Analysis of Milk Powder by Direct Nebulization into Inductively-coupled Plasma

Sample preparation has always been a tedious but important step in analysis involving Inductively Coupled plasma emission spectrometry. In addition, it may also be a source of sample contamination. The present work attempts to overcome these problems by nebulizing milk powder suspensions directly into the plasma. Various infant and full cream milk powders were dispersed in water as well as 0.5% triton-X solution. The suspensions were then analysed for calcium, phosphorus, iron, magnesium and sodium. These elements were successfully determined using inorganic standards with the addition of an internal standard to correct for the difference in viscosities

Hydrogen bonded complexes between nitrogen dioxide, nitric acid, nitrous acid and water with SiH3OH and Si(OH)4

The inter-conversion of nitrogen oxides and oxy acids on silica surfaces is of major atmospheric importance. As a preliminary step towards rationalising experimental observations, and understanding the mechanisms behind such reactions we have looked at the binding energies of NO2, N2O4, HNO3, HONO and H2O with simple proxies of a silica surface, namely SiH3OH and Si(OH)4 units. The geometries of these molecular clusters were optimised at both HF/6-311+G(d) and B3LYP/6-311+G(d) level of theory. The SCF energies of the species were determined at the HF/6-311++G(3df,2pd) and B3LYP/6-311++G(3df,2pd) level. The values indicate that nitric acid is by far the most strongly bound species, in agreement with experimental observations. It was also found that the dimer N2O4 is significantly more strongly bound to the Si(OH)4 and SiH3OH units than NO2 itself. The vibrational frequencies calculated for the hydrogen-bonded complexes are compared to the experimentally observed frequencies of the adsorbed species where possible

Is the Scottish population living dangerously? Prevalence of multiple risk factors: the Scottish Health Survey 2003

<b>Background:</b> Risk factors are often considered individually, we aimed to investigate the prevalence of combinations of multiple behavioural risk factors and their association with socioeconomic determinants.<p></p> <b>Methods:</b> Multinomial logistic regression was used to model the associations between socioeconomic factors and multiple risk factors from data in the Scottish Health Survey 2003. Prevalence of five main behavioural risk factors - smoking alcohol, diet, overweight/obesity, and physical inactivity, and the odds in relation to demographic, individual and area socioeconomic factors.<p></p> <b>Results:</b> Full data were available on 6,574 subjects (80.7% of the survey sample). Nearly the whole adult population (97.5%) reported to have at least one behavioural risk factor; while 55% have three or more risk factors; and nearly 20% have four or all five risk factors. The most important determinants for having four or five multiple risk factors were low educational attainment which conferred around a 3-fold increased odds compared to high education; and residence in the most deprived communities (relative to least deprived) which had greater than 3-fold increased odds.<p></p> <b>Conclusions:</b> The prevalence of multiple behavioural risk factors was high and the prevalence of absence of all risk factors very low. These behavioural patterns were socioeconomically determined. Policy to address factors needs to be joined up and better consider underlying socioeconomic circumstances.<p></p&gt

Computing stationary free-surface shapes in microfluidics

A finite-element algorithm for computing free-surface flows driven by arbitrary body forces is presented. The algorithm is primarily designed for the microfluidic parameter range where (i) the Reynolds number is small and (ii) force-driven pressure and flow fields compete with the surface tension for the shape of a stationary free surface. The free surface shape is represented by the boundaries of finite elements that move according to the stress applied by the adjacent fluid. Additionally, the surface tends to minimize its free energy and by that adapts its curvature to balance the normal stress at the surface. The numerical approach consists of the iteration of two alternating steps: The solution of a fluidic problem in a prescribed domain with slip boundary conditions at the free surface and a consecutive update of the domain driven by the previously determined pressure and velocity fields. ...Comment: Revised versio

