Search results for "efficient"

A ballistometer for the study of the plasto-elastic properties of skin.

1977

The ballistrometer is based on the "drop impact" of a body onto a stationary surface. A collision in one dimension is provoked by allowing a bard body to drop from a given height onto the skin surface to be tested. After the collision, the impacting body undergoes a variable number of rebounds decreasing in amplitude. By measuring the height of the rebounds, the amount of energy returned by the tissue is calculated in terms of coefficient of restitution e. The equipment, consisting of a hammer unit, a feeder-amplifier, and a plotter, is described. Ballistometry has been carried out on skin areas of 46 normal subjects ranging in age from 8 to 80 years, as well as on pathologic and cadaveric …

Multicenter validation of the magnetic resonance t2* technique for segmental and global quantification of myocardial iron

2009

Purpose To assess the transferability of the magnetic resonance imaging (MRI) multislice multiecho T2* technique for global and segmental measurement of iron overload in thalassemia patients. Materials and Methods Multiecho T2* sequences were installed on six MRI scanners. Five healthy subjects (n = 30) were scanned at each site; five thalassemia major (TM) patients were scanned at the reference site and were rescanned locally (n = 25) within 1 month. T2* images were analyzed using previously validated software. Results T2* values of healthy subjects showed intersite homogeneity. On TM patients, for global heart T2* values the correlation coefficient was 0.97, coefficients of variation (CoV…

Detecting crop water requirement indicators in irrigated agroecosystems from soil water content profiles: An application for a citrus orchard.

2022

Abstract Most perennial crops sensitive to water scarcity, such as citrus, can benefit from efficient water management, which allows for reduced water consumption while increasing crop production on a long-term basis. However, when implementing water-saving strategies, it is necessary to monitor soil and/or plant water status in order to determine crop water demand. A plethora of devices providing indirect measurements of volumetric soil water content, such as the “drill and drop” multi-sensors probes (Sentek, Inc., Stepney, Australia), have been developed over the last decade. The objective of the paper was to analyse time-series of soil water content profiles and meteorological data colle…

Temperature dependent properties of environmentally important synthetic musks.

2002

Environmental fate determining physical properties including their temperature dependence for five nitro musks and for seven polycyclic musks were estimated. The properties evaluated were vapor pressure in a solid and liquid state (PS and PL), solubility in water (S), Henry's law coefficient (H = PL/S) and log octanol-water partition coefficient (log KOW). Gas chromatography for starting values of vapor pressure estimation and HPLC experiments at 5-20 degrees C for comparison of the theoretical versus experimental solubilities in water were performed. The values of temperature (T) dependence coefficients (Ai and Bi) in equations: log (Property)i = Ai - Bi/T were determined. Values of proper…

Energy efficiency in Spanish wastewater treatment plants: a non-radial DEA approach.

2011

Wastewater treatment plants (WWTPs) are energy-intensive facilities. Thus, reducing their carbon footprint is particularly important, both economically and environmentally. Knowing the real operating energy efficiency of WWTPs is the starting point for any energy-saving initiative. In this article, we applied a non-radial Data Envelopment Analysis (DEA) methodology to calculate energy efficiency indices for sampling of WWTPs located in Spain. In a second stage analysis, we examined the operating variables contributing to differences in energy efficiency among plants. It is verified that energy efficiencies of the analyzed WWTPs were quite low, with only 10% of them being efficient. We found…

ESR response to gamma-rays of alanine pellets containing B(OH)3 or Gd2O3.

2007

ESR response to gamma-irradiation (1-50 Gy) of blends containing alanine and either B(OH)(3) or Gd(2)O(3) is reported. The sensitivity of the alanine--B(OH)(3) blend is comparable to the sensitivity of pure alanine, although its lowest detectable dose, LDD, is smaller ( approximately 1.3 Gy) than that of pure alanine ( approximately 2.9 Gy). Alanine with Gd(2)O(3) is about two times more sensitive than pure alanine, and its LDD is 0.8 Gy. The better sensitivity and LDD are probably due to the high atomic number (Z=64) of gadolinium, which enhances the interaction probability with photons and, consequently, the radical yield. This study suggests that other high-Z atoms may be useful for incr…

Isobaric Vapor−Liquid Equilibrium in the Systems 2,3-Dimethylpentane + Methyl 1,1-Dimethylethyl Ether, + Diisopropyl Ether and + Methyl 1,1-Dimethylp…

1999

New, consistent vapor−liquid equilibrium data for the binary systems 2,3-dimethylpentane + methyl 1,1-dimethylethyl ether, + diisopropyl ether, and + methyl 1,1-dimethylpropyl ether are reported at 101.3 kPa. The measured systems deviate slightly from ideal behavior, and only the system methyl 1,1-dimethylpropyl ether + 2,3-dimethylpentane presents an azeotrope. The activity coefficients for the solutions were correlated with their compositions by the Wilson, UNIQUAC, and NRTL models. Wisniak−Tamir equations were used to correlate the boiling points of the solutions with their compositions.

1988

Deviations in the determination of the unperturbed dimensions of polymers arising in ternary polymer systems (solvent (1)/solvent (2)/polymer) can be explained by the inaccurate use of an interaction parameter independent of polymer molecular weight. On this basis, a new formalism for the calculation of the second virial coefficient from intrinsic viscosity is proposed. This formalism was tested (and compared with well established formalisms) for all ternary polymer systems with simultaneous intrinsic viscosity and second virial coefficient data in the literature.

1987

The intrinsic viscosities, [η], for the ternary systems alkane (1)/2-butanone (2)/poly(dimethylsiloxane) (PDMS)(3), with the alkanes decane, dodecane and hexadecane, are determined at 20,0°C. The constants a of the Mark-Houwink equation and the constant of the unperturbed dimensions, KΘ, of the polymer are evaluated over the whole composition range of the binary solvent mixture. [η] shows a pronounced maximum at intermediate compositions as found in cosolvent mixtures. In these cosolvent mixtures, the numerical values of KΘ are higher than in the single-component solvents, because the cosolvent mixtures correspond to a mixed solvent with an excess free energy, GE ≥ 0, the increase in KΘ bei…

A Combination of Visible-Light Organophotoredox Catalysis and Asymmetric Organocatalysis for the Enantioselective Mannich Reaction of Dihydroquinoxal…

2019

[EN] An enantioselective photooxidative Mannich reaction of dihydroquinoxalinones with ketones by the merger of organophotoredox and asymmetric organocatalysis is described. This protocol features very mild reaction conditions using simple and cheap catalysts (Eosin Y and (S)-Proline) for the synthesis of chiral quinoxaline derivatives with good to high yields (up to 94%) and excellent enantioselectivities (up to 99% ee).