Stress relaxation of a polyisobutylene under large strains

1980

Stress relaxation data after single and double elongational strain “steps” were collected on a commercial polyisobutylene, Oppanol B 50. Analogously to other cases a separability of deformation and time effects was observed over an extended time region for the relaxation after single “steps”. Moreover, by comparing the results after double with those after single steps, it was noted that any rheological equation of integral type having a rigorously constant memory function is not able to describe accurately the full body of results presented here. On the other hand the data were favorably compared with the predictions of a model proposed earlier.

Bedeutung von Assoziationsphänomenen quartärer Oniumverbindungen in der organischen Phase für den Ablauf phasentransferktalysierter Reaktionen

1980

Quartare Oniumsalze sind, wie dampfdruckosmometrische Messungen zeigen, in Benzol und Chloroform assoziiert [in Benzol starker (Faktor 4–15) als in Chloroform (Faktor 1.2 – 2.4)]. Im Homogen- und Zweiphasensystem laufen die Modellreaktionen (1) und (2) mit steigendem Assoziationsgrad schneller ab — langsamer im Zweiphasensystem wegen des Wassergehaltes der organischen Phase (Verminderung des Assoziationsgrades). Assoziationsphanomene sind offensichtlich fur die “Katalyse” im Zweiphasensystem wesentlich. Importance of Association Phenomena of Quaternary Onium Salts in the Organic Phase Responsible for the Course of Phase-Transfer-Catalysed Reactions As shown by vapour pressure osmometry quat…

Adiabatic Time-Dependent Hartree-Fock Calculations of the Optimal Path, the Potential, and the Mass Parameter for Large-Amplitude Collective Motion

1980

The adiabatic time-dependent Hartree-Fock theory is reformulated in order to yield a simple differential equation for the collective path with accompanying simple expressions for the collective mass and the potential. With use of three-dimensional coordinate- and momentum-space techniques and density-dependent interactions, the new adiabatic time-dependent Hartree-Fock formalism is applied to $\ensuremath{\alpha}\ensuremath{-}\ensuremath{\alpha}$ scattering and correspondingly to the fission mode of $^{8}\mathrm{Be}$. In the overlapping region the resulting collective mass deviates strongly from the reduced mass.

Electrophoretic separation of a class of nucleosomes enriched in HMG 14 and 17 and actively transcribed globin genes.

1980

Monomer nucleosomes from chick erythrocytes can be fractionated according to their electrophoretic mobility in (comparatively) high salt acrylamide gels. We show that the fractionation is based predominantly on differences in charge. The monomer heterogeneity persists even when the nucleosomes are trimmed down to 145 bp with Exo III or when H1 and H5 are removed. The slowest migrating monomers are associated with HMG 14 and 17; however, we do not believe that these proteins are entirely responsible for the altered mobility since the nucleosome heterogeneity persists even after removal of HMG 14 and 17. The DNA associated with the HMG 14 and 17 containing nucleosomes is shown to be enriched …

false

1980

false

1980

false

1980

Meson exchange and isobar current effects in nuclear photon scattering

1980

Explicit expressions of meson exchange and isobar current contributions to the nuclear two-photon amplitude are derived in the non-relativistic limit. In connection with this amplitude the requirement of gauge invariance on the photon scattering amplitude and on the nuclear electromagnetic interaction operator is discussed in detail.

Distribution of aquatic Oligochaeta in the Finnish Lake District

1980

SUMMARY. The distribution of oligochaetes was examined at sampling stations grouped into three types: (1), in eutrophic and dystrophic areas or in areas polluted by pulp-mill wastewaters; (2), slightly eutrophic stations; (3), ‘clean’ stations unaffected by sewage or other inputs. Limnodrilus hoffmeisteri and Potamothrix hammoniensis were practically the only species in group 1, and the same species accounted for two thirds of the total numbers in group 2, although Peloscolex ferox and some other species also occurred. At the cleanest stations the dominating species were P. ferox, Psammoryctides barbatus, Stylodrilus heringianus and Tubifex tubifex. A factor analysis showed that L. hoffmeis…

Splineapproximationen von beliebigem Defekt zur numerischen L�sung gew�hnlicher Differentialgleichungen. Teil III

1980

In the first part [5] a general procedure is presented to obtain polynomial spline approximations of arbitrary defect for the solution of the initial value problem of ordinary differential equations. The essential result is a divergence theorem in dependence of the polynomial degree and the defect of the spline functions. In this second part the convergent procedures are investigated and two convergence theorems are proved. Furthermore the question is treated, whether the convergent procedures are appropriate for the numerical solution of stiff equations. The paper is finished by a convergence theorem for a procedure producing spline approximations in a natural way by the discrete approxima…

