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Journal articles on the topic 'Heat-isolation materials'

Author: Grafiati
Published: 30 May 2022

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1

Sun, Zi Qiang, Chang Zheng Chen, and Huang Liu. "Vibration Reduction of Water Source Heat Pump Units Based on Particle Damping Materials." Advanced Materials Research 532-533 (June 2012): 220–23. http://dx.doi.org/10.4028/www.scientific.net/amr.532-533.220.

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Spring vibration isolators and rubber damping vibration isolators are often used in active isolation engineering of water source heat pump units. The method is inefficient in shock and low frequency vibration isolation. Because the stiffness of equipments reduces with the isolation system the vibration severity itself becomes too big for working safely. Particle damping materials can absorb vibration energy to reduce vibration. The paper testifies that successful application of particle damping materials in vibration reduction of water source heat pump units is a practical simple way with low cost.
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2

Vaziri, Sam, Eilam Yalon, Miguel Muñoz Rojo, Saurabh V. Suryavanshi, Huairuo Zhang, Connor J. McClellan, Connor S. Bailey, et al. "Ultrahigh thermal isolation across heterogeneously layered two-dimensional materials." Science Advances 5, no. 8 (August 2019): eaax1325. http://dx.doi.org/10.1126/sciadv.aax1325.

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Heterogeneous integration of nanomaterials has enabled advanced electronics and photonics applications. However, similar progress has been challenging for thermal applications, in part due to shorter wavelengths of heat carriers (phonons) compared to electrons and photons. Here, we demonstrate unusually high thermal isolation across ultrathin heterostructures, achieved by layering atomically thin two-dimensional (2D) materials. We realize artificial stacks of monolayer graphene, MoS2, and WSe2 with thermal resistance greater than 100 times thicker SiO2 and effective thermal conductivity lower than air at room temperature. Using Raman thermometry, we simultaneously identify the thermal resistance between any 2D monolayers in the stack. Ultrahigh thermal isolation is achieved through the mismatch in mass density and phonon density of states between the 2D layers. These thermal metamaterials are an example in the emerging field of phononics and could find applications where ultrathin thermal insulation is desired, in thermal energy harvesting, or for routing heat in ultracompact geometries.
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3

Patil, Ganesh U., Oluseyi Babatola, Daniel Hsieh, Sanjiv Sinha, and Kathryn Matlack. "Three-dimensional periodic multifunctional lattice materials for simultaneous vibration isolation and heat conduction." Journal of the Acoustical Society of America 148, no. 4 (October 2020): 2578–79. http://dx.doi.org/10.1121/1.5147155.

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4

Wang, Lingyun, Weidong Zhu, Qing Wang, Qiang Xu, and Yinglin Ke. "A heat-balance method for autoclave process of composite manufacturing." Journal of Composite Materials 53, no. 5 (July 17, 2018): 641–52. http://dx.doi.org/10.1177/0021998318788918.

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In composite manufacturing, large composite parts usually exhibit high heating gradients during the autoclave process, which may intensify the process-induced residual stresses and deformations. As the thermal behavior of molds is of crucial importance to the curing performance of composites, a heat-balance method is presented to reduce the heating rate on overheated areas of molds, thus providing a more homogeneous curing process. The method is based on a local-isolation structure installed under the mold plate, which is used to change the local heat transfer coefficient of the mold. In the local-isolation structure application, an optimization process combining numerical simulations with a greedy genetic algorithm is developed to find the optimal layout and geometry of local-isolation structure in molds. The optimization results suggest that more uniform heating condition and more synchronous curing process can be achieved with the optimal design of local-isolation structure. In the case of a typical mold for C spar component, the maximum temperature difference in the composite part is reduce by 45.69%, while the maximum difference in degree of cure is decreased at a rate of 40.16%.
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5

Van Keer, R., and A. Handlovicová. "On a mathematical model for the heat transmission through transparent isolation materials in buildings." Mathematical Modelling of Systems 1, no. 2 (January 1995): 127–37. http://dx.doi.org/10.1080/13873959508837013.

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6

Pastushkov, P. P., S. I. Gutnikov, N. V. Pavlenko, D. Yu Zheldakov, and M. D. Stolyarov. "Heat conductivity of aerogel-based rolled materials for high-thermal isolation for equipment and pipelines." IOP Conference Series: Materials Science and Engineering 896 (August 13, 2020): 012103. http://dx.doi.org/10.1088/1757-899x/896/1/012103.

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7

Li, Zhen, Lei Wu, Hu Zhang, Yueming Li, and Heow Pueh Lee. "Dual-functional metamaterial with vibration isolation and heat flux guiding." Journal of Sound and Vibration 469 (March 2020): 115122. http://dx.doi.org/10.1016/j.jsv.2019.115122.

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8

Houghton, J. M., D. B. Ingham, and P. J. Heggs. "The One-Dimensional Analysis of Oscillatory Heat Transfer in a Fin Assembly." Journal of Heat Transfer 114, no. 3 (August 1, 1992): 548–52. http://dx.doi.org/10.1115/1.2911316.

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Studies of the transient heat transfer within extended surfaces have so far considered the fins in isolation. The isolated fin model is not representative of the physical boundary conditions within an extended surface heat exchanger since it does not account for the thermal effects of the supporting interface. The aim of this study is to extend the work on transient heat transfer within finned surfaces by incorporating the supporting wall in the problem. A mathematical one-dimensional solution for harmonic oscillatory heat transfer in a fin assembly is derived. It is concluded that, unlike steady-state situations, the transient heat transfer in a fin assembly can only be found by considering both the wall and the fins simultaneously.
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9

Sun, Chuang, Yang Zhao, De Fu Li, Qing Ai, and Xin Lin Xia. "Thermal Response Characteristics of Flat Plate Heated by High Temperature and High Speed Flow." Applied Mechanics and Materials 448-453 (October 2013): 3316–19. http://dx.doi.org/10.4028/www.scientific.net/amm.448-453.3316.

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According to the view of heat transfer, the process of the fluid flow with high temperature and high speed over a flat plate may be considered as the heat transfer process within a compressible thermal boundary layer. Based on the numerical results of thermal isolation assumption, combining the temperature comparison with modification method, a coupled method of convection heat transfer coefficient with temperature field of the plate is established, and the characteristics of the thermal response for the flat plate is dominated. Take some ribbed plates as instances, the convection heat transfer coefficient and temperature field of the plate are simulated through the provided coupled method. The results show that, not only the position and materials of the plate influence the convection heat transfer coefficient, but also the time.
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10

Marušáková, Daniela, Petra Bublíková, Jan Berka, Jiří Hamáček, and Jana Kalivodová. "Microstructure Evaluation of Ceramic Materials Used in the Generation IV Reactors." Materials Science Forum 891 (March 2017): 462–67. http://dx.doi.org/10.4028/www.scientific.net/msf.891.462.

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Ceramics are candidate materials for high temperature reactors as perspective materials for fuel claddings, isolation, holders, exchangers and other heat-stressed components. In this context, particularly Al2O3 which can resist high temperatures is often mentioned as cladding material. Ceramics can also be used for high-temperature systems, mainly for components that are not directly exposed to neutron flux in the reactor core. Under this study, high alumina products - mullite Lunit 73, alumina products Luxal 203 and AG 202 were exposed to the high-temperature air atmosphere and helium atmosphere up to 900°C. Exposed specimens were mechanically polished to study the microstructural changes after exposition. Microstructural evaluation was performed by Light Optical and Scanning Electron Microscopy. Luxal 203 and AG 202 showed no changes in the microstructure, whereas in Lunit 73 new phases were observed.
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11

Kim, Min-Kyeong, Yang-Kyu Choi, and Jun-Young Park. "Power Reduction in Punch-Through Current-Based Electro-Thermal Annealing in Gate-All-Around FETs." Micromachines 13, no. 1 (January 13, 2022): 124. http://dx.doi.org/10.3390/mi13010124.

