Heat transfer characteristics of hydrid microjet-microchannel cooling module

This paper was presented at the 4th Micro and Nano Flows Conference (MNF2014), which was held at University College, London, UK. The conference was organised by Brunel University and supported by the Italian Union of Thermofluiddynamics, IPEM, the Process Intensification Network, the Institution of Mechanical Engineers, the Heat Transfer Society, HEXAG - the Heat Exchange Action Group, and the Energy Institute, ASME Press, LCN London Centre for Nanotechnology, UCL University College London, UCL Engineering, the International NanoScience Community, www.nanopaprika.eu.The paper presents the experimental investigation of heat transfer intensification in a microjetmicrochannel cooling module. Applied technology takes benefits from two very attractive heat removal techniques. When jets are impinging on the surface, they have a very high kinetic energy at the stagnation point, also in microchannels boundary layer is very thin allowing to obtain very high heat fluxes. Main objective of this paper was to experimentally investigate the performance of a microjet-microchannel cooling module. Intense heat transfer in the test section has been examined and described with precise measurements of thermal and flow conditions. Reported tests were conducted under steady state conditions for single phase liquid cooling. Obtained database of experimental data were compared to standard cooling techniques, and compared with superposed semi-empirical models for minichannels and microjet cooling, Mikielewicz and Muszynski (2009). Gathered data with analytical solutions and numerical computer simulation allows the rational design and calculation of hybrid modules and optimum performance of these modules for various industrial applications

Genetic Burden of TNNI3K in Diagnostic Testing of Patients With Dilated Cardiomyopathy and Supraventricular Arrhythmias

BACKGROUND: Genetic variants in TNNI3K (troponin-I interacting kinase) have previously been associated with dilated cardiomyopathy (DCM), cardiac conduction disease, and supraventricular tachycardias. However, the link between TNNI3K variants and these cardiac phenotypes shows a lack of consensus concerning phenotype and protein function. METHODS: We describe a systematic retrospective study of a cohort of patients undergoing genetic testing for cardiac arrhythmias and cardiomyopathy including TNNI3K. We further performed burden testing of TNNI3K in the UK Biobank. For 2 novel TNNI3K variants, we tested cosegregation. TNNI3K kinase function was estimated by TNNI3K autophosphorylation assays.RESULTS: We demonstrate enrichment of rare coding TNNI3K variants in DCM patients in the Amsterdam cohort. In the UK Biobank, we observed an association between TNNI3K missense (but not loss-of-function) variants and DCM and atrial fibrillation. Furthermore, we demonstrate genetic segregation for 2 rare variants, TNNI3K-p.Ile512Thr and TNNI3K-p.His592Tyr, with phenotypes consisting of DCM, cardiac conduction disease, and supraventricular tachycardia, together with increased autophosphorylation. In contrast, TNNI3K-p.Arg556_Asn590del, a likely benign variant, demonstrated depleted autophosphorylation. CONCLUSIONS: Our findings demonstrate an increased burden of rare coding TNNI3K variants in cardiac patients with DCM. Furthermore, we present 2 novel likely pathogenic TNNI3K variants with increased autophosphorylation, suggesting that enhanced autophosphorylation is likely to drive pathogenicity.</p

Response of Scots pine [Pinus sylvestris L.] young-growth stands to an overstorey canopy in the postoutbreak stands in Pila Forests

In the paper the density, height, diameter, slenderness and vitality of the 17 year−old pine young−growth stands depending on the basal area of the shelterwood (four thinning variants: G1−G4). The studies were carried out in eleven 70−90 year−old pine stands heavily damaged in the 80s of the past century by the nun moth (Lymantria monacha L.). With the development of the overstorey the growth, the vitality and the stability of young stands declined. In addition, a decrease in the survival of the young−growth stands under the dense canopy (variant G4) was recorded. A long−term maintenance of young stands under the shelter of the canopy in the areas of low annual precipitation (below 600 mm) requires the reduction of the dbh basal area to the level of at least 15 m3/ha before attaining the age of 15 years

Selection-management in pine stands

This study presents the results on the structure and volume of many−aged pine stands in private forest holdings managed under semi−selection system. Their volume was ca 150 m3/ha and the basal area ca 20 m3/ha. Pine stands reveal all−age structure. The conditions of reaching the multi−generation pine stands is poor habitat where pine regeneration shows high competitive ability and density distribution of trees, including the occurrence of gaps and openings in stand overstorey ensuring proper conditions for the appearance and development of new regenerations of pine

Effect of the upper canopy and removal cutting on the height growth of the pine advance regeneration in Pila Forests

The paper analyses the height growth and the of height increment of the 18 year−old pine advance regeneration under the shelter of varying canopy densities. A significant effect was found of the stocking of the parental stand on the growth of generation. The height increment increased in response to removal cutting (60% in the second year and 80% in the third year after treatment). In drought years, the greatest relative decrease in height growth of the young−growth stands (by ca 40−60%) occurred in the stands of the greatest canopy closure while it did not occur in the stands to which a removal cutting was applied immediately before the drought year

Effect of hornbeam (Carpinus betulus L.) on growth and survival of pedunculate oak (Quercus robur L.) during the thicket stage

Growth and mortality of oak (Quercus robur L.) in young mixed stands with various admixture of hornbeam (Carpinus betulus L.) in the period of 9−13 years after planting were examined. The trial stand is located in central Poland (51.827023° N, 19.922315° E). It was established in 2004 on a moderately fertile site. Four experimental variants with different participation of oak (O) and hornbeam (H) were established: W1 – an oak monoculture (control variant, 100% O), W2 – a mixed stand consisting of two rows of oak and one row of hornbeam (67% O, 33% H), W3 – a mixed stand consisting of one row of oak and one row of hornbeam (50% O, 50% H), W4 – a mixed stand characterized by a single tree mixture, with three oaks and one hornbeam alternately occurring in each row (75% O, 25% H). During the first two years of the study period the height increments of oak trees were significantly larger in the study variants with hornbeam (the biggest in W3 variant), while during the next two years, the largest values of height increments occurred in the control variant (W1). Through the second part of the study period, the most pronounced, negative effect of hornbeam on the dbh increment of oak trees took place in the W3 variant. During the first nine years after planting the survival rate of oak trees in the variants with hornbeam were similar (82−94%) as in the control variant (85%). However, during the next four years, three times more oaks died in W3 variant (16,5%) than in other variants (5−7%). In general, the results obtained suggest that in order to create mixed oak stands with hornbeam as a nursery species, the share of hornbeam should not exceed 20−25% of all planted trees. The above value appears to be acceptable from the point of view of the negative competitive effects of hornbeam on oak trees during the initial stages of stand development