1,895 research outputs found

    Heavy quark jets at the LHC

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    We summarize measurements of b and c jet production at the LHC, which are an important signature and background for decays of massive particles such as H-to-b-bbar. These include measurements of the inclusive and dijet production of heavy quark jets, b and c jets produced in association with vector bosons Z and W, and decays of boosted Z bosons into pairs of b-bbar. The current status of b tagging and b jet energy scale is also reviewed. These measurements test perturbative QCD in the four and five-flavor number schemes, and provide insight into the relative importance of heavy flavor production through flavor creation, flavor excitation and gluon splitting channels. The W+c measurement provides additionally a powerful way to probe the strange quark and antiquark sea in the proton. The recent studies looking separately at production of one and two b jets find generally good agreement with theory predictions for two b-jet production, while some discrepancies are observed for singly produced b jets, particularly at large b-jet pT , where gluon splitting becomes dominant.Comment: Article submitted to the International Journal of Modern Physics A (IJMPA) as part of the special issue on the "Jet Measurements at the LHC", editor G. Dissertori. 16 pages, 27 figure

    Suojeluskuntatykistö Suomessa

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    Suojeluskuntatykist√∂ oli osa suojeluskuntaj√§rjest√∂n toimintaa. Suojeluskuntatykist√∂ perustettiin virallisesti vuonna 1919, mutta suojeluskuntalaiset vastasivat kolmen patterin toiminnasta Kannaksella jo vapaussodan j√§lkeisin√§ vuosina. Toiminta k√§ynnistyi nopeasti useiden pattereiden perustamisella suojeluskuntien saatua k√§ytt√∂√∂ns√§ tykkej√§. Kentt√§tykist√∂√∂n liittyv√§√§ koulutusta annettiin kymmeniss√§ pattereissa ymp√§ri maan. Koulutuksen tuloksista merkitt√§vimp√§n√§ voidaan pit√§√§ suojeluskuntalaisten j√§rjest√§mi√§ onnistuneita kovapanosammuntoja. T√§m√§n tutkimuksen tutkimusongelma on, millainen oli suojeluskuntatykist√∂n merkitys Suomessa vuosina 1918‚Äď1933. Tutkimustulokseen p√§√§st√§√§n selvitt√§m√§ll√§ ja arvioimalla suojeluskuntatykist√∂n perustamisen syyt, p√§√§m√§√§r√§ sek√§ toteutunut toiminta. Suojeluskuntatykist√∂n joukot ja niiden teht√§v√§t loivat perustan toiminnalle. Toiminnan perusteella voidaan arvioida suojeluskuntatykist√∂n kyky toimia aselajin teht√§viss√§ ja sit√§ kautta arvioida sen merkityst√§. Tutkimus on teoreettinen asiakirjatutkimus, jonka ensisijaisina l√§htein√§ ovat arkistol√§hteet, suojeluskuntatykist√∂st√§ kirjoitetut artikkelit ja suojeluskuntaan sek√§ suomalaiseen kentt√§tykist√∂√∂n liittyv√§ kirjallisuus. Tutkimusmenetelm√§ perustuu aineistol√§hteiden ja kirjallisuuden tutkimiseen sek√§ keskin√§iseen vertailuun eli tutkimusaineiston sis√§lt√∂analyysiin. Suojeluskuntatykist√∂√§ on tutkittu niukasti siit√§ huolimatta, ett√§ tuon ajan kentt√§tykist√∂st√§ on kirjoitettu suhteellisen paljon. Suojeluskuntatykist√∂√§ on k√§sitelty hyvin v√§h√§n suojeluskuntaa k√§sittelev√§ss√§ kirjallisuudessa ja suojeluskunnan lehdiss√§. Suojeluskuntain yliesikunnan tykist√∂asioista eri aikoina vastanneet osastot ovat olleet kuitenkin dokumentoinnissaan aktiivisia ja niiden arkistoista on mahdollista selvitt√§√§ tutkimuksen kannalta olennaiset asiat. Suojeluskuntaj√§rjest√∂ saavutti asemansa vapaussodassa valkoisen osapuolen joukkojen runkona. J√§rjest√∂n asema vakiintui 1920-luvun kuluessa osaltaan sotilaallista koulutusta antavana toimijana tuolloisen puolustusvoimien rinnalle, osaksi yhteiskuntaa. Kentt√§tykist√∂n parissa tapahtui suuria kehitysaskelia 1920-luvun alusta eteenp√§in. Tutkimustuloksina tuon esiin seuraavat kokonaisuudet: Suojeluskuntatykist√∂ perustettiin suunniteltujen suojeluskuntien sodanajan joukkojen tykist√∂ksi. Toiminta muotoutui yksinkertaisemmaksi, kentt√§tykist√∂n koulutusta antavaksi kansalaistoiminnaksi. Saavutukset suojeluskuntatykist√∂ss√§ olivat kuitenkin resurssit huomioiden varsin huomattavat ja toiminta pysyi p√§√§osin mukana aselajin kehityksess√§. Vuonna 1933 siirryttiin liikekannallepanosuunnitelmiin liittyen aluej√§rjestelm√§√§n ja viimeist√§√§n tuolloin oli suojeluskuntatykist√∂n rooli vakiintunut. Talvisotaan perustettiin joitakin joukkoja suojeluskuntatykist√∂n perustalle. P√§√§asiassa suojeluskuntatykist√∂ss√§ palvelleet olivat t√§rke√§ henkil√∂st√∂ryhm√§ suomalaisissa tykist√∂joukoissa

