Heating Period Research Articles

The Sinister Side of Summer: Revisiting the Dog Days of Nineteenth-Century New York

Seasons form part of changing sensory experiences of urban environments. But it is important to note that, at times, urbanites broke down seasons into smaller slices. The “Dog Days” are a case in point. This term has now passed into urban myth, but the linking of Sirius with the heat of the summer and canine madness during the dog days stretches back to at least the Romans, and was still widely feared and discussed in the nineteenth century. This roundtable intervention aims to recover the meaning and experience of this season within a season using nineteenth-century New York City as a case study. Drawing on newspaper articles, medical reports, and other sources, it will discuss how the dog days were framed as a louche period of sultry heat and canine madness, a time when tempers and the fabric of urban life frayed. Situating itself within urban environmental and sensory history, this essay also aims to bring together climate and animal history. Before the widespread acceptance of germ theory at the end of the nineteenth century, the theory that the heat of the dog days and the strange influence of Sirius caused rabies was hotly debated in the press and among doctors. It also stoked vivid fears of the dog days, which led to material changes in the lives of dogs: muzzling, impoundment, and death. The dog days was a time when the nonhuman agencies of climate and canine seemingly combined in ways that threatened the physical and emotional health of New Yorkers. As such, the dog days stood for the sinister side of summer that was only broken with the arrival of autumnal freshness.

Research on the matching relationship of multi-energy collaborative temperature control in factory farming system based on TRNSYS

In light of the escalating energy crisis and the imperative to address climate change, there exists a pervasive global consensus advocating the reduction of carbon emissions and the exploration of novel energy sources. Despite this consensus, the realm of factory farming continues to rely upon conventional energy sources for heating purposes. This study focuses on the investigation into the multi-energy heating system employed by an aquaculture company in Dalian City. We undertook the optimization of critical parameters within this system and formulate a comprehensive model for the multi-energy system using the TRNSYS transient simulation platform. The optimization process employs the Hooke-Jeeves algorithm, implemented through GenOpt software, with the system annual value cost serving as the objective function. Optimization variables include solar collector area, solar collector slope, thermal storage tank volume, seawater source heat pump power, and wastewater plate heat exchanger area. The findings of this investigation reveal a marked enhancement in the Coefficient of Performance (COP) and overall system performance after optimization. The resultant annual operating cost was $3133.61, indicating a substantial reduction of $1151.86 compared to the pre-optimization period’s cost. The static payback period is determined to be 9.43 years. During the heating period, in contrast to traditional boiler heating, the optimized system manifests a reduction in coal consumption of 4485.03 kg, accompanied by a cumulative decrease in pollutant emissions totaling 11544.46 kg. This substantiates the system’s cumulative economic and environmental viability.

Green Biosynthesis of Silver Nanoparticles Utilizing Monstera deliciosa Leaf Extract and Estimation of its Antimicrobial Characteristics

AbstractHerein, single step biosynthesis of silver nanoparticles (AgNPs) is reported by using AgNO3 and Monstera deliciosa (MD) leaf extract. Spherical AgNPs are obtained with difference in particle sizes and antibacterial activities using two sets of MD leaf extract having different heating periods 5 and 10 min. They are characterized by UV–vis spectroscopy, X‐ray diffraction (XRD), Zeta potential, Attenuated Total Reflectance Infrared Spectroscopy (ATR‐IR), and Field Emission Scanning Electron Microscopy (FE‐SEM). Dynamic Light Scattering (DLS) studies propose two types of AgNPs have hydrodynamic diameters of 104 and 80 nm. Nuclear Magnetic Resonance (NMR), Gas Chromatography‐Mass Spectrometry (GC‐MS), and High Resolution−Mass Spectrometry (HR‐MS) studies, which reveal the presence of various phytochemicals found in MD leaf extract. These biomolecules play a vital role as stabilizing and reducing agents to fabricate stable AgNPs. These AgNPs exhibit strong antibacterial activities having effective zone of inhibition for both Gram‐positive (Staphylococcus aureus, Bacillus subtilis) and Gram‐negative (Escherichia coli, Pseudomonas aeruginosa) microorganisms, nonetheless AgNPs against different fungi (Penicillium sp., Aspergillus flavus, Fusarium oxysporum, Rhizoctonia solani) show non‐antifungal characteristics because of their inert nature. This study suggests that AgNPs can be used in treating bacterial infections and drug delivery also for several therapeutic and diagnostic applications.

