A linearized Euler analysis of unsteady flows in turbomachinery

A method for calculating unsteady flows in cascades is presented. The model, which is based on the linearized unsteady Euler equations, accounts for blade loading shock motion, wake motion, and blade geometry. The mean flow through the cascade is determined by solving the full nonlinear Euler equations. Assuming the unsteadiness in the flow is small, then the Euler equations are linearized about the mean flow to obtain a set of linear variable coefficient equations which describe the small amplitude, harmonic motion of the flow. These equations are discretized on a computational grid via a finite volume operator and solved directly subject to an appropriate set of linearized boundary conditions. The steady flow, which is calculated prior to the unsteady flow, is found via a Newton iteration procedure. An important feature of the analysis is the use of shock fitting to model steady and unsteady shocks. Use of the Euler equations with the unsteady Rankine-Hugoniot shock jump conditions correctly models the generation of steady and unsteady entropy and vorticity at shocks. In particular, the low frequency shock displacement is correctly predicted. Results of this method are presented for a variety of test cases. Predicted unsteady transonic flows in channels are compared to full nonlinear Euler solutions obtained using time-accurate, time-marching methods. The agreement between the two methods is excellent for small to moderate levels of flow unsteadiness. The method is also used to predict unsteady flows in cascades due to blade motion (flutter problem) and incoming disturbances (gust response problem)

Effects of Drought Stress on Corn Production

Corn grain and forage yields are reduced throughout most of South Dakota. This publication discusses 1) drought stress effects on corn yield potential, 2) how to estimate potential grain yields prior to harvest, and 3) alternate uses for drought stressed corn

Effects of Drought Stress on Soybean Production

In late July, the hot, dry weather accelerated the maturity of the soybean crop about 8 days ahead of normal. About 85% of the crop had bloomed and 25% had started to form pods. This publication discusses 1) how drought stress affects potential soybean yields, 2) how to estimate potential soybean yields prior to harvest, and 3) alternate uses of drought stressed soybeans

Broadcast Profanity and the Right to Be Let Alone: Can the FCC Regulate Non-Indecent Fleeting Expletives under a Privacy Model

This manuscript examines the issue of broadcast profanity regulation in light of the Supreme Court\u27s March 2008 decision to grant certiorari in an appeal from the U.S. Court of Appeals for the Second Circuit. The Second Circuit in 2007 held that the FCC was arbitrary and capricious in its decision to begin prohibiting single profanities, or fleeting expletives, on broadcast television. However, the common law of nuisance and the law of privacy may provide justification for the FCC to regulate broadcast profanity under 18 U.S.C. § 1464. Although some argue that regulating broadcast profanity would induce a chilling effect on broadcast speech or would be futile in light of proliferation of profanity across society, relevant Supreme Court precedents seem to allow prohibition of profanity when it attempts to enter the home. A review is undertaken of the status of profanity in the law by examining the history of nuisance actions for profanity as well as contemporary zones of activity, including schools, the workplace and courtrooms, in which the law allows prohibitions on profanity

Buoyant surface jets discharged into a strong crossflow

Analytical and experimental investigations were carried out for three-dimensional buoyant surface jets with strong ambient flow but without boundary attachment. A numerical model in curvilinear coordinates was developed from an integral jet analysis modified for buoyancy effects and included asymmetry of the jet. Detailed temperature distributions were measured in the laboratory with densimetric Froude numbers (F̥) of 5, 10 and 15 and 0 velocity ratios (R) from 2 to 13. Experimental results showed that ambient crossflows can cause significant distortion of the jet, even for R = 13. Near the exit, the lower portion of the jet is swept toward the lee side of the jet. The resulting L-shaped cross section and the associated density instability may enhance spreading on the lee side and may contribute to the subsequent formation of bimodal temperature distributions. The jet bending increases as R decreases and as F̥ increases. Dilution increases with increasing F̥ and decreasing R. The model was calibrated against the entire set of measured temperatures for each run and is capable of predicting temperature 0 distributions to an accuracy of 0.63C˚. The agreement could probably be improved by using similarity profiles better suited to the actual jet cross sectional shape which was not known at the beginning of the research.U.S. Department of the InteriorU.S. Geological SurveyOpe

