Impact Of Surface Temperature Research Articles

Hygrothermal behaviour of external thermal insulation composite systems (ETICS) to withstand biological colonisation

ETICS are multilayer building solutions applied to the building external walls to provide an improved thermal performance to the building envelope. However, several questions have been raised concerning the durability of ETICS, namely related to biological colonisation phenomena. Considering the high susceptibility of ETICS to bio-colonisation, the following research questions arise: (i) what is the impact of surface temperature (ST) and surface relative humidity (SRH) fluctuation on mould growth in ETICS facades? (ii) is it possible to predict mould growth on ETICS under fluctuating conditions considering favourable and unfavourable growth conditions? This study aims to investigate the influence of the hygrothermal behaviour of five different ETICS (with thermal mortars and insulation boards) on mould growth. ETICS were exposed for one year at an urban site in Lisbon, Portugal, facing North, during which the ST and the SRH were monitored. Concurrently, numerical simulations were performed to evaluate the hygrothermal behaviour of the ETICS. Three theoretical indices were applied, using numerically and experimentally obtained values of ST and SRH as input to provide an indication of the risk of mould growth. The results were complemented and validated by assessing the bio-colonisation, water performance and aesthetic properties of the ETICS. Index 1 (percentage of time with SRH ≥80%) indicated similar potential of mould growth for all systems. Both index 2 (percentage of time with SRH = 100%) and index 3 (percentage of time with SRH ≥80% and 15 °C ≤ ST ≤ 30 °C) indicated a higher potential of mould growth for the lime-based ETICS and a lower potential for the acrylic-based ETICS with an EPS-based mortar. Moreover, the lime-based system obtained the highest rate of mould growth after one year of outdoor exposure. Therefore, results suggested that indices 2 and 3 are in agreement with field observations and thus can provide an indication on mould growth for the analysed ETICS. Results also showed that an increase of capillary water absorption after ageing to levels higher than 1 kg/m2 after 24 h in direct contact with water can favour mould growth. Thus, the combination of unfavourable microclimatic conditions (SRH <80%; ST < 15 °C or ST > 30 °C) and surface hydrophobicity are fundamental to avoid mould growth on ETICS, regardless of the incorporation of biocide in the finishing coat composition.

Impact of surface temperature and convective boundary conditions on a Nanofluid flow over a radially stretched Riga plate

The current work provides the optimal homotopic analytical methodology for the steady circulation over a non-isothermal radially stretched Riga plate/disc unit. The attributes of the heat, along with the mass transfer process, are assessed in the existence of variable transport and magnetic features. Radial stretched Riga disc is considered along with additional realistic boundary heating conditions, namely, prescribed surface temperature as well as prescribed surface concentration, convective boundary conditions and also zero mass flux concentration on the surface area of the Riga disc. The model tracks Brownian motion as well as the thermal diffusion of nanoparticles in fluid circulation all at once. Regulating equations, which are highly coupled, are changed right into non-dimensional equations using appropriate transformations of similarity. Through assembling series solutions, the resulting framework is planned and examined. Graphic summaries are offered for the rheological qualities of various parameters in size for velocity, temperature, as well as nanoparticles. The modified Hartman number improves the velocity distribution and reduces the temperature distribution in both prescribed surface temperature and convective boundary condition cases. The effect of the chemical reaction parameter shows the reduced concentration distribution for the prescribed surface temperature case. In contrast, it is precisely the opposite in the convective boundary condition case.

High Rate Pulse-Galvanostatic Anodic Dissolution of Nickel-Chromium Steels in Electrolytes for Their Electrochemical Machining. Impact of Surface Temperature

High Rate Pulse-Galvanostatic Anodic Dissolution of Nickel-Chromium Steels in Electrolytes for Their Electrochemical Machining. Impact of Surface Temperature

Impact of surface temperature on CaSO4 deposition from surface energy perspective

While numerous surface energy-based studies have investigated various aspects of CaSO4 deposition on modified surfaces, the impact of surface temperature though, as a dominant parameter, has not thoroughly been characterized from surface energy perspective. This has led that most previous studies have attained surface energy specifications at ambient temperature for utilization at elevated operating temperatures. The present study examines the impact of surface temperature in the range of 293–368 K, but at a constant bulk temperature less than surface temperature, on surface energy and its sub-components of several metallic surfaces and amorphous carbon-based coatings. Moreover, the influence of surface temperature on the energy of adhesion between CaSO4 precursors and these surfaces, energy of cohesion between precursors as well as wettability of surfaces in terms of spreading coefficient are also investigated. Results showed that the Lewis acid-base sub-component of surface energy experiences profound changes, at least 3-fold increase, with temperature, while it is a maximum of 1.5-fold decrease for the Lifshitz-van der Waals sub-component. A cumulative correlation based on the spreading coefficient is also proposed to project the propensity of investigated surfaces to CaSO4 deposition as a function of temperature and is validated using data from the literature.

