Saturated fluorescence measurements of the hydroxyl radical in laminar high-pressure flames

The efficacy of laser saturated fluorescence (LSF) for OH concentration measurements in high pressure flames was studied theoretically and experimentally. Using a numerical model describing the interaction of hydroxyl with nonuniform laser excitation, the effect of pressure on the validity of the balanced cross-rate model was studied along with the sensitivity of the depopulation of the laser-coupled levels to the ratio of rate coefficients describing: (1) electronic quenching to (sup 2) Sigma (+) (v double prime greater than 0), and (2) vibrational relaxation from v double prime greater than 0 to v double prime = 0. At sufficiently high pressures and near-saturated conditions, the total population of the laser-coupled levels reaches an asymptotic value, which is insensitive to the degree of saturation. When the ratio of electronic quenching to vibrational relaxation is small and the rate of coefficients for rotational transfer in the ground and excited electronic states are nearly the same, the balanced cross-rate model remains a good approximation for all pressures. When the above ratio is large, depopulation of the laser-coupled levels becomes significant at high pressures, and thus the balanced cross-rate model no longer holds. Under these conditions, however, knowledge of the depletion of the laser-coupled levels can be used to correct the model. A combustion facility for operation up to 20 atm was developed to allow LSF measurements of OH in high pressure flames. Using this facility, partial saturation in laminar high pressure (less than or equal to 12.3 atm) C2H6/O2/N2 flames was achieved. To evaluate the limits of the balanced cross-rate model, absorption and calibrated LSF measurements at 3.1 and 6.1 atm were compared. The fluorescence voltages were calibrated with absorption measurements in an atmospheric flame and corrected for their finite sensitivity to quenching with: (1) estimated quenching rate coefficients, and (2) an in situ measurement from a technique employing two fluorescence detection geometries

De-aliasing Undersampled Volume Images for Visualization

We present and illustrate a new technique, Image Correlation Supersampling (ICS), for resampling volume data that are undersampled in one dimension. The resulting data satisfies the sampling theorem, and, therefore, many visualization algorithms that assume the theorem is satisfied can be applied to the data. Without the supersampling the visualization algorithms create artifacts due to aliasing. The assumptions made in developing the algorithm are often satisfied by data that is undersampled temporally. Through this supersampling we can completely characterize phenomena with measurements at a coarser temporal sampling rate than would otherwise be necessary. This can save acquisition time and storage space, permit the study of faster phenomena, and allow their study without introducing aliasing artifacts. The resampling technique relies on a priori knowledge of the measured phenomenon, and applies, in particular, to scalar concentration measurements of fluid flow. Because of the characteristics of fluid flow, an image deformation that takes each slice image to the next can be used to calculate intermediate slice images at arbitrarily fine spacing. We determine the deformation with an automatic, multi-resolution algorithm

International Outsourcing in the Information Technology Industry: Trends and Implications

This paper reviews trends in the use of international outsourcing in the Information Technology (IT) industry and explores implications for the U.S. workforce. Workforce employment projections and the trend for globalization in the IT industry are analyzed. An analogy is developed between current trends in IT workforce and the globalization of the auto industry during the latter part of the 20th century. The conclusion is that recent dips in U.S. IT employment may represent more than a transitory reflection of current economic conditions. International IT providers may be capturing a permanent share of U.S. IT expenditures and thus reducing the long term need for U.S. IT employment. IT industry and educational institutions need to plan accordingly for these new global workforce realities

Conflict in the Indian Kashmir Valley I: exposure to violence.

ABSTRACT: BACKGROUND: India and Pakistan have disputed ownership of the Kashmir Valley region for many years, resulting in several conflicts since the end of partition in 1947. Very little is known about the prevalence of violence and insecurity in this population. METHODS: We undertook a two-stage cluster household survey in two districts (30 villages) of the Indian part of Kashmir to assess experiences with violence and mental health status among the conflict-affected Kashmiri population. The article presents our findings for confrontations with violence. Data were collected for recent events (last 3 months) and those occurring since the start of the conflict. Informed consent was obtained for all interviews. RESULTS: 510 interviews were completed. Respondents reported frequent direct confrontations with violence since the start of conflict, including exposure to crossfire (85.7%), round up raids (82.7%), the witnessing of torture (66.9%), rape (13.3%), and self-experience of forced labour (33.7%), arrests/kidnapping (16.9%), torture (12.9%), and sexual violence (11.6%). Males reported more confrontations with violence than females, and had an increased likelihood of having directly experienced physical/mental maltreatment (OR 3.9, CI: 2.7-5.7), violation of their modesty (OR 3.6, CI: 1.9-6.8) and injury (OR 3.5, CI: 1.4-8.7). Males also had high odds of self-being arrested/kidnapped (OR 8.0, CI: 4.1-15.5). CONCLUSION: The civilian population in Kashmir is exposed to high levels of violence, as demonstrated by the high frequency of deliberate events as detention, hostage, and torture. The reported violence may result in substantial health, including mental health problems. Males reported significantly more confrontations with almost all violent events; this can be explained by higher participation in outdoor activities

