Background Childhood anemia is a global public health issue. In this study, we assessed the potential sociodemographic and dietary factors associated with the prevalence of anemia among children aged ...6–59 months in Nigeria. Methods In this cross-sectional study, we collected dietary information and demographic data on 6,338 children with anemia from the Nigerian Demographic and Health Surveys (2018). The association between the occurrence of anemia and the demographic and dietary factors was determined by conducting Chi-squared tests. Additionally, bivariate and multivariate order logit models were constructed and reported as odds ratios. Results The results of the multivariate analysis showed that the risk of anemia was reduced by 13% and 44% in children aged 13–36 months (OR = 0.87; 95% CI = 0.77–0.98; p = 0.019) and 37–59 months (OR = 0.56; 95% CI = 0.49–0.63; p < 0.001), respectively, compared to the risk of anemia in children aged 6–12 months. Anemia was 28% less likely in children of non-anemic mothers (OR = 0.72; 95% CI = 0.66–0.80; p < 0.001) than children of anemic mothers. Children fed pumpkin, carrot, squash, and sweet potato showed a lower occurrence of anemia by 17% (OR = 0.83; 95% CI = 0.70–0.99; p = 0.036) compared to those who were not fed these vegetables. Chances of anemia increased by 14% in children who were fed white potatoes, white yams, manioc, cassava, and other root-based foods (OR = 1.14; 95% CI = 1.01–1.29; p = 0.036). Conclusion This study highlighted the impact of a plant-based diet on the high prevalence of childhood anemia in Nigeria. Therefore, reformation of dietary habits, the inclusion of nutritional supplements, and food-fortification programs with reductions in maternal anemia are recommended.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
This research examines the natural convection phenomena in a triangular enclosure, assumed as a mechanical chamber. Water-based CNT-nanofluid was used as the fluid. The nature of the flow is ...unsteady, and a sinusoidal heat source is situated at the bottom of the triangle. The inclined two walls of the triangle are assumed as cold temperature. Based on the finite element method, dimensionless nonlinear governing equations were obtained employing the Galerkin weighted residual method. Brownian motion of nanoparticles was considered to determine the thermal conductivity and dynamic viscosity. Rayleigh number (Ra), oscillation period τp, and dimensionless time τ are assumed as primary controlling factors, and nanofluid concentration is considered as constant φ = 0.04. The result indicates that the heat transfer rate displays varied patterns varying the Rayleigh number, and it rises as the oscillation period increases. The fluid temperature and flow fields exhibit periodic behavior due to the sinusoidal heat source. The findings of this work can be utilized to build an effective cooling or heating system for the mechanical chamber, ensuring that temperature distributions are effective and consistent.
•Sinusoidal heat source is used on natural convection in a triangular chamber using. Water-based CNT-nanofluid.•Finite element method based Galerkin weighted residual method is applied.•Brownian motion is used to calculate thermal conductivity and diffusivity.•Rayleigh number, oscillation period and dimensionless time are assumed as primary controlling factors.•Fluctuations of thermophysical properties with time are periodic and more complex than sinusoidal nature of the excitation.
This CFD study represents the improvement of cooling performance of Exhaust Gas Recirculation (EGR) by adding newly designed vortex generators inside the engine space of an automobile. The simulation ...of EGR cooler model was validated comparing with the available data and a reasonable agreement has been observed. A total of twelve different shapes of proposed wing-type vortex generators were numerically investigated to compare the cooling effect of a single VG in the duct. For all the studies, a forward inclination angle of 135° was considered as it is the best inclination angle to get the highest vorticity. Among all, it was found that kite type wing VG provides the best cooling effect. Later, the VGs were arranged in several array configurations with 5 different pitch distances to find the best pitch distance. With the 3mm pitch distance in an array, among twelve different VGs, Gothic type wing VG showed the best performance in terms of cooling performance and 11% cooling improvement rather than a single placed VG was determined. Vorticity and cooling effect were also compared by changing the inlet velocity of the exhaust gas. A comparative study was carried out to highlight that Gothic type wing VG performed best in lowering the outlet temperature. Gothic type VG is 12% and 4% more effective than the discrete ribbed and perforated louvered strip VGs respectively.
