An Initial Study of Ultraordnance Impact Experiments on Concrete

Author(s):  
George H. Vankirk ◽  
Jesse A. Sherburn ◽  
William F. Heard ◽  
Erik M. Chappell
2000 ◽  
Vol 43 (2) ◽  
pp. 32-37
Author(s):  
Robert Roybal ◽  
Pawel Tlomak ◽  
Charles Stein ◽  
P. Stokes

Increasing demands on the design criteria of spacecraft components have driven efforts to develop advanced space debris ground simulation techniques suitable to be incorporated into a space environmental effects chamber. A laser-driven flyer method suitable in such a chamber was used to conduct an initial investigation of space debris impact on a new toughened solar cell coverglass material. Damage characteristics, including mechanical damage and contamination generated by impact with a 3-mm diameter, 3-μm thick aluminum particle accelerated to 4.5 km/sec, were investigated. Scanning electron microscopy, optical microscopy, and spectrophotometry were used to measure the mechanical damage and the loss of solar transmission. Because of the limited number of impact tests made in this initial study, a quantitative analysis was not possible. However, much insight was obtained from the observed damage.


Author(s):  
D.R. Jackson ◽  
J.H. Hoofnagle ◽  
A.N. Schulman ◽  
J.L. Dienstag ◽  
R.H. Purcell ◽  
...  

Using immune electron microscopy Feinstone et. al. demonstrated the presence of a 27 nm virus-like particle in acute-phase stools of patients with viral hepatitis, type A, These hepatitis A antigen (HA Ag) particles were aggregated by convalescent serum from patients with type A hepatitis but not by pre-infection serum. Subsequently Dienstag et. al. and Maynard et. al. produced acute hepatitis in chimpanzees by inoculation with human stool containing HA Ag. During the early acute disease, virus like particles antigenically, morphologically and biophysically identical to the human HA Ag particle were found in chimpanzee stool. Recently Hilleman et. al. have described similar particles in liver and serum of marmosets infected with hepatitis A virus (HAV). We have investigated liver, bile and stool from chimpanzees and marmosets experimentally infected with HAV. In an initial study, a chimpanzee (no.785) inoculated with HA Ag-containing stool developed elevated liver enzymes 21 days after exposure.


1998 ◽  
Vol 14 (3) ◽  
pp. 226-233 ◽  
Author(s):  
Jürgen Hoyer ◽  
Mechthild Averbeck ◽  
Thomas Heidenreich ◽  
Ulrich Stangier ◽  
Karin Pöhlmann ◽  
...  

Epstein's “Constructive Thinking Inventory” (CTI) was developed to measure the construct of experiential intelligence, which is based on his cognitive-experiential self-theory. Inventory items were generated by sampling naturally occurring automatic cognitions. Using principal component analysis, the findings showed a global factor of coping ability as well as six main factors: Emotional Coping, Behavioral Coping, Categorical Thinking, Personal Superstitious Thinking, Esoteric Thinking, and Naive Optimism. We tested the replicability of this factor structure and the amount of statistical independence (nonredundancy) between these factors in an initial study of German students (Study 1, N = 439) and in a second study of patients with chronic skin disorders (Study 2, N = 187). Factor congruence with the original (American) data was determined using a formula proposed by Schneewind and Cattell (1970) . Our findings show satisfactory factor congruence and statistical independence for Emotional Coping and Esoteric Thinking in both studies, while full replicability or independence could not be found in both for the other factors. Implications for the use and further development of the CTI are discussed.


Author(s):  
Nusa FAIN ◽  
Michel ROD ◽  
Erik BOHEMIA

This paper explores the influence of teaching approaches on entrepreneurial mindset of commerce, design and engineering students across 3 universities. The research presented in this paper is an initial study within a larger project looking into building ‘entrepreneurial mindsets’ of students, and how this might be influenced by their disciplinary studies. The longitudinal survey will measure the entrepreneurial mindset of students at the start of a course and at the end. Three different approaches to teaching the courses were employed – lecture and case based, blended online and class based and fully project-based course. The entrepreneurial mindset growth was surprisingly strongest within the engineering cohort, but was closely followed by the commerce students, whereas the design students were slightly more conservative in their assessments. Future study will focus on establishing what other influencing factors beyond the teaching approaches may relate to the observed change.