Sound conversion phenomena at the free surface of liquid helium. I. Calculation of the coefficients of reflection, transmission, and transformation o…

1980

On the basis of a set of boundary conditions describing quite generally mass and energy transport processes across the free surface of helium II, the acoustic coefficients of reflection, transmission, and transformation of first sound, second sound, and the sound wave propagating in the vapor are calculated in the case of perpendicular incidence of sound waves against the liquid-vapor phase boundary. Considering rigorously the influences of the Onsager surface coefficients, the isobaric thermal expansion coefficients, and the thermal conductivities of the liquid and the vapor, we derive sets of equations from which the acoustic coefficients are determined numerically. For estimations, simpl…

An on-line mass separator for fission-produced alkali isotopes

1980

Abstract The design of an on-line mass separator installed at the TRIGA reactor in Mainz is described and its performance discussed. A tungsten oven, filled with about 2 g of 235U embedded in graphite, is exposed to a flux of 1.7 × 1011 thermal neutrons (s− cm−2) near the reactor core. After diffusion out of the graphite the fission-produced alkali isotopes are surface-ionized and electromagnetically mass-separated, the resolving power being about 750. Losses during the diffusion out of the target material are discussed. Due to these losses the maximum separator efficiency is about 5%, corresponding to a source strength of about 109 particles s−1 for the most abundant isotopes. The heaviest…

Beta-delayed particle emission of 36K

1980

Abstract 36 Ar targets of 19 μg cm 2 thickness were made by a sandwich technique in which a 70 nm layer of Al was evaporated onto the implanted Al surface between five successive implantations of 36 Ar ions. The sources of 36 K were prepared by depositing the recoil atoms from the 36 Ar(p, n) 36 K reaction by means of a helium jet onto a fast transport tape. The measured delayed particle spectra revealed 11 proton groups (0.5 MeV E p E α 36 K. Total proton and α-particle branching ratios were measured to be 4.8 × 10 −4 and 3 × 10 −5 , respectively. Partial level widths and reduced proton and α-particle transition widths were determined for several individual levels with the aid of additiona…

Treatment of advanced prostatic cancer with parenteral cyproterone acetate: a phase III randomised trial.

1980

Summary— Forty-two patients with previously untreated T3/4 N1-4 MO/1 prostatic adenocarcinoma were treated with either cyproterone acetate (n=21; 300 mg intramuscularly per week) or oestradiol undecylate (n=21; 100 mg intramuscularly per month) after extensive staging which included open skeletal biopsy and pelvic lymphadenectomy in some cases. Subjective and objective parameters as well as signs of drug toxicity were recorded regularly. Evaluation after 6 months showed cyproterone acetate to be more effective in the following respects: (1) the significantly different castration effect as judged by plasma testosterone, (2) the objective voiding pattern and tumour response, with regression o…

Age-dependent alterations of DNA synthesis. Terminal deoxynucleotidyl transferase and DNA polymerase activities in bone marrow subpopulations from mi…

1980

Abstract The decrease of functional capacity of cellular immunity during ageing seems to be due to cellular changes of stem cells, particularly in the growth properties and the cell density in T-cell subsets. We approached this problem at the molecular biological level by quantifying the key enzymes necessary for DNA synthesis in bone marrow cells from mice: deoxynucleotidyl transferase (TdT) and DNA polymerase α. The bone marrow cells were fractionated on a discontinuous bovine serum albumin density gradient and the extractable enzyme activities (expressed per 10 8 nucleated cells in the respective fraction) were determined. TdT activity was found to decrease markedly during ageing. Mature…

Papaverine decreases the efflux of42K in guinea-pig atrial heart muscle

1980

The effects of papaverine on resting potential and efflux of42K were investigated in guinea-pig left atria. Papaverine significantly reduced the potassium efflux in beating preparations. In resting preparations, the efflux of potassium was only slightly affected. However, the resting potential was significantly reduced by papaverine by about 5 mV.

Interstitielle Nephritis bei atypischer Manifestation eines Sj�gren's Syndrom

1980

A patient was observed with interstitial nephritis which resulted in renal tubular acidosis (distal type), tubular proteinuria and defective urinary concentrating ability in the absence of edema, elevated arterial blood pressure, glomerular proteinuria or abnormal urinary sediment. The presence of interstitial nephritis was established by renal biopsy which showed dense infiltrates in the interstitium, interstitial fibrosis and thickening and splitting of the pericapillary basal membranes. Immunofluorescence was non contributory. Extrarenal symptoms were discrete (arthralgia of both hands, Raynaud's syndrome upon cold exposure). Mixed connective tissue disease (MCTD) was suspected because o…

Crystal field splitting of some rare earth intermetallic compounds with Cu3Au structure

1980

Inelastic neutron scattering studies were performed in the paramagnetic phases of several rare earth compounds that crystallize in the cubic Cu3Au structure: ErPb3, ErTl3, ErIn3, HoPb3, HoTl3, HoIn3, PrSn3, PrPb3, PrTl3, PrIn3, CeIn3, La1−c Pr c Tl3, and Pr(In0.5Tl0.5)3. The energies, widths and intensities of the crystal field excitations are determined and discussed in terms of interactions between the rare earth ions. Variations of the crystal field parameters are observed across the series.

