by Angelo Morro

Received: 19 February 2021;  Published: 13 April 2021;  doi: 10.21926/rpm.2102011

The objective of the paper is twofold: first, to review the classical diffusion models and show the approximations at the origin of the parabolic character of the classical equations; second, to demonstrate a connection between the quantum and classical models of diffusion. As diffusion is inherently related to the motion of constituents, the consistent models are framed within the dynamics of mixtures. The derivation of diffusion equations is then determined based on the related, pertinent approximations.

by Dimitris Kouzoudis  , Georgios Samourgkanidis  and Christos I. Tapeinos

Received: 12 December 2020;  Published: 06 April 2021;  doi: 10.21926/rpm.2102010

In the current work, to identify the bending mode harmonics, 30 microns thin magnetoelastic ribbons made of metallic glass are embedded inside 6 mm thick PLA plastic cantilever beams made by 3-D printing. This is possible because the ribbons are of magnetoelastic nature and thus change their mechanical state inducing a corresponding change in their magnetic state. The ribbons are placed at four different depths, starting with zero depth at the beam’s external surface all the way inside to the beam’s mid-plane. This [...]

by Chandra Mouli Vemury  , Marco Corradi  , Feras Abozaid  , Alasdair Charles  and David Hughes

Received: 19 August 2019;  Published: 30 March 2021;  doi: 10.21926/rpm.2101009

Shape memory alloys (SMA) belong to a family of smart materials, which undergo diffusionless phase transformations when subjected to thermo-mechanical changes making them ideally suitable for utilization in several structural engineering applications. Within this class of materials, Ni-Ti (Nickel-Titanium) alloys are predominantly used due to their non-linear behaviour. Nitinol, one of the Ni-Ti alloys, possesses unique properties such as super-elasticity and shape- memory effect, which makes it suitable for dampin [...]

by Kohl Jacobson  , Sam Strassler  , Courtney Spalt  , Sara Henry  , Arthur Powers  and Donald W. Radford

Received: 22 December 2020;  Published: 29 March 2021;  doi: 10.21926/rpm.2101008

Continuous fiber reinforced geopolymer matrix composites offer the potential for use in structural applications at temperatures up to 700°C, while enabling the manufacture at temperatures below 100°C. Studies have investigated a variety of high temperature structural fiber reinforcements, including carbon, SiC and Al2O3. While there has been active research into various grades of Al2O3 fibers, SiC is most commonly used for high temperature reinforcement of geopolymers in oxidizing environments. Both familie [...]

by Supriya Rattan  , Derek Fawcett  , M. Tennant  , Joanna Granich  and Gerrard Eddy Jai Poinern

Received: 02 November 2020;  Published: 05 March 2021;  doi: 10.21926/rpm.2101007

To date, many studies have examined the development and use of novel materials, enhancing the performance of existing dental composites and improving methods for restoring tooth structure. In recent years, nanotechnology-based techniques have been used to develop a variety of nanomaterial-based dental products aimed at conservative dentistry applications. These new nanomaterial-based materials offer improved physicochemical and mechanical properties, combined with enhanced aesthetics that makes them superior restor [...]

by Paola Stabile  , Francesco Radica  , Luigi Ranza  , Michael R. Carroll  , Carlo Santulli  and Eleonora Paris

Received: 12 December 2020;  Published: 02 March 2021;  doi: 10.21926/rpm.2101006

In this work, two types of wastes were introduced, namely, glass from municipal waste and Construction and Demolition Waste (CDW). The latter, which was obtained from rubble generated by the seismic events occurred in Central Italy in 2016, was introduced in two configurations, the single-layer and the double-layer of the cement-based Terrazzo tiles. A maximum of 77% of waste introduction was proven to be possible, therefore creating the possibility of obtaining construction products including high quantities of se [...]

by Gérald Lopez

Received: 25 November 2020;  Published: 25 February 2021;  doi: 10.21926/rpm.2101005

Polymers such as polyimides and fluoropolymers are widely used for insulating aeronautic wires. They are exposed to various changing factors such as temperature, pressure, moisture, vibration, chafing, etc. The electrification on the horizon can potentially increase the demand for these systems. Indeed, this impending evolution of technology pushes the boundaries of commonly-employed wires. Downsizing systems and enhancing the performance is an urgent requirement. A new generation of insulating materials capable of [...]

by Seong Soo Choi  , Byung Seong Bae  , Kyoung Jin Kim  , Myoung JIn Park  , Yong Min Lee  , Hyun Tae Kim  and Soo Bong Choi

Received: 22 December 2020;  Published: 05 February 2021;  doi: 10.21926/rpm.2101004

We fabricated various nanoaperture plasmonic platforms for single-molecule detection. We fabricated nanoapertures like nanopores on a pyramid and nanoslits on an Au flat membrane using a Ga ion focused ion beam drilling technique, followed by irradiating with a high energy electron beam, dependent on the electron beam current density to obtain nanoapertures with a few nanometer sizes (circular nanopore, nanoslit pores). We examined their optical characteristics with varying aperture sizes and sample thicknesses. We [...]

by Ahalapitiya H Jayatissa  , Omer Ahmed  , Bodhi R Manu  and Adam M Schroeder

Received: 13 August 2020;  Published: 22 January 2021;  doi: 10.21926/rpm.2101003

The tribological properties of ZnO thin film coated on an aluminium work piece by RF magnetron sputtering were studied as a function of deposition power, substrate coating temperature, heat treatment and rotation speed. The variation in the coefficient of friction of ZnO films produced under various levels of coating parameters and conditions were experimentally determined using a pin-on-disk tribometer. The results showed that with change in deposition conditions and heat treatment, there are significant microstru [...]

by Mohammed Faruqi  , Zachary Scott Dean  , Francisco Aguiniga  and Breanna Bailey

Received: 15 November 2020;  Published: 15 January 2021;  doi: 10.21926/rpm.2101002

Prestressed concrete members have gained popularity as an efficient and effective way of designing a structural member with the best engineering and material properties. The method of prestressing a structural concrete member has the capability of controlling increased service loads with less depth over longer spans. However, deflections from over-loading or loading over time give a disadvantage to the common steel reinforced concrete members by the effect of corrosion as the structural concrete develop cracks. To [...]