| 1. |
|
|
| 2. |
|
|
| 3. |
|
|
| 4. |
- Einberg, Gery, et al.
(författare)
-
CFD modelling of an industrial air diffuser : predicting velocity and temperature in the near zone
- 2005
-
Ingår i: Building and Environment. - : Elsevier BV. - 0360-1323 .- 1873-684X. ; 40:5, s. 601-615
-
Tidskriftsartikel (refereegranskat)abstract
- This article describes experimental and modelling results from CFD simulation of an air diffuser for industrial spaces. The main objective of this paper is to validate a manufacturer model of the diffuser. In the air diffuser, the low velocity part is placed on top of a multi-cone diffuser in order to increase airflow rates and maximize the cooling capacity of a single diffuser unit. This kind of configuration should ensure appropriate performance of industrial air diffusers, which is discussed briefly at the end of the article. The paper illustrates the importance of a simulation model jointly with the manufacturer's product model and the grid layout near the ventilation device to achieve accurate results. Parameters for diffuser modelling were adapted from literature and manufacturer's product data. Correct specification of diffuser geometry and numerical boundary conditions for CFD simulations are critical for prediction. The standard k-epsilon model was chosen to model turbulence because it represents the best-known model utilized and validated for air diffuser performance. CFD simulations were compared systematically with data from laboratory measurements; air velocity was measured by ultrasonic sensors. Results show that CFD simulation with a standard k-epsilon model accurately predicts non-isothermal airflow around the diffuser. Additionally, smoke tests revealed that the flow around the diffuser is not completely symmetrical as predicted by CFD. The cause of the observed asymmetry was not identified. This was the main reason why some simulation results deviate from the measured values.
|
|
| 5. |
- Pukkala, Eero, et al.
(författare)
-
Nordic biological specimen banks as basis for studies of cancer causes and control - more than 2 million sample donors, 25 million person years and 100 000 prospective cancers
- 2007
-
Ingår i: Acta Oncologica. - : Informa UK Limited. - 1651-226X .- 0284-186X. ; 46:3, s. 286-307
-
Tidskriftsartikel (refereegranskat)abstract
- The Nordic countries have a long tradition of large-scale biobanking and comprehensive, population-based health data registries linkable on unique personal identifiers, enabling follow-up studies spanning many decades. Joint Nordic biobank-based studies provide unique opportunities for longitudinal molecular epidemiological research. The purpose of the present paper is to describe the possibilities for such joint studies, by describing some of the major Nordic biobank cohorts with a standardised calculation of the cancer incidence in these cohorts. Altogether two million donors have since 1966 donated more than four million biological samples, stored at -20 degrees C to -135 degrees C, to 17 biobank cohorts in Finland, Iceland, Norway and Sweden. As a result of joint database handling principles, the accuracy of personal identifiers and completeness of follow-up for vital status in all participating biobanks was improved. Thereafter, the cancer incidence was determined using follow-up through the national cancer registries. Biobanks based on random samples of population typically showed slightly lower cancer incidence rates than the general population, presumably due to better participation rates among health-conscious subjects. On the other hand, biobanks including samples for viral screening or clinical testing showed 1.5 to 2.1 fold increased incidence of cancer. This excess was very high immediately after sampling, but for some cancer sites remained elevated for years after clinical sampling. So far, more than 100 000 malignant neoplasms have occurred after sample donation, and the annual increase of the cancer cases in these cohorts is about 10 000. The estimates on the population-representativity of the biobanks will assist in interpretation of generalizability of results of future studies based on these samples, and the systematic tabulations of numbers of cancer cases will serve in study power estimations. The present paper summarizes optimal study designs of biobank-based studies of cancer.
|
|
| 6. |
- Viskari, H, et al.
(författare)
-
Relationship between the incidence of type 1 diabetes and maternal enterovirus antibodies : Time trends and geographical variation
- 2005
-
Ingår i: Diabetologia. - : Springer Science and Business Media LLC. - 0012-186X .- 1432-0428. ; 48:7, s. 1280-1287
-
Tidskriftsartikel (refereegranskat)abstract
- Aims/hypothesis: We have previously observed an inverse correlation between the incidence of type 1 diabetes and enterovirus infections in the background population. The aim of this study was to analyse whether maternal enterovirus antibody status, which reflects both the frequency of enterovirus infections and the protection conferred by the mother on the offspring, also correlates with the incidence of type 1 diabetes. Methods: Maternal enterovirus antibodies were analysed from serum samples taken from pregnant women between 1983 and 2001 in Finland and Sweden using enzyme immunoassay and neutralisation assays. Comparable samples were also taken between 1999 and 2001 in countries with a lower incidence of diabetes (Estonia, Germany, Hungary, Israel, Lithuania, Russia). Results: A clear decrease was observed in maternal enterovirus antibody levels over the past 20 years (p<0.0001). The frequency of enterovirus antibodies was higher in countries with a low or intermediate incidence of type 1 diabetes compared with high-incidence countries (p<0.0001). Conclusions/interpretation: These findings are in line with our previous observations supporting the hypothesis that a low frequency of enterovirus infection in the background population increases the susceptibility of young children to the diabetogenic effect of enteroviruses. © Springer-Verlag 2005.
|
|
