Yong-Woon Hwang, Im-Yeong Lee^*

CMC-Computers, Materials & Continua, Vol.69, No.2, pp. 1747-1764, 2021, DOI:10.32604/cmc.2021.018549

Abstract Recently, with the advancement of Information and Communications Technology (ICT), Internet of Things (IoT) has been connected to the cloud and used in industrial sectors, medical environments, and smart grids. However, if data is transmitted in plain text when collecting data in an IoT-cloud environment, it can be exposed to various security threats such as replay attacks and data forgery. Thus, digital signatures are required. Data integrity is ensured when a user (or a device) transmits data using a signature. In addition, the concept of data aggregation is important to efficiently collect data transmitted from multiple users (or a devices)… More >

Yong Wang, Yongyan Wang^*, Songmei Li, Nan Qin, Peng Du, Tongtong Zhou

Computer Systems Science and Engineering, Vol.39, No.2, pp. 179-195, 2021, DOI:10.32604/csse.2021.014469

Abstract The antiknock capability and thermal protection performance of rescue capsules mainly depend on the structural design of the cabin. By designing a new type of cabin structure, it can resist the impact of explosion shock waves and thermal shocks. In this paper, a new honeycomb-like cabin is proposed; the model has a novel thermal insulation layer design. Then, the antiknock capabilities and thermal protection analysis are carried out by using computer software. The “Autodyn” analysis module in ANSYS Workbench 17.0 has been used to simulate the explosion of TNT with a certain quality in a single room. The pressure map… More >

Jie Chen¹, Wei Zhang¹, Man Ding^2,*, Libin Hu¹, Jinpeng Wang², Chenying Li¹, Jingying Cao¹

Energy Engineering, Vol.118, No.5, pp. 1537-1548, 2021, DOI:10.32604/EE.2021.015439

Abstract The aging characteristics of the XLPE insulation of 110 kV power cables in the initial stage of operation are studied in this paper. The XLPE insulation from cables with different running time was tested by using electrical and physicochemical methods, from which the degradation state of XLPE under multiple stresses during operation was derived. The broadband dielectric spectrum test taken from 10^–1 to 10⁶ Hz showed that the dielectric constant and dielectric loss of the XLPE insulation first decrease and then increase with the increase of cable running time, which show obvious variation until 10 years of operation. The AC… More >

Yujie Huang¹, Hao Zhu², Dauletbek Assima⁴, Zheng Wang^1,*, Minmin Li³, Xinyue Zhao¹

Journal of Renewable Materials, Vol.9, No.4, pp. 829-840, 2021, DOI:10.32604/jrm.2021.014610

Abstract To improve the impact sound insulation performance of building floors and meet the objective requirements for living comfort of residents, in this article, three kinds of elastic cushion materials, Portuguese cork board, BGL insulation sound insulation foam board, and EPP polypropylene plastic foam board, are applied to the sound insulation of a light frame wood floor structure of the same bedroom and compared to the ordinary floor. This study uses the transfer function method and transient excitation method to measure the sound insulation, damping ratio, and elastic modulus of materials, as well as the sound insulation of the floor under… More >

Abdelsalam Aldawoud^*, Fatma Elzahraa Hosny, Rasha Mdkhana

Energy Engineering, Vol.117, No.6, pp. 381-395, 2020, DOI:10.32604/EE.2020.011863

Abstract The opportunities for energy savings by retrofitting of the existing school buildings in the United Arab Emirates (UAE) are significant because of their excessive energy consumption and space cooling demand. In this research, energy modeling and simulation are utilized with the use of Design Builder software to examine the influence of various retrofitting measures of air-conditioning (A/C) system and building envelope components on the energy use. Several combined measures are implemented and assessed to achieve the main goal of this research of selecting the best course of action to reduce cooling energy consumption for existing school buildings in the UAE.… More >