Winter Observations of Mammals and Birds, St. Matthew Island

Remore and uninhabited St. Matthew Island, lying 60 30 N, 172 30 W, on the continental shelf of the Bering Sea, is infrequently visited in summer and very rarely seen in the winter. The only signs of past human habitation are the wind-torn remains of a World War II naval observation station and the rectangular depressions of a couple of Eskimo house pits, of undetermined age, on the southwest side of the island. The last known visit to the island was during the summer of 1966. Our opportunity came on 6 and 7 February 1970, as a result of an oceanographic cruise aboard the U.S. Coast Guard icebreaker Northwind to study winter conditions in the ice-covered Bering Sea. At that time the island was covered with crusted, wind-glazed snow and locked in sea ice, with open water only along the south shore where large leads had opened up in the lee of the island. The weather was cold and very windy, temperatures ranging from 10°F to -20°F with a wind velocity averaging 30 to 40 knots, from the north. The afternoon of the 6th was clear, permitting a helicopter survey of the entire island. Most of the daylight hours of the 7th were occupied by ground investigations of the island under worsening weather conditions (overcast sky and 40-knot wind). The mammal population of the island is sparse .... We saw only arctic fox and reindeer, with no evidence of small mammals though they are known to exist there. ... Species observed on or in the vicinity of St. Matthew: Arctic Fox (Alopex lagopus), Reindeer (Rangifer tarandus), Walrus (Odobenus rosmarus), Ringed Seal (Phoca hispida,) Snowy Owl (Nyctea scandiaca), Thick-billed Murre (Uria lomvia), Harlequin (Histrionicus histrionicus), Common Eider (Somateria mollissima), King Eider (Somateria spectabilis), Old squaw (Clangula hyemalis), Pelagic Cormorant (Phalacrocorax pelagicus), Slaty-backed Gull (Larus schistisagus), Glaucous-winged Gull (Larus glaucescens), Glaucous Gull (Larus hyperboreus), Ivory Gull (Pagophila eburnea). We found a single herd of 32 reindeer at the southeast corner of the island. The animals were large and appeared to be in good condition, with impressive antlers. They are the remnant of a reindeer population introduced in 1944 that experienced a spectacular increase to 6,000 animals before crashing to 42 in the winter of 1963-64. Klein visited St. Matthew in the summer of 1966 to study the remaining reindeer and collected 10 animals, including the last male. He left 32 animals, all thought to be female, and all of which survived the intervening three and a half years up to the time of our arrival on the island. The observed marine mammal populations in the vicinity of St. Matthew proved to be disappointing. ... Ringed and bearded seals and walrus were observed some distance to the east of St. Matthew, in the edge of the sea ice in Bristol Bay; walrus were seen in large numbers north of the island, in the vicinity of St. Lawrence, so it seems likely that there should be marine mammals present in the area. ... The bird fauna of St. Matthew and vicinity was more diverse than that of the mammal. Twelve species were seen around the island, all of which, with the exception of a snowy owl, were marine and were observed in the leads and polynyas of the sea ice. Most common were murres, harlequins, and oldsquaws. ... As the ship proceeded westward from St. Matthew toward the Siberian coast, murres, black guillemots, and 4 species of gulls were seen. Several slaty-backed and glaucous-winged gulls were seen, and 3 glaucous and 2 ivory gulls observed near 60°N, 175°W. [Interestingly] ... of all the gulls seen, the slaty-back was by far the most common. This species is not considered common in Alaska

Study of stratified overflows and underflows

The study presents a general analysis of two-layered stratified flows taking into account effects of sidewall friction and variation of density with horizontal distance. The analysis is applied to the study of arrested thermal wedges and arrested cold water intrusions. Laboratory data were collected and analyzed and it was determined that bed roughness has a significant effect on the interfacial friction factor for arrested thermal wedges but not for arrested cold water intrusions. Friction factors were found to vary significantly along the wedges indicating that use of average values is perhaps undesirable. Local values of friction factor were found to increase with values of a local interfacial Reynolds number.U.S. Department of the InteriorU.S. Geological SurveyOpe

Adjunctive intravitreal dexamethasone in the treatment of acute endophthalmitis following cataract surgery

