Academic literature on the topic 'Moment till impact'

Since first cluster of unknown pneumonia from China reported in December 2019 to World Health Organization, more than 10.5 million new cases and more than 0.513 million deaths have been reported till June 30, 2020 in six months’ time. World got to know lot of facts about COVID-19 within short period of six months and success stories too concerning its containment. The situation has constantly been unfolding every moment educating people regarding public health and clinical aspects of the infection and disease and its impact on countries and communities. But still lot of information and evidences are required with regard to pharmacological interventions including effective drugs and efficacious vaccine to mitigate the impact of COVID-19 pandemic at all levels. It seems that we have to live with COVID-19 months-years as the virus is going to stay for longer period of time. The option is to continue practice of effective non-pharmacological interventions as to minimize spread of COVID-19 and ensure adequate provision of PPE to healthcare workforce and testing of health-care workers (HCWs) as to alleviate the anxiety of HCW and lessen their depletion by unnecessary quarantine thereby protect their health and reduce in hospital transmission.

Experimental Research of the Overvoltage in the Insulated Neutral Network The isolated neutral network isolation resistance is often affected by the lightning discharge surge to the line cables or towers. Several overvoltage waves are maid at the moment of the lightning discharge surge. It is dangerous for the devices because at the very short time period the isolation of the device is affected by the surge impact twice or even more. The analysis of the experimentally registered lightning discharge induced overvoltage transients effect from the lightning influence to the power line till the power line disconnection were analyzed in this work. Estimation of the overvoltage characteristics to the isolation resistance was made.

In different periods of modern history, the development of the state has always been based on certain models of interaction between the government and business, which were the most preferred ones at a particular historical moment. The article analyzes the essence of the concepts of «interaction between the government and business structures», «mechanisms of interaction», the authors also show that when determining the feasibility of interaction between the government and business in various forms and spheres, it is necessary to take into account the impact of such interaction, the characteristics of the existing models of interaction between the executive authorities and the business community. The article evaluates the potential of interaction between the government and business in terms of economic assessment of the feasibility of state regulation measures, it shows the features of quantitative assessment of the regulatory impact of the projects adopted by regulatory legal acts in the Khabarovsk territory, consistently included in the TOP 6 regions-the leaders of the Russian Federation to improve the interaction between the government and business in the period from 2014 till 2017.

TRIP (transformation induced plasticity) steels are low and medium-carbon steels containing soft ferritic groundmass responsible for low yield point and phases of hard particles such as martensite and/or bainite, which ensure high values of tensile strength. The most important content in structure of TRIP steel is occupied by a non-transformation retained austenite. The advantageous properties of these steels are obtained as a result of martensite transformation generated by plastic deformation process. The retained austenite induces increase of steel plasticity till the moment when by the impact of plastic deformation will undergo deformation in martensite, which results in the increase of steel mechanical properties. The speed of transformation of retained austenite in martensite is highly dependent on strain magnitude and strain rate magnitude. The paper presents the research of strain rate and intensity on retained austenite content ensuring TRIP effect in structure of low carbon steel (0.29%C). Finite element analysis for different strain rate and strain degree values in upsetting test was performed by means of software FORGE 3D. The practical analysis obtained from simulation results was realized by using metallurgical processes simulator Gleeble 3800.

Abstract World history can be arranged into three major regional divergences: the 'Greatest Divergence' starting at the end of the last Ice Age (ca. 15,000 years ago) and isolating the Old and the New Worlds from one another till 1500; the 'Great Divergence' bifurcating the paths of Europe and Afro-Asia since 1500; and the 'American Divergence' which divided the fortunes of New World societies from 1500 onwards. Accordingly, all world regions have confronted two divergences: one disassociating the fates of the Old and New Worlds, and the other within either the Old or the New World. Latin America is in the uneasy position that in both divergences it ended up on the 'losing side.' As a result, a contentious historiography of Latin America evolved from the very moment that it was incorporated into the wider world. Three basic attitudes toward the place of Latin America in global history have since emerged and developed: admiration for the major impact that the emergence on Latin America on the world scene imprinted on global history; hostility and disdain over Latin America since it entered the world scene; direct rejection of and head on confrontation in reaction the former. This paper examines each of these three attitudes in five periods: the 'long sixteenth century' (1492-1650); the 'age of crisis' (1650-1780); 'the long nineteenth century' (1780-1914); 'the short twentieth century' (1914-1991); and 'contemporary globalization' (1991 onwards).

