Prevalence of multiple non-communicable diseases risk factors among adolescents in 140 countries:A population-based study

BACKGROUND: Modifiable non-communicable disease (NCD) risk factors are becoming increasingly common among adolescents, with clustering of these risk factors in individuals of particular concern. The aim of this study was to assess global status of clustering of common modifiable NCD risk factors among adolescents. METHODS: We used latest available data from nationally representative survey for 140 countries, namely the Global School-based Student Health Survey, the Health Behaviour in School-Aged Children and the longitudinal study of Australian Children. Weighted mean estimates of prevalence with corresponding 95% confidence intervals of nine NCD risk factors - physical inactivity, sedentary behaviour, insufficient fruits and vegetable consumption, carbonated soft drink consumption, fast food consumption, tobacco use, alcohol consumption and overweight/obesity - were calculated by country, region and sex. FINDINGS: Over 487,565 adolescents, aged 11–17 years, were included in this study. According to trend analysis, prevalence of four or more NCD risk factors increased gradually over time. Prevalence of four or more NCD risk factors was 14.8% in 2003–2007 and increased to 44% in 2013–2017, an approximately three-fold increase (44.0%). Similar trends were also observed for three and two risk factors. Large variation between countries in the prevalence of adolescents with four or more risk factors was found in all regions. The country level range was higher in the South-East Asia Region (minimum Sri Lanka = 8%, maximum Myanmar = 84%) than Western Pacific Region (minimum China = 3%, maximum Niue = 72%), European Region (minimum Sweden = 13.9%, maximum Ireland = 66.0%), African Region (minimum Senegal = 0.8%, maximum Uganda = 82.1%) and Eastern Mediterranean Region (minimum Libya = 0.2%, maximum Lebanon = 80.2%). Insufficient vegetable consumption, insufficient fruit consumption and physically inactivity were three of the four most prevalent risk factors in all regions. INTERPRETATION: Our results suggest a high prevalence of four or more NCD risk factors in adolescents globally, although variation was found between countries. Results from our study indicate that efforts to reduce adolescent NCD risk factors and the associated health burden need to be improved. These findings can assist policy makers to target the rollout of country- specific interventions. FUNDING: None

Laserstrahlschweißen von Aluminiumlegierungen mit Schwingungsüberlagerung

Eine Schwingungsüberlagerung wurde beim Laserstrahlschweißen von Aluminium verwendet, um die Nahteigenschaften durch ein feinkörnigeres Gefüge zu verbessern und die Heißrissanfälligkeit zu vermindern

Tensile strength of Nitinol flanges fabricated by laser rod end melting and immediate flange processing

Nitinol is a shape memory alloy used for actuator applications. However, the connection between Nitinol wire and mechanical system via adhesive bonding or crimping could be weakened due to the exposure of joint in aggressive environments and temperature changes. Therefore, a process chain called laser rod end melting with immediate flange processing has been put forward and proven to fabricate all-in-one Nitinol flanges. According to previous work, there is a partially solidified preform connecting to the wire as the shaft, where the connection factures under tensile tests. In the present study, the effect of size of partially solidified preform on the tensile behavior was investigated on the cylindrical flanges with different flange heights. The results show that the partial preform volume increases with the flange heights, while the tensile strength becomes smaller when the flange height is too small. This suggests that it is important to maintain the mechanical strength of Nitinol flange by choosing the appropriate flange height.Deutsche Forschungsgemeinschaft DFG, German Research Foundation182

Influence of electrolyte concentration on laser chemical machining

To meet the increasing trend of miniaturization, new (non-conventional) manufacturing processes are constantly being developed. The laser chemical process describes one of these non-conventional removal process in the microscale, based on the thermochemical dissolution of metals. To determine the influence of electrolyte concentrations, linear cavities were created in Titanium Grade 1 using phosphoric acid and sulfuric acid with different concentrations. The experimental results show that as the electrolyte concentration increases, the process window is reduced. One possibility for this is, as the electrolyte concentration increases, the viscosity increases, as well. With increasing viscosity, the electrolyte boiling process, which causes the shielding effect of the gas bubbles becomes more significant. Due to the increasing conductivity of the electrolyte at higher concentrations, the laser chemical removal rate increases within the process window at constant laser power. The maximum removal rate is observed at the maximum conductivity of the electrolyte.Deutsche Forschungsgemeinschaft DFG323