Edward F Hall1, Garrett R Scott1, David C Musch1,2, David N Zacks11Department of Ophthalmology and Visual Sciences, Medical School; 2Department of Epidemiology, School of Public Health; University of Michigan, Ann Arbor, MI, USAPurpose: Controversy exists regarding the use of intravitreal dexamethasone (IVD) as an anti-inflammatory adjunct to intravitreal antibiotics in patients with acute endophthalmitis following cataract surgery. The purpose of this project was to evaluate our experience regarding the effect of adjunctive IVD use on visual outcomes in such patients.Design: Retrospective, comparative case series.Methods: Study population: Patients treated for acute endophthalmitis following cataract surgery from 1995–2004. Intervention: In addition to standard intravitreal antibiotic treatment, some patients also received a single adjunctive injection of IVD. Primary outcome measures: Median visual acuity at last follow-up and percentage of patients achieving a ≥3-line improvement in visual acuity. Secondary outcome measures: Inflammatory index scoring, including amount of cell and flare, height of hypopyon, and presence of fibrin as a function of time after treatment.Results: Twenty-six eyes were treated with and 38 eyes without adjunctive IVD. Median presenting visual acuity was Hand Motion in both groups. Median visual acuity at last followup measured 20/40 in the IVD group and 20/50 in the No-IVD group (p = 0.75). Seventy-three percent of patients in the IVD group and 82% of patients in the No-IVD group achieved a ≥3-line improvement in visual acuity (p = 0.42). No significant difference was detected between the IVD and No-IVD groups for any of the three measures of inflammation.Conclusion: The use of IVD did not significantly improve the final median visual acuity, the chance of achieving a ≥3-line improvement in visual acuity, or the amount of intraocular inflammation. Based on these findings, and the possible detrimental effect of IVD on visual outcomes previously reported in the literature, the use of IVD does not appear to be warranted as a routine adjunctive treatment in postoperative endophthalmitis.Keywords: endophthalmitis, dexamethasone, intravitreal injectio

Mindfulness meditation targets transdiagnostic symptoms implicated in stress-related disorders: Understanding relationships between changes in mindfulness, sleep quality, and physical symptoms

Mindfulness-Based Stress Reduction (MBSR) is an 8-week meditation program known to improve anxiety, depression, and psychological well-being. Other health-related effects, such as sleep quality, are less well established, as are the psychological processes associated with therapeutic change. This prospective, observational study (n=213) aimed to determine whether perseverative cognition, indicated by rumination and intrusive thoughts, and emotion regulation, measured by avoidance, thought suppression, emotion suppression, and cognitive reappraisal, partly accounted for the hypothesized relationship between changes in mindfulness and two health-related outcomes: sleep quality and stress-related physical symptoms. As expected, increased mindfulness following the MBSR program was directly correlated with decreased sleep disturbance (r=-0.21, p=0.004) and decreased stress-related physical symptoms (r=-0.38, p<0.001). Partial correlations revealed that pre-post changes in rumination, unwanted intrusive thoughts, thought suppression, experiential avoidance, emotion suppression, and cognitive reappraisal each uniquely accounted for up to 32% of the correlation between the change in mindfulness and change in sleep disturbance and up to 30% of the correlation between the change in mindfulness and change in stress-related physical symptoms. Results suggest that the stress-reducing effects of MBSR are due, in part, to improvements in perseverative cognition and emotion regulation, two “transdiagnostic” mental processes that cut across stress-related disorders

Meta-Analysis of Maternal and Neonatal Outcomes Associated with the Use of Insulin Glargine versus NPH Insulin during Pregnancy

As glargine, an analog of human insulin, is increasingly used during pregnancy, a meta-analysis assessed its safety in this population. A systematic literature search identified studies of gestational or pregestational diabetes comparing use of insulin glargine with human NPH insulin, with at least 15 women in both arms. Data was extracted for maternal outcomes (weight at delivery, weight gain, 1st/3rd trimester HbA1c, severe hypoglycemia, gestation/new-onset hypertension, preeclampsia, and cesarean section) and neonatal outcomes (congenital malformations, gestational age at delivery, birth weight, macrosomia, LGA, 5 minute Apgar score >7, NICU admissions, respiratory distress syndrome, neonatal hypoglycemia, and hyperbilirubinemia). Relative risk ratios and weighted mean differences were determined using a random effect model. Eight studies of women using glargine (331) or NPH (371) were analyzed. No significant differences in the efficacy and safety-related outcomes were found between glargine and NPH use during pregnancy