Synthesis and Spark Plasma Sintering of Mg2Si Nanopowder by Mechanical Alloying and Heat Treatment

In this investigation, a two‐step method for the preparation of magnesium silicide (Mg₂Si) nanopowder was studied. This method is known as mechanical alloying followed by heat treatment. The results showed that the compositions of the combustion products depended on the milling time, heat treatment temperature, and starting mixtures. Pure Mg₂Si nanopowder was formed after short milling time and heat treatment, from Mg and Si powders with the mole ratio of 2.1:1 (Mg:Si) at 500°C in Ar atmosphere. Using the Mg₂Si nanopowder, Mg₂Si ceramic was produced by spark plasma sintering at 800°C under 50 MPa for 15 min. Composition and structure of reactants and products were examined by X‐ray diffraction (XRD), field emission scanning electron microscopy (FE‐SEM) and high‐resolution transmission electron microscopy (HR‐TEM).     

Deriving a compiler from an operational semantics written in VDL

This paper addresses the issue of compiler correctness. The approach taken is to systematically construct a correct compiler for a language from a formal semantic definition of the language. For this purpose, an operational semantics of a language is chosen as the basis for the approach. That is, the compiler for a language is derived from an interpreter of the language. The derivation process uses the notion of mixed computation proposed by Ershov. Briefly stated, one begins interpreting and when a primitive state changing instruction is about to be executed, the instruction is emitted as code instead. The correctness of all compilers produced by the method is guaranteed by proving the derivation rules correct. This proof is a one-time task for each specification language. The specification language studied in this paper is the Vienna Definition Language (VDL). The object code generated by the compiler is in an intermediate language close to an assembly language. Therefore, the translation from the intermediate language into the assembly language should be straightforward.     

A full adder structure without cross-wiring in quantum-dot cellular automata with energy dissipation analysis

Quantum-dot cellular automata (QCA) is the appearance of new technology and can be a suitable alternative to semiconductor transistor technology. In this paper, the new structure of the two-input XOR gate is presented, which is the modified version of the three-input XOR gate. This structure can be used to design various useful QCA circuits. By utilizing this gate, we design and implement a new full adder structure with 90-degree cells. This structure is designed in a single layer without cross-wiring. The operation of the proposed structure has been verified by QCADesigner version 2.0.3 and energy dissipation investigated by QCAPro tool. We also compared the effectiveness of our structure with the two previous structures.     

Autophagy,Unfolded Protein Response,and Neuropilin-1 Cross-Talk in SARS-CoV-2 Infection: What Can Be Learned from Other Coronaviruses

The COVID-19 pandemic is caused by the 2019–nCoV/SARS-CoV-2 virus. This severe acute respiratory syndrome is currently a global health emergency and needs much effort to generate an urgent practical treatment to reduce COVID-19 complications and mortality in humans. Viral infection activates various cellular responses in infected cells, including cellular stress responses such as unfolded protein response (UPR) and autophagy, following the inhibition of mTOR. Both UPR and autophagy mechanisms are involved in cellular and tissue homeostasis, apoptosis, innate immunity modulation, and clearance of pathogens such as viral particles. However, during an evolutionary arms race, viruses gain the ability to subvert autophagy and UPR for their benefit. SARS-CoV-2 can enter host cells through binding to cell surface receptors, including angiotensin-converting enzyme 2 (ACE2) and neuropilin-1 (NRP1). ACE2 blockage increases autophagy through mTOR inhibition, leading to gastrointestinal complications during SARS-CoV-2 virus infection. NRP1 is also regulated by the mTOR pathway. An increased NRP1 can enhance the susceptibility of immune system dendritic cells (DCs) to SARS-CoV-2 and induce cytokine storm, which is related to high COVID-19 mortality. Therefore, signaling pathways such as mTOR, UPR, and autophagy may be potential therapeutic targets for COVID-19. Hence, extensive investigations are required to confirm these potentials. Since there is currently no specific treatment for COVID-19 infection, we sought to review and discuss the important roles of autophagy, UPR, and mTOR mechanisms in the regulation of cellular responses to coronavirus infection to help identify new antiviral modalities against SARS-CoV-2 virus.     

