Warm Side Research Articles

Model-Based Interpretation of Thermal-Gradient Effects in Li-Ion Cells

The present study develops a combined experimental and modeling approach to study temperature gradients in Li-ion batteries. Although through-plane temperature differences may be small (ΔT ≈ 1-10 °C), large interelectrode thermal gradients (∇T ≈ 1,000-10,000 °C/m) can be present and have been found to significantly affect Li-ion battery performance and degradation [1,2]. Figure 1 illustrates a thin pouch cell (order of 300 microns thick) sandwiched between cool and warm plates. The cell uses a graphite anode and a NMC622 cathode. By maintaining the temperature of the cool and warm blocks, a thermal gradient can be enforced across the cell. Depending on how the cell is positioned, the cell’s cathode or anode can be on the cool or warm side. Experiments include overpotential analysis and galvanostatic intermittent titration technique (GITT) at different states of charge. Results show different behaviors as the thermal gradient is applied and the directionality of the thermal gradient changes.This presentation presents a pseudo-two-dimensional (P2D) model [3] that has been modified to represent the experimental conditions, including the thermal gradients. The model considers the temperature dependencies of thermodynamic properties, electrolyte conductivities, electrode diffusion coefficients, intercalation rates, etc. [4]. The model captures some, but not all, of the measured behaviors. Thus, an important objective is to investigate physical and chemical behaviors that are not included in typical P2D models. For example, off-diagonal Onsager contributions could be significant in the presence of high temperature gradients. The results predict how thermal gradients can contribute to Li-ion concentration fluxes (Soret contribution), and thus affect battery performance. The scientific intent is to understand the thermal gradient behaviors and thus assist battery design guidelines and battery-management control considerations. Acknowledgments The authors thank the Office of Naval Research (Dr. Michele Anderson) for financial support (ONR award numbers: N00014-23-1-2694 and N00014-22-1-2411) of this work.

Effect of temperature-dependent and hysteretic sorption in computational mould risk analyses of wood fibreboard sheathing

Wood is known for its complex hygroscopic properties. Previous studies show that both the temperature-dependency and the hysteresis in sorption should be included in the physical models, if the most accurate results are desired from simulations of building assemblies with wood-based materials. Literature is scarce on the topic, where the significance of these aspects on the reliability of mould-risk assessments is inspected. Exterior walls with glass wool insulation and LDF-sheathing were studied by using two different models with previously measured material data. Over 300 hygrothermal simulations were carried out, where mould-indices were computed on the warm side of the sheathing. According to both conventional and more sophisticated model, the studied walls perform well in cold climate if no driving rain leaks in. Temperature-dependent and hysteretic model yields slightly smaller mould-indices in general, but for certain leaky cases the difference is significant, which indicates the importance of sophisticated sorption-properties in modelling.

Gender disparities in thermal responses under vertical air temperature differences

The effects of vertical temperature differences (VTD) on human thermal comfort have attracted growing attention from researchers when utilizing split air conditioners for winter heating. This study underscores the need to investigate the influences of gender disparities in the context of significant vertical temperature variations, a critical aspect that has not yet been comprehensively explored. Twenty gender-balanced subjects were exposed to a variety of stratified thermal environments created by a split air-conditioner. Their overall and local perceptual and physiological responses were measured at various operative temperatures and VTD. Results show that females have lower thermal sensation vote (TSV) and mean skin temperature under the same environments compared to males. Neutral operative temperatures of females and males are 23.7 ˚C and 20.8 ˚C, respectively. On the cold side, lower leg and foot thermal sensations are dominant whereas chest and back are dominant on the warm side. When females rated “slightly warm” (TSV equaled 1) or “warm” (TSV equaled 2), or males rated “slightly cool” (TSV equaled −1), increased VTD can lower thermal acceptability. The research findings have significant implications for the understanding of gender requirements of stratified heating environments and for maximizing the thermal comfort of the two genders.

