Issue 7

Adaptations and Lessons from COVID-19: A Perspective on How some Industries will be Impacted

Amar Velic; Alka Jaggessar; Senevirathne Wickramasooriya Mudiyanselage Amal Ishantha Senevirathne; Asha Mathew; Phani Kumari Paritala; Majedul Islam; Arpana Gopi Panicker; Karthika Prasad; Tejasri Yarlagadda; Kirsten Spann; Jafar Hasan; Prasad KDV Yarlagadda

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-7
DOI: 10.5185/amlett.2020.071533

Since the advent of the novel coronavirus disease (COVID-19), various industrial sectors have been significantly affected. Considering the widespread threat of the SARS-CoV-2 virus, scientists worldwide have been working at a rapid pace to understand the virus, develop vaccines and find possible treatment options. Drastic public health measures such as social distancing, use of PPE, quarantine and complete lockdown have been implemented globally to minimize the spread of the virus. Whilst these measures currently seem the only plausible option, they come at the price of compromised economies. Though there are many collaterally affected industries, this review paper highlights current and forecasted changes in manufacturing, medical, climate change, energy and food processing sectors. Some of these sectors have been positively impacted, such as climate change, whilst others have experienced mixed consequences. Some also face an uphill rebuilding processes, which needs to begin sooner rather than later. This paper highlights important recent developments and perspectives on how industries may adapt and learn from COVID-19.  

Background and Strategies for Identification and Design of Materials for Thermochemical Energy Storage and Conversion

Sandra Afflerbach; Wolfgang Krumm; Reinhard Trettin

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-7
DOI: 10.5185/amlett.2020.071534

Within the past decade, ecological issues accompanying energy generation and utilization have gained increasing interest, thereby creating a need for new scientific and technical solutions on the path to a sustainable energy future. Besides switching the basis of the electricity sector from fossil fuels to renewables, also the heat sector is to be transformed. A major obstacle accompanying this energy transition is the temporal intermittency of power generation from renewables. However, these hurdles can be overcome by design of systems for energy storage and conversion. Within the growing field of solutions for thermal storage, thermochemical systems move into the focus as they provide comparably highest storage densities but at the same time also options for heat conversion. This concise review summarizes the background and the scope of possible applications discussed in recent literature. A focus is set on the identification and modification of new reaction systems, criteria for material selection are presented and different classes of reaction systems are discussed with regard to their operating temperature ranges. It is concluded, that an evaluation of possible use cases with precise definition of their respective thermal boundary conditions would be of high value for a purposeful continuation of future screening approaches.

Phosphorus Gasification during the Reduction of basic Oxygen Furnace Slags in a Novel Reactor Concept

Christoph Ponak; Valentin Mally; Stefan Windisch; Alexandra Holzer; Harald Raupenstrauch

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-7
DOI: 10.5185/amlett.2020.071535

The research presented in this publication focuses on the removal of phosphorus from basic oxygen furnace slags via the gas phase during carbo-thermal reduction in a bed of inductively heated graphite pieces. Its purpose is to evaluate the effect of the application of a novel reactor concept on the possibilities of phosphorus gasification. The slags are processed in two steps during the experimental trial: First, a silica source is added to reduce the basicity of the slag. In a second step, the actual reduction process is conducted at reaction temperatures of 1,623 K, 1,773 K and 1,923 K, respectively. The molten slag forms a film moving down the reactor with minimal contact time between iron (l) and phosphorus (g) so that a high amount of phosphorus gas can be removed from the reactor. The most important results are that more than 95% of the phosphorus contained in the slags could be reduced, roughly 85% of which were removed via the gas phase. Virtually iron-, chromium- and phosphorus-free slags are obtained. It is concluded that the application of the presented reactor concept based on thermodynamic evaluations potentially tackles the challenges posed by the reaction behaviour of phosphorus.

Concrete Electrical Resistivity at Varied Water, Chloride Contents and Porosity – Experiment, Modelling & Application

Yu Wang; Hayder Oleiwi; Nan Xiang

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-4
DOI: 10.5185/amlett.2020.071536

Understanding and characterizing the relationship between the electrical resistivity and the major influencing factors of the concrete have been all the time a topical research in relation to structural durability. This paper reports an experimental study on the influences of water and chloride contents, and porosity on the electrical resistivity of the Portland cement concrete. The results indicate that the electrical resistivity has a strong correlation with the water and chloride contents in concrete. A new characteristic model has been proposed to represent the correlation. The proposed model has been implemented into a numerical modelling case study of cathodic protection for reinforced concrete structure in saline environment.

Water Purifying Bio-concrete

Rajiv Gupta

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-5
DOI: 10.5185/amlett.2020.071537

Water is the quintessential element of life. In the arid zones like Rajasthan, India, rainfall is scanty and ground water table is too low to satisfy the needs of living beings. One of the water sources is harvesting rain. Though the rainwater does not have its own contaminants but when it touches the surface, it gets contaminated (physically, chemically and biologically). The water thus harvested is used for drinking/ domestic purposes. Drinking water need to be freed from microbial/ disease. Literature indicates the usage of bacteria for self-healing concrete but no study indicates the use of bacteria, Bacillus Licheniformis (BL) or Bacillus Subtilis (BS), for the purification of water. These bacteria can survive high temperatures and can exist in spore form to resist harsh environments or in a vegetative state when conditions are good. In present study two bacteria BL and BS are tested. These bacteria feed on the organic contaminants present in water and produce harmless end products. Cultured bacteria are mixed in concrete to make slabs or sprayed on plain slabs with different combinations. The efficiency is analysed by testing the polluted water samples before and after passing through the slab. Results indicate that water is potable.

