bluuebunny/crossref_metadata_2025_split huggingface dataset:
Filmsieden bei der Umströmung der endlichen ebenen Platte durch inkompressible Flüssigkeiten
Authors: Schütte V. 
Published: June 2007

AbstractIm Rahmen der Grenzschichttheorie wird mit Hilfe der Methode der Integralsätze für den Impuls‐ und Wärmeaustausch die Umströmung der endlichen ebenen Platte, insbesondere die Strömung im Nachlauf der Platte berechnet. Zur Bestimmung der Dampffilmlänge wird eine Extrapolationsformel angegeben.
Eindimensionale elektrothermische Prozesse und Randwertaufgaben für eine Differentialgleichung 2. Ordnung
Authors: Schleiff M. 
Published: June 2007

AbstractEin elektrothermischer Prozeß wird durch die gekoppelten Bilanzgleichungen für das elektrische und das thermische Feld beschrieben. Im stationären, eindimensionalen Fall lassen sich diese Gleichungen zu einer Randwertaufgabe für eine nichtlineare Differentialgleichung 2. Ordnung zusammenfassen. Als Parameter sind in dieser Gleichung die Stromstärke oder die Spannung enthalten, die in ihrer Abhängigkeit voneinander die Strom‐Spannungs‐Kennlinie bilden. Für diese Kennlinie wird eine Integralformel angegeben, durch deren Diskussion sich Aussagen über die Lösbarkeit der Randwertaufgabe herleiten lassen. Dann wird die inverse Aufgabe betrachtet, die Bestimmung der elektrischen Leitfähigkeit als Funktion der Temperatur aus der Strom‐Spannungs‐Kennlinie. Für diese Aufgabe wird durch eine Abelsche Integralgleichung eine geschlossene Lösung konstruiert.
The Multi‐Grid Method in the Solution of Time‐Dependent Nonlinear Partial Differential Equations
Authors: De Vries H. B. 
Published: June 2007

AbstractThe numerical solution of nonlinear, time‐dependent partial differential equations is discussed. By applying the method of lines such a partial differential equation is converted into a system of ordinary differential equations to which an implicit linear multistep method is applied. Using Newton iteration the nonlinear implicit relations are replaced by a sequence of linear equations. These linear equations are solved by the iterative use of a multi‐level algorithm. Numerical examples are given and a comparison is made with other integration techniques.
Beitrag zur tensoriellen Verallgemeinerung einachsiger Stoffgesetze
Authors: Betten J. 
Published: June 2007

AbstractIm Aufsatz wird ein Verfahren vorgeschlagen, das eine unmittelbare Übertragung beliebiger einachsiger Stoffgesetze auf eine tensorwertige Funktion gestattet. Benutzt wird eine Interpolationsmethode für Tensorfunktionen, die vom Verfasser bereits in einem früheren Aufsatz vorgestellt wurde. Als Beispiele werden das Norton‐Baileysche Kriechgesetz und die nichtlineare Dehnungs‐Spannungsbeziehung von Ramberg und Osgood tensoriell verallgemeinert.
Über Druckschwankungen in homogener isotroper Turbulenz
Authors: Szablewski W. 
Published: June 2007

AbstractAuf der Basis des Ähnlichkeitsgesetzes des Spektrums der Turbulenzenergie im Trägheitsbereich k « k0 (k0 Wellenzahl der großen Wirbel) werden Ähnlichkeitsgesetze für die Spektren des mittleren Quadrats der Druckschwankungen und der Schwankungen des Druckgradienten im genannten Bereich hergeleitet. Für die Maxima und ihre Wellenzahlen erhalten wir Potenzgesetze in der Reynoldsschen Zahl Reλ. Der Ermittlung der Zweipunktkorrelation der Druckschwankungen im Trägheitsbereich r » r0 (r0 Breite der Korrelation) wird dann das Ähnlichkeitsgesetz des Spektrums der Druckschwankungen zugrundegelegt. Es resultiert eine Ähnlichkeitsstruktur. Empirisches Element der Theorie ist die universelle Konstante des ‐ 7/3‐Potenzgesetzes des Spektrums der Druckschwankungen.
Generalized Predictor‐Corrector Methods of High Order for the Time Integration of Parabolic Differential Equations
Authors: van Der Houwen P. J. , Sommeijer B. P. , De Vries H. B. 
Published: June 2007

