by Eugene Adamovich  , Eugenia Buryanskaya  , Anthon Elfimov  , Irina Maklakova  , Oleg Gradov  , Margaret Gradova  and Theodor Orehov

Received: 27 December 2022;  Published: 29 May 2023;  doi: 10.21926/rpm.2302022

In this paper, starting with an introductory review of the applications of liquid crystals and polymer-dispersed liquid crystal systems in (bio)sensors and microfluidics, the possibilities of visualizing self-organization products of liquid crystalline media or field-induced instabilities of liquid crystalline systems are considered. In particular illustrated cases, it is proposed to use FemtoScan software-containing metrological complexes to visualize instabilities in liquid crystalline systems and products of sel [...]

by Subodh K. Mital  , Steven M. Arnold  , Brett A. Bednarcyk  and Evan J. Pineda

Received: 23 January 2023;  Published: 20 June 2023;  doi: 10.21926/rpm.2302025

The behavior and response of ceramic matrix composites (CMCs), in particular silicon carbide fiber reinforced silicon carbide matrix (SiC/SiC), is affected by many factors such as variation of fiber volume fraction, residual stresses resulting from processing of the composites at high temperature, random microstructures, and the presence of matrix flaws (e.g., voids, pores, cracks etc.) as well as general material nonlinearity and heterogeneity that occurs randomly in a composite. Residual stresses arising from the [...]

by Andrew Weems  , Wenyan Li  , Duncan Maitland  and Luz Marina Calle

Received: 12 September 2019;  Published: 31 December 2019;  doi: 10.21926/rpm.1904008

Biomedical applications of shape memory polymers (SMPs) are limited by their biostability, degradability, and possible toxicity risks after implantation. Mesoporous silica nanoparticles (MSNs) were used to increase the oxidative biostability (increase time until degradation occurs) using antioxidants and to induce oxidative degradation through incorporation of hydrogen peroxide-containing MSNs with modified surfaces. The presented results confirm increased oxidative stability using antioxidants, and alternatively, [...]

by Laila Midhat  , Naaila Ouazzani  , Abdessamed Hejjaj  , Ahmed Ouhammou  and Laila Mandi

Received: 29 December 2020;  Published: 22 July 2021;  doi: 10.21926/rpm.2103030

This study aimed to assess the effectiveness of the phytostabilization ability of the native Moroccan plant Citrullus colocynthis on the neutralization of soil acidity and stabilization of metallic trace elements (MTEs) assisted by marble waste. Mine tailings (MT) collected from an abandoned polymetallic site were mixed with powdered marble (PM) using different mixing ratios (%): (MTPM25), (MTPM50), (MTPM75), and agricultural soil (AS) acting as the control. Seeds of C. colocynthis were selected and planted under g [...]

by Omar Alelweet  and Sara Pavia

Received: 09 June 2021;  Published: 13 October 2021;  doi: 10.21926/rpm.2104041

Alkali activated (AA) materials have been investigated for decades as an alternative to Portland cement (PC) products. Most consist of a silicate waste activated with alkalis, which leads to lower green-house gas emissions and a substantial drop in the use of unrenewable material resources. This paper studies the durability of AA materials made with a ground granulated blast furnace slag (GGBS) from Dublin, activated with sodium hydroxide (NaOH), and sodium silicate (Na2SiO3), both combined and separately, and cure [...]

by Francesco Calvani  , Emanuele Bartoletti  , Giancarlo Folchitto  , Stefania Santini  , Michele Fontevecchia  and Alessandra Alhadeff

Received: 06 April 2020;  Published: 11 May 2020;  doi: 10.21926/rpm.2002011

Skin regeneration is a multidisciplinary topic that involves plastic surgery, aesthetics, and dermatology. In the last few years, several molecules have been used to prevent or delay the skin aging process. Recently, promising investigations on novel β-1,3/1,6-glucan-based treatments, associated with sodium hyaluronate, have demonstrated the induction of a naïve biological stimulus in soft tissues. Serum Revitalizing Face (Lot 00118a0051 of 11/19/2018 approved by the Italian Ministry of Health as a Medical Device-C [...]