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Device guidelines for reducing power with punch-through current annealing in gate-all-around (GAA) FETs were investigated based on three-dimensional (3D) simulations. We studied and compared how different geometric dimensions and materials of GAA FETs impact heat management when down-scaling. In order to maximize power efficiency during electro-thermal annealing (ETA), applying gate module engineering was more suitable than engineering the isolation or source drain modules.
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12

Zhu, Xiao Yan, Yong Li, Jia Ping Wang, Ya Wei Zhai, Jun Bo, and Jian Fang Zhang. "Preparation of Both Reactive α-Si3N4 and SiC Mixed Powder in Flame-Isolation Nitridation Shuttle Kiln." Key Engineering Materials 512-515 (June 2012): 17–23. http://dx.doi.org/10.4028/www.scientific.net/kem.512-515.17.

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α-Si3N4 possesses excellent sintering activity, which is used to prepare high performance Si3N4-based ceramics and composite refractory. Si3N4 powder is always synthesized by nitriding silicon in controlled-atmosphere furnace whose furnace volume is very small(effective volume: 1840×1420×1660mm), the extreme reaction heat is difficult to diffuse, which leads to high reaction temperature and conversion of α-Si3N4 to β-Si3N4, thus α-Si3N4 is difficult to be obtained in controlled-atmosphere furnace. While flame-isolation nitridation shuttle kiln has much larger furnace volume to conduct reaction heat (effective volume: 11500×4190×1684mm), so it owns homogeneous temperature field and stable low-temperature environment which benefits the preparation of α-Si3N4. Thermodynamic analysis of Si-N system is shown that Si3N4 can be formed by two formats: direct nitridation of Si(s) and indirect nitridation of SiO(g); to ensure completely nitridation, the particle size of silicon powder should be less than 88μm. With reclaimed powder from polysilicon cutting slurry as starting materials, both reactive α-Si3N4 and SiC mixed powder were successfully prepared in flame-isolation nitridation shuttle kiln. Because of the gas-gas reaction between SiO(g) and N2(g), α-Si3N4 is fiber-like and in favor of processing high quality Si3N4-based materials.
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13

Graf, Marius, Matthias Kuntz, Hermann Autenrieth, and Ralf Müller. "Investigation of Size Effects Due to Different Cooling Rates of As-Quenched Martensite Microstructures in a Low-Alloy Steel." Applied Sciences 10, no. 15 (August 4, 2020): 5395. http://dx.doi.org/10.3390/app10155395.

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Martensite transformation is a complex mechanism in materials that is classically initiated by a suitable heat treatment. This heat treatment process can be optimized based on a better understanding of the physical mechanisms on the length scale of several prior austenite grains. It is therefore appropriate to consider individual process steps of heat treatment in isolation. The aim of this study is to characterize the microstructural size changes caused by a variation of the cooling rate applied during the quenching process. For this purpose, individual martensitic microstructures from different heat treatments are analyzed using the electron backscatter diffraction (EBSD) method. With special orientation relationships between the parent austenite and martensite, the structure of the prior austenite grains and the close packet plane packets can then be reconstructed. The influence of the heat treatments on these characteristics as well as on the martensite blocks is thus quantified. No significant influence of the quenching rate on the sizes of martensite blocks and packets could be found.
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14

Sukarno, Ragil, Nandy Putra, Imansyah Ibnu Hakim, Fadhil Fuad Rachman, and Teuku Meurah Indra Mahlia. "Utilizing heat pipe heat exchanger to reduce the energy consumption of airborne infection isolation hospital room HVAC system." Journal of Building Engineering 35 (March 2021): 102116. http://dx.doi.org/10.1016/j.jobe.2020.102116.

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15

Jahan, Aklima, Md Ashraful Alam, Sekai Yonezawa, Eiichi Suzuki, and Hitoshi Yashiro. "(Digital Presentation) Corrosion Behavior of Aluminum-Carbon Composite Bipolar Plates in Polymer Electrolyte Membrane Fuel Cells." ECS Transactions 108, no. 7 (May 20, 2022): 131–41. http://dx.doi.org/10.1149/10807.0131ecst.

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Bipolar plate, aluminum is one of the most promising alternatives that can capable of uniform distribution of reactive gases over active areas and removal of the heat and exhaust water from the PEMFC. In this work, PEM fuel cell was operated using the bipolar plate constructed of two materials: a channel former made of glassy carbon and a gas isolation plate made of aluminum. Aluminum gas isolation plate at cathode side remained glossy after even1000 h cell operation. In contrast, an oxide layer with a thickness of about 1 μm was formed on the gas isolation plate at anode side. In the simulated corrosion test, a thick oxide layer was formed when aluminum was immersed in water while only a thin oxide layer was formed in the saturated water vapor. The microscopic images, scanning electron microscopy (SEM) images, energy dispersive X-ray (EDX) spectra and transmission electron microscopy (TEM) images were taken to evaluate the surface morphology, elemental composition and other analyses.
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16

Edward, Lisowski, and Lisowski Filip. "Influence of vacuum level on insulation thermal performance for LNG cryogenic road tankers." MATEC Web of Conferences 240 (2018): 01019. http://dx.doi.org/10.1051/matecconf/201824001019.

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In this paper, thermal properties of materials for evacuated insulation systems of double-walled cryogenic tanks were discussed. Than the comparison of insulation variants for LNG cryogenic road tankers was presented. The use of several layers of insulation made of materials such as aerogel and fiberglass or the use of multilayer isolation (MLI) has been compared to the use of perlite powder. The average heat flux through the tank walls and insulation system has been compared under different vacuum levels and in the absence of vacuum. The comparative analysis was performed by applying transient thermal analysis using finite element method.
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17

Sukamto, Dwinanto, François Gloriant, and Monica Siroux. "Thermal performance evaluation of a bioclimatic ventilated wall using a Hot Box." E3S Web of Conferences 294 (2021): 04003. http://dx.doi.org/10.1051/e3sconf/202129404003.

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Nowadays, external isolation is highly recommended for both building renovation and new building construction. This isolation requires the installation of structure protecting the insulating materials from the humidity and weather variations. One of the current techniques is the installation of ventilated facades. The recovered energy by this process could be used in winter for the preheating of ventilated air or could be evacuated in summer to protect the building from potential overheating. This study describes the design and application of Hot Box developed specifically to test the thermal performance of a ventilated bioclimatic wall. Based on experiments test, this paper discusses the experimental set-up and the thermal metrology. Data collected from testing a ventilated wall were used to estimate the convection heat transfer coefficients of the ventilated wall.
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18

Orzechowski, Tadeusz, and Mateusz Orzechowski. "Optimal thickness of various insulation materials for different temperature conditions and heat sources in terms of economic aspect." Journal of Building Physics 41, no. 4 (June 1, 2017): 377–93. http://dx.doi.org/10.1177/1744259117708733.

