Point Defect Study in Fe75Al25 and Fe70Al25X5 X=(Cr, Ni) Alloys as a Function of Thermal Treatment by Positron Lifetime Spectroscopy

AbstractPositron lifetime spectroscopy (PALS) is employed to study retained vacancies in Fe75Al25 and Fe70Al25X5 X= (Cr, Ni) after various thermal treatments. The PALS spectra were analyzed with the two states trapping model. The positron lifetime in defects suggests that they are Fe-monovacancies. The vacancy concentration, determined by the rates of trapping positrons to vacancies, strongly depends on the cooling rate of the sample and the ternary addition. An addition of Cr lowers, whereas an addition of Ni increases the concentration of the retained vacancies in relation to Fe75Al25 samples after the same heat treatment

Genetic algorithms for positron lifetime data

Recently, genetic algorithms have been applied for ultrafast optical spectrometry in systems with several convoluted lifetimes. We apply these algorithms and compare the results with POSFIT (by Kirkegaard and Eldrup) and LT programme (by Kansy). The analysis was applied to three types of samples: molybdenum monocrystals, Czochralski-grown silicon with oxygen precipitates, Si with under-surface cavities obtained by He + H ion co- implantation. In all three tests, the genetic algorithm performs very well, in particular for short lifetimes. Further developments to model the resolution function in genetic algorithms are needed

Surface concentration of defects at grain boundaries in sintered alumina determined by positron annihilation lifetime spectroscopy

Sintered alumina samples of grain diameters spanning from 1.2 to 4: 5 ñm have been investigated by positron annihilation lifetime spectroscopy. One series of samples was produced from material containing about 150 ppm impurities (mainly SiO 2 ). T he second one was made from material having about 2700 ppm of various elements (SiO 2 , MgO , CaO). Two models of positron trapping at grain boundari es are compared : The first one relates to the diffusion -limited regime ; and the other one - to the transition -limited regime of trapping. As a result the relative change of surface concentration of defects at grain boundarie s is determined. Additionally , the positron diffusion constant in bulk alumina at room temperature, D + = 0: 3 6 Ï 10 cm 2 /s, is estimated

Properties of neutron doped multicrystalline silicon for solar cells

The technology of neutron transmutation doping of silicon wafers in MARIA nuclear research reactor is described. The studies of the radiation defects performed with positron annihilation confirmed that divacancies dominate in the irradiated material. Thermal treatment of irradiated silicon at 700-1000°C produces void - phosphorus complexes and void aggregates. The resistivity of the samples produced by neutron transmutation doping was found to be uniform within 2.5% limits. The severe reduction of the minority carrier lifetime in irradiated samples was confirmed

A Study of Point Defects in the B2-Phase Region of the Fe-Al System by Mossbauer Spectroscopy

In this work, we employed the Mössbauer spectroscopy and X-ray powder diffraction in a study of point defect formation in intermetallic phases of the B2 structure of the Fe{Al system as a function of Al concentration. The results are compared with the concentrations of point defect determined from positron annihilation data. In the MÄossbauer effect, two types of samples are investigated: Fe{Al alloys with few additives obtained by induction melting and Al-rich metallic powders produced by the self-decomposition method and intensive grinding of high energy in the electro-magneto-mechanical mill. We present the values of the 57Fe isomer shift and quadrupole splitting for the components describing the point defect in the local environment of a MÄossbauer nuclide. The concentration of the Fe vacancies and Fe atoms substituting Al (Fe{AS) are determined. The results showed that an increase in Al content causes an increase in vacancy and Fe{AS concentration

Photo-CIDNP in the reaction center of the diatom Cyclotella meneghiniana observed by 13C MAS NMR

Solid state NMR/Biophysical Organic Chemistr

Higher Programmatic Volume in Neonatal Heart Surgery Is Associated With Lower Early Mortality

