Variable mixture ratio performance through nitrogen augmentation

High/variable mixture ratio O2/H2 candidate engine cycles are examined for earth-to-orbit vehicle application. Engine performance and power balance information are presented for the candidate cycles relative to chamber pressure, bulk density, and mixture ratio. Included in the cycle screening are concepts where a third fluid (liquid nitrogen) is used to achieve a variable mixture ratio over the trajectory from liftoff to earth orbit. The third fluid cycles offer a very low risk, fully reusable, low operation cost alternative to high/variable mixture ratio bipropellant cycles. Variable mixture ratio engines with extendible nozzle are slightly lower performing than a single mixture ratio engine (MR = 7:1) with extendible nozzle. Dual expander engines (MR = 7:1) have slightly better performance than the single mixture ratio engine. Dual fuel dual expander engines offer a 16 percent improvement over the single mixture ratio engine

“I\u27ll do whatever as long as you keep telling me that I’m important”: A case study illustrating the link between adolescent dating violence and sex trafficking victimization

Background: Approximately 10% of U.S. high school-attending youth are physically abused by a dating partner each year. Many sequelae of dating violence have been documented, but the dating violence literature is lacking information about commercial sexual exploitation as a possible outcome of an abusive dating relationship. Conversely, scholarship on sex trafficking victimization has documented that some girls are enticed into sex work by exploitative partners who initially pretend to be dating partners, but the research lacks specificity about why and how the girls become vulnerable to these destructive relationships. This case series chronicles the experiences of four women who were commercially sexually exploited in the U.S. as minors, identifies common themes cross their narratives, and organizes these themes into a proposed framework for understanding a possible pathway from safety to unsafe dating to sex trafficking victimization. Methods: We conducted in-depth qualitative interviews with four adult women who had firsthand experience as victims of domestic minor sex trafficking. Participants were recruited through an organization that serves sex trafficking survivors. A constructivist grounded approach was used for data analysis. Participants’ narratives are presented, as well as illustrative quotes that typify each of the primary themes identified. Results: There were six primary themes that emerged from the cases’ narratives. Factors that made girls vulnerable to entering into abusive dating relationships and subsequently to experiences as sex trafficked minors included: (1) feeling physically unattractive and unimportant; (2) lacking examples of healthy relationships; (3) experiencing sexual abuse that caused subsequent dissociation and emotional debilitation; (4) being flattered by romantic gestures early in an abusive dating relationship and becoming emotionally attached; (5) gaining confidence from dating someone with higher social status; and (6) experiencing short-term satisfaction from out-earning other sex workers. Secondary themes that merit further investigation included having conflicts with guardians, engaging in criminal behavior at the request of their dating partner, and developing substance dependence that made it difficult to exit sex work. Discussion: Findings support the conclusions that one pathway into commercial sexual exploitation for minors is via dating partners, and that some minors are motivated to engage in sex work out of devotion to their dating partners rather than fear of violent retribution. A proposed framework for understanding how youth become vulnerable to sexual exploitation by a dating partner includes pre-dating, early phase dating, and late phase dating factors. Some pre-dating factors, for example, include feeling insecure, being bullied by peers, and having conflict with a guardian. Early phase dating factors include being impressed by the high social status of a new love interest and romantic gestures. Late phase dating factors include engaging in criminal activity to please the dating partner, and being physically, sexually, financially and emotionally abused. Additional empirical research that replicates and expands the proposed framework is encouraged, with the long-term objective of improving both dating violence and sexual exploitation prevention initiative

DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2lasers

A parametric analysis of DIAL sensitivity with heterodyne detection is presented and comparisons with direct detection are discussed. Examples are given for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system. Results indicate that maximum sensitivity at minimum laser energy per measurement requires multiple pulse operation with the energy per pulse selected so that the measured photon rate is approximately equal to the detector IF bandwidth. Measurement sensitivities can be maximized and interference effects minimized by fine adjustment of measurement frequencies using the tunability of high pressure lasers. The use of rare isotope lasers minimizes loss due to CO2 atmospheric absorption

