Calculation of Electron Swarm Parameters in Tetrafluoromethane

The electron swarm parameters and electron energy distribution function (EEDF) are necessary, especially onunderstanding quantitatively plasma phenomena and ionized gases. The EEDF and electron swarm parameters including the reduce effective ionization coefficient (α-η)/N (α and η are the ionization and attachment coefficient, respectively), electron drift velocity, electron mean energy, characteristic energy, density  normalized longitudinal diffusion coefficient, and density normalized electron mobility in tetrafluoromethane (CF4) which was analyzed and calculated using the two-term approximation of the Boltzmann equation method at room temperature, over a range of the reduced electric field strength (E/N) between 0.1 and 1000 Td(1Td=10-17 V.cm2), where E is the electric field and N is the gas density of the gas. The calculations required cross-sections of the electron beam, thus published momentum transfer, vibration, electronic excitation, ionization, and attachment cross-sections for CF4 were used, the results of the Boltzmann equation in a good agreement with experimental and theoretical values over the entire range of E/N. In all cases, negative differential conductivity regions were found. It is found that the calculated EEDF closes to Maxwellian distribution and decreases sharply at low E/N. The low energy part of EEDF flats and the high-energy tail of EEDF increases with increase E/N. The EEDF found to be non-Maxwellian when the E/N> 10Td, havingenergy variations which reflect electron/molecule energy exchange processes. In addition, limiting field strength (E/N)limit has been calculated from the plots of (α-η)/N, for which the ionization exactlybalances the electron attachment, which is valid for the analysis of insulation characteristics and application to power equipment

The adsorption of chlorofluoromethane on pristine and Ge-doped silicon carbide nanotube: a PBC-DFT, NBO, and QTAIM study

The feasibility of detecting the chlorofluoromethane (CFM) onto the outer surface of pristine silicon carbide nanotube (SiCNT), as well as its germanium doped structures (SiCGeNT), was carefully evaluated. Density functional theory level of study using the PBE0 functional together with a 6-311G(d) basis set has been used. Subsequently, the B3LYP, CAM-B3LYP, ωB97XD, and M06-2X functionals with a 6-311G(d) basis set were also employed to consider the single point energies. Natural bond orbital (NBO) and quantum theory of atoms in molecules (QTAIM) were implemented by using the PBE0/6-311G(d) method. The total density of states (TDOSs), Wiberg bond index (WBI), natural charge, natural electron configuration, donor–acceptor natural bond orbital interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All results denote that by adsorbing of the gas molecule onto the surface of the considered nanostructures, the intermolecular interactions are of the type of strong physical adsorption. It was revealed that the sensitivity of the adsorption will be increased when the gas molecule interacts with decorated nanotubes and decrease the HOMO-LUMO band gap; therefore, the change of electronic properties can be used to design suitable nanosensors to detect CFM gas

An Ultimate Investigation on the Adsorption of Amantadine on Pristine and Decorated Fullerenes C59X (X=Si, Ge, B, Al, Ga, N, P, and As): A DFT, NBO, and QTAIM Study

In this investigation, the feasibility of detecting the amantadine (AMD) molecule onto the outer surface of pristine fullerene (C60), as well as C59X (X=Si, Ge, B, Al, Ga, N, P, and As) decorated structures, was carefully evaluated. For achieving this goal, a density functional theory level of study using the HSEH1PBE functional together with a 6-311G(d) basis set has been used. Subsequently, the B3LYP-D3, wB97XD and M062X functionals with a 6-311G(d) basis set were also employed to consider the single point energies. Natural bond orbital (NBO) and the quantum theory of atoms in molecules (QTAIM) were implemented using the B3LYP-D3/6-311G(d) method and the results were compatible with the electronic properties. In this regard, the total density of states (TDOSs), the Wiberg bond index (WBI), natural charge, natural electron configuration, donor–acceptor NBO interactions, and the second-order perturbation energies are performed to explore the nature of the intermolecular interactions. All of the energy calculations and population analyses denote that by adsorbing of the AMD molecule onto the surface of the considered nanostructures, the intermolecular interactions are of the type of strong physical adsorption. Among the doped fullerenes, Ge-doped structure has very high adsorption energy compared to other elements. Generally, it was revealed that the sensitivity of the adsorption will be increased when the AMD molecule interacts with the decorated fullerenes and decrease the HOMO–LUMO band gap; therefore, the change of electronic properties can be used to design suitable nanocarrier

Thermal Properties and Magnetic Susceptibility of Hellmann Potential in Aharonov–Bohm (AB) Flux and Magnetic Fields at Zero and Finite Temperatures

In this research work, the Hellmann potential is studied in the presence of external magnetic and AB fux felds within the framework of Schrodinger equation using the Nikiforov–Uvarov functional analysis method. The energy equation and wave function of the system are obtained in closed form. The efect of the felds on the energy spectra of the system is examined in detail. It is found that the AB feld performs better than the magnetic feld in its ability to remove degeneracy. Furthermore, the magnetization and magnetic susceptibility of the system were discussed at zero and fnite temperatures. We evaluate the partition function and use it to evaluate other thermodynamic properties of the system such as magnetic susceptibility,�m(B⃗, �AB, �), Helmholtz free energy F (B⃗, �AB, �), entropy S(B⃗, �AB, �), internal energy U (B⃗, �AB, �)and specifc heat Cv(B⃗, �AB, �). A comparative analysisof the magnetic susceptibility of the system at zero and fnite temperatures shows a similarity in the behavior of the system. A straightforward extension of our results to three dimensions shows that the present result is consistent with what is obtained in the literature

