878 research outputs found
Raising charitable children: the effects of verbal socialization and role-modeling on children’s giving
This paper uses nationally-representative data from the PSID and CDS to estimate the causal effects of two parent socialization actions—talking to children about giving and role-modeling—on children’s decisions whether or not to give to charity. We develop an identification framework based on the intra-household allocation and cultural transmission literatures that shows how different assumptions about parental response to time-varying unobserved changes in children’s prosocial values can be combined with the child fixed effects estimate and the difference between siblings’ over-time-differences estimate to infer a bound on the causal effect of parental action to socialize their children. Under the identifying assumption we think is most reasonable for socializing the willingness to give to charity, that parents treat the socialization actions of others as cultural substitutes, our estimates imply that talking to children about giving raises the probability of children’s giving by at least .13. We find no evidence that parental role-modeling affects children’s giving, except among non-African-American girls. The identification framework and substantive results have implications for those with a general interest in using data from naturalistic settings to estimate causal effects of parental socialization actions, those interested in the external validity of laboratory findings, and those interested in the socialization of warm glow
Evaluation of on-board hydrogen storage methods for hypersonic vehicles
Hydrogen is the foremost candidate as a fuel for use in high speed transport. Since any aircraft moving at hypersonic speeds must have a very slender body, means of decreasing the storage volume requirements below that for liquid hydrogen are needed. The total performance of the hypersonic plane needs to be considered for the evaluation of candidate fuel and storage systems. To accomplish this, a simple model for the performance of a hypersonic plane is presented. To allow for the use of different engines and fuels during different phases of flight, the total trajectory is divided into three phases: subsonic-supersonic, hypersonic and rocket propulsion phase. The fuel fraction for the first phase is found be a simple energy balance using an average thrust to drag ratio for this phase. The hypersonic flight phase is investigated in more detail by taking small altitude increments. This approach allowed the use of flight profiles other than the constant dynamic pressure flight. The effect of fuel volume on drag, structural mass and tankage mass was introduced through simplified equations involving the characteristic dimension of the plane. The propellant requirement for the last phase is found by employing the basic rocket equations. The candidate fuel systems such as the cryogenic fuel combinations and solid and liquid endothermic hydrogen generators are first screened thermodynamically with respect to their energy densities and cooling capacities and then evaluated using the above model
Thyroid stimulating hormone (TSH) concentrations and menopausal status in women at the mid-life: SWAN
objective We evaluated menopausal symptoms, menstrual cycle bleeding characteristics and reproductive hormones for their associations with thyroid stimulating hormone (TSH) concentrations in women at the mid-life from five ethnic groups. methods This report is from the baseline evaluation of the Study of Women's Health Across the Nation (SWAN), a community-based multiethnic study of the natural history of the menopausal transition. Enrollees were 42–52 years old (pre- and early perimenopausal) African American, Caucasian, Chinese, Hispanic and Japanese women ( n  = 3242). Enrollees were interviewed about self-reported diagnosed hypo- and hyperthyroidism or thyroid treatment, menopausal symptoms and menstrual cycle bleeding characteristics. Serum was assayed for TSH, oestradiol, testosterone, FSH and SHBG. results There were 6·2% of women with TSH > 5·0 mIU/ml and 3·2% with TSH  5·0 mIU/ml ( P  < 0·008) or < 0·5 mIU/ml ( P  < 0·02). Women with TSH values outside the range of 0·5–5·0 mIU/ml were more likely to report shorter or longer menstrual periods ( P  = 0·004 for both) than women within that range. FSH, SHBG, dehydroepiandrosterone sulphate (DHEA-S), testosterone, and oestradiol concentrations were not associated with TSH concentrations. conclusion In mid-aged women, there was a 9·6% prevalence of TSH values outside the euthyroid range of 0·5–5·0 mIU/ml. Although TSH was associated with bleeding length and self-reported fearfulness, it was not associated with indicators of the menopausal transition, including menopausal stage defined by bleeding regularity, menopausal symptoms or reproductive hormone concentrations.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73917/1/j.1365-2265.2003.01718.x.pd
The MINERA Data Acquisition System and Infrastructure
MINERA (Main INjector ExpeRiment -A) is a new few-GeV neutrino
cross section experiment that began taking data in the FNAL NuMI (Fermi
National Accelerator Laboratory Neutrinos at the Main Injector) beam-line in
March of 2010. MINERA employs a fine-grained scintillator detector capable
of complete kinematic characterization of neutrino interactions. This paper
describes the MINERA data acquisition system (DAQ) including the read-out
electronics, software, and computing architecture.Comment: 34 pages, 16 figure
Electrochemical Formation of Germanene: pH 4.5
Germanene is a single layer allotrope of Ge, with a honeycomb structure similar to graphene. This report concerns the electrochemical formation of germanene in a pH 4.5 solution. The studies were performed using in situ Electrochemical Scanning Tunneling Microscopy (EC-STM), voltammetry, coulometry, surface X-ray diffraction (SXRD) and Raman spectroscopy to study germanene electrodeposition on Au(111) terraces. The deposition of Ge is kinetically slow and stops after 2–3 monolayers. EC-STM revealed a honeycomb (HC) structure with a rhombic unit cell, 0.44 ± 0.02 nm on a side, very close to that predicted for germanene in the literature. Ideally the HC structure is a continuous sheet, with six Ge atoms around each hole. However, only small domains, surrounded by defects, of this structure were observed in this study. The small coherence length and multiple rotations domains made direct observation with surface X-ray diffraction difficult. Raman spectroscopy was used to investigate the multi-layer Ge deposits. A peak near 290 cm^(−1), predicted to correspond to germanene, was observed on one particular area of the sample, while the rest resembled amorphous germanium. Electrochemical studies of germanene showed limited stability when exposed to oxygen
- …