Cavitation inception of a van der Waals fluid at a sack-wall obstacle

Cavitation in a liquid moving past a constraint is numerically investigated by means of a free-energy lattice Boltzmann simulation based on the van der Waals equation of state. The fluid is streamed past an obstacle and, depending on the pressure drop between inlet and outlet, vapor formation underneath the corner of the sack-wall is observed. The circumstances of cavitation formation are investigated and it is found that the local bulk pressure and mean stress are insufficient to explain the phenomenon. Results obtained in this study strongly suggest that the viscous stress, interfacial contributions to the local pressure, and the Laplace pressure are relevant to the opening of a vapor cavity. This can be described by a generalization of Joseph's criterion that includes these contributions. A macroscopic investigation measuring mass flow rate behavior and discharge coefficient was also performed. As theoretically predicted, mass flow rate increases linearly with the square root of the pressure drop. However, when cavitation occurs, the mass flow growth rate is reduced and eventually it collapses into a choked flow state. In the cavitating regime, as theoretically predicted and experimentally verified, the discharge coefficient grows with the Nurick cavitation number

Improving content authoring user experience in the lovelace learning environment

Abstract. This thesis provides the analysis, planning, execution and evaluation of a new back- and frontend prototype of the online learning environment Lovelace created by the project group. The pre-requisite for the prototype was to utilize the same technologies as the current live version, and the project groups first major task was to investigate, comprehend and execute them. In addition, the project group was advised not to review the code of the live version to ensure fresh perspective into execution of the new version. The design takes influence from other sources such as Moodle. This thesis covers the process of the design from first sketches and analysis of the set-out requirements. These requirements include extracting the current editing functionality from separate administrator page to the easily accessible lecture pages editing widget, the static website contents caching, support for the existing Lovelace markup text and many others. The implementation phase starts by following the plan created in the design part which made the process more streamlined. Technical aspects of the development are handled in the implementation part of the thesis. Polymorphism, the way the content is rendered to the viewer, explanation and representation of how content forms and caching works are explored here. The evaluation of the finished prototype was executed in form of measurement of websites load times with addition of an expert evaluation meeting with experienced user of the live version of Lovelace. The meeting consisted of different test cases which the attendee had to complete on both old and new versions. These tasks were all timed and the results were vastly better with the project groups prototype. All of the tasks completed with less time with the prototype, and in some cases even twice as fast. Comparing the end result with the pre-requisites, the requirements were met well, and the improvements were proven to be a success.Tiivistelmä. Tämä tutkielma sisältää verkko-opintoympäristö Lovelacen uuden prototyypin suunnittelun, toteutuksen, analyysin sekä evaluaation vaiheet. Prototyyppi on projektiryhmän tuottama uusi front- ja backend toteutus, jonka esivaatimuksena oli hyödyntää samoja teknologioita kuin alkuperäinen versio. Tämän johdosta projektin keskeisin tehtävä alun kannalta oli tutkia ja opiskella näitä teknologioita perusteellisesti. Lisäksi projektiryhmää ohjeistettiin olemaan katsomatta alkuperäisen version koodia ja toteutusta, jotta projektia lähestyttäisiin täysin uudesta perspektiivistä. Suunnitteluvaiheessa projekti ottaa vaikutteita muista oppimisympäristöistä kuten Moodle:sta. Tämä tutkielma käsittelee suunnitteluprosessin vaiheet mukaanlukien käyttöliittymän luonnokset ja esivaatimusten analyysin. Vaatimuksia ovat editointitoiminnallisuuden siirtäminen erilliseltä ylläpitosivustolta luentosivulta helposti käsiteltävään editointipienoisohjelmaan, välimuistin implementointi latausnopeuksien nopeuttamiseksi, tuki Lovelacen ”markup” -tekstille sekä monia muita. Projektin tekninen puoli, kuten polymorfismi, sisällön renderointi sekä tarkempi välimuistin ja sisältölomakkeiden toiminta käsitellään implementointiosiossa. Valmiin prototyypin evaluointi suoritettiin latausnopeuksien mittauksilla sekä asiantuntijan arvioinnilla. Kyseinen asiantuntija oli kokenut Lovelacen käyttäjä ja hänelle annettiin kolme erilaista tehtävää, jotka hänen kuului suorittaa sekä alkuperäisellä että projektiryhmän versioilla. Nämä suoritukset ajoitettiin sekuntikellolla myöhempää data-analyysia varten. Tulokset prototyyppiversiolla olivat menestyksekkäitä. Tehtäviin kulutettu aika oli jokaisella kerralla lyhyempi prototyyppiä käyttäessä ja joissain tapauksissa jopa kaksi kertaa lyhyempi. Kun kokonaiskuvaa lopputuloksesta verrataan alkuvaatimuksiin, niin huomataan, että vaatimukset tavoitettiin ja uudet toiminnallisuudet paransivat todistetusti käyttäjäkokemusta