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The article presents the methodology for calculating the optimal insulation thickness that is related to the quality of energy supply and fuel prices. Assuming that the total cost following renovation is the sum of the costs of heating and thermal upgrading, it was shown that when calculating the optimal insulation thickness, the thermal resistance of the outer walls should be taken into account. Such calculations, in addition to the characteristics of the heat source, should be carried out taking into account local weather conditions. The study presents the results of such calculations for the building heated with gas and the air-source heat pump. The results of the investigations are referred to the mean climatic conditions recorded in the last 10 years. It was found that for thermal upgrading with the use of foamed polystyrene having the optimum thickness, total investment costs are almost the same, regardless of polystyrene thermal properties. The same also refers to energy costs. The article also provides sample calculations for plaster, the main ingredient of which is perlite. In the case of internal thermal upgrading of the historic buildings, such isolation is recommended in order to prevent moisture problems inside the envelope.
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19

Kamperidou, Vasiliki, and Paschalina Terzopoulou. "Anaerobic Digestion of Lignocellulosic Waste Materials." Sustainability 13, no. 22 (November 19, 2021): 12810. http://dx.doi.org/10.3390/su132212810.

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Nowadays, the climate mitigation policies of EU promote the energy production based on renewable resources. Anaerobic digestion (AD) constitutes a biochemical process that can convert lignocellulosic materials into biogas, used for chemical products isolation or energy production, in the form of electricity, heat or fuels. Such practices are accompanied by several economic, environmental and climatic benefits. The method of AD is an effective method of utilization of several different low-value and negative-cost highly available materials of residual character, such as the lignocellulosic wastes coming from forest, agricultural or marine biomass utilization processes, in order to convert them into directly usable energy. Lignin depolymerization remains a great challenge for the establishment of a full scale process for AD of lignin waste. This review analyzes the method of anaerobic digestion (biomethanation), summarizes the technology and standards involved, the progress achieved so far on the depolymerization/pre-treatment methods of lignocellulosic bio-wastes and the respective residual byproducts coming from industrial processes, aiming to their conversion into energy and the current attempts concerning the utilization of the produced biogas. Substrates’ mechanical, physical, thermal, chemical, and biological pretreatments or a combination of those before biogas production enhance the hydrolysis stage efficiency and, therefore, biogas generation. AD systems are immensely expanding globally, especially in Europe, meeting the high demands of humans for clean energy.
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20

Lisowski, Edward, and Filip Lisowski. "Study on thermal insulation of liquefied natural gas cryogenic road tanker." Thermal Science 23, Suppl. 4 (2019): 1381–91. http://dx.doi.org/10.2298/tsci19s4381l.

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The tanks designed for liquefied natural gas transport must be thermally insulated from the environment due to the low condensing temperature of the gas. The effectiveness of thermal insulation significantly affects the tank's operating parameters and its operating costs. As there is no perfect insulation, there is a need for analyses that would determine its suitability in specific applications. In this paper the issue of heat transfer through double-walled cryogenic tanks with evacuated insulation system was discussed. Afterwards the study of insulation variants of liquefied natural gas cryogenic road tanker was presented. The use of several layers of insulation made of modern and efficient materials such as aero-gel and fiberglass or the use of multi-layer isolation has been considered and compared to the use of perlite powder. The heat flux through insulation systems was tested for different variants of evacuated insulation under residual gas pressure of 10-1 Pa, 10-3 Pa, and 100 kPa. Finally, for selected insulation variants, the heat leakage was tested for 50 m3 liquefied natural gas road tanker. The investigation of heat-flow for the transient thermal analysis was performed by applying finite element method. The aim of the study was to determine the variant of insulation system with the relatively low heat leakage to the tank and low cost of materials and vacuum production.
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21

Anas, K., Samson David, R. R. Babu, M. Selvakumar, and S. Chattopadhyay. "Energy dissipation characteristics of crosslinks in natural rubber: an assessment using low and high-frequency analyzer." Journal of Polymer Engineering 38, no. 8 (August 28, 2018): 723–29. http://dx.doi.org/10.1515/polyeng-2016-0425.

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AbstractThe dynamic deformation of a viscoelastic material can cause heat generation. This heat generation is an aspect of energy dissipation. The present paper investigates the contribution of crosslink type and density on energy dissipation mechanism in natural rubber compounds. The influences of these elements are investigated using a very high frequency (VHF) analyzer (VHF 104) and a dynamical mechanical analyzer (DMA). The VHF 104 analyzer follows transmissibility and vibration isolation principle, whereas DMA works on dynamical mechanical the deformation principle. Higher crosslink density promotes lower heat generation in rubber compounds. Tanδinterpretation for energy dissipation characteristics of rubbery compounds should be done judiciously to avoid wrong interpretations. Polysulfidic linkages show higher damping ratios (ζ) than monosulfidic or disulfidic linkages due to their dissipative nature. The natural frequency (ωn) of a system at a given mass is the function of its crosslink density.
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22

Kizys, Marina M. L., Mirian G. Cardoso, Susan C. Lindsey, Michelle Y. Harada, Fernando A. Soares, Maria Clara C. Melo, Marlyn Z. Montoya, et al. "Optimizing nucleic acid extraction from thyroid fine-needle aspiration cells in stained slides, formalin-fixed/paraffin-embedded tissues, and long-term stored blood samples." Arquivos Brasileiros de Endocrinologia & Metabologia 56, no. 9 (December 2012): 618–26. http://dx.doi.org/10.1590/s0004-27302012000900004.

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OBJECTIVE: Adequate isolation of nucleic acids from peripheral blood, fine-needle aspiration cells in stained slides, and fresh and formalin-fixed/paraffin-embedded tissues is crucial to ensure the success of molecular endocrinology techniques, especially when samples are stored for long periods, or when no other samples can be collected from patients who are lost to follow-up. Here, we evaluate several procedures to improve current methodologies for DNA (salting-out) and RNA isolation. MATERIALS AND METHODS: We used proteinase K treatment, heat shock, and other adaptations to increase the amount and quality of the material retrieved from the samples. RESULTS: We successfully isolated DNA and RNA from the samples described above, and this material was suitable for PCR, methylation profiling, real-time PCR and DNA sequencing. CONCLUSION: The techniques herein applied to isolate nucleic acids allowed further reliable molecular analyses. Arq Bras Endocrinol Metab. 2012;56(9):618-26
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23

Mironov, Viktor, Mihails Lisicins, and Irina Boiko. "Sandwich Panels Made of Perforated Metal Materials." Solid State Phenomena 320 (June 30, 2021): 155–60. http://dx.doi.org/10.4028/www.scientific.net/ssp.320.155.

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Nowadays, the growing attention has focused on the sandwich-structured composites (panels), especially on those, which are environmentally friendly. The sandwich panel is a special type of the composites made of at least three layers: a core and a skin-layer bonded to each side. The aim of this paper is to investigate the possibility of using of perforated metallic materials for producing sandwich panels for the different application in the civil engineering. By using the perforated metallic materials in combination with different core materials or by using the perforated metallic material as the core material the wide range of products for the construction, damping or isolation purposes could be manufactured. In the paper the example of using of perforated metallic sheet materials for manufacturing the sandwich panels is proposed. Both, the simulation and experimental studies (mechanical testing) were carried out in order to assess the load-bearing capacity of sandwich panels and to prove the applicability of the proposed sandwich panels for construction structures. For the analysis of the achieved structures the finite element analysis (FEA) software was used. The simulation results are well-coincided with the results of the experimental studies. Thus, new types of the sandwich panels and the manufacturing technology thereof are shown its reliability and could be recommended for application in the different branches, in particular for producing lightweight ceiling panels with filler from heat insulating materials.
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24

Kimmins, S. T., N. S. Walker, and D. J. Smith. "Creep deformation and rupture of low alloy ferritic weldments under shear loading." Journal of Strain Analysis for Engineering Design 31, no. 2 (March 1, 1996): 125–33. http://dx.doi.org/10.1243/03093247v312125.