    Suomalaisten yritysjohtajien asenteet venäläisiä kohtaan

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    Tämä opinnäytetyö käsittelee suomalaisten yritysjohtajien asenteita ja mielipiteitä venäläisiä kohtaan. Työssä tutkittiin teoriapohjana Suomea, Venäjää, niiden eroja ja yhtäläisyyksiä sekä kansalaisia. Työssä pyrittiin saamaan selville nykyiset asenteet venäläisiä kohtaan, millaisiksi heidät arvioidaan ja miten he liittyvät otosjoukon liiketoimintaan. Selvityksen lisäksi työssä tehtiin suuntaa antava opastus, miten yrityksissä voitaisiin toimia vastaisuudessa liittyen venäläisiin, niin asiakkaiden kuin työntekijöiden osalta. Olemassaolevat lähteet teoriaan saatiin pääsoin suomalaisista kirjoista mutta myös lehtiartikkeleista ja internetistä. Yritysjohtajille tehtiin kyselylomake osana kvantitiivista tutkimusta ja siitä saatua dataa analysoitiin SPSS Statistics-ohjelmistolla. Kyselystä tuli ilmi, että stereotypiat venäläisiä kohtaan ovat vielä vahvasti elossa; mielipiteet vaihtelivat tuntemuksen ja kokemusten mukaan jopa hyvinkin suuresti. Venäjän-kauppaa tekeville venäläiset ovat tutumpia ja tärkeämpiä, kun taas niitä joilla yhteyksiä Venäjään tai venäläisiin ei ole, he eivät kiinnosta. Venäläiset eivät menestyneet ominaisuuksia arvioitaessa yleisesti, mutta asenteet heitä kohtaan olivat selvästi positiivisempia kun vastauksista oli rajattu mukaan vain ne yritykset, joilla oli venäläisistä kokemusta joko kaupan tai venäjänkielisten työntekijöiden kautta. Negatiiviset stereotypiat voivat haitata yhteistä (kaupallista) kanssakäymistä, ja siksi niitä olisi hyvä muuttaa positiivisempaan suuntaan. Opinnäytetyötä tehdessä tuli ilmi, että paras keino tähän muutokseen on lähestyä sitä tiedon lisäämisen kautta

    Empathy, Challenge, and Psychophysiological Activation in Therapist-Client Interaction

