Search results for "Concentration."
showing 10 items of 1849 documents
Diurnal variation of tree pollen in the air in finland
1984
Abstract The pollen was collected with Burkard spore traps in Turku and Jyvaskyla, in southern and central Finland. Selected days of high concentration were analysed for hour to hour concentrations. The diurnal variation of pollen concentration was variable in Alnus, Betula, Juniperus and Pinus, while Picea, Populus, Quercus, Salix and Ulmus had regular daytime maxima och nightly minima. The pollen concentrations were closely correlated with increasing temperatures and decreasing relative humidities. A significant relationship with wind speed was also found, except in Alnuts and Betula. The most significant relationships with wind speed were found in Salix and Quercus, the pollen of which t…
Mechanical properties of carbon nanotube fibres: St Venant’s principle at the limit and the role of imperfections
2015
Abstract Carbon nanotube (CNT) fibres, especially if perfect in terms of their purity and alignment, are extremely anisotropic. With their high axial strength but ready slippage between the CNTs, there is utmost difficulty in transferring uniformly any applied force. Finite element analysis is used to predict the stress distribution in CNT fibres loaded by grips attached to their surface, along with the resulting tensile stress–strain curves. This study demonstrates that, in accordance with St Venant’s principle, very considerable length-to-diameter ratios (∼103) are required before the stress becomes uniform across the fibre, even at low strains. It is proposed that lack of perfect orienta…
Intrinsic defects induced by β-irradiation in silica
2002
We report an electron paramagnetic resonance study of defects induced by β-irradiation in natural and synthetic samples of high purity commercial silica. Data are collected for the E′ centers and a resonance satellite signal split by 1.36 mT. By comparison with the effects of γ-irradiation it is shown that the mechanisms of defect generation are the same for the two irradiation sources and that in the high-dose limit they involve intrinsic defects of the glassy matrix. Moreover, the high concentration of defects generated by β-irradiation modifies the EPR spectrum due to spin–spin interaction.
Comparative analysis of major travel and tourism indicators: Estonia, Latvia and Lithuania, 2010
2011
Straipsnio tikslas – lyginant svarbiausius statistinius rodiklius rasti Baltijos šalių turizmo rinkos bendrumus ir ypatumus. Tuo tikslu buvo daroma literatūros šaltinių apžvalga bei analizė, taikoma indukcija bei dedukcija, o taip pat tokie statistiniai metodai, kaip grupavimas, agregavimas bei lyginimas. Tyrimas rodo, kad Estijos kelionių bei turizmo industrijos dalis tiek bendrajame vidaus produkte, tiek ir darbuotojų skaičiumi yra didžiausia ir viršija Europos sąjungos atitinkamų rodiklių vidurkius. Estija tarp Baltijos šalių užima lyderio pozicijas tiek su nakvyne atvykstančių užsienio lankytojų skaičiumi, tiek jų lankytojų šalyje praleistų naktų skaičiumi. Lietuvoje nakvynės paslaugas …
The glass transition in polymer-micronetwork colloids
1995
Dynamic light scattering experiments on a new, wore complex colloidal system reveal that the density fluctuations at high concentration follow a similar pattern as observed for molecular liquids an...
Osmotic conditions in rheologic properties of erytrocites
2001
Abstract The decreasing viability and in vivo survival of red blood cells, RBCs, observed in blood bank-storage are due to alterations in their rheologic properties and metabolic status. However, there is a lack of electrokinetic experiments with erythrocytes by the screening produced by the high concentration of buffer required to keep the isoosmotic conditions. Electrokinetic measurements in a wide range of sodium chloride and tetrasodium pyrophosphate are undertaken on liposomes as cell models, and in order to get an aqueous media suitable for maintaining osmotic conditions and allowing electrophoretic mobility measurements as well, advantage has been taken of dextrose properties. Measur…
Evaluation of activated sludge model no.2 at high phosphorus concentrations
2001
This paper presents laboratory scale experimentation carried out to study enhanced biological phosphorus removal at high phosphorus concentrations in a sequencing batch reactor. Four series of data obtained in a sequencing batch reactor are examined in light of the Activated Sludge Model No. 2. This model was calibrated using data from the first and second series working at low phosphorus concentrations. The Activated Sludge Model No. 2 successfully characterised the enhanced biological phosphorus removal performance of the sequencing batch reactor at low phosphorus concentrations. The calibrated model was then used to adjust experimental results of the other series working at high phosphor…
High rate concentration measurement of molecular gas mixtures using a spatial detection technique
2010
International audience; Concentration measurement in molecular gas mixtures using a snapshot spatial imaging technique is reported. The approach consists of measuring the birefringence of the molecular sample when field-free alignment takes place, each molecular component producing a signal with an amplitude depending on the molecular density. The concentration measurement is obtained on a single-shot basis by probing the time-varying birefringence through femtosecond time-resolved optical polarigraphy (FTOP). The relevance of the method is assessed in air.
Breakdown of high-energy phosphate compounds and lactate accumulation during short supramaximal exercise.
1987
Muscle ATP, creatine phosphate and lactate, and blood pH and lactate were measured in 7 male sprinters before and after running 40, 60, 80 and 100 m at maximal speed. The sprinters were divided into two groups, group 1 being sprinters who achieved a higher maximal speed (10.07 +/- 0.13 m X s-1) than group 2 (9.75 +/- 0.10 m X s-1), and who also maintained the speed for a longer time. The breakdown of high-energy phosphate stores was significantly greater for group 1 than for group 2 for all distances other than 100 m; the breakdown of creatine phosphate for group 1 was almost the same for 40 m as for 100 m. Muscle and blood lactate began to accumulate during the 40 m exercise. The accumulat…
Autophagy, cathepsin L transport, and acidification in cultured rat fibroblasts.
1992
The mechanisms of enzyme delivery to and acidification of early autophagic vacuoles in cultured fibroblasts were elucidated by cryoimmunoelectron microscopic methods. The cation-independent mannose-6-phosphate receptor (MPR) was used as a marker of the pre-lysosomal compartment, and cathepsin L and an acidotropic amine (3-(2,4-dinitroanilino)-3'-amino-N-methyl-dipropylamine (DAMP), a cytochemical probe for low-pH organelles) as markers of both pre-lysosomal and lysosomal compartments. In addition, cationized ferritin was used as an endocytic marker. In ultrastructural double labeling experiments, the bulk of all the antigens was found in vesicles containing tightly packed membrane material…