Not Race, but Grace: Presbyterian Missionaries and American Indians, 1837-1893

1980

Race, writes George W. Stocking, Jr., was "a characteristically nineteenthcentury phenomenon." Historians of articulate racial thought in America generally believe that the optimism of the eighteenth century gave way in the nineteenth to pessimism in matters of race. Growing numbers of scientists, and perhaps nonscientists too, came to believe that certain races were innately inferior, retarded by inherited qualities that were unchangeable or changeable only over long periods of time, and that cultural manifestations were the product primarily of biological endowment. By late in the century, according to Stocking, "race and culture were linked in a single evolutionary hierarchy extending fr…

LaAg x In1?x

1980

The phonon dispersion of LaAg x In1−x (x=1, 0.89, 0.8) has been studied by inelastic neutron scattering in the cubic high temperature phase. A soft mode behaviour was observed at theM-point. The doubling and the cubic to tetragonal deformation of the elementary cell was observed through the phase transition. The measurements of the elastic constants were extended to 450 K and their magnetic field dependence was investigated.

Evolution of brain abscess in cats formation of capsule and resolution of brain edema

1980

Brain abscess evolution was studied in an experimental model in the cat correlating the computed tomographic scan appearance with intracranial pressure, brain edema and histopathological findings. Brain inflammation was produced by direct inoculation of Staphylococcus aureus into the white matter. Abscesses developed in all animals. The ring enhancement around the necrotic focus seen at an early stage after contrast-medium injection cannot be equated with capsule formation as long as the abscess diameter increased. Parallel to the acute stage of abscess, the intraventricular pressure increased due to the rising mass effect and the spreading edma. The morphological investigations revealed on…

Precise vs General Feedback in Reducing Field-Dependence

1980

Summary.-To investigate the effect of feedback on performance of the Rod-and-frame Test the standard test procedure mas altered. The result of the alteration was a procedure which was called the Rod-and-frame Test as a Learning Task. On this task the subiect has to adjust the rod to the vertical twice in succession from each tilting position, whereby he is permitred a maximum of 10 trials in each tilting position and a range of tolerance of elo. After each trial the subject is given feedback about his performance. An experiment was conducted with 30 male and 30 female students to investigate whether a precise feedback giving both the direction and the degree of the rod's deviation from the …

Silicone-Silver Penile Prosthesis: Description, Operative Approach and Results

1980

A silicone penile prosthesis in which silver wires are embedded to allow for voluntary bending of the penis for urination and resting position and for straightening for intercourse is described. The implantation is done via a hemicircular incision on the dorsum of the penis in the sulcus coronarius. Buck's fascia is identified and opened, and the corpora are dilated up to 30F. After the exact length is determined with a special sizer the prosthesis is slipped into each corpus cavernosum. The advantage of this approach is the optimal insertion of the prosthesis distal to the sulcus coronarius, thereby preventing kinking of the glans during intercourse. Our experiences with the implantation i…

Inelastic neutron scattering by coupled rotational and translational modes in KCN

1980

The TA [100] phonon branch of the molecular crystal KCN was studied by inelastic neutron scattering in the cubic phase. In addition the distribution of the quasielastic scattered neutrons was investigated. The results are analysed by assuming a coupling of the phonon modes to the rotational degrees of freedom of the CN-dumb-bells which are regarded as a system of interacting quadrupoles. A good description of the present results and also of the existing ultrasonic and Brillouin data is achieved by a simple model which uses a single collective rotational mode of finite excitation energy and line width.

On the projectives of a group algebra

1980

Besoins en équipements pour adultes handicapés et inadaptés (VIIIè plan)

1980

Référence interne : 80019

A BASIC MODEL OF INTERACTING SUBJECTS

1980

Abstract In studying the problem of interaction between subjects, an approach which allows us to define in an unambiguous way the concepts of symmetrical, complementary and parallel interaction is proposed. This approach makes use of a point of view within which it is possible to develop a rational model based only on some fundamental elements of set theory and mathematical logic The model allows us to develop a probabilistic theory of change, the representation basis of which is furnished by the 16 basic set functions. The functions represent operations on two partially overlapping sets, which will be called the “worlds”, of interacting subjects.. Both an interaction test that allows a “me…

The neutron binding energy in the neutron-rich nucleus93Sr

1980

The neutron binding energy in93Sr has been determined to (5230±6) keV from energy correspondences between levels defined by γ-ray transitions and β-delayed neutron emission.

