Validity of the Acti4 software using ActiGraph GT3X+accelerometer for recording of arm and upper body inclination in simulated work tasks

The validity of inclinometer measurements by ActiGraph GT3X+ (AG) accelerometer, when analysed with the Acti4 customised software, was examined by comparison of inclinometer measurements with a reference system (TrakStar) in a protocol with standardised arm movements and simulated working tasks. The sensors were placed at the upper arm (distal to the deltoid insertion) and at the spine (level of T1-T2) on eight participants. Root mean square errors (RMSEs) values of inclination between the two systems were low for the slow- and medium-speed standardised arm movements and in simulated working tasks. Fast arm movements caused the inclination estimated by the AG to deviate from the reference measurements (RMSE values up to ～10°). Furthermore, it was found that AG positioned at the upper arm provided inclination data without bias compared to the reference system. These findings indicate that the AG provides valid estimates of arm and upper body inclination in working participants.     

Rheological properties of pH-induced association and gelation of pectin

Summary Pectin is an important polysaccharide with applications in food industry, cosmetics and pharmacy. In recent years, there has been an increased use of hydrogels in pharmaceutical formulations in connection with drug-delivery administration. In this study of aqueous pectin systems, association and gelation have been accomplished by changing pH of the samples to an acidic pH. This is carried out by adding glucono-δ-lactone (GDL), which will gradually reduce the pH of the system. As the pH is reduced, the carboxyl acid groups on the pectin chains are neutralized, and the polyelectrolyte character of the polymer is reduced promoting association and gelation of the system. The viscoelastic properties of the system are monitored by oscillatory shear measurements as a function of time after the addition of GDL. The system exhibits very long gelation times and a pronounced viscosity increase in the vicinity of the gel points.     

Acyl group distributions in tissue lipids of rats fed evening primrose oil (λ-linolenic plus linoleic acid) or soybean oil (α-linolenic plus linoleic acid)

Three groups of rats were fed diets with either 10 weight percent (wt%) of evening primrose oil, safflower oil or soybean oil for 11 weeks. Diets contained 7.1 wt% linoleic acid +0.8 wt% γ-linolenic acid, 7.6 wt% linoleic acid, or 5.3 wt% linoleic acid +0.7 wt% α-linolenic acid, respectively. In liver mitochondria as well as in heart, dietary γ-linolenic acid did not affect the fatty acid profiles of phosphatidylcholnes (PC), phosphatidylethanolamines (PE) or cardiolipins (CL), whereas dietary α-linolenic acid caused an increased formation of (n−3) polyunsaturated fatty acids (PUFA). The liver Δ6− and Δ5-desaturase activities determined in vitro were not affected by the dietary fats. In brain PE, which are rich in C22− and C20-(n−3) PUFA, as well as in testes PC and PE, which are rich in (n−6) PUFA, no effects were found from a partial replacement of dietary linoleic acid with γ-linolenic acid or α-linolenic acid. In kidney PC, PE, phosphatidylinositol (PI) and CL, 20∶3(n−6) was moderately elevated to ca. 1% following intake of γ-linolenic acid, whereas partial replacement of linoleic acid with α-linolenic acid was followed by increased deposition of 22∶6(n−3) in PC and PE of testes and kidney. Thus, no general effect of evening primrose oil on the content of (n−6) PUFA in rat tissue phospholipids was observed, wheras a significant incorporation of γ-linolenic acid into liver and adipose tissue triglycerides was found.     

Dynamic modelling of a gas phase catalytic fixed-bed reactor—I: Experimental apparatus and determination of reaction kinetics

A large scale fixed bed pilot reactor for performing dynamic experiments is described. The reactor system is especially designed to suppress secondary dispersion effects not characteristic for the packed bed itself.As a model reaction the reaction between oxygen (<1%) and hydrogen on a platinum catalyst supported by alumina has been used.Differential reactor experiments disclosed a hysteresis phenomenon in the catalyst activity. The catalyst is generally more active when going from high to low temperatures than vice versa.A global first order reaction rate expression with Arrhenius temperature dependency fits the fixed-bed reactor profiles well but the static gains badly. However by simultaneous estimation of frequency factor and activation energy in several axial segments a much better approximation to the static gains was obtained. This result indicates that the reaction kinetics is more complicated than first assumed. However for dynamic modelling the exact reaction mechanism is not needed.     