Surface quality of laser rod end melted shape-memory Nitinol preforms

The shape-memory Nitinol as a nickel-titanium alloy is widely used in actuator and medical applications. However, the connection of a flange to the rod is a critical point. Therefore, laser rod end melting enables material accumulations to generate a preform at the end of a rod, followed by die forming, so that the flange can be generated. This process has been successfully applied on 1.4301 steel. This study is aimed to investigate laser rod end melting of shape-memory Nitinol regarding the resultant surface quality of the preforms. The results showed that spherical preforms could be generated without visible surface discoloration due to oxidation. By using different scan rates, different solidification conditions occurred which led to significantly different surface structures. These findings show that laser rod end melting can principally be applied on Nitinol to generate preforms for flanges whereby the surface quality depends on the solidification conditions

Materials Characterization at High Strain Rates

The identification of material properties at high strain rates is of considerable technical interest, e.g., in applications for passenger safety-related parts which are expected to absorb energy in case of collisions. To additionally meet the requirements of a rapid and resource-efficient materials characterization, a novel highspeed hardness testing method based on laser-induced shock waves was investigated. The principal applicability of this laser-induced shockwave indentation technique for materials characterization at high strain rates is shown.Deutsche Forschungsgemeinschaft DFG151

On the combination of plasma nitrided surfaces and LIPSS

LIPSS are subjected to excessive wear when exposed to direct contact in tribological applications. Therefore, precautions must be taken to increase LIPSS’ hardness and wear resistance while simultaneously preserving their properties like superhydrophilicity. This work shows that a firstly plasma nitrided and subsequently structured surface results in LIPSS of high nano-hardness (14.88 GPa ± 1.05 GPa) who show a super hydrophilic wetting behavior (contact angle of 7°). The results indicate that a previous nitriding could bring LIPSS into tribological applications.Deutsche Forschungsgemeinschaft DFG232

Experimental and Numerical Investigation of an Overheated Aluminum Droplet Wetting a Zinc-Coated Steel Surface

Wetting steel surfaces with liquid aluminum without the use of flux can be enabled by the presence of a zinc-coating. The mechanisms behind this effect are not yet fully understood. Research results on single aluminum droplets falling on commercial galvanized steel substrates revealed the good wetting capability of zinc coatings independently from the coating type. The final wetting angle and length are apparently linked to the time where zinc is liquefied during its contact with the overheated aluminum melt. This led to the assumption that the interaction is basically a fluid dynamic effect of liquid aluminum getting locally alloyed by zinc. A numerical model was developed to describe the transient behavior of droplet movement and mixing with the liquefied zinc layer to understand the spreading dynamics. The simulations reveal a displacement of the molten zinc after the impact of the droplet, which ultimately leads to an accumulation of zinc in the outer weld toe after solidification. The simulation approach neglects the effect of evaporating zinc, resulting in a slight overestimation of the final droplet width. However, in terms of spreading initiation during the first milliseconds, the simulation is in good correlation with experimental observations and demonstrates the reason for the good wetting in the presence of zinc coatings

Change of Oxidation Mechanisms by Laser Chemical Machined Rim Zone Modifications of 42CrMo4 Steel

The oxidation mechanism of metals depends, among other factors, on the surface integrity. The surface and rim zone properties are often determined by the manufacturing process that was used to machine the material. Laser chemical machining (LCM) is a manufacturing process that uses laser radiation as a localized and selective heat source to activate a chemical reaction between an electrolyte and a metallic surface. The objective of this work is first to investigate how different LCM processes affect the rim zone properties of 42CrMo4. For this purpose, the surface chemistry is analyzed by EDS and XPS, phases and residual stresses are determined by XRD, and the morphology is investigated by SEM. Second, the influence of these modified rim zones on the oxidation properties of the steel at 500 °C in air is to be demonstrated in oxidation tests by in situ XRD and subsequent SEM/EDS investigations. A decisive influence of the oxides formed on the surface of 42CrMo4 during LCM in different electrolytes (NaNO3 solution and H3PO4) at two different laser powers on the high-temperature oxidation properties was demonstrated. These oxides were supposed to act as nucleation sites for oxide layer formation at 500 °C and led to an overall increase in oxide layer thickness after high-temperature oxidation compared to non-LCM-processed surfaces