Numerical investigation of heat transfer and fluid flow characteristics of ternary nanofluids through convergent and divergent channels

The characteristics of nanomaterials have garnered significant attention in recent research on natural and forced convection. This study focuses on the forced convection characteristics of ternary nanofluids within convergent and divergent channels. The ternary nanofluid comprises titanium oxide (TiO2), zinc oxide (ZnO), and silver suspended in water, which serves as the base fluid. Using COMSOL Multiphysics 6.0, a reliable software for finite element analysis, numerical simulations were conducted for steady and incompressible two-dimensional flow. Reynolds numbers varying from 100 to 800 were employed to investigate forced convection. Additionally, we explored aspect ratios (channel height divided by the height of the convergent or divergent section) of -0.4, -0.2, 0, 0.2, and 0.4. Our findings revealed that only at aspect ratio a = 0.4 did the average outlet temperature increase as the Reynolds number rose, while other aspect ratios exhibited decreasing average temperatures with declining Reynolds numbers. Moreover, as the Reynolds number increased from 100 to 800 and the total volume fraction of the ternary nanofluids ranged from 0.003 to 0.15, there was a significant 100% enhancement in the average Nusselt number. For clarity, this article briefly presents essential information, such as the study's numerical nature, fluid properties (constant-property fluid), and the methodology (COMSOL Multiphysics 6.0, finite element analysis). Key conclusions are highlighted to enable readers to grasp the main outcomes at a glance. These details are also adequately covered in the manuscript to facilitate a comprehensive understanding of the research. The utilization of this emerging phenomenon holds immense potential in various applications, ranging from the development of highly efficient heat exchangers to the optimization of thermal energy systems. This phenomenon can be harnessed in scenarios in which effective cost management in thermal production is a critical consideration.

Child Anxiety, Depression, and Post-traumatic Stress Disorder Following Orthopedic Trauma

BACKGROUND

Many children and adolescents are exposed to different types of trauma, e.g., abuse or various disasters. Trauma can cause severe and long-term impairment and consequences, the most studied of which are post-traumatic stress disorder (PTSD) and PTSD symptoms (PTSS). PTSD is highly prevalent in clinical practice (with a frequency of about 7%) and is a debilitating consequence of trauma.

AIM

The current study aimed to assess childhood injuries and their associated anxiety, depression, and post-traumatic stress disorder following orthopedic trauma.

METHODS

A descriptive cross-sectional study was conducted, including all pediatric patients with trauma at Abha Maternity and Children Hospital in the Seer region of Saudi Arabia, as well as pediatric patients with trauma at Abha Maternity and Children Hospital during the period from January 1, 2021 to December 31, 2022. Data were collected from the children's caregivers using a direct interview questionnaire to assess the children's personal data, depression, anxiety, and post-traumatic stress disorder. Children's trauma-related data were extracted from their medical records using a pre-structured data extraction sheet.

RESULTS

A total of 100 children with trauma were included. Children ranged in age from eight to 12 years, with a mean age of 7.3 ± 3.4 years. In all, 67 (67.0%) children were males, and only 6 (6.0%) had chronic health problems. The vast majority of the children with trauma had a low-severity experience of depression and anxiety following trauma (97.1% for each), and only one child had a high-severity experience of depression and anxiety. In all, 5 (4.9%) children with trauma experienced clinically significant PTSD, and the vast majority of them showed a low likelihood of the disorder. Multiple fractures and undergoing surgery were significant predictors of developing PTSD (P < 0.05).

CONCLUSION

In conclusion, the current study revealed that bone trauma was frequent among children, mainly due to playing accidents. Also, a low prevalence of post-traumatic stress disorders and their mental consequences was estimated.

Epidemiology and Pattern of Orthopedic Trauma in Children and Adolescents: Implications for Injury Prevention

BACKGROUND

Orthopedic injuries are prevalent in children and can result in hospitalization and damage. The number of accidental injuries among children increases every year, leading to a huge burden on communities and health institutions.