Robust inverse parameter fitting of thermal properties from the laser-based Ångstrom method in the presence of measurement noise using physics-informed neural networks (PINNs)

The two-dimensional laser-based Ångstrom method measures the in-plane thermal properties for anisotropic film-like materials. It involves periodic laser heating at the center of a suspended film sample and records its transient thermal response by infrared imaging. These spatiotemporal temperature data must be analyzed to extract the unknown thermal conductivity values in the orthotropic directions, an inverse parameter fitting problem. Previous demonstration of the metrology technique used a least-squares fitting method that relies on numerical differentiation to evaluate the second-order partial derivatives in the differential equation describing transient conduction in the physical system. This fitting approach is susceptible to measurement noise, introducing high uncertainty in the extracted properties when working with noisy data. For example, when noise of a signal-to-noise ratio of 10 is added to simulated amplitude and phase data, the error in the extracted thermal conductivity can exceed 80%. In this work, we introduce a new alternative inverse parameter fitting approach using physics-informed neural networks (PINNs) to increase the robustness of the measurement technique for noisy temperature data. We demonstrate the effectiveness of this approach even for scenarios with extreme levels of noise in the data. Specifically, the PINN-approach accurately extracts the properties to within 5% of the true values even for high noise levels (a signal-to-noise ratio of 1). This offers a promising avenue for improving the robustness and accuracy of advanced thermal metrology tools that rely on inverse parameter fitting of temperature data to extract thermal properties.

Heat stress in symbiotic dinoflagellates: Implications on oxidative stress and cellular changes

Global warming has been shown to harmfully affect symbiosis between Symbiodiniaceae and other marine invertebrates. When symbiotic dinoflagellates (the genus Breviolum) were in vitro exposed to acute heat stress of +7 °C for a period of 5 days, the results revealed the negative impact on all physiological and other cellular parameters measured. Elevated temperatures resulted in a severe reduction in algal density of up to 9.5-fold, as well as pigment concentrations, indicating the status of the physiological stress and early signs of photo-bleaching. Reactive oxygen species (ROS) were increased in all heated dinoflagellate cells, while the antioxidant-reduced glutathione levels initially dropped on day one but increased under prolonged temperature stress. The cell viability parameters were reduced by 97 % over the heating period, with an increased proportion of apoptotic and necrotic cells. Autofluorescence (AF) for Cy5-PE 660-20 was reduced from 1.7-fold at day 1 to up to 50-fold drop at the end of heating time, indicating that the AF changes were highly sensitive to heat stress and that it could be an extremely sensitive tool for assessing the functionality of algal photosynthetic machinery. The addition of the drug 5-AZA-2′-deoxycytidine (5-AZA), which inhibits DNA methylation processes, was assessed in parallel and contributed to some alterations in algal cellular stress response. The presence of drug 5-AZA combined with the temperature stress had an additional impact on Symbiodiniaceae density and cell complexity, including the AF levels. These variations in cellular stress response under heat stress and compromised DNA methylation conditions may indicate the importance of this epigenetic mechanism for symbiotic dinoflagellate thermal tolerance adaptability over a longer period, which needs further exploration. Consequently, the increased ROS levels and changes in AF signals reported during ongoing heat stress in dinoflagellate cells could be used as early stress biomarkers in these microalgae and potentially other photosynthetic species.