BACKGROUND: The early results of congenital heart surgery in neonates remain a challenge. We sought to determine the nature of the association between annual center volume of neonatal cardiac surgery and operative mortality using a multicenter cohort. METHODS: The dataset consists of 27,556 neonatal procedures performed between 1999 and 2015 in 90 centers participating in the European Congenital Heart Surgeons Association database. Centers with mean annual volume load of six or more that submitted data for at least 3 consecutive years were included. World Bank annual gross national index per capita was utilized as an indicator of temporal national affluence. Multilevel logistic regression was used to create a model including the significant risk factors and to calculate odds ratios for operative mortality. Iterative modeling of the dataset incrementally excluding centers with lower annual caseload was used to identify the relationship between annual volume and mortality. RESULTS: In the model thus calculated including The Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery (STAT) mortality score, operative weight and age, noncardiac genetic anomalies, and annual volume of operations were independent risk factors for operative mortality in the analysis of the entire cohort. In the model containing these variables, annual gross national index and year of surgery were not significantly associated with mortality. In the iterative process, annual volume ceased to be a risk factor when units operating on fewer than 60 neonates annually were excluded. CONCLUSIONS: In neonatal congenital heart surgery, the risk of operative death decreased with the increase of volume load. The cutoff point in this cohort was a mean annual volume of 60 neonatal operations per year.info:eu-repo/semantics/publishedVersio

Nuorten tuettu työkokeilu ja -oppisopimus yrityksessä : Vantaan nuorisopalveluiden malli

Alhainen koulutustaso sekä heikko työmarkkinatilanne aiheuttavat merkittäviä syrjäytymisen riskejä useiden nuorten aikuisten elämässä. Nuorten syrjäytyminen on yhteiskunnalle kestämätöntä sekä taloudellisesti, että inhimillisesti. Yksi tapa ehkäistä nuorten syrjäytymistä, on rakentaa heille erilaisia polkuja koulutukseen ja työelämään, sillä koulutuksen katsotaan olevan yksi tehokkaimmista nuorten syrjäytymistä ehkäisevistä toimenpiteistä. Nuoret ovat kiinnostuneita oppisopimuskoulutuksesta muun muassa siksi, että se mahdollistaa toimeentulon ja ammatin hankkimisen samanaikaisesti. Tämän kehittämistyön tavoitteena oli rakentaa ja kuvata prosessi, jonka avulla pääsääntöisesti 18-28-vuotiaat nuoret aikuiset voivat ohjautua Vantaan nuorisopalveluiden kautta työkokeiluun ja oppisopimuskoulutukseen yrityksiin tuetusti. Mallin kehittämisessä on huomioitu sellaisia erityispiirteitä, jotka oppisopimuskoulutuksessa koskevat kouluttamattomia, työttömiä nuoria, joilla on vähän työkokemusta ja jotka tarvitsevat monenlaista tukea. Kehittämistyön laajana tavoitteena voidaan pitää nuorisotakuun toteuttamista paikallisen innovaation avulla, monialaisena yhteistyönä. Opinnäytetyö toteutettiin työelämän kehittämistoimintana, jossa hyödynnettiin aineistona aikaisempia tutkimuksia, raportteja ja selvityksiä sekä monialaisen työryhmän pitkää käytännön kokemusta nuorisotyöstä, nuorten oppisopimustoiminnasta sekä nuorten sosiaalisesta tukemisesta ja vahvistamisesta. Tuloksista käy ilmi, että nuorten oppisopimuskoulutuksessa on tärkeää huomioida kokemattomien nuorten erityinen tuen tarve työpaikoilla tapahtuvassa koulutuksessa. Nuorten kannalta tärkeää on esimerkiksi laadukas työpaikkaohjaus sekä vertaistuki. Nuoret ja työpaikat myös hyötyvät työpaikan ulkopuolisesta, henkilökohtaisesta ohjauksesta ja tuesta, jota voidaan tarjota esimerkiksi nuorisotyön kautta ja jonkinlainen oppisopimukseen suuntaava ennakkojakso, kuten työkokeilu tai muu oppisopimukseen orientoiva toiminta, olisi hyvä sekä työpaikan, että nuoren kannalta. Kehittämistyön tuloksena syntyi prosessikaavio, jossa on kuvattu tuetun työkokeilun ja -oppisopimuskoulutuksen prosessin eteneminen pääpiireittäin. Kehitettyä mallia voidaan hyödyntää Vantaan nuorisopalveluiden työpajatoiminnan yritysyhteistyön toteuttamisessa.The low level of education and the weak labor market situation increases the risks of exclusion in the lives of many young adults. The exclusion of young people is unbearable to society both economically and humanly. One way to prevent the exclusion of young people is to build them different paths for education and working life, because education is seen one of the most effective means to prevent the social exclusion of the young. Young people are interested in apprenticeship training, because among other things, it allows livelihood and obtaining a profession at the same time. The main purpose of this Bachelor´s thesis was to construct and describe a process that allows young adults between the ages of 18 and 28 lead through the youth services of Vantaa to supported work try-out and apprenticeship training to the companies. The development of the model has taken into account the special characteristics of apprenticeship training for unskilled, unemployed young people with low work experience and who need a variety of support. The secondary aim of this development work is to implement the youth guarantee through local innovation and with multidisciplinary co-operation. This thesis was carried out as a workplace development activity utilizing previous research, reports and studies as well as a multidisciplinary team with long experience of youth work, youth apprenticeship training and the social support and strengthening of young people. The results show that in the apprenticeship training of young people it is important to take into account the special needs that young inexperienced people have in the workplace education. It is important for young people to have for example high quality workplace guidance and peer support. Young people and workplaces benefit from personal counselling and support which can be provided for them by the outside provider, such as youth work, and also some kind of orientation (advance period) before the apprenticeship contract, such as the work try-out, would be good for both the workplace and the young. As a result of the development work, a process diagram was developed describing the progress of the process of supported work try-out and apprenticeship training. The developed model can be utilized in the workshop activities in company co-operation of the youth services of Vantaa