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    Two central dimensions in psychotherapeutic work are a therapist's empathy with clients and challenging their judgments. We investigated how they influence psychophysiological responses in the participants. Data were from psychodynamic therapy sessions, 24 sessions from 5 dyads, from which 694 therapist's interventions were coded. Heart rate and electrodermal activity (EDA) of the participants were used to index emotional arousal. Facial muscle activity (electromyography) was used to index positive and negative emotional facial expressions. Electrophysiological data were analyzed in two time frames: (a) during the therapists' interventions and (b) across the whole psychotherapy session. Both empathy and challenge had an effect on psychophysiological responses in the participants. Therapists' empathy decreased clients' and increased their own EDA across the session. Therapists' challenge increased their own EDA in response to the interventions, but not across the sessions. Clients, on the other hand, did not respond to challenges during interventions, but challenges tended to increase EDA across a session. Furthermore, there was an interaction effect between empathy and challenge. Heart rate decreased and positive facial expressions increased in sessions where empathy and challenge were coupled, i.e., the amount of both empathy and challenge was either high or low. This suggests that these two variables work together. The results highlight the therapeutic functions and interrelation of empathy and challenge, and in line with the dyadic system theory by Beebe and Lachmann (2002), the systemic linkage between interactional expression and individual regulation of emotion.Peer reviewe

    A Note on the Use of Uranine Tracer to Visualize Radionuclide Migration Experiments : Some Observations and Problems

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    Uranine is a dye commonly used in tracer experiments; it is chosen for its high visibility even at low concentrations. Uranine solutions are slightly denser than water at the same temperature. However, in laboratory experiments uranine solutions have been known to occasionally show unpredictable flow behaviors. This paper investigates the possible effect of light-induced density change to explain some of these behaviors. Uranine has a wide light absorption spectrum for visible light, which can heat the dye solution and lower its density to below that of the surrounding water, which induces buoyancy-driven flow. Simulations are made in both one dimension and two dimensions to determine the extent of the effect. The results are then compared to different experiments with unanticipated flow patterns.Peer reviewe

    Consequence assessment of nuclear-powered vessel accidents and floating nuclear power plant transit accidents in the Arctic region