Different variations in PM2.5 sources and their specific health risks in different periods in a heavily polluted area of the Beijing-Tianjin-Hebei region of China

The temporal variations in source-specific health risks of airborne particles and the differences in estimated source contributions to PM2.5 mass and PM2.5 exposure in severely polluted areas with the implementation of control measures remain unclear. In this study, PM2.5 samples were collected from a city of heavy pollution in the Beijing-Tianjin-Hebei region of China in two autumn-winter seasons during 2017–2019. The dominant species of PM2.5 was SNA (sum of sulfate, nitrate, and ammonium; 34 %), organic matter (OM; 23 %), and fine soil (15 %). PM2.5 concentration decreased across the years, whereas trace elements and OM showed the largest increases. A positive matrix factorization model combined with a health risk assessment method identified six sources, and quantified their specific health risks. The major sources of PM2.5 mass were secondary source (37 %) and coal combustion (20 %). The health risks (non-cancer risk for children, and cancer risk for children and adults) exceeded the guidelines, and were dominated by industrial processes (38 % and 40 %) and coal combustion (22 % and 52 %). The interannual decline in PM2.5 concentration was mainly due to reductions in biomass burning and soil dust, but the significant increase in health risks was attributed to the enhancement of industrial processes and coal combustion. On clean days, both PM2.5 mass and health risks were significantly affected by industrial processes and soil dust. As PM2.5 pollution increased, secondary source and coal combustion contributed significantly to PM2.5 mass. Coal combustion posed high health risks during pollution and the heating periods, especially in 2018–2019. Mn, Cr, and As were the dominant elements responsible for source-specific health risks. The quantitative result highlights the different responses of PM2.5 mass and health risks to recent mitigation measures, and suggests that both source concentrations and source-specific health risks should be of concern in the future.

Non-negligible secondary contribution to brown carbon in autumn and winter: inspiration from particulate nitrated and oxygenated aromatic compounds in urban Beijing

Abstract. Nitrated aromatic compounds (NACs) and oxygenated derivatives of polycyclic aromatic hydrocarbons (OPAHs) play vital roles within brown carbon (BrC), influencing both climate dynamics and human health to a certain degree. The concentrations of these drug classes were analyzed in PM2.5 from an urban area in Beijing during the autumn and winter of 2017 and 2018. There were four heavy haze episodes during the campaign, two of which happened prior to heating and the other two during heating. During the entire course of sampling, the mean total concentrations of the nine NACs and the eight OPAHs were 1.2–263 and 2.1–234 ng m−3, respectively. The concentrations of both NACs and OPAHs were approximately 2–3 times higher in the heating period than before heating. For NACs, the relative molecular composition did not change significantly before and during heating, with 4-nitrocatechol and 4-nitrophenol demonstrating the highest abundance. For OPAHs, 1-naphthaldehyde was the most abundant species before and during heating, while the relative proportion of anthraquinone increased by more than twice, from 13 % before heating to 31 % during the heating. In Beijing's urban area during autumn and winter, significant sources of NACs and OPAHs have been traced back to automobile emissions and biomass burning activities. Interestingly, it was observed that the contribution from coal combustion increased notably during heating. It is worth noting that the secondary generation of BrC was important throughout the whole sampling period, which was manifested by the photochemical reaction before heating and the aqueous reaction during heating. It was further found that the haze in autumn and winter was nitrate-driven before heating and secondary organic carbon (SOC)-driven during heating, and the secondary formation of BrC increased significantly in pollution events, particularly during heating.

Computational analysis of microgravity and viscous dissipation impact on periodical heat transfer of MHD fluid along porous radiative surface with thermal slip effects

The current thermal slip and Magnetohydrodynamic analysis plays prominent importance in heat insulation materials, polishing of artificial heart valves, heat exchangers, magnetic resonance imaging and nanoburning processes. The main objective of the existing article is to deliberate the impact of thermal slip, thermal radiation and viscous dissipation on magnetized cone embedded in a porous medium under reduced gravitational pressure. Convective heating characteristics are used to increase the rate of heating throughout the porous cone. For viscous flow along a heated and magnetized cone, the conclusions are drawn. The simulated nonlinear partial differential equations are transformed into a dimensionless state by means of suitable non-dimensional variables. The technique of finite differences is implemented to solve the given model with Gaussian elimination approach. The FORTRAN language is used to make uniform algorithm for asymptotic results according to the boundary conditions. The influence of controlling parameters, such as thermal radiation parameter Rd, Prandtl number Pr, porosity parameter Ω, viscous dissipation parameter Ec, δ thermal slip parameter, Rg reduced gravity parameter and mixed convection parameter λ is applied. Graphical representations were created to show the consequences of various parameters on velocity, temperature and magnetic field profiles along with fluctuating skin friction, fluctuating heat and oscillatory current density. It is found that velocity and temperature profile enhances as radiation parameter enhances. It is noted that the amplitude and oscillations in heat transfer and electromagnetic waves enhances as magnetic Prandtl factor increases.

