Temperature Humidity Conditions Research Articles

Retreat site occupation and short-term movements in an oasis-dwelling frog in relation to temperature-humidity conditions

The roles of temperature and humidity in shaping diurnal retreat site occupation and short-term movements in amphibians in desert environments have scarcely been studied. In this work, we investigated retreats and movements in the painted frog (Discoglossus pictus auritus) that inhabits oases in arid southern Tunisia, by using a composite temperature-humidity index (THI). Our results show non-random occupation of retreat sites with respect to prevailing temperature-humidity conditions. When leaving retreat sites with THI values above or below their preferred levels, painted frogs tended to move to sites with THI levels more similar to their preferred conditions. We also found that large individuals tended to occupy retreat sites offering similar THI levels, while small individuals moved between sites with very different THI levels, a pattern that could be driven by age-dependent experience. However, there was no significant relationship between the distance moved by painted frogs and the magnitude of the change in the THI between occupied sites. In summary, our findings evidence the role of temperature-humidity conditions in shaping the patterns of diurnal retreat site use in an arid zone amphibian. They also underline the usefulness of composite temperature-humidity indices when assessing amphibian-habitat relationships.

Global risk of heat stress to cattle from climate change

Cattle farming is a major source of global food production and livelihoods that is being impacted by climate change. However, despite numerous studies reporting local-scale heat impacts, quantifying the global risk of heat stress to cattle from climate change remains challenging. We conducted a global synthesis of documented heat stress for cattle using 164 records to identify temperature-humidity conditions associated with decreased production and increased mortality, then projected how future greenhouse gas emissions and land-use decisions will limit or exacerbate heat stress, and mapped this globally. The median threshold for the onset of negative impacts on cattle was a temperature-humidity index of 68.8 (95% C.I.: 67.3–70.7). Currently, almost 80% of cattle globally are exposed to conditions exceeding this threshold for at least 30 days a year. For global warming above 4°C, heat stress of over 180 days per year emerges in temperate regions, and year-round heat stress expands across all tropical regions by 2100. Limiting global warming to 2°C, limits expansion of 180 days of heat stress to sub-tropical regions. In all scenarios, severity of heat stress increases most in tropical regions, reducing global milk yields. Future land-use decisions are an important driver of risk. Under a low environmental protection scenario (SSP3-RCP7.0), the greatest expansion of cattle farming is projected for tropical regions (especially Amazon, Congo Basin, and India), where heat stress is projected to increase the most. This would expose over 500 million more cattle in these regions to severe heat risk by 2090 compared to 2010. A less resource-intensive and higher environmental protection scenario (SSP1-RCP2.6) reduces heat risk for cattle by at least 50% in Asia, 63% in South America, and 84% in Africa. These results highlight how societal choices that expand cattle production in tropical forest regions are unsustainable, both worsening climate change and exposing hundreds of millions more cattle to large increases in severe, year-round heat stress.

Spatial Distribution and Trends of Heat Stress in Vietnam

This study investigates the spatial distribution and trend of heat stress in Vietnam using data from 68 meteorological stations across the country’s seven climatic sub-regions between 1979 and 2018. Daily maximum wet-bulb temperature (TWmax), an indicator of heat stress, was computed based on the daily maximum air temperature (Tx) and relative humidity at 13:00 LST (RH13). Results indicate a strong positive correlation (>0.97) between daily TWmax and Tx and a weaker relationship between daily TWmax and RH13. Tx and TWmax experienced a general increasing trend across most stations over the study period, while RH13 displayed both negative and positive trends. Vietnam’s heat stress thresholds were found to be higher than those in many other parts of the world due to the country’s location and its temperature-humidity conditions. The study identifies most parts of Vietnam have experienced an increase in heat stress days, typically ranging from 5 to 12 days per decade. Among the four seasons, summer contributed the most (50-80%) to the annual number of heat stress days in most sub-regions, except for the Central Highlands and the South where spring had the highest contribution (65-80%). Overall, this study provides useful benchmark values for future research on heat stress in Vietnam.