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A novel testing technique has been employed to study the creep properties of ferritic steel weldments under shear loading. The technique allows examination of microstructurally distinct regions, such as the type IV region of the heat-affected zone, in relative isolation from adjacent material. When results from the shear tests are compared with uniaxial data an appropriate stress for determining creep rupture under multi-axial loading may be deduced. The stress rupture behaviour of shear and uniaxial tests as a function of stress and temperature are consistent. It is suggested that this test technique deserves wider application for the examination of the creep properties of materials that are microstructurally inhomogeneous.
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25

Hashimoto, Kinro, Akio Maeda, Kiyoshi Hosoya, and Yoshihiro Todani. "Specialty Elastomers for Automotive Applications." Rubber Chemistry and Technology 71, no. 3 (July 1, 1998): 449–519. http://dx.doi.org/10.5254/1.3538491.

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Abstract Various elastomers are used for automotive components because of their physical properties, chemical properties, durability, etc. There are belts to transmit energy, seals to support radial or reciprocating parts, gaskets and O-rings to seal in oils and fuels, hoses to deliver liquid and gases and diaphragms to control them. Figure 1 shows one example of elastomers for gasoline engines reported by Akema and Yoshida. Rubbers are soft polymeric materials having generally 100 MPa of Young's modulus (shown in Figure 2) for the normally applied temperature range. They are widely used for the buffer position between high modulus materials such as metals, plastics, glasses, etc., in energy transmission, liquid delivery, and energy isolation positions. The materials are selected for their resistance to fuels, oils, and heat; as well as their cold flexibility and sealing ability. However, different materials are sometimes selected for the same device depending upon such factors as applied temperature, class of fuels and oils, and the engineering design of the car. The many problems confronting the automotive industry these days are shown in Table A-I. They are roughly classified into two areas: environmental and safety. Elastomers for automotive applications have been changing to solve many kinds of problems. Table A-II shows the trends of rubber materials being used for automotive parts. High performance rubbers, which have heat resistance, long life, low permeability, good abrasion resistance, and so on, are all being adopted.
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26

Ovchinnikov, Vasiliy P., Pavel V. Ovchinnikov, Alexander V. Melekhov, and Oksana V. Rozhkova. "Challenges and their remedies while cementing production casing in high-temperature wells." Oil and Gas Studies, no. 1 (April 4, 2019): 39–46. http://dx.doi.org/10.31660/0445-0108-2019-1-39-46.

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The development of the global oil industry is closely related to the exploration of new oil and gas fields through the drilling new deep and ultra-deep wells, as well as the application of modern methods of hydrocarbon production. Usage of new methods of production, increasing the depth of the wells, bottomhole temperatures and pressures sets strict requirements and restrictions for the applied plugging materials. Oil well cements must have a long time of thickening to successfully complete the cementing process, grouting stone must have high strength characteristics, heat-resistant properties at high temperatures and provide reliable isolation of the annulus, also have corrosion resistance, ensure durability of the well lining.
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27

Umnyakova, Nina, Igor Bessonov, Alex Zhukov, and Ekaterina Zinoveva. "Arctic Climate Insulation Systems." MATEC Web of Conferences 298 (2019): 00012. http://dx.doi.org/10.1051/matecconf/201929800012.

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The article describes the features of the implementation of insulation systems in extreme climatic conditions, including in conditions of significant negative and alternating temperatures, high wind speeds and more. It is noted that the adaptation of building systems to similar operating conditions places special demands on heat-insulating materials, as well as resistance to mechanical and climatic influences, vapor permeability, and stability of properties for the entire period of operation. Taking into account the temperature regime of the polar territories, it becomes necessary to develop special solutions for the creation of insulating shells that have high heat engineering uniformity and durability, as well as those that are resistant to very negative and alternating temperatures. Also important is the heat, moisture, and vapor barrier properties of these systems. Taking into account the operational features of the polar territories, three main groups of objects requiring complex isolation and protection can be distinguished: residential buildings, roads on permafrost, modular buildings and residential capsules of mobile equipment. The article considers the feasibility of implementing such heat-efficient systems using foamed plastics, namely products based on extruded polystyrene foam and foamed polyethylene. Solutions are proposed for the implementation of overlaps over ventilated cellars, insulation of walls, roads and mobile structures.
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28

Yang, Xiaoping, Gaoxiang Wang, Cancan Zhang, Jie Liu, and Jinjia Wei. "Experimental Study on the Heat Transfer Performance of Pump-Assisted Capillary Phase-Change Loop." Applied Sciences 11, no. 22 (November 19, 2021): 10954. http://dx.doi.org/10.3390/app112210954.

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To overcome the two-phase flow instability of traditional boiling heat dissipation technologies, a porous wick was used for liquid-vapor isolation, achieving efficient and stable boiling heat dissipation. A pump-assisted capillary phase-change loop with methanol as the working medium was established to study the effect of liquid-vapor pressure difference and heating power on its start-up and steady-state characteristics. The results indicated that the evaporator undergoes four heat transfer modes, including flooded, partially flooded, thin-film evaporation, and overheating. The thin-film evaporation mode was the most efficient with the shortest start-up period. In addition, heat transfer modes were determined by the liquid-vapor pressure difference and power. The heat transfer coefficient significantly improved and the thermal resistance was reduced by increasing liquid-vapor pressure as long as it did not exceed 8 kPa. However, when the liquid-vapor pressure exceeded 8 kPa, its influence on the heat transfer coefficient weakened. In addition, a two-dimensional heat transfer mode distribution diagram concerning both liquid-vapor pressure difference and power was drawn after a large number of experiments. During an engineering application, the liquid-vapor pressure difference can be controlled to maintain efficient thin-film evaporation in order to achieve the optimum heat dissipation effect.
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Jakab, András, Viktor Hlavicka, Ágoston Restás, and Eva Lubloy. "Fire resistance of the vertical glass structures with thermal protection foil." Journal of Structural Fire Engineering 11, no. 3 (May 28, 2020): 395–407. http://dx.doi.org/10.1108/jsfe-01-2020-0004.

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Purpose During the building designing, it is very important to deal with the fire resistance of the structures. The designed materials for escape routes should be selected to ensure the usability of the structures until the time of escape. Planning affects the glass structures similarly, so these can also be partition walls and load bearing structures, although the latter is less applied on escape routes. The heat protection of the glasses can be improved with heat-protective foils, while fire protection is provided by gel intumescent material. Design/methodology/approach To research the topic of fire resistance, laboratory experiments were carried out on small-scaled glass elements with thermal protection foil at Budapest University of Technology and Economics at the Department of Construction Materials and Technologies. Findings Fire protection of small model specimens was tested with blowtorch fire and furnace heat load. During the experiments, six foils were tested. Single pane glass, double layered and triple glazed specimens were tested with blowtorch fire. Originality/value Fire protection of small model specimens was tested with blowtorch fire and furnace heat load. During the experiments, six foils were tested. Single pane glass, double layered and triple glazed specimens were tested with blowtorch fire. In case of heat-protected glazing, the foils on the “protected” side of the single pane glass do not have a fire protection effect based on blowtorch fire test. For double glassed specimens, the P35 foil has a perceptible effect, even for the requirements of the flame breakthrough (E, integrity), when the foil is placed on the inner side (position 3) of the second glass layer. The stratification of each triple glazed specimens was effective against blowtorch fire load (3 M, S4&P35), so (EI, integrity and isolation) it can meet the requirements of flame breakthrough and thermal insulation.
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Bessonov, Igor V., L. K. Bogomolova, Alexey D. Zhukov, and E. A. Zinoveva. "Building Systems Based on Foamed Modified Polymers." Key Engineering Materials 887 (May 2021): 446–52. http://dx.doi.org/10.4028/www.scientific.net/kem.887.446.

