Excited State Lifetime Measurement By EEL-CL Coincidence

Author(s):  
C.C. Ahn ◽  
O.L. Krivanek

The lifetime of an excited state can be measured by detecting both the excitation (by EELS) and the de-excitation (by catho- doluminescence), and measuring the delay between the two events. We have adapted this technique for the measurement of lifetimes in an electron microscope.The experimental set-up is shown in Fig. 1. The arrival time and the energy loss of single electrons is monitored by the EELS (Gatan 607), and the arrival time and wavelength of single photons is monitored by the CL spectrometer. Pulses corresponding to the two events are fed to a time-to-amplitude converter (TAC), which outputs a variable height pulse proportional to the delay between the events. If no second (stop) pulse is detected within a preset time interval, the TAC recognizes a “false start”, does not output anything, and starts looking for a “start” pulse again. Since the count rate in the CL channel was typically 10 to 100 times weaker than in the EEL channel, we minimized the false starts by using the CL signal as the start pulse and the EEL signal, suitably delayed, as the stop pulse. This yields a “reversed time” spectrum, but minimizes the dead time of the electronics.

2021 ◽  
Vol 18 (3) ◽  
pp. 271-289
Author(s):  
Evgeniia Bulycheva ◽  
Sergey Yanchenko

Harmonic contributions of utility and customer may feature significant variations due to network switchings and changing operational modes. In order to correctly define the impacts on the grid voltage distortion the frequency dependent impedance characteristic of the studied network should be accurately measured in the real-time mode. This condition can be fulfilled by designing a stimuli generator measuring the grid impedance as a response to injected interference and producing time-frequency plots of harmonic contributions during considered time interval. In this paper a prototype of a stimuli generator based on programmable voltage source inverter is developed and tested. The use of ternary pulse sequence allows fast wide-band impedance measurements that meet the requirements of real-time assessment of harmonic contributions. The accuracy of respective analysis involving impedance determination and calculation of harmonic contributions is validated experimentally using reference characteristics of laboratory test set-up with varying grid impedance.


Author(s):  
Masood Dehghani

Introduction: The only option for treatment of end stage liver diseases is liver transplantation. Afzalipour Hospital in Kerman, Iran is the third largest liver transplantation center in Iran. In this study, the outcomes of this center have been studied during the past 5 years. Methods: In this cross-sectional study, the pre and post transplantation’s clinical, demographic and outcome data of all patients who received liver transplant at Afzalipour Hospital during the past 5 years have been collected and reviewed. SPSS software ver. 16 was used to analyze the data. Results: Forty-three patients have received liver transplantation during this time interval. The 3-year survival rate of patients was 77%. The most common cause of death was primary nonfunction graft after transplantation. The most common complication was acute rejection (15%), all of which were successfully treated with corticosteroids. Conclusion:  Due to increment of cases of acute and chronic liver failure in the community and since the final treatment of these cases is liver transplantation, so there is need to develop liver transplant centers in the future. Quantitative and qualitative study of the activity of centers based liver transplant in Iran is necessary to set up successful centers.


2020 ◽  
Vol 1 (1) ◽  
pp. 1-17
Author(s):  
Kyosuke Futami ◽  
Tsutomu Terada ◽  
Masahiko Tsukamoto

Although it is socially and ethically important not to be late for a specified arrival time, late arrivals sometimes happen to people using public transportation. Although many methods aim to smooth a user's movement by providing useful information, there are few approaches to prevent late arrivals due to psychological factors. In this research, to make a user's arrival time earlier and thus prevent late arrival, we propose a method that manipulates time allowance by presenting information based on a psychological and cognitive tendency. We apply this method to a vehicle timetable system for the purpose of preventing public transit users from arriving after a target vehicle's departure time. Our proposed timetable system manipulates the time intervals between a user's target vehicle and other vehicles by introducing fictional elements such as hidden vehicles and inserted fictional vehicles. This method uses the relationship between the time allowance and the departure time interval, and it can make a user desire and accept arriving at a station earlier. We implemented a prototype system and conducted four experiments. The evaluation results confirmed that our proposed method is effective for changing a user's time allowance and actual arrival time.