НАБОР ПРОЧНОСТИ НЕАВТОКЛАВНОГО ПЕНОБЕТОНА НА ОСНОВЕ СИНТЕТИЧЕСКОГО ПЕНООБРАЗОВАТЕЛЯ ПРИ РАЗНЫХ ТЕМПЕРАТУРНО-ВЛАЖНОСТНЫХ УСЛОВИЯХ

The results of determining the compressive strength of non-autoclaved foam concrete based on a synthetic foaming agent at different temperature-humidity conditions are presented

НАБОР ПРОЧНОСТИ НЕАВТОКЛАВНОГО ПЕНОБЕТОНА НА ОСНОВЕ ПРОТЕИНОВОГО ПЕНООБРАЗОВАТЕЛЯ ПРИ РАЗНЫХ ТЕМПЕРАТУРНО-ВЛАЖНОСТНЫХ УСЛОВИЯХ

The results of determining the compressive strength of non-autoclaved foam concrete based on a protein foaming agent under different temperature-humidity conditions are presented

Shrinkage of frame polymer concretes in road construction

It is known that with the same raw material composition, it is possible to obtain different structures of composite materials. So, for example, polymer concretes can be made using traditional technology and the method of phase-by-phase forming. At the same time, frame technology reduces material consumption without loss of strength properties and increases durability. Polymer composite materials of phase-forming by combining properties viscoelastic binder and rigid matrix. It has highly damping performance. The article considers the possibility of using the frame structure polymer composite material in road construction. The composition is also considered, the advantages are determined and a comparison with traditional materials is made. The shrinkage stresses of polymer concrete that occur during the polycondensation reaction of furan resin are quite large and can exceed the permissible ones, which leads to a violation of the monolithic nature of the structure due to the appearance of micro- and macrocracks. In this work, the kinetics of shrinkage within 28 days was studied. The composition of the frame polymer composite material includes the following components: furfural acetone monomer (FAM resin), benzosulfonic acid, granite crushed stone, andesite flour, quartz sand. Theshrinkage of phase-formed polymer concrete was measured on samples hardening under normal temperature-humidity conditions. The generally accepted technique was used, shrinkage deformations were installed along the axis of the sample on two opposite faces with a clock-type indicator with a division price of 0.001 mm. Also in the work is a diagram of the device for determining the deformations of the shrinkage of samples and the results of the study are given. Experimentally established the intensity of shrinkage, which manifests itself in the first three days of curing, in the future its change is insignificant and by the seventh day it fades. According to the test results, it was established that the linear shrinkage of frame polymer concretes is three times less than the shrinkage of polymer concretes with a conventional structure.

Polyurea reinforcement of disintegrated mudstone embankments and the underlying mechanism

Disintegrated mudstone (DM) is often discarded during highway constructions because of its potential continuous disintegration and large wet deformation. The purpose of this study is to improve DM so that it can be used to fill highway embankments. The chemical reinforcement method based on polyurea (PU) was selected to reinforce disintegrated carbonaceous mudstone (DCM) and disintegrated red-bed mudstone (DRM). Tensile strength (TS) tests under various temperature-humidity conditions, and then contact angle tests, unconfined compressive strength (UCS) tests under cyclic wet-dry conditions were carried out on PU modified disintegrated mudstone (PU-MDM). The hydrophobicity and mechanical characteristics of PU-MDM were studied. In addition, a series of microscopic tests including scanning electron microscopy (SEM), mercury intrusion porosimetry (MIP), X-ray diffraction (XRD), and fourier transform infrared spectroscopy (FTIR) were conducted to examine the curing mechanism of PU from a microscopic perspective. The results show that PU modified disintegrated carbonaceous mudstone (PU-MCM) is insensitive to temperature and high humidity when it is modified into a hydrophobic material. The TS and contact angle increase gradually with increasing PU content and component B, and they tend to be stable after the PU content and dosage ratio reach 5 wt% and 1:4, respectively. The stabilized TS is 2.42 MPa, and the corresponding contact angle is 94.84°, indicating that the material is modified to be hydrophobic. At natural temperature (30 °C), the specimen with a PU content of 5 wt% and a dosage ratio of 1: 4, the TS value can reach 77% of the maximum after curing for 1 d. PU-MDM with 5 wt% PU shows a good resistance to wet-dry cycles. After 10 wet-dry cycles, the UCS of PU-MDM is still significantly higher than that of DM specimens without wet-dry cycles. The microscopic results indicate that PU can effectively enhance the cementation of soil particles, which leads the soil structure to be denser and exhibit a certain hydrophobic effect. It is found that PU is not only environmentally friendly but also effective and fast in modifying DM.

