A Study of Transparent Plastics for use on Aircraft. Supplement

This supplement to a NACA study issued in May 1937 entitled "A Study of Transparent Plastics for Use on Aircraft", contains two tables. These tables contain data on bursting strengths of plastics, particularly at low temperatures. Table 1 contains the values reported in a table of the original memorandum, and additional values obtained at approximately 25 C, for three samples of Acrylate resin. The second table contains data obtained for the bursting strength when one surface of the plastic was cooled to approximately -35 C

Resistance of Transparent Plastics to Impact

The problem of developing a windshield for aircraft which will withstand the effect of bird impacts during flight is a difficult one, as an estimate of the striking energy will indicate. If the average speed of the airplane is considered to be about 200 miles per hour and that of the bird about 70 miles per hour, the speed of the bird relative to the airplane may be as great as 400 feet per second. If a 4-pound bird is involved, a maximum impact energy of approximately 10,000 foot-pounds must be dissipated. To obtain this energy in a drop test in the Washington Monument, it would be necessary to drop a 20-pound weight down the 500-foot shaft. For both theoretical and practical reasons, it is necessary to keep the mass and speed more nearly like those to be encountered. However, to get an impact of about 10,000 foot-pounds with a 4-pound falling body, it would be necessary to drop it from a height of approximately one-half mile, neglecting air resistance. These facts will indicate some of the experimental obstacles in the way of simulating bird impacts against aircraft windshields

Assessment of the revised Difficulties in Emotion Regulation Scales among adolescents and adults with severe mental illness

The Difficulties in Emotion Regulation Scale (DERS) comprising 36 items has been widely used across age, gender, psychopathology, language, and culture. Recently several alternative abridged forms have been introduced, namely, the DERS-16 (Bjureberg et al. 2016), the DERS-SF (Kaufman et al. 2016), and the DERS-18 (Victor and Klonsky, 2016), each composed of 16 or 18 items, to provide researchers and clinicians with a shorter measure of emotion dysregulation. However, no study to date has directly compared the psychometrics of these alternative forms. In the present study, using confirmatory factor analysis we first examined the factor structure of the four models of the DERS in two inpatient samples of 636 adolescents in the age-range of 12–17 years (M = 15.33, SD = 1.43), and 1807 adults in the age-range of 18–76 years (M = 34.86, SD = 14.63) with severe mental illness. Next, measurement invariance was tested comparing the two age groups across the four models of DERS. Only the DERS-SF established metric and scalar measurement invariance. Findings suggest that the factor structure of the original and the abridged models of DERS have acceptable fit, however only DERS-SF had equivalence of factor loadings and item intercepts across adolescents and adults

Differential Interferometric Measurement of Instability at Two Points in a Hypervelocity Boundary Layer

The focused laser differential interferometer (FLDI) was used to investigate disturbances in a hypervelocity boundary layer on a sharp five degree half-angle cone. The T5 hypervelocity free-piston driven reflected-shock tunnel was used as the test facility; in such a facility the study of thermo-chemical/fluid-dynamic energy exchange is emphasized. Two sensitive FLDI probe volumes were aligned along a generator of the cone that recorded time-traces of density fluctuation at sufficient time resolution, spatial resolution, and signal to noise ratio, so that the boundary layer instability could be resolved. This arrangement of the FLDI allows for the interpretation of disturbances at two points and the correlation between them. The acoustic instability is detected with narrow-band peaks in the spectral response at a number of frequencies (500 kHz to 1.29 MHz). The data indicate that the instability driving the boundary layer to turbulence is acoustic in nature. Preliminary analysis indicates that there is not a significant difference between N2 and air acoustic boundary layer disturbance amplification factors for the representative cases presented. Computation of acoustic damping by thermo-chemical relaxation processes is presented for the same representative cases, and indicates that there is a negligible amount of absorption for both air and N_2 at the observed disturbance frequencies

How and When Socially Entrepreneurial Nonprofit Organizations Benefit From Adopting Social Alliance Management Routines to Manage Social Alliances?

Social alliance is defined as the collaboration between for-profit and nonprofit organizations. Building on the insights derived from the resource-based theory, we develop a conceptual framework to explain how socially entrepreneurial nonprofit organizations (SENPOs) can improve their social alliance performance by adopting strategic alliance management routines. We test our framework using the data collected from 203 UK-based SENPOs in the context of cause-related marketing campaign-derived social alliances. Our results confirm a positive relationship between social alliance management routines and social alliance performance. We also find that relational mechanisms, such as mutual trust, relational embeddedness, and relational commitment, mediate the relationship between social alliance management routines and social alliance performance. Moreover, our findings suggest that different types of social alliance motivation can influence the impact of social alliance management routines on different types of the relational mechanisms. In general, we demonstrate that SENPOs can benefit from adopting social alliance management routines and, in addition, highlight how and when the social alliance management routines–social alliance performance relationship might be shaped. Our study offers important academic and managerial implications, and points out future research directions