A novel approach for supplier selection based on the Kano model and fuzzy MCDM

This paper proposes a three-phase approach for supplier selection based on the Kano model and fuzzy Multi Criteria Decision-Making. Since the supplier selection problem involves different criteria, quality attributes have been assumed to denote the importance weight of the criteria for supplier selection. Furthermore, to consider the inherent vagueness of human thought, a fuzzy logic has been utilised. Initially, the importance weight of the criteria has been calculated using a fuzzy Kano questionnaire and fuzzy analytic hierarchy process. In the second phase, the Fuzzy TOPSIS technique has been used to screen out in capable suppliers. Finally, in the third phase, the filtered suppliers which are qualified, once again will be evaluated by the same approach for the final ranking. The proposed approach has also been examined in a case study.     

Emerging Advances of Nanotechnology in Drug and Vaccine Delivery against Viral Associated Respiratory Infectious Diseases (VARID)

Viral-associated respiratory infectious diseases are one of the most prominent subsets of respiratory failures, known as viral respiratory infections (VRI). VRIs are proceeded by an infection caused by viruses infecting the respiratory system. For the past 100 years, viral associated respiratory epidemics have been the most common cause of infectious disease worldwide. Due to several drawbacks of the current anti-viral treatments, such as drug resistance generation and non-targeting of viral proteins, the development of novel nanotherapeutic or nano-vaccine strategies can be considered essential. Due to their specific physical and biological properties, nanoparticles hold promising opportunities for both anti-viral treatments and vaccines against viral infections. Besides the specific physiological properties of the respiratory system, there is a significant demand for utilizing nano-designs in the production of vaccines or antiviral agents for airway-localized administration. SARS-CoV-2, as an immediate example of respiratory viruses, is an enveloped, positive-sense, single-stranded RNA virus belonging to the coronaviridae family. COVID-19 can lead to acute respiratory distress syndrome, similarly to other members of the coronaviridae. Hence, reviewing the current and past emerging nanotechnology-based medications on similar respiratory viral diseases can identify pathways towards generating novel SARS-CoV-2 nanotherapeutics and/or nano-vaccines.     

Sources and Health Risk of Organic Compounds in Respirable Particles in Tehran,Iran

Forty-one respirable particle (PM₄) samples were collected from October 2011 through March 2012. This timespan covered the fall and winter seasons in Tehran, Iran. The associated polycyclic aromatic hydrocarbon (PAH) and n-alkane concentrations were analyzed to investigate the sources of these compounds and health risks of the former. The average total PAH and n-alkane concentrations were 16.2 ng/m³ and 758 ng/m³, respectively. The most abundant PAHs were 2- and 3-ring compounds, while the most abundant n-alkanes were nC₁₆ and nC₁₈. The results of source identification by factor analysis (FA) are consistent with and complementary to those from diagnostic ratios (DRs). The PAH DRs indicate a dominant contribution from pyrogenic sources, in particular diesel engines from local traffic sources, while FA reveals a diesel-fuelled vehicle emission related factor, a gasoline engine emission-related factor, an industrial source factor and a wood combustion, incineration and tire tread source factor. The n-alkane DRs indicate dominant contributions from anthropogenic sources or vehicular emissions, while FA reveals a fossil fuel combustion factor and a biogenic source factor. Although the average BaP concentration was below the Iran Department of Environment's annual average standard of 1 ng/m³, the BaP-equivalent concentration of the PAHs (BaP_PEQ) indicates harmful effects cannot be ruled out. The ICR_L and ICR_U data suggests a potential cancer risk incidence of about 1–54 individuals per million in the population from a lifetime of 70 years inhalation of particle associated PAHs in Tehran. These findings highlight the importance of reducing emissions from traffic, in particular emissions from diesel-fuelled vehicles, in Tehran.     

Mode II fracture energy characterization of brittle adhesives using compliance calibration method

The end‐notched flexure (ENF) test is widely used for measuring the Mode II critical strain energy release rate of adhesively bonded joints (ABJs). Unstable crack growth in ENF joints with brittle adhesives is a common phenomenon. Classic data reduction methods like the direct beam theory (DBT) and the compliance‐based beam method (CBBM) usually result in unacceptable scatter when crack grows unstable. In this study, the application of a compliance calibration method (CCM) for ENF adhesive joints with a brittle adhesive is experimentally investigated. For this purpose, ENF specimens were manufactured and tested. Different data reduction methods were considered for treating the results. Afterwards, the obtained fracture energies were used as an input parameter in a finite element (FE) analysis with a cohesive zone model to evaluate the validity of the experimental data. It is shown that the fracture loads obtained by the CCM have the best agreement with the experimental ones comparing with the other data reduction approaches. To study the effect of geometry on the CCM results, ENF specimens with different adhesive thicknesses, substrate thicknesses and span lengths were also considered in this study, and some general conclusions are made about the geometrical parameters effect on the Mode II fracture energy.