Low Emissivity Materials Research Articles

An Investigation and Benchmarking Model for Developing Sustainable Material Use Among Turkish Airport Operators

Sustainable material use refers to the capacity of a material to be utilized in a way that does not deplete the Earth’s natural resources or harm the ecosystem. This lowering might entail employing renewable or recyclable materials and reducing the overall quantity of material utilized in airport services. Renewable materials, recyclable materials, biodegradable materials, reusable materials, low-impact materials (low-emission materials), natural materials, and non-toxic materials are sustainable materials used in airports. There are 58 civil airports operated in Turkiye. The public information on the airport operators’ websites can assess sustainable material use in these airports. Mentioned 58 airports are operated under ten different airport groups. This study offered a novel scoring system called CACS which stands for Clarity, Accessibility, Continuity, and Suitability, to retrieve sustainable material use from sustainability reports of airport operators. The model proposed in this paper will help the readers benchmark a group of airports not present in the literature. The results show that İGA airport is the highest score among the ten airports, followed by TAV airports at 820.6 and 256.3, respectively. The top five airports encapsulate 97.44% after the Normalization of passenger counts of Turkiye. Airport operators’ sustainable material usage and other sustainability benchmarking on numerous domains based on sustainability reporting systems would draw the public and increase awareness, allowing operator firms and airport authorities to concentrate on creating a more livable future.

Analysis and Study of credits for IGBC Green New Building

The green building movement in India has gained significant momentum with over 8,669 registered projects under the Indian Green Building Council. The LEED standards influence the design and construction of environmentally sustainable structures with a focus on resource conservation, waste reduction, and creating healthy spaces. The IGBC criteria encompasses aspects such as sustainable architecture and design, site selection, energy and water conservation, building materials, indoor environmental quality, and innovation. Energy efficiency and water conservation are emphasized through eco-friendly refrigerants, renewable energy sources, and water-wise practices. The use of certified green building materials, products, and equipment helps reduce environmental impact. Indoor environmental quality is maintained through adequate ventilation, low-emitting materials, and indoor air quality testing. Building owners and contractors can employ various strategies to improve the well-being of occupants. Key Words: Green building, Sustainable, Conservation, Environment, Eco-friendly, Renewable

LEED-CI v4 Projects in Terms of Life Cycle Assessment in Manhattan, New York City: A Case Study

Over the last decade, it has been clearly shown that the same achievements in Leadership in Energy and Environmental Design (LEED) projects can lead to different life cycle assessments (LCAs). However, the problem of contradictory achievements in LEED and LCA has not yet been resolved. This study aimed to identify and evaluate different strategies for LEED projects using LCAs. Thirty-nine LEED projects with the same characteristics—location and transportation, rating system, rating version, certification level, and space type—were collected and sorted by their energy and atmosphere (EA) category, “optimize energy performance” credit (EAc6) achievement into three equal groups (EALow, EAMedium, and EAHigh, where each group includes 13 LEED projects) to minimize the influence of uncontrolled factors on the LEED project strategy. The author focused on two extreme groups with very different EAc6 credit scores: EALow (13 projects) and EAHigh (13 projects). The groups were compared across LEED categories and credits. Wilcoxon–Mann–Whitney and Cliff’s δ test results showed that the EALow and EAHigh groups are associated with high/low achievements in materials-related credits such as “interiors life cycle impact reduction”, “building product disclosure and optimization—material ingredients”, and “low-emitting materials”. As a result, the EALow and EAHigh groups were reclassified into EnergyLow–MaterialsHigh and Energyhigh–MaterialsLow certification strategy groups. In this context, LCAs were used to assess the differences between the two strategies. The results showed that if natural gas was used for operational energy (OE), the EnergyHigh–MaterialsLow strategy showed lower environmental damage compared to the EnergyLow–MaterialsHigh strategy (p = 0.0635); meanwhile, if photovoltaic energy was used for OE, the EnergyLow–MaterialsHigh strategy showed lower environmental damage compared to the EnergyHigh–MaterialsLow strategy (p = 0.0036). The author recommends using the LEED protocol and the LCA method in parallel to better reflect the environmental impact of different certification strategies.