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    Radiological consequence assessment of atmospheric releases of radioactive materials due to accidents on Nuclear-Powered Vessel (NPV) and during a transit of Floating Nuclear Power Plant (FNPP) were performed. The assessment was performed using a probabilistic approach for open sea locations in the Gulf of Finland and near the Norwegian coast in the Barents Sea, and coastal locations nearby the city of Troms√ł and the Kara Strait on the Northern Sea Route. The dose rates and radiation doses to emergency workers and people close to the accident site were estimated, and needed protective actions were evaluated. The decision support system JRODOS was used to model the dispersion and deposition of radioactive substances in atmospheric release and to estimate dose rates and the doses to people and emergency workers. The modelling applied previously published radionuclide inventories and release fractions, and NOMADS weather data from the year 2021. The results showed that for the NPV accidents, external dose rate of 100 őľSv/h, effective dose of 100 mSv, and thyroid equivalent dose of 100 mSv are exceeded nearby the accident locations. Thus, in case there is habitation in the vicinity of the scene, different protective actions are needed downwind from the accident location to protect people. It was estimated that the recommendation to limit being outside is needed up to 10 km, sheltering indoors up to 3 km and evacuation up to 2 km. Furthermore, the iodine prophylaxis for adults may be needed up to 5 km, and rough estimate revealed that iodine prophylaxis for children and pregnant females is needed up to 10 km. Based on the analyses, emergency workers should wear Personal Protective Equipment (PPE) up to about 5 km from the accident site due to the elevated external dose rates. Furthermore, the emergency workers should take iodine prophylaxis if the air contains radioactive iodine, working hours should be recorded, and alarming external dose rate meters and dosimeters should be used. In prolonged situations, the shift work arrangements should also be considered up to 1 km to limit total working time. It is not likely that the higher Operational Intervention Levels (OIL) of 1000 or 10000 őľSv/h are exceeded in the considered NPV accident. In the FNPP transit accident, the effective and thyroid equivalent doses remain below 0.1 mSv and 1 mSv, respectively. Furthermore, the external dose rate of 1 őľSv/h was not exceeded in any of the analyzed release scenarios. It was concluded that it is highly unlikely that any of the protective actions would be needed for the people or emergency workers due to the considered atmospheric releases from the considered FNPP transit accident. Note that the results given are dependent on initial assumptions and are likely to change with assumptions. Ty√∂ss√§ arvioitiin ydink√§ytt√∂isen aluksen (NPV) onnettomuuksien ja kelluvan ydinvoimalaitoksen (FNPP) kuljetusonnettomuudesta aiheutuvan radioaktiivisen ilmakeh√§p√§√§st√∂n seurauksia. Seurausarvio tehtiin hy√∂dynt√§en tilastollisia menetelmi√§ Suomenlahdella ja Barentsinmerell√§ Norjan rannikolla sek√§ Troms√łn ja Karan salmen alueilla Pohjoisella merireitill√§. Annoslaskennan perusteella arvioitiin p√§√§st√∂n aiheuttamaan ulkoista annosnopeutta sek√§ pelastushenkil√∂st√∂n ja v√§est√∂n mahdollista s√§teilyaltistusta. Lis√§ksi arviointiin mahdollisien suojelutoimien tarvetta. P√§√§st√∂n levi√§mis- ja laskeumamallinnus sek√§ annoslaskenta suoritettiin k√§ytt√§en JRODOS -ohjelmistoa. Mallinnuksessa hy√∂dynnettiin aiemmin julkaistuja tietoja laivareaktoreiden radionuklidi-inventaarille ja p√§√§st√∂osuuksille sek√§ globaalia NOMADS-s√§√§dataa vuodelta 2021. Tulokset osoittivat, ett√§ NPV-onnettomuuksissa ulkoinen annosnopeus ylitti 100 őľSv/h ja efektiivinen ja kilpirauhasen ekvivalentti annos ylittiv√§t 100 mSv onnettomuuspaikan l√§heisyydess√§. Jos alueella on asutusta, tuulen alapuolella onnettomuuspaikan l√§hell√§ tarvitaan erilaisia suojelutoimenpiteit√§ ihmisten suojelemiseksi. Arvioitiin, ett√§ suositus ulkona olon rajoittamisesta tarvitaan 10 km:iin, sis√§lle suojautumiseen 3 km:iin ja evakuoimiseksi 2 km:iin saakka. Lis√§ksi joditabletteja tarvitaan aikuisille 5 km:iin sek√§ lapsille ja raskaana oleville 10 km:iin saakka. Arvioiden perusteella s√§teilyty√∂ntekij√∂iden tulisi k√§ytt√§√§ henkil√∂kohtaisia suojavarusteita noin 5 km et√§isyydelle saakka onnettomuuspaikasta korkean ulkoisen annosnopeuden takia. Lis√§ksi h√§t√§ty√∂ntekij√∂iden tulisi ottaa joditabletti, jos p√§√§st√∂ sis√§lt√§√§ radioaktiivista jodia, ty√∂tunnit tulisi kirjata ja ulkoisen annosnopeuden mittareita ja dosimetrej√§ tulisi k√§ytt√§√§. Pitkittyneiss√§ tilanteissa ty√∂aikaa alle 1 km et√§isyydell√§ tulisi rajoittaa hy√∂dynt√§en ty√∂vuoroja. On ep√§todenn√§k√∂ist√§, ett√§ p√§√§st√∂n seurauksena ylittyisi korkeammat ulkoisen annosnopeuden toimenpiderajat (1000 tai 10000 őľSv/h). Havaittiin, ett√§ FNPP-onnettomuudessa efektiivinen annos j√§√§ alle 0,1 mSv:n ja kilpirauhasen ekvivalentti annos j√§√§ alle 1 mSv:n. Analyysin perusteella, ulkoisen annosnopeuden arvo ei ylittynyt 1 őľSv/h mink√§√§n analysoidun p√§√§st√∂n seurauksesta. Voidaan todeta, ett√§ on ep√§todenn√§k√∂ist√§, ett√§ FNPP-onnettomuuden seurauksena mik√§√§n asetetuista annosrajoista tai ohjeellisista toimenpiderajoista ylittyisi laitoksen ulkopuolella