Shihao Fan, Mingliang Chang^*, Shouxi Wang, Qing Quan, Yong Wang, Dan Li

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 45-59, 2020, DOI:10.32604/cmes.2020.08973

Abstract It is important to determine the insulation thickness in the design of the buried hot oil pipelines. The economic thickness of the insulation layer not only meets the needs of the project but also maximizes the investment and environmental benefits. However, as a significant evaluation, the environmental factors haven’t been considered in the previous study. Considering this factor, the mathematical model of economic insulation thickness of the buried hot oil pipelines is built in this paper, which is solved by the golden section method while considering the costs of investment, operation, environment, the time value of money. The environmental cost… More >

M. Čekon^*, K. Struhala, R. Slávik

Journal of Renewable Materials, Vol.5, Suppl.1, pp. 84-93, 2017, DOI:10.7569/JRM.2017.634135

Abstract Cardboard-based packaging components represent a material that has significant potential as a renewable source for exploitation in buildings. This study presents the results of thermal and environmental analyses of existing packaging materials compared with standard conventional thermal insulations.
Experimental measurements were performed to identify the thermal performance of studied cardboard packaging materials. Real-size samples were experimentally tested in laboratory measurements. The thermal resistance and conductivity of all the analyzed samples were measured according to the procedure indicated in the ISO8032 standard. A life-cycle assessment according to ISO 14040 was also performed to evaluate the environmental impacts related to the… More >

Qingfang Lv^1,*, Weiyang Wang¹, Ye Liu¹

Journal of Renewable Materials, Vol.7, No.11, pp. 1231-1250, 2019, DOI:10.32604/jrm.2019.08345

Abstract In recent years, bamboo, as a green building material, has attracted more and more attention worldwide. Inspired by the investigation of cross-laminated timber in structural systems, a new engineered cross-laminated bamboo (CLB) consisting of the cross lamination of bamboo scrimber plates is proposed in this paper. To evaluate its potential in structural applications, the thermal insulation performances of the CLB walls and CLB walls with the EPS foam plate were studied and evaluated by the temperature-controlled box-heat flow meter method. Test results indicated that the thermal insulation performance improved with the increase of thickness, but different wall configurations had little… More >

Dounia Bendahou^1,2, Abdelkader Bendahou¹, Bastien Seantier¹, Bénédicte Lebeau³, Yves Grohens^1,*, Hamid Kaddami^2,*

Journal of Renewable Materials, Vol.6, No.3, pp. 299-313, 2018, DOI:10.7569/JRM.2017.634185

Abstract Hybrid aerogels have been prepared by freeze-drying technique after mixing water dispersions of cellulose microfibers or cellulose nanofibers and silica (SiO2) of type SBA-15 (2D-hexagonal). The prepared composites were characterized by different analysis techniques such as SEM, hot-filament, DMA, etc. These composites are compared to those previously prepared using nanozeolites (NZs) as mineral charge. The morphology studied by SEM indicated that both systems have different structures, i.e., individual fibers for cellulose microfibers WP-based aerogels and films for nanofibrillated cellulose NFC-based ones.... These differences seem to be driven by the charge of the particles, their aspect ratio and concentrations. These hybrid… More >

M. Himabindu¹, K. Kamalakar², MSL Karuna², Aruna Palanisamy^1*

Journal of Renewable Materials, Vol.5, No.2, pp. 124-131, 2017, DOI:10.7569/JRM.2016.634137

Abstract Rigid polyurethane biofoams were prepared from karanja polyol which was derived by ring-opening reaction of epoxidized karanja oil. The polyol, which had a hydroxyl value of 186 mg KOH/g, was thoroughly characterized and the structure confirmed by spectral techniques. The foam formulations were developed to achieve shrinkage-free foams with water used as the blowing agent. The resulting foams were characterized for their mechanical properties like density, compression strength and flexural strength. The densities and mechanical properties, such as compression and flexural strength, varied with the amount of methylene diphenyl diisocyanate (MDI) for a fixed amount of polyol and other additives… More >