BIM-based approach for the integrated assessment of life cycle carbon emission intensity and life cycle costs

The construction industry is well known for generating a large amount of carbon emissions and this, together with huge costs of buildings during their life cycle, seriously affects its environmental and economic sustainability. That reducing the former tends to increase the latter is a highly significant problem exacerbating the situation. Finding a solution with the lowest carbon emission at a certain cost is an urgent problem to be solved. Research to date aimed at remedying the situation, however, has been largely focused on either treating the two issues independently or partially conjoined, with little progress in their integrated assessment. In response, this study presents a method for integrating the life cycle carbon emissions (LCCE) and life cycle costs (LCC) of buildings to assess their life cycle carbon emission intensity (CEI) based on BIM technology. Through a public building in China as a case study, the feasibility of the method is verified, the key stages of building carbon emissions are analyzed using CEI, and the conversion of high carbon emission materials to low carbon emission materials is explored. The proposed methodology and framework provide solutions and ideas for achieving optimal costs commensurate with low carbon emissions throughout the building life cycle, facilitating the assessment of carbon emissions at the decision-making and design stages, achieving the optimization of building carbon emissions and costs, and enhancing building life cycle sustainability.

The impact of modeling assumptions on retrofit decision-making for low-carbon buildings

To reach decarbonization goals, effective and robust building retrofit decisions are critical. Environmental retrofit assessments rely on full or partial life cycle assessments, which require several modeling assumptions. However, the currently typical ‘status quo’ modeling assumptions for assessing building retrofits need to be questioned with an increasing state of climate emergency. We identify and study the impact of five relevant modeling assumptions that potentially influence the effectiveness of building retrofit: (i) the environmental allocation of photovoltaic electricity, (ii) the effect of global warming, (iii) decarbonization pathways, (iv) choice of the analysis period, and (v) the allocation of biogenic carbon stored in building materials. To investigate the impact of modeling assumptions on the environmental performance and the robustness of retrofit decisions, we establish a framework to compare calculated GHG emissions under different modeling assumptions. The framework is applied to a typical Swiss building. The results show that the choice of modeling assumptions can indeed affect retrofit decision-making based on GHG emissions. In particular, grid decarbonization assumptions strongly impact the choice of renovation strategies. Similarly, the allocation method of locally produced renewable electricity can be decisive when investigating the installation of photovoltaic systems. Aligning the analysis period with the urgency of global warming mitigation shifts the focus towards the embodied emissions, favoring low-emission materials. In contrast, assumptions on global warming do not majorly affect the retrofit decision for the example building. Overall, the introduced approach leads to a more comprehensive view on building retrofit robustness, allowing decision-makers to make better-informed retrofit decisions.

Numerical simulation and analysis of wall temperature based on the tangent oval model under different speed and radiation conditions

In this paper, the influence mechanism of flight speed, altitude and emissivity of skin material on the temperature of aircraft wall were systematically analysed by numerical simulation. The results show that the increase of the velocity would lead to the rise of the wall pressure and temperature of the aircraft. In addition, a speed of 5 Ma and flight altitude at 30 km, the heat transmitted to the outside was reduced with the decrease of skin material emission. As a result, the constant increase of its own heat energy, which led to the continuous rise of the wall temperature of the aircraft. And the total target radiation emission was reduced by 58.8% with the decrease of emissivity (from 0.8 to 0.2). These results show that the infrared radiation of the aircraft could effectively be suppressed by low emissivity material, the infrared stealth performance of aircraft was enhanced. The research has guiding significance for the temperature-resistant characteristics of skin materials and infrared radiation control.

Analysis on Infrared Stealth Performance of Metal Nano-coating on Radome Surface

Infrared stealth technology used in aircraft is applied to reduce the infrared signal by controlling surface temperature and emissivity using internal heat sink, low emissivity material or metamaterial. However, there is one part of the aircraft where the use of this technology is limited, and that is the radome. Especially, radome should have transmittance for the specific radio frequency, therefore, common stealth technology such as emissivity control surfaces cannot be applied to radome surface. In this study, we developed metal nano-coating for infrared stealth which is applicable to radome surface. We designed slot-type pattern for frequency selective transmission in X-band, and also controlled thickness of metal nano-coating for long wavelength infrared emissivity control. As a result, our infrared stealth surface for radome has 93.2 % transmittance in X-band and various infrared emissivities from 0.17 to 0.57 according to nano-coatings thickness. Also, we analyzed infrared signature of radome through numerical simulation, and finally reduced contrast radiant intensity by 97.57 % compared to polyurethane surface.

