623 research outputs found
Effect of Burning Rate Modifiers on Subatmospheric Flame Temperatures of AP/HTPB Composite Solid Propellants
Using 30 um. pt and Pt 13 percent Rh thermocouples, flame temperatures of uncatalysed andcatalysed ammonium perchlorate/hydroxyl-terminated polybutadiene (AP/lffPB) composite solidpropellants were measured under subatmospheric conditions. Ferric oxide F e 2 and copper chromite(CC) were the catalysts used. The study demonstrates that Fe2O3 catalysed propellant, notwithstandingits least combustion efficiency undt;r subatmospheric conditions and weak gas-phase flame, has themaximum burning rate enhancement. This is argued to be due to the increased surface and subsurfacereactions caused by Fe2O3. CC-catalysed propellant burns to the least subatmospheric pressure withminimum loss in combustion efficiency indicating that this class of propellant may be more suitablefor base-bleed applications
Stochastic Geometric Modeling & Analysis of Non-Uniform Two-tier Networks: A Stienen’s Model Base Approach
While stochastic geometric models based on Poisson point processes (PPP) provide a tractable approach for the analysis of uniform two-tier network deployments, the performance evaluation of a non-uniform deployment remains an open issue which we address in this paper. This is due to the fact that smaller cells can be more efficiently deployed in areas where the QoS of traditional macro base stations is poor. Therefore, in this paper we introduce Stienen’s model which allows us to analyse such non-uniform deployment. In contrast to traditional PPP based analysis, performance characterization under Stienen Model are more challenging due to location and density dependencies. However, we demonstrate that the performance can be approximated in a tractable manner. The developed statistical framework is employed to characterize the gains in terms of energy efficiency (EE) for non-uniform deployments. Results show an achievable 19% to 124% improvements in the macrocell coverage as compared to a uniform deployment, while the femtocell coverage and system EE are of the same order of magnitude for both deployments. These results are complemented with the fact that OPEX and CAPEX are reduced due to a lesser number of FAPs deployed
DESIGN AND EVALUATION OF NOVEL TOPICAL GEL OF TINOSPORA CORDIFOLIA AS ANTIMICROBIAL AGENT
Objective: The present study deals with topical formulations of a bioactive extract of Tinospora cordifolia and its evaluation.Methods: Dried, powdered stem was extracted with chloroform using ultra-sonication method for 3 hrs. Topical formulations like gels containingchloroform extract were formulated using various gelling agents. These gels were evaluated for physicochemical parameters, viscosity, spreadaibility,and antimicrobial activity.Results: A topical gel was successfully formulated containing bioactive chloroform extract of T. cordifolia. The gel was very effective as antimicrobialformulations.Conclusion: These kinds of formulations can be very promising wound healing medicines with ease of use and no side effects.Keywords: Topical gel, Tinospora Cordifolia, Anitmictobia
Men’s oppressive beliefs predict their breast size preferences in women
Previous studies of men’s breast size preferences have yielded equivocal findings, with studies variously indicating a preference for small, medium, or large breasts. Here, we examined the impact of men’s oppressive beliefs in shaping their female breast size ideals. British White men from the community in London, England (N = 361) viewed figures of women that rotated in 360° and varied in breast size along five levels. They then rated the figure that they found most physically attractive and also completed measures assessing their sexist attitudes and tendency to objectify women. Results showed that medium breasts were rated most frequent as attractive (32.7 %), followed by large (24.4 %) and very large (19.1 %) breasts. Further analyses showed that men’s preferences for larger female breasts were significantly associated with a greater tendency to be benevolently sexist, to objectify women, and to be hostile towards women. These results were discussed in relation to feminist theories, which postulate that beauty ideals and practices in contemporary societies serve to maintain the domination of one sex over the other
An examination of the factorial and convergent validity of four measures of conspiracist ideation, with recommendations for researchers
A number scales have been developed to measure conspiracist ideation, but little attention has been paid to the factorial validity of these scales. We reassessed the psychometric properties of four widely-used scales, namely the Belief in Conspiracy Theories Inventory (BCTI), the Conspiracy Mentality Questionnaire (CMQ), the Generic Conspiracist Beliefs Scale (GCBS), and the One-Item Conspiracy Measure (OICM). Eight-hundred-and-three U. S. adults completed all measures, along with measures of endorsement of 9/11 and anti- vaccination conspiracy theories. Through both exploratory and confirmatory factor analysis, we found that only the BCTI had acceptable factorial validity. We failed to confirm the factor structures of the CMQ and the GBCS, suggesting these measures had poor factorial valid- ity. Indices of convergent validity were acceptable for the BCTI, but weaker for the other measures. Based on these findings, we provide suggestions for the future refinement in the measurement of conspiracist ideation