A Comparison of Job Satisfaction among Women in Computing and a More Traditional Female Occupation

Despite the economic slowdown of the early 2000s, Information Technology (IT) workers are likely to remain in high demand in the U.S. for the next decade. One of the problems faced in meeting this demand is the gender discrepancy in choosing IT employment; men are far more likely to engage in IT careers than women. Although there are many potential reasons for this discrepancy, satisfaction in one’s job is likely to be an influence in career choice. This study compares the satisfaction of women in a professional computing career to those in a more traditionally female career—elementary school teachers

Gauging the Relationship Between Contextual Growth and Structural Neglect

Population and land use out-migrations from urban to peripheral areas can result in non-functional, unmaintained historic structures which deteriorate to the point where removal is cheaper than removal – or demolition by neglect. The increasing rate of neglected historic structures is a growing concern. There is a need for research investigating connections between urban growth management and its effect on neglect. This paper applies Newman\u27s (2013) conceptual model of measuring neglect to Geographic Information Systems, comparing rates of neglect in historic Doylestown, Quakertown, and Bristol boroughs in Pennsylvania, USA utilizing different amounts of peripheral agricultural preservation. Comparisons are made examining descriptive statistics on existing conditions, a Polychoric correlation evaluating relationships between drivers of neglect, and a cross-comparative GIS spatial analysis. Results indicate as amounts of peripheral preserved farmlands increase, neglect can be lowered

African Americans' views on research and the Tuskegee Syphilis Study

The participation of African Americans in clinical and public health research is essential. However, for a multitude of reasons, participation is low in many research studies. This article reviews the literature that substantiates barriers to participation and the legacy of past abuses of human subjects through research. The article then reports the results of seven focus groups with 60 African Americans in Los Angeles, Chicago, Washington, DC, and Atlanta during the winter of 1997. In order to improve recruitment and retention in research, the focus group study examined knowledge of and attitudes toward medical research, knowledge of the Tuskegee Syphilis Study, and reactions to the Home Box Office production, Miss Evers' Boys, a fictionalized version of the Tuskegee Study, that premiered in February, 1997. The study found that accurate knowledge about research was limited; lack of understanding and trust of informed consent procedures was problematic; and distrust of researchers posed a substantial barrier to recruitment. Additionally, the study found that, in general, participants believed that research was important, but they clearly distinguished between types of research they would be willing to consider participating in and their motivations for doing so

An Untriggered Search for Optical Bursts

We present an untriggered search for optical bursts with the ROTSE-I telephoto array. Observations were taken which monitor an effective 256 square degree field continuously over 125 hours to m_{ROTSE}=15.7. The uniquely large field, moderate limiting magnitude and fast cadence of $\sim$10 minutes permits transient searches in a new region of sensitivity. Our search reveals no candidate events. To quantify this result, we simulate potential optical bursts with peak magnitude, m_{p}, at t=10 s, which fade as f=(\frac{t}{t_{0}}) ^{\alpha_{t}}, where \alpha_t < 0. Simple estimates based on observational evidence indicate that a search of this sensitivity begins to probe the possible region occupied by GRB orphan afterglows. Our observing protocol and image sensitivity result in a broad region of high detection efficiency for light curves to the bright and slowly varying side of a boundary running from [\alpha_{t},m_{p}]=[-2.0,6.0] to [-0.3,13.2]. Within this region, the integrated rate of brief optical bursts is less than 1.1\times 10^{-8} {\rm s}^{-1} {\rm deg}^{-2}. At $\sim$22 times the observed GRB rate from BATSE, this suggests a limit on \frac{\theta_{opt}}{\theta_{\gamma}}\lesssim 5 where \theta_{opt} and \theta_{\gamma} are the optical and gamma-ray collimation angles, respectively. Several effects might explain the absence of optical bursts, and a search of the kind described here but more sensitive by about 4 magnitudes should offer a more definitive probe.Comment: 8 pages, 6 figures, 1 tabl

Isometric hip and knee torque measurements as an outcome measure in robot assisted gait training

Strength changes in lower limb muscles following robot assisted gait training (RAGT) in subjects with incomplete spinal cord injury (ISCI) has not been quantified using objective outcome measures. To record changes in the force generating capacity of lower limb muscles (recorded as peak voluntary isometric torque at the knee and hip), before, during and after RAGT in both acute and subacute/chronic ISCI subjects using a repeated measures study design. Eighteen subjects with ISCI participated in this study (Age range: 26–63 years mean age = 49.3 ± 11 years). Each subject participated in the study for a total period of eight weeks, including 6 weeks of RAGT using the Lokomat system (Hocoma AG, Switzerland). Peak torques were recorded in hip flexors, extensors, knee flexors and extensors using torque sensors that are incorporated within the Lokomat. All the tested lower limb muscle groups showed statistically significant (p < 0.001) increases in peak torques in the acute subjects. Comparison between the change in peak torque generated by a muscle and its motor score over time showed a non-linear relationship. The peak torque recorded during isometric contractions provided an objective outcome measure to record changes in muscle strength following RAGT