Қоршау құрылымдарындағы жылу өткізгіш қосындылары

In order to reduce the heat loss of a building and meet the requirements of regulations, multi-storey building envelopes have been widely used in construction in recent years, including the placement of a thermal insulation layer inside the structure. Under the influence of economic considerations, one of the main types of building floors was a masonry cellular concrete block faced with brick with effective insulation between floors. Considering the modernization of existing types of building envelopes and the appearance of a large number of new structures, the question arose about the correct determination of the thermal properties (mainly thermal protection) of such structures. Temperatures are evenly distributed because the heat dissipated over the surface of the structure helps to balance their values when looking at the room. However, the length of the temperature field distortion region increases (due to the presence of interference). On the contrary, the temperature decrease (which extends over a short length of the enclosure) becomes more prominent and noticeable due to inclusions and inclusions located on the warm surface of the structure. Such peculiarities of temperature distribution in the zone of heat conducting inclusions of different types are confirmed by the experience of operation of buildings with corresponding design solutions for panel walls. If the walls at the joints of panels are covered with a thermally conductive protective and finishing layer on the warm side, the temperature distribution over the inner surface of the wall will be uniform; if there is not enough thermal conductive inclusions and inclusions located on the warm surface of the wall, the temperature distribution will be uniform.

The climatology and nature of warm-season convective cells in cold-frontal environments over Germany

Abstract. Cold fronts provide an environment particularly favourable for convective initiation in the mid-latitudes and can also be associated with convective hazards such as flooding, wind, hail and lightning. We build a climatology of cold-frontal convective cells between 2007–2016 for April–September in a cell-front distance framework by combining a radar-based cell detection and tracking dataset and automatic front detection methods applied to reanalysis data. We find that on average around twice as many cells develop on cold-frontal cell days compared to non-cold-frontal cell days. Using the 700 hPa level as a reference point, we show the maximum cell frequency is 350–400 km ahead of the 700 hPa front, which is marginally ahead of the typical surface front location. The 700 hPa front location marks the minimum cell frequency and a clear shift in regime between cells, with a weakened diurnal cycle on the warm side of the 700 hPa cold front and strongly diurnally driven cells on the cold side of the 700 hPa front. High cell frequency is found several hundreds of kilometres ahead of the surface front, and cells in this region are most likely to be associated with mesocyclones, intense convective cores and lightning. Namely, mesocyclones were detected in around 5.0 % of pre-surface-frontal cells compared to only 1.5 % of non-cold-frontal cells. The findings in this study are an important step towards a better understanding of cold-frontal convection climatology and links between cold fronts and convective hazards.

Regional Characteristics of Summer Precipitation Anomalies in the Northeastern Maritime Continent

Based on the monthly mean reanalysis data from NCEP/NCAR (National Centers for Environmental Prediction/ National Center for Atmospheric Research) and GPCP (Global Precipitation Climatology Project) (1979–2020), the regional characteristics of precipitation in the warm pool side of the Maritime Continent (MC) and the relationships between different precipitation patterns and atmospheric circulations are studied. The results show that there are significant correlations as well as differences between the precipitation in the east of the Philippines (area A) and that in the Pacific Ocean near the Northern Mariana Islands (area B). Precipitation in area A is closely related to the eastern Pacific ENSO (El Nino-Southern Oscillation) and EAP/PJ (East Asia-Pacific/Pacific-Japan) teleconnection pattern, while precipitation in area B is linked to the Indian Ocean basin-wide and the South China Sea summer monsoon. When the precipitation anomaly in area A is positive, the East Asian summer monsoon is weak. A cyclone appears to the northwest of area A at 850 hPa with convergence airflow. After filtering out the effects of precipitation in area B, the cyclone retreats to the west, and an anticyclone appears to the southeast of area A. When the precipitation is above normal in area B, the circulation and water vapor transportation are similar to that in area A but more to the east. The updraft and downdrafts to both north and south sides of area B form two closed meridional vertical circulations. When the influence of area A is moved out, the circulation center in the warm pool area moves eastward. This research contributes to a better understanding of the regional characteristics of the Maritime Continent and the East Asian summer monsoon.

