Saving fun for a boring future

We discuss how experiences that fill a future waiting period, such as focusing on fun or boring future activities, affect intertemporal choices. We propose that savoring, the positive utility derived from anticipating future pleasant outcomes, is more likely to have an impact on intertemporal choices when the future seems boring than when it seems fun. We provide empirical evidence that people who foresee a busy future full of boring activities are more likely to prefer to delay rewards than people who foresee a future not so busy with boring activities

Target shape effects on monoenergetic GeV proton acceleration

When a circularly polarized laser pulse interacts with a foil target, there are three stages: pre-hole-boring, hole-boring and the light sail acceleration. We study the electron and ion dynamics in the first stage and find the minimum foil thickness requirement for a given laser intensity. Based on this analysis, we propose to use a shaped foil for ion acceleration, whose thickness varies transversely to match the laser intensity. Then, the target evolves into three regions: the acceleration, transparency and deformation regions. In the acceleration region, the target can be uniformly accelerated producing a mono-energetic and spatially collimated ion beam. Detailed numerical simulations are performed to check the feasibility and robustness of this scheme, such as the influence of shape factors and surface roughness. A GeV mono-energetic proton beam is observed in the three dimensional particle-in-cell simulations when a laser pulse with the focus intensity of 1022W=cm2 is used. The energy conversion efficiency of laser pulse to accelerated proton beam is more than 23%. Synchrotron radiation and damping effects are also checked in the interaction.Comment: 11 pages, 9 figure

Hardy's paradox and violation of a state-independent Bell inequality in time

Tests such as Bell's inequality and Hardy's paradox show that joint probabilities and correlations between distant particles in quantum mechanics are inconsistent with local realistic theories. Here we experimentally demonstrate these concepts in the time domain, using a photonic entangling gate to perform nondestructive measurements on a single photon at different times. We show that Hardy's paradox is much stronger in time and demonstrate the violation of a temporal Bell inequality independent of the quantum state, including for fully mixed states.Comment: Published Version, 4 pages, 3 figures. New, more boring titl

Laser opacity in underdense preplasma of solid targets due to quantum electrodynamics effects

We investigate how next-generation laser pulses at 10 PW $-$ 200 PW interact with a solid target in the presence of a relativistically underdense preplasma produced by amplified spontaneous emission (ASE). Laser hole boring and relativistic transparency are strongly restrained due to the generation of electron-positron pairs and $\gamma$-ray photons via quantum electrodynamics (QED) processes. A pair plasma with a density above the initial preplasma density is formed, counteracting the electron-free channel produced by the hole boring. This pair-dominated plasma can block the laser transport and trigger an avalanche-like QED cascade, efficiently transfering the laser energy to photons. This renders a 1-$\rm\mu m$-scalelength, underdense preplasma completely opaque to laser pulses at this power level. The QED-induced opacity therefore sets much higher contrast requirements for such pulse in solid-target experiments than expected by classical plasma physics. Our simulations show for example, that proton acceleration from the rear of a solid with a preplasma would be strongly impaired.Comment: 5 figure

Biogeography of Wood-Boring Crustaceans (Isopoda: Limnoriidae) Established in European Coastal Waters

Marine wood-borers of the Limnoriidae cause great destruction to wooden structures exposed in the marine environment. In this study we collated occurrence data obtained from field surveys, spanning over a period of 10 years, and from an extensive literature review. We aimed to determine which wood-boring limnoriid species are established in European coastal waters; to map their past and recent distribution in Europe in order to infer species range extension or contraction; to determine species environmental requirements using climatic envelopes. Of the six species of wood-boring Limnoria previously reported occurring in Europe, only Limnoria lignorum, L. quadripunctata and L. tripunctata are established in European coastal waters. L. carinata and L. tuberculata have uncertain established status, whereas L. borealis is not established in European waters. The species with the widest distribution in Europe is Limnoria lignorum, which is also the most tolerant species to a range of salinities. L. quadripunctata and L. tripunctata appear to be stenohaline. However, the present study shows that both L. quadripunctata and L. tripunctata are more widespread in Europe than previous reports suggested. Both species have been found occurring in Europe since they were described, and their increased distribution is probably the results of a range expansion. On the other hand L. lignorum appears to be retreating poleward with ocean warming. In certain areas (e.g. southern England, and southern Portugal), limnoriids appear to be very abundant and their activity is rivalling that of teredinids. Therefore, it is important to monitor the distribution and destructive activity of these organisms in Europe

