Direct frequency changer operation under a new scalar controlalgorithm

A thorough analysis of a scalar control method for the operation of direct frequency changers (DFC) using bidirectional switches operating at high switching frequencies is proposed. The method allows full control over voltage and frequency at the output port and the input side power displacement factor, with little effect on the frequency spectrum of either the output voltage or input currents. The method uses the instantaneous voltage ratio of specific input phase voltages to generate the active and zero states of the various switches. A voltage transfer ratio as high as 0.87 is obtained under synchronous and asynchronous operation with a conventionally connected three-phase load. Analysis shows that the input power displacement factor is independent of load characteristics. The power displacement can be precisely controlled by proper adjustments of the timing sequence. Synchronization error in the timing sequence affects both the input power displacement and the voltage transfer ratio     

Selective CO-oxidation over Ru-based catalysts in H2-rich gas for fuel cell applications

Topics in Catalysis - Ru-based catalysts supported on A zeolites and alumina were synthesised, characterised (XRD, SEM-EDS, TPR) and tested under realistic conditions for the preferential oxidation...     

Issues and Implications of Deaf Culture in Therapy.

In the United States, it is estimated that between 200,000 and 500,000 individuals are culturally Deaf. Deaf culture provides unique challenges that can impact standard therapeutic techniques. Issues regarding the ability of hearing therapists to effectively work with Deaf clients are addressed, and a number of guidelines are offered to assist hearing therapists in bridging language barriers and cultural gaps with Deaf clients. Additionally, concerns about the selection and inclusion of sign language interpreters are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Family resemblance in attitudes to foods.

Although it seems likely that family experience should be a major factor in the acquisition of food preferences and attitudes to foods, prior research has not justified assignment of a significant portion of variance to family influences. The present study compared young adults with their parents and explored attitudes to food, especially sensitivity to cleanliness and contamination of foods, as well as food preferences. Questionnaires were answered by 17 Christian and 17 Jewish university students, their parents, and 41 11–36 yr old siblings. Results indicate small positive parent–child correlations for food preferences and considerably larger correlations in the area of disgust or contamination sensitivity. Children's preferences and attitudes were about equally related to those of their mother and father. Some small ethnic-group effects were found in contamination sensitivity; these were minor in comparison to the family effects. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are adult children of dysfunctional families with alcoholism different from adult children of dysfunctional families without alcoholism? A look at committed, intimate relationships.

Investigating the validity of classifying adult children of dysfunctional families with alcoholism (ACDFAs) as a unique population, this study compared ACDFAs with adult children of dysfunctional families without alcoholism (ACDFs) and adult children of functional families (ACFFs) on current relationship satisfaction. Participants (N ?=?126) were from a community sample. No significant difference between the ACDFAs and ACDFs was found; however, both ACDFAs and ACDFs displayed significantly more difficulty with problem-solving communication than the ACFFs. Regression results indicated that dysfunction in the family of origin is significantly related to global distress and difficulties with problem-solving communication in current intimate relationships. Results do not lend support to the utility of classifying ACDFAs as a unique population. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Embedding deductive capabilities in relational database systems

The basic idea of our work is to include deductive capabilities in a relational database system by fully using the operands of relational algebra and without using any theorem prover. We present a deductive database system where the user can formulate deduction laws as logical formulas, but which works on an underlying relational database system by fully using the data manipulation routines of such a system. Generally, it is not possible to express the deduction laws by means of expressions of relational algebra (see Ref. 1). In our system, a relational algebra expression is associated with every database deduction law. The result of its evaluation (with respect to an underlying database) is the set of all database entries that can be deduced from the database by applying the respective law once (Theorem 1). By successively applying all these relational expressions for all the database deduction laws it is possible to generate the whole extensional database (i.e. all tuples deducible from the database).     

Adsorption of antifouling booster biocides on metal oxide nanoparticles: Effect of different metal oxides and solvents

Controlling the release rate of biocides (antifouling agents) from a paint coating is a key issue for the development of multi-season antifouling marine coatings. One promising approach is the use of nanoparticles onto which biocides are adsorbed to prevent premature depletion of the biocide. Adsorption of one novel (Medetomidine) and six commercially available and widely used antifouling biocides (Chlorothalonile, Dichlofluanid, Diuron, Irgarol, Seanine, Tolylfluanid) onto oxide nanoparticles (Al₂O₃, CuO, MgO, SiO₂, TiO₂, ZnO) was investigated by HPLC and NMR in different organic solvents. Large differences in adsorption strength depending on the type of nanoparticle and solvent employed were observed. It was shown that nanoparticles coordinate preferentially with the imidazole moiety of Medetomidine. Independent of the type of particle this interaction was considerably stronger in comparison to the other biocides. However, the interaction strength was strongly dependant on the type of solvent, where the largest strongest interaction was achieved in o-xylene. In addition field tests were performed where a considerable decrease in release rate was displayed from coatings containing Medetomidine adsorbed to nanoparticles compared to coatings containing Medetomidine as single additive.