Numerical study of heat losses of building walls containing reflective foils

In external building walls, air cavities are occasionally used to reduce heat losses. Closed air cavities improve the thermal resistance of building structures, especially when the inner surfaces of the cavities are covered with low-emissivity materials such as metalized foils. With these structures, the problem of accurate determination of radiative heat arises. In this contribution, radiative heat transfer is determined by the precise algebraic radiosity method, so far not applied in the field of thermal building technology. Radiative heat computed by the radiosity method has been coupled with convective heat evaluated by the correlation functions of the Nusselt numbers. The combined radiative-convective heat transfer through a sandwich wall containing an air cavity with metalized surfaces (aluminium foils) has been analysed. A computer program has been developed to quantify the real insulation effect of reflective aluminium foils. The sandwich building structure has been subjected to real one-month winter conditions as defined by official meteorological data valid for the city of Brno. The software is based on an iterative procedure that solves the combined radiative-convective steady heat transfers by means of one-day average temperatures and wind speeds. Various arrangements of foils in the cavity have been explored to achieve the maximum value of thermal resistance. The corresponding heat savings have been quantified. The best configuration of foils in the cavity has been found to ensure maximum thermal savings. The insulation system that uses foils has been compared to the system that uses mineral wool. The comparison was based on economic considerations.

Radiation heating test and development of porous MgAl2O4 ceramics with high thermal shielding effect based on Mie theory

AbstractPorous MgAl2O4 ceramics designated as THERMOSCATTTM have diffuse reflectance based on the Mie theory. The reflectance greatly suppresses radiation heat transfer and has low emissivity at 1–5 μm wavelengths. Their thermal conductivity has been measured as less than 0.3 W/(m K) at 1500°C. Furthermore, porous MgAl2O4 ceramics have near‐zero hemispherical spectral emissivity values at 0.35–5 μm wavelengths. High heat resistance and low emissivity materials in the atmosphere are useful for the innermost layer of industrial furnaces to confine energy efficiently. Additionally, this material is useful as a radiation reflectors, such as in stand‐off thermal protection systems. This study elucidated the suppression of radiation transfer in porous MgAl2O4 ceramics attributable to low thermal emissivity. Therefore, the thermal insulation performance under radiation heating in vacuum, the emissivity validity evaluation of low‐emissivity porous materials using finite element analysis, and microstructure effects on radiation heating performance and mechanical properties were investigated.

Study of Polymer Binders to Develop Low Emissive Paints for Thermal Radiation Management Applications

The management of thermal emittance always possess challenges in both military and civil domains. The low emissive materials in form of paints offers viable solution for minimising thermal emittance of military objects for camouflage and enhancing infrared reflectivity of roof to reduce cooling loads. Binder apart from pigments is one of the critical components of low emissive paint formulation to decide its ultimate performance. For selection of appropriate resin and binder, a comparative study of five prevalent polymers viz. polyurethane (PU), poly vinyl chloride (PVC), polyethylene (PE), polypropylene (PP) and poly methyl methacrylate (PMMA) has been carried out. Polymeric film of thickness 100μm of each of the polymer is prepared by Elcometer 4340 motorized film applicator. Infrared spectra and thermogravimetric profile have been obtained by Bruker make Tensor 27 FTIR in spectral range 4000 – 600 cm-1 and TGA Q 500. Film formation of PU is excellent and transmission in 3-5 μm is almost 100%. Hence, it may be chosen as binder in low emissive paint for MWIR band. PVC and PMMA among the polymers offer excellent transmission 87-99% in both thermal transmission windows 3-5 μm and 8-12 μm. Thermogravimetric (TG) profile of polymer films evident of thermal stability of PVC, PMMA and PU polymers up to 200 °C. Infrared transmission, TG profile and film formability manifest that both binders- PVC and PMMA are suitable for development of low emissive paints applicable up to temperature 200 °C for both IR transmission windows to evade thermal detectors working for detection of military objects and reducing cooling load in buildings by enhancing reflectivity of roof by application of low emissive paint.

