Slip effects in vertical structure behind cavitating propeller wake

The cavitating propeller wake is investigated in detail using PIV and shadow graph techniques to figure out the trace ability of bubble type of tracers, naturally generated by the decrease of the static pressure in a cavitation tunnel. Experiments are conducted in the conditions of the cavitating propeller wake containing strong vortices. The flow behaviors of bubble tracers are compared with those of normal solid particles. The bubbles grown from the nuclei melted in the cavitation tunnel could not influence on the additional buoyancy, producing good trace ability in the uniform flow. The comparison between bubbles and solids shows some discrepancies in the area around the tip vortex core of cavitating propeller wake. The slip velocity, indicating the difference of moving velocities between bubble and solid, induces rather high difference in the vorticity values of it. The results of comparison in terms of vorticity values showed good agreement in the region of mild ReS (Reynolds number based on the slip velocity), however, disagreement at high ReS over 1000. The large slip velocity and high ReS provided a velocity difference, especially in the high velocity gradient region. The slipstream region gives a range of 15 <ReS < 75; however, ReS is about 1000 at a high velocity gradient region of a tip vortex. The fitted vorticity reduction rate would give a reference for the prediction in a real flow when bubble tracers are utilized in PIV measurements of a vortical flow. The vorticity reduction rates are obtained according to the bubble size which is considered to affect the slip effect in the high velocity gradient region.http://deepblue.lib.umich.edu/bitstream/2027.42/84208/1/CAV2009-final16.pd

Generic Skills Development in the Gulf Cooperation Council Countries and Graduate Outcomes: A Systematic Review of the Literature

Generic skills are essential because today’s jobs and the future of work require flexibility, initiative, and the ability to undertake many different tasks. While higher education graduates in the Gulf Cooperation Council (GCC) countries recognize the contribution of these skills in their academics and workplace performance, generic skills development is not a consistent part of their education, which has led to socioeconomic challenges. If higher education placed a great emphasis on developing generic skills, students would expect to have pragmatic benefits, such as academic success, boosting workplace performance, positive interpersonal relationships, and better health and overall well-being. To the best of our knowledge, no systematic review has been conducted to examine generic skills development outcomes in the GCC. Hence, this systematic review aims to identify, evaluate, and summarize findings from peer-reviewed and policy-related studies that have documented generic skills development outcomes in the GCC countries, including identifying broad definitions used and areas for future research. The findings demonstrated conclusive evidence regarding the effectiveness of generic skills development at the higher education level in enhancing graduate outcomes in employability promotion skills, enhancing stakeholder engagement in curriculum and instruction, academic or workplace performance, influences on health, and effects on social dimensions

Korean- and English-Speaking Children Use Cross-Situational Information to Learn Novel Predicate Terms

This paper examines children’s attention to cross-situational information during word learning. Korean-speaking children in Korea and English speaking children in the US were taught four nonce words that referred to novel actions. For each word, children saw four related events: half were shown events that were very similar (Close comparisons), half were shown events that were not as similar (Far comparisons). The prediction was that children would compare events to each other and thus be influenced by the events shown. In addition, children in these language groups could be influenced differently as their verb systems differ. Although some differences were found across language, children in both languages were influenced by the type of events shown, suggesting that they are using a comparison process. Thus, this study provides evidence for comparison, a new mechanism to describe how children learn new action words, and demonstrates that this process could apply across languages

Corporate social responsibility performance and outsourcing: The case of the Bangladesh tragedy

Multinational firms frequently outsource the manufacturing of their products to factories in less- developed countries to take advantage of much lower labor costs. A tragic disaster occurred in Bangladesh in April 2013 when a clothing factory building collapsed, killing more than a thousand workers. Subsequently, textile companies in the U.S. and in Europe who outsource their manufacturing in Bangladesh had to decide whether to commit to better working conditions by signing one of two worker safety agreements (WSAs) born in the after-math of the tragedy. Although many firms signed one of these agreements, many more did not. This study explores the relationship between an actual corporate social responsibility (CSR) commitment and firm performance, using a sample of companies who signed one of the WSAs after the Bangladesh disaster and those who did not. The results suggest that the decision to sign is positively associated with social visibility, prior CSR performance, and impact in stock price after the tragedy. Regarding subsequent performance, investors favorably responded to the news of firms’ signing on to the WSA agreement