REDUCED THE CONSUMPTION OF PROCESS WATER FOR GROWING-FINISHING YOUNG PIGS

The production of meat products requires significant direct and indirect water expenditures. Our research was aimed at improving technological methods to reduce the consumption of process water during the growing-finishing phase in young pigs. It was found that the use of technological method to reduce the consumption of process water for manure removal, which consists in reducing the level of filling baths with water in the first growing-finishing phase to 0.05 m, in the second phase - to 0.07 m, allowed to reduce the average daily water consumption by 36.8% compared to the normal operation of a self-alloying intermittent manure removal system. At the same time, the temperature-humidity conditions and gas composition of indoor air corresponded to the normative requirements.

Experimental Treatment of Hazardous Ash Waste by Microbial Consortium Aspergillus niger and Chlorella sp.: Decrease of the Ni Content and Identification of Adsorption Sites by Fourier-Transform Infrared Spectroscopy.

Despite the negative impact on the environment, incineration is one of the most commonly used methods for dealing with waste. Besides emissions, the production of ash, which usually shows several negative properties, such as a higher content of hazardous elements or strongly alkaline pH, is problematic from an environmental viewpoint as well. The subject of our paper was the assessment of biosorption of Ni from ash material by a microbial consortium of Chlorella sp. and Aspergillus niger. The solid substrate represented a fraction of particles of size <0.63 mm with a Ni content of 417 mg kg–1. We used a biomass consisting of two different organisms as the sorbent: a non-living algae culture of Chlorella sp. (an autotrophic organism) and the microscopic filamentous fungus A. niger (a heterotrophic organism) in the form of pellets. The experiments were conducted under static conditions as well as with the use of shaker (170 rpm) with different modifications: solid substrate, Chlorella sp. and pellets of A. niger; solid substrate and pellets of A. niger. The humidity-temperature conditions were also changed. Sorption took place under dry and also wet conditions (with distilled water in a volume of 30–50 ml), partially under laboratory conditions at a temperature of 25°C as well as in the exterior. The determination of the Ni content was done using inductively coupled plasma optical emission spectrometry (ICP-OES). The removal of Ni ranged from 13.61% efficiency (Chlorella sp., A. niger with the addition of 30 ml of distilled water, outdoors under static conditions after 48 h of the experiment) to 46.28% (Chlorella sp., A. niger with the addition of 30 ml of distilled water, on a shaker under laboratory conditions after 48 h of the experiment). For the purpose of analyzing the representation of functional groups in the microbial biomass and studying their interaction with the ash material, we used Fourier-transform infrared (FTIR) spectroscopy. We observed that the amount of Ni adsorbed positively correlates with absorbance in the spectral bands where we detect the vibrations of several organic functional groups. These groups include hydroxyl, aliphatic, carbonyl, carboxyl and amide structural units. The observed correlations indicate that, aside from polar and negatively charged groups, aliphatic or aromatic structures may also be involved in sorption processes due to electrostatic attraction. The correlation between absorbance and the Ni content reached a maximum in amide II band (r = 0.9; P < 0.001), where vibrations of the C=O, C–N, and N–H groups are detected. The presented results suggest that the simultaneous use of both microorganisms in biosorption represents an effective method for reducing Ni content in a solid substrate, which may be useful as a partial process for waste disposal.

Surface color changes of oak (Quercus alba L.) treated with dopamine and iron ion compounds by acceleration of temperature–humidity condition

To change the surface color of oak (Quercus alba L.) to dark and grey, the water-soluble iron ion compounded dopamine solution was applied and accelerated in temperature–humidity condition. The colorimetric parameters before and after treatment were measured and X-ray photoelectron spectra were carried out for a further understanding. The results showed that iron ions and the compounds can significantly cause color changes to the oak, while the compounds treated groups seemed more uniform. With increasing concentration of the colorants, the color change was more obvious. During acceleration in temperature–humidity condition, the oxidation occurred, which further caused color change to oak. However, different oxidation reactions might occur between iron ions and compounds treated groups. The compounds system was more sensitive to temperature–humidity condition. Thus, the color difference was the highest. In a word, this treatment was effective considering the coloring effect and safety process.