AbstractA general class of predictor‐corrector methods is presented and explicit expressions for the local truncation error and the stability polynomial are derived. Examples of methods of orders up to 6 are given which are suitable for the integration of semi‐discrete parabolic differential equations. By a large number of numerical experiments we show that the higher order methods are generally more efficient than the lower order methods. As a further illustration we compare the generalized predictor‐corrector methods with the familiar ADI Method confirming our general belief that for smooth parabolic problems high order time integrators are superior to lower order integrators.
On the Disturbance Attenuation andH∞‐Optimization in Structural Analysis
Authors: Zacharenakis E. C. 
Published: June 2007

AbstractIn this paper the disturbance attenuation andH∞‐optimization problems of civil engineering structures via state feedback are investigated. Here the civil engineering structures are considered to be assembled from finite elements obeying linear material laws, their displacements being small and the number of inputs (control forces) being equal to the number of outputs (displacements). The theory of disturbance attenuation andH∞‐optimization problems is introduced, for the first time, to control the civil engineering structures.
Changes in facial skin temperature associated with unilateral chewing
Authors: BERRY D. C. , YEMM R. 
Published: June 2007

SummaryThe changes in facial skin temperature during prolonged unilateral chewing were investigated by thermography (AGA Thermovision System, Model 665). An increase in skin temperature over the masseter area was demonstrated, but this was not invariable, and not always over the ‘working’ side. The suggestion is made that prolonged bruxism could result in a continuously raised blood flow within the masseter muscle.
An apparatus for the synchronous registration of EMG activity in jaw muscles and of vibrations in the masticatory system
Authors: WIDMALM SVEN‐ERIK , HEDEGÅRD BJÖRN 
Published: June 2007

SummaryThe apparatus described is a combined instrument for simultaneous recording of vibrations and EMG activity. It appears to be a useful means of studying reflex mechanisms in the jaw muscles. It is of especial interest as a method of examining the possible effect of vibrations on different receptors, such as the muscle spindles (Matthews, Hannam & Yemm, 1969).The test results presented have indicated a satisfactory method for recording of vibration frequencies, the paper speed required for distinct registration suitable for measuring purposes, and the necessity of pre‐test calibration. They have given proof of the simultaneous onset of vibration and contact pressure al tooth contact as well as the occurrence of increased pressure after tooth contact indicating continual muscle fibre contraction.
Masticatory function and oral rehabilitation
Authors: BERRY D. C. , POOLE D. F. G. 
Published: June 2007

SummaryExamination of many different animal dentitions suggests that in those whose function is mastication rather than merely prehension, tooth wear is not only normal but essential to achieve full efficiency. A similar character is found in man among Eskimos and Aborigines where these people live on completely natural diets, and also in Anglo‐Saxon skulls. It is suggested that attrition should be a normal process in the human dentition, and compensatory mechanisms for the loss of tooth substance are discussed. The significance of the unworn cusp in relation to dental and other diseases of Western civilisation is considered, together with the suggestion that sufficient evidence now exists to justify simple cusp height reduction as a prophylactic measure.
Some physical properties of dental modelling waxes and of their main constituents
Authors: McCRORIE J. W. 
Published: June 2007

summaryDetails of an X‐ray diffraction study on six dental modelling waxes and on known constituents of modelling waxes are described. The results of thermal expansion, thermal analysis and flow characteristics tests on the materials are given. Application of the knowledge obtained from the investigation is suggested in the formulation of a modelling wax consisting of a binary mixture of paraffin wax and microcrystalline wax.
Induction of apical formation in immature teeth by different endodontic methods of treatment
Authors: VOJINOVIć OLIVERA 
Published: June 2007

summaryAn experimental study is described of the apex formation and structure in immature permanent teeth after vital amputation, vital extirpation and after the treatment of teeth with necrotic pulp. Experiments in young dogs suggest that after vital amputation of the coronal part of the pulp, root formation was continued through the process of changed odontogenesis. In cases where the pulp had been completely extirpated or after the treatment of pulpless teeth, the process of normal odontogenesis was interrupted and the apex was completely closed by non‐homogeneous vital calcified tissue. On the basis of studies of the structure of this calcified tissue, it was concluded that it was a product of the formative activity of cells originating from the successive differentiation of fibroblasts in the young granulation tissue. The experiments suggest that following vital amputation of the pulp in children, further root odontogenesis is possible. In the treatment of pulpless teeth, the basic target should be stimulation and preservation of the formative activity of the granulation tissue cells in the apical part of the root canal to allow the possibility of calcified callus forming in the wide apical opening.
Some biological considerations in crown and bridge prosthetics
Authors: DAHL BJØRN L. 
Published: June 2007