    Electromigration experiments for studying transport parameters and sorption of cesium and strontium on intact crystalline rock

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    This study aims to determine upscaling factors for the radionuclides' distribution coefficients (Kd) on crushed rocks to intact rock for the safety analysis of radionuclide migration from spent nuclear fuel in bedrock towards biosphere. Here we report the distribution coefficients for intact rock determined by electromigration sorption experiments and compare the results with those from recently performed batch sorption experiments. In total 34 rock samples, representing three typical rock types from Olkiluoto Finland, were studied in order to determine distribution coefficients, effective diffusion coefficients and porosities using the electromigration sorption experiments, formation factor experiments and porosity measurement. The parameters determined represent the three main parameters of geosphere used in the safety assessment of spent nuclear fuel disposal. The distribution coefficients of cesium and strontium on intact rock varied between (0.12‚Äď26.2)‚ÄĮ√ó‚ÄĮ10‚ąí3‚ÄĮm3/kg and (1.4‚Äď13.3)‚ÄĮ√ó‚ÄĮ10‚ąí3‚ÄĮm3/kg, respectively, whereas recent results for crushed rock varied between (2‚Äď57)‚ÄĮ√ó‚ÄĮ10‚ąí3‚ÄĮm3/kg and (17‚Äď40)‚ÄĮ√ó‚ÄĮ10‚ąí3‚ÄĮm3/kg, respectively. This implies that crushing increases the distribution coefficient significantly and upscaling factors from 3 to 33 were determined for scaling the distribution coefficients of crushed rock to ones of intact rock. The determined distribution coefficients of cesium and strontium for intact rock can be directly applied in the safety assessment whereas the upscaling factors can be used to convert distribution coefficients determined for crushed rock into ones for intact rock. Based on the results for porosities and effective diffusion coefficients it was concluded that they do not seem to correlate with sorption parameters. However, an alteration state, heterogeneity and mineral content seem to be important factors affecting the distribution coefficients and upscaling factors.Peer reviewe

    Batch sorption experiments of cesium and strontium on crushed rock and biotite for the estimation of distribution coefficients on intact crystalline rock

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    The distribution coefficient (Kd) of radionuclides on bedrock is one of the key parameters used in the safety analysis of spent nuclear fuel repositories. Typically, distribution coefficients have been determined using crushed rock. However, recent studies have shown that crushing of the rock increases considerably the distribution coefficient compared with the values of intact rock. This study aimed to test if batch sorption experiments using different grain sizes (i.e. mean diameter of grains) can be used to evaluate the Kd of strontium (Sr) and cesium (Cs) on intact crystalline rock, which would decrease the needed experimental time compared with transport experiments. Here we report the results of the batch sorption experiments with crushed rocks and compare the results with those from a recent study performed using electromigration experiments with intact drill core samples (Puukko et¬†al., 2018). The batch sorption experiments were done for rock samples from Olkiluoto, Finland, as a function of grain size and of Cs and Sr concentration. Furthermore, the specific surface areas of the same rock samples with different grain sizes were determined. It was shown that Cs distribution coefficients correlate with specific surface areas of the studied rocks and biotite, the correlation coefficient being 0.95. The Cs distribution coefficient was highest for biotite at about 0.1 m3/kg at 10‚ąí4 M cesium concentration and increased systematically to about 1 m3/kg at 10‚ąí8 M. Distribution coefficients for rocks were up to about two orders of magnitude lower, being lowest with the rock with the lowest biotite content (3.3%). The distribution coefficient of Sr varied from 0.04 m3/kg to 0.007 m3/kg and behaved in a different manner: it remained constant in two out of three studied rocks in the concentration range of 10‚ąí8-10‚ąí4 M and only in the case of one rock a decreasing trend was seen at the higher concentration range. It was also shown that batch sorption experiments overestimate the distribution coefficient in respect to intact rock. The decrease of the distribution coefficient as a function of grain size can be estimated using a power law function. It was also shown that estimation of distribution coefficients of Cs and Sr for intact rock by extrapolation of distribution coefficients determined for different grain sizes is not possible without increasing grain size, but in that case diffusion into the grains would also affect the results. A new method was developed for estimating the fraction of the inner surface area of the total surface area of crushed grains. For the mean grain sizes of 0.25 mm and 0.75 mm the fraction of the inner surface was found to be 35‚Äď70% and 60‚Äď90%, respectively. The inner specific surface area was highest with biotite at 1.2 m2/g and lowest with the rock with lowest biotite content (3.3%) at 0.07 m2/g. The surface area analysis revealed that crushing creates and/or allows access to additional inner surface area that is not measured in intact rock. Furthermore, it was demonstrated that sorption of Cs on crushed rock was dominated by mica minerals in multiple concentrations while the effect of mica minerals on the Kd of Sr was not as straightforward.Peer reviewe

