Plasma dynamics studies in development of IPD method of surface engineering

During the Impulse Plasma Deposition (IPD) process of surface engineering plasma is generated in the working gas due to a high-voltage high-current discharge, ignited within an interelectrode region of a coaxial accelerator. The paper presents computational studies of working medium dynamics during the IPD discharge. Plasma has been investigated with a two-dimensional two-fluid magnetohydrodynamic code. Presented analysis of discharges outside the typical exploitation parameter range increases the understanding of phenomena relevant to process of coatings deposition.Во время процесса импульсного плазменного осаждения (ИПО) в рабочем газе генерируется поверхностная плазма благодаря развитию высокоточного разряда с высоким напряжением, который инициируется в межэлектродном пространстве коаксиального ускорителя. Приведены расчетные исследования динамики средних условий работы во время ИПО-разряда. Плазма исследовалась с помощью двумерного магнитогидродинамического кода для двух жидкостей. Представленный анализ разрядов за пределами типичного диапазона эксплуатации параметров увеличивает понимание явлений, имеющих отношение к процессу нанесения покрытий.Під час процесу імпульсного плазмового осадження (ІПО) в робочому газі генерується поверхнева плазма, через розвиток високоточного розряду з високою напругою, який ініціюється в міжелектродному просторі коаксіального прискорювача. Приведені розрахункові дослідження динаміки середніх умов роботи під час ІПО-розряду. Плазма досліджувалась за допомогою двомірного магнітогідродинамічного коду для двох рідин. Представлений аналіз розрядів за межами типового діапазону експлуатації параметрів збільшує розуміння явищ, що мають відношення до процесу нанесення покриттів

Comparative MHD analysis of IPD plasma accelerator work with different electrode polarization

During the Impulse Plasma Deposition (IPD) process of surface engineering plasma is generated in the working gas due to a high-voltage high-current discharge, ignited within an interelectrode region of a coaxial accelerator. A continually growing demand for deeper understanding of the process was the reason to investigate the plasma flow phenomena numerically. The paper reports computational studies of the IPD accelerator with internal cathode. The detailed structure of the discharge region was described by a two-dimensional, two-fluid magnetohydrodynamic approach. In particular, the presented computations suggest the paraboloidal shape of discharge region for device work with the internal cathode. It has been found that for the considered IPD discharge parameters plasma dynamics differs from commonly accepted pattern of concave current-sheet for negative polarization of electrodes (rod cathode and external tube anode).При імпульсному плазмовому напилюванні (ІПН) плазма генерується з робочого газу унаслідок високовольтного потужнострумового розряду в міжелектродній області коаксіального прискорювача. Зростаючі потреби зрозуміння процесів, що відбуваються у плазмовому потоці, стимулювали проведення чисельного моделювання. Дана робота присвячена комп'ютерним дослідженням ІПН прискорювача з внутрішнім електродом-катодом. Детальна структура розрядної області описана в наближенні двовимірної двурідинної магнітогідродинаміки. Зокрема, представлені розрахунки рекомендують параболічну геометрію розрядної області при роботі з внутрішнім електродом-катодом. Показано, що для розглянутих ІПН розрядівПри импульсном плазменном напылении (ИПН) плазма генерируется из рабочего газа вследствие высоковольтного сильноточного разряда в межэлектродной области коаксиального ускорителя. Возрастающие потребности понимания происходящих процессов в плазменном потоке стимулировали проведение численного моделирования. Данная работа посвящена компьютерным исследованиям ИПН ускорителя с внутренним электродом–катодом. Детальная структура разрядной области описана в приближении двумерной двужидкостной магнитогидродинамики. В частности, представленные расчеты рекомендуют параболическую геометрию разрядной области при работе с внутренним электродом–катодом. Показано, что для рассматриваемых ИПН разрядов динамика плазмы отличается от общепринятой формы вогнутого токового слоя при отрицательной полярности электродов (стержневой катод и внешняя труба- анод)