Проблеми і шляхи енергоефективної модернізації процесу промивання скерованих свердловин

Окреслено сучасні проблеми нафтогазової енергетики в Україні зокрема процесу буріння і промивання скерованих свердловин. Виділено основні шляхи енергоефективної модернізації процесу промивання скерованих свердловин, що полягають у використанні регульованих приводів бурових насосів старих моделей, облаштуванні бурових установок новими їх модифікаціями однобічної дії або триплексами, зміні продуктивності бурового насоса під час довбання долотом за один рейс, корегуванні продуктивності бурового насоса за механічною швидкістю буріння. Поширене на практиці проектування оптимальної продуктивності бурового насоса провадиться з урахуванням даних про спосіб буріння, діаметри доліт і особливості промивальних систем, профіль свердловини, гранулометричні характеристики шламу. Вибрані значення продуктивності бурового насоса для буріння кожного наступного інтервалу свердловини є незмінними і завищеними. Проте у процесі буріння свердловини зі змінною механічною швидкістю і постійною продуктивністю насоса розосереджений в буровому розчині кільцевого простору об’єм шламу характеризується певною об’ємною концентрацією. Для її врахування і управління продуктивністю бурового насоса у процесі буріння свердловин запропоновано комплекс науково-практичних заходів, який дозволяє покращити стан промивання і зменшити енерговитрати процесу.Modern problems of oil and gas energy in Ukraine and the role of the drilling and washing processes for the directed mining holes are outlined in the article. The basic ways of energy effective process modernization are distinguished. Washing of the directed mining holes, are used in occasions of boring pumps of old models, their arrangement of boring options with their new modifications of one-sided action or triplexes, changing of the productivity of boring pump using a chisel and overriding the productivity of boring pump in the mechanical drilling speed. Optimal productivity of boring pump is widespread in practice takes into account the method of the boring drilling’s data, the diameters of the chisels and washing systems’ features, profile of mining hole, grain-size descriptions of mud. Chosen values of the productivity of boring pump for drilling of every next interval of mining hole are unchanged and overpriced. However, during a well-boring with variable mechanical speed and permanent productivity of pump dispersed in the boring solution of a circular space is characterized by a certain volume concentration. For registration and management of the boring pump’s the productivity we suggest the complex of research and practice steps, that will allow to improve the condition of the washing and decrease the energy consumptions of the well-drilling process

Pair plasma cushions in the hole-boring scenario

Pulses from a 10 PW laser are predicted to produce large numbers of gamma-rays and electron-positron pairs on hitting a solid target. However, a pair plasma, if it accumulates in front of the target, may partially shield it from the pulse. Using stationary, one-dimensional solutions of the two-fluid (electron-positron) and Maxwell equations, including a classical radiation reaction term, we examine this effect in the hole-boring scenario. We find the collective effects of a pair plasma "cushion" substantially reduce the reflectivity, converting the absorbed flux into high-energy gamma-rays. There is also a modest increase in the laser intensity needed to achieve threshold for a non-linear pair cascade.Comment: 17 pages, 5 figures. Accepted for publication in Plasma Physics and Controlled Fusion. Typos corrected, reference update

Fast-Forward Video Based on Semantic Extraction

Thanks to the low operational cost and large storage capacity of smartphones and wearable devices, people are recording many hours of daily activities, sport actions and home videos. These videos, also known as egocentric videos, are generally long-running streams with unedited content, which make them boring and visually unpalatable, bringing up the challenge to make egocentric videos more appealing. In this work we propose a novel methodology to compose the new fast-forward video by selecting frames based on semantic information extracted from images. The experiments show that our approach outperforms the state-of-the-art as far as semantic information is concerned and that it is also able to produce videos that are more pleasant to be watched.Comment: Accepted for publication and presented in 2016 IEEE International Conference on Image Processing (ICIP