Assessing cooling loads from roofs with attics: Modeling versus field experiments

The use of low-emissivity materials in roofing offers a low-cost solution to reduce the demand for cooling in countries with hot climates. The performance of radiant barriers is often evaluated through simulations and the type of modeling employed influences the results. This study evaluates different modeling approaches to simulate radiant barriers in attics. First, the influence of the temperature and emissivity of materials on the thermal resistance of air chambers were evaluated. Then, the heat flow and thermal load values were obtained with the simulation of three different models. Simulation results were compared with actual tests and results in the literature. The emissivity of the materials resulted in strength variations of up to 4%. The simulation model that adopted the energy management system (EMS) and thermal resistance calculated according to ISO 6946 2017 was the closest results to experimental tests and literature. These provide maximum differences of 7% in the downward heat flow and thermal load. The model that included the attic underestimated by 20% the reduction in heat flow compared to bench tests. Finally, thermal resistance values to be adopted in attic simulations with low-emissivity materials in hot climates are proposed.

The Application of Building Information Modelling Method for Carbon Emission Analysis: A Case Study of Housing in Peat Lands

The construction sector is the largest contributor to carbon emission, especially from housing development activities, which has been on high demand due to the continuous increase in the population. This study aims to analyze the amount of carbon emission produced from house building materials on peat soil, using the Building Information Modeling method. The construction of houses on peat land is different from that of hard soil, because it requires to strengthen the foundation and to minimize the load on the superstructure of the building which was performed by choosing the type of material that is suitable for the location, and is also environmentally friendly. The carbon emission was calculated using a quantitative approach, where the volume of the material used was multiplied by its emission coefficient. The volume of material was obtained using the Building Information Modeling method, while the emission coefficients were acquired by utilizing the inventory data from ICE University of Bath and several literature studies. The results showed that the types of materials that produced the largest emissions were cement, mild steel, and wood, which had 14,051.90 KgCO_2eq/house, 9,565.89 KgCO_2eq/house, and 7,865.75 KgCO_2eq/house, carbon value respectively. After redesigning the building and replacing light steel with wood, the emission reduction was 5.01% from a total of 42,523.33 KgCO_2eq/house or 2,109 KgCO_2eq/house with a saving of Rp. 154,397.04 or 10.87/house. Based on data from Central Bureau of Statistics of the City of Palangka Raya, the number of houses built in Palangka Raya City reached 918 units with an average building area of 45 - 70 m², it is estimated to save Rp. 141,397,482.72 or $ 9,978.66. It shows the importance of environmentally friendly innovations in designs and the selection of low-emission materials, which has a positive impact on finance and climate sustainability. This finding is expected to provide insights for the government in the implementation of housing construction policies that prioritize environmental factors which reduce the level of carbon produced during the construction process and its operation.

ENERGY PERFORMANCE OF BUILDINGS USING ELECTROCHROMIC SMART WINDOWS WITH DIFFERENT WINDOW-WALL RATIOS

ABSTRACT The electrochromic (EC) smart window is a promising intelligent technology for improving the energy performance of a building. When applying a new glazing material, the window-wall ratio (WWR) is regarded as a significant factor related to daylight and building energy losses. However, there have not been any studies examining the relationship between the efficiency of the EC smart window and the WWR. The aim of this study is to provide strategies for mitigating energy losses and environmental impacts from window elements in an office building. It focuses on optimizing the WWR of EC smart windows to increase building energy efficiency. Double EC, low-emissivity (low-E), and clear glazing materials are simulated combined with five WWRs from 0% to 80% with an interval of 20%, four window orientations, and humid subtropical and Mediterranean climates. The results show that a 40% WWR in a southern-facing building façade using a humid subtropical climate setting provides the optimum energy performance of EC glazing among all the configurations tested. Since it was also found that EC glazing reduces the cooling load, it is more suitable for climate conditions characterized by a hotter temperature with greater solar irradiation. Future research should consider the impact of WWR when balancing thermal, lighting and ventilation requirements, and the properties of EC glazing.