Recent years have witnessed a whole range of changes in the global economic system; the changes have largely resulted from crisis situations in global markets. Air transport is an element of the system that is very sensitive to any kinds of changes. Due to a difficult financial situation the sector is relatively quickly affected. The corporate representatives and individuals in situation of financial crisis can easily resign from air transportation, especially for short distance travel. The main purpose of the paper is to present changes in passenger’s air transport quantity in the largest airports of the world with respect to the selected air carriers. The first part of the article presents the size of passenger’s air transport in the airports with the highest number of passengers (Atlanta Hartsfield-Jackson, London Heathrow, Frankfurt International) in years 2007−2010, i.e. since the moment preceding the global trend of decrease in air transportation till now (in accordance with the current availability of statistic data). Next, the changes in passenger’s air transportation quantity for the selected air carriers operating in various parts of the world have been analyzed with respect to a comparable period of time. In the last part of the paper the authors tried to present the examples of the impact of crisis on particular air carriers as well as to discuss the attempts undertaken to restore the passenger’s transportation rates to the level preceding the crisis.

Theoretically, stock dividends have no impact on financial position of the announcing company as net worth and total assets remain the same, though empirical evidence across the globe shows that markets react to stock dividend announcements. The present study analyses the market reaction pertaining to stock dividend decisions in the Indian context. Market reaction has been captured in terms of impact on returns, liquidity, and risk. The sample includes 51 ‘pure’ stock dividend announcements from January 1, 2002 to June 30, 2010. The study finds that the announcement of stock dividends induces an increase in the wealth of the shareholders in India. A consistent pattern of positive average abnormal returns during the pre-announcement window till the announcement day and a pattern of negative average abnormal returns during the post-announcement window have been observed. On cumulating these results, the shareholders of the companies that issued stock dividends gain significant returns. The justification for such results seems to be that the information about the stock dividends announcement reaches the investors prior to the decision date as it is manda-tory for the issuing company to inform the exchange (where it is listed) about the date of the board meeting. It has been observed that the companies usually inform the exchange seven days prior to the day of the board meeting. In most of the cases, the companies provide the agenda item information along with the board meeting date to the exchange. In such a situation, the moment this information about the agenda item is given to the exchange, this becomes public information and investors start reacting to it. The cumulative average abnormal return values over various size event windows depict that an investor can earn substantial returns if he purchases the shares on the day the news of board meeting (to announce stock dividends) comes to the market and sells them one day after the announcement day. The investor can also gain if the shares are purchased one day prior to the announcement day and are sold one day after the announcement day. The trading quantity reduces significantly immediately after these decisions are announced. On a short-term basis, the investors seem to perceive that the announcement of stock dividends provides signals about the firm's bright future prospects. This leads to a decline in trading quantity as investors, who own the shares at the time of announcement, prefer to hold the shares expecting an increase in their wealth in future. In the long-run, a marginally positive impact has been observed. The announcement of stock dividends reduces variability of returns in the short-run as well as in the long run, lending price stability to the stocks of the announcing companies.

The intermetallic compound Fe 2 AlTi (alternatively Fe 2 TiAl) is an important phase in the ternary Fe-Al-Ti phase diagram. Previous theoretical studies showed a large discrepancy of approximately an order of magnitude between the ab initio computed magnetic moments and the experimentally measured ones. To unravel the source of this discrepancy, we analyze how various mechanisms present in realistic materials such as residual strain effects or deviations from stoichiometry affect magnetism. Since in spin-unconstrained calculations the system always evolves to the spin configuration which represents a local or global minimum in the total energy surface, finite temperature spin effects are not well described. We therefore turn the investigation around and use constrained spin calculations, fixing the global magnetic moment. This approach provides direct insight into local and global energy minima (reflecting metastable and stable spin phases) as well as the curvature of the energy surface, which correlates with the magnetic entropy and thus the magnetic configuration space accessible at finite temperatures. Based on this approach, we show that deviations from stoichiometry have a huge impact on the local magnetic moment and can explain the experimentally observed low magnetic moments.

In standard solutions, reactions of the supports and bending moments in bearing shafts are calculated without taking into consideration the elasticity of the bearings themselves. They are treated as perfectly stiff supports of articulate character. Whereas, in reality, the majority of bearings do not fulfil conditions of being classified as joints, because the angular tilt of inner bearing ring in relation to the outer one causes inner elastic deformations in elements of bearings and the resulting reaction moments. These moments have an impact on reactions of bearings. The aim of the research is to determine how shaft loading influences the value of preload by using the criterion of the durability of the bearing and taking into consideration the elasticity of bearings.