Contextual determinants of CHILDREN'S health care and policy in Europe

BACKGROUND: The main objective of this study was to explore the contextual determinants of child health policies. METHODS: The Horizon 2020 Models of Child Health Appraised (MOCHA) project has one Country Agent (CA) in all 30 EU and EEA countries. A questionnaire designed by MOCHA researchers as a semi-structured survey instrument asked CAs to identify and report the predominating public and professional discussions related to child health services within the last 5 years in their country and the various factors which may have influenced these. The survey was issued to CAs following validation by an independent Expert Advisory Board. The data were collected between July and December 2016. The data was qualitatively analysed using software Nvivo11 for data coding and categorization and constructing the scheme for identified processes or elements. RESULTS: Contextual determinants of children's health care and policy were grouped into four categories. 1) Socio-cultural determinants: societal activation, awareness, communication, trust, freedom, contextual change, lifestyle, tolerance and religion, and history. 2) Structural determinants which were divided into: a) external determinants related to elements indirectly correlated with health care and b) internal determinants comprising interdependent health care and policy processes. 3) International determinants such as cross-nationality of child health policy issues. 4) The specific situational determinants: events which contributed to intensification of debates which were reflected by behavioural, procedural, institutional and global factors. CONCLUSIONS: The influence of context across European countries, in the process of children's health policy development is clearly evident from our research. A number of key categories of determinants which influence child health policy have been identified and can be used to describe this context. Child health policy is often initiated in reaction to public discontentment. The multiple voices of society resulted, amongst others, in the introduction of new procedures, action plans and guidelines; raising levels of awareness, intensifying public scrutiny, increasing access and availability of services and provoking introduction of structural changes or withdrawing unfavourable changes

How does societal reaction to children's health issues contribute to health policy in Europe? Results of a survey

BACKGROUND: In the European context the awareness of societal responsibility for children's health has increased with greater attention to children's rights and child empowerment processes. Child health issues are considered particularly sensitive; thus, they often provoke strong societal reactions, which, as a consequence, influence national health policies across Europe. Effectiveness of societal influences increases with the involvement of various actors in the context. METHODS: A qualitative approach was used to identify the level of societal involvement in health decision-making. A questionnaire was sent to the Country Agents (CAs) of the Models of Child Health Appraised (MOCHA) project. CAs are contact points in each of the 30 participating in the project countries and were asked to identify strong public and professional discussions related to child health services in their countries. Data collection was undertaken between July and December 2016. RESULTS: Based on 71 case studies, we identified eight thematic patterns, which characterize societal reactions to the currently worrisome child health issues across Europe. We devoted our attention to the three most controversial: child vaccination, child poverty and child abuse. The cases described by the CAs show the broad perspective in the perception of child health problems. Child health issues involve the public and raise nationwide debates. Public concerns were directly or indirectly related to child health and depicted the national overtone. CONCLUSIONS: Concerns in Europe about child health care are twofold: they are devoted to systemic issues (indirect patient orientation) and to child health and well-being (direct patient orientation). The phenomenon of societal responsibility for children's health is important for the support of public acceptance of child health policy

When Covid-19 first struck: analysis of the influence of structural characteristics of countries - technocracy is strengthened by open democracy

Context: The Covid-19 pandemic hit the developed world differentially due to accidental factors, and countries had to respond rapidly within existing resources, structures, and processes to manage totally new health challenges. This study aimed to identify which pre-existing structural factors facilitated better outcomes despite different starting points, as understanding of the relative impact of structural aspects should facilitate achieving optimal forward progress. Methods: Desk study, based on selecting and collecting a range of measures for 48 representative characteristics of 42 countries’ demography, society, health system, and policy-making profiles, matched to three pandemic time points. Different analytic approaches were employed including correlation, multiple regression, and cluster analysis in order to seek triangulation. Findings: Population structure (except country size), and volume and nature of health resources, had only minor links to Covid impact. Depth of social inequality, poverty, population age structure, and strength of preventive health measures unexpectedly had no moderating effect. Strongest measured influences were population current enrolment in tertiary education, and country leaders’ strength of seeking scientific evidence. The representativeness, and by interpretation the empathy, of government leadership also had positive effects. Conclusion: Strength of therapeutic health system, and indeed of preventive health services, surprisingly had little correlation with impact of the pandemic in the first nine months measured in death- or case-rates. However, specific political system features, including proportional representation electoral systems, and absence of a strong single party majority, were consistent features of the most successful national responses, as was being of a small or moderate population size, and with tertiary education facilitated. It can be interpreted that the way a country was lead, and whether leadership sought evidence and shared the reasoning behind resultant policies, had notable effects. This has significant implications within health system development and in promoting the population’s health

