Rashid A. Saeed¹, Mamoon M. Saeed^2,3, Rania A. Mokhtar¹, Hesham Alhumyani¹, S. Abdel-Khalek^4,*

Computer Systems Science and Engineering, Vol.39, No.1, pp. 1-14, 2021, DOI:10.32604/csse.2021.015593

Abstract Privacy, identity preserving and integrity have become key problems for telecommunication standards. Significant privacy threats are expected in 5G networks considering the large number of devices that will be deployed. As Internet of Things (IoT) and long-term evolution for machine type (LTE-m) are growing very fast with massive data traffic the risk of privacy attacks will be greatly increase. For all the above issues standards’ bodies should ensure users’ identity and privacy in order to gain the trust of service providers and industries. Against such threats, 5G specifications require a rigid and robust privacy procedure. Many research studies have addressed… More >

Khaldoon M. Alhyasat^1,*, Kamarulzaman Ibrahim¹, Amer Al-Omari², Mohd Aftar Abu Bakar¹

Computer Systems Science and Engineering, Vol.39, No.1, pp. 55-67, 2021, DOI:10.32604/csse.2021.014909

Abstract In this paper, the Rama distribution (RD) is considered, and a new model called extended Rama distribution (ERD) is suggested. The new model involves the sum of two independent Rama distributed random variables. The probability density function (pdf) and cumulative distribution function (cdf) are obtained and analyzed. It is found that the new model is skewed to the right. Several mathematical and statistical properties are derived and proved. The properties studied include moments, coefficient of variation, coefficient of skewness, coefficient of kurtosis and moment generating function. Some simulations are undertaken to illustrate the behavior of these properties. In addition, the… More >

Yong Wang, Yongyan Wang^*, Nan Qin, Sa Huang, Le Chang, Shunzheng Hou

Computer Systems Science and Engineering, Vol.39, No.1, pp. 121-131, 2021, DOI:10.32604/csse.2021.014464

Abstract The work presented in this paper was conducted to quantify the relationship between the pore characteristics and mechanical properties of white sandstone. The study include tests carried out under the coupling effects of chemical corrosion, temperature, nuclear magnetic resonance, and mechanical tests. Computer fractal theory was employed to describe and quantify the characteristics of the growth of pores in white sandstone under the same coupling effect. A custom developed program code, in the MATLAB software platform, was used for calculating the growths of the pores in white sandstone when subjected to coupling effects. The correlation between the computer fractal dimension… More >

Lei Tan, Liangxian Liu, Chaodong Liu, Weihong Wang^*

Journal of Renewable Materials, Vol.9, No.11, pp. 1897-1911, 2021, DOI:10.32604/jrm.2021.016418

Abstract As the most favorable alternative to petroleum-based polymers, polylactic acid (PLA) which is the most promising degradable polymer has attracted increasing attention. However, the addition of cellulose to improve its strength often results in a reduction in its toughness. In this work, microscale cellulose is first prepared from pulp fibers by using a deep eutectic solvent, and then is used as the reinforcement of PLA. A microcrystalline cellulose (MCC)/PLA sheet with uniform texture is obtained by the solution mixing, melt blending, hot-pressing and cold-pressing process. The effects of MCC on the crystallization, thermal stability and mechanical properties of the PLA… More >

Zhigang Wu^1,#, Sicheng Chen^1,#, Jiankun Liang², Lifen Li¹, Xuedong Xi^3,4, Xue Deng¹, Bengang Zhang^3,*, Hong Lei^4,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1959-1972, 2021, DOI:10.32604/jrm.2021.016786

Abstract Alkali lignin was processed by plasma and then used in modification of phenol formaldehyde resin in this study. Chemical structural changes of lignin which was processed by plasma as well as bonding strength, tensile property, curing performance and thermal property of the prepared phenol formaldehyde resin which was modified by the plasma processed lignin were analyzed. Results demonstrated that: (1) Alkali lignin was degraded after the plasma processing. The original groups were destroyed, and the aromatic rings collected abundant free radicals and oxygen-containing functional groups like hydroxyls, carbonyls, carboxyls and acyls were introduced into increase the reaction activity of lignin… More > Graphic Abstract