The Association Between Audit Fees and Accounting Restatement Resulting from Accounting Fraud and Clerical Errors

Restatements of financial reporting arise from many sources including changes in accounting rules, changes in reporting entity, accounting errors, and fraud (or “irregularities”). Theory predicts that audit effort (measured by audit fees) and financial report restatements should be negatively associated because more audit effort means that auditors should be more likely to find errors or other issues that could lead to later restatement (Shibano 1990; Matsumura and Tucker, 1992; Lobo and Zhao, 2013). However, other studies have found either a positive association or no association between audit fees and subsequent restatements (Kinney et al., 2004; Stanley and DeZoort, 2007; Cao et al., 2012; Hribar, Kravet, and Wilson, 2014). There is an ongoing inconsistency between the theory and empirical findings in this area (Lobo and Zhao, 2013). In this study, we investigate the relationship between audit fees and two specific types of restatements: those caused by either fraud or errors. Whereas errors are unintentional misapplications of GAAP, or mistakes in data analysis, fraud is intentional and deliberate misreporting. Prior research provides evidence that investors differentiate between errors and irregularities (e.g., Palmrose, et al., 2004) and market reaction is greater to irregularities than to errors

Effect of Ispaghula and Oxyphenonium Bromide on the Symptoms of Irritable Bowel Syndrome - A Comparative Study

Background: Irritable bowel syndrome is a chronic continuous or remittent gastrointestinal illness characterized byfrequent unexplained symptoms that include abdominal pain, bloating, and bowel disturbance, in our country, no studyhas been conducted using the Ispaghula husk and oxyphenonium bromide for the treatment of IBS patients. Objectives:To compare the efficacy of treatment with Ispaghula husk and Oxyphenonium bromide. Methods: Total sixty patientsdiagnosed clinically as irritable bowel syndrome irrespective of subtype who fulfilled the Rome II criteria were includedequally into two groups-Group-I (Ispaghula group) &amp; Group-II (Oxyphenonium group). In Group-I patients were given30gm of Ispaghula husk at night daily and in Group-II patients were given 5mg of oxyphenonium bromide. After sixweeks the clinical parameters of both the groups recorded in the case record forms were taken for analysis. Results: Themean age of the patients in the Group- I were 33.4&plusmn;11.9 yrs and that of the patients in the Group-II were 31.0&plusmn;17.5 yrs.Male and female ratio in group I was 14:1 and in group II was 23:7. Most of the patients were recorded in the age groupof 26-30 in both groups. Symptom free patients were graded in 16.7% patients in Group-I and in 20% patients in Group-II. No improvement was occurred in 16.7% patients in Group-I and in 10% patients in Group-II. Conclusions: Ispaghulahusk shows the better efficacy to improve the symptoms of IBS like abdominal pain or discomfort and sense of well beingthan Oxyphenonium bromide. Oxephenonium bromide shows the better efficacy to decrease the stool frequency frombase line than Ispaghula husk.DOI: 10.3329/bsmmuj.v3i1.5506BSMMU J 2010; 3(1): 3-

Strong-field effects in the Rabi oscillations of the superconducting phase qubit

Rabi oscillations have been observed in many superconducting devices, and represent prototypical logic operations for quantum bits (qubits) in a quantum computer. We use a three-level multiphoton analysis to understand the behavior of the superconducting phase qubit (current-biased Josephson junction) at high microwave drive power. Analytical and numerical results for the ac Stark shift, single-photon Rabi frequency, and two-photon Rabi frequency are compared to measurements made on a dc SQUID phase qubit with Nb/AlOx/Nb tunnel junctions. Good agreement is found between theory and experiment.Comment: 4 pages, 4 figures, accepted for publication in IEEE Trans. Appl. Supercon