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Systems of floor insulation on the ground, isolation of roads and shallow foundations suggest the use of heat-insulating products resistant to moisture, the minerals contained in it, having low heat conductivity and water absorption and relatively high strength for compressive loads.The aim of the research was to study the possibility of using mineral substances containing crystalline water as a dispersed component. Firstly, such compounds as a reinforcing component increase the strength characteristics of products. Secondly, being flame retardants, they contribute to increasing the fire safety of materials and building systems in which these materials are used. To achieve this goal, two particular tasks were set: determination of the optimal consumption of mineral modifying additives; assessment of exploitative stability of the received products. It was found that the introduction of a mineral modifying additive can significantly increase the compressive strength by 10% deformation of samples from extruded polystyrene foam. The exploitative stability of products with a mineral additive varies slightly and depends on its consumption and uniform distribution in the product matrix. The effect of additive consumption on the change in the thermal conductivity of products has not been established. A nomogram has been built which allows one to evaluate the properties of products and determine the optimal consumption of a modifying additive.Systems of using products from modified extruded polystyrene foam in monolithic foundations with insulation for buildings erected on problem soils are considered.
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Maximov, Yu V., V. G. Merzlikin, O. V. Sidorov, A. A. Bekaev, and V. G. Sutugin. "Optical and thermal radiating characteristics of heat- insulated walls and elements of the high-speed diesel combustion chamber." Izvestiya MGTU MAMI 4, no. 2 (January 20, 2010): 130–35. http://dx.doi.org/10.17816/2074-0530-69682.

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The main objective of this research is the analysis of influence of optical and thermo radiating characteristics on the transient (steady state) temperature distributions inside the heat-insulating semitransparent (SHIC) и opaque (HIC) coatings for thermal regulation and control of walls and elements of the combustion chamber (СС) high speed diesel engines. Developed author's methodology of physical and mathematical simulation of parameters of the radiant and heat conductivity transfer was used to calculate optimal balance of optical and thermo radiating characteristics of coatings - as selectively absorbing and scattering materials with different transmittance, reflection and emittance depending on wavelength diapasons of irradiating or radiating heat fluxes. The paper presents a mathematical simulation of optimal balance of improved optical (transmittance, reflectance, absorption coefficients or absorption, scattering indexes) and thermo radiating (emittance coefficient) characteristics. It is considered the effect of the subsurface volumetric heating which at their display promotes decreasing of a surface overheating of coatings of the combustion chamber. It have been received by the numerical method temperature distributions for semitransparent heat-insulating coatings protecting metal substrate (CC wall) with different reflection of penetrating radiation by SHIC layer. It has been shown decreasing the surface temperature of SHIC in comparison with temperature of opaque HIC. The methods of improvement of thermal isolation of the combustion chamber with use heat-insulating coatings c are offered: 1) high volume reflection rλ > 60-80 % for thermal protection (barrier) against intensive radiation of red-hot soot particles of soot (λ ~ 0.7-2 μm) and 2) high surface emittance ελ > 80-90 % (λ >4- 5 μm) for counteraction convectional heat flux inside CС a diesel engine.
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Roh, J. W., J. S. Yang, S. H. Ok, Deok Ha Woo, Young Tae Byun, Young Min Jhon, Tetsuya Mizumoto, Woo Young Lee, and Seok Lee. "Low Temperature O2 Plasma-Assisted Wafer Bonding of InP and a Garnet Crystal for an Optical Waveguide Isolator." Solid State Phenomena 124-126 (June 2007): 475–78. http://dx.doi.org/10.4028/www.scientific.net/ssp.124-126.475.

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A novel process of wafer bonding between InP and a garnet crystal (Gd3Ga5O12, CeY2Fe5O12) based on O2 plasma surface-activation and low temperature heat treatment is presented. The O2 plasma assisted wafer bonding process was found to be very effective in bonding of InP and Gd3Ga5O12, providing good bonding strength and hydrophilicity as well as no voids in the interface, which is crucial for fabrication of an integrated optical waveguide isolator. The isolation ratio of an integrated optical waveguide isolator fabricated by the O2 plasma assisted wafer bonding process was obtained to be 2.9 dB.
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33

Barrow, Kaitlyn A., Lucille M. Rich, Elizabeth R. Vanderwall, Stephen R. Reeves, Jennifer A. Rathe, Maria P. White, and Jason S. Debley. "Inactivation of Material from SARS-CoV-2-Infected Primary Airway Epithelial Cell Cultures." Methods and Protocols 4, no. 1 (January 7, 2021): 7. http://dx.doi.org/10.3390/mps4010007.

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Given that the airway epithelium is the initial site of infection, study of primary human airway epithelial cells (AEC) infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will be crucial to improved understanding of viral entry factors and innate immune responses to the virus. Centers for Disease Control and Prevention (CDC) guidance recommends work with live SARS-CoV-2 in cell culture be conducted in a Biosafety Level 3 (BSL-3) laboratory. To facilitate downstream assays of materials from experiments there is a need for validated protocols for SARS-CoV-2 inactivation to facilitate safe transfer of material out of a BSL-3 laboratory. We propagated stocks of SARS-CoV-2, then evaluated the effectiveness of heat (65 °C) or ultraviolet (UV) light inactivation. We infected differentiated human primary AECs with SARS-CoV-2, then tested protocols designed to inactivate SARS-CoV-2 in supernatant, protein isolate, RNA, and cells fixed for immunohistochemistry by exposing Vero E6 cells to materials isolated/treated using these protocols. Heating to 65 °C for 10 min or exposing to UV light fully inactivated SARS-CoV-2. Furthermore, we found in SARS-CoV-2-infected primary AEC cultures that treatment of supernatant with UV light, isolation of RNA with Trizol®, isolation of protein using a protocol including sodium dodecyl sulfate (SDS) 0.1% and Triton X100 1%, and fixation of AECs using 10% formalin and Triton X100 1%, each fully inactivated SARS-CoV-2.
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Barrow, Kaitlyn A., Lucille M. Rich, Elizabeth R. Vanderwall, Stephen R. Reeves, Jennifer A. Rathe, Maria P. White, and Jason S. Debley. "Inactivation of Material from SARS-CoV-2-Infected Primary Airway Epithelial Cell Cultures." Methods and Protocols 4, no. 1 (January 7, 2021): 7. http://dx.doi.org/10.3390/mps4010007.

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Given that the airway epithelium is the initial site of infection, study of primary human airway epithelial cells (AEC) infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) will be crucial to improved understanding of viral entry factors and innate immune responses to the virus. Centers for Disease Control and Prevention (CDC) guidance recommends work with live SARS-CoV-2 in cell culture be conducted in a Biosafety Level 3 (BSL-3) laboratory. To facilitate downstream assays of materials from experiments there is a need for validated protocols for SARS-CoV-2 inactivation to facilitate safe transfer of material out of a BSL-3 laboratory. We propagated stocks of SARS-CoV-2, then evaluated the effectiveness of heat (65 °C) or ultraviolet (UV) light inactivation. We infected differentiated human primary AECs with SARS-CoV-2, then tested protocols designed to inactivate SARS-CoV-2 in supernatant, protein isolate, RNA, and cells fixed for immunohistochemistry by exposing Vero E6 cells to materials isolated/treated using these protocols. Heating to 65 °C for 10 min or exposing to UV light fully inactivated SARS-CoV-2. Furthermore, we found in SARS-CoV-2-infected primary AEC cultures that treatment of supernatant with UV light, isolation of RNA with Trizol®, isolation of protein using a protocol including sodium dodecyl sulfate (SDS) 0.1% and Triton X100 1%, and fixation of AECs using 10% formalin and Triton X100 1%, each fully inactivated SARS-CoV-2.
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35

Andrés-Valeri, Valerio C., Luis A. Sañudo-Fontaneda, Carlos Rey-Mahía, Stephen J. Coupe, and Felipe P. Alvarez-Rabanal. "Thermal Performance of Wet Swales Designed as Multifunctional Green Infrastructure Systems for Water Management and Energy Saving." Proceedings 2, no. 23 (November 5, 2018): 1433. http://dx.doi.org/10.3390/proceedings2231433.