Efficient healthcare delivery and access to specialized care rely heavily on a well-established healthcare sector referral system. However, the referral system faces significant challenges in ...developing nations like Bangladesh. This study aimed to assess self-referral prevalence among patients attending tertiary care hospitals in Bangladesh and identify the associated factors.
This cross-sectional study was conducted at two tertiary care hospital, involving 822 patients visiting their outpatient or inpatient departments. A semi-structured questionnaire was used for data collection. The patients' mode of referral (self-referral or institutional referral) was considered the outcome variable.
Approximately 58% of the participants were unaware of the referral system. Of all, 59% (485 out of 822) of patients visiting tertiary care hospitals were self-referred, while 41% were referred by other healthcare facilities. The primary reasons for self-referral were inadequate treatment (28%), inadequate facilities (23%), critical cases (14%), and lack of expert physicians (8%). In contrast, institutional referrals were mainly attributed to inadequate facilities to treat the patient (53%), inadequate treatment (47%), difficult-to-treat cases (44%), and lack of expert physicians (31%) at the time of referral. The private facilities received a higher proportion of self-referred patients compared to government hospitals (68% vs. 56%, p < 0.001). Among patients attending the study sites through institutional referral, approximately 10% were referred from community clinics, 6% from union sub-centers, 25% from upazila health complexes, 22% from district hospitals, 22% from other tertiary care hospitals, and 42% from private clinics. Patients visiting the outpatient department (adjusted odds ratio aOR 3.3, 95% confidence interval CI 2.28-4.82, p < 0.001), residing in urban areas (aOR 1.29, 95% CI 1.04-1.64, p = 0.007), belonging to middle- and high-income families (aOR 1.34, 95% CI 1.03-1.62, p = 0.014, and aOR 1.98, 95% CI 1.54-2.46, p = 0.005, respectively), and living within 20 km of healthcare facilities (aOR 3.15, 95% CI 2.24-4.44, p-value < 0.001) exhibited a higher tendency for self-referral to tertiary care facilities.
A considerable number of patients in Bangladesh, particularly those from affluent urban areas and proximity to healthcare facilities, tend to self-refer to tertiary care centers. Inadequacy of facilities in primary care centers significantly influences patients to opt for self-referral.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
•Sinusoidal cavity for variable wavelengths and solid volume fraction using Cu-water nanofluid is developed.•Four different solid volume fractions (ϕ = 0.02, 0.04, 0.06, 0.08), three different ...wavelengths (λ = 2, 3, 4), three different Rayleigh numbers (Ra=103,104, 105) have been considered.•When no magnetic field is applied, the kinetic energy is 1.89 times higher, and the Nusselt number is 7% higher for ϕ = 0.02 than for ϕ = 0.08 for λ = 3.•For no magnetic field intensity, the total entropy generation is 18% higher in ϕ = 0.02 than ϕ = 0.08 for λ = 2.•The highest values of entropy generation are found for the case of Ra=105, while the lowest values are found for the case of Ra=103.
The use of thermofluids in a cavity under magnetohydrodynamics (MHD) with the natural convective flow has been extensively researched, with numerous attempts made by researchers. However, none have examined the role of nanofluid concentrations on a sinusoidal cavity with variable wavelengths at two walls using Cu-water nanofluid with MHD. Therefore, the present study evaluated nanofluid concentration impact in a sinusoidal cavity for three different wavelengths under magnetic field conditions and Rayleigh numbers using Cu-water nanofluid. Four different solid volume fractions (ϕ = 0.02, 0.04, 0.06, 0.08), three different wavelengths (λ = 2, 3, 4), three different Rayleigh numbers (Ra=103,104, 105) have been considered for the study using the finite element method. The LBB-stable element is used to approximate velocities, pressures, and temperatures. The numerical results have been validated from the past study. The variation of kinetic energy, average Nusselt number, viscous, thermal, magnetic, and total entropy generation for various wavelengths has been shown for varying the concentration of nanofluid and Hartmann number. Additionally, the effect of Rayleigh numbers on the entropy generations for three different wavelengths has been presented. The results revealed that the heat transfer rate, kinetic energy, and entropy generation rise with the decreased value of volume concentrations for most of the cases. It is also noticed that these parameters also negatively effect due to the magnetic field. Therefore, with the rise of the Hartmann number, the fluid flow, thermal parameters, and entropy generation decrease. Moreover, Ra has a notable role in entropy generation. Entropy generations have been found higher for Ra=105, and the lowest is found for the case of Ra=103.