by Mônica Batista Leite  and Paulo Roberto Lopes Lima

Received: 07 March 2021;  Published: 28 July 2021;  doi: 10.21926/rpm.2103032

The production of concrete using recycled aggregates, obtained from the processing of construction and demolition waste, is extensively practiced worldwide. However, the effect of simultaneous adding fine recycled aggregate and the recycled coarse aggregate on the mechanical properties of concrete is still unfamiliar. This work aims to evaluate the influence of the water/cement ratio (WC Ratio), the fine recycled aggregate content (%FRA), the coarse recycled aggregate content (%CRA), as well as the interaction betw [...]

by Rolf R. Gerhardts

Received: 11 November 2019;  Published: 17 March 2020;  doi: 10.21926/rpm.2001007

We summarize and discuss a self-consistent screening and magneto-transport theory, developed to understand the results of scanning-force-microscope experiments on the current distribution in a two-dimensional electron system (2DES), located in a narrow Hall bar under the conditions of the integer quantum Hall effect (IQHE) and its breakdown. The theory explains why, at low temperatures, at certain intervals of the applied perpendicular magnetic field, the current density is confined to “incompressible stripes” (ISs [...]

by Maria Alonso-González  , José Fernando Rubio-Valle  , Victor Perez-Puyana  , Mercedes Jiménez-Rosado  and Alberto Romero

Received: 01 November 2019;  Published: 26 February 2020;  doi: 10.21926/rpm.2001004

The present study deals with the development of scaffolds based on gelatin (G) and/or chitosan (CH) through modifications in the central processing method. This process consists of the fabrication of a hydrogel which is, then submitted to a freeze-drying stage. To compare the effects of the different modifications, the mechanical properties of the various systems were characterized, employing both dynamic compressive strain and frequency sweep tests. In addition, their porosity as well as the structure and fiber di [...]

by Doo-Sung Lee

Received: 09 December 2020;  Published: 02 June 2021;  doi: 10.21926/rpm.2102021

This paper concerns a poroelastic half-space in which plane compressional waves are scattered by a spherical inclusion. Addition theorems for the spherical wave functions are utilized to meet the boundary conditions on the plane, and the satisfaction of the given conditions on the boundary of the sphere leads to three infinite series equations, whose solution can be acquired by successive approximations. Further, its existence and uniqueness are discussed.

by Otar Tsagareishvili  , Archil Mikeladze  , Roin Chedia  , Tamaz Batsikadze  and Levan Chkhartishvili

Received: 21 March 2024;  Published: 26 August 2024;  doi: 10.21926/rpm.2403021

Tungsten carbide WC-based materials characterized by high hardness and wear resistance have long been widely used in manufacturing cutting and mining tools. They are alloyed or modified with different ceramic phases to improve operational characteristics further. There are obtained the hard tungsten carbide–cobalt WC–Co and tungsten carbide–titanium carbide–cobalt WC–TiC–Co metal-ceramic alloys ultradispersed powders modified with quasieutectic ceramic alloy B4C–30wt.%TiB2 [...]

by Hassan-Ali Hakemi  and Ghazal Hakemi

Received: 05 December 2019;  Published: 03 January 2020;  doi: 10.21926/rpm.2001001

In this study, we explored the phase equilibria in blends of a nematic liquid crystal monomer and a nematic liquid crystal flexible polymer within the whole composition of the phase diagram. The crystal-nematic and nematic-isotropic transition temperatures, as well as the transition enthalpies and entropies, indicated the total miscibility in this mesogenic blend system. We also extracted an empirical axial ratio of 4.52 for the polymer from the nematic-isotropic transitions of the blends. Further, from the biphasi [...]

by Mariarosaria Angrisano  and Francesco Fabbrocino

Received: 02 August 2022;  Published: 11 January 2023;  doi: 10.21926/rpm.2301005

