impulse approximation calculations should be small. The results are compared with other data sets at similar energies, and with four different first-order impulse approximation calculations. Significant disagreement exists between the calculations and the data from this experiment

B Cells Regulate Neutrophilia during Mycobacterium tuberculosis Infection and BCG Vaccination by Modulating the Interleukin-17 Response

We have previously demonstrated that B cells can shape the immune response to Mycobacterium tuberculosis, including the level of neutrophil infiltration and granulomatous inflammation at the site of infection. The present study examined the mechanisms by which B cells regulate the host neutrophilic response upon exposure to mycobacteria and how neutrophilia may influence vaccine efficacy. To address these questions, a murine aerosol infection tuberculosis (TB) model and an intradermal (ID) ear BCG immunization mouse model, involving both the μMT strain and B cell-depleted C57BL/6 mice, were used. IL (interleukin)-17 neutralization and neutrophil depletion experiments using these systems provide evidence that B cells can regulate neutrophilia by modulating the IL-17 response during M. tuberculosis infection and BCG immunization. Exuberant neutrophilia at the site of immunization in B cell-deficient mice adversely affects dendritic cell (DC) migration to the draining lymph nodes and attenuates the development of the vaccine-induced Th1 response. The results suggest that B cells are required for the development of optimal protective anti-TB immunity upon BCG vaccination by regulating the IL-17/neutrophilic response. Administration of sera derived from M. tuberculosis-infected C57BL/6 wild-type mice reverses the lung neutrophilia phenotype in tuberculous μMT mice. Together, these observations provide insight into the mechanisms by which B cells and humoral immunity modulate vaccine-induced Th1 response and regulate neutrophila during M. tuberculosis infection and BCG immunization. © 2013 Kozakiewicz et al

Image Merging in Transform Domain

This paper presents the three different image merging techniques and there comparative analysis. Idea of our project is to merge two images in transform domain using MATLAB. The various transform domains which are used for merging are Fast Fourier Transform (FFT), Discrete Cosine Transform (DCT) and Discrete Wavelet Transform (DWT). Our main aim would be merging two images using the above three domains. These two images which are to be merged are in actual blurred images. They are blurred in such a way that in first image some part on one side is blurred while in second image the other side is blurred. Image merging is required in several fields such as remote sensing using satellite imagery, biomedical, surveillance, military applications etc. &nbsp

Young Adults’ Knowledge and Attitudes Regarding “Music” and “Loud Music” Across Countries: Applications of Social Representations Theory

Exposure to loud music, especially by young people, has significantly increased in recent years as a result of (a) advancements in technology in terms of personal music players and smart mobile phones, and (b) streaming of music through these devices. The World Health Organization (WHO) estimates that some 1.1 billion teenagers and young adults are at risk of developing hearing loss due to exposure to recreational noise such as music. It is suggested that knowledge and attitude of young adults toward music has bearing upon their music listening habits and thereby influences who is at risk of developing music induced hearing loss. Hence, researchers from various fields have tried to understand the knowledge and attitude of young adults regarding loud music. However, there is some criticism of attitude studies as there is little relation between expressed attitude and behavior. Some recent studies have explored the social representations of music and loud music using the Social Representations Theory (SRT). It has been suggested that social representation is more fundamental than attitude (or in other words social representation informs attitude), hence, it has a better relation to behavior. The current paper: (1) provides an overview of studies on knowledge and attitude of young adults toward loud music, (2) discusses the limitations of attitude theories and introduces SRT, and (3) provides a summary of social representation studies on “music” and “loud music” in young adults from different countries

Modeling the effect of inhomogeneous compression of GDL on local transport phenomena in a PEM fuel cell

The effects of inhomogeneous compression of gas diffusion layers (GDLs) on local transport phenomena within a polymer electrolyte membrane (PEM) fuel cell were studied theoretically. The inhomogeneous compression induced by the rib/channel structure of the flow field plate causes partial deformation of the GDLs and significantly affects material parameters. The results suggest that inhomogeneous compression does not significantly affect the polarization behavior or gas-phase mass transport. However, the effect of inhomogeneous compression on the current density distribution is evident. Local current density under the channel was substantially smaller than under the rib when inhomogeneous compression was taken into account, while the current density distribution was fairly uniform for the model which excluded the effect of inhomogeneous compression. This is caused by the changes in the selective current path, which is determined by the combinations of conductivities of components and contact resistance between them. Despite the highly uneven current distribution and variation in material parameters as a function of GDL thickness, the temperature profile was relatively even over the active area for both modeled cases, contrary to predictions in previous studies. However, an abnormally high current density significantly accelerates deterioration of the membrane and is critical in terms of cell durability. Therefore, fuel cells should be carefully designed to minimize the harmful effects of inhomogeneous compression

Development of methodology for detection of defect locations in pavement profile

Pavement smoothness has become a standard measure of pavement quality. Transportation agencies strive to build and maintain smoother pavements. Smooth roads provide comfort while riding, minimize vehicular wear and tear and increase pavement life. A user perceives smoothness of a pavement based on the ride quality, which is severely affected by presence of defects on pavement surface. Defects identified after construction are corrected as per smoothness specifications prescribed by respective transportation agencies. The effectiveness of any method used to determine defect locations depends on the decrease in roughness obtained on correction of defects. Following the above line of thought a method that detects defects by comparing original profile to a smoothened profile will be more effective in identifying defect locations that cause roughness in pavements. This research report proposes a methodology to detect defect locations on pavement surface using profile data collected on pavements. The approach presents a method of obtaining a smoothened profile from the original profile to help identify defect locations based on deviations of the original profile from the smoothened one. Defect areas will have a higher deviation from the smoothened profile as compared to smooth areas. The verification of the defects identified by this approach is carried out by determining the decrease in roughness after removal of the identified defects from profile. A roughness statistic is used to do the same. The approach is illustrated using profile data collected on in-service pavement sections