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A numerical investigation has been conducted to study the convective heat transfer enhancement and friction loss behaviors for turbulent flow by using arrays of differently shaped ribs combined with delta-winglet vortex generators (DWVGs) pair on the absorber plate of a solar air heater. Four transverse vortex generators arrays, i.e., 90° continuous ribs, 90° truncated ribs, 60° V-shaped continuou
The difficult manufacturing of helical baffles hinders the widespread application of the enhancement technology and the shortcut leakage between adjacent baffles impairs the enhancement effects. To solve these two issues, the promising anti-leakage and easy-to-manufacture helical baffles with small inclined angle and folded structure are proposed, which can be produced by 2D laser cutting and simp
In this paper, effects of four different hole configurations on film cooling performance and particle deposition are investigated numerically on a curved surface. The RNG k-ε turbulence model is used, and the discrete phase model is developed by user-defined functions. The particle deposition on the curved surface is analyzed by calculated results of capture and impact efficiencies. Results show t
Objectives There is evidence that emergency department (ED) crowding is associated with increased mortality, however large multicenter studies of high quality are scarce. In a prior study, we introduced a proxy-measure for crowding that was associated with increased mortality. The national registry SVAR enables us to study the association in a more heterogenous group of EDs with more recent data.
In this study, the effect of axial heat conduction on thermal performance in a zigzag channel printed circuit heat exchanger (PCHE) with supercritical liquefied natural gas as the working fluid is studied by a numerical method under different conditions. The influence factors include Reynolds number, operating pressure, inlet temperatures of the cold side, and wall thermal conductivity. The result
Background: Esophageal atresia (EA) affects around 2.3–2.6 per 10,000 births world-wide. Infants born with this condition require surgical correction soon after birth. Most survival studies of infants with EA are locally or regionally based. We aimed to describe survival across multiple world regions. Methods: We included infants diagnosed with EA between 1980 and 2015 from 24 birth defects survei
Ferroelectric memories based on hafnium oxide are an attractive alternative to conventional memory technologies due to their scalability and energy efficiency. However, there are still many open questions regarding the optimal material stack and processing conditions for reliable device performance. Here, we report on the impact of the sputtering process conditions of the commonly used TiN top ele
A steam methane reforming reactor is a key equipment in hydrogen production, and numerical analysis and process control can provide a critical insight into its reforming mechanisms and flexible operation in real engineering applications. The present paper firstly studies the transport phenomena in an industrial-scale steam methane reforming reactor by transient numerical simulations. Wall effect a
Catalysts are materials that accelerate the rate of a desired chemical reaction. As such, they constitute an integral part in many applications ranging from the production of fine chemicals in chemical industry to exhaust gas treatment in vehicles. Accordingly, it is of utmost economic interest to improve catalyst efficiency and performance, which requires an understanding of the interplay between
Background and purpose — Reported revision rates due to dislocation after hemiarthroplasty span a wide range. Dislocations treated with closed reduction are rarely reported despite the fact that they can be expected to constitute most of the dislocations that occur. We aimed to describe the total dislocation rate on the national level, and to identify risk factors for dislocation. Patients and met
Researchers have measured superfluid helium’s full dispersion spectrum, explaining discrepancies in previous studies and constraining theories of superfluidity.
γ-CoV2O6 is a quasi-one-dimensional spin-3/2 magnet that possesses two distinct magnetic orders at low temperatures with propagation vectors k1=(½,0,0) and k2=(¼ + δh, δk, - ¼ + δl), respectively. Here we use muon spin relaxation and rotation to reveal the thermodynamics of the magnetic phase separation in this compound. In the paramagnetic (PM) region, short-range correlated spin clusters emerge
By measuring a linear response function directly, such as the dynamic susceptibility, one can understand fundamental material properties. However, a fresh perspective can be offered by studying fluctuations. This can be related back to the dynamic susceptibility through the fluctuation–dissipation theorem, which relates the fluctuations in a system to its response, an alternate route to access the
Health complaints are increasing among adolescents and are recognized as a global public health issue. Health complaints are an indicator for subjective ill-being, but little is known about the relationship between sadness and other health complaints. The aim of this study was to investigate sadness and other health complaints among Swedish adolescents. A survey with a cross-sectional design was c
A numerical method is utilized in this paper to study the effects of varying divider inclination angle on the flow structure and heat transfer characteristics in a ribbed two-pass channel for Reynolds number varying from 10,000 to 50,000. The studied divider inclination angles are −3°,−2°,−1°,0°, +1°, +2° and +3°. The ribs have an orientating angle of 45°. The results show that the heat transfer i
Dual-energy X-ray absorptiometry (DXA)-derived appendicular lean mass/height2 (ALM/ht2) is the most commonly used estimate of muscle mass in the assessment of sarcopenia, but its predictive value for fracture is substantially attenuated by femoral neck (fn) bone mineral density (BMD). We investigated predictive value of 11 sarcopenia definitions for incident fracture, independent of fnBMD, fractur
Background: The hand is the second most fractured region in children. It is therefore important to update fracture epidemiology to be able to identify time trends for adequate health care planning. This study reports pediatric hand fracture incidence 2014–2016 and, using published data, also long-term time trends in 1950–2016. Patients and methods: The Swedish city of Malmö, with 328,494 inhabitan
This thesis is devoted to the understanding, application, and extension of coherent lensless imaging methods for microscopy purposes. Particular attention is given to the Fourier transform holography and coherent diffractive imaging methods.These two methods share several properties such as the ability for singleshot imaging and their experimental geometries, but differ greatly in their reconstruc
This article is a philosophical review of school nursing and its constructs framed by Barbara Dossey’s holistic nursing theory. The author describes the application of holistic nursing theory within the school nurse’s area of activity. The review suggests that holistic nursing theory can be applied in several areas of school nursing. School nurses have a multifaceted occupation that includes meeti
In this paper, the enhanced heat transfer performance and mechanism of a multi-tube heat exchanger (MTHX) with outward helically corrugated tubes (HCTs) are investigated by a numerical approach. Three types of tube arrangement (circle, square and triangle, indicated as CTA, STA and TSA, respectively) and four different tube spacings (1.25, 1.375, 1.5 and 1.625) are compared for Reynolds (Re) numbe