Solar responsive building glazing: Experimental analysis of the impact of photochromic glazing on indoor thermal and luminous conditions

The application of films on conventional glazing aims at increasing the glazing performance by reducing energy needs and increasing indoor comfort. Photochromic films in particular can alter their optical properties due to a chromatic change in response to solar radiation, allowing for reduced glare levels and solar heat gains. However, despite the potential of application, this refurbishment solution is still poorly explored. Therefore, the main purpose of this work was to experimentally evaluate the thermal and luminous performance of a double glazing with and without a photochromic film installed, using two office rooms in Lisbon as case study. An extended field experimental campaign was conducted simultaneously in both offices, where temperature, solar radiation and illuminance levels were collected. The key contribution and novelty of this research lies on the experimental assessment of the thermal and visual comfort conditions with the photochromic film under real-occupancy. Even though the photochromic film significantly increased the surface temperatures of the glazing, the indoor air temperature was not negatively affected, with an increase up to 14 % of working hours with comfortable temperature during the heating period. Illuminance levels on vertical/horizontal plane were reduced by 24/36 % in the presence of the photochromic film, when compared to the clear glazing without film, resulting in an increase of 7 % of working hours with useful illuminance during the heating period, and large areas in the office room with imperceptible daylight glare levels when facing the glazing system. The impact of the film was less noticeable during the cooling period.

Design optimization of an assisted living facility to improve summer thermal comfort in warming climates

Assisted living facilities with optimal summer thermal comfort are necessary to ensure improved quality of life for the older individuals in warming climates. Older individuals are exposed to higher mortality risks during periods of excessive heat. This study aims to identify and optimize key design variables for a passive house certified assisted living facility in Belgium with high comfort expectations using EnergyPlus to improve indoor thermal comfort during extreme climates. The sensitivity analysis used the Standard Regression Coefficient method with Latin Hypercube Sampling for eighteen design variables under four categories: layout, envelope, operation, and system. The analysis identified flat roof and external floor insulation as the most influential parameters, whereas lighting gain and cooling setback temperature were the least influential parameters. Furthermore, optimizing the reference building with the most sensitive design variables using a genetic algorithm based on the NSGA-II method found ideal configurations that would ensure minimum thermal discomfort hours during extreme summers. The study findings provide an evidence-based approach for building engineers and designers for early-stage design of assisted living facilities that maintain optimal comfort in mixed humid climates of Europe.

Estrus detection on different thoroughbred crossbreed horses with vaginal smear and vaginal acidity method

Abstract Breeding manipulation season in racehorses is required to ensure the birth at the specific period (August-December), which will maximize the foal’s age when participating in their first race (July). Therefore, it is important to time the mating of mares using highly accurate estrus detection methods. This research was conducted to identify the differences data using vaginal smear and pH vagina of Thorougbred crossbreed mares in estrus and anestrus phases. Fifteen multiparous mares were conducted with a period of estrus of 19-22d. The result data showed significant differences (P<0.05) in the vaginal cell distribution patterns at each phase of the estrus cycle. The superficial cells predominate (92.43±5.14%) in the estrus phase while significant parabasal cells (87.89±3.09%) predominate in the anestrus phase. The results also showed a significant difference (P<0.05) in vaginal pH which was much more alkaline (8.71±0.25) in the estrus phase while more significantly acidic-normal (6.02±0.26) in the anestrus phase. However, the results showed no difference both in vaginal smear and pH vagina based on pedigree group. Finally, the pattern of superficial cells being more common and vaginal pH levels being higher during estrus may offer a new way to find out when an equine is in estrus.