Analysis using human body models has been performed to reduce the impact of accidents; however, no analysis has shown a relationship between lumbar and pelvic/spine angle and seat belts in reducing human damage from accidents. Lumbar and pelvic/spine angles were measured in 75 individuals and the measurements were used to create three different angles for the Total Human Model for Safety model. In the present study, we focused on lumber lordosis (LL) and pelvic angle (PA). A normal distribution and histogram were used for analysis of PA (01, 10, and 50). The Total Human Model for Safety, including LL and PA, was corrected using finite element software. Simulations were conducted under the conditions of the Japan New Car Assessment Programme (JNCAP) 56 kph full lap frontal impact. Using the results of the FEM, the amount of lap-belt cranial sliding-up, anterior movement of the pelvis, posterior tilt of the pelvis, head injury criterion (HIC), second cervical vertebrae (C2) compressive load, C2 moment, chest deflectiou (upper, middle, and lower), left and right femur load, and shoulder belt force were measured. The lap-belt cranial sliding-up was 1.91 and 2.37 for PA10 and PA01, respectively, compared to PA50; the anterior movement of the pelvis was 1.08 and 1.12 for PA10 and PA01, respectively; and the posterior tilt of the pelvis was 1.1 and 1.18 for PA10 and PA01, respectively. HIC was 1.13 for PA10 and 1.58 for PA01; there was no difference in C2 compressive load by PA, but C2 moment increased to 1.59 for PA10 and 2.72 for PA01. It was found that as LL increases and the PA decreases, the seat belt becomes likely to catch the iliac bone, making it harder to cause injury. This study could help to reconsider the safe seat and seatbelt position in the future.

This thesis is concerned with the accuracy of our estimation of time to make contact with an approaching object as measured by the “Prediction Motion” (PM) technique. The PM task has commonly been used to measure the ability to judge time to contact (TTC). In a PM task, the observer's view of the target is occluded for some period leading up to the moment of impact. The length of the occlusion period is varied and the observer signals the moment of impact by pressing a response key. The interval separating the moment of occlusion and the response is interpreted as the observer's estimate of TTC made at the moment of occlusion. This technique commonly produces large variability and systematic underestimation. The possibility that this reflects genuine perceptual errors has been discounted by most writers, since this seems inconsistent with the accuracy of interceptive actions in real life. Instead, the poor performance in the PM task has been attributed to problems with the PM technique. Several hypotheses have been proposed to explain the poor PM performance. The motion extrapolation hypothesis asserts that some form of mental representation of the occluded part of the trajectory is used to time the PM response; the errors in PM performance are attributed to errors in reconstructing the target motion. The clocking hypothesis assumes that the TTC is accurately perceived at the moment of occlusion and that errors arise in delaying the response for the required period. The fear-of-collision hypothesis proposes that the underestimation seen in the PM tasks reflects a precautionary tendency to anticipate the estimated moment of contact. This thesis explores the causes of the errors in PM measurements. Experiments 1 and 2 assessed the PM performance using a range of motion scenarios involving various patterns of movement of the target, the observer, or both. The possible contribution of clocking errors to the PM performance was assessed by a novel procedure designed to measure errors in the wait-and-respond component of the PM procedure. In both experiments, this procedure yielded a pattern of systematic underestimation and high variability similar to that in the TTC estimation task. Experiment 1 found a small effect of motion scenario on TTC estimation. However, this was not evident in Experiment 2. The collision event simulated in Experiment 2 did not involve a solid collision. The target was simply a rectangular frame marked on a tunnel wall. At the moment of “contact”, the observers passed “through” the target without collision. However, there was still systematic underestimation of TTC and there was little difference between the estimates obtained in Experiments 1 and 2. Overall, the results of Experiments 1 and 2 were seen as inconsistent with either the motion extrapolation hypothesis or the fear-of-collision hypothesis. It was concluded that observers extracted an estimate of the TTC based on optic TTC information at a point prior to the moment of collision, and used a timing process to count down to the moment of response. The PM errors were attributed to failure in this timing process. The results of these experiments were seen as implying an accurate perception of TTC. It was considered possible that in Experiments 1 and 2 observers based their TTC judgements on either the retinal size or the expansion rate of the target rather than TTC. Experiments 3 and 4 therefore investigated estimation of TTC using a range of simulated target velocities and sizes. TTC estimates were unaffected by the resulting variation in expansion rate and size, indicating that TTC, rather than retinal size or image expansion rate per se, was used to time the observers' response. The accurate TTC estimation found in Experiments 1-4 indicates that the TTC processing is very robust across a range of stimulus conditions. Experiment 5 further explored this robustness by requiring estimation of TTC with an approaching target which rotated in the frontoparallel plane. It was shown that moderate but not fast rates of target rotation induced an overestimation of TTC. However, observers were able to discriminate between TTCs for all rates of rotation. This shows that the extraction of TTC information is sensitive to perturbation of the local motion of the target border, but it implies that, in spite of these perturbations, the mechanism is flexible enough to pick up the optic TTC information provided by the looming of the retinal motion envelop of the rotating stimulus.

