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This study aims to propose a new design value, based on experimental and numerical studies, for surface emissivity of zinc hot-dip galvanized members exposed to fire.

The paper sums up experiments, used specimens and also shows results. Four experiments were performed in a horizontal furnace and one test in a fire compartment of the experimental building. Several tests were carried out for determination of the surface emissivity of galvanized steel structures in fire. The experimental and numerical studies were used for preparation of new generation of the structural steel fire standard Eurocode EN 1993-1-2:2025.

Hot-dip galvanizing is one of the most widely used processes for corrosion protection of steel products. The new design value for surface emissivity of zinc hot-dip galvanized members exposed to fire is determined using experimental results as 0.35. The value is proposed for next generation of EN 1993-1-2:2025. If hot-dip galvanization additionally can contribute beneficially to the fire resistance of unprotected steel members, it would be a huge economic advantage.

Experimental studies in the past years have indicated the influence of hot-dip galvanizing on the heating of steel members. This study suggests 50% reduction of the surface emissivity of a carbon steel member. This amendment will be incorporated in future versions of Eurocodes 3 and 4 and has already been implemented in some fire design tools for steel members in order to consider the beneficial contribution of hot-dip galvanized for fire-resistance requirements of less than 60 min.

Great savings can be achieved by detecting and isolating design problems early in an electronic programme. Many design problems, including electrical overstress, poor thermal design and circuit layout problems, are detectable by their infrared (I‐R) signature. A reliability and design improvement tool utilising current I‐R scanning technology has been developed. Specifically, an I‐R scanning method for making accurate temperature measurements for the purpose of electronic design reliability improvement and qualification has been developed and verified experimentally. Field‐actual conditions, in which radiative and convective heat losses from the components are negligible, are simulated with a thermally insulating enclosure. The enclosure is designed for rapid removal just before the scan, obviating the need for exotic materials that are transparent to I‐R in the scanner's passband. With typical hardware thermal lags, the method allows determination of true temperatures simulating field conditions. Corrections for unwanted scanner‐produced radiation and for the target emissivity are made with a three‐scan method and specially designed apparatus. An integral part of this apparatus is the aforementioned quickly removable thermal enclosure. The three scans take approximately an hour for a typical circuit board after initial set‐up time. True‐temperature measurements of circuit boards can be made with the I‐R design improvement tool now.

In this paper, temperature distribution and fin efficiency in a moving porous fin have been discussed. The heat transfer equation is formulated by using Darcy's model. Heat transfer coefficient and thermal conductivity vary with temperature. The surface emissivity of the fin varies with temperature as well as with wavelength. Thermal conductivity is taken as a linear and quadratic form of temperature. The entire analysis of the paper is presented in non-dimensional form.

In this study, a new mathematical model is investigated. The novelty of this model is surface emissivity which is considered temperature and wavelength dependent. Another interesting point is the addition of porous material. The Legendre wavelet collocation method has been used to solve the nonlinear heat transfer equation. Numerical simulations are carried out in MATLAB software.

An attempt has been made to discuss temperature distribution in the presence of porosity and wavelength-temperature-dependent surface emissivity. The effect of various parameters on temperature has been discussed, including thermal conductivity, emissivity, convection-radiation, Peclet number, sink temperature, exponent “n” and porosity. Fin efficiency is also calculated for some parameters. According to the study, heat transfer rate increases with higher radiation-convection, emissivity, wavelength and porosity parameters.

The numerical results are carried out by using the Legendre wavelet collocation method, which has been compared with exact results in a particular case and found to be in good agreement. The percent error is calculated to find the error between the current method and the exact result. A comparison of the obtained results with the previous data is presented to validate the numerical results.

The purpose of this paper is to calibrate the surface emissivity of micro drill bit and to investigate the effect of different drilling parameters on the temperature of micro drill bit in printed circuit board (PCB) micro drilling process.

The surface emissivity of micro drill bit was obtained by experiments. Analysis of variance (ANOVA) was applied in this study to analysis the effect of different drilling parameters on the temperature of micro drill bit in PCB micro hole drilling. The most significant influencing factor on micro drill bit temperature was achieved by ANOVA.

First, the surface emissivity of cemented carbide rod decreased from 0.4 to 0.32 slowly with temperature in the range of 50-220°C. Second, the most significant influencing factor on the micro drill bit temperature was spindle speed among the drilling parameters including spindle speed, retract rate and infeed rate.