2012 ◽  
Vol 32 (4) ◽  
pp. 0403001 ◽  
Author(s):  
刘立生 Liu Lisheng ◽  
张合勇 Zhang Heyong ◽  
赵帅 Zhao Shuai ◽  
郭劲 Guo Jin

2018 ◽  
Vol 12 (2) ◽  
pp. 1-22
Author(s):  
Joel De Lara

In this paper, I contend that the standard interpretation of the Republic, according to which “the city of pigs” (CP) is an entirely deficient precursor to the one ideally just state, Kallipolis, is untenable. In the vital respect of unity, which for Plato is the defining condition of virtue in the soul and the city, CP is equally if not more just than Kallipolis. In part 1, I outline CP in terms of what I contend are the three organizing principles that secure its unity (“trade specialization”; “right size”; and “modesty”), before proceeding to defend this unity from some typical criticisms. The aim is to show that CP is unified and hence just, which allows us to make sense of why Socrates describes it as “complete” (telea), “true” (alêthinê), and “healthy” (hugiês), despite Glaucon’s protestations. To do so, I will have to first argue against objections from those who interpret CP as a suggestio falsi, or an exercise in playful irony, sketched only to establish the need for Kallipolis. In part 2, I then proceed to show that although Kallipolis is in certain respects superior to CP, it suffers from structural disunity relating to its heretofore unnoticed or downplayed geographical and social scissions—scissions that are requisite and unavoidable for its very organization. As such, Socrates tacitly suggests, I contend, that these scissions mark a disunity that results from reneging CP’s third organizing principle: the “modesty” principle. When Socrates, on his interlocutors’ demands, expands CP by allowing in items and conditions of luxury that provoke pleonexia (greed or covetousness) thus giving birth to the “feverish city,” he leads us to see the necessity of a kind of set-up in Kallipolis with a socially and geographically disparate class of guardians that is saturated by disunity. The overall argument of this paper is that Socrates takes us on a dialectical journey, leading us to see that unity and hence justice in each city depends upon each citizen doing her job and no more than her job (i.e., the principle of trade specialization) (433A-B). Both CP and Kallipolis are sketched for this heuristic purpose—to allow us to see this vision of justice. Socrates’ point in taking us on the dialectical journey, I contend, is to enable us to realize not just what justice is but what inhibits or threatens justice—namely, luxury, or more precisely wealth. CP is not a good model to allow us to see this, but this does not render it a suggestio falsi or an unrealistic false start. Indeed, on my reading, Socrates is not only serious when he dubs the city of pigs true and healthy, but we have to take these pronouncements seriously in order to properly accompany him on the journey and properly see his vision of political justice and injustice.


Algorithms ◽  
2019 ◽  
Vol 12 (10) ◽  
pp. 211 ◽  
Author(s):  
Pierluigi Crescenzi ◽  
Clémence Magnien ◽  
Andrea Marino

Temporal networks are graphs in which edges have temporal labels, specifying their starting times and their traversal times. Several notions of distances between two nodes in a temporal network can be analyzed, by referring, for example, to the earliest arrival time or to the latest starting time of a temporal path connecting the two nodes. In this paper, we mostly refer to the notion of temporal reachability by using the earliest arrival time. In particular, we first show how the sketch approach, which has already been used in the case of classical graphs, can be applied to the case of temporal networks in order to approximately compute the sizes of the temporal cones of a temporal network. By making use of this approach, we subsequently show how we can approximate the temporal neighborhood function (that is, the number of pairs of nodes reachable from one another in a given time interval) of large temporal networks in a few seconds. Finally, we apply our algorithm in order to analyze and compare the behavior of 25 public transportation temporal networks. Our results can be easily adapted to the case in which we want to refer to the notion of distance based on the latest starting time.


2017 ◽  
Vol 29 (1) ◽  
pp. 67-75 ◽  
Author(s):  
Jiahui Liu ◽  
Peiqun Lin ◽  
Jing(Peter) Jin

The aim of this paper is to develop a cooperative control model for improving the operational efficiency of Bus Rapid Transit (BRT) vehicles. The model takes advantage of the emerging connected vehicle technology. A connected vehicle centre is established to assign a specific reservation time interval and transmit the corresponding dynamic speed guidance to each BRT vehicle. Furthermore, a set of constraints have been set up to avoid bus queuing and waiting phenomena in downstream BRT stations. Therefore, many BRT vehicles are strategically guided to form a platoon, which can pass through an intersection with no impedance. An actual signalized intersection along the Guangzhou BRT corridor is employed to verify and assess the cooperative control model in various traffic conditions. The simulation-based evaluation results demonstrate that the proposed approach can reduce delays, decrease the number of stops, and improve the sustainability of the BRT vehicles.


