No description available.

<p>Two methods for the measurement of micro-scale stressvariations of press felt surfaces were developed. The methodswere based on a thin plastic film that was coated with anopaque stress-sensitive layer (Cronapress conversion film). Thefilm was compressed between a felt and a smooth surface. Uponapplication of load the opaque layer became partiallytransparent at the locations where load was applied by thesurface fibres of the felt. The degree of transparency was afunction of the locally applied stress. The spatial resolutionof the method was 6.3 µm, which means that even details ofthe order of the diameter of a batt fibre diameter can beresolved.</p><p>Parameters characterising the stress variations were used toquantitatively describe the extent of the stress variations,the size of the contact areas and the distance between them.The applicability of these contact characterisation parameterswas evaluated in laboratory wet pressing experiments and inpilot paper machine trials for two sets of specially designedpress felts. In general, the dewatering result was mainlyinfluenced by the diameter of the felt surface batt fibres andby the web grammage. For a specific pulp type and operatingconditions a multivariate model was formulated based on themeasured web dryness, web grammage and each contactcharacterisation parameter. The model was able to describe thedewatering capability of the different felts tested. Contactcharacterisation parameters related to contact properties (e.g.contact area ratio) gave the best prediction for low grammagewebs, while parameters related to flow properties (e.g. size ofopenings) gave the best prediction for high grammage webs.</p><p>Furthermore it was found that at a certain web grammage, thesurface batt fibre diameter did not have an influence on thedewatering result. This grammage was termed "transitiongrammage". Below the transition grammage a fine surface gavesignificantly better dewatering, while the opposite trend wasobserved above the transition grammage. Based on these results,a modified dewatering hypothesis was formulated. Thishypothesis links the non-uniform compression of the wet webwith different dewatering situations for low and high grammagewebs.</p><p><b>Keywords</b>Press felts, Roughness, Smoothness, SurfaceStructure, Uniformity, Wet pressing, Batt fibre, Base weave,Stress variations, Micro-scale.</p>

The purpose of this dissertation was ta determine the usefulness of the linguistic processes of Distortion, Deletion, Generalization, and Semantic Ill-Formedness as constructs which differentiate the verbal communication in families who express dissatisfaction with their current intrafamilial relationships from the verbal communication in families expressing satisfaction with their current relationships. These linguistic constructs provide an intermediate link between abstract theoretical assumptions and concrete findings which abound in the field of family interaction research. Specifically, it was hypothesized that dissatisfied families would use these linguistic structures to a greater extent in their interaction than would satisfied families. Thirty-one family triads, consisting of father; mother, and child were obtained by asking families randomly selected from the local high school student directory to participate. The families were given a Revealed Differences questionnaire and a questionnaire eliciting information regarding their satisfaction with their intrafamilial relationships. The families we~e instructed to reach agreement on items of the Revealed Differences questionnaire which they had disagreed on and the discussion was tape recorded. The discussions were transcribed and each of 150 Surface Structures (a complete thought, usually a grammatical sentence) per family was scored for 11 subcategories of Distortion, Deletion, Generalization, and Semantic Ill-Formedness. Interrater reliabilities ranged from .86 to .98. A mean was computed for the questionnaire pertaining to satisfaction with family relationships. Six families who scored at least one half standard deviation below the mean comprised the "dissatisfied" family group, and six families who scored at least one half standard deviation above the mean comprised the "satisfied" family group. It was found that the dissatisfied families used significantly more Deletion (p The linguistic process of Deletion is theorized to result in impoverishing the speaker's model of the world and the behavioral choices available to the speaker. Similarly, the listener{s) who must respond to the impoverished model is limited in his response and behavioral options. Since all members of the dissatisfied families used this form of language, they perpetuate the impoverishing model of the world and the limitations on their behavior. It was concluded that, while not establishing an etiologic link between the use of Deletion and family dissatisfaction, Deletion is part of the current verbal interaction of families who express dissatisfaction. Further research involving families in which a member is symptomatic is warranted based on the findings of this study. Language may provide at least one form of explanation regarding the process by which families maintain homeostasis in the face of symptom development. The use of linguistic concepts shows promise as an intermediate link in family interaction theory as well as a form of intervention available to therapists.

ABSTRACT In this study, the properties of the high impedance surface structure are studied. We proceed to design the low profile and miniature high impedance surface structure. In order to conform to the IC chips of RFID and reduce the influence of metal objects, we add a layer of electromagnetic band-gap (EBG) structure on the back of the antenna. The EBG behaves as a high impedance surface, similar to a perfect magnetic conductor. This property of the EBG structure is able to isolate the antenna and backside environment and reduce the metallic effect. In order to achieve the requirements of small size and low cost on RFID tag antenna, we design the miniature, low profile and low cost high impedance surface structure. In this study, we use the slots and chip capacitance to miniaturize the dimension. Both approaches can reduce the influence of metallic objects. Although using slots can reduce the metallic effect, it does not have the advantage of low profile. Using chip capacitor can miniaturize the dimension and reduce metallic effect effectively. It also has advantages of low profile, low cost and low sensitivity to the frequency of the tag antenna. Finally, the high impedance surface structures are fabricated and measured when they combine with the tag antenna attached to the metallic object. The measured results agree with simulated ones well.

