Effects of free stream turbulence, Reynolds number, and incidence angle on axial turbine cascade performance

A large-scale, low-speed, axial-turbine cascade was designed using a fast interactive design code and tested over a range of turbulence level and incidence angle for Reynolds numbers typically present in gas turbines. In all, 36 test conditions were examined;Testing was done primarily to investigate the profile boundary layer development under different inlet flow conditions. Glue-on hot-film gages and surface flow visualizations were used to identify transition and separation over the airfoil surface. In addition to transition measurements, overall cascade performance was determined from static pressure distributions on the airfoil and detailed five-hole pressure probe and hot-wire probe traverses in an exit plane of the cascade;The measured transition start and end points were compared against predictions using existing transition models. Also, the measured losses were compared against predicted losses from boundary layer calculations based on dissipation integral and finite difference analyses

Electron-spectroscopic investigation of metal-insulator transition in Sr2Ru1-xTixO4 (x=0.0-0.6)

We investigate the nature and origin of the metal-insulator transition in Sr2Ru1-xTixO4 as a function of increasing Ti content (x). Employing detailed core, valence, and conduction band studies with x-ray and ultraviolet photoelectron spectroscopies along with Bremsstrahlung isochromat spectroscopy, it is shown that a hard gap opens up for Ti content greater than equal to 0.2, while compositions with x<0.2 exhibit finite intensity at the Fermi energy. This establishes that the metal-insulator transition in this homovalent substituted series of compounds is driven by Coulomb interaction leading to the formation of a Mott gap, in contrast to transitions driven by disorder effects or band flling.Comment: Accepted for publication in Phys. Rev.

Primary Care Providers’ Judgments of Opioid Analgesic Misuse in a Community-Based Cohort of HIV-Infected Indigent Adults

BackgroundPrimary care providers (PCPs) must balance treatment of chronic non-cancer pain with opioid analgesics with concerns about opioid misuse.ObjectiveWe co-enrolled community-based indigent adults and their PCPs to determine PCPs’ accuracy of estimating opioid analgesic misuse and illicit substance use.DesignPatient-provider dyad study.ParticipantsHIV-infected, community-based indigent adults (‘patients’) and their PCPs.Main measuresUsing structured interviews, we queried patients on use and misuse of opioid analgesics and illicit substances. PCPs completed patient- and provider-specific questionnaires. We calculated the sensitivity, specificity, and measures of agreement between PCPs’ judgments and patients’ reports of opioid misuse and illicit substance use. We examined factors associated with PCPs’ thinking that their patients had misused opioid analgesics and determined factors associated with patients’ misuse.Key resultsWe had 105 patient-provider dyads. Of the patients, 21 had misused opioids and 45 had used illicit substances in the past year. The sensitivity of PCPs’ judgments of opioid analgesic misuse was 61.9% and specificity, 53.6% (Kappa score 0.09, p = 0.10). The sensitivity of PCPs’ judgments of illicit substance use was 71.1% and specificity, 66.7% (Kappa score 0.37, p &lt;0.001). PCPs were more likely to think that younger patients (Adjusted odds ratio (AOR) 0.89, 95% CI 0.84-0.97), African American patients (AOR 2.53, 95% CI 1.05-6.07) and those who had used illicit substances in the past year (AOR 3.33, 95% CI 1.35-8.20) had misused opioids. Younger (AOR 0.94, 95% CI 0.86-1.02) and African American (AOR 0.71, 95% CI 0.25-1.97) patients were not more likely to report misuse, whereas persons who had used illicit substances were (AOR 3.01, 95% CI 1.04-8.76).ConclusionPCPs’ impressions of misuse were discordant with patients’ self-reports of opioid analgesic misuse. PCPs incorrectly used age and race as predictors of misuse in this high-risk cohort

Purification and Biochemical Characterisation of Ricin from Castor Seeds

Ricin is a highly toxic plant toxin of Ricinus comtnunis seeds, commonly known as castor seeds. The toxin was extracted and purified using affinity and size exclusion  chromatography. The purity of ricin was evaluated by the sodium dodecylsulphate-polyacrylamide gel electrophoresis. Purified ricin gives a single band under non-reduced condition and two bands under reduced condition. The molecular weight of ricin was 65,0000 approx. The subunit structure of ricin on treatment with p-mercaptoethanol (1 %) at molecular level revealed that the reducing agent converts ricin into two peptides. The molecular weight of these two peptides was estimated to be 34000 and 32000. The western-blot analysis revealed two dots for its two peptides in 29 kDa to 36 kDa regions. The heamagglutination litres for ricin and Ricinus communis agglutinins were 1:8 and 1:256. The purity of purified ricin was further confirmed by the electrophoresis and the western-blot analysis. The Indian variety of castor seeds, known as Ricinus communis used in this study, contains approx. 0.12 per cent ricin