Динаміка змін об’ємів і радіаційних характеристик радіоактивно забрудненої води в об’єкті «Укриття» в умовах нового безпечного конфайнмента

In November 2016 the “Arch” of the New Safe Confinement (NSC) was installed into design position over the Shelter object (SO). Installation of the NSC in design position stipulated the changes of the mode of water inflow into underroof space of the SO. The conditions of the SO rooms ventilation as well as temperature-humidity conditions have changed inside the SO. It resulted in the considerable changes of formations conditions of the radioactively contaminated water (RCW) unorganized accumulations in the complex NSC–SO rooms. Aim of the work is to study the dynamics of changes of RCW volumes, concentration of uranium, macrocomponets, as well as radionuclides activity concentration in the RCW unorganized accumulations in rooms at the bottom marks of the SO under conditions of the NSC operation for 2017−2020. Experimental data on the determination of the volumes and radiation characteristics of radioactively contaminated water in unorganized accumulations of liquid radioactive waste at the bottom marks of the SO after the NSC installation into the design position are presented. The biggest accumulations of RCW are in the room 001/3 at the mark −2.60 m. Volume of the accumulation is approximately 270 m3. During the last decade a water level at the control point is about 1.1 m and does not change practically. During December 2016 – June 2020 the volume of radioactively contaminated water in rooms 017/2, 012/5–8 and 012/13–16 decreased by more than 10 times. In rooms 009/4, 013/2, 014/2 and 210/5–7, the water has dried completely. A decrease of radioactively contaminated water volume occurs due to the evaporation of water during the autumn-winter seasons and is not compensated by the formation of condensation moisture in the summer. Due to the water evaporation, concentrations of macrocomponents and uranium, as well as the activity concentration of radionuclides 90Sr, 137Cs, 154,155Eu, 238,239,240Pu, 241Am and 244Cm in the radioactively contaminated water increased significantly. The activity concentrations of radionuclides are 90Sr — n ∙ 109, 137Cs — n ∙ 1010, 154Eu – n ∙ 106, 239 + 240Pu – n ∙ 106, 241Am — n ∙ 107, 244Cm — n ∙ 105 Bq/m3. As a result of drying out of radioactively contaminated water accumulations, highly active deposits are formed, which are a source of radioactive aerosols in the rooms of the SO. During water evaporation there is an increase of RCW alkaline, рН increases to the values of 9.5–10.2. It is due to the increase of concentration of carbonates of CO3 2– and hydro carbonates of HCO3 – in water.

Precipitation structure as an indicator of reduction of water amount supplying soil profile

The objective of this study was the estimation of the effect of droplet structure of diurnal precipitation totals, measured with Thies Clima disdrometer, on the value of surface runoff from three kinds of surface used in urban areas, i.e. a roof surface covered with small-grain roofing paper, a car park surface of openwork concrete slabs, and a tarmac surface, and the resultant reduction of infiltration from atmospheric precipitation. The detailed comparative analysis of diurnal precipitation totals in the aspect of droplet structure, structure of increasing influx of precipitation water to the surface, and changes of air temperature-humidity conditions, allowed preliminary elucidation of the effect of those factors on the values of the runoff indices for the different hardened surfaces. The analysis of reduction of infiltration presents the level of supply losses resulting from the use of surface covering systems with various degrees of permeability to precipitation water. A solution that can minimise the indicated losses can be an approach to precipitation water management assuming interception of possibly the largest amounts of non-productive surface runoff waters, and then using that water.

Wintering ability ofCalophoma complanataunder the conditions of Saint Petersburg area

Giant hogweed is one of the most widespread invasive alien species of the Baltic region. The pycnidial fungus,Calophoma complanatais being evaluated as a potential bioherbicide for control ofHeracleum sosnowskyi. The aim of this work is to evaluate an ability of the potential mycoherbicideC.complanataMF-32.121 to overwinter in the conditions of Saint Petersburg area. Plants inoculated byC. complanataMF-32.121 successfully survives wintering in the conditions of Saint Petersburg area. Pearl barley covered byC. complanataMF-32.121 mycelium successfully survives wintering in the same conditions as well. When favorable conditions have arisen, theC. complanataMF-32.121 mycelium is capable to infecting young giant hogweed. Moreover, it was revealed that a change in the biochemical composition, namely, an increase in the level of trehalose, contributes to the manifestation of a greater tolerance ofC. complanataMF-32.121 mycelium to temperature-humidity conditions.