Changes in the Characteristics of the Heating Period in Moscow Due to Global Climate Warming

Changes in the Characteristics of the Heating Period in Moscow Due to Global Climate Warming

Analysis of the synergistic benefits of typical technologies for pollution reduction and carbon reduction in the iron and steel industry in the Beijing–Tianjin–Hebei region

With its high energy consumption and pollutant emissions, the iron and steel industry is a significant source of air pollution and carbon emissions in the Beijing–Tianjin–Hebei (BTH) region. To improve air quality and reduce greenhouse gas emissions, a series of policies involving ultra-low emission, synergistic reduction of pollution, and carbon application have been implemented in the region. This study has assessed air pollutant and CO2 emission patterns in the iron and steel industry of the region by employing co-control effects coordinate system, marginal abatement cost curve, and numerical modeling, along with the synergistic benefits of typical technologies. The results have demonstrated that: (1) the intensive production activities pertinent to iron and steel enterprises has contributed greatly to the emission in Tangshan and Handan, where the sintering process is the main source of SO2, NOx, PM2.5, and CO, accounting for 64.86%, 55.15%, 29.98%, and 46.43% of the total emissions, respectively. (2) Among the typical pollution control and reduction measures, industrial restructuring and adjustment of the energy-resource structure have led to the greatest effects on emission reduction. Technologies exhibiting great potential in emission reduction and high-cost efficiency such as Blast Furnace Top Gas Recovery Turbine Unit (TRT) need to be promoted. (3) In Tangshan city with the highest level of steel production, the iron and steel production activities contributed to the concentration of 30.51% of PM2.5, 50.67% of SO2, and 42.54% of NO2 during the non-heating period. During the heating period, pollutants pertinent to the combustion of fossil energy for heating have increased, while iron and steel induced emissions have decreased to 23.7%, 34.32%, and 29.13%, respectively. By 2030, it is speculated that the contribution of the iron and steel industry to air quality will be significantly decreased as result of successful implementation of ultra-low emission policies and typical synergistic reduction technologies.

Thermal response to periodic heating of a heat sink incorporating a phase change material

Phase change materials (PCMs) can effectively dampen temperature fluctuations due to their high latent heat capacity, leading to decreased average cooling requirements in various engineering applications. However, there are few design guidelines for PCM-based heat sinks and there is limited experimental research on their performance in high heat flux, periodic heating conditions. In this work, we present a 0-D and 1-D nondimensional analytic model for PCM-based heat sinks subject to sinusoidal heating. We formally define the four possible responses of PCM-based heat sinks and derive expressions to predict their effectiveness. We test experimentally two PCM-based heat sinks to validate these expressions – an air-cooled system and a water-cooled system. The operating PCM is Field's metal (32.5-Bi, 51-In, 16.5-Sn), a eutectic alloy with a melting temperature of 60 °C. Thermocouples are embedded in the system to measure the evolution of the system's temperature over time. We apply a sinusoidal heat input and study the parametric response of these heat sinks under a wide range of heat flux amplitudes (1-100 W/cm2) and periods (5–640 s), while also varying the external heat transfer coefficient (1,700-18,700 W/m2K), ambient temperature (20–45 °C), and thickness of PCM (1–4.4 mm) to comprehensively validate these proposed models. The experimental results are plotted in phase space and show good agreement with the analytic predictions.