Ecological Footprint of Residential Buildings in Composite Climate of India—A Case Study

Buildings are accountable for waste generation, utilization of natural resources, and ecological contamination. The construction sector is one of the biggest consumers of resources available naturally and is responsible for significant CO2 emissions on the planet. The effects of the buildings on the environment are commonly determined using Life Cycle Assessments (LCA). The investigation and comparison of the Life Cycle Ecological Footprint (LCEF) and Life Cycle Energy (LCE) of five residential buildings situated in the composite climatic zone of India is presented in this study. The utilization of resources (building materials) along with developing a mobile application and a generic model to choose low emission material is the uniqueness of this study. The utilization of eco-friendly building materials and how these are more efficient than conventional building materials are also discussed. In this investigation, the two approaches, (a) Life Cycle Energy Assessment (LCEA) and (b) Life Cycle Ecological Footprint (LCEF), are discussed to evaluate the impacts of building materials on the environment. The energy embedded due to the materials used in a building is calculated to demonstrate the prevalence of innovative construction techniques over traditional materials. The generic model developed to assess the LCEA of residential buildings in the composite climate of India and the other results show that the utilization of low-energy building materials brings about a significant decrease in the LCEF and the LCE of the buildings. The results are suitable for a similar typology of buildings elsewhere in different climatic zone as well. The MATLAB model presented will help researchers globally to follow-up or replicate the study in their country. The developed user-friendly mobile application will enhance the awareness related to energy, environment, ecology, and sustainable development in the general public. This study can help in understanding and thus reducing the ecological burden of building materials, eventually leading towards sustainable development.

Silver-modified chromium(III) oxide as multi-band compatible stealth materials for visual/ infrared stealth and radar wave transmission

Here we proposed a strategy of modifying colored pigments with low emissivity materials to develop multi-band compatible stealth materials. The silver-modified Cr2O3 particles were first prepared for achieving visual/infrared stealth and radar wave transmission simultaneously. The electrical conductivity increased significantly and the emissivity reduced effectively of Cr2O3@Ag hybrid powders with the increase of Ag content. By employing silicone resin as the binder, and Cr2O3@Ag (X mol·L−1) as the filler, coatings were prepared to investigate the stealth performance. The coating with 65 wt% Cr2O3@Ag (0.2 mol⋅L−1) content achieved the lowest emissivity of 0.760. Particularly, the complex permittivity increased slowly and the transmittance was over 90% at the coating thickness within 0.3 mm. The high transmittance of radar waves is attributed to the good impedance matching between Cr2O3 and free space, along with the space between the Ag particles. Additionally, the brownish-green Cr2O3@Ag pigment showed a lower visible-near infrared reflectance than pure Cr2O3. The proposed method provides an idea for the design of colored coating with low emissivity and high radar wave transmission for application in stealth technology.

2D Ti3 C2 Tx MXenes: Visible Black but Infrared White Materials.

Black inorganic materials with low infrared absorption/emission (or IR white) are rare in nature but highly desired in numerous areas, such as solar-thermal energy harvesting, multispectral camouflage, thermal insulation, and anti-counterfeiting. Due to the lack of spectral selectivity in intrinsic materials, such counter-intuitive properties are generally realized by constructing complicated subwavelength metamaterials with costly nanofabrication techniques. Here, the intrinsically low mid-IR emissivity (down to 10%) of the 2D Ti3 C2 Tx MXene is reported. Associated with a high solar absorptance (up to 90%), it embraces the best spectral selectivity among the reported intrinsic black solar-absorbing materials. Its appealing potential in several of the aforementioned areas is experimentally demonstrated. First-principles calculations reveal that the IR emissivity of MXene relies on both the nanoflake orientations and terminal groups, indicating great tunability. The calculations also suggest more potential low-emissivity MXenes including Ti2 CTx , Nb2 CTx , and V2 CTx . This work opens the avenue to further exploration of a family of intrinsically low-emissivity materials with over 70 members.

Numerical and experimental investigation of heat transfer across semi-transparent horizontal screen layers

Estimating the total heat flux passing through layers of materials is commonly used to determine the performance and potential of thermal isolation for general building design. The thermal properties of building glazing have been studied theoretically and experimentally for several decade. In this study, an enhanced algorithm for calculating the heat transfer through semi-transparent screens was developed and validated via published data and in-site experiments in order to analyze thermal properties of different screen materials and their combinations under more realistic conditions. The proposed algorithm allows to simplify the linearization of a nonlinear system, which is solved by inverting a tridiagonal matrix. Overall heat transfer coefficients (U-values) for single and multiple thin-screens were calculated numerically and measured using the hot-box method. The building insulating materials such as glass, polymers, aluminium films, and selected commercial thermal screens were examined. The cross-validated results indicated good agreement between calculated, measured and previously published results demonstrating the abilities of the method to predict new data for materials and their combinations that have not yet been estimated. Moreover, the algorithm allows to adopt the experimentally validated results to real ambient conditions by applying relevant scaling methods. The following results demonstrate the insulation properties of various commercial thermal screens. It is found that U-values reduce by 30% and 15% for the combination of a glass screen with an additional layer of a transparent infra-red (IR) radiation absorbing screen and a polyethylene screen, respectively. In comparison, the contributions of an additional screen containing aluminium foil strips could reduce the U-value by about 80% and 70% for polyethylene and glass cover screen, respectively. It was confirmed that low-emissivity materials have a more significant effect on reducing the U-value than insulating materials with IR-absorbing properties. The approach is valid for investigating the performance of thermal insulation in different enclosures, glazing in buildings, or moveable thermal screens in greenhouses.