CLIMATE CHANGE IN THE LOW DNIESTER BASIN AS A FACTOR OF IMPACTS ON WATER ECOSYSTEMS

Problem. Obviously, the biotic composition, structure and function of freshwater ecosystems depend largely on the climatic conditions in a river basin. This dependence becomes more complicated in the context of global warming, when the centuries-old relative climate stability, or its stationarity, disappears, and the more and more increasing changes in climate are observed. Aim. The aim of the present research was to compare statistically temperature-humidity conditions in the Low Dniester basin in two periods (1961-1990 and 1991-2018) that respectively characterize different climatic thirty-years according to the WMO classification.Methods. For each period, the average annual and seasonal values of key climatic variables - air temperature and precipitation - as well as their linear trends were considered. As initial information, the observations at weather stations of Moldova, located in this part of the Dniester basin, were takenResults. The analysis showed that in the second periods the annual mean (Tmean), maximal (Tmax) and minimal (Tmin) temperatures have increased in absolute terms by 1.0, 1.8 and 0.7°C, respectively. With regard to seasonal temperatures, the highest Tmean increase was observed in summer (1.6°C), the smallest – in autumn (0.4°C). Tmax increased mostly in winter (by 3.1°C), and to a lesser extent – in autumn (by 0.6°C). The greatest increase in Tmin was observed in winter (1.7°C), the smallest – in spring (0.2°C). At the same time, the total change of precipitation was extremely small: only 6 mm decrease per year. A slight increase in precipitation (by 25 mm) was noted only in the autumn months. The analysis of linear trends confirmed the results of a comparative analysis. Negative air temperature trends in 1961-1990, with the exception of a slight positive one for Tmax, have changed to their positive values for all parameters in the last three decades. In particular, during this period the increase in mean air temperature was 0.6°C per decade. The slight negative trend of precipitation (~2 mm/year) in 1961-1990 was replaced by their negligible increase (~0.5 mm/year).Conclusion. An increase in air temperature, which is not compensated by an increase in precipitation, is inevitably accompanied by an increase in the climate aridity, already characteristic for the northern Black Sea coast, which negatively affects the existence and development of aquatic and terrestrial ecosystems in this region.

RISK ANALYSIS AND IDENTIFICATION OF CRITICAL CONTROL POINTS (CCP) IN PRODUCTION OF NATURAL INTESTINAL CASINGS

Implementation of the HACCP system in enterprises manufacturing natural intestinal casings is topical for ensuring high quality and confidence in safety of manufactured products. The paper examines hazardous factors in production of natural intestinal casings, analyzes risks with assessment of the probability of hazardous factor occurrence. To this end, a Pareto chart was constructed, unacceptable risks were determined, CCPs were revealed using the decision tree, critical control limits were established for each CCP and the requirements for their monitoring were specified. In addition, the paper gives risk analysis for the stage «salting» with expert assessment of the severity of consequences from realization of a certain hazardous factor and the probability of this realization for each risk. The risk of microbial growth due to addition of the insufficient amount of salt was classified as a biological factor with the severity of consequences 3 and the probability of realization 3. The risk of microbial growth due to violation of the temperature-humidity conditions and duration of holding on a site is also a biological factor with the severity of consequences 3 and the probability of realization 2. These stages are assigned to CCPs. Using the Pareto chart, the factors that had the highest effect on safety and quality of natural intestinal casings were grouped; with that, the percentage ratio of the revealed hazardous factors was established: biological/chemical/physical/allergens 65/20/15/0 for the whole technological process.

Research of the Stress-Strain State of Glued Wooden Structures After Prolonged use in Various Extreme Conditions

Glued wooden structures for example beams, frames, archs had been used in the territory of the Arkhangelsk region in the period since the 70s to the 90s years of the XX century for the purpose of industrial and agricultural assignment as load-bearing structures of the coating. Today their age is 30-40 years. Such a period of time makes it possible to evaluate the technical condition of structures from the point of view of durability and to identify the main errors and shortcomings when design, construction and operation of glued wooden structures. The article presents the results of the survey of wooden glued structures coatings for various purposes: Ice rink, swimming pool, production hall with challenging temperature-humidity conditions. The survey was identified damage in beams in the form of degradation of the wood due to lesions wood-destroying mushrooms, longitudinal cracks in the glue seam, and damage by fire. In most cases, the cause of damage is the improper operation of buildings. Are most common damage have been identified longitudinal cracks in glue lines. Influence of cracks on the stress-strain state of glued wooden structures is addressed. The method for solving a problem of accounting for disbonds in a glued wooden structures is invited.