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Lack of city space and conventional drainage systems failures have derived in the need to implement Green Stormwater Infrastructure (GSI) techniques which provide multifunctional areas capable of managing stormwater, treating the pollutants present in the runoff, bringing back biodiversity to the urban environment, and providing amenity whilst improving livability. In this context, swales were studied as a potential multifunctional GSI for water management and energy saving. This research successfully proposed the combination of a wet swale with a Ground Source Heat Pump (GSHP) system. The materials used within the cross section of a standard wet swale provided good isolation properties within the temperature performance ranges (20–50 °C), showing great potential for a swale to be developed together with GSHP elements, opening a new research area for water management and energy saving.
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Chiovaro, P., S. Ciattaglia, F. Cismondi, A. Del Nevo, P. A. Di Maio, G. Federici, I. Moscato, G. A. Spagnuolo, and E. Vallone. "Assessment of DEMO WCLL breeding blanket primary heat transfer system isolation valve absorbed doses due to activated water." Fusion Engineering and Design 160 (November 2020): 111999. http://dx.doi.org/10.1016/j.fusengdes.2020.111999.

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Bolshakov, Nikolay Sergeevich, Sergey Aleksandrovich Krivoy, and Xeniya Mikhailovna Rakova. "The "Comfort in all Respects" Principle Implementation by the Example of an Elementary School." Advanced Materials Research 941-944 (June 2014): 895–900. http://dx.doi.org/10.4028/www.scientific.net/amr.941-944.895.

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The modern materials and technologies have an ability to provide a solution of the main goal of modern construction − maximum comfort. This article shows the implementation of comfortable building in a project of primary school. All the components of comfort have been taken under consideration: a rational space-planning, energy efficiency, acoustic isolation, air-tightness, daylight, fire safety, visual aesthetics. Special attention has been given to energy-efficiency: heat transfer coefficients have been calculated, optimal constructions have been selected, involving alternative methods of producing energy. The class of the building’s energy has also been determined. Economic benefits have also been described due to using renewable energy, area economy and so on. As a result, the concept of "comfort in all respects" have been revealed, recommendations on its implementation and further research in this area have been given.
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Fomina, E. V., V. S. Lesovik, and I. V. Lashina. "GAS CONCRETE FOR CONSTRUCTION OBJECTS OF TRANSPORT INFRASTRUCTURE." Russian Automobile and Highway Industry Journal 15, no. 5 (November 11, 2018): 774–86. http://dx.doi.org/10.26518/2071-7296-2018-5-774-786.

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Introduction.Construction objects of transport infrastructure have different influence and service conditions. An actual technical task is the design of optimal microclimate for human operation in workshops and office buildings. Therefore, such conditions can be achieved by using of construction material with high parameters of heat- and sound-insulation such as a gas concrete. The main task of the research is the improvement of heat- and sound-insulation in the gas concrete.Materials and methods.The evaluation of the gas concrete efficiency is based on the research of such parameters as heat- and sound-insulation. The analysis of the material at macro- and micro-level is performed with SEM-analysis and BET-analysis. In addition, the complex of experimental and calculated data of physical and chemical characteristics for gas concrete is carried out.Results.As a result, the usage of amorphous alum inosilicate raw materials in gas concrete allows variation of parameters to effect on pore structure such as homogeneous pore distribution in bulk, thickness and density of interpore partition, pore shape and pore size. The reduction of aerated concrete density by 22.5 % leads to reducing of heat conductivity by 19.26 %. The formation of cellular structure with mainly closed pores allows reducing of sorption humidity and vapor permeability of material under different environmental humidity.Differently-sized pores in the gas concrete and predominantly small pores with size of 0.3-0.9 mm as well as with size up to 94,6 nm leads to increasing isolation index of airborne sound due to increasing of absorption of acoustic wave in frequency range of 125-4000 Hz. Complexly, it provides high sound-insolating parameters of wall envelopes.Discussion and conclusions.Monitoring of heat- and sound-insolation of the gas concrete due to optimization of pore structure allows formation of energy effective composites able to protect humans from unfavorable environment in the transport enterprises.
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39

Skunca, Dubravka, Hedi Romdhana, and Rob Brouwers. "RUBISCO PROTEIN PRODUCTION – LCA APPROACH." MEST Journal 9, no. 1 (January 15, 2021): 175–83. http://dx.doi.org/10.12709/mest.09.09.01.20.

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The objective of this paper was to assess the environmental performance of the system of RuBisCo protein extraction and isolation from sugar beet leaves. Life cycle assessment (LCA) calculations have been completed to identify and quantify the environmental impacts from a cradle-to-cradle perspective covering seven subsystems: milling and extraction, heat treatment, centrifugation, microfiltration, ultrafiltration, chromatography and spray drying. In this paper, six environmental impact categories were analyzed: global warming potential, ozone layer depletion, energy demand, eutrophication potential, acidification potential, and land use. When RuBisCo protein extraction and isolation from different raw materials are compared, the only crop that has a lower environmental impact than sugar beet leaves is alfalfa, while the higher environmental impact has yellow mustard, ryegrass (mixture), Italian ryegrass, Brussels sprouts, English ryegrass, carrot leaves, leaf radish, and chicory. The comparison of environmental impact categories of different protein concentrates indicated that protein powder containing RuBisCo affected the environment less than egg protein concentrate. Direct comparison to other highly functional plant proteins was not possible as these are not in the market or have no LCA data available. RuBisCo was more environmentally impacting than regular soy protein. Our results for RuBisCo were in accordance with the low end of the range of results for microalgae, which is representing Chlorella HTF (heterotrophic fermenter), for most of the analyzed impact categories. This study found that the largest contributor to the environmental profile of the entire system of RuBisCo protein extraction and isolation from sugar beet leaves is the usage of electricity, while mitigation options for optimization of environmental impacts rely on the energy pinch approach for spray drying.
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Reilly, Aidan, Oliver Kinnane, and Richard O’Hegarty. "ENERGY EMBODIED IN, AND TRANSMITTED THROUGH, WALLS OF DIFFERENT TYPES WHEN ACCOUNTING FOR THE DYNAMIC EFFECTS OF THERMAL MASS." Journal of Green Building 15, no. 4 (September 1, 2020): 43–66. http://dx.doi.org/10.3992/jgb.15.4.43.