Energy Saving Preparation and Evaluation of a Novel Polycarboxylate Superplasticizer

A novel polycarboxylate superplasticizer (PCE) with energy saving preparation was elaborately designed and synthesized by using acrylic acid (AA), hydroxypropyl acrylate (HPA) and isopentenyl polyethylene glycol (IPEG) as monomers. To investigate the effects of the preparation method on the effectiveness of PCE, the PCEs were prepared from energy-saving method and common method respectively, and the hydration heat evolutions of the cement pastes containing these PCEs were comparatively probed. Furthermore, the working mechanisms of the PCEs by different preparations were identified via adsorption behavior, adsorption kinetic and Zeta potential of the PCE on cement surfaces. The results showed that, this novel PCE prepared in an energy saving manner can significantly prolong the hydration process and present a stronger adsorption capacity. In addition, the adsorption of this PCE on cement surface exhibited a characteristic of pseudo first order kinetic equation model. The evaluation in energy conservation showed that, this energy saving preparation can save 1.548×104 kJ per 10 ton production. The aim of this study is to provide a new avenue to synthesize a PCE with economical method which achieves energy-saving preparation. Due to the indispensable application in construction industry, the innovations from this study contribute to the low energy-consumption production and high eco-effectiveness of the novel PCE, which has potential applications in low-emission building materials.

Quantifying Environmental Burdens of Plasters Based on Natural vs. Flue Gas Desulfurization (FGD) Gypsum

The ongoing global climate change and the associated environmental degradation pose a threat to Europe and the rest of the world. Raw materials and energy are required to produce building materials, which are used for construction purposes. Resulting buildings and structures generate waste during construction, operation, and demolition, and they emit potentially harmful substances. Thus, the key to achieving climate goals is to support low-emission materials and technologies in the construction sector, significantly impacting the environment. In the European Union, building materials are not yet subject to mandatory sustainability assessment during the assessment and verification of constancy of performance (AVCP). Objective evaluation of construction materials’ environmental impact requires it to be carried out based on production data on an industrial scale. This article presents the environmental impact of premixed gypsum-based plasters, commonly used in modern construction. Nine environmental indicators (global warming potential (GWP), depletion potential of the stratospheric ozone layer (ODP), acidification potential (AP), eutrophication potential (EP), formation potential of tropospheric ozone (POCP), abiotic depletion potential (ADP)-elements, ADP-fossil fuels, renewable primary energy resources (PERT), and nonrenewable primary energy resources (PERNT)) of premixed gypsum plasters based on natural and flue gas desulfurization (FGD) gypsum were estimated and discussed. Knowledge of the construction products’ environmental impact is fundamental for creating reliable databases. AVCP of construction materials in the future will use the data collected during the voluntary environmental impact evaluation.

FEM simulation of temperature field in a resistance-heated diamond anvil cell

The temperature of the sample in a resistance-heated diamond anvil cell is difficult to be measured directly and usually is calibrated by reading from the thermocouple attached to the diamond bevel. It is unclear how the temperature difference between the diamond bevel and the sample is affected by external factors such as thermal radiation and air convection. We performed a finite-element method simulation of the temperature field in the resistance-heated diamond anvil cell under different external conditions, and our simulations demonstrate that a thermal insulation cover of a low emissivity material and a unique double-layer structure can effectively reduce the temperature difference. Meanwhile, there is a non-negligible difference between the sample temperature at ambient pressure and that at high pressure when the diamond bevel has the same temperature. Some results of simulations have been confirmed by experiments using a designed double-layer cover.