Nowadays, the challenge of climate change and “ecological transition” is substantially an “energy challenge” for every city, which is supposed to become as “energetically self-sufficient” as possible. The construction sector is one of the main contributors to the effects of climate change, starting from the production of materials to the use phase of buildings to their demolition. Recent innovations in sustainable/circular design are related to using “new materials." According to this perspective, nanomaterials are [...]

by Bita Soleimani  , Ali Haghighi Asl  , Behnam Khoshandam  and Khadijeh Hooshyari

Received: 22 June 2024;  Published: 04 November 2024;  doi: 10.21926/rpm.2404025

The escalating global temperatures and their adverse effects underscore the growing imperative for the widespread adoption of clean fuels, notably hydrogen. Proton Exchange Membrane Fuel Cells (PEMFC) emerge as a pivotal green energy technology, facilitating electricity and water generation. The optimization of PEMFC efficiency hinges on the judicious selection and fabrication of polymer membranes. Within innovative materials, Zeolitic Imidazolate Frameworks (ZIFs) represent a novel subclass within the expansive fa [...]

by Alla V. Balueva  , Ilia N. Dashevskiy  and Patricia Todebush

Received: 12 May 2021;  Published: 27 October 2021;  doi: 10.21926/rpm.2104043

One of the ways to improve the fusion of an implant with bone tissue is through the use of biocompatible coatings, in particular, hydroxyapatite (HAp). It is important to assess the strength of the HAp adhesion to the implant. The measure of the strength of the bond of the coating with the substrate is the energy of this bond. Using density functional theory and molecular dynamics, the reaction path, reaction products, oscillation frequency, activation energy and bond energy between different combinations of compon [...]

by Khaled Hassan  , Ian Sims  , Murray Reid  , Alex Smith  and Mohammed Al-Kuwari

Received: 18 April 2021;  Published: 26 September 2021;  doi: 10.21926/rpm.2103038

Wadi gravel is a local aggregate in Qatar that could contribute to enhanced sustainability by replacing expensive imported gabbro. The material needs to be processed before use to reduce sulfate content to acceptable levels. The paper presents the performance assessment of three full-scale buildings, variously made with 50% and 100% Wadi gravel and conventional gabbro concretes. Site monitoring up to four years in service demonstrated the strength development with age and resistance to the aggressive exposure condi [...]

by Georgia Savvidou  , Spyratou Ellas  and Efstathios P Efstathopoulos

Received: 23 April 2024;  Published: 29 August 2024;  doi: 10.21926/rpm.2403022

Nanotechnology is one of the most promising fields of study, and it represents a pioneering leap in science and technology by the precise control over materials at the atomic and molecular level. This transformation affects numerous aspects of modern human life, including medicine, healthcare, electronics, computing, and energy storage. Nanotechnology has shown significant advancements in managing various health problems through different nano-formulations. These engineered nano-systems can be used as drug delivery [...]

by Bhuamik Patel  , Yeswanthi Kamineni  , Shashank Gorityala  and M Hima Bindu

Received: 19 August 2021;  Published: 28 September 2021;  doi: 10.21926/rpm.2103039

Dental caries are one of the major causes of oral degeneration diseases. In order to treat dental-related diseases, it is often challenging and expensive. Recent literature has reported many advances in designing delivery systems utilizing polymers and novel biomaterials. Polymers play an important role in designing many nanoformulations like liposomes, polymeric micelles, polymeric nanoparticles, carbon-based nanoparticles, nano-hydroxyapatite, iron oxide, zirconia, silica, and silver nanoparticles were used to tr [...]

by Yaser Banadaki  , Nariman Razaviarab  , Hadi Fekrmandi  , Guoqiang Li  , Patrick Mensah  , Shuju Bai  and Safura Sharifi

Received: 24 November 2021;  Published: 28 February 2022;  doi: 10.21926/rpm.2201005

