Search results for "Overall efficiency"
showing 10 items of 11 documents
Relative Efficiency of Two Models of Ugglan Special Live-Traps for Capturing Small Rodents in Boreo-Nemoral Forest
2018
Live trapping is an invaluable and commonly used technique for studying small mammal populations. There are several types of commercially available live-traps, but some models have been shown to differ in terms of species-specific efficiency. Such differences could lead to biased results, and knowledge of such bias is important when comparing results of different studies. The Ugglan Special live-trap is one commonly used type, and it is available in several different models. I studied performance of the two most common models (No. 1 and No. 2) to find out whether they differ in terms of overall efficiency and body-mass-dependent efficiency, when trapping small rodents. I used 48 traps of ea…
SCCF Parameter and Similarity Measure Optimization and Evaluation
2019
Neighborhood-based Collaborative Filtering (CF) is one of the most successful and widely used recommendation approaches; however, it suffers from major flaws especially under sparse environments. Traditional similarity measures used by neighborhood-based CF to find similar users or items are not suitable in sparse datasets. Sparse Subspace Clustering and common liking rate in CF (SCCF), a recently published research, proposed a tunable similarity measure oriented towards sparse datasets; however, its performance can be maximized and requires further analysis and investigation. In this paper, we propose and evaluate the performance of a new tuning mechanism, using the Mean Absolute Error (MA…
Insights into how nucleotide supplements enhance the peroxidase-mimicking DNAzyme activity of the G-quadruplex/hemin system
2012
Since the initial discovery of the catalytic capability of short DNA fragments, this peculiar enzyme-like property (termed DNAzyme) has continued to garner much interest in the scientific community because of the virtually unlimited applications in developing new molecular devices. Alongside the exponential rise in the number of DNAzyme applications in the last past years, the search for convenient ways to improve its overall efficiency has only started to emerge. Credence has been lent to this strategy by the recent demonstration that the quadruplex-based DNAzyme proficiency can be enhanced by ATP supplements. Herein, we have made a further leap along this path, trying first of all to deci…
Recent developments in and applications of resonance ionization mass spectrometry
1999
Resonance Ionization Mass Spectrometry (RIMS) has nowadays reached the status of a routine method for sensitive and selective ultratrace determination of long-lived radioactive isotopes in environmental, biomedical and technical samples. It provides high isobaric suppression, high to ultra-high isotopic selectivity and good overall efficiency. Experimental detection limits are as low as 106 atoms per sample and permit the fast and sensitive determination of ultratrace amounts of radiotoxic contaminations. Experimental arrangements for the detection of different radiotoxic isotopes, e.g. 236–244Pu, 89,90Sr and 99Tc in environmental samples are described, and the application of RIMS to the ul…
Agricultural externalities and environmental regulation: evaluating good practice in citrus production
2006
Economic activity takes place in a scenario characterized by an increasing number of environmental regulations aimed at bringing under control the emission of contaminating wastes. In this paper, we evaluate the impact of transforming a code of good practice in nitrogen fertilization on Spanish citrus fruit farms into an environmental regulation of compulsory fulfilment. Using data envelopment techniques, we calculate unrestricted and environmentally regulated short-run maximum profits. Both profit values are then used to compute an index of the cost of regulation. Our results suggest that the cost of shifting from a merely recommended practice to a binding rule is low. On average, the loss…
First experimental results of a cryogenic stopping cell with short-lived, heavy uranium fragments produced at 1000 MeV/u
2013
A cryogenic stopping cell (CSC) has been commissioned with U-238 projectile fragments produced at 1000 MeV/u. The spatial isotopic separation in flight was performed with the FRS applying a monoenergetic degrader. For the first time, a stopping cell was operated with exotic nuclei at cryogenic temperatures (70 to 100K). A helium stopping gas density of up to 0.05mg/cm(3) was used, about two times higher than reached before for a stopping cell with RF ion repelling structures. An overall efficiency of up to 15%, a combined ion survival and extraction efficiency of about 50%, and extraction times of 24ms were achieved for heavy a-decaying uranium fragments. Mass spectrometry with a multiple-r…
The on-line isotope separation facility helios at the mainz reactor
1980
Abstract The on-line isotope separation facility HELIOS consisting of a helium-jet transport system coupled to a high transmission mass separator is described. The main characteristics of the system were determined from γ-ray measurements on neutron-rich nuclides. The transmission from the target to the skimmer is about 60%; the overall efficiency for typical fission product elements is 0.05–0.2% and the transit time for Cs is about 1.0 s.
Simulation and experimental investigations on dynamic after cavity interaction (ACI)
2010
In recent years, the so called after cavity interaction (ACI) in high power gyrotrons operating in the 100–200 GHz range gained attention as an influence factor on overall efficiency. While investigations concentrated on ACI as a stationary effect until now, recent simulations show that an undesired interaction in the uptaper region can also result in additional parasitic oscillations. In this paper, such non-stationary, dynamic processes are investigated in first simulations and experiments.
Enantioselective Total Syntheses of (+)-Hippolachnin A, (+)-Gracilioether A, (-)-Gracilioether E, and (-)-Gracilioether F.
2018
The Plakortin polyketides represent a structurally and biologically fascinating class of marine natural products. Herein, we report a unified strategy that enables the divergent syntheses of various Plakortin polyketides with high step-economy and overall efficiency. As proof-of-concept cases, the enantioselective total syntheses of (+)-hippolachnin A, (+)-gracilioether A, (-)-gracilioether E, and (-)-gracilioether F have been accomplished based on a series of bio-inspired, rationally designed, or serendipitously discovered transformations, which include (1) an organocatalytic asymmetric 1,4-conjugate addition to assemble the common chiral γ-butenolide intermediate enroute to all of the afo…
Competencias para la innovación en las universidades de América Latina: un análisis empírico
2010
Los egresados universitarios constituyen, en cualquier país, el grupo social que acumula un mayor volumen de capital humano debido a que su trayectoria educativa ha sido más prolongada y ha requerido una fuerte inversión. La premisa de esta investigación es que el potencial de innovación que aportan estos egresados es un determinante fundamental tanto para el éxito en su trayectoria profesional como para la eficiencia total de los sistemas de producción en los distintos países. Para su realización, se dispuso de una amplia base de datos provenientes de la macro encuesta PROFLEX realizada a unos 10 000 egresados universitarios latinoamericanos a la que se ha aplicado una estimación de funcio…