scholarly journals The formation of a blast wave by a very intense explosion. - II. The atomic explosion of 1945

Photographs by J. E. Mack of the first atomic explosion in New Mexico were measured, and the radius, R , of the luminous globe or ‘ball of fire’ which spread out from the centre was determined for a large range of values of t , the time measured from the start of the explosion. The relationship predicted in part I, namely, that R* would be proportional to t , is surprisingly accurately verified over a range from R = 20 to 185 m. The value of R" t-1 so found was used in conjunction with the formulae of part I to estimate the energy E which was generated in the explosion. The amount of this estimate depends on what value is assumed for y , the ratio of the specific heats of air. Two estimates are given in terms of the number of tons of the chemical explosive T.N.T. which would release the same energy. The first is probably the more accurate and is 16,800 tons. The second, which is 23,700 tons, probably overestimates the energy, but is included to show the amount of error which might be expected if the effect of radiation were neglected and that of high temperature on the specific heat of air were taken into account. Reasons are given for believing that these two effects neutralize one another. After the explosion a hemispherical volume of very hot gas is left behind and Mack’s photographs were used to measure the velocity of rise of the glowing centre of the heated volume. This velocity was found to be 35 m./sec. Until the hot air suffers turbulent mixing with the surrounding cold air it may be expected to rise like a large bubble in water. The radius of the ‘equivalent bubble’ is calculated and found to be 293 m. The vertical velocity of a bubble of this radius is 2/3 √(g 29300) or 35.7 m./sec. The agreement with the measured value, 35 m./sec., is better than the nature of the measurements permits one to expect.

2019 ◽  
Vol 8 ◽  
pp. 54-56
Author(s):  
Ashmita Dahal Chhetri

Advertisements have been used for many years to influence the buying behaviors of the consumers. Advertisements are helpful in creating the awareness and perception among the customers of a product. This particular research was conducted on the 100 young male and female who use different brands of product to check the influence of advertisement on their buying behavior while creating the awareness and building the perceptions. Correlation, regression and other statistical tools were used to identify the relationship between these variables. The results revealed that the relationship between media and consumer behavior is positive. The adve1tising impact on sales and there is positive and high degree relationship between advertising and consumer behavior. The impact on advertising of a product of electronic media is better than non-electronic media.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2972
Author(s):  
Zhili Zuo ◽  
Jinhua Cheng ◽  
Haixiang Guo ◽  
Yonglin Li

Based on resource carrying capacity, this study used the revised theory of relative resource carrying capacity (RRCC) and introduced an innovative concept of relative fossil energy carrying capacity (RFECC), which evaluates the degree of fossil energy sustainability based on the relationship between economy, population, and environment. This study took China and the United States as the study objects, took the whole country as the reference area, and calculated the RFECC of population, economic, and environmental resources from 2000 to 2018. Therefore, based on the comparative analysis, the following conclusions were drawn: (i) there is a big difference in the RFECC between China and the United States, which is manifested in the inverted U-shaped trend in China and the U-shaped trend in the United States; (ii) the relative fossil energy carrying states in China and the United States are different, mainly reflected in the economy and environment; (iii) the gap in RFECC between China and the United States has gradually widened; in general, China’s economic RFECC is better than that of the United States, while environmental RFECC and population RFECC in the United States is better than that of China; and (iv) coal and oil should be used as a breakthrough point for the sustainable fossil energy and sustainable development for China and the United States, respectively.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Martin Saveski ◽  
Edmond Awad ◽  
Iyad Rahwan ◽  
Manuel Cebrian

AbstractAs groups are increasingly taking over individual experts in many tasks, it is ever more important to understand the determinants of group success. In this paper, we study the patterns of group success in Escape The Room, a physical adventure game in which a group is tasked with escaping a maze by collectively solving a series of puzzles. We investigate (1) the characteristics of successful groups, and (2) how accurately humans and machines can spot them from a group photo. The relationship between these two questions is based on the hypothesis that the characteristics of successful groups are encoded by features that can be spotted in their photo. We analyze >43K group photos (one photo per group) taken after groups have completed the game—from which all explicit performance-signaling information has been removed. First, we find that groups that are larger, older and more gender but less age diverse are significantly more likely to escape. Second, we compare humans and off-the-shelf machine learning algorithms at predicting whether a group escaped or not based on the completion photo. We find that individual guesses by humans achieve 58.3% accuracy, better than random, but worse than machines which display 71.6% accuracy. When humans are trained to guess by observing only four labeled photos, their accuracy increases to 64%. However, training humans on more labeled examples (eight or twelve) leads to a slight, but statistically insignificant improvement in accuracy (67.4%). Humans in the best training condition perform on par with two, but worse than three out of the five machine learning algorithms we evaluated. Our work illustrates the potentials and the limitations of machine learning systems in evaluating group performance and identifying success factors based on sparse visual cues.