In this paper, the influence of roughness of black coating, carbide rod and micro drill bit on the surface emissivity calibration and the temperature measurement was not considered.

A new simple method has been presented to calibrate the surface emissivity of micro drill bit. Through calibrating the surface emissivity of micro drill bit, the temperature of micro drill bit can be measured accurately by infrared thermometry. Analyzing the influences of different drilling parameters on the temperature of micro drill bit, the mechanism of drilling parameters on drilling temperature is achieved. The basis for the selection of drilling parameters to improve the hole quality is enhanced.

Based on the advantages of conventional hot-dip galvanizing made from quasi-pure zinc melts in the event of fire, this article aims to perform a series of tests to verify whether a similar effect can be achieved with zinc-aluminum coatings.

The emissivity of galvanized surfaces, which were applied to steel specimens by the batch hot-dip galvanizing process, was experimentally determined under continuously increasing temperature load. In addition to a quasi-pure zinc melt serving as a reference, a zinc melt alloyed with 500 ppm aluminum and thin-film galvanized with a melt of zinc and 5% aluminum were used. For the latter, variants of post-treatment measures in terms of a passivation and sealing of the galvanizing were also investigated.

The results show that lower emissivity can be achieved at higher temperatures by adding aluminum to the zinc melt and thereby into the zinc coating. The design values required for the structural fire design were proposed, and an exemplary calculation of the temperature development in the case of fire was carried out based on the values. The result of this calculation indicates that the savings potential becomes apparent, when using zinc-aluminum coatings.

The presented novel tests describe the behavior of zinc-aluminum coatings under the influence of elevated temperatures and their positive effect on the emissivity of steel components galvanized by this method. The results provide valuable insights and information on the performance in the event of fire and the associated potential savings for steel construction.

The purpose of this paper is to investigate the heat transfer on an alpine‐climbing mitt featuring an electrical heating multilayer, in order to provide information for the optimization of its thermal performance.

A numerical model was developed to simulate the heat transfer across an electrical‐heated alpine mitt. The model was used to study the heat losses as a function of the environmental conditions, to optimise the positioning of the heating elements, to determine the optimal power input to the heating system, to estimate the battery capacity requirements and to assess the effect of low‐emissivity surfaces.

The results show that: the heating elements assure approximately constant temperatures across the skin provided they are not more than 6‐7 mm apart; the use of low‐emissivity surfaces facing the skin can reduce the total heat loss by 8‐36 per cent (for air layer thicknesses in the range 10⁻³ to 10⁻² m) and to increase the skin temperature during the transient operation of the heating multilayer; the heat losses from the mitt are practically independent of the chosen heating power; and a battery capacity of 4 A h assures active temperature regulation for more than 18‐23 h.

By enhancing the thermal performance of an electrical heating mitt, the use of low‐emissivity surfaces (facing the skin) can favour the thermal comfort perception of its user.

The influence of several parameters on the thermal performance of an electrical‐heated mitt is analysed and discussed. The findings are relevant for improving the performance of existing electrical heating garments.

This purpose of this paper is to report about the temperature distribution in metal and ceramic powder beds during 3D printing. The differing powders are thoroughly characterized in terms of thermal conductivity, thermal diffusivity, emissivity spectra and density.

The temperature distribution was measured in a 3D printing appliance (Prometal R1) with the help of thin thermocouples (0.25 mm diameter) and thermographic imaging. Temperatures at the powder bed surface as well as at differing powder bed depths were determined. The thermal conductivity, thermal diffusivity and emissivity spectra of the powders were measured as well. Numerical simulation was used to verify the measured temperatures.

The ceramic powder heated up and cooled down more quickly. This finding corresponds well with numerical simulations based on measured values for thermal conductivity and thermal diffusivity as well as emissivity spectra. An observed color change at the metal powder has only little effect on emissivity in the relevant wavelength region.

It was found that thermocouple‐based temperature measurements at the powder bed surface are difficult and these results should be considered with caution.

The results give practitioners valuable information about the transient temperature evolution for two widely used but differing powder systems (metal, ceramic). The paramount importance of powder bed porosity for thermal conductivity was verified. Already small differences in thermal conductivity, thermal diffusivity and hence volumetric heat capacity lead to marked differences in the transient temperature evolution.