SummaryA review is presented of the literature dealing with the biological compatibility of some materials commonly used in crown and bridge prosthetics. The survey covers materials used for temporary and permanent crowns and for temporary and permanent cementation. When available the results of in vitro toxicity tests and implantation studies have been discussed. The tolerance of the oral mucous membranes to some of the materials has also been considered. However, emphasis has been placed on reports dealing with a possible pulp reaction caused by the materials.
Biological tests of a temporary crown and bridge material
Authors: DAHL BJØRN L. , TRONSTAD LEIF , SPÅGBERG LARZ 
Published: June 2007

SummaryThe biological compatibility of an ethylene imine derivative (Scutan) and a self‐curing methyl methacrylate resin (Sevriton) was assessed in in vitro (cell culture) and in vivo (monkey teeth) tests. In vitro, both materials were toxic when freshly prepared, but Scutan less than Sevriton. Set specimens of both materials were non‐toxic in the experiments with 4 h cell‐material contact. In the 24 h experiments, however, Sevriton had a toxic effect. In vivo experiments confirmed that Sevriton may cause reactions in the pulp which makes it unsuitable for use in direct contact with vital dentine. The pulp reaction caused by Scutan, however, was of a mild nature. It was concluded, therefore, that Scutan may safely be used to make temporary crowns and bridges according to a direct technique.
The use of spectrograms for speech analysis in full denture wearers
Authors: PETROVIĆ ANA 
Published: June 2007

SummarySome aspects of the physiology of speech are discussed, particularly the correlation between the quality of speech and denture morphology.It is suggested that an objective method for the evaluation of speech is the use of spectrographic analysis with computer evaluation. The application of this approach to artificial denture wearers is demonstrated.
Marginal adaptation of composite resins
Authors: AL‐HAMADANI K. K. , CRABB H. S. M. 
Published: June 2007

SummaryThe historical development and important properties of composite resins are briefly reviewed. Experimental work has been undertaken to examine the marginal adaptation of three commercially available composite resins in 100 Class II and Class V restorations; dye penetration tests were used and the measurement of the gap at the tooth/ restoration interface as recorded in photographs obtained by scanning electron microscopy of replicas. In Class V restorations showing marginal leakage by dye penetration the gap at the tooth/restoration interface was in all cases greater cervically than occlusally. The results underline the uncertainty of obtaining a good marginal seal with composite resins both peripherally and along internal line angles.
An alternative treatment in cases with advanced localized attrition
Authors: DAHL BJøRN L. , KROGSTAD OLAF , KARLSEN KJELL 
Published: June 2007

SummaryA combined orthodontic/prosthetic treatment of patients with advanced localized attrition has been described. In one patient the effect of the orthodontic treatment upon the morphological face height has been studied using an X‐ray cephalographic technique and the results have been discussed.
Biological tests of a silicophosphate cement
Authors: DAHL BJøRN L. , TRONSTAD LEIF , SPÅARNBERG LARZ 
Published: June 2007

SummaryThe biological compatibility of a silicophosphale cement (Fluoro‐Thin®) and a zinc phosphate cement (de Trey's Improved®) has been assessed in in vitro (cell culture) and in vivo (monkey teeth) tests. In the in vitro tests both materials were toxic when freshly prepared, In experiments with prolonged cell‐material contact time, with set specimens of the materials, the zinc phosphate cement appeared to be non‐toxic, whereas the silicophosphate cement was clearly toxic. The in vivo experiments confirmed that a possible pulp reaction caused by zinc phosphate cement is of a mild nature. The silicophosphate cement, however, caused a moderate or severe reaction in the pulp after 8 days of observation, and there was chronic inflammation in most teeth after 36 or 72 days. It was concluded, therefore, that Fluoro‐Thin should not be used as a luting agent or for restorative purposes in direct contact with vital dentine.
Reflex control of the jaw muscles by stimuli from receptors in the periodontal membrane
Authors: KLOPROGGE M. J. G. M. 
Published: June 2007