Author(s):  
Joyce F. Akpan ◽  
Godwin M. Ubi ◽  
R. N. Njoku

Experiment was set up in May to September, 2019 to evaluate the impact of algal bio-fertilizers on fruit lignification time interval, total genomic DNA contents, growth attributes as well as the yield components of three okra (Abelmoschus esculentus) (NHAE-47-4, NHAe-54-4 and Agwu early) genotypes sourced from NIHORT, Ibadan, Oyo State, Nigeria. The bio-fertilizers used for the study were a combination of cow dung + algae, poultry droppings + algae, Green Compost + algae and only soil as control. The test crops were sown into 50 x 30 x 25 cm3 perforated plastic buckets containing 5 kg of sterilized sandy loam soil and applied with the bio-fertilizers at 500 g each. The bio-fertilizers were prepared by using a combination of algae and organic manures. The experiment was a 3 x 4 experiment set up in completely randomized design (CRD) with 3 replications. Factor one was the Okra (Abelmoschus esculentus) genotypes with three levels (NHAe-47-4; NHAe-54-4 and Agwu early) while factor two was the different bio-fertilizers used with four levels (Cow dung + Algae; Polutry droopings + Algae; Green compost manure + Algae and soil as control). This gave a total treatment combination of 12 which was replicated thrice to give a total of 36 experimental units. Data for yield components were collected at maturity for days to flower initiation, number of seeds per pod, number of pods per plants and fresh fruit weight. Data generated from the study were collated and subjected to statistical analysis using the analysis of variance (ANOVA) procedures and significant treatment means were further separated using the Fishers’ least significance difference test at 5 percent probability level. The results shows that genomic DNA contents varies from 134.100 ng/µl in Agwu early in control plot to 175.600 ng/µl in NHAe -54-4 treated with Poultry droppings +Algae. Fruit lignification time interval  was significantly (p <0.05) influenced by the bio-fertilizers and varied between 3 days 6 minutes in Agwu early in the control plots to 8 days and 23 hours in NHAe 47-4 treated with Poultry dropping + Alage. Plant height varied (p <0.05) significantly and ranged from 14.13 cm in Agwu early in control plot to 44.34 cm in NHAe-47-4 treated with Poultry droppings + Algae while number of fruits per plant also varied        (p <0.05) significantly and ranged between 12.57 fruits per plant in Agwu early in control plots to 24.30 fruits per plant in NHAe-47-4 treated with Poultry droppings + Algae. Hence, the study advocated for the use of poultry droppings + Algal bio-fertilizer in prolonging the fruit lignification time in okra for planned harvesting, increased income and mechanization of okra harvesting.


2020 ◽  
Vol 9 (1) ◽  
pp. 44-53
Author(s):  
Muhammad Ikhwan Kosasih ◽  
Nugrahaeni Firdausi ◽  
Erwin Yektiningsih ◽  
Zauhani Kusnul

Stroke is an important health problem. The speed with which a stroke sufferer gets the right treatment cause a big influence on stroke management. This study analyze the influence of various factors in the family on the arrival time of stroke patients in the emergency department of the Kediri district hospital. The study was conducted during May-July 2019 and found stroke patients as many as 88. The result show that educational factors have a significant relationship with the level of knowledge, and  the family age, job, people who knew the stroke and decision-makers in the family have a significant relationship with the time interval between the stroke attack with the arrival of patients in the emergency room. From this study, it can be concluded that family factors play an important role in the time interval between a stroke and the arrival of a patient on IGD to get proper treatment.


2021 ◽  
Author(s):  
Félix Geoffroy ◽  
Arne Traulsen ◽  
Hildegard Uecker

When vaccine supply is limited but population immunisation urgent, the allocation of the available doses needs to be carefully considered. One aspect of dose allocation is the time interval between the primer and the booster injections in two-dose vaccines. By stretching this interval, more individuals can be vaccinated with the first dose more quickly. Even if the level of immunity of these 'half-vaccinated' individuals is lower than that of those who have received both shots, delaying the second injection can be beneficial in reducing case numbers, provided a single dose is sufficiently effective. On the other hand, there has been concern that intermediate levels of immunity in partially vaccinated individuals may favour the evolution of vaccine escape mutants. In that case, a large fraction of half-vaccinated individuals would pose a risk – but only if they encounter the virus. This raises the question whether there is a conflict between reducing the burden and the risk of vaccine escape evolution or not. We develop a minimal model to assess the population-level effects of the timing of the booster dose. We set up an SIR-type model, in which more and more individuals become vaccinated with a two-dose vaccine over the course of a pandemic. As expected, there is no trade-off when vaccine escape evolves at equal probabilities in unvaccinated and half-vaccinated patients. If vaccine escape evolves more easily in half-vaccinated patients, the presence or absence of a trade-off depends on the reductions in susceptibility and transmissibility elicited by the primer dose.


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