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ABSTRACT Embodied energy is a measure of the energy used in producing, transporting and assembling the materials for a building. Operational energy is the energy used to moderate the indoor environment to make it functional or comfortable—primarily, to heat or cool the building. For many building geometries, the walls make the most significant contribution to the embodied energy of the building, and they are also the path of greatest heat loss or gain through the fabric, as they often have a greater surface area than the roof or floor. Adding insulation reduces the heat flow through the wall, reducing the energy used during operation, but this adds to the embodied energy. The operational energy is not only a function of the wall buildup, but also depends on the climate, occupancy pattern, and heating strategy, making an optimisation for minimum overall energy use non-trivial. This study presents a comparison of typical wall construction types and heating strategies in a temperate maritime climate. The transient energy ratio method is a means to abstract the heat flow through the walls (operational energy for heating), allowing assessment of the influence of walls in isolation (i.e. in a general sense, without being restricted to particular building geometries). Three retrofit scenarios for a solid wall are considered. At very low U-values, overall energy use can increase as the embodied energy can exceed the operational energy; current best practice walls coupled with low building lifetimes mean that this point may be reached in the near future. Substantial uncertainty is present in existing embodied energy data, and given its contribution to total energy use, this is a topic of urgent concern.
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41

Salem, Jebreel M., and Dong Sam Ha. "A Resistive GaN-HEMT Mixer for a Cable Modem Operable up to 250°C for Downhole Communications." Journal of Microelectronics and Electronic Packaging 14, no. 1 (January 1, 2017): 17–25. http://dx.doi.org/10.4071/imaps.526.

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It is necessary for the oil and gas industry to drill deeper due to decrease of easily accessible natural reserves. Temperatures of deep wells can exceed 210°C, and conventional cooling and heat extraction techniques are impractical in such a harsh environment. Reliable electronic designs that can sustain high temperature become necessary. This article presents a high-temperature passive radio frequency (RF) mixer for downhole communications. The proposed mixer is designed to upconvert or downconvert the incoming signal with low conversion loss (CL), high linearity, and reliable operation at the ambient temperature up to 250°C. GaN is a wide-bandgap technology that can provide a reliable operation at high ambient temperatures, and the proposed mixer adopts a commercial GaN high-electron-mobility transistor. Measurement results indicate that the proposed mixer achieves a CL of 7.1 dB at local oscillator (LO) power of 2.5 dBm for the downconversion from 230–253 to 97.5 MHz at 250°C and the input P1dB compression point lies at 5 dBm. The designed mixer also achieves 24.5 dB RF-to-intermediate frequency (IF) isolation and 28 dB LO-to-IF isolation at 250°C. The power dissipation of the mixer is virtually zero.
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42

Terenteva, N. A., E. K. Psareva, N. F. Timchenko, V. A. Golotin, and V. A. Rasskazov. "EFFECT OF YERSINIA PSEUDOTUBERCULOSIS TOXINS ON THE BIOFILM FORMATION." Journal of microbiology epidemiology immunobiology, no. 6 (December 28, 2017): 37–42. http://dx.doi.org/10.36233/0372-9311-2017-6-37-42.

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Aim. To study the effect of heat-labile (HLTY) and heat-stable (HSTY) lethal toxins of the of Yersinia pseudotuberculosis on the formation of biofilms by these bacteria. Materials and methods. For the isolation of toxins and the investigation their ability to effect on the biofilm formation there were used the strain of Y. pseudotuberculosis 512 (pYV48Mjl. рУМ82МД) and strain 2517, carrying virulence plasmid pYV and lost it, correspondingly. Results. The stimulation of biofilm formation at 20°C by the strain 2517 (pYV+), carrying virulence plasmid as well as the strain 2517 (pYV-) without plasmid were observed In the presence of HLTY. At low positive temperature (6 - 8°C) HLTY reduces the amount of the formed biofilm. HSTY inhibited the biofilm formation by the both strains of Y. pseudotuberculosis tested during the incubation for 3 days at 20°C and 6 - 8°C. Moreover the extent of inhibition was decreased with temperature decreasing. Conclusion. The both of the Y. pseudotuberculosis protein toxins has been revealed to affect on the biofilm formation by Y. pseudotuberculosis bacteria, however, the impact of HLTY and HSTY in the processes of biofilm formation was shown to be different, and the mechanism of such action of toxinsis under way.
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43

Sun, Christine (Qin), Dong Zhang, Larry C. Wadsworth, and Mac McLean. "Development of Innovative Cotton-Surfaced Nonwoven Laminates." Journal of Industrial Textiles 31, no. 3 (January 2002): 179–88. http://dx.doi.org/10.1106/152808302026111.

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Cotton-based nonwovens have been developed at Textiles and Nonwovens Development Center (TANDEC), The University of Tennessee, with the cotton fibers on the surface or in the core layer laminated with meltblown (MB) and/or spunbonded (SB) webs. Both Cotton-Surfaced Nonwovens (CSN) and Cotton-Core Nonwovens (CCN) have excellent soft hand, breathability, absorbency, and tensile properties making them ideal for many medical applications such as isolation gowns, hospital drapes and gowns, shoe covers, head covers, underwear, pillowcases, diaper components (acquisition, core, back sheet), feminine hygiene pads, baby wipes, etc. In this paper, the processes to produce these cotton-surfaced nonwovens will be presented, including as-bonded, heat-stretched CSN fabrics, and foam-finished CSN nonwovens.
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44

SOCKALINGAM, KANAGESWARY, Mohd Azha Yahya, and Hasan Zuhudi Abdullah. "Preparations of Hydroxyapatite from Tilapia Scales." Advanced Materials Research 1087 (February 2015): 30–34. http://dx.doi.org/10.4028/www.scientific.net/amr.1087.30.

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Hydroxyapatite (HAp), classified as bioceramic materials is the major mineral constituent of vertebrate bones and teeth. In this study, the effect of temperature on isolation and characterization of HAp from tilapia fish scales have been investigated. Scales were subjected to heat treatment at different temperatures (800°C and 1000°C) and microstructure of both raw and calcined scales were observed under Scanning Electron Microscopy (SEM). Thermo Gravimetric Analysis (TGA) and Energy Dispersive X-Ray Spectroscopy (EDX) results have revealed the best calcination temperature of tilapia scales to be 800°C due to the calculated calcium to phosphorous weight ratio (Ca/P). The Ca/P ratio for scales treated at 800°C and 1000°C were 1.598 and 1.939 respectively. The phase purity and crystallinity of produced HAp was further confirmed by X-Ray Diffraction (XRD) analysis. Based on the study, it can be concluded that tilapia fish scale is a good natural source of HAp with 800°C as the optimum calcination temperature in HAp production.
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45

Di Lonardo, Sara, Susanna Mariani, Germina Giagnacovo, Antonella Marone, and Salvatore Raimondi. "Green infrastructures for the energetic and environmental sustainability of cities." RIVISTA DI STUDI SULLA SOSTENIBILITA', no. 2 (January 2020): 79–98. http://dx.doi.org/10.3280/riss2019-002-s1006.

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The inexorable extension of urbanization is consuming huge amounts of soil drastically reducing natural vegetation, replacing it with buildings and low albedo surfaces. The changes due to the different thermal properties of surface materials and the lack of evapotranspiration in urban areas lead to a phenomenon known as "urban heat island effect". By reintroducing the vegetation back into the urban landscape, a partnership between nature and cities should be strengthened to create a new sustainable urban environment. Since the outer surfaces of building offer a great amount of space for vegetation, planting on roofs and walls has become one of the most innovative way to provide several environmental services. Moreover, all the green infrastructures, such as urban gardens or nature areas, that form an important part of cityscapes, could ensure also a thermal isolation and constitute a sustainable energy saving solution for buildings. This work presents a critical review of environmental and potential thermal benefits of green infrastructures in the cities.
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46

Bratasyuk, N. A., Ya A. Tsyblenko, and K. O. Osetrov. "Design peculiarities of sealing joints for cable penetrators." Transactions of the Krylov State Research Centre S-I, no. 2 (December 21, 2021): 44–52. http://dx.doi.org/10.24937/2542-2324-2021-2-s-i-44-52.