Providing thermal protection when replacing window blocks in historical buildings

The work presents the prerequisites to replace the window units in the historical buildings (primarily increased energy efficiency standards of buildings and significantly changed performance requirements of window units). The analysis of possible replacement options (full/partial) of window units of the historical buildings is done according to their architectural and historical values. A review is made of the existing technological capabilities of modern window systems and translucent filling (double-glazed windows), as well as the most common solutions used in practice. The issue of providing the temperature-humidity conditions of the nodes of adjunctions of the window blocks to the openings of the external walls in the winter operating conditions is considered. For this purpose, a numerical simulation of the temperature fields of the junction points is made for various structural embodiments of window frames. It is established that in the case of a full replacement of window blocks and maintaining the existing structure of external walls (the calculation is made using the example of the most common external wall for Central Russia – a brick wall 770 mm thick), condensation may form on the inner surface of window slopes. Different options are suggested for window blocks installation, which ensure the fulfillment of sanitary and hygienic requirements. Further directions for the research on the use of modern types of translucent structures in the historical buildings are outlined.

Constraining the Potential Liquid Water Environment at Gale Crater, Mars.

The Mars Science Laboratory (MSL) Rover Environmental Monitoring Station (REMS) has now made continuous in situ meteorological measurements for several Martian years at Gale crater, Mars. Of importance in the search for liquid formation are REMS' measurements of ground temperature and in-air measurements of temperature and relative humidity, which is with respect to ice. Such data can constrain the surface and subsurface stability of brines. Here we use updated calibrations to REMS data and consistent relative humidity comparisons (i.e., with respect to liquid versus with respect to ice) to investigate the potential formation of surface and subsurface liquids throughout MSL's traverse. We specifically study the potential for the deliquescence of calcium perchlorate. Our data analysis suggests that surface brine formation is not favored within the first 1648 sols as there are only two times (sols 1232 and 1311) when humidity-temperature conditions were within error consistent with a liquid phase. On the other hand, modeling of the subsurface environment would support brine production in the shallow subsurface. Indeed, we find that the shallow subsurface for terrains with low thermal inertia (Γ ≲ 300 J m-2 K-1 s-1/2) may be occasionally favorable to brine formation through deliquescence. Terrains with Γ ≲ 175 J m-2 K-1 s-1/2 and albedos of ≳0.25 are the most apt to subsurface brine formation. Should brines form, they would occur around Ls 100°. Their predicted properties would not meet the Special nor Uncertain Region requirements, as such they would not be potential habitable environments to life as we know it.

Comparison of Selected Properties of Shellac Varnish for Restoration and Polyurethane Varnish for Reconstruction of Historical Artefacts

At present, many historical artefacts and furniture are only reconstructed and not restored. They are preserved in terms of material reparation, but their historical value decreases significantly. This work is focused on the comparison of the resistance of high-gloss polyurethane varnish with traditional shellac varnish. The varnishes were applied to oak wood and exposed to interior artificial accelerated ageing in Xenotest. Before and after ageing, cold liquid-resistance tests were performed on the tested specimens and gloss, colour, and adhesion were also evaluated. The structures of the surfaces were also analysed using a confocal laser scanning microscope. As expected, polyurethane varnish was much more durable than shellac varnish. Interestingly, shellac varnish was fairly resistant to water at the beginning, but this resistance was greatly reduced after artificial accelerated ageing. This illustrates the importance of sheltering the shellac treated artefacts in stable temperature-humidity conditions with the least possible effect of solar radiation.

A ‘heart rate’-based model (PHSHR) for predicting personal heat stress in dynamic working environments

The parameter of human body metabolic rates has been popularly used for the prediction of human heat stress in hot environments. However, most modules use the fixed and estimated metabolic heat production. The aim of this study is to develop the prediction of personal heat stress in dynamic working environments. Based on the framework of the predicted heat stress (PHS) model in ISO 7933, a heart rate-based PHSHR model has been developed using the time-based heart rate index, which is suitable for prediction in situations where metabolic rates are dynamic and there are inter-individual variations. The infinitesimal time unit Δti, has been introduced into the new PHSHR model and all the terms used in the PHS model related to metabolic rates are thus redefined as the function of real-time heart rates. The PHSHR has been validated under 8 experimental combined temperature-humidity conditions in a well-controlled climate chamber. The feature of the PHSHR model is being able to calculate dynamic changes in body metabolism with exposure time. It will be useful to the identification of potential risks of individual workers so to establish an occupational working environment health and safety protection mechanism by means of simultaneous monitoring of workers' heart rates at the personal levels, using advanced sensor technology.