Additive Manufacturing (AM) is a crucial component of the smart manufacturing industry. In this paper, we propose an automated quality grading system for the fused deposition modeling (FDM) process as one of the major AM processes using a developed real-time deep convolutional neural network (CNN) model. The CNN model is trained offline using the images of the internal and surface defects in the layer-by-layer deposition of materials and tested online by studying the performance of detecting and grading the failure [...]

by Akash Dakhane  and Narayanan Neithalath

Received: 03 February 2022;  Published: 08 April 2022;  doi: 10.21926/rpm.2202006

The influence of different levels of alkalinity, expressed using M2O-to-binder ratio (n) and activator SiO2-to-M2O ratio (Ms), (M being the Na+ or K+ cation) on the reaction kinetics, compressive strength development and the reaction product formation in slag-based systems activated using alkali powders are discussed. The fundamental idea is to better understand one-part, “just-add-water” type alkali activated binders that are easy-to-use than the systems that rely on liquid activators. The difference in the behavi [...]

by Kamalakanta Sahoo  , Richard Bergman  and Poonam Khatri

Received: 24 August 2021;  Published: 21 December 2021;  doi: 10.21926/rpm.2104049

According to the United Nations Environment Programme (UNEP), the construction and operation of buildings accounted for nearly 38% of total global energy-related CO2 emissions in 2019. The construction sector has been striving to use more low-carbon footprint building products to mitigate climate change and enhance environmentally preferable purchasing. Over the last several decades, there has been substantial growth in engineered wood products for the construction industry. To assess these products used in constru [...]

by Unni Santhosh  and Jalees Ahmad

Received: 06 September 2023;  Published: 01 December 2023;  doi: 10.21926/rpm.2304035

The results of stress analysis of a ceramic matrix composite (CMC) vane using a physics-based model developed for two-dimensional woven CMCs are presented. The model considers the inherent defects and micromechanical damage in woven CMCs along with time-dependent deformation of the constituents. Predictions include damage state under general load conditions and the global deformation response of the vane. Strain-gage data from burst tests are compared to strain predictions obtained using the model. Results from tim [...]

by Navya Uppu  , Kelly McMahen  , Tasneem Khasru  and Mark A. DeCoster

Received: 02 August 2022;  Published: 17 October 2022;  doi: 10.21926/rpm.2204020

Green synthesis of nanomaterials endeavors to reduce the use of high energy methods with those that may include lower temperatures and pressures, use of natural products, and bottom-up self-assembly. Here we describe the generation of metal-organic biohybrids (MOBs) with nanoscale features synthesized at physiological (37°C) and room temperature (25°C). These MOBs utilized the naturally occurring amino acid dimer cystine as the biological component, and a series of metals, including copper, silver, and cobalt. The [...]

by Jeffrey B. Allen  , Guillermo A. Riveros  , Ivan P. Beckman  and Elton L. Freeman

Received: 22 August 2023;  Published: 25 October 2023;  doi: 10.21926/rpm.2304033

In this work, we apply a multiphysics approach to fused deposition modeling to simulate extrusion and solidification. Restricting the work to a single line scan, we focus on the application of polylactic acid. In addition to heat, momentum and mass transfer, the solid/liquid/vapor interface is simulated using a front-tracking, level-set method. The results focus on the evolving temperature, viscosity, and volume fraction and are cast within a set of parametric studies, to include the printing and extrusion speed, a [...]

by Carol Tran  and Laurence J. Walsh

Received: 28 September 2021;  Published: 26 November 2021;  doi: 10.21926/rpm.2104046

Subsurface remineralization can be promoted by the topical application of nanoparticles of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP). To assess changes in enamel white spot lesions, an in situ proof-of-concept investigation was performed using 5 subjects (all of whom were healthy young adults) with a cross-over study design. Custom orthodontic brackets were attached to the buccal surfaces of the maxillary second premolar and first molar teeth. Each bracket had a recess that held a slab of enamel w [...]