Short Warm Distribution Tails Accelerate the Increase of Humid‐Heat Extremes Under Global Warming

AbstractHumid‐heat extremes threaten human health and are increasing in frequency with global warming, so elucidating factors affecting their rate of change is critical. We investigate the role of wet‐bulb temperature (TW) frequency distribution tail shape on the rate of increase in extreme TW threshold exceedances under 2°C global warming. Results indicate that non‐Gaussian TW distribution tails are common worldwide across extensive, spatially coherent regions. More rapid increases in the number of days exceeding the historical 95th percentile are projected in locations with shorter‐than‐Gaussian warm side tails. Asymmetry in the specific humidity distribution, one component of TW, is more closely correlated with TW tail shape than temperature, suggesting that humidity climatology strongly influences the rate of future changes in TW extremes. Short non‐Gaussian TW warm tails have notable implications for dangerous humid‐heat in regions where current‐climate TW extremes approach human safety limits.

Dust impacts on Mongolian cyclone and cold front in East Asia: a case study during 18–22 March 2010

The Gobi Desert in East Asia experiences dust outbreaks during the spring, which are often caused by high winds associated with Mongolian cyclones. The radiative forcing that arises from dust aerosols could affect the intensity and movement of Mongolian cyclones and cold fronts. A case study on a Mongolian cyclone that occurred during 18–22 March 2010 in East Asia examines these factors using an atmosphere-dust coupled model. Our numerical results show that dust’s impact on the intensity of the cyclone and its cold front varies between day and night and depends on the relative position of the weather systems of interest to the dust plume, i.e., the edge or the main dust plume region. When the dust plume approaches the cold front, most of the dust is trapped behind the cold front at low levels, but a small amount of dust extends to the middle levels, thereby reaching the warm side of the middle-level front. As a result, dust weakens the intensity of the low-level front and intensifies the middle-level front during the daytime, modifying the cold front oppositely at night. On the other hand, dust influences the cyclone in two phases. During the first phase, the dust plume edge arrives at the center of the cyclone in the daytime and warms the region, slightly intensifying the cyclone. During the second phase, the major dust plume feeds into the cyclone center in the early morning. The net dust effect is negative, which cools the cyclone center and decreases or stops the intensification. Subsequently, the cyclone is taken over by a nearby cyclonic circulation downstream. The dust plume approaches the new cyclone center, which repeats a similar pattern of intensity change: intensifying and then leveling off. Our results show that dust has no apparent influence on the movement of the cyclone and its cold front for this case study.

Seasonal change and subniche dynamics of three Alexandrium species in the Korea Strait

Some members of the dinoflagellate genus Alexandrium produce toxins responsible for paralytic shellfish poisoning, which causes environmental impacts and large economic losses worldwide. The Outlying Mean Index (OMI) and the Within Outlying Mean Index (WitOMI) were used to examine the ecological niches of three Alexandrium species identifying factors affecting their population dynamics in the Korea Strait (KS). Species niches were divided into seasonal subniches based on species’ temporal and spatial patterns, with A. catenella being highest in the spring, A. pacificum in the summer, and A. affine in the autumn. These shifts in abundance are likely due to changes in their habitat preferences and resource availability, as well as the effects of biological constraints. A subniche-based approach, which considers the interactions between the environment and the biological characteristics of a species, was useful in understanding the factors shaping the population dynamics of the individual species. Additionally, a species distribution model was used to predict the phenology and biogeography of the three Alexandrium species in the KS and their thermal niches on a larger scale. The model predicted that, in the KS, A. catenella exists on the warm side of the thermal niche, while A. pacificum and A. affine exist on the cold side, indicating that these species may respond differently to increases in water temperature. However, the predicted phenology was incongruent with the abundance of the species as measured by droplet digital PCR. Overall, the WitOMI analysis and species distribution model can provide valuable insights into how population dynamics are influenced by the integrated interplay of biotic and abiotic processes.

