Search results for "intensity"
showing 10 items of 1091 documents
Theoretical absorption spectrum of the Ar–CO van der Waals complex
2003
The three-dimensional intermolecular electric dipole moment surface of Ar–CO is calculated at the coupled cluster singles and doubles level of theory with the aug-cc-pVTZ basis set extended with a 3s3p2d1f1g set of midbond functions. Using the rovibrational energies and wave functions of our recent study [J. Chem. Phys. 117, 6562 (2002)], temperature-dependent spectral intensities are evaluated and compared to available experimental data. Based on the theoretical spectrum, alternative assignments of the experimentally observed lines in the fundamental band of CO around 2160 and 2166 cm−1 are suggested. Thomas.Bondo@uv.es
Fatigue crack growth through particulate clusters in polycarbonate material
2011
The interaction of a crack with a perfectly bonded inclusion or a cluster of inclusions in polycarbonate matrix was investigated through both numerical simulations and fatigue tests. Stress intensity factors (K(I)) were evaluated by boundary element method for several particle sizes, position and finally for inclusion cluster as a precursor study for the experiments. The numerical simulation has shown the crack tendency to circumvent the inclusions with consequential reduction of the growth rate. Fatigue crack growth tests were carried out on several particle-filled specimens at constant value of the applied stress intensity factor range (Delta K(Iapp)) highlighting the crack delay due to t…
FATIGUE CRACK PROPAGATION THROUGH AUSTEMPERED DUCTILE IRON MICROSTRUCTURE
2010
Austempered ductile iron (ADI) has a wide range of application, particularly for castings used in automotive and earth moving machinery industries. These components are usually subjected to variable dynamic loading that may promote initiation and propagation of fatigue cracks up to final fracture. Thus, it is important to determine the fatigue crack propagation behavior of ADI. Since fatigue crack growth rate (da/dN) vs. stress intensity factor K data describe fatigue crack propagation resistance and fatigue durability of structural materials, da/dN vs. Ka curves of ADI 1050 are reported here. The threshold amplitude of stress intensity factor Kath is also determined. Finally, the influence…
Irrigation water intensity and climate variability: an agricultural crops analysis of Italian regions
2020
This paper examines the relationship between the requirement of water resources for irrigation and climate variability and analyses the ranking of the best and worst performance of irrigation water intensity for each Italian region. To measure water resources demanded by agriculture, the irrigation water intensity (IWI) indicator has been computed as the ratio between volumes of irrigation water and total crop harvested. By applying panel data methodologies to a regional dataset spanning from 2000 to 2009, we may address heterogeneity and omitted variable issues. By merging meteo-climatic with agricultural variables, we may confirm that water precipitations, maximum temperature, irrigation …
Estudio climático del exponente “n” de las curvas IDF: aplicación para la Península Ibérica
2009
El análisis de las precipitaciones máximas suele llevarse a cabo mediante curvas IDF (Intensidad-Duración-Frecuencia), que a su vez pueden expresarse como curvas IMM (Intensidades Medias Máximas). En este trabajo, hemos desarrollado un índice “n”, definido a partir del exponente que se obtiene de ajustar las curvas climáticas IDF a las curvas IMM. Dicho índice proporciona información sobre el modo en que se alcanzan las precipitaciones máximas en una determinada zona clim´atica, atendiendo a la distribuci´on temporal relativa de las intensidades m´aximas. A partir del an´alisis clim´atico del ´ındice “n”, en la Pen´ınsula Ib´erica se pueden distinguir grandes zonas caracterizadas por m´axim…
The Variability of the Photosynthetic Unit in Chlorella Fusca
1984
The concept of the photosynthetic unit (PSIT) was introduced by Gaffron and Wohl (1936) on the basis of Emerson and Arnold’s flash light experiments (1932). The PSU was defined as the minimum of chlorophyll molecules required for the evolution of one O2. Later on, the PSU was considered to be the complex of one reaction center and its appropriate antenna of light harvesting chlorophyll molecules. Assuming that there is an equal number of the PS I and PS II reaction centers the PSU was mostly expressed as Chl/P-700. However, recently it could be shown that the ratio of PS II/PS I is variable depending on the light conditions during growth (Kawamura et al., 1979; Myers, Graham, 1982). Further…
The Effect of Blue and Red Light on the Content of Chlorophyll, Cytochrome f, Soluble Reducing Sugars, Soluble Proteins and the Nitrate Reductase Act…
1980
The photosynthetic characteristics of many species of plants are influenced by the light intensity under which the plant is grown. This is shown by the light saturation curves for CO2 uptake. Both the light intensity required for saturation and the light-saturated rate of CO2 uptake increase with the light intensity under which the plant is grown. Photosynthetic adaptation to different light levels involves balanced changes of many leaf factors. Low-light and high-light plants differ in a number of component steps of photosynthesis as well as in the structure and composition of the photosynthetic apparatus and in the leaf anatomy (see reviews by Boardman 1977; Wild 1979).
On the accuracy of the fast hierarchical DBEM for the analysis of static and dynamic crack problems
2010
In this paper the main features of a fast dual boundary element method based on the use of hierarchical matrices and iterative solvers are described and its effectiveness for fracture mechanics problems, both in the static and dynamic case, is demonstrated. The fast solver is built by representing the collocation matrix in hierarchical format and by using a preconditioned GMRES for the solution of the algebraic system. The preconditioner is computed in hierarchical format by LU decomposition of a coarse hierarchical representation of the collocation matrix. The method is applied to elastostatic problems and to elastodynamic cases represented in the Laplace transform domain. The application …
Physical activity volume and intensity distribution in relation to bone, lean and fat mass in children.
2022
Funder: City of Kuopio
Role of photoactive layer morphology in high fill factor all-polymer bulk heterojunction solar cells
2011
We report on the realization of all-polymer solar cells based on blends of poly(3-hexylthiophene-2,5-diyl) (P3HT) as a donor and poly{[N,N'-bis(2-octyldodecyl)-naphthalene-1,4,5,8-bis(dicarboximide)-2,6-diyl]-alt-5,5'-(2,2'-bithiophene)} (P(NDI2OD-T2)) as an acceptor. High fill factors are demonstrated for the first time in this class of devices suggesting high dissociation efficiency for the bounded electron-hole pairs and balanced electron and hole mobility along the thin films. The use of the high-mobility n-type P(NDI2OD-T2) polymer enables us to overcome one of the problems limiting the efficiency of all-polymer solar cells, resulting in fill factors comparable with those reported for …