Theoretical study of hydrogen transport during plastic deformation in iron

In order to model hydrogen transport during plastic deformation, it is essential to take into account the combined effect of several interactions: the interaction of hydrogen with newly generated dislocations, the interactions between hydrogen in lattice sites and moving dislocations, and the effect of both of these on the diffusion process. Both atomistic and macroscopic diffusion models, which take into account all of the above interactions, have been developed. The results show that the hydrogen flux due to moving dislocations strongly depends upon the kinetics between hydrogen in moving dislocations and that in lattice. It was also found that the dynamic trapping effect, i.e. trapping associated with an increase in the population of dislocations, should be taken into account to properly model hydrogen transport during plastic deformation.     

Parameters analysis on organic rankine cycle energy recovery system

A systematic algorithm of parameters analysis on an Organic Rankine Cycle (ORC) energy recovery system has been proposed. It includes thermodynamic analysis, economic evaluation and sensitivity analysis, and economical design parameters study. The cases studied indicate that the effects of the design parameters (T_H, T_L, T₁, and E_g) on the system's economic feasibility are very significant, and there is an economical combination of those parameters. Annual operation hours, electricity unit cost, and equipment manufactured cost are also important parameters to the integrated benefit of an ORC recovery system. Moreover, it shows that the recovery of low temperature, gas phase waste heat by an ORC system is economically unattractive; however, the recovery of low-pressure waste steam by an ORC system has been shown to be a high potential for moderate capacity plants.     

Anti-Inflammatory and Antiviral Effects of Cannabinoids in Inhibiting and Preventing SARS-CoV-2 Infection

The COVID-19 pandemic caused by the SARS-CoV-2 virus made it necessary to search for new options for both causal treatment and mitigation of its symptoms. Scientists and researchers around the world are constantly looking for the best therapeutic options. These difficult circumstances have also spurred the re-examination of the potential of natural substances contained in Cannabis sativa L. Cannabinoids, apart from CB1 and CB2 receptors, may act multifacetedly through a number of other receptors, such as the GPR55, TRPV1, PPARs, 5-HT1A, adenosine and glycine receptors. The complex anti-inflammatory and antiviral effects of cannabinoids have been confirmed by interactions with various signaling pathways. Considering the fact that the SARS-CoV-2 virus causes excessive immune response and triggers an inflammatory cascade, and that cannabinoids have the ability to regulate these processes, it can be assumed that they have potential to be used in the treatment of COVID-19. During the pandemic, there were many publications on the subject of COVID-19, which indicate the potential impact of cannabinoids not only on the course of the disease, but also their role in prevention. It is worth noting that the anti-inflammatory and antiviral potential are shown not only by well-known cannabinoids, such as cannabidiol (CBD), but also secondary cannabinoids, such as cannabigerolic acid (CBGA) and terpenes, emphasizing the role of all of the plant’s compounds and the entourage effect. This article presents a narrative review of the current knowledge in this area available in the PubMed, Scopus and Web of Science medical databases.     

Branched copolymers with biodegradable core and pendant oxirane groups

The reactive oxirane groups were incorporated into the macromolecule as substituents in the side chains of loosely‐grafted copolymer or in the arms of star‐shaped copolymer using glycidyl methacrylate (GMA) in the controlled atom transfer radical polymerization (ATRP). The branched GMA copolymers with various architectures were obtained by using hydrophobic copolymers containing six and seven units of caprolactone 2‐(methacryloyloxy)ethyl ester (CLMA) functionalized with bromoester groups, and trifunctional poly(ε‐caprolactone) (PCL), as well as hydrophilic tri‐, and six‐functional acetal derivatives of D ‐glucopyranosides as (macro)initiators with biodegradable and biocompatible properties. The well‐defined copolymers with core‐shell structures and polymerization degrees of GMA in the range of 20–100 per side chain/arm at 20–70% of monomer conversion within 1–6 h and narrow molecular weight distributions (M_w/M_n = 1.14–1.4) were obtained. POLYM. ENG. SCI., 2013. © 2012 Society of Plastics Engineers     

Some case histories of wear-related failures of metallic materials

Several case histories of wear-related failures of metallic parts are presented. In addition to failure analysis, corrective measures are outlined. The materials studied were austenitic manganese steels, tool steels, cast iron and a nickel alloy.Wear-induced failures occurred by mechanisms of abrasion, cavitation and erosion-corrosion. Failures were due to improper choice of material, process embrittlement, the use of inappropriate alloys, faulty heat treatment, poor design, defective materials, lack of environmental control or a combination of some of the above causes.     

Commutator carbon brush effect on the coastdown times of a horizontal motor and a motor-rotor coupled system

An experimental investigation carried out of the coastdown characteristics of a variable-speed d.c. motor and a motor-rotor system is detailed in this paper. The characteristics obtained through an XY recorder in terms of speed vs. time are replotted in terms of deceleration vs. speed for both unreleased and released conditions of the motor commutator carbon brushes during the coastdown experiments. The deceleration vs. speed curves (coastdown curves) for the motor-rotor system resemble the classical Stribeck diagram of friction.     

Experimental and numerical study of diffusion and trapping of hydrogen in plastically deformed A508.Cl.3 steel at room temperature

Hydrogen permeation experiments are performed by the electrochemical method on A508.Cl.3 steel membranes submitted to various stresses. In a first series the stress is kept constant and two successive permeations are conducted; in a second one an increasing stress is applied during the stationary stage of a preliminary permeation. Anomalies of different types (decreasing diffusion coefficient during first permeations in the first series of experiments, abnormal decrease of the exit flux after the dynamic loading in the second series) are encountered and shown to be quantitatively interprétable in terms of irreversible trapping induced by plastic deformations.     

Dynamic time warping in classification and selection of motion capture data

Multidimensional Systems and Signal Processing - The paper is a comprehensive study on classification of motion capture data on the basis of dynamic time warping (DTW) transform. It presents both...