A Comparison of Thermal Insulation with Interstitial Condensation in Different Climate Contexts in Existing Buildings in Europe

The work presented here investigates the risk of interstitial condensation between the existing masonry and the insulation using several materials and evaluates the water content inside the insulation (WCI) through various simulations in dynamic mode onto existing buildings located in different countries in Europe. The insulation materials considered are specifically: natural fibre materials, mineral fibre materials, and artificial materials. The scenarios were chosen considering different climate zones, according to the Köppen climate classification, and the analysed buildings were taken from the TABULA database in the years of construction from 1945 to 1969. The building typologies are single-family houses, where in each building system the insulation was placed towards the warm side with a fixed thickness of 5 cm. The simulations concerned: (a) the application scenario, (b) the type of stratigraphy chosen, and (c) the exposure of the existing building system. The outputs generated by the simulations provided the data to determine in which type of building, depending on the insulating materials, interstitial condensation is formed or not. It is shown that only for the climate zones of the cities of Oslo and Brussels, associated with their building typologies, for the insulating materials: mineral and natural, is there the formation of interstitial condensation

Association between thermal response and endogenous dopamine: Step-change environments in winter

Temperature step change is the typical transient thermal environment. The purpose of this study was to explore the association of subjective and objective parameters in a step-change environment, including thermal sensation vote (TSV), thermal comfort vote (TCV), mean skin temperature (MST) and endogenous dopamine (DA). Three temperature step changes defined as I3 (15 °C–18 °C to 15 °C), I9 (15 °C–24 °C to 15 °C) and I15 (15 °C–30 °C to 15 °C) were designed for this experiment. Eight male and eight female healthy subjects who participated in the experiment reported thermal perception (TSV and TCV). Skin temperatures of six body parts and DA were measured. Results show that the inverted U-shaped in TSV and TCV was deviated by seasonal factors of the experiment. The deviation direction of TSV in winter was to the warm sensation side, which was opposite to the inherent cold and hot impression of people in winter and summer. The association between dimensionless dopamine (DA*), TSV and MST were described as follows: DA* was the U-shaped change with exposure times when MST was not greater than 31 °C, and TSV was at −2 and −1, and DA* increased with exposure times when MST was greater than 31 °C, and TSV was at 0, 1 and 2. The changes in the body heat storage and autonomous thermal regulation under temperature step changes may potentially be related to the concentration of DA. The human state on thermal nonequilibrium and stronger thermal regulation would correspond to a higher concentration of DA. This work is conducive to exploring the human regulation mechanism in a transient environment.

Emergent thermophoretic behavior in chemical reaction systems

Exposing a solution to a temperature gradient can lead to the accumulation of particles on either the cold or warm side. This phenomenon is known as thermophoresis, and its microscopic origin is still debated. Here, we show that thermophoresis can be observed in any system having internal states with different transport properties, and temperature-modulated rates of transitions between the states. These internal degrees of freedom might be configurational, chemical or velocity states. We also derive an expression for the Soret coefficient, which decides whether particles accumulate on the cold or warm side. Our framework can be applied to any chemical reaction system diffusing in a temperature gradient. It also captures the possibility to observe a sign inversion of the Soret coefficient as the competition between chemical and velocity states. We establish thermophoresis as a genuine non-equilibrium effect, originating from internal microscopic currents consistent with the necessity of transporting heat from warm to cold regions.

Thermal comfort characteristics and heating demand of people with different activity status during extremely cold exposure