2020 ◽  
pp. 088626051989734 ◽  
Author(s):  
Quanquan Wang ◽  
Xia Liu

Peer victimization is a serious issue among school-aged children. Chinese left-behind children tend to experience peer victimization and associated nonsuicidal self-injury (NSSI) behavior. However, the possible improvement of subjective socioeconomic status (SES) based on increased family income may serve to buffer the relationship between peer victimization and NSSI, and this buffering effect may differ by level of social support. Thus, the current study aimed to examine the moderating effect of subjective SES on the relationship between peer victimization and NSSI by the level of social support among Chinese left-behind children. A total of 431 left-behind children and 447 non-left-behind children (comparison group) completed self-report scales measuring peer victimization, NSSI, subjective SES, and social support. Results showed that peer victimization was positively related to NSSI among left-behind children, but not among non-left-behind children. Moreover, for left-behind children with low levels of social support, high subjective SES intensified the association between peer victimization and NSSI; peer victimization was positively associated with NSSI among left-behind children who reported high subjective SES, but not among those with low subjective SES. However, high levels of social support seemed to protect the left-behind children with high subjective SES who experienced peer victimization from NSSI. For non-left-behind children with both parents present, high subjective SES played a protective role in the association between peer victimization and NSSI, regardless of the levels of social support they enjoyed. These findings contribute to an understanding of subjective SES as a moderating mechanism in the association between peer victimization and NSSI among left-behind children. Social support proved central to the protective role of subjective SES. Intervention programs to enhance social support can help to strengthen the protective effect of subjective SES on NSSI among left-behind children who experience peer victimization.


1963 ◽  
Vol 61 (1) ◽  
pp. 33-43 ◽  
Author(s):  
G. W. Arnold ◽  
M. L. Dudzinski

Data from thirty-five digestibility trials with sheep in metabolism cages were used to investigate statistically the relationships between organic matter intake (I), faecal organic matter output (F), and the nitrogen concentration in faecal organic matter (N).The data fell easily into groups due to botanical or seasonal differences in the feed. These groups of data were homogeneous and provided highly significant linear equations of the forms I = bF + cFN and I = a + cFN. When compared these groups of data sometimes showed differences in slope, position or both. A quadratic expressionI = bF + cFN + dFN2was found to accommodate a majority of the data but to be less precise than I = a + cFN.A further expression incorporating N as an independent variable was also examined,I = a + cFN2 + eN.This expression, although far from being universally adequate, proved to be generally better than existing formulae. When applied to the data of Greenhalgh et. al. (1960), it substantially reduced heterogeneity between data for spring and data for summer pastures.Causes of variation in the relationship between organic-matter intake and nitrogen in faeces, and some of the hazards of extrapolation from empirical regression relations, are discussed.


Genus ◽  
2021 ◽  
Vol 77 (1) ◽  
Author(s):  
Andrea Priulla ◽  
Nicoletta D’Angelo ◽  
Massimo Attanasio

AbstractThis paper investigates gender differences in university performances in Science, Technology, Engineering and Mathematics (STEM) courses in Italy, proposing a novel application through the segmented regression models. The analysis concerns freshmen students enrolled at a 3-year STEM degree in Italian universities in the last decade, with a focus on the relationship between the number of university credits earned during the first year (a good predictor of the regularity of the career) and the probability of getting the bachelor degree within 4 years. Data is provided by the Italian Ministry of University and Research (MIUR). Our analysis confirms that first-year performance is strongly correlated to obtaining a degree within 4 years. Furthermore, our findings show that gender differences vary among STEM courses, in accordance with the care-oriented and technical-oriented dichotomy. Males outperform females in mathematics, physics, chemistry and computer science, while females are slightly better than males in biology. In engineering, female performance seems to follow the male stream. Finally, accounting for other important covariates regarding students, we point out the importance of high school background and students’ demographic characteristics.


1977 ◽  
Vol 45 (3_suppl) ◽  
pp. 1076-1078 ◽  
Author(s):  
John E. Bassett ◽  
Edward B. Blanchard ◽  
William F. Gayton ◽  
Kenneth L. Ozmon

To examine the relationship between performance on the Frostig Developmental Test of Visual Perception and birth order, 578 first-graders were tested. Later-born children performed significantly better than did firstborns on specific subtests of the Frostig (Visual-motor Coordination and Figure-ground Perception). There was a significant interaction on Perceptual Constancy which indicated that later-born males performed significantly better than did firstborn males. A secondary finding was a r of .547, a stronger relationship between intelligence level and global perceptual performance than previously reported.


1966 ◽  
Vol 18 (2) ◽  
pp. 645-646 ◽  
Author(s):  
Barbara J. Powell ◽  
M. E. Ogle ◽  
L. K. Martin ◽  
D. K. Kamano

In studying the relationship between level of CS intensity (light) and drug condition (amobarbital sodium) in the acquisition of the conditioned avoidance response of the white rat in a jump-box task, data showed that both variables influenced avoidance performance. Although the over-all performance of drugged Ss was better than that of those given a placebo, primary differences occurred at 50,000 and 800,000 peak candles of CS intensity; performance of Ss under placebo showed a marked decline at 800,000 peak candles.


2011 ◽  
Vol 1 (1) ◽  
pp. 101-114
Author(s):  
Sachin Ghimire

Armed conflict has left behind a legacy of social separation, physical loss of human lives and a population suffering from many kinds of physical and mental morbidities. In the post-conflict context, a lengthy political transition, coterie politics and the absence of a stable government are severely hindering the realisation of people's aspirations. Such hindrances have fostered a deep level of political frustration and promoted a culture of depoliticization. In Rolpa, lack of political commitment has meant people's health has become an overlooked agenda and has forced people to lose hope for change and survive with silent sufferings. Through the lens of a value-critical approach, this paper attempts to explore the relationship between politics of exclusion and its reflection on individual level pain and suffering in Rolpa.


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