•Sinusoidal heat source is used on natural convection in a triangular chamber using. Water-based CNT-nano powder liquid.•Finite element method based Galerkin weighted residual method is ...applied.•Brownian motion is used to calculate thermal conductivity and diffusivity.•Rayleigh number (Ra), solid volume fraction (ϕ) of nano powder, and dimensionless time (τ) are assumed as primary controlling factors for fixed value of oscillation period (τp).•The fluctuations that categorize variations in thermophysical properties with dimensionless time are periodic and more complicated than the sinusoidal nature of the excitation.
Nanoparticle is highly used in enhancing thermal performance, especially in lid-driven cavity flow in powder-related applications. Many researchers considered different conditions, such as MHD, radiation, and mixed convection incorporating nano liquid in such flow. However, no study was carried out with CNT-water nano liquid in a triangular cavity, heated sinusoidally under natural convection to determine the Rayleigh number (Ra) and nano-powder liquid concentration effect on heat transfer. As a result, this study attempts to find the Rayleigh number and particle concentration effects in such transient cavity flow. The governing equations were employed with the Galerkin residual method. While calculating the thermal conductivity and dynamic viscosity of the nano liquid, Brownian motion was taken into consideration. The four solid volume fractions (0.01, 0.05, 0.1, 0.15) and the Ra (104 ≤ Ra ≤ 106) were chosen to evaluate the impact within dimensionless time (0.1 ≤ τ ≤ 1). The findings have been shown by plotting the streamlines, isotherms, heat transfer variation, and pressure gradient. It is found that when the Rayleigh number goes up, the velocity, vorticity, and pressure gradient magnitude become high. But, the fluid flow vortices decrease with dimensionless time. Due to the sinusoidal heat flux conditions, the variation of the result was found to be sinusoidal as well. When the nanoparticle concentration rises, the heat transfer rate and average fluid temperature also increase. Therefore, the highest heat transfer rate is found using the nano liquid with a15% concentration.
Double-diffusive mixed convection problem had been a notable topic of research in the last decade. Lack of study is noticed under mixed convection using this double-diffusive in an enclosure ...specifically for roof-based ventilation systems with unsteady, partially heated conditions. This study investigates the Prandtl number effect in a double-diffusive unsteady flow in a square-shaped room where the upper channel was used for ventilation, and inside the enclosure, the walls are partially heated and mass concentrated. Galerkin residual method was implemented to get the governing equations. The Prandtl number 0.071 ≤ Pr ≤ 7.1 was chosen for the study, changing the dimensionless time 0.1 ≤ τ ≤ 1. The results have been shown in the mode of graphical representation and contour plots to observe the Prandtl number effect in such problem. The velocity streamline, isotherm, isoconcentration plots, heat and mass transfer rate, average fluid temperature and average mass concentration, etc., are shown. Results showed that heat and mass transfer rise with the growth of the Prandtl number. This research would be the guide for the design consideration in such double-diffusive systems like roof-based air ventilation systems with partial heat and mass generation.
•Methods to design new generation of energy absorbing and dissipating helmet liners with PA12 lattice structures.•Generation of high fidelity finite element lattice liner models predicting ductile to ...brittle transition behavior due to strain rate effects.•Linear high energy and oblique impact simulations based on a state-of-the-art helmet standard.•Helmet liners using PA12 lattice structures exhibit improvement in head protection, particularly against the rotational effects.