Effects of hospital facilities on patient outcomes after cancer surgery: an international, prospective, observational study

Background Early death after cancer surgery is higher in low-income and middle-income countries (LMICs) compared with in high-income countries, yet the impact of facility characteristics on early postoperative outcomes is unknown. The aim of this study was to examine the association between hospital infrastructure, resource availability, and processes on early outcomes after cancer surgery worldwide.Methods A multimethods analysis was performed as part of the GlobalSurg 3 study-a multicentre, international, prospective cohort study of patients who had surgery for breast, colorectal, or gastric cancer. The primary outcomes were 30-day mortality and 30-day major complication rates. Potentially beneficial hospital facilities were identified by variable selection to select those associated with 30-day mortality. Adjusted outcomes were determined using generalised estimating equations to account for patient characteristics and country-income group, with population stratification by hospital.Findings Between April 1, 2018, and April 23, 2019, facility-level data were collected for 9685 patients across 238 hospitals in 66 countries (91 hospitals in 20 high-income countries; 57 hospitals in 19 upper-middle-income countries; and 90 hospitals in 27 low-income to lower-middle-income countries). The availability of five hospital facilities was inversely associated with mortality: ultrasound, CT scanner, critical care unit, opioid analgesia, and oncologist. After adjustment for case-mix and country income group, hospitals with three or fewer of these facilities (62 hospitals, 1294 patients) had higher mortality compared with those with four or five (adjusted odds ratio [OR] 3.85 [95% CI 2.58-5.75]; p<0.0001), with excess mortality predominantly explained by a limited capacity to rescue following the development of major complications (63.0% vs 82.7%; OR 0.35 [0.23-0.53]; p<0.0001). Across LMICs, improvements in hospital facilities would prevent one to three deaths for every 100 patients undergoing surgery for cancer.Interpretation Hospitals with higher levels of infrastructure and resources have better outcomes after cancer surgery, independent of country income. Without urgent strengthening of hospital infrastructure and resources, the reductions in cancer-associated mortality associated with improved access will not be realised

Associations of Electronic Device Use and Physical Activity with Headaches in Saudi Medical Students

Background and Objectives: Primary headaches are highly prevalent among medical students, negatively impacting their health and academic performance. Excessive electronic device use has been implicated as a risk factor, in contrast to physical activity, which may be a protective factor; however, comprehensive data are lacking, especially for Saudi medical trainees. This study aims to investigate the associations between device use, exercise, and headaches among Saudi medical students. Materials and Methods: In this cross-sectional study, 504 medical students at Jazan University completed an online survey collecting sociodemographic factors, headache characteristics/triggers, electronic device habits, exercise frequency, and headache impacts. Descriptive analyses summarized sample characteristics. Logistic regression identified predictors of 12-month headache prevalence. Results: Overall, 83% reported experiencing headaches in the past year. High headache prevalence was observed among females (86.6%) and third-year students (88.3%). Using electronic devices ≥4 h daily was associated with higher adjusted odds of headaches (OR 13.89, 95% CI 1.96–98.54) compared to ≤1 h daily. Low physical activity (exercising 1 day vs. 7 days a week) also increased headache odds (OR 3.89, 95% CI 1.61–9.42). Headaches impairing productivity (OR 4.39, 95% CI 2.28–8.45) and exacerbated by exercise (OR 10.37, 95% CI 2.02–53.35) were further associated with headache susceptibility. Conclusions: Excessive electronic device use and physical inactivity appear to be modifiable risk factors for frequent headaches in Saudi medical students. Multifaceted interventions incorporating education campaigns, skills training, and support services focused on promoting responsible technology habits, and regular exercise may help mitigate headaches in this population. Robust longitudinal studies and trials are warranted to establish causal mechanisms between lifestyle factors and headaches among medical undergraduates

Workplace Violence Against Doctors in Khartoum State, Sudan, 2020

Background: Workplace violence against healthcare workers and especially doctors are now clearly taken as a rapidly rising health problem in Sudan with great political and legal concerns. The current study was aimed at exploring the prevalence of verbal and physical workplace violence, the major factors associated with it, and its consequences reported by medical staff in Khartoum, Sudan government hospitals in 2020. Methods: This cross-sectional study utilized self-administered questionnaires to collect data on aspects of workplace violence against doctors working in the government hospitals of Khartoum, Sudan. A nine-item self-reported workplace violence scale was used. An online survey of self-reported work-related violence exposure during the preceding 12 months was sent to conveniently selected doctors. In total, 387 doctors completed the questionnaire in 2020. Data were analyzed using the SPSS version 26. Results: One hundred and ninety five (50%) respondents reported they were victims of violence in the previous 12 months; 92% of them experienced nonphysical violence; while female doctors were more likely to experience this type of violence (67%), younger respondents <30 years of age were more likely to encounter violent episodes. Results show an association between exposure to physical violence and working at an emergency department. The assailants were mostly males in the age group of 19–35 years (70.2%), most of them were under no influence (60.8%). Conclusion: Approximately one in every two doctors had experienced some degree of violence, either physical or nonphysical or both, and it was negatively reflected on their psychological status as well as their work performance