Surface Modification Processes for Use in LEO, GEO and Planetary Environments

Компанія ITL Inc. за 30 років своєї діяльності в галузі дослідження космосу розробила ряд унікальних процесів забезпечують нові властивості матеріалів використовуваних в космосі, які піддаються впливу таких космічних факторів на навколоземних (LEO) і, геостаціонарних орбітах (GEO) і в планетарних середовищах, як атомарний кисень, ультрафіолетове випромінювання , заряджені енергетичні частинки, і т.д. Для матеріалів, що літають в місіях на навколоземних орбітах (LEO), атомарний кисень залишається головною небезпекою. Ми розробили ряд процесів по модифікації поверхні, таких як Photosil, Implantox, які дозволяють змінити структуру поверхні багатьох полімерних матеріалів і фарб і зробити їх стійкими до дії атомарного кисню. Для систем, що працюють на геостаціонарних орбітах (GEO), ефекти пов'язані з електричними зарядами на поверхнрсті відносяться до числа основних небезпек. Два процеса поверхневої модифікації, розроблені ITL, успішно вирішили ці проблеми, зберігаючи при цьому, де необхідно, повну радіо проникність матеріалів.ITL Inc. through its 30 years of activities in space exploration developed a number of unique processes for impairing new properties to space-bound materials that are exposed in LEO, GEO and planetary environments to space factors like atomic oxygen, ultraviolet radiation, charged energetic particles, etc. For materials flown in LEO missions, the atomic oxygen remains the major hazard. We developed a number of surface modification processes like Photosil, Implantox to change the surface structure of many polymer materials and paints and make them atomic oxygen resistive. For systems operating in GEO orbits the charging effects are among the major hazards. Two surface modification processed developed by ITL successfully solved these problems, while keeping the RF transparency of materials where necessary.Компания ITL Inc. за 30 лет своей деятельности в области исследования космоса разработала ряд уникальных процессов обеспечивающих новые свойства материалам используемых в космосе, которые подвергаются воздействию таких космических факторов на околоземных (LEO) и, геостационарных орбитах (GEO) и в планетарных средах, как атомарный кислород, ультрафиолетовое излучение, заряженные энергетические частицы, и т.д. Для материалов, летающих в миссиях на околоземных орбитах (LEO), атомарный кислород остается главной опасностью. Мы разработали ряд процессов по модификации поверхности, таких как Photosil, Implantox, которые позволяют изменить структуру поверхности многих полимерных материалов и красок и сделать их устойчивыми к воздействию атомарного кислорода. Для систем, работающих на геостационарных орбитах (GEO), эффекты связанные с электрическими зарядами на поверхнрсти относятся к числу основных опасностей. Два процеса поверхностной модификации, разработанные ITL, успешно решили эти проблемы, сохраняя при этом, где необходимо, полную радио проницаемость материалов

The Sporadic Meteoroid Complex and Spacecraft Risk

The meteoroid population in near-Earth space is typically broken down into two components: shower meteoroids which orbit in collimated streams, and the older sporadic meteoroids which have been dispersed into a much broader uncollimated distribution of orbits. The sporadic meteors dominate the meteoroid flux at Earth in the size range of those particles of the most of the risk to spacecraft (approximately 100 microns to 1 cm). We describe the results of numerical simulations of the sporadic meteoroid complex by full physical modeling of meteoroids from ejection from their parent body through their perturbation by planets and radiation forces though the end of their lives through collision or ejection from the solar system. This model together with comparison with optical and radar measurements of meteoroid fluxes in near Earth space will allow improved assessment of the risk to spacecraft in near-Earth space from the sporadic complex

Менеджмент остаточных напряжений в сварных элементах и конструкциях

Residual stresses introduced before, during or after welding may change considerably the engineering properties of materials and structural components by affecting their fatigue life, distortion, dimensional stability, corrosion resistance, etc. They play an exceptionally significant role in fatigue of welded elements. The concept of residual stress management is helping the welding community to fully understand the effect of residual stresses by addressing major aspects of residual stresses in welds and welded structures. According to the concept three major stages, i.e. RS determination, RS analysis and RS redistribution are considered and evaluated, either experimentally or theoretically to achieve the optimum performance of welded structures. The welding community benefits directly from the RSM concept at all stages of the welding process. This report will provide an overview on the advancements made in addressing the development of instrumentation for providing solutions in the major stages of the RSM concept. New examples of industrial applications of the developed engineering tools for residual stress analysis and fatigue `life improvement of welded elements and structures are given

Ion Beam-Treated Space Polymers: Long-Term Stability in GEO-Simulated Environments

As part of a large program conducted between years 2010 and 2018, a number of ion beam surface treatments and proprietary coatings formed on advanced space polymers by direct ion beam deposition were developed at Integrity Testing Laboratory (ITL) Inc, in Canada. Thistechnology allowed producing surfaces with controlled surface resistivity in a wide range of charge dissipation values, with negligibly low additional RF losses and other important functional properties, that allowed using such treated materials and products in modern space antennae, solar arrays and other external applications on spacecrafts in GEO environment. This paper will present an overview of results achieved throughout the years on enhancement of radiation stability of space polymers that were ion beam treated and coated with special multifunctional thin coatings by direct ion beam deposition. The treated/coated subjects have been ground-based tested in a range of radiation conditions, simulating the GEO radiation environment, conducted in three world-recognized GEO simulation facilities