Haematological and Biochemical Changes in Response to Stress Induced by the Administration of Amikacin Injection by Autoinjector in Animals

The drugs administered by autoinjectors, may act fast reducing the morbidity and mortality in critical and emergency situations. Amikacin drug cartridge was developed for the autoinjector as an antibacterial drug for critical situations and its tolerability was studied. Rats were given either 3 doses or 7 doses on consecutive days by the autoinjector (intraperitoneal, 63 mg/mL). Blood was withdrawn on the 4th day (3 doses) or the 8th day (7 doses), and haematological and biochemical parameters were studied. All the parameters studied were within the limits and did not show any significant difference when compared with the control. Rabbits were given 3 doses of two concentrations (intramuscular, 63 or 250 mg/mL) and on the 4th day blood was withdrawn for the haematological and biochemical estimations. 63 mg/mL cartridge did not show any significant change while 250 mg/mL cartridge showed significant change in the haematological and biochemical parameters. This study showed that intraperitoneal injection of amikacin by the autoinjector designed for intramuscular injection was well tolerated by the rats. In the rabbits, low dose (63 mg/mL) was tolerated while the higher dose, which is an adult human dose (250 mg/mL) showed significant changes.Defence Science Journal, 2014, 64(2), pp. 99-105. DOI: http://dx.doi.org/10.14429/dsj.64.503

Preparation and Characterization of 3 nm Magnetic NiAu Nanoparticles

Using PAMAM dendrimers as nanoparticle templates, a synthetic route to prepare 3 nm magnetic NiAu nanoparticles was developed. Aqueous solutions of hydroxyl-terminated generation 5 PAMAM dendrimers in 25 mM NaClO4 were shown to bind aqueous NiII. Coreduction of NiII and AuIII salts yielded bimetallic dendrimer stabilized nanoparticles, which were extracted into toluene with decanethiol. Characterization of the resulting monolayer protected clusters (MPCs) with transmission electron microscopy and UV-visible, atomic absorption, and X-ray photoelectron spectroscopies suggested that the MPCs had substantial surface enrichment in Au. Superconducting quantum interference device (SQUID) measurements at 5 K show the bimetallic MPCs to have low coercivity and saturation magnetization relative to bulk Ni. Solution nuclear magnetic resonance (NMR) studies using the Evans method showed the bimetallic nanoparticles retain magnetic properties at ambient temperatures

Quaternary borocarbides: New class of intermetallic superconductors

Our recent discovery of superconductivity (SC) in the four-element multiphase Y-Ni-B-C system at an elevated temperature (TC approximately 12 K) has opened up great possibilities of identifying new superconducting materials and generating new physics. Superconductivity with Tc (greater than 20 K) higher than that known so far in bulk intermetallics has been observed in multiphase Y-Pd-B-C and Th-Pd-B-C systems and a family of single phase materials RENi2B2C (RE= Y, rare earth) have been found. Our investigations show YNi2B2C to be a strong coupling hard type-II SC. HC2(T) exhibits an unconventional temperature dependence. Specific heat and magnetization studies reveal coexistence of SC and magnetism in RNi2B2C (R = Ho, Er, Tm) with magnetic ordering temperatures (Tc approximately 8 K, 10.5 K, 11 K and Tm approximately 5 K, approximately 7K, approximately 4 K respectively) that are remarkably higher than those in known magnetic superconductors . Mu-SR studies suggest the possibility of Ni atoms carrying a moment in TmNi2B2C. Resistivity results suggests a double re-entrant transition (SC-normal-SC) in HoNi2B2C. RENi2B2C (RE = Ce, Nd, Gd) do not show SC down to 4.2 K. The Nd- and Gd-compounds order magnetically at approximately 4.5 K and approximately 19.5 K, respectively. Two SC transitions are observed in Y-Pd-B-C (Tc approximately 22 K, approximately 10 K) and in Th-Pd-B-C (Tc approximately 20 K, approximately 14 K) systems, which indicate that there are at least two structures which support SC in these borocarbides. In our multiphase ThNi2B2C we observe SC at approximately 6 K. No SC was seen in multiphase UNi2B2C, UPd2B2C, UOs2Ge2C and UPd5B3C(0.35) down to 4.2 K. Tc in YNi2B2C is depressed by substitutions (Gd, Th and U at Y-sites and Fe, Co at Ni-sites)