Subspace Detectors: Efficient Implementation

The optimum detector for a known signal in white Gaussian background noise is the matched filter, also known as a correlation detector [Van Trees, 1968]. Correlation detectors offer exquisite sensitivity (high probability of detection at a fixed false alarm rate), but require perfect knowledge of the signal. The sensitivity of correlation detectors is increased by the availability of multichannel data, something common in seismic applications due to the prevalence of three-component stations and arrays. When the signal is imperfectly known, an extension of the correlation detector, the subspace detector, may be able to capture much of the performance of a matched filter [Harris, 2006]. In order to apply a subspace detector, the signal to be detected must be known to lie in a signal subspace of dimension d {ge} 1, which is defined by a set of d linearly-independent basis waveforms. The basis is constructed to span the range of signals anticipated to be emitted by a source of interest. Correlation detectors operate by computing a running correlation coefficient between a template waveform (the signal to be detected) and the data from a window sliding continuously along a data stream. The template waveform and the continuous data stream may be multichannel, as would be true for a three-component seismic station or an array. In such cases, the appropriate correlation operation computes the individual correlations channel-for-channel and sums the result (Figure 1). Both the waveform matching that occurs when a target signal is present and the cross-channel stacking provide processing gain. For a three-component station processing gain occurs from matching the time-history of the signals and their polarization structure. The projection operation that is at the heart of the subspace detector can be expensive to compute if implemented in a straightforward manner, i.e. with direct-form convolutions. The purpose of this report is to indicate how the projection can be computed efficiently for continuous multichannel seismic data. The speed of the calculation is significant as it may become desirable to deploy subspace detectors numbering in the thousands. One application contemplated for these detectors is as screens against signals from repeating sources such as mines or aftershocks of large earthquakes. With many tens of stations and potentially hundreds of sources to screen, efficient implementations are desirable. Speed, of course, can be achieved by procuring faster computers or special-purpose hardware. The approach we examine here is the development of two efficient algorithms that can make the calculations run faster on any machine. In the first section, we describe the subspace detector as we use it for the detection of repeating seismic events, defining terms and the parameterization used in succeeding sections. This section also reviews how the correlation computations central to the matched filter and subspace detectors can be implemented as a collection of convolution operations. Convolution algorithms using fast Fourier transforms, such as the overlap-add and overlap-save methods, have long been known as efficient implementations of discrete-time finite-impulse-response filters [e.g. Oppenheim and Schafer, 1975]. These may be extended in a straightforward manner to implement multichannel correlation detectors. In the second section, we describe how multichannel data can be multiplexed to compute the required convolutions with a single pair of FFT operations instead of a pair for each channel. This approach increases speed approximately twofold. Seismic data, almost invariably, are oversampled. This characteristic provides an opportunity for increased efficiency by decimating the data prior to performing the correlation calculations. In the third section, we describe a bandpass transformation of the data that allows a more aggressive decimation of the data without significant loss of fidelity in the correlation calculation. The transformation computes a complex-analytic representation for the template waveforms and the multichannel data, followed by a demodulation for both to base-band (i.e. a single band around zero frequency). This approach provides a factor of two to four increase in speed depending on the details of data sampling rate and the desired pass band of the correlation calculation. The approaches described in the last two sections can be used simultaneously to compound efficiencies

Comparison of coherence times in three dc SQUID phase qubits

We report measurements of spectroscopic linewidth and Rabi oscillations in three thin-film dc SQUID phase qubits. One device had a single-turn Al loop, the second had a 6-turn Nb loop, and the third was a first order gradiometer formed from 6-turn wound and counter-wound Nb coils to provide isolation from spatially uniform flux noise. In the 6 - 7.2 GHz range, the spectroscopic coherence times for the gradiometer varied from 4 ns to 8 ns, about the same as for the other devices (4 to 10 ns). The time constant for decay of Rabi oscillations was significantly longer in the single-turn Al device (20 to 30 ns) than either of the Nb devices (10 to 15 ns). These results imply that spatially uniform flux noise is not the main source of decoherence or inhomogenous broadening in these devices.Comment: 4 pages, 5 figures, accepted for publication in IEEE Trans. Appl. Supercon