Validation of the surgical fear questionnaire in adult patients waiting for elective surgery

Objectives: Because existing instruments for assessing surgical fear seem either too general or too limited, the Surgical Fear Questionnaire (SFQ) was developed. The aim of this study is to assess the validity and reliability of the SFQ. Methods: Based on existing literature and expert consultation the ten-item SFQ was composed. Data on the SFQ were obtained from 5 prospective studies (N = 3233) in inpatient or day surgery patients. These data were used for exploratory factor analysis (EFA), confirmatory factor analysis (CFA), reliability analysis and validity analysis. Results: EFA in Study 1 and 2 revealed a two-factor structure with one factor associated with fear of the short-term consequences of surgery (SFQ-s, item 1-4) and the other factor with fear of the long-term consequences of surgery (SFQ-l, item 5-10). However, in both studies two items of the SFQ-l had low factor loadings. Therefore in Study 3 and 4 the 2-factor structure was tested and confirmed by CFA in an eight-item version of the SFQ. Across all studies significant correlations of the SFQ with pain catastrophizing, state anxiety, and preoperative pain intensity indicated good convergent validity. Internal consistency (Cronbach's alpha) was between 0.765-0.920 (SFQ-total), 0.766-0.877 (SFQ-s), and 0.628-0.899 (SFQ-l). The SFQ proved to be sensitive to detect differences based on age, sex, education level, employment status and preoperative pain intensity. Discussion: The SFQ is a valid and reliable eight-item index of surgical fear consisting of two subscales: fear of the short-term consequences of surgery and fear of the long-term consequences.This study was conducted with departmental funding and supported by a grant from The Netherlands Organisation for Scientific Research (Zon-MW, http://www.zonmw.nl/en/), grant no. 110000007. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Pure and Sb-doped ZrO2 for removal of IO3- from radioactive waste solutions

Peer reviewe

Оптимізація паралельного ітераційного процесу для лінійних систем з розрідженими матрицями

Розглядається один із підходів до побудови передобумовлювача для методу спряжених градієнтів розв'язування СЛАР з розрідженими матрицями нерегулярної структури. Запропоновано та досліджено передобумовлювачі на основі методу паралельних перерізів.Рассматривается один из подходов к построению предобуславливателя для метода сопряженных градиентов решения СЛАУ с разреженными матрицами нерегулярной структуры. Предложены и исследованы предобуславливатели на основе метода параллельных сечений.Considered is one of approaches for construction a preconditioner for method of conjunctive gradients for solution SLAE with sparse matrices of irregular structure. Preconditioners, which are based on method of parallel section, is proposed and investigated