Size-dependent survival of European hake juveniles in the Mediterranean Sea

Most studies on European hake focus on the recruitment process and nursery areas, whereas the information is comparatively limited on the ecology of the juvenile stage (ca. second year of life)—the one most exploited by the Mediterranean trawl fisheries. Using information of the MEDITS programme, we provide a spatial and temporal assessment of the influence of body size and growth on hake survival from recruits (age 0) to juveniles (age 1), along with the impact of surface temperature and chlorophyll variability. At a biogeographic scale, size-dependent survival is supported, with areas with higher mean length of recruits and juveniles yielding higher survival. A similar pattern was observed at interannual level in some western Mediterranean areas, also mediated by a density-dependent effect on growth. However, the most recurrent inter-annual pattern was a negative effect of size on survival, which could be attributed to potential ontogenetic changes in catchability and underrepresentation of intra-annual recruitment pulses that are seasonally inaccessible to the MEDITS survey. Results also evidence that survival in the Alboran and Adriatic seas is dependent on the primary production variability, and that Corsica and Sardinia could be potential feeding grounds receiving juveniles from neighbouring areas. The present study reveals the importance of size- and growth-dependent survival in the juvenile stage of European hake in the Mediterranean Sea.

Impact of Surface Temperature and Salinity on the Ratio of Marine Diatoms to Dinoflagellates in the Trevor Channel Area

In an effort to illuminate the factors that influence surface phytoplankton community composition with respect to marine diatoms (Class Bacillariophyceae) and dinoflagellates (Phylum Dinoflagellata), temperature and salinity data were collected. Phytoplankton samples were collected at six surface water locations along the Trevor channel near Bamfield, British Columbia where sampling locations were of known gradients of salinity and temperature. Each sample was analysed under a light microscope, where 2 µL volumes of seawater were counted for both dinoflagellate and diatom abundances. The ratio of diatoms to dinoflagellates was determined by averaging multiple counts of well-mixed samples from each station. Surface temperature and salinity data were collected using individual CTD (Conductivity, Temperature, Depth) casts, where only the surface values were considered. The phytoplankton ratios were then correlated to each of temperature and salinity. It was found with strong positive correlation that conditions with higher salinity favoured dinoflagellate-dominant communities (r = 0.97, p = 0.00013) and conditions with higher temperature favoured diatom-dominant communities (r = 0.92, p = 0.0035). This data may prove useful in studies regarding how small and large scale climatic changes affect phytoplankton community composition, and proves interesting directions in research as to how bottom-up controls on community structure can impact abundances of macro-organisms.

Projected changes of palmer drought severity index under an RCP8.5 scenario

The potential change of drought measured by the Palmer Drought Severity Index (PDSI) is projected by using a coupled climate system model under a Represen- tative Pathway 8.5 (RCP8.5) scenario. The PDSI changes calculated by two potential evapotranspiration algorithms are compared. The algorithm of Thornthwaite equation overestimates the impact of surface temperature on evaporation and leads to an unrealistic increasing of drought frequency. The PM algorithm based on the Pen- man-Monteith equation is physically reasonably and nec- essary for climate change projections. The Flexible Global Ocean-Atmosphere-Land System model, Spectral Version 2 (FGOALS-s2) projects an increasing trend of drought during 2051-2100 in tropical and subtropical areas of North and South America, North Africa, South Europe, Southeast Asia, and the Australian continent. Both the moderate drought (PDSI < -2) and extreme drought (PDSI < -4) areas show statistically significant increasing trends under an RCP8.5 scenario. The uncer- tainty in the model projection is also discussed.

The dependence of surface temperature on IGBTs load and ambient temperature

Currently, older power electronics and electrotechnics are improvement and at the same time developing new and more efficient devices. These devices produce in their activities a significant part of the heat which, if not effectively drained, causing damage to these elements. In this case, it is important to develop new and more efficient cooling system. The most widespread of modern methods of cooling is the cooling by heat pipe. This contribution is aimed at cooling the insulated-gate bipolar transistor (IGBT) elements by loop heat pipe (LHP). IGBTs are very prone to damage due to high temperatures, and therefore is the important that the surface temperature was below 100°C. It was therefore created a model that examined what impact of surface temperature on the IGBT element and heat removal at different load and constant ambient temperature.

Lightning and convective rain over Indian peninsula and Indo-China peninsula

The impact of surface temperature, CAPE, convective cloud cover, outgoing long wave radiation and aerosol concentrations on lightning flashes and convective rainfall in the Indian peninsular and Indo-China peninsular regions are compared. Results showed that the observed relationships between lightning, precipitation and considered parameters are very complicated. An attempt is made to tie these observed results with physical considerations. For better understanding of involved processes, regional scale simulations to replicate the observed features are required.