Structure of Fe-Cu coatings prepared by the magnetron sputtering method

This work presents the results of our research concerning the synthesis of metallic Fe-Cu coatings by use of the magnetron sputtering method. The structure of the coatings synthesized during two modes of pulsed magnetron sputtering was compared . In our experiment the pulsed magnetron power supply generated a series of pulses gated at 1kHz - standard pulsed mode (SPM) and 2 Hz - low frequency pulsed mode (LFPM). The analysis of the microstructure by means of SEM and TEM show that obtained coatings are characterized by nanocrystalline structure. Additionally the optical emission spectra (OES) during the copper and iron sputtering were measured

Tailored communication methods as key to implementation of evidence-based solutions in primary child health care.

Background: Evidence-based policies should underpin successful implementation of innovations within child health care. The EU-funded Models of Child Health Appraised project enabled research into effective methods to communicate research evidence. The objective of this study was to identify and categorize methods to communicate evidence-based research recommendations and means to tailor this to stakeholder audiences. Methods: We conducted an online survey among national stakeholders in child health. Analysis of the most effective strategies to communicate research evidence and reach the target audience was carried out in order to ensure implementation of optimal child health care models at a national level. Results: Representatives of stakeholders from 21 of the then 30 EU MS and EEA countries responded to the questionnaire. Three main approaches in defining the strategies for effective communication of research recommendations were observed, namely: dissemination of information, involvement of stakeholders and active attitude towards change expressed in actions. The target audience for communicating recommendations was divided int

Deconvolution of Serum Cortisol Levels by Using Compressed Sensing

The pulsatile release of cortisol from the adrenal glands is controlled by a hierarchical system that involves corticotropin releasing hormone (CRH) from the hypothalamus, adrenocorticotropin hormone (ACTH) from the pituitary, and cortisol from the adrenal glands. Determining the number, timing, and amplitude of the cortisol secretory events and recovering the infusion and clearance rates from serial measurements of serum cortisol levels is a challenging problem. Despite many years of work on this problem, a complete satisfactory solution has been elusive. We formulate this question as a non-convex optimization problem, and solve it using a coordinate descent algorithm that has a principled combination of (i) compressed sensing for recovering the amplitude and timing of the secretory events, and (ii) generalized cross validation for choosing the regularization parameter. Using only the observed serum cortisol levels, we model cortisol secretion from the adrenal glands using a second-order linear differential equation with pulsatile inputs that represent cortisol pulses released in response to pulses of ACTH. Using our algorithm and the assumption that the number of pulses is between 15 to 22 pulses over 24 hours, we successfully deconvolve both simulated datasets and actual 24-hr serum cortisol datasets sampled every 10 minutes from 10 healthy women. Assuming a one-minute resolution for the secretory events, we obtain physiologically plausible timings and amplitudes of each cortisol secretory event with R[superscript 2] above 0.92. Identification of the amplitude and timing of pulsatile hormone release allows (i) quantifying of normal and abnormal secretion patterns towards the goal of understanding pathological neuroendocrine states, and (ii) potentially designing optimal approaches for treating hormonal disorders.National Science Foundation (U.S.). Graduate Research Fellowship ProgramNational Institutes of Health (U.S.) (NIH DP1 OD003646)National Science Foundation (U.S.) (0836720)National Science Foundation (U.S.). Office of Emerging Frontiers in Research and Innovation (EFRI-0735956