SummaryIn the opinion of a number of investigators, the only function of the mechano‐receptors in the periodontal membrane is to inhibit closure of the jaws via a reflex pathway when a predetermined pressure on the teeth has been exceeded. In our opinion, the receptor system in the periodontal membrane may also play a role in a complex regulatory system which controls the movements of the lower jaw during chewing. In order to test this hypothesis a study was made of the changes occurring in the contraction pattern of three masticatory muscles of the cat, when the cuspids in the upper jaw were displaced in various directions.In all the experimental animals used, electromyographic changes in the three muscles investigated, could be recorded as a result of displacement of the cuspids. The results obtained suggest, at least in the case of the temporal and pterygoid muscles, that there are specific reflexogenic zones in the periodontal membrane. These results support the previously suggested hypothesis that a number of the pressure‐sensitive receptors in the periodontal membrane play a role in a regulatory system which controls the movements of the lower jaw—as during chewing—by exerting a reflex influence on the degree of contraction of the masticatory muscles.In the discussion this hypothesis is worked out in more detail and the extent to which the results fit the chewing pattern of the cat is examined. In the conclusion, the author asks whether the finding of a regulatory system in the cat may also be applied to man.
Masticatory function—a review of the literature
Authors: BATES J. F. , STAFFORD G. D. , HARRISON A. 
Published: June 2007

SummaryRecently, the authors realized that an evaluation of the literature on mastication had never been undertaken, and it is hoped that this review presented in three parts, will be of value, not only to the dental clinician, but to other scientists working in associated fields.The first paper discusses the form of the masticatory cycle in the natural and artificial dentitions, including the controversial question of whether tooth contact occurs during function.The second paper reviews the literature concerning the speed of movement of the mandible, rate of chewing, and the forces developed in chewing.The final paper describes masticatory efficiency and performance, the effect of food on masticatory function, and incorporates a summary of all these three papers.
Oral ability to recognize forms and oral muscular coordination ability in dentulous young and elderly adults*
Authors: LANDT HORST , FRANSSON BO 
Published: June 2007

SummaryA study has been carried out to investigate possible differences between a group of dentulous young adults (average 22.5 years of age) and a group of dentulous elderly individuals (65.9 years), when attempting to recognize forms orally and to carry out tasks which demand a fine‐coordination of the oral muscular apparatus.The results showed, that the older group had reduced ability for both forms of tests used in this study (RF‐test for estimating the oral ability to recognize forms, and MA‐test to estimate oral muscular ability).The reduced capacity of the older individuals to learn the requirements of the tests as compared with the younger ones, was especially obvious. Furthermore, individual differences in this respect were more obvious for the older than for the younger examinees.The suggestion is made that in further studies the number of trial‐rounds may be reduced from three to two. certainly for older individuals and for both the RF‐ and the MA‐test.Because of the obvious correlation between the results of the RF‐ and the MA‐test among older individuals, it is concluded that both forms of tests may measure common or closely related factors, which are reflected by these tests.
Screening in a dental clinic for adult rheumatoid arthritis involving the temporomandibular joint using a statistical discriminant function
Authors: ANDERSON J. A. , BLAIR G. S. 
Published: June 2007

SummaryThe radiological features seen on the temporomandibular joint radiographs of ninety‐nine cases of adult rheumatoid arthritis were used to distinguish this group from a group of eighty‐three control subjects using the method of logistic discrimination. A readily calculable diagnostic score, whose value was verified by a second study involving thirty‐two patients, sixteen of whom suffered from adult rheumatoid arthritis, was estimated. This second study was further used to illustrate how this scoring system would be modified to take account of extra information. Although a long term evaluation of the method is envisaged its clinical application is indicated and its practical value demonstrated.
A method of determining the tensile bond strength of fissure sealant materials
Authors: LOW T. , DAVIES E. H. , VON FRAUNHOFER J. A. 
Published: June 2007

SummaryA simple and reliable method for the determination of the tensile bond strength of sealant materials to enamel is described. Using this method, the tensile bond strength of Nuva Seal to enamel after 7 days in water at 37°C was found to be 36·6±9·0 kg/cm2 with a coefficient of variation of 24·5%. This method would be useful for screening of new and modified sealant materials and the evaluation of new application procedures to ensure an adequate tensile bond strength for clinical use. A tensile bond strength in the range 26–36 kg/cm2 could be used as the base line value for comparison of new materials and procedures involving fissure sealants.
Biological tests of an experimental glass ionomer (silicopolyacrylate) cement
Authors: DAHL BJøRN L. , TRONSTAD LEIF 
Published: June 2007