Particulate black carbon mass concentrations and the episodic source identification driven by atmospheric blocking effects in Astana, Kazakhstan

Black carbon (BC) is a component of fine particulate matter (PM2.5) that is a key contributor to adverse human health effects and climate forcing. To date, BC mass concentrations and possible sources in Kazakhstan have not been studied. Thus, understanding the temporal variations of BC for a large developing region with a complex climate is useful. In this study, measurements of fine particulate BC mass concentrations in Astana were made from June 2020 to October 2021 by measuring light absorption of PM2.5 on filters. The mean BC concentration was 2.56 ± 1.29 μg m−3 with maximum and minimum monthly mean BC concentrations being 4.56 ± 2.03 μg m−3 and 1.12 ± 0.42 μg m−3 in January 2021 and June 2020, respectively. Temporal analyses of BC, SO2, PM10, NOx, CO, meteorological and atmospheric stability parameters were performed. Aggregated pollutant ‘episodic loadings’ during the heating and non-heating periods were identified. Their relationships with blocking anticyclones and cyclones were investigated by examining the reversal of meridional gradients at 500 hPa geopotential height (GPH) maps and identifying Omega (Ω) and Rex blocking types. Astana has some of the highest BC concentrations of cities worldwide. Seasonal BC source location identification using Conditional Bivariate Probability Function (CBPF) analysis implicated combined heat and power (CHP) plant emissions as the major BC source in Astana. Significant increases in BC concentrations were observed during the cold season due to numerous sources, generally poorer atmospheric dispersion and blocking events. The Concentration Weighted Trajectory (CWT) analysis results showed that the distribution of the 75th percentile of BC during episodic periods actively controlled by blockings exceeding than the entire measurement period, which may reflect cross-border transport and adjacent countries.

The Characteristics and Expression Analysis of the Tomato SlRBOH Gene Family under Exogenous Phytohormone Treatments and Abiotic Stresses.

Respiratory burst oxidase homologs (RBOHs), also known as NADPH oxidases, contribute significantly to the production of ROS in plants, alongside other major sources such as photosynthesis and electron transport in chloroplasts. It has been shown that plant RBOHs play an active role in plant adversity response and electron transport. However, the phylogenetic analysis and characterization of the SlRBOH gene family in tomatoes have not been systematically studied. This study identified 11 SlRBOH genes in the tomato genome using a genome-wide search approach. The physicochemical properties, chromosomal localization, subcellular localization, secondary structure, conserved motifs, gene structure, phylogenetics, collinear relationships, cis-acting elements, evolutionary selection pressures, tissue expressions, and expression patterns under exogenous phytohormones (ABA and MeJA) and different abiotic stresses were also analyzed. We found that the SlRBOHs are distributed across seven chromosomes, collinearity reflecting their evolutionary relationships with corresponding genes in Arabidopsis thaliana and rice. Additionally, all the SlRBOH members have five conserved domains and 10 conserved motifs and have similar gene structures. In addition, the results of an evolutionary selection pressure analysis showed that SlRBOH family members evolved mainly by purifying selection, making them more structurally stable. Cis-acting element analyses showed that SlRBOHs were responsive to light, hormone, and abiotic stresses. Tissue expression analysis showed that SlRBOH family members were expressed in all tissues of tomato to varying degrees, and most of the SlRBOHs with the strongest expression were found in the roots. In addition, the expressions of tomato SlRBOH genes were changed by ABA, MeJA, dark period extension, NaCl, PEG, UV, cold, heat, and H2O2 treatments. Specifically, SlRBOH4 was highly expressed under NaCl, PEG, heat, and UV treatments, while SlRBOH2 was highly expressed under cold stress. These results provide a basis for further studies on the function of SlRBOHs in tomato.

Sources and formation of fine particles and organic aerosols during autumn-winter period in the southern edge of northern China plain