Gravitational Waves From Known Pulsars: Results From The Initial Detector Era

We present the results of searches for gravitational waves from a large selection of pulsars using data from the most recent science runs (S6, VSR2 and VSR4) of the initial generation of interferometric gravitational wave detectors LIGO (Laser Interferometric Gravitational-wave Observatory) and Virgo. We do not see evidence for gravitational wave emission from any of the targeted sources but produce upper limits on the emission amplitude. We highlight the results from seven young pulsars with large spin-down luminosities. We reach within a factor of five of the canonical spin-down limit for all seven of these, whilst for the Crab and Vela pulsars we further surpass their spin-down limits. We present new or updated limits for 172 other pulsars (including both young and millisecond pulsars). Now that the detectors are undergoing major upgrades, and, for completeness, we bring together all of the most up-to-date results from all pulsars searched for during the operations of the first-generation LIGO, Virgo and GEO600 detectors. This gives a total of 195 pulsars including the most recent results described in this paper.United States National Science FoundationScience and Technology Facilities Council of the United KingdomMax-Planck-SocietyState of Niedersachsen/GermanyAustralian Research CouncilInternational Science Linkages program of the Commonwealth of AustraliaCouncil of Scientific and Industrial Research of IndiaIstituto Nazionale di Fisica Nucleare of ItalySpanish Ministerio de Economia y CompetitividadConselleria d'Economia Hisenda i Innovacio of the Govern de les Illes BalearsNetherlands Organisation for Scientific ResearchPolish Ministry of Science and Higher EducationFOCUS Programme of Foundation for Polish ScienceRoyal SocietyScottish Funding CouncilScottish Universities Physics AllianceNational Aeronautics and Space AdministrationOTKA of HungaryLyon Institute of Origins (LIO)National Research Foundation of KoreaIndustry CanadaProvince of Ontario through the Ministry of Economic Development and InnovationNational Science and Engineering Research Council CanadaCarnegie TrustLeverhulme TrustDavid and Lucile Packard FoundationResearch CorporationAlfred P. Sloan FoundationAstronom

Parenting practice, leisure experience, and substance use among South African adolescents

There is limited understanding of parents’ role in positive youth/adolescent development through leisure in developing countries. Using a sample of 6,626 eighth-grade students in South Africa, this study examined the interrelationships among parenting practice, adolescents’ leisure experience, and substance use. Results of structural equation modeling showed that parental leisure involvement was associated with less substance use, while parental leisure overcontrol was associated with greater substance use. The relationship of parental leisure involvement to substance use was mediated by healthy leisure engagement. The relationship of parental leisure overcontrol to substance use, on the other hand, was mediated by leisure boredom and healthy leisure engagement. The model path coefficients had little variation between genders and socioeconomic groups except that parental leisure overcontrol had a stronger positive relationship with leisure boredom for males than for females. Theoretical and practical implications are discussed

Disease-Related Cardiac Troponins Alter Thin Filament Ca2+ Association and Dissociation Rates

The contractile response of the heart can be altered by disease-related protein modifications to numerous contractile proteins. By utilizing an IAANS labeled fluorescent troponin C, , we examined the effects of ten disease-related troponin modifications on the Ca2+ binding properties of the troponin complex and the reconstituted thin filament. The selected modifications are associated with a broad range of cardiac diseases: three subtypes of familial cardiomyopathies (dilated, hypertrophic and restrictive) and ischemia-reperfusion injury. Consistent with previous studies, the majority of the protein modifications had no effect on the Ca2+ binding properties of the isolated troponin complex. However, when incorporated into the thin filament, dilated cardiomyopathy mutations desensitized (up to 3.3-fold), while hypertrophic and restrictive cardiomyopathy mutations, and ischemia-induced truncation of troponin I, sensitized the thin filament to Ca2+ (up to 6.3-fold). Kinetically, the dilated cardiomyopathy mutations increased the rate of Ca2+ dissociation from the thin filament (up to 2.5-fold), while the hypertrophic and restrictive cardiomyopathy mutations, and the ischemia-induced truncation of troponin I decreased the rate (up to 2-fold). The protein modifications also increased (up to 5.4-fold) or decreased (up to 2.5-fold) the apparent rate of Ca2+ association to the thin filament. Thus, the disease-related protein modifications alter Ca2+ binding by influencing both the association and dissociation rates of thin filament Ca2+ exchange. These alterations in Ca2+ exchange kinetics influenced the response of the thin filament to artificial Ca2+ transients generated in a stopped-flow apparatus. Troponin C may act as a hub, sensing physiological and pathological stimuli to modulate the Ca2+-binding properties of the thin filament and influence the contractile performance of the heart

Deprived or not deprived? Comparing the measured extent of material deprivation using the UK government's and the Poverty and Social Exclusion surveys' method of calculating material deprivation

Poverty can either be measured directly, through standards of living such as material deprivation, or indirectly through resources available, usually income. Research shows that the optimum measure of poverty combines these methods, a fact that the UK government took cognisance of in its tripartite measure of child poverty. For use in a birth cohort study, two methods of calculating material deprivation were tested: the method used by the UK government taken from the Family Resources Survey (FRS), and the methods used in the Poverty and Social Exclusion (PSE) study at Bristol University. Results show that the former measure, compared to the latter measure, underestimates the depth and extent of material deprivation among families with young children in Scotland