Extremely cold weather frequently occurs worldwide, increasing the risk of exposure to extremely cold environments, particularly for outdoor workers. Cold stress can significantly reduce work performance and impair workers’ health and safety. However, few studies have focused on the thermal comfort characteristics and heating demands of people involved in different activities during extremely cold exposure. Herein, 18 male subjects were recruited to perform different activities in a cryogenic chamber with an ambient temperature of −14.0 °C. They underwent 15 min of standing adaptation, 40 min of heating and 15 min of standing recovery. During the heating phase, they experienced four activity status with adjustable heated garments switched on: standing, continuous 4 km/h and 6 km/h walking, and intermittent 4 km/h walking. Variations in subjective perception, physiological responses and heating parameters over time were recorded throughout the experiments. The thermal sensation zone corresponding to thermal comfort shifted and expanded towards the warm side, which may be attributed to local cold exposure. Subjective feedback and self-adjustment were combined to quantify heating demands. Thermal comfort and energy savings were simultaneously considered when determining the heating demand. The comfortable temperature inside the clothes for standing was 23.5–32.9 °C, and active heating was not required for walking at 6 km/h. The actual heating demand decreased with increasing activity intensity and was much lower than the commercially heated garments provided. Heating strategies for different activity status were recommended to guide the design of personal comfort systems.

A Persistent Submesoscale Frontal Slick: A Novel Marker of the Mesoscale Flow Field in a Large Lake (Lake Geneva)

AbstractSubmesoscale fronts often become visible when the accumulation of biosurfactants in the water surface microlayer causes smooth surfaces, called frontal slicks, to develop. Based on in situ and remotely‐sensed data, a frontal slick was documented for the first time in a lake (Lake Geneva). A quasi‐stationary ∼10‐km long slick formed on the warm side of a surface temperature front with strong horizontal velocity strain. The slick width increased from ∼50 to ∼200 m in ∼1.5 hr due to “feeding” by wind‐driven, rapidly‐moving smaller slicks. Numerical modeling results, confirmed by satellite data, indicated that the boundary between mesoscale gyres isolated warm surface water from cold water associated with wind‐induced coastal upwelling. Measurements and modeling suggest that frontogenetic sharpening of the submesoscale temperature gradient created an active front with strong convergent flow. Such dynamics must be considered in buoyant material transport and the vertical exchange of surface water with deeper layers in lakes.

Small‐Scale Spatial Variations of Air‐Sea Heat, Moisture, and Buoyancy Fluxes in the Tropical Trade Winds

AbstractObservations from two autonomous Wave Gliders and six Lagrangian Surface Wave Instrument Float with Tracking drifters in the northwestern tropical Atlantic during the January–February 2020 NOAA Atlantic Tradewind Ocean‐atmosphere Mesoscale Interaction Campaign (ATOMIC) are used to evaluate the spatial variability of bulk air‐sea heat, moisture, and buoyancy fluxes. Sea surface temperature (SST) gradients up to 0.7°C across 10–100 km frequently persisted for several days. SST gradients were a leading cause of systematic spatial air‐sea sensible heat flux gradients, as variations over 5 Wm−2 across under 20 km were observed. Wind speed gradients played no significant role and air temperature adjustments to SST gradients sometimes acted to reduce spatial flux gradients. Wind speed, air temperature, and air humidity caused high‐frequency spatial and temporal flux variations on both sides of SST gradients. A synthesis of observations demonstrated that fluxes were usually enhanced on the warm SST side of gradients compared to the cold SST side, with variations up to 10 Wm−2 in sensible heat and upward buoyancy fluxes and 50 Wm−2 in latent heat flux. Persistent SST gradients and high‐frequency air temperature variations each contributed up to 5 Wm−2 variability in sensible heat flux. Latent heat flux was instead mostly driven by air humidity variability. Atmospheric gradients may result from convective structures or high‐frequency turbulent fluctuations. Comparisons with 0.05°‐resolution daily satellite SST observations demonstrate that remote sensing observations or lower‐resolution models may not capture the small‐scale spatial ocean variability present in the Atlantic trade wind region.