From Harm to Robustness: A Principled Approach to Vice Regulation

John Stuart Mill’s harm principle maintains that adult behavior cannot justifiably be subject to social coercion unless the behavior involves harm or a significant risk of harm to non-consenting others. The absence of harms to others, however, is one of the distinguishing features of many manifestations of “vices” such as the consumption of alcohol, nicotine, recreational drugs, prostitution, pornography, and gambling. It is with respect to vice policy, then, that the harm principle tends to be most constraining, and some current vice controls, such as prohibitions on drug possession and prostitution, violate Mill’s precept. In the vice arena, we seem to be willing to accept social interference with what Mill termed “self-regarding” behavior. But does that willingness then imply that any social intervention into private affairs is justifiable, that the government has just as much right to outlaw Protestantism, or shag carpets, or spicy foods, as it does to outlaw drugs? In this paper I argue that advances in neuroscience and behavioral economics offer strong evidence that vices and other potentially addictive goods or activities frequently involve less-than-rational choices, and hence are exempt from the full force of the harm principle. As an alternative guide to vice policy, and following some guidance from Mill, I propose the “robustness principle”: public policy towards addictive or vicious activities engaged in by adults should be robust with respect to departures from full rationality. That is, policies should work pretty well if everyone is completely rational, and policies should work pretty well even if many people are occasionally (or frequently) irrational in their vice-related choices. The harm and robustness principles cohere in many ways, but the robustness principle offers more scope for policies that try to direct people “for their own good,” without opening the door to tyrannical inroads upon self-regarding behavior

Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects

BACKGROUND: Behavioral studies have provided evidence for an action-sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes. METHODOLOGY/PRINCIPAL FINDINGS: Participants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition. CONCLUSIONS/SIGNIFICANCE: The present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction

Fluid loading therapy to prevent spinal hypotension in women undergoing elective caesarean section Network meta-analysis, trial sequential analysis and meta-regression

BACKGROUND Fluid loading is one of the recognised measures to prevent hypotension due to spinal anaesthesia in women scheduled for a caesarean section. OBJECTIVE We aimed to evaluate the current evidence on fluid loading in the prevention of spinal anaesthesia-induced hypotension. DESIGN Systematic review and network meta-analysis with trial sequential analy

The effects of “pulling levers” focused deterrence strategies on crime

A number of American police departments have been experimenting with new problem-oriented policing frameworks to prevent gang and group-involved violence generally known as the “pulling levers” focused deterrence strategies. Focused deterrence strategies honor core deterrence ideas, such as increasing risks faced by offenders, while finding new and creative ways of deploying traditional and non-traditional law enforcement tools to do so, such as directly communicating incentives and disincentives to targeted offenders. Pioneered in Boston to halt serious gang violence, the focused deterrence framework has been applied in many American cities through federally sponsored violence prevention programs. In its simplest form, the approach consists of selecting a particular crime problem, such as gang homicide; convening an interagency working group of law enforcement, social-service, and community-based practitioners; conducting research to identify key offenders, groups, and behavior patterns; framing a response to offenders and groups of offenders that uses a varied menu of sanctions (“pulling levers”) to stop them from continuing their violent behavior; focusing social services and community resources on targeted offenders and groups to match law enforcement prevention efforts; and directly and repeatedly communicating with offenders to make them understand why they are receiving this special attention. These new strategic approaches have been applied to a range of crime problems, such as overt drug markets and individual repeat offenders, and have shown promising results in the reduction of crime. Objectives: To synthesize the extant evaluation literature and assess the effects of pulling levers focused deterrence strategies on crime. Conclusions: We conclude that pulling levers focused deterrence strategies seem to be effective in reducing crime. However, we urge caution in interpreting these results because of the lack of more rigorous randomized controlled trials in the existing body of scientific evidence on this approach

Paternal Care in Biparental Rodents: Intra- and Inter-individual Variation

Parental care by fathers, although rare among mmmals, can be essential for the survival and normal development of offspring in biparental species. A growing body of research on biparental rodents has identified several developmental and experiential influences on paternal responsiveness. Some of these factors, such as pubertal maturation, interactions with pups, and cues from a pregnant mate, contribute to pronounced changes in paternal responsiveness across the course of the lifetime in individual males. Others, particularly intrauterine position during gestation and parental care received during postnatal development, can have long-term effects on paternal behavior and contribute to stable differences among individuals within a species. Focusing on five well-studied, biparental rodent species, we review the developmental and experiential factors that have been shown to influence paternal responsiveness, and consider their roles in generating both intra- and inter-individual variation. We also review hormones and neuropeptides that have been shown to modulate paternal care and discuss their potential contributions to behavioral differences within and between males. Finally, we discuss the possibility that vasopressinergic and possibly oxytocinergic signaling within the brain, modulated by gonadal steroid hormones, may represent the "final common pathway" mediating effects of developmental and experiential variables on intra- and inter-individual variation in paternal care