Local Fluctuations of Transformation to “Amorphous Diamond” from C60 Fullerenes and Neutron-irradiated Graphite under Shock-compression

Keisuke Niwase

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-5
DOI: 10.5185/amlett.2020.071538

C60 fullerene and neutron-irradiated graphite have been reported to directly transform into “amorphous diamond” under shock compression, but the transformation mechanism is still not clear. Here, we report local fluctuations in the transformation to “amorphous diamond” from C60 fullerene and neutron- irradiated highly oriented pyrolytic graphite shock-compressed at 52 and 51 GPa respectively. For the platelets recovered from C60 fullerene film after the shock-compression, we observed a small Raman peak of diamond, of which peak shape changes depending on the area of platelets. Peak fitting revealed that the diamond Raman peak shifts to lower frequency with increasing the peak width and decreasing the peak intensity. This corresponds to the decrease of the crystalline size of nano-crystalline diamond and indicates the existence of amorphous diamond at an area where the intensity of diamond peak vanished. For the recovered sample of neutron-irradiated highly oriented pyrolytic graphite, on the other hand, we found an appearance of domain boundary between optically transparent and opaque areas, which respectively correspond to transformed and untransformed areas, thereby suggesting some novel transformation process originated in the initial disordered structure

Coulomb Drag of Electron-Electron Interactions in GaAs Bilayer with a Non Homogeneous Dielectric Background

Sharad Kumar Upadhyay; L. K. Saini

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-5
DOI: 10.5185/amlett.2020.071539

Motivated by recent studies in multilayer system of dielectric background, we analytically studied the coulomb drag effect in hetero-junction of GaAs system, which consist a non-homogeneous dielectric background. By considering the weak interaction in static case, the effective dielectric function is evaluated by using Random Phase Approximation (RPA) method as RPA is a reliable study for high density regime. The effective coulomb interaction cause of electron-electron interaction in the Boltzmann regime and at low temperature limit is considered. Dependency of layer separation is effectively described by local form factor has been taken into account in effective dielectric function, the local form factor is obtained from the solution of the Poisson equation of a three-layer dielectric medium with GaAs sheets. Drag resistivity is measured numerically and analytically, where temperature and density dependence are investigated and compared to 2DEG-2DEG double-layer structures theoretically and experimentally at very low temperature.

Effect of Nd-concentration in Nd(2-x)FexO3 System on the Crystal Structure and Microwave Absorption Characteristics

Wisnu Ari Adi

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-4
DOI: 10.5185/amlett.2020.071540

Effect of Nd-concentration in Nd(2-x)FexO3 system on the structure and microwave absorption characteristics have been studied. Nd(2-x)FexO3 system is one of perovskite based system which has a relative high permittivity. Nd(2-x)FexO3  (x=0.5; 1.0 and 1.2) samples were synthesized by Fe(NO3)3 and Nd(NO3)3 in mole ratio using sol–gel method and then sintered at 800°C for 5 hours. All of the samples were characterized using XRD to identify the phase, SEM to observe the morphology and VNA was used to measure the microwave absorption. Phase identification of XRD data shows that single phase of NdFeO3 have been formed for x = 1.0 composition (ABO3). While multiphase have been formed which is indicated by the appearance of NdFeO3 and Nd2O3 phase for x = 0.5, and then NdFeO3 and Fe2O3 phase for x = 1.2. SEM image shows the samples of Nd(2-x)FexO3 have homogenous morphology with particle size is approximately 200 nm. The results of microwave absorbing properties measured by using VNA (Vector Network Analyzer) shows the best ability of microwave absorption is x = 1.0 composition is around 96.27% at frequency of 10.46 GHz.

Experimental Study on Strength Characteristics of Chopped Glass Fiber (CGF) Cement-Mortar Composites

K. Ramakrishnan; C. Vijayvenkatesh

Advanced Materials Letters, 2020, Volume 11, Issue 7, Pages 1-6
DOI: 10.5185/amlett.2020.071541

Chopped Glass Fiber (CGF) manufactured by a specification of materials in glass fiber diameter 9 to 25 micron its formed silica-based formulations of glass. Is flexible, lightweight and durability without oxidation, CGF adds enough material quantity to resist the anticipated tensile loads. The hardened CGF composite mortars are inflated ductility resistant and absorbed upper load energy. CGF fiber compound mix materials consist of top strength, glass fiber implant in a cementitious matrix. CGF is another admixtures and alkali resistance. In this research evaluating the different percentages CGF mix with the cement mortar and test in different casted specimens. Appraised the specimens is increased ductility individuality, through the direct compression, tensile, elastic modules strength test. CGF mix cement mortar its high improvements of a (tensile) strength of the better composites. CGF fiber mix is a high mechanical properties consequence outcome. Con-currently fiber cement mortar composites are more efficiency of tensile and compression strength.