Xiaohua Gu^1,*, Shiwei Lyu¹, Siwen Liu²

Journal of Renewable Materials, Vol.9, No.11, pp. 1913-1926, 2021, DOI:10.32604/jrm.2021.015400

Abstract A bi-component alcoholysis agent containing propylene glycol (PG) and ethanolamine (ETA) was used to catalyst the degradation of the waste polyurethane rigid foam. The oligomer polyols obtained through degradation were used as raw materials to produce recycled polyurethane rigid foam composites with lignin as reinforcing filler. The effect of alcoholysis mass ratio on degradation was investigated by analyzing the viscosity, hydroxyl content and chemical structure of the degradation products. The effect of lignin addition on the properties of regenerated polyurethane rigid foam were investigated by analyzing water absorption rate, compressive strength, porosity, thermal stability, thermal conductivity coefficient, morphology and thermal… More >

Nataša Knez¹, Mirko Kariž², Friderik Knez¹, Nadir Ayrilmis^3,*, Manja Kitek Kuzman^2,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1883-1895, 2021, DOI:10.32604/jrm.2021.016128

Abstract The effects of selected printing parameters on the fire properties of additively produced composites from neat polylactic acid (PLA) and wood/PLA filaments were investigated. The reaction to fire of the 3D-printed specimens was tested according to the ISO 5660-1 cone calorimeter test method. The results showed that the properties of the specimens when exposed to fire were significantly affected by the incorporation of wood flour into the PLA filament. It was also interesting that PLA specimens had much better reactions to fire than the wood/PLA specimens. Time to ignition was found to be much longer in the 3D-printed PLA specimens.… More >

Christian Brütting¹, Julia Dreier², Christian Bonten², Volker Altstädt¹, Holger Ruckdäschel^1,*

Journal of Renewable Materials, Vol.9, No.11, pp. 1859-1868, 2021, DOI:10.32604/jrm.2021.016244

Abstract Polylactide (PLA) bead foams show a high potential regarding their applicability in packaging or consumer products. Concerning the comparable properties of PLA to Polystyrene (PS) and the good CO₂ footprint it represents a potential alternative to petroleum-based polymer foams. However, foaming of PLA is challenging, due to its low melt strength, therefore chemical modifiers are often used. Concerning the bead foam technology regarding PLA, the available literature is limited so far. Within this study, the bead foaming behavior of neat and modified amorphous PLA was investigated. The material was modified by talc and an epoxy-based chain extender. These compounds have… More >

M. A. F. A. Wahab¹, S. M. Sapuan^1,2,*, M. M. Harussani¹, M. Y. M. Zuhri¹, A. A. Saleh³

Journal of Renewable Materials, Vol.9, No.11, pp. 1973-1989, 2021, DOI:10.32604/jrm.2021.016221

Abstract This paper presents the development process relating to the conceptual design of glass/renewable natural fibrereinforced polymer hybrid composite motorcycle side cover. Motorcycle side cover is a component frequently made from plastic or steel that functions on covering the motorcycle parts, components and systems such as frame, battery, electrical systems and mechanical systems. Function Analysis Systems Techniques (FAST) is used to identify the functions of motorcycle side cover. The right-side cover of motorcycle model SYM E-Bonus 110 has been physically studied to identify the competitive benchmarking criteria. The functions and competitive benchmarking criteria are then compiled and integrated with the environmental… More >

Enas H. Ali, Juman A. Naser^*, Zainab W. Ahmed, Taki A. Himdan

Journal of Renewable Materials, Vol.9, No.11, pp. 1927-1939, 2021, DOI:10.32604/jrm.2021.015624

Abstract Polymeric nanofibers are a promising technology to protect the metal surfaces from corrosion. Through the literature search, the use of polyacrylonitrile nanofibres (PANNFs) as a corrosion inhibitor coating for aluminum alloys has not been evaluated. This work includes the development of a new, lightweight, high surface area and efficient coating of PANNFs that produced using electrospinning process to resist the corrosion of aluminum alloys (AA5083) which immersed in 0.6 M NaCl at alkaline medium (pH = 12) and acidic medium (pH = 1) at a range of temperatures (293–323) K. The PANNFs coating was successfully deposited on AA 5083 specimens,… More >