DIAL with heterodyne detection including speckle noise: Aircraft/shuttle measurements of O3, H2O, and NH3 with pulsed tunable CO2 lasers

Atmospheric trace constituent measurements with higher vertical resolution than attainable with passive radiometers are discussed. Infrared differential absorption lidar (DIAL), which depends on Mie scattering from aerosols, has special advantages for tropospheric and lower stratospheric applications and has great potential importance for measurements from shuttle and aircraft. Differential absorption lidar data reduction involves comparing large amplitude signals which have small differences. The accuracy of the trace constituent concentration inferred from DIAL measurements depends strongly on the errors in determining the amplitude of the signals. Thus, the commonly used SNR expression (signal divided by noise in the absence of signal) is not adequate to describe DIAL measurement accuracy and must be replaced by an expression which includes the random coherent (speckle) noise within the signal. A comprehensive DIAL computer algorithm is modified to include heterodyne detection and speckle noise. Examples for monitoring vertical distributions of O3, H2O, and NH3 using a ground-, aircraft-, or shuttle-based pulsed tunable CO2 laser DIAL system are given

Argonne Laboratory Computing Resource Center - FY2004 Report.

In the spring of 2002, Argonne National Laboratory founded the Laboratory Computing Resource Center, and in April 2003 LCRC began full operations with Argonne's first teraflops computing cluster. The LCRC's driving mission is to enable and promote computational science and engineering across the Laboratory, primarily by operating computing facilities and supporting application use and development. This report describes the scientific activities, computing facilities, and usage in the first eighteen months of LCRC operation. In this short time LCRC has had broad impact on programs across the Laboratory. The LCRC computing facility, Jazz, is available to the entire Laboratory community. In addition, the LCRC staff provides training in high-performance computing and guidance on application usage, code porting, and algorithm development. All Argonne personnel and collaborators are encouraged to take advantage of this computing resource and to provide input into the vision and plans for computing and computational analysis at Argonne. Steering for LCRC comes from the Computational Science Advisory Committee, composed of computing experts from many Laboratory divisions. The CSAC Allocations Committee makes decisions on individual project allocations for Jazz

Thermodynamic Scaling of the Viscosity of Van Der Waals, H-Bonded, and Ionic Liquids

Viscosities and their temperature, T, and volume, V, dependences are reported for 7 molecular liquids and polymers. In combination with literature viscosity data for 5 other liquids, we show that the superpositioning of relaxation times for various glass-forming materials when expressed as a function of TV^g, where the exponent g is a material constant, can be extended to the viscosity. The latter is usually measured to higher temperatures than the corresponding relaxation times, demonstrating the validity of the thermodynamic scaling throughout the supercooled and higher T regimes. The value of g for a given liquid principally reflects the magnitude of the intermolecular forces (e.g., steepness of the repulsive potential); thus, we find decreasing g in going from van der Waals fluids to ionic liquids. For strongly H-bonded materials, such as low molecular weight polypropylene glycol and water, the superpositioning fails, due to the non-trivial change of chemical structure (degree of H-bonding) with thermodynamic conditions.Comment: 16 pages 7 figure

Myocardial Ischemia with Penetrating Thoracic Trauma

Penetrating trauma is a rare cause of myocardial infarction. Our report describes a 47-year-old female who presented with a gunshot wound from a shotgun and had an ST-elevation myocardial infarction. The patient received emergent coronary angiography, which demonstrated no evidence of coronary atherosclerotic disease but did show occlusion of a marginal vessel secondary to a pellet. The patient was managed medically for the myocardial infarction without cardiac sequelae. Patients with penetrating trauma to the chest should be evaluated for myocardial ischemia. Electrocardiography, echocardiography and cardiac angiography play vital roles in evaluating these patients and helping to guide management