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The purpose of this work is to describe and summarize main design principles of sealing joints for cable penetrators of deepwater vehicles. The study was performed on typical sealed areas of watertight cable penetrators, like soldered joint between copper sheath of a heat resistant cable with mineral isolation (KMZh) and cable penetrator body; polymeric termination of cable ends; sealing joint of metal penetrator body in pressure hull with circular elastomeric gaskets. The case study in this paper is a metal casing attached to KMZh cable by a heat-resistant silverized brazing alloy. The quality of soldering joints was estimated metallographically, i.e. by means of optical microscopy and electronic raster spectroscopy. Watertightness of KMZh cable is ensured by reactoplast-based polymers that must be not only adequate to their operational conditions but also comply with fire safety regulations for ships. Watertightness of penetrator interface with pressure hull is achieved by means of elastomeric gaskets. The study investigated main sealing joints of penetrators, as well as the mechanisms achieving watertightness of each given joint. Analysis in ANSYS software package yielded the optimal thermal scenario of casing warm-up offering the best quality of both soldering process and adhesion to the KMZh cable. The calculation was also performed for the minimum length of brazed joint of constant width so as to ensure strength and watertightness at different external pressures. Calculation results were performed by hydraulic tests of penetrator samples. The study also identified the peculiarities of polymeric sealant selection. A promising approach for cable termination manufacturing would be to use heat-resistant materials featuring shape memory effect.
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47

Winkler, Wolfgang. "Fuel Cell Hybrids, Their Thermodynamics and Sustainable Development." Journal of Fuel Cell Science and Technology 3, no. 2 (August 29, 2005): 195–201. http://dx.doi.org/10.1115/1.2174069.

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The increasing demand on primary energy and the increasing concern on climatic change demand immediately a sustainable development, but still there remain open questions regarding its technical realization. The second law of thermodynamics is a very simple but efficient way to define the principle design rules of sustainable technologies in minimizing the irreversible entropy production. The ideal, but real process chain is defined by a still reversible structure or logic of the process chain—the reversible reference process chain—but consisting of real components with an irreversible entropy production on a certain level. It can easily be shown for energy conversion and for transportation that hybridization in general can indeed be a measure to meet the reversible process chain and to minimize the entropy flow to the environment. Fuel cells are principal reversible converters of chemical energy and thus a key element within hybridization. Depending on application, combined heat and power process (CHP) may be a hybridization step or only a slight improvement. There is a fundamental difference in heating a house or in supplying an endothermic chemical reaction with reaction entropy. The use of heat recovery and isolation is a necessary measure to minimize the entropy flow to the environment and can be described by a reversible reference process as well. The application of reversible reference process chains shows that hybrid systems with fuel cells are a technical feasibility to approach very closely the thermodynamic potential. This development differs from the past where the technical possibilities of materials and manufacturing limited the technology to meet reversibility and thus sustainability.
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48

Sablii, Larysa, Oleksandr Obodovych, Vitalii Sydorenko, and Tamila Sheyko. "Study of wheat straw delignification in a rotary-pulsation apparatus." Acta Periodica Technologica, no. 51 (2020): 103–10. http://dx.doi.org/10.2298/apt2051103s.

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This paper presents the results of studies of isolation lignin and hemicelluloses efficiency during the pre-treatment of wheat straw for hydrolysis in a rotary-pulsation apparatus. The pre-treatment of lignocellulosic raw materials for hydrolysis is a necessary step in the second-generation bioethanol production technology. The lignocellulose complex is destroyed during this process, and this allows hydrolytic enzymes access to the surface of cellulose fibers. The pre-treatment is the most energy-consuming stage in bioethanol production technology, since it usually occurs at high temperature and pressure for a significant time. One of the ways to improve the efficiency of this process is the use of energy-efficient equipment that allows intensifying heat and mass transfer. An example of such equipment is a rotary-pulsation apparatus, which are effective devices in stirring, homogenization, dispersion technologies, etc. The treatment of wheat straw in a rotary-pulsation apparatus was carried out under atmospheric pressure without external heat supply at solid/water ratios of 1:10 and 1:5 in the presence of alkali. It was determined that the treatment of the water dispersion of straw at ratio of 1:10 due to the energy dissipation during 70 minutes leads to the release of 42 % of lignin and 25.76 % of easily hydrolyzed polysaccharides. Changing the solid / water ratio from 1:10 to 1:5 leads to an increase in the yield of lignin and easily hydrolyzed polysaccharides to 58 and 33.38 %, respectively.
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Barad, Chen, Giora Kimmel, Hagay Hayun, Dror Shamir, Kachal Hirshberg, and Yaniv Gelbstein. "Phase Stability of Nanocrystalline Grains of Rare-Earth Oxides (Sm2O3 and Eu2O3) Confined in Magnesia (MgO) Matrix." Materials 13, no. 9 (May 11, 2020): 2201. http://dx.doi.org/10.3390/ma13092201.

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Rare-earth (RE) oxides are important in myriad fields, including metallurgy, catalysis, and ceramics. However, the phase diagram of RE oxides in the nanoscale might differ from the phase diagrams for bulk, thus attracting attention nowadays. We suggest that grain size in the nanoscale also determines the obtained crystallographic phase along with temperature and pressure. For this purpose, nanoparticles of Sm2O3 and Eu2O3 were mixed in an inert MgO matrix via the sol-gel method. This preparation method allowed better isolation of the oxide particles, thus hindering the grain growth process associated with increasing the temperature. The mixed oxides were compared to pure oxides, which were heat-treated using two methods: gradual heating versus direct heating to the phase transition temperature. The cubic phase in pure oxides was preserved to a higher extent in the gradual heating treatment compared to the direct heating treatment. Additionally, in MgO, even a higher extent of the cubic phase was preserved at higher temperatures compared to the pure oxide, which transformed into the monoclinic phase at the same temperature in accordance with the phase diagram for bulk. This indicates that the cubic phase is the equilibrium phase for nanosized particles and is determined also by size.
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Kravets, I. P., O. I. Bashynskiy, A. P. Kushnir, and O. V. Shapovalov. "FACTORS OF FIRE HAZARD OF ELECTRICITY-GENERATING EQUIPMENT." Fire Safety, no. 34 (July 19, 2019): 43–46. http://dx.doi.org/10.32447/20786662.34.2019.07.

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Abstract:
The article deals with the problems of fire hazard of electricity-generating equipment during their exploitation. Intensive electrification of industrial and residual objects leads to the saturation of these objects with different electricity-generating equipment. Functioning of such equipment is accompanied with high heat emission and contains significant fire hazard. The electric current in an electrical conductor produces heat, when electric energy turns into thermal. All electrical equipment must be produced in strict adherence to fire safety rules and requirements. Ignoring these requirements causes heating of conductors through all the length, spunking of isolation, sparkling and, as a result, breaking-out of fire. Therefore, reducing the probability of fire even in the cases of abnormal work, wrong exploitation and foreseen refuses is the main task during planning and exploitation of electrical equipment and also during selection of structural materials. The primary purpose of fire prevention measures in the electrical equipment is avoiding of its self-ignition, and localization of fire after the self-ignition of electricity-generating equipment. Fire safety during exploitation of electricity-generating equipment depends on its technical state. Correct choice of conductor cross section is very important. Protection stage of electrical equipment, type of wiring, and cable laying method must comply with environmental conditions and have the proper climatic implementation and placement category. Proper protective devices from a short circuit and overloads must be used. Their operating values must be also foreseen. All above-mentioned measures prevent fires and explosions during exploitation of electrical equipment. Key
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