Existing helmets have a significant but limited ability to reduce the severity of brain injury and the fatality rate during motorcycle accidents. Helmet designs with a special focus on reducing head injuries caused by rotational effects have attracted great interest in recent times. This paper uses a computational approach to study the generation of new helmet designs with lattice liners made of polyamide12 (PA12) material. Three design possibilities and three distinct unit cell topologies were used to create the liners as the energy absorbing and dissipating part of the helmet. PA12 lattice samples were additively manufactured and tested under quasi-static and dynamic compression loads. The test data, showing ductile to brittle transition due to strain-rate effects, were used to validate the finite element models of the lattices. Simulations of the linear high energy and oblique impacts on the coupled headform and liner were carried out following the state-of-the-art helmet standard ECE R22.06. The findings of this study suggest that PA12 lattice liners have an excellent capability of reducing peak rotational acceleration. Many liners can outperform the protection levels offered by existing expandable polystyrene foam liners for single impacts, but at the expense of weight. The performance of the liners can be improved by choosing the topology in such a way that the stress can be distributed through the struts. Moreover, a lattice liner having a balanced energy absorption capability and stiffness would perform better than other lattice liners.
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Vortex generators are passive methods of heat transfer enhancement in any thermal system. However, more research is needed to compare the effects of vortex generators having unique shapes on the flow ...distribution for high heat transmission. Also, a research gap exists in analyzing how different angular orientations of the vortex generator (VG) affect thermohydraulic performance. Therefore, this CFD study aims to propose a total of five novel vortex generator shapes applying modification on a rectangular VG shape, analyzing and comparing the heat transfer and pressure drop properties in a rectangular channel for the Reynolds number varying in the range of Re=4000–11,000. VG-1 (vortex generator-1) with three triangles on its top side, VG-2 with concave shape arc, VG-3 combined with a rectangle and a triangle, VG-4 consists of a rectangle and two triangles at two corners, while VG-5 consists of a rectangle with a triangular inside cut. Among the five designs, VG-1 gives the most optimal hydrothermal performance, incrementing Nusselt number and friction factor of about 38.2 % and 80.38 %, respectively. Combining these two dimensionless parameters, we get the maximum thermal performance factor, TPF, for VG-1, whereas VG-2 performs the least in terms of TPF. Moreover, compared with conventional rectangular VG, VG-1 performed the best with a 1.63 % increase in TPF. Considering the effect of different angular orientations, VG-1 was further studied by applying five vertical inclination angles and four horizontal rotation angle configurations to investigate the impact of inclination and rotational angles. Minimizing the pressure drop penalty, the 30˚ inclination design had the best hydrothermal performance overall, with the highest TPF range of 1.19–1.41, whereas 120˚ variants had the lowest TPF, at 1.09–1.31. Also, for the configuration of the horizontal rotations, 30˚ angle gives the best result, having a slight edge over 150˚case with 1.17–1.41 TPF. Finally, the best cases from vertical inclination and horizontal rotation are combined in a new hybrid configuration, which yielded the maximum TPF of 1.22–1.45, indicating that this configuration is the most effective among all the cases.
Purpose
To evaluate and compare the results of the conjunctival flap (CF) and cryopreserved amniotic membrane graft (AMG) in the management of fungal corneal ulcers either with complications or ...non-responsive to medical treatment.
Study design
A retrospective observational study.
Methods
Medical records of 30 patients with culture-positive fungal corneal ulcer treated with either CF or AMG (15 eyes in each group) in real world settings were retrieved for analysis. After the surgical procedure, patients were followed up on days 1, 7, 14, 21, 30, 60, 90, 120, and 180 to explore the outcomes of the operations along with complications.
Results
Infecting fungi were of genus Fusarium (n = 11), Aspergillus (n = 10), Mucor (n = 4) and Penicillium (n = 10). The most common indication was resistant ulcer with perforation. After the procedure, epithelization was completed in 11(73.33%) patients in the CF, and 13 patients in the (86.67%) AMG group. Visual acuity improvement was significantly better in the latter group (CF: 1 6.67% vs. AMG: 7 46.67%, p = 0.023). Flap failure occurred in 4 patients (26.67%) from the CF and 2 (13.33%) from the AMG group. No significant differences were found between the two groups regarding success rate (p = 0.651), epithelialization time (p = 0.691), healing of corneal ulcer (p = 0.651), and postoperative stability (p = 0.651) of the flaps.
Conclusions
CF and AMG are both effective for the management of refractory fungal corneal ulcers. However, AMG appears to improve visual acuity better than CF.
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