The North China Plain (NCP) experienced significant improvements in air quality in 2018–2022. However, severe pollution episodes still occur frequently during the cold season. The limitations of highly time-resolved measurements hinder understanding the sources and formation mechanisms of pollution episodes, especially the role of organic aerosols (OA). Therefore, we used a Time-of-Flight Aerosol Chemical Speciation Monitor to characterize the aerosol chemical species, variation, and sources of OA during autumn and winter in Luohe, a city in the southern part of the NCP. The results showed that nitrates and organics were the main species of fine particles (PM2.5), accounting for an average of 38.4% and 29.6% of its total mass, respectively. Furthermore, the positive matrix factorization model analyzed the OA in PM2.5 and identified three primary OA and secondary OA related to photochemistry. Primary OA was the dominant contributor throughout the study period (55%), increasing from 50% during the non-heating period to 59% during the heating period. The contribution of photochemically generated oxidized OA remained high (41%) during heavy pollution episodes in the heating period, indicating strong photochemical production during winter. Additionally, most aerosol species and OA factors showed distinct diurnal variations, with lower concentrations during the day, suggesting the influence of the planetary boundary layer and primary emissions. By analyzing the chemical species features of five heavy particulate matter pollution episodes during the study period, we identified three main driving mechanisms for severe pollution events: photochemical processing, photochemical and aqueous-phase production, and local emissions.

Importance of the autoclave testing parameters on the initial stage of corrosion under CO2-containing geothermal environments

Autoclave corrosion testing has been used for many years; however, few have studied the effect of its shortcomings on the formation of corrosion products and corrosion behaviour. In particular, understanding of these effects under high temperature and high pressure (HTHP) is rare. In this study, we highlighted the important parameters such as heating periods, flow rates and volume-to-surface ratios influencing carbon steel corrosion in the early stages. Especially, characterisation and protection behaviour of corrosion products associated with corrosion behaviour in the heating stage under the geothermal CO2-containing environment were systematically studied via mass loss, in-situ electrochemistry and surface analysis techniques. The roles of pCO2, volume-to-surface ratio and flow rate influence the formation of the corrosion products in the early stage are also evaluated.

Circadian temperature rhythm in breeding sows: differences between days in oestrus and anoestrus after weaning

BackgroundMammals are subject to circadian rhythms for the control of various physiological events. One of the parameters known to be subject to variations throughout the day is body temperature, which is also subject to influences such as environmental temperature. However, there are not many studies on these rhythms in breeding sows. The aim of this study was to determine the circadian parameters for body temperature in post-weaning sows during oestrus period, throughout the seasons in a warm climate.ResultsDifferences were observed in inter-daily stability, intra-daily fragmentation and cycle length comparing the summer sows with the other seasons. Differences were also observed in the period that the sows were in oestrus compared to the non-oestrus period for intra-daily fragmentation, with these differences being more important in the warm seasons compared to the cold seasons. The parameters normalised by COSINOR also showed significant differences when comparing seasons, especially in the acrophase of the temperature maximum. Another significant finding was an increase in vaginal temperature during oestrus in sows monitored in summer compared to the other seasons. Correlations between body, vaginal and environmental temperature were observed.ConclusionThere is a seasonal influence on the circadian rhythm of temperature and summer is clearly the season with the greatest differences in circadian parameters when compared to the other seasons. The extreme summer conditions seem to definitely influence this rhythm and make the body and vaginal temperature of the sows different from the rest of the year. The increase in period robustness in both body and vaginal temperature during the days when sows are in oestrus could be related to the hormonal events of oestrus and ovulation and seems to be independent of weather since it occurs in all controlled seasons. However, this robustness is significantly higher in summer than in the other seasons both in the oestrus period and on days when sows are not in oestrus.

Parametric Optothermal Modulation of Carbon Nanooscillator Decorated with Mie Resonant Silicon Particle

AbstractNanomechanical resonators provide a versatile platform for nanoscale mass sensing and force microscopy, as well as for enhancing light‐matter interaction offering unique functionality for optomechanical applications. In this way, discovering new approaches for coupling light with the mechanical degrees of freedom opens the strong desire paths for further developing of nanomechanical technology. Here, the parametric optothermal modulation of hybrid nanomechanical systems consisting of carbon nanowire with a silicon nanoparticle on its top, is reported. The mechanism of the modulation is based on the periodic optical heating of the nanowire and further modulation of the elasticity parameters. Utilizing the silicon nanoparticle provides additional functionality owing to optical absorption enhanced with Mie resonance and the unique feature of optical Raman thermometry enabling optical monitoring of local temperature. It is shown that the parametric mechanism of modulation allows for a significant increase of the optomechanical coupling strength.