Diabatic processes modulating the vertical structure of the jet stream above the cold front of an extratropical cyclone: sensitivity to deep convection schemes

Abstract. The effect of deep convection parameterisation on the jet stream above the cold front of an explosive extratropical cyclone is investigated in the global numerical weather prediction model ARPEGE, operational at Météo-France. Two hindcast simulations differing only in the deep convection scheme used are systematically compared with each other, with (re)analysis datasets and with NAWDEX airborne observations. The deep convection representation has an important effect on the vertical structure of the jet stream above the cold front at 1-d lead time. The simulation with the less active scheme shows a deeper jet stream, associated with a stronger potential vorticity (PV) gradient in the middle troposphere. This is due to a larger deepening of the dynamical tropopause on the cold air side of the jet and a higher PV destruction on the warm air side, near 600 hPa. To better understand the origin of this stronger PV gradient, Lagrangian backward trajectories are computed. On the cold air side of the jet, numerous trajectories undergo a rapid ascent from the boundary layer to the mid-levels in the simulation with the less active deep convection scheme, whereas they stay at mid-levels in the other simulation. This ascent explains the higher PV noted on that side of the jet in the simulation with the less active deep convection scheme. These ascending air masses form mid-level ice clouds that are not observed in the microphysical retrievals from airborne radar-lidar measurements. On the warm air side of the jet, in the warm conveyor belt ascending region, the Lagrangian trajectories with the less active deep convection scheme undergo a higher PV destruction due to a stronger heating occurring in the lower and middle troposphere. In contrast, in the simulation with the most active deep convection scheme, both the heating and PV destruction extend further up into the upper troposphere.

Synergistic effect of El Ni\xf1o and the North Pacific Oscillation on wintertime precipitation over Southeastern China and the East China Sea Kuroshio area

Wintertime precipitation in China is most pronounced over the southeastern area, and the Kuroshio in the East China Sea anchors a prominent precipitation band over the warm side of the sea surface temperature front. Previous studies have suggested that many factors contribute to the interannual variation of the precipitation over southeastern China (SC), whereas less attention has been paid to precipitation variability over the East China Sea Kuroshio (ECSK) area. This study focuses on the interannual variation of wintertime precipitation over the SC and ECSK areas. Empirical orthogonal function analysis reveals a spatially uniform pattern from SC to the ECSK area. Composite analysis shows that an El Niño event intensifies wintertime precipitation over our target region, and this effect is tripled when an El Niño follows a positive North Pacific Oscillation (NPO) event in the previous winter. The positive NPO event in the previous winter intensifies the El Niño event via the Victoria mode ocean bridge and the subsequent Bjerknes feedback. In comparison with single-factor El Niño events, a much weaker Walker cell induced by the joint event induces a much weaker regional Hadley cell through anomalous descending motion over the western tropical Pacific. The weakened regional Hadley circulation over the western Pacific directly enhances the precipitation over the SC and ECSK area. In this study, the synergistic effect of an El Niño event and a positive NPO event indicates that the influence of the El Niño event can be amplified by the positive NPO event in the previous winter.

The Effects of Environmental Wind Shear Direction on Tropical Cyclone Boundary Layer Thermodynamics and Intensity Change from Multiple Observational Datasets

Abstract The relationship between deep-layer environmental wind shear direction and tropical cyclone (TC) boundary layer thermodynamic structures is explored in multiple independent databases. Analyses derived from the tropical cyclone buoy database (TCBD) show that when TCs experience northerly component shear, the 10-m equivalent potential temperature θe tends to be more symmetric than when shear has a southerly component. The primary asymmetry in θe in TCs experiencing southerly component shear is radially outward from 2 times the radius of maximum wind speed, with the left-of-shear quadrants having lower θe by 4–6 K than the right-of-shear quadrants. As with the TCBD, an asymmetric distribution of 10-m θe for TCs experiencing southerly component shear and a symmetric distribution of 10-m θe for TCs experiencing northerly component shear was found using composite observations from dropsondes. These analyses show that differences in the degree of symmetry near the sea surface extend through the depth of the boundary layer. Additionally, mean dropsonde profiles illustrate that TCs experiencing northerly component shear are more potentially unstable between 500- and 1000-m altitude, signaling a more favorable environment for the development of surface-based convection in rainband regions. Analyses from the Statistical Hurricane Intensity Prediction Scheme (SHIPS) database show that subsequent strengthening for TCs in the Atlantic Ocean basin preferentially occurs in northerly component deep-layer environmental wind shear environments whereas subsequent weakening preferentially occurs in southerly component wind shear environments, which further illustrates that the asymmetric distribution of boundary layer thermodynamics is unfavorable for TC intensification. These differences emphasize the impact of deep-layer wind shear direction on TC intensity changes that likely result from the superposition of large-scale advection with the shear-relative asymmetries in TC structure. Significance Statement This research investigates how the direction of the winds surrounding the storm impacts the strength of a tropical cyclone. Analyses from this study illustrate that when the winds come from the south the atmospheric boundary layer has a cool and dry side along with a warm and moist side. When the large-scale winds come from the north, temperature and moisture conditions are more uniform throughout the boundary layer. Consequently, results from tropical cyclone climatology show that winds observed to come from the north favor subsequent intensification. These relationships illustrate that tropical cyclone structure and intensity are directly influenced by their surrounding environments and that knowledge of the wind environment could help to improve future forecasts of tropical cyclone intensity change.