Understanding the Effect of Steps, Strain, Poisons, and Alloying: Methane Activation on Ni Surfaces

Platinum–Cobalt-loaded NaY zeolite (Pt–Co/NaY) membranes were synthesized for continuous, single-step nonoxidative conversion of methane to higher hydrocarbons (C₂₊) and hydrogen. During isothermal operation at 300 °C, CH₄ flowed on the feed side of the membrane whilst H₂ flowed through the sweep side of the membrane. The C₂₊ products formed continuously on the H₂ sweep side. The results indicate that the Pt–Co/NaY catalytic membrane can overcome the two-step limitation for nonoxidative CH₄ conversion.     

Approaches for the combined use of risk analysis and testing: a systematic literature review

Risk analysis and testing are conducted for different purposes. Risk analysis and testing nevertheless involve processes that may be combined to the benefit of both. We may use testing to support risk analysis and risk analysis to support testing. This paper surveys literature on the combined use of risk analysis and testing. First, the existing approaches are identified through a systematic literature review. The identified approaches are then classified and discussed with respect to main goal, context of use and maturity level. The survey highlights the need for more structure and rigor in the definition and presentation of approaches. Evaluations are missing in most cases. The paper may serve as a basis for examining approaches for the combined use of risk analysis and testing, or as a resource for identifying the adequate approach to use.     

Modelling of N-movements on catchment scale - a tool for analysis and decision making

The modelling system described by Styczen and Storm (1993) simulates nitrogen transformation as well as water and nitrogen transport on a regional scale and can be used to evaluate effects of changes in the land use or in agricultural practices on the water quality in the groundwater and in the streams. It may be used to evaluate variations in time and space, and to predict the time lag from new strategies are implemented until measurable results are obtained. A case study was carried out on the 425 km² large Karup River catchment in Denmark for the period 1968–88, and the paper presents the data required to set up the model and results from the simulations. Most of the data and information required could be extracted from existing databases, reports, and statistical yearbooks while information on changes in management practices came from local agricultural advisers. The simulations are compared to measurements in part of the Karup River catchment.     

Vector Spaces as the Basic Component of Interactive Systems: Towards a Computer Semiotics

The practical point of departure is design and implementation of interactive multimedia applications. The focus is on the aesthetic aspects, ranging from graphical display to narratives structures. In particular, I am interested in developing a theory of narration that exploits the special dynamic characteristics of computer systems, namely that the reader can interact with the system and the system can act itself. It is suggested that a vector space consisting of objects and vectors can form the basis for such a theory; its basic narrative unit is the vector, a force emanating from an object that either attracts other objects or repels them. An interactive multimedia product will contain sets of vector spaces, each with a simple internal structure but with the ability to generate a richness of events, most of which may not even have occurred to the author. The paper presents arguments in favor of the vector in the domain of interactive narratives and public information systems. A final section suggests that René Thom's catastrophe theory may provide at theoretical basis for the ideas.     

A collection operator for graph transformation

Algebraic graph transformation has a wellestablished theory and associated tools that can be used to perform model transformations. However, the lack of a construct to match and transform collections of similar subgraphs makes graph transformation complex or even impractical to use in a number of transformation cases. This is addressed in this paper, by defining a collection operator which is powerful, yet simple to model and understand. A rule can contain multiple collection operators, each with lower and upper bound cardinalities, and the collection operators can be nested. An associated matching process dynamically builds a collection free rule that enables us to reuse the existing graph transformation apparatus. We present model transformation examples from different modeling domains to illustrate the benefit of the approach.