Till this moment she had never seen or heard from d’Urberville since her departure from Trantridge. The rencounter came at a heavy moment, one of all moments calculated to permit its impact with the least emotional shock. But such was unreasoning memory that, though he...

No aspect of human life has remained untouched by information and communication technologies (ICT) at present. Various forms of media like radio, computers, televisions, computers, etc. keep on surrounding us right from the moment we wake up in the morning till we go to bed at night. The electronic media, which have become an inseparable part of our daily lives, fall under the umbrella of a single entity known as ICT. As the society has moved one step ahead from being information society to acquiring the status of knowledge society, the knowledge and use of ICT tools has become even more important. ICT has a deep impact on every sphere of human life and education is no exception. Use of information communication technologies has promoted drastic changes in work environment, transformed the ways of handling and exchanging information, and has an everlasting impact on teaching-learning pedagogy. This chapter presents the role of ICT transforming the teaching and learning environments. The limitation of ICT and the challenges in implementation have also been discussed.

The risk assessment for population’s exposures to low doses and low dose-rates of ionizing radiation is still subject to clear uncertainties. The issue has outstanding societal importance in relation to radiologic occupational safety, medical applications of radiation, effects of the natural background radioactivity and the future of nuclear power, due to its particular influence on the public acceptance of this form of energy. This review article analyzes, in a critical, historical and bibliographical manner, the worldwide accepted hypothesis of linearity without a threshold dose (LNT model). As well known, it rejects, from its first proposal in 1946 by American geneticist and Nobel laureate Hermann J. Muller, the concept of zero-risk for exposures to any dose level of ionizing radiation. The starting point is the dose-effects relationship provided by this model and related risk’s excess graphic curve. The biological and physical motivations for the linearity assumption are argued and challenged by the explanation of human body’s natural defense mechanisms and its repair capacity of the radiation damage. Furthermore, the historical and political truthfulness of the LNT model is also contested by the review of a recent investigation by Prof. Edward Calabrese, regarding the lack of scientific sources behind Muller’s Nobel Prize Lecture. Calabrese’s inquiry demonstrates that Muller, at the moment of his declaration on LNT model’s validity, had experimental proofs contradicting his conclusions about the unacceptability of a threshold dose. This finding is of historical importance since Muller’s Nobel Lecture is a turning point in the acceptance of the linearity model in risk assessment by the major regulatory agencies till today. Finally, the results of many epidemiological and statistical studies are shown specifically. They give further evidences concerning the inapplicability of the LNT model and its overestimation of the risk for various cases of exposures to low doses of ionizing radiation in different fields. By that, hormesis model is also discussed, with its assumption of possible benefits for the organism following low dose exposures: a dose-response model characterized by low-dose stimulation and high-dose inhibition, which has been frequently observed in the aforementioned studies. The argumentations and the experimental evidences provided here challenge the validity of the LNT model. We contest the fact that its establishment is principally based on a cautionary philosophy on nuclear public safety, rather than on actual scientific comprehension of the phenomenon. As such, it implies an exaggerated conception of the radiological hazard. In particular, this article calls attention to the need for a deeper understanding of the biological impact of low doses of ionizing radiation and the development of further specific and exhaustive researches.

Wave energy is the most promising natural energy resource that is gaining momentum in the recent years. Successful attempts are made by several researchers to harness wave energy by heave, surge and sway motion of the devices; however no successful commercial model is launched till date leaving this domain as a research potential. Among the proposed technologies, point absorbers are found to be commercially viable to a greater extent primarily due to its simplicity. The present study discusses a new mechanical wave energy converter (MWEC) using point absorber as a wave energy capturing device. Heave motion of a floating buoy due to incident wave field is harnessed to produce power. The conversion takes place in four different stages namely: i) motion of a gear rack, attached to floating buoy results in heave motion; ii) this vertical reciprocating motion is converted to oscillatory rotation of a shaft by a rack and pinion arrangement; iii) alternative rotary motion is converted in to continuous unidirectional rotation using a unidirectional chain assembly; and iv) unidirectional rotation is converted in to other usable energy form. MWEC employs numerous operating advantages over other systems such as: (i) the rack and pinion gear arrangement enabling the buoy to float in line to the changing water levels automatically. (ii) use of RPM multiplier enables rotation of generator shaft at high RPM even for small displacement of float; (iii) the free wheel sprockets of unidirectional chain assembly enable the gear rack to produce a positive upward stroke and a positive downward stroke for every passing wave impact. Further, rpm multiplier shall be easily adjusted to rotate the generator at desired rpm while the whole operation shall be shut down on emergency. The paper presents a detailed analysis of the mechanical system to arrive at the efficiency of the developed MWEC. Based on the studies conducted, it is seen that the overall efficiency of the MWEC is about 19% while maintaining maximum possible efficiency of the mechanical systems involved in the design.