Updated world map of the Köppen-Geiger climate classification

International audienceAlthough now over 100 years old, the classification of climate originally formulated by Wladimir Köppen and modified by his collaborators and successors, is still in widespread use. It is widely used in teaching school and undergraduate courses on climate. It is also still in regular use by researchers across a range of disciplines as a basis for climatic regionalisation of variables and for assessing the output of global climate models. Here we have produced a new global map of climate using the Köppen-Geiger system based on a large global data set of long-term monthly precipitation and temperature station time series. Climatic variables used in the Köppen-Geiger system were calculated at each station and interpolated between stations using a two-dimensional (latitude and longitude) thin-plate spline with tension onto a 0.1°×0.1° grid for each continent. We discuss some problems in dealing with sites that are not uniquely classified into one climate type by the Köppen-Geiger system and assess the outcomes on a continent by continent basis. Globally the most common climate type by land area is BWh (14.2%, Hot desert) followed by Aw (11.5%, Tropical savannah). The updated world Köppen-Geiger climate map is freely available electronically in the Supplementary Material Section

Heat Capacity in Magnetic and Electric Fields Near the Ferroelectric Transition in Tri-Glycine Sulfate

Specific-heat measurements are reported near the Curie temperature ($T_C$~= 320 K) on tri-glycine sulfate. Measurements were made on crystals whose surfaces were either non-grounded or short-circuited, and were carried out in magnetic fields up to 9 T and electric fields up to 220 V/cm. In non-grounded crystals we find that the shape of the specific-heat anomaly near $T_C$ is thermally broadened. However, the anomaly changes to the characteristic sharp $\lambda$-shape expected for a continuous transition with the application of either a magnetic field or an electric field. In crystals whose surfaces were short-circuited with gold, the characteristic $\lambda$-shape appeared in the absence of an external field. This effect enabled a determination of the critical exponents above and below $T_C$, and may be understood on the basis that the surface charge originating from the pyroelectric coefficient, $dP/dT$, behaves as if shorted by external magnetic or electric fields.Comment: 4 Pages, 4 Figures. To Appear in Applied Physics Letters_ January 200

Numerical Evolution of axisymmetric vacuum spacetimes: a code based on the Galerkin method

We present the first numerical code based on the Galerkin and Collocation methods to integrate the field equations of the Bondi problem. The Galerkin method like all spectral methods provide high accuracy with moderate computational effort. Several numerical tests were performed to verify the issues of convergence, stability and accuracy with promising results. This code opens up several possibilities of applications in more general scenarios for studying the evolution of spacetimes with gravitational waves.Comment: 11 pages, 6 figures. To appear in Classical and Quantum Gravit

Effects of once-weekly semaglutide on appetite, energy intake, control of eating, food preference and body weight in subjects with obesity.

AIM: To investigate the mechanism of action for body weight loss with semaglutide. MATERIALS AND METHODS: This randomised, double-blind, placebo-controlled, two-period crossover trial investigated the effects of 12 weeks treatment with once-weekly subcutaneous semaglutide, dose-escalated to 1.0 mg, in 30 subjects with obesity. Ad libitum energy intake, ratings of appetite, thirst, nausea and well-being, control of eating, food preference, resting metabolic rate, body weight and body composition were assessed. RESULTS: After a standardised breakfast, semaglutide, compared with placebo, led to a lower ad libitum energy intake during lunch (-1255 kJ; P < 0.0001), and during the subsequent evening meal (P = 0.0401) and snacks (P = 0.0034), resulting in a 24% reduction in total energy intake across all ad libitum meals throughout the day (-3036 kJ; P < 0.0001). Fasting overall appetite suppression scores were improved with semaglutide versus placebo, while nausea ratings were similar. Semaglutide was associated with less hunger and food cravings, better control of eating and a lower preference for high-fat foods. Resting metabolic rate, adjusted for lean body mass, did not differ between treatments. Semaglutide led to a reduction from baseline in mean body weight of 5.0 kg, predominantly from body fat mass. CONCLUSION: After 12 weeks' treatment, ad libitum energy intake was substantially lower with semaglutide versus placebo with a corresponding loss of body weight observed with semaglutide. In addition to reduced energy intake, likely mechanisms for semaglutide-induced weight loss included less appetite and food cravings, better control of eating and lower relative preference for fatty, energy-dense foods