Two methods for the measurement of micro-scale stressvariations of press felt surfaces were developed. The methodswere based on a thin plastic film that was coated with anopaque stress-sensitive layer (Cronapress conversion film). Thefilm was compressed between a felt and a smooth surface. Uponapplication of load the opaque layer became partiallytransparent at the locations where load was applied by thesurface fibres of the felt. The degree of transparency was afunction of the locally applied stress. The spatial resolutionof the method was 6.3 µm, which means that even details ofthe order of the diameter of a batt fibre diameter can beresolved. Parameters characterising the stress variations were used toquantitatively describe the extent of the stress variations,the size of the contact areas and the distance between them.The applicability of these contact characterisation parameterswas evaluated in laboratory wet pressing experiments and inpilot paper machine trials for two sets of specially designedpress felts. In general, the dewatering result was mainlyinfluenced by the diameter of the felt surface batt fibres andby the web grammage. For a specific pulp type and operatingconditions a multivariate model was formulated based on themeasured web dryness, web grammage and each contactcharacterisation parameter. The model was able to describe thedewatering capability of the different felts tested. Contactcharacterisation parameters related to contact properties (e.g.contact area ratio) gave the best prediction for low grammagewebs, while parameters related to flow properties (e.g. size ofopenings) gave the best prediction for high grammage webs. Furthermore it was found that at a certain web grammage, thesurface batt fibre diameter did not have an influence on thedewatering result. This grammage was termed "transitiongrammage". Below the transition grammage a fine surface gavesignificantly better dewatering, while the opposite trend wasobserved above the transition grammage. Based on these results,a modified dewatering hypothesis was formulated. Thishypothesis links the non-uniform compression of the wet webwith different dewatering situations for low and high grammagewebs. KeywordsPress felts, Roughness, Smoothness, SurfaceStructure, Uniformity, Wet pressing, Batt fibre, Base weave,Stress variations, Micro-scale. / <p>QCR 20161026</p>

In this thesis, the design rule of the tag antenna and the properties of the high impedance surface structure are studied. We proceed to design the low profile and miniature high impedance surface structure. In order to be more competitive, we use PCB plates for fabrication to reduce the cost. The tags are intended to be placed inside two shorted metallic plates. In order to reduce the effect of the two parallel metallic plates, we use the slots to design the tag antenna. The EBG structure behaves as a high impedance surface and suppresses the surface wave. We add the EBG structure on the back of the antenna to reduce the back metallic effect. We use slot structure to design the non-planar RFID reader antenna that can be placed inside the three metallic plates to read the data. For the slot structure design, the electric field between the slots is perpendicular to the upper and lower metallic plates. According to the image theory, the induced image current will result in constructive effect to reduce the metallic effect. Finally, the hand-held RFID reader may not identify the RFID tag as the RFID tag placed at position deeper inside. The proposed non-planar reader can solve this problem to be used for more applications.

No description available.

Biomaterials are widely used in medical practice to help maintain, improve or restore diseased tissues or organs. The successful integration of biomaterials with host tissue depends on substratum surface properties, as well as host tissue quality and its regulatory environment. The overall goal of this dissertation is to incorporate these three factors to achieve better biomaterial-host tissue interactions. Important surface properties include surface topography, surface energy, chemical composition and surface charge. We designed a new titanium (Ti) substratum with modified surface chemical composition by preventing the contamination when in contact with the atmosphere. The new Ti surface has lower carbon contamination and promotes osteoblast differentiation phenotype. The osteogenic effect is synergistic with micrometer and sub-micrometer scale surface structures. To further investigate the effects of bone quality on peri-implant bone formation, we developed a novel mouse femoral medullary bone formation model. This new model will facilitate research evaluating the effects of biomaterial surface treatments in host animals with deficient bone development, including genetically engineered mice. Finally, we studied sexual dimorphism in the response of osteoblasts to systemic regulatory hormones 1¦Á,25-dihydroxyvitamin D3 and 17¦Â-estradiol. The results showed intrinsic differences in male and female osteoblasts with respect to their differentiation and their responses to hormones, suggesting that host chromosomal sex should be considered in biomaterial research. Taken together, this research provides fundamental information on biomaterial surface properties and the regulation of host tissue response, which are important in guiding biomaterial design and evaluation.

Thesis (B.A.(Hons.))-- University of Adelaide, Dept. of Psychology, 1980.

Thesis (doctoral)--Rijksuniversiteit te Utrecht. / Description based on print version record.