Search results for "methods"
showing 10 items of 4526 documents
Effect of Stiffness on the Micellization Behavior of Model H4T4 Surfactant Chains
2006
The micellization behavior of a series of model surfactants, all with four head and tail groups (H4T4) but with different degrees of chain stiffness, was studied using grand canonical Monte Carlo simulations on a cubic lattice. The critical micelle concentration, micellar size, and thermodynamics of micellization were examined. In all cases investigated, the critical micelle concentration was found to increase with increasing temperature as observed for nonionic surfactants in apolar or slightly polar solvents. At a fixed reduced temperature and increasing chain stiffness, in agreement with previous observations, it was found that the critical micelle concentration decreased and the average…
Effect of 3,4-dichloroaniline on the early life stages of the zebrafish (Brachydanio rerio): results of a comparative laboratory study.
1991
An early life-stage (ELS) test was conducted with the zebrafish and 3,4-dichloroaniline (3,4-DCA) in eight laboratories. Based on the results from all eight laboratories, an LOEC of 200 micrograms 3,4-dichloroaniline/liter applies for the early life stages of the zebrafish. Effects observed were reduction of the survival rate and malformations. If the 100 micrograms/liter concentration additionally tested by one laboratory is included in the assessment, an LOEC of 100 micrograms 3,4-DCA/liter is obtained for the survival rate and increase in length. The NOEC is 20 micrograms/liter. The present results of a comparative laboratory study with the zebrafish show that a 42-day ELS test can be co…
The Evergreen Project: Introduction
2003
Do aging employees benefit from self-regulative strategies? : A follow-up study
2020
SOC-strategies (selection, optimization, and compensation) are crucial for well-being and adaptation throughout the life course. The workforce is aging rapidly, thus the age-conditional premises of SOC theory require attention. This study explored (1) whether older employees used SOC strategies more often (compared to younger employees), and (2) whether older employees benefited more from SOC strategies in relation to occupational well-being (job burnout, work engagement). The study was based on follow-up data including three occupational subsamples of different age (N = 1,020). There were no significant age-conditional differences in the take-up of SOC strategies. However, older (white-col…
Changes in Postural Balance in Frail Elderly Women during a 4-Week Visual Feedback Training: A Randomized Controlled Trial
2002
<i>Background:</i> Balance training programs have not shown consistent results among older adults, and it remains unclear how different training methods can be adapted to frail elderly people. <i>Objective: </i>The purpose of this study was to investigate the effects of a 4-week visual feedback-based balance training on the postural control of frail elderly women living in residential care homes. <i>Methods:</i> Elderly women of two residential care facilities were randomized to an exercise group (EG, n = 20) and to a control group (CG, n = 7). The EG participated in training sessions three times/week for 4 weeks. The exercises were carried out with a com…
Reconstructing Bronze Age diets and farming strategies at the early Bronze Age sites of La Bastida and Gatas (southeast Iberia) using stable isotope …
2020
The El Argar society of the Bronze Age in the southeast of the Iberian Peninsula (2200–1550 cal BCE) was among the first complex societies in Europe. Its economy was based on cereal cultivation and metallurgy, it was organized hierarchically, and successively expanded its territory. Most of the monumentally fortified settlements lay on steeply sloped mountains, separated by fertile plains, and allowed optimal control of the area. Here, we explore El Argar human diets, animal husbandry strategies, and food webs using stable carbon and nitrogen isotope analysis of charred cereal grains as well as human and animal bone collagen. The sample comprised 75 human individuals from the sites of La Ba…
Occurrence and risk assessment of mycotoxins, acrylamide, and furan in Latvian beer.
2018
This work reports data on the occurrence of nine mycotoxins and two food processing contaminants - acrylamide and furan - in a total of 100 beers produced in Latvia. Mycotoxins were detected by high-performance liquid chromatography (HPLC) coupled with time-of-flight mass spectrometry, acrylamide by HPLC coupled with quadrupole-Orbitrap mass spectrometry, and furan by headspace gas chromatography-mass spectrometry. The most frequently occurring mycotoxins were HT-2 and deoxynivalenol (DON), which were detected in 52% and 51% of the analysed samples. The highest content was observed for DON, reaching the maximum of 248 µg kg-1. Furan was ubiquitous, and 74% of the samples contained acrylamid…
Stubborn sets, frozen actions, and fair testing
2021
Many partial order methods use some special condition for ensuring that the analysis is not terminated prematurely. In the case of stubborn set methods for safety properties, implementation of the condition is usually based on recognizing the terminal strong components of the reduced state space and, if necessary, expanding the stubborn sets used in their roots. In an earlier study it was pointed out that if the system may execute a cycle consisting of only invisible actions and that cycle is concurrent with the rest of the system in a non-obvious way, then the method may be fooled to construct all states of the full parallel composition. This problem is solved in this study by a method tha…
New Families of Symplectic Runge-Kutta-Nyström Integration Methods
2001
We present new 6-th and 8-th order explicit symplectic Runge-Kutta-Nystrom methods for Hamiltonian systems which are more efficient than other previously known algorithms. The methods use the processing technique and non-trivial flows associated with different elements of the Lie algebra involved in the problem. Both the processor and the kernel are compositions of explicitly computable maps.
Studi greci e latini nell?antica Università di Altamura (1748-1821)
2019
The article tries to highlight, despite the scarse of available documentation, the Greek and Latin studies (language and texts) in the ancient Apulian University in Altamura (1748-1821). Furthermore, on the basis of unpublished archival materials (school registers and student workbooks) it is possible to shed light on the ancient authors explained at school, the teaching methods, and the study practices.