AIM

This study aimed to assess the epidemiological pattern of orthopedic trauma among children and adolescents in Abha, Saudi Arabia.

METHODS

A retrospective record-based study was carried out to investigate the epidemiological pattern of orthopedic trauma among children and adolescents treated at Abha Maternity and Children Hospital in Saudi Arabia, a traumatic center for pediatric patients. The study covered all children and adolescents treated at the hospital for orthopedic trauma. The parents of the children and adolescents were called to get their consent to participate in the study. The following data were extracted from the medical files: personal information, medical history, trauma-related details, management, hospitalization, and complications.

RESULTS

A total of 295 children and adolescents were included. The mean ± standard deviation age was 6.8 ± 3.1 years old (range 1 month to 13 years). Of the patients, 186 (63.1%) were male. The most reported causes of traumas were fall from height (48.1%) and injury while playing (19.7%). The most affected body parts included the forearm (22.4%), head (21.7%), thigh (20%), and leg (10.8%). The vast majority of the children and adolescents (87.1%) had no complications.

CONCLUSION

The current study revealed that pediatric orthopedic injuries are not rare, and there is a higher likelihood of injuries among young male children. Fall from height and play-associated injuries are the most frequent causes.

Non-Fourier energy transmission in power-law hybrid nanofluid flow over a moving sheet

Ethylene glycol is commonly used as a cooling agent in the engine, therefore the study associated with EG has great importance in engineering and mechanical fields. The hybrid nanofluid has been synthesized by adding copper and graphene nanoparticles into the Ethylene glycol, which obeys the power-law rheological model and exhibits shear rate-dependent viscosity. As a result of these features, the power-law model is utilized in conjunction with thermophysical characteristics and basic rules of heat transport in the fluid to simulate the physical situations under consideration. The Darcy Forchhemier hybrid nanofluid flow has been studied under the influence of heat source and magnetic field over a two-dimensionally stretchable moving permeable surface. The phenomena are characterized as a nonlinear system of PDEs. Using resemblance replacement, the modeled equations are simplified to a nondimensional set of ODEs. The Parametric Continuation Method has been used to simulate the resulting sets of nonlinear differential equations. Figures and tables depict the effects of physical constraints on energy, velocity and concentration profiles. It has been noted that the dispersion of copper and graphene nanoparticulate to the base fluid ethylene glycol significantly improves velocity and heat conduction rate over a stretching surface.

Impact of pangolin bootleg market on the dynamics of COVID-19 model

In this paper we consider ant-eating pangolin as a possible source of the novel corona virus (COVID-19) and propose a new mathematical model describing the dynamics of COVID-19 pandemic. Our new model is based on the hypotheses that the pangolin and human populations are divided into measurable partitions and also incorporates pangolin bootleg market or reservoir. First we study the important mathematical properties like existence, boundedness and positivity of solution of the proposed model. After finding the threshold quantity for the underlying model, the possible stationary states are explored. We exploit linearization as well as Lyapanuv function theory to exhibit local stability analysis of the model in terms of the threshold quantity. We then discuss the global stability analyses of the newly introduced model and found conditions for its stability in terms of the basic reproduction number. It is also shown that for certain values of R 0 , our model exhibits a backward bifurcation. Numerical simulations are performed to verify and support our analytical findings.

Right ventricular thrombus in a case of neonatal lupus: case report

Neonatal thrombosis is considered a rare manifestation with unclear aetiology. We reported a neonatal lupus of a Sjogren’s syndrome mother with recurrent miscarriage secondary to antiphospholipid syndrome; seronegative to anticardiolipin antibodies, lupus anticoagulant and B2GP1. She was serologically positive to antiphosphatidylethanolamine and antiprothrombin antibodies, anti-SSA/Ro and anti-SSB/La. The neonate developed neonatal lupus complicated with right ventricular thrombus assumed to be induced by maternal transmission of antiphosphatidylethanolamine and antiprothrombin antibodies, treated successfully with tissue plasminogen activator and warfarin.