UV albedo of arctic snow in spring

International audienceThe relevance of snow for climate studies is based on its physical properties, such as high surface reflectivity. Surface ultraviolet (UV) albedo is an essential parameter for various applications based on radiative transfer modeling. Here, new continuous measurements of the local UV albedo of natural Arctic snow were made at Sodankylä (67.37° N, 26.63° E, 179 m a.s.l.) during the spring of 2007. The data were logged at 1-min intervals. The accumulation of snow was up to 68 cm. The surface layer thickness varied from 0.5 to 35 cm with the snow grain size between 0.2 and 2.5 mm. The midday erythemally weighted UV albedo ranged from 0.6 to 0.8 in the accumulation period and 0.5?0.7 during melting. During the snow melt period, under cases of an almost clear sky and variable cloudiness, an unexpected diurnal decrease of 0.05 in albedo soon after midday, and recovery thereafter, was detected. This diurnal decrease in albedo was found to be asymmetric with respect to solar midday, thus indicating a change in the properties of the snow. Independent UV albedo results with two different types of instruments confirm these findings. The measured temperature of the snow surface was below 0°C on the following mornings. Hence, the reversible diurnal change, evident for ~1?2 h, could be explained by the daily metamorphosis of the surface of the snowpack, in which the temperature of the surface increases, melting some of the snow to liquid water, after which the surface freezes again

Diurnal variations in the UV albedo of arctic snow

The relevance of snow for climate studies is based on its physical properties, such as high surface reflectivity. Surface ultraviolet (UV) albedo is an essential parameter for various applications based on radiative transfer modeling. Here, new continuous measurements of the local UV albedo of natural Arctic snow were made at Sodankylä (67°22'N, 26°39'E, 179 m a.s.l.) during the spring of 2007. The data were logged at 1-min intervals. The accumulation of snow was up to 68 cm. The surface layer thickness varied from 0.5 to 35 cm with the snow grain size between 0.2 and 2.5 mm. The midday erythemally weighted UV albedo ranged from 0.6 to 0.8 in the accumulation period, and from 0.5 to 0.7 during melting. During the snow melt period, under cases of an almost clear sky and variable cloudiness, an unexpected diurnal decrease of 0.05 in albedo soon after midday, and recovery thereafter, was detected. This diurnal decrease in albedo was found to be asymmetric with respect to solar midday, thus indicating a change in the properties of the snow. Independent UV albedo results with two different types of instruments confirm these findings. The measured temperature of the snow surface was below 0°C on the following mornings. Hence, the reversible diurnal change, evident for ~1–2 h, could be explained by the daily metamorphosis of the surface of the snowpack, in which the temperature of the surface increases, melting some of the snow to liquid water, after which the surface freezes again

Investigation of liquid-liquid equilibrium in splitting systems containing biofuel component

In this work we obtained data on the liquid-liquid equilibrium in ternary and quaternary splitting systems containing biofuel component – n-butanol. Namely, in systems acetic acid – n-butanol – water, acetic acid – n-butyl acetate – water and acetic acid – n-butanol – n-butyl acetate – water at 45°С and atmospheric pressure. The experimental study was carried out by Gas chromatography method analysis

Ravitsemuskuntoutuksen toteutuminen Kelan järjestämillä kuntoutuskursseilla

Ravitsemuskuntoutuksella (ravitsemusneuvonta ja ruokatarjonta) on erityisen tärkeä merkitys ravitsemukseen liittyvien sairauksien hoidossa ja ehkäisyssä. Sillä voidaan vaikuttaa myönteisesti myös kuntoutujien toiminta- ja työkykyyn sekä elämänlaatuun. Tutkimuksen tarkoitus oli selvittää, miten ravitsemuskuntoutus toteutetaan eri kuntoutuslaitoksissa. Tutkimuksen erityiskohteiksi valittiin seitsemän erityyppistä kuntoutuskurssia. Tiedot kerättiin sähköisellä kyselylomakkeella. Se lähettiin 55 kuntoutuslaitokseen, joissa toteutetaan Kelan järjestämiä kuntoutuskursseja. Vastaukset saatiin 50 (91 %) laitoksesta. Ravitsemusneuvontaa annettiin 45 laitoksessa. Neuvontaa antoi yleisimmin laillistettu ravitsemusterapeutti (80 %), mutta myös muiden ammattiryhmien edustajat, kuten terveyden- ja sairaanhoitajat sekä lääkärit. Neuvonnan tärkeimmiksi aihepiireiksi vastaajat arvioivat seuraavat: terveellinen ravitsemus yleensä, painonhallinta, säännöllinen ateriarytmi, kuidun riittävä saanti sekä rasvojen laatu ja määrä. Ateriatarjonta vastasi hyvin tai melko hyvin annettua ravitsemusneuvontaa lähes kaikissa laitoksissa. Terveellisen aterian koostaminen havainnollistettiin lautasmallin avulla joka neljännessä laitoksessa. Ravitsemuskuntoutuksen kehittämisehdotuksissa painotettiin ravitsemusneuvonnan ja ruokatarjonnan laadun varmistamista sekä joustavuuden ja asiakaslähtöisyyden lisäämistä. Tulosten perusteella voidaan esittää seuraavaa: Jokaisessa kuntoutuslaitoksessa tulisi olla laillistettu ravitsemusterapeutti, joka vastaa siitä, että ravitsemusneuvonta ja ruokatarjonta ovat ravitsemussuositusten mukaisia. Ruokatarjontaa tulisi kohentaa erityisesti parantamalla rasvojen laatua ja vähentämällä suolan käyttöä ruokien valmistuksessa. Lautasmalli tulisi olla esillä kaikissa laitoksissa esimerkkinä terveellisestä ateriasta. Ravitsemuskuntoutusta koskevia standardeja tulisi tarkentaa ja ravitsemuskuntoutus tulisi ottaa Kelan auditoinnin piiriin.20,00 euro

