Exploring adsorption mechanism of hydrogen cyanide and cyanogen chloride molecules on arsenene nanoribbon from first-principles

A qualitative study on barriers and strategies to hospital preparedness against chemical, biological, radiological, and nuclear incidents

BACKGROUND

The effects of chemical, biological, radiological, and nuclear (CBRN) incidents on human society can be irreparable. Preparing the health system for these incidents is essential. This study aims to identify obstacles to hospital preparedness against CBRN incidents and provide solutions.

MATERIALS AND METHODS

This qualitative study was conducted using semi-structured interview method in 2022. The research community included experts in the fields of CBRN, and 17 persons were included in the study through purposive sampling. The interviews were collected by interview guide and recorded face-to-face and online and were analyzed using thematic content analysis method in MS Word 2016.

RESULTS

The interviews' analysis was classified into two main categories and 34 sub-categories. Some of the most important obstacles to the hospital preparedness against CBRN incidents were the lack of proper crisis management, the lack of specialist staff, the stress of employees, the lack of turnover and sufficient rest for employees, legal gaps, and so on. The main strategies were determining the type and extent of the risk factor, strong crisis management, the lack of parallelism, continuous monitoring, having a protocol and road map, appropriate training programs, having skilled personnel, rapid response of personnel, positive attitude of the staff, and the favorable condition of the building.

CONCLUSION

The appointment of an expert in the field of CBRN and having a specialized unit, the existence of specialized and trained staff along with access to the required facilities, clear instructions, and intra-departmental and inter-departmental cooperation affect the readiness of hospitals against CBRN incidents.

Mechanical characteristics and failure behavior of puckered and buckled allotropes of antimonene nanotubes: a molecular dynamics study

In recent years, antimonene nanotubes have attracted considerable interest for diverse applications owing to their promising physical properties. In this study, classical molecular dynamics simulations with Stillinger-Weber potential were carried out to explore the fundamental mechanical characteristics of two stable allotropes of antimonene nanotubes (SbNTs), namely puckered (α-) and buckled (β-) nanotubes. Mechanical properties and deformation mechanisms of antimonene nanotubes, including ultimate tensile strength, fracture strain, and Young's modulus, were thoroughly examined by considering chirality, diameter, temperature, and strain rate variables. Numerical simulations revealed that all SbNT specimens examined in this study exhibit brittle failures with a complete loss of load-bearing capability following the ultimate stress level. The brittle nature of the SbNTs with varied diameters remained unchanged under different temperatures and loading-rate conditions. Owing to their distinct crystal structure in the armchair and zigzag directions, α-SbNTs present a distinctive anisotropic behavior compared to β-SbNTs. While the variation of the elastic modulus with temperature is not notable, the tensile strength and fracture strain of SbNTs deteriorated considerably at high temperatures. Furthermore, it was observed that the effects of diameter and temperature on zigzag α-SbNT are more pronounced due to its lower stability. Altogether, this study presents a comprehensive examination of the mechanical characteristics of the two stable antimonene allotropes and provides useful information for their potential utilizations in a wide range of applications.

Cyclic versus straight chain oligofuran as sensor: A detailed DFT study

This study presents a novel approach for exploring the sensitivity and selectivity of cyclic oligofuran (5/6/7CF) toward gaseous analytes and their comparison with straight chain analogues (5/6/7SF). The work is not only vital to understand the superior sensitivity but also for rational design of new sensors based on cyclic ring structures of oligofuran. Interaction of cyclic and straight chain oligofuran with NH₃, CO, CO₂, N₂H₄, HCN, H₂O₂, H₂S, CH₄, CH₃OH, SO₂, SO₃ and H₂O analytes is studied via DFT calculation at B3LYP-D3/6-31++G (d, p) level of theory. The sensitivity and selectivity are illustrated by the thermodynamic parameters (E_bind, SAPT0 energies, NCI analysis), electronic properties (H-L gap, percentage of average energy gap, CHELPG charge transfer, DOS spectra), and UV-Vis analysis. All these properties are simulated at B3LYP/6-31G (d) level of theory while UV-Vis is calculated at TD-DFT method. Cyclic oligofurans have high binding energies with analytes compared to 5/6/7SF which corresponds to higher sensitivity of 5/6/7CF. Furthermore, the cyclization of oligofuran significantly improves the sensitivity and selectivity of the system. Alteration in electronic properties of 5/6/7CF and 5/6/7SF is remarkably high upon complexation with SO₂ and SO₃. Further the stability of rings (5, 6 and 7 membered cyclic oligofurans) and their SO₃ complexes is also confirmed by molecular dynamics calculations. The findings of the work clearly suggest that the cyclic geometry enhances not only sensitivity but also selectivity of conducting polymers (oligofuran).

Exploring adsorption behavior of ethylene dichloride and dibromide vapors on blue phosphorene nanosheets: A first-principles acumens

The interrelation of toxic vapors ethylene dichloride (EDC) and ethylene dibromide (EDB) with the sensory base material blue phosphorene nanosheet (BLPNS) is studied using ab-initio method. The formational stability of BLPNS is ensured by the negative value of formation energy. Prior to the adsorption studies, we calculated the formation energy of BLPNS to ensure its stability, which is calculated to be -5.194eV/atom and found stable. The main motive behind the present work is to detect these toxic vapors using BLPNS. The intercommunication between the targeted vapors and the base material has been analyzed using the aid of adsorption energy, Bader charge transfer, energy band gap, and variation of band gap along with energy bands and DOS spectrum. The energy gap of isolated BLPNS is observed to be 1.621eV. However, the adsorption of EDC and EDB modulates the energy gap of BLPNS. The nature of assimilation is noticed to be of physisorption, which facilitates desorption of EDC and EDB molecules much easier. The successful outcome of the present research validates that BLPNS can be deployed as a prominent sensor for detection of EDC and EDB effectively.

Theoretical prediction of 2D XI2 (X=Si, Ge, Sn, Pb) monolayers by density functional theory

Two dimensional monolayer semiconductors play an important role in designing opto-electronic devices for applications. In this paper, through the properties of the density functional theory, by running a series of first principles computations, the stability and the electronic properties of XI₂ (X = Si, Ge, Sn, Pb) monolayer structures is investigated. Our calculations indicate that 2D SiI₂, GeI₂, SnI₂, and PbI₂ monolayer materials show good stabilities. Accessing on their electronic properties indicates that they have semiconducting nature with strain tunable indirect band gaps of 2.38, 2.80, 2.72, and 3.23 eV respectively which are obtained by functional (HSE06) level of theory. The obtained electronic properties can be effectively tuned by strain effects suggests the predicted 2D monolayer materials for application in new opto-electronic devices.