2020 ◽  
pp. 43-50
Author(s):  
N.V. Didenkul ◽  

According to recent studies, in the vitamin D deficiency state (VDD), pregnancy can be complicated and the optimal level of VD in the blood is one of the conditions for the realization of reproductive potential. The objective: the possibility to preventing calcitriol-associated pregnancy complications by the correcting VD deficiency at the preconception period. Materials and methods. 57 women with VDD were examined. A history of all women had a pregnancy complicated by placental dysfunction (PD); 27 of them were observed from the preconception period (main group – IA) and 30 – from the 1st trimester of pregnancy (comparison group – IB). The VD status by the blood level of the 25-hydroxyvitamin D by ELISA was determined. Women of both groups, in addition to the vitamin-mineral complex (VMC) were prescribed supplementation colecalciferol at a dose of 4.000 IU per day. Pregnant women of both groups received VMCs up to 16 weeks. After optimizing the level (3–4 months), women continued to take VD at a dose of 2.000 IU per day throughout pregnancy. Results. At the initial study, the VD level was 15.72±2.59 ng/ml in ІА and 16.1±1.99 ng/ml in ІВ group (U=883; p>0.05); after treatment increased to 38.31±3.29 ng/ml and 36.13±2.99 ng/ml (U=900; p>0.05). In group IA, the course of pregnancy was characterized by a lower frequency of complications: PD was diagnosed in 22.2% in group IA and 50% in group IB (F=0.0001; p<0.01); fetal distress in 3.7% and 10% (F=0.16; p<0.05): signs of amnionitis – in 18.5% and 33.3% (F=0.035; p<0.05); placental hypertrophy or hypotrophy – in 7.4% and 36.7% (F=0.00001; p<0.01), preeclampsia in 3.7% and 6.7% of women (F=0,54; p<0.05). The frequency of cesarean section in the comparison group was significantly higher (40% VS 25.9%, F=0.034; p<0.05). Conclusions. During pregnancy, which occurred in conditions of VDD, the frequency of some pregnancy complications, including preeclampsia, the threat of miscarriage, placental dysfunction was in 2–4 times higher than in women with optimized VD status. One of the directions of the individual management plan for women with a negative obstetric history can be the determination of the level of VD in the blood and correction of the VDD at the preconception period. This approach is a pathogenetically substantiated and promising direction for the prevention of some pregnancy complications and improvement of perinatal outcomes. Keywords: pregnancy, deficiency vitamin D, placental dysfunction, preconception period.


2021 ◽  
Author(s):  
Shoko Arita ◽  
Yusuke Shimoda ◽  
Kazunari Toda ◽  
Yoshiki Yamagiwa

2018 ◽  
Author(s):  
Anthony Paul Zanesco ◽  
Ekaterina Denkova ◽  
Scott L. Rogers ◽  
William K. MacNulty ◽  
Amishi P. Jha

Cognitive ability is a key selection criterion for entry into many elite professions. Herein, we investigate whether mindfulness training (MT) can enhance cognitive performance in elite military forces. The cognitive effects of a short-form 8-hour MT program contextualized for military cohorts, referred to as Mindfulness-Based Attention Training (MBAT), were assessed. Servicemembers received either a 2-week (n = 40) or 4-week (n = 36) version of MBAT, or no training (NTC, n = 44). Sustained attention and working memory task performance along with self-reported cognitive failures were assessed at study onset (T1) and 8-weeks later (T2). In contrast to both the NTC and 2-week MT groups, the 4-week MT group significantly improved over time on attention and working memory outcome measures. Among the 4-week more so than the 2-week MBAT participants, working memory performance improvements were correlated with their amount of out-of-class MT practice. In addition to these group-wise effects, all participants receiving MBAT decreased in their self-reported cognitive failures from T1 to T2. Importantly, none of these improvements were related to self-reported task motivation. Together, these results suggest that short-form MT, when delivered over a 4-week delivery schedule, may be an effective cognitive training tool in elite military cohorts.


2018 ◽  
Vol 30 (1-2) ◽  
pp. 32-48
Author(s):  
M. Louail ◽  
S. Prat

The standard ASUDAS scoring system (Arizona State University Dental Anthropology System) is used to assess dental morphological variations in modern humans. It is also frequently used to study, score, and compare morphological variations in fossil hominin taxa and to examine their phylogenetic relationships. However, using ASUDAS in studies of this type is under debate because it is based on modern Homo sapiens populations and does not appear to cover all variations observed in fossil Plio-Pleistocene homi- nins. Our observations and coding of 178 dentals casts of Plio-Pleistocene specimens based on ASUDAS and from the literature have confirmed the need to adapt the standard system to fossil hominins. In this initial study, we propose that the scoring procedures for some morphological characters need to be readjusted, while others could be standardized following the ASUDAS system.


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