Resource security impacts men’s female breast size preferences
It has been suggested human female breast size may act as signal of fat reserves, which in turn indicates access to resources. Based on this perspective, two studies were conducted to test the hypothesis that men experiencing relative resource insecurity should perceive larger breast size as more physically attractive than men experiencing resource security. In Study 1, 266 men from three sites in Malaysia varying in relative socioeconomic status (high to low) rated a series of animated figures varying in breast size for physical attractiveness. Results showed that men from the low socioeconomic context rated larger breasts as more attractive than did men from the medium socioeconomic context, who in turn perceived larger breasts as attractive than men from a high socioeconomic context. Study 2 compared the breast size judgements of 66 hungry versus 58 satiated men within the same environmental context in Britain. Results showed that hungry men rated larger breasts as significantly more attractive than satiated men. Taken together, these studies provide evidence that resource security impacts upon men’s attractiveness ratings based on women’s breast size
Mental health literacy of depression: gender differences and attitudinal antecedents in a representative British sample
Background
Poor mental health literacy and negative attitudes toward individuals with mental health disorders may impede optimal help-seeking for symptoms of mental ill-health. The present study examined the ability to recognize cases of depression as a function of respondent and target gender, as well as individual psychological differences in attitudes toward persons with depression.
Methods
In a representative British general population survey, the ability to correctly recognize vignettes of depression was assessed among 1,218 adults. Respondents also rated the vignettes along a number of attitudinal dimensions and completed measures of attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes.
Results
There were significant differences in the ability to correctly identify cases of depression as a function of respondent and target gender. Respondents were more likely to indicate that a male vignette did not suffer from a mental health disorder compared to a female vignette, and women were more likely than men to indicate that the male vignette suffered from a mental health disorder. Attitudes toward persons with depression were associated with attitudes toward seeking psychological help, psychiatric skepticism, and anti-scientific attitudes.
Conclusion
Initiatives that consider the impact of gender stereotypes as well as individual differences may enhance mental health literacy, which in turn is associated with improved help-seeking behaviors for symptoms of mental ill-health
Precise Modeling of Solar Radiation Pressure for IRNSS Satellite
IRNSS-1A, IRNSS-1B and IRNSS-1C are the first three satellites of Indian Regional Navigation Satellite System (IRNSS) launched in 1st July 2013,4th April 2014 and 16th October 2014 respectively. IRNSS will provide regional navigation services independently over the IRNSS service area. For the precise positioning and navigation applications, precise orbit and clock information of the IRNSS satellites are essential. For High altitude satellites like IRNSS, Solar Radiation Pressure (SRP) force is the second largest perturbation force acting on the satellites after the gravitational attraction from Earth, Sun and Moon. It is the largest error source in the modelling of orbital dynamics of IRNSS, and hence its precise modelling is essential for accurate orbit determination. In this paper different approaches were studied to develop a highly precise solar radiation pressure model for IRNSS satellites using IRNSS-1A and IRNSS-1B observation data. Since IRNSS satellites shape, optical properties, physical properties as well as the attitude information are different from other Indian Communication satellites, a novel approach has been adopted here for precise modelling of SRP. The force due to SRP has been computed analytically for each of the spacecraft surfaces in the satellite body fixed frame which is further resolved in all required directions to compute the net force. To evaluate the performance of the SRP model, the orbit accuracy is derived from 1-day orbit overlaps at day boundaries of 2-day solutions. As a result, an orbit estimation accuracy of 25 meters has been observed by the model alone, while the estimation error is observed as 2.5m.Further beside the model, 3 constant co-efficient has been estimated in the three particular directions (namely DYB) which were following a right handed system. Again the model performance with estimated co-efficient has been analysed and the orbit accuracy is derived from the overlap test. As a result, an orbit estimation accuracy of 10 m has been observed, while the estimation error is about 1m. Keywords: IRNSS, Navigation, Solar Radiation Pressure, orbit accurac
Dehumidification Enhancement of Direct Expansion Systems Through Component Augmentation of the Cooling Coil
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