The effect of genotype, farm and sex on the production traits of fattening pigs of pedigree breed genotypes

The study of the production traits of 22 genotypes of fattening pigs was carried out on two pig farms (Farm A and Farm B) in Central Serbia, under the influence of the following factors: farm, genotype and sex of fattening pigs, and pre-slaughter weight. The characteristics of fattening animals included in the research are: warm carcass side growth (WCSG); bacon thickness - rump (FTR); bacon thickness - back (FTB); bacon thickness - rump + back (FTRB); meat yield - carcass sides (JUSKG) and meat yield in percentage (JUSPRO), as well as weight and ratio of French dressing in warm carcass sides (FDKG and FDPRO). Animals of both sexes were used in the trial (female non-castrated rats and surgically castrated males). Total of 1166 fattening animals were included in the trials. Statistical data processing was performed using the Harvey software package. All included factors in the used models show a highly statistically significant effect on the variation of fattening traits (P<0.01; P<0.001). Animals of genotype DxSL (44.97%) had the highest share of meat in carcass sides, and animals of genotype SL (44.63%) for the trait JUSPRO, while for the trait FDPRO the highest value was recorded for the genotype DXSL (54.45%). In our study, animals of the genotypes (HxD)x(WxD) and Dx(WxD) had the highest values for bacon thickness - 39.95 and 38.32 mm, respectively, which implies lower share of meat in the carcasses. By calculating the genetic and phenotypic correlations, we came to the conclusion that the phenotypic correlation of the carcass side traits was of different strength (from very weak to complete) and different sign, while the genetic correlations were stronger than the phenotypic, so the genetic correlations between the bacon thicknesses FTB and FTR were complete, and between meat yield and traits FTB and FTR complete and negative.

Thermohydraulic performance and effectiveness of a mini shell and tube heat exchanger working with a nanofluid regarding effects of fins and nanoparticle shape

The influence of varied nanoparticle shapes on thermal–hydraulic efficacy of a boehmite nanofluid (BNF) in a mini shell and tube heat exchanger (MSTHX) in the cases of with and without fin is investigated. The five nanoparticle shapes with 90 °C inlet temperature at Reynolds number of 500 for the warm fluid side, and four Reynolds numbers of 500, 1000, 1500, and 2000 with 20 °C inlet temperature for the cold fluid side are considered. The warm fluid is the nanofluid that moves in the tube side, whilst the cool fluid is common water inside the shell side. With elevating Reynolds number, the heat transfer rate (q), overall heat transfer coefficient (U), pressure drop, effectiveness, and number of transfer unit (NTU) increase, while the performance index reduces. By increasing the Reynolds number from 500 to 2000 in the nanofluid having the oblate spheroid nanoparticles, the effectiveness rises 20%, and the performance index reduces 21.7%. The BNF with the platelet additives results in the largest q, whilst the smallest pressure loss is achieved for the Os-shaped additives. Also, the heat transfer rate, U, effectiveness, NTU, performance index, and pressure loss for the MSTHX with fin are larger than those for the MSTHX without fin.