Study of phase equilibrium in splitting systems involving ethyl propionate

Experimental data on liquid–liquid equilibrium (LLE) for the quaternary system propionic acid – ethyl alcohol – ethyl propionate – water and ternary sub-systems were obtained at 20 °C and at atmospheric pressure. The LLE investigated by gas chromatographic method analysis.Maria Toikka is grateful to the Russian Science Foundation (grant 17–73–10290) for the support of this study

Novel approach to determination of sorption in pervaporation process: a case study of isopropanol dehydration by polyamidoimideurea membranes

Development of novel membranes with optimal performance, selectivity, and stability is a key research area in membrane technology. In the present work aromatic polyamidoimideurea (PAIU) is synthesized and tested as promising membrane material for separation of water and alcohol mixtures. The PAIU membrane structure, density, and transport properties are studied. Mass transfer of water and isopropanol through the membrane is estimated by sorption and pervaporation tests to determine equilibrium sorption degree, diffusion coefficients, flux through the membrane, and separation factor. Two techniques of sorption study from liquid and from vapor phases are used as novel approach to experimental study of mass transfer. The vapor sorption calorimetry permits to analyze the behavior of the polymer material in sorption process. In pervaporation of water-isopropanol mixture, almost pure water mainly permeates through PAIU membrane. To improve the performance, a double layer membrane containing a thin PAIU layer on the surface of porous poly(phenylene oxide) support is developed. The double layer membrane is extremely effective in dehydration of isopropanol.Russian Science Foundation (RSF): grant 16-13-10164

Procalcitonin Predicts Response to Beta-Lactam Treatment in Hospitalized Children with Community-Acquired Pneumonia

BACKGROUND: Antibiotic treatment of community-acquired pneumonia (CAP) in children remains mostly empirical because clinical and paraclinical findings poorly discriminate the principal causes of CAP. Fast response to beta-lactam treatment can be considered a proxy of pneumococcal aetiology. We aimed to identify the best biological predictor of response to beta-lactam therapy in children hospitalized for CAP. METHODS: A retrospective, single-centre cohort study included all consecutive patients 1 month to 16 years old hospitalized in a teaching hospital in Paris, France, because of CAP empirically treated with a beta-lactam alone from 2003 to 2010. Uni- and multivariate analyses were used to study the ability of routine biological parameters available in the Emergency Department to predict a favourable response to beta-lactam (defined as apyrexia within 48 hours of treatment onset). RESULTS: Among the 125 included patients, 85% (106) showed a favourable response to beta-lactam. In multivariate logistic regression, we found procalcitonin (PCT) the only independent predictor of apyrexia (p = 0.008). The adjusted odds ratio for the decadic logarithm of PCT was 4.3 (95% CI 1.5-12.7). At ≥ 3 ng/mL, PCT had 55.7% sensitivity (45.7-65.3), 78.9% specificity (54.4-93.9), 93.7% positive predictive value (84.5-98.2), 24.2% negative predictive value (14.2-36.7), 2.64 positive likelihood ratio (1.09-6.42) and 0.56 negative likelihood ratio (0.41-0.77). In the 4 children with a PCT level ≥ 3 ng/mL and who showed no response to beta-lactam treatment, secondary pleural effusion had developed in 3, and viral co-infection was documented in 1. CONCLUSIONS: PCT is the best independent biologic predictor of favourable response to beta-lactam therapy in children hospitalized for CAP. Thus, a high PCT level is highly suggestive of pneumococcal aetiology. However, a 3-ng/mL cut-off does not seem compatible with daily medical practice, and additional research is needed to further define the role of PCT in managing CAP in children