    AAV Vector-Mediated Gene Delivery to Substantia Nigra Dopamine Neurons : Implications for Gene Therapy and Disease Models

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    Gene delivery using adeno-associated virus (AAV) vectors is a widely used method to transduce neurons in the brain, especially due to its safety, efficacy, and long-lasting expression. In addition, by varying AAV serotype, promotor, and titer, it is possible to affect the cell specificity of expression or the expression levels of the protein of interest. Dopamine neurons in the substantia nigra projecting to the striatum, comprising the nigrostriatal pathway, are involved in movement control and degenerate in Parkinson's disease. AAV-based gene targeting to the projection area of these neurons in the striatum has been studied extensively to induce the production of neurotrophic factors for disease-modifying therapies for Parkinson's disease. Much less emphasis has been put on AAV-based gene therapy targeting dopamine neurons in substantia nigra. We will review the literature related to targeting striatum and/or substantia nigra dopamine neurons using AAVs in order to express neuroprotective and neurorestorative molecules, as well as produce animal disease models of Parkinson's disease. We discuss difficulties in targeting substantia nigra dopamine neurons and their vulnerability to stress in general. Therefore, choosing a proper control for experimental work is not trivial. Since the axons along the nigrostriatal tract are the first to degenerate in Parkinson's disease, the location to deliver the therapy must be carefully considered. We also review studies using AAV--synuclein (-syn) to target substantia nigra dopamine neurons to produce an -syn overexpression disease model in rats. Though these studies are able to produce mild dopamine system degeneration in the striatum and substantia nigra and some behavioural effects, there are studies pointing to the toxicity of AAV-carrying green fluorescent protein (GFP), which is often used as a control. Therefore, we discuss the potential difficulties in overexpressing proteins in general in the substantia nigra.Peer reviewe

    Cellulose Fibre-Reinforced Biofoam for Structural Applications

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    Traditionally, polymers and macromolecular components used in the foam industry are mostly derived from petroleum. The current transition to a bio-economy creates demand for the use of more renewable feedstocks. Soybean oil is a vegetable oil, composed mainly of triglycerides, that is suitable material for foam production. In this study, acrylated epoxidized soybean oil and variable amounts of cellulose fibres were used in the production of bio-based foam. The developed macroporous bio-based architectures were characterised by several techniques, including porosity measurements, nanoindentation testing, scanning electron microscopy, and thermogravimetric analysis. It was found that the introduction of cellulose fibres during the foaming process was necessary to create the three-dimensional polymer foams. Using cellulose fibres has potential as a foam stabiliser because it obstructs the drainage of liquid from the film region in these gas-oil interfaces while simultaneously acting as a reinforcing agent in the polymer foam. The resulting foams possessed a porosity of approximately 56%, and the incorporation of cellulose fibres did not affect thermal behaviour. Scanning electron micrographs showed randomly oriented pores with irregular shapes and non-uniform pore size throughout the samples.Peer reviewe
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