Bacteriological etiology and treatment of mastitis in Finnish dairy herds

Background: The Finnish dairy herd recording system maintains production and health records of cows and herds. Veterinarians and farmers register veterinary treatments in the system. Milk samples for microbiological analysis are routinely taken from mastitic cows. The laboratory of the largest dairy company in Finland, Valio Ltd., analyzes most samples using real-time PCR. This study addressed pathogen-specific microbiological data and treatment and culling records, in combination with cow and herd characteristics, from the Finnish dairy herd recording system during 2010-2012. Results: The data derived from 240,067 quarter milk samples from 93,529 dairy cows with mastitis; 238,235 cows from the same herds served as the control group. No target pathogen DNA was detected in 12% of the samples. In 49% of the positive samples, only one target species and in 19%, two species with one dominant species were present. The most common species in the samples with a single species only were coagulase-negative staphylococci (CNS) (43%), followed by Staphylococcus aureus (21%), Streptococcus uberis (9%), Streptococcus dysgalactiae (8%), Corynebacterium bovis (7%), and Escherichia coli (5%). On average, 36% of the study cows and 6% of the control cows had recorded mastitis treatments during lactation. The corresponding proportions were 16 and 6% at drying-off. For more than 75% of the treatments during lactation, diagnosis was acute clinical mastitis. In the milk samples from cows with a recorded mastitis treatment during lactation, CNS and S. aureus were most common, followed by streptococci. Altogether, 48% of the cows were culled during the study. Mastitis was reported as the most common reason to cull; 49% of study cows and 18% of control cows were culled because of mastitis. Culling was most likely if S. aureus was detected in the milk sample submitted during the culling year. Conclusions: The PCR test has proven to be an applicable method also for large-scale use in bacterial diagnostics. In the present study, microbiological diagnosis was unequivocal in the great majority of samples where a single species or two species with one dominating were detected. Coagulase-negative staphylococci and S. aureus were the most common species. S. aureus was also the most common pathogen among the culled cows, which emphasizes the importance of preventive measures.Peer reviewe

Gene × Physical Activity Interactions in Obesity: Combined Analysis of 111,421 Individuals of European Ancestry

Numerous obesity loci have been identified using genome-wide association studies. A UK study indicated that physical activity may attenuate the cumulative effect of 12 of these loci, but replication studies are lacking. Therefore, we tested whether the aggregate effect of these loci is diminished in adults of European ancestry reporting high levels of physical activity. Twelve obesity-susceptibility loci were genotyped or imputed in 111,421 participants. A genetic risk score (GRS) was calculated by summing the BMI-associated alleles of each genetic variant. Physical activity was assessed using self-administered questionnaires. Multiplicative interactions between the GRS and physical activity on BMI were tested in linear and logistic regression models in each cohort, with adjustment for age, age2, sex, study center (for multicenter studies), and the marginal terms for physical activity and the GRS. These results were combined using meta-analysis weighted by cohort sample size. The meta-analysis yielded a statistically significant GRS × physical activity interaction effect estimate (Pinteraction = 0.015). However, a statistically significant interaction effect was only apparent in North American cohorts (n = 39,810, Pinteraction = 0.014 vs. n = 71,611, Pinteraction = 0.275 for Europeans). In secondary analyses, both the FTO rs1121980 (Pinteraction = 0.003) and the SEC16B rs10913469 (Pinteraction = 0.025) variants showed evidence of SNP × physical activity interactions. This meta-analysis of 111,421 individuals provides further support for an interaction between physical activity and a GRS in obesity disposition, although these findings hinge on the inclusion of cohorts from North America, indicating that these results are either population-specific or non-causal

Lämmöneristeestä voi irrota haitallisia aineita huoneilmaan

Rakennusmateriaalit vaikuttavat sisäilman laatuun. Lämmöneristeinä voidaan käyttää esimerkiksi pellava- ja hamppueristeitä sekä lasi-, kivi- ja selluvillaa. Vertailussa agrokuitueristeet eivät olleet merkittäviä kemiallisten tai hiukkaspäästöjen lähteitä. Kosteuden vaikutuksiin on kuitenkin kiinnitettävä huomiota eristeitä valmistettaessa, varastoitaessa ja asennettaessa, koska korkea ilmankosteus edistää homeiden kasvua eristeessä.vo