Das Tumormikromilieu bei Speicheldrüsenkarzinomen – mögliche Konsequenzen für neue Therapiekonzepte

Hintergrund Speicheldrüsenkarzinome („salivary gland carcinomas“, SGC) sind seltene Tumoren, die aufgrund ihrer histologischen Vielfalt und den in Abhängigkeit vom Subtyp unterschiedlichen Krankheitsverläufen eine Herausforderung für Diagnostik und Therapie darstellen. Über die Zusammensetzung des Tumormikromilieus (TME) bei SGC ist bislang wenig bekannt. Ein umfassenderes Verständnis der relevanten molekularen Veränderungen und immunologischen Prozesse des Tumors sowie des umgebenden Stromas könnte dazu beitragen, die therapeutische Effizienz – beispielsweise durch eine adjuvante Immunmodulation – zu verbessern. Methoden In diesem Manuskript wurden Ergebnisse aus Studien zusammengefasst, die sich mit der Zusammensetzung des TME bei SGC beschäftigen. Ergebnisse Das Immunzellinfiltrat der verschiedenen Tumorentitäten ist unterschiedlich. Bei einem Drittel der SGC wurde eine Expression des Oberflächenzellrezeptors LAG3 („lymphocyte activation gene 3“) auf tumorinfiltrierenden Lymphozyten beobachtet. LAG3 inhibiert – ähnlich wie CTLA‑4 („cytotoxic T‑lymphocyte antigen 4“) und PD‑1 („programmed cell death 1 protein“) – die zelluläre Proliferation, Aktivierung und Homöostase von antitumoral wirksamen T‑Zellen. Höhere Expressionen sind dabei insbesondere bei den prognostisch ungünstigeren Entitäten wie den Speichelgangkarzinomen und Adenokarzinomen NOS („not otherwise specified“) zu beobachten. Schlussfolgerungen LAG3 ist insbesondere bei aggressiven Entitäten und fortgeschrittenen Tumoren nachzuweisen. Folglich könnte eine Therapie mit LAG3-Inhibitoren eine Therapie bei fortgeschrittenen und metastasierten SGC unterstützen