1,194 research outputs found
Spherical shield Patent
Flexible bellows joint shielding sleeve for propellant transfer pipeline
Study of polytropes with Generalized polytropic Equation of State
The aim of this paper is to discuss the theory of Newtonian and relativistic
polytropes with generalized polytropic equation of state. For this purpose, we
formulated the general framework to discuss the physical properties of
polytrops with anisotropic inner fluid distribution under conformally flat
condition in the presence of charge. We investigate the stability of these
polytrops in the vicinity of generalized polytropic equation through
Tolman-mass. It is concluded that one of the derived models is physically
acceptable.Comment: 21 pages, 3 figure
Thermal and velocity slip effects on the MHD peristaltic flow with carbon nanotubes in an asymmetric channel: application of radiation therapy
Peristaltic Flow with Inclined Magnetic Field and Convective Boundary Conditions
Peristaltic flow of viscous fluid in an asymmetric inclined channel with heat transfer and inclined magnetic field is examined. The convective boundary conditions have been handled. Complexity of emerging equations is simplified by utilizing long wavelength and low Reynolds number approximation. Variation of emerging parameters embedded in flow system are discussed. It is observed that an increase in Brikman number increases the temperature profile. Further, it is seen that temperature distribution is an increasing function of Biot number at lower wall
Comparison of various oxidative treatments for removal of reactive black CNN
Decolorization of reactive black CNN by chemical oxidation and reduction using KMnO4, H2O2 and Ferrioxalate as oxidizing agents and Na2SO3 as reducing agent individually as well as in combination was studied on batch scale using UV-visible spectroscopy. Degradation of dye occurred in acidic medium with KMnO4 and in alkaline medium with H2O2 and ferrioxalate. The most efficient methods for decolorization of reactive black CNN is oxidation using KMnO4 as an oxidizing agent which removed 97.64% of dye. Maximum decolorization was obtained at 60 min of treatment under static conditions. H2O2 and ferrioxalate could remove only 50.71 and 44.21% dye, respectively. Sequential treatment was more successful with H2O2 and ferrioxalate when compared with KMnO4. Chemical oxygen demand (COD) and total organic carbon (TOC) contents of treated wastewater decreased appreciably from 83.6 to 63.7 mg/L and 86.8 to 72.8 mg/L, respectively. Additionally, Fourier Transform Infrared Spectroscopy (FTIR) study revealed the degradation of reactive black CNN after treatment into non toxic products.Keywords: Reactive black CNN, KMnO4, ferrioxalate, sodium sulphite, chemical oxygen demand (COD)
The Deep Space Network: A Radio Communications Instrument for Deep Space Exploration
The primary purpose of the Deep Space Network (DSN) is to serve as a communications instrument for deep space exploration, providing communications between the spacecraft and the ground facilities. The uplink communications channel provides instructions or commands to the spacecraft. The downlink communications channel provides command verification and spacecraft engineering and science instrument payload data
Numerical study of Williamson nano fluid flow in an asymmetric channel
AbstractThis article investigates with the peristaltic flow of a Williamson nano fluid in an asymmetric channel. The related modeling of the problem has been done in Cartesian coordinate system. Problem has been simplified with the reliable assumptions i.e. long wave length and small Reynolds number. Numerical solutions have been evaluated for stream function, velocity profile, temperature profile, nano particle phenomena and pressure rise. Graphical results have been presented and discussed for various involved parameters
Cutaneous leishmaniasis in Karak, Pakistan: Report of an outbreak and comparison of diagnostic techniques
A total of 339 patients with clinically suspected cutaneous leishmaniasis (CL) were studied from March to April, 2010 in three villages of Karak, Khyber Pakhtunkhwa, Pakistan where an epidemic of the disease was in question. Using polymerase chain reaction (PCR), 78.17% (265/339) were observed having CL. Microscopically, however, only 43.06% (146/339) were diagnosed with the disease. This study reports and confirms epidemic of CL in both gender of all ages in the area. Females (70.94%) were noted to be predominantly affected as compared to males (29%). Clinically, 12.38% of patients had more than three lesions, 29.20% had two lesions, while 58.40% had only single lesion. Most lesions were found on exposed surfaces of the body (predominantly hands, face and feet). The present study confirms that PCR was more sensitive than microscopic examination.Key words: Epidemic, cutaneous leishmaniasis, polymerase chain reaction (PCR), microscopy, Pakistan
Reliability and validity of the Safe Routes to school parent and student surveys
Abstract Background The purpose of this study is to assess the reliability and validity of the U.S. National Center for Safe Routes to School's in-class student travel tallies and written parent surveys. Over 65,000 tallies and 374,000 parent surveys have been completed, but no published studies have examined their measurement properties. Methods Students and parents from two Charlotte, NC (USA) elementary schools participated. Tallies were conducted on two consecutive days using a hand-raising protocol; on day two students were also asked to recall the previous days' travel. The recall from day two was compared with day one to assess 24-hour test-retest reliability. Convergent validity was assessed by comparing parent-reports of students' travel mode with student-reports of travel mode. Two-week test-retest reliability of the parent survey was assessed by comparing within-parent responses. Reliability and validity were assessed using kappa statistics. Results A total of 542 students participated in the in-class student travel tally reliability assessment and 262 parent-student dyads participated in the validity assessment. Reliability was high for travel to and from school (kappa > 0.8); convergent validity was lower but still high (kappa > 0.75). There were no differences by student grade level. Two-week test-retest reliability of the parent survey (n = 112) ranged from moderate to very high for objective questions on travel mode and travel times (kappa range: 0.62 - 0.97) but was substantially lower for subjective assessments of barriers to walking to school (kappa range: 0.31 - 0.76). Conclusions The student in-class student travel tally exhibited high reliability and validity at all elementary grades. The parent survey had high reliability on questions related to student travel mode, but lower reliability for attitudinal questions identifying barriers to walking to school. Parent survey design should be improved so that responses clearly indicate issues that influence parental decision making in regards to their children's mode of travel to school
(U-th)/he ages from the fuorite mineralization of the Tanguá Alkaline intrusion
The Tanguá Alkaline Suite formed as a result of Mesozoic to Cenozoic magmatic events that affected the part of the South American Platform in Brazil’s southeast. The alkaline intrusion is composed of alkali-feldspar syenite with nepheline (pulaskites and umptekites), syenite (with or without the presence of pseudo-leucite), varied nepheline syenites (foyaites, micro-foyaites etc.) and alkaline magmatic breccias. The intrusion contains important fluorite mineralization, in the form of NE-SW oriented veins, which were economically extracted in recent decades at the Emitang Mine. This paper focuses on the analysis of these centimetric crystals of fluorite which vary in color from (yellow, to white and pur-ple.) associated with mineralization of Tanguá Body. Geochronological dating by (U-Th)/He of fluorite mineralization showed a wide range of ages, with the oldest age of 74 ± 3 Ma (Late Cretaceous) and the youngest of 0.11 ± 0.02 Ma (Late Pleistocene). Most ages are concentrated between 25 and 8 Ma (Miocene). The oldest age (74.0 ± 3 Ma) is associated with hydrothermal fluids percolating at the time of intrusion of the Tanguá Body. The other ages represent episodes of percolation of hydrothermal fluids and consequent growth of fluorite crystals. Of note is a set of Miocene ages that can be associated with regional tectonic events. This phase of flurite growth may be associated with the reactivation of basement faults and structures in the Tanguá region and the circulation of hydrothermal fluids associated with intrusion of younger dikes. The youngest ages may be associated with neotectonic reactivation of faults during neotectonic events
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