SummaryThe biological compatibility of an experimental glass ionomer (silicopolyacrylate) cement has been assessed inin vitro (cell culture) and in vivo (monkey teeth) tests. For comparison a conventional silicate cement (Super Syntrex®) was included in the in vivo experiments. In vitro, the glass ionomer cement was toxic when freshly prepared. The toxicity decreased, however, with increasing setting time. In experiments with prolonged cell‐material contact time with specimens which had set for 24 h, the material appeared to be non‐toxic. The in vivo experiments confirmed previous reports concerning unfavourable pulp reactions caused by silicate cement, while the glass ionomer cement caused mainly a mild pulp reaction after 8 days of observation. Unfortunately no longer‐term observations were obtained since the material had been washed out of the cavities within 36 days.
The interdental brush and its place in operative and crown and bridge dentistry
Authors: WÆRHAUG JENS 
Published: June 2007

SummaryThe effect of the interdental brush was evaluated on sixty‐seven extracted teeth which were stained and examined under the stereomicroscope. Thirty‐one of the teeth were totally covered with plaque when the interdental brush was used on them immediately before extraction. Thirty‐six of the teeth were from patients who had used the interdental brush routinely for several years. The interdental brush was found to have an excellent effect both in the central part of the interdental space and on the embrasures. However, the most noteworthy finding was that it removes plaque as far as 2‐2½ mm below the gingival margin. This means that restorations can be kept free of plaque, even if they are extended into the pocket. In modern dentistry ‘extension for prevention of dental caries’ has become a controversial principle because subgingival restorations retain plaque which induces destructive periodontal disease. In many cases this problem can be solved by introducing the interdental brush.
Soft lining to relieve soreness beneath dentures
Authors: MÄKILÄ EINO 
Published: June 2007

SummaryThe mandibular dentures of eighteen patients who suffered from chronic tissue soreness beneath the denture which could not be relieved by bringing the denture into a functionally faultless condition, were furnished with a soft lining. Of the patients re‐examined after 2 weeks, 89% were symptom‐free. After 6 months, 1, 2 and 3 years the percentages of the symptom‐free patients were 64, 79, 60 and 71% of the total re‐examined. However, after soft lining, some relief of the complaint was reported by all patients of the series.The series included a woman with bronchial asthma whose oral mucosa again became sore after she had worn the denture with soft lining for a year, and a bruxist who had a definite relief.The percentage incidence of denture stomatitis increased in the course of the 3‐year period studied. At the listed dates of re‐examination, it was 25, 46, 43, 80 and 100%, respectively.
Physical properties of a nickel‐base alloy prepared by isostatic pressing and sintering of the powdered metal*
Authors: FUYS R. A. , CRAIG R. G. , ASGAR K. 
Published: June 2007

SummaryThe physical and mechanical properties of samples of a nickel‐base alloy fabricated by powder metallurgy were determined. The particle sizes of the powders used to make the samples varied from –80/+ 200 mesh to –325 mesh. The compaction pressure varied from 138 to 414 MN/m2 and the sintering temperature varied from 1150 to 1250°C. The shrinkage during processing, the porosity, tensile strength, yield strength, elongation, and elastic modulus were used to characterize the samples. The strength of the samples generally increased with decreasing particle size of the powder and increasing compaction pressure and sintering temperatures. The porosity and strength, therefore, could be varied over a wide range by controlling the various parameters. The properties of the samples prepared by powder metallurgy were compared with those of the cast alloy and compact bone. Conditions can be selected that will yield equivalent or better properties by powder metallurgy than by casting.
Etching of enamel prior to application of fissure sealants
Authors: WILLIAMS B. , VON FRAUNHOFER J. A. , WINTER G. B. 
Published: June 2007

SummaryAcid etching has been shown to be necessary to increase the bond strength of the polymeric fissure sealants Epoxylite 9075 and Nuva Seal to enamel. For Nuva Seal or Epoxylite 9075 it would appear that it does not matter which concentration between the concentration levels of 30 and 70% is used.