The paper combines several techniques such as temperature measurements, spectral emissivity measurements, measurements of thermal conductivity and diffusivity and density measurements. The obtained results are put into a numerical model to check the obtained temperature data and the other measured values for consistency. This approach illustrates that determinations of surface temperatures of the powder beds are difficult.

The purpose of this paper is to study the thermal behaviour of a fully wet porous fin of longitudinal profile. The significance of radiative and convective heat transfer has been scrutinised along with the simultaneous variation of surface emissivity, heat transfer coefficient and thermal conductivity with temperature. The emissivity of the surface and the thermal conductivity are considered as linear functions of the local temperature between fin and the ambient. Darcy’s model was considered to formulate the heat transfer equation. According to this, the porous fin permits the flow to penetrate through it and solid–fluid interaction occurs.

Runge–Kutta–Fehlberg fourth–fifth-order method has been used to solve the reduced non-dimensionalized ordinary differential equation involving highly nonlinear terms.

The impact of pertinent parameters, such as convective parameter, radiative parameter, conductivity parameter, emissivity parameter, wet porous parameter, etc., on the temperature profiles were elaborated mathematically with the plotted graphs. The heat transfer from the fin enhances with the rise in convective parameter.

The wet nature of the fin enhances heat transfer and in many practical applications the parameters, such as thermal conductivity, heat transfer coefficient as well as surface emissivity, vary with temperature. Hence, the main objective of the current study is to depict the significance of simultaneous variation in surface emissivity, heat transfer coefficient and thermal conductivity with respect to temperature under natural convection and radiation condition in a totally wetted longitudinal porous fin.

Based on the known positive effects of conventional hot-dip galvanizing under fire exposure and indicative results on zinc–aluminum coatings from smallscale tests, a series of tests were conducted on zinc-5% aluminum galvanized test specimens under fire loads to verify the previous positive findings under largescale boundary conditions.

The emissivity of zinc-5% aluminum galvanized surfaces applied to steel specimens was determined experimentally under real fire loads and laboratory thermal loads in accordance with the normative specifications of the standard fire curve. Both large and smallscale specimens were used in this study. The steel grade and surface conditions of the specimens were varied for both test scenarios.

Largescale tests on specimens with typical steel construction dimensions under fire loads showed that the surface emissivity of zinc-5% aluminum galvanized steel was significantly lower than that of the conventionally galvanized steel. Only minor influences from the weathering of the specimens and steel chemistry were observed. These results agree well with those obtained from smallscale tests. The design values of zinc-5% aluminum melt (Zn5Al) required for the structural fire design were proposed based on the obtained results.

The novel tests presented in this study are the first ones to study the behavior of zinc-5% aluminum galvanized largescale steel construction components under the influence of real fire exposure and their positive effect on the emissivity of steel components galvanized by this method. The results provide valuable insights and information on the behavior in the case of fire and the associated savings potential for steel construction.

In order to study whether far-infrared fabrics can be used as a garment for breast cancer patients, or as an adjuvant rehabilitation underwear for breast cancer patients after postoperative radiotherapy and chemotherapy, to eliminate tissue edema. To explore the effect of different far-infrared fabrics on the proliferation and invasion of breast cancer cells as a basic in vitro study.

Six kinds of fabrics of the same specification with different far-infrared nanoparticles were selected. MCF7 and Bcap37 breast cancer cells were used to study the effect of far-infrared fabrics on cell proliferation and invasion. Six kinds of far-infrared fabrics were used to culture breast cancer cells and explore their effects on breast cancer cell growth and the difference between different far-infrared fabrics.

It is found that the far-infrared emissivity of six kinds of fabrics are different, among which tea carbon fabric is the highest, followed by volcanic fabric, graphene fabric and biomass graphene fabric are the lowest. The results show that the far-infrared fabrics can significantly inhibit the proliferation and invasion of breast cancer cells, the higher the far-infrared emissivity is, and the longer the time of far-infrared radiation, the more significant the inhibition effect is.

Far-infrared fabrics can inhibit proliferation and invasion of breast cancer cells in vitro. Therefore, far-infrared fabrics can be used for adjuvant rehabilitation of breast cancer patients. This conclusion provides a basis for the application of far-infrared functional fabrics in the medical field. This conclusion provides a basis for the application of far-infrared functional fabrics in medical field.