Wall motion characteristic of the right pulmonary artery in the suprasternal echocardiogram

1980

This study describes the motion pattern of the right pulmonary artery (RPA) as it can be assessed from the suprasternal echocardiogram. The motion characteristic of the RPA is dependent on hemodynamic factors within the lumen of the RPA and those within the left atrium and the aortic arch. During atrial contraction the superior wall of the left atrium separates from the inferior wall of the RPA (IWRPA) and produces an "a" dip in the wall motion of the IWRPA. During isovolumic contraction the RPA is shifted upward (IC point). The incisura in the pulmonary artery pressure curve reflecting pulmonic valve closure can be seen by a sudden decrease in the diameter of the RPA (PC point). In conditi…

Ermittlung des biomechanischen Schwingungsverhaltens menschlicher Bulbi mit Video-Technik

1980

Mechanische Schwingungen konnen die visuelle Wahrnehmung beeintrachtigen. Das ist vor allem dann zu erwarten, wenn der Glaskorper des Auges in Resonanzschwingungen gerat. Experimente mit 8 Versuchspersonen und je einer Wiederholung dienten der Ermittlung des frequenzabhangigen biomechanischen Ubertragungsverhaltens von mechanischen Schwingungen zwischen Schadel und Bulbus. Die Bewegungen eines Reflexpunktes der angestrahlten Hornhaut und eines Lichtpunktes auf der Stirn wurden von einer Fernsehkamera erfast und uber ein Multipoint-X-Y-Tracker-System mit Direktschreiber registriert. Die Auswertung hat — ahnlich wie bei Tierexperimenten mit anderer Methodik-typische Resonanzkurven der Bulbi m…

Ultrastructural changes of the intercellular relationship in impaired human spermatogenesis

1980

In seven hypo- or aspermic patients, electron microscopic investigations of the intercellular connections of the seminiferous tubule were performed. The analysis of cell junctions of Sertoli cells and germ cells revealed irregularities of the Sertoli-cell junctions, hypoplasias of occluding junctions, hypo- and hyperplasias of the Sertoli-spermatid cell junctions and abnormal formation of Sertoli cell junctions with early spermatids, spermatocytes, and spermatogonia. Gap junction-like cell membrane specializations were very rare. Intercellular cytoplasmic bridges of germ cells were always present together with these cells. One hypoplastic bridge connecting two spermatogonia was found. The r…

Model of partial crystallization and melting derived from small-angle X-ray scattering and electron microscopic studies on low-density polyethylene

1980

A temperature-dependent small-angle x-ray scattering and electron microscopic study on a sample of low-density polyethylene affords a determination of the structure changes in a heating and cooling cycle and suggests a new model of partial crystallization and melting. The analysis of SAXS data is based upon some general properties of the electron-density correlation function. Electron micrographs are obtained from stained sections γ irradiated at elevated temperatures and are analyzed quantitatively by statistical means. According to the model proposed here the thickness distribution in the amorphous layers, rather than that of the crystalline regions, is the essential factor governing the …

Intraductal proliferation in the pancreas and its relationship to human and experimental carcinogenesis

1980

In 21 patients who had undergone total pancreatectomy for pancreatic head carcinoma, the uninvolved pancreas was examined with regard to the type, incidence and regional distribution of duct epithelial proliferation. The results were compared with those in 37 operative specimens from patients with chronic pancreatitis, in 46 normal pancreases from autopsies and with findings in experimental pancreatic carcinogenesis. While the incidence of squamous metaplasia and non-papillary epithelial hypertrophy varied little in the different groups, papillary epithelial hyperplasia was found three times more often in cases of carcinoma, with associated mild duct obstruction. Atypical epithelial prolife…

Direct evaluation of the electron density correlation function of partially crystalline polymers

1980

A discussion of the general properties of the one-dimensional electron density correlation function K(z) of a partially crystalline polymer with lamellar structure shows that application of a graphical extrapolation procedure permits direct determination of the crystallinity, the specific inner surface, and the electron density difference ηc − ηa. The procedure is based upon the occurrence of a straight section in the “self-correlation” range of K(z). Curved and nonparallel lamellae do not invalidate the concept. In the case of heterogeneous samples composed of partially crystalline and totally amorphous regions, some of the parameters of the experimentally obtained correlation function, as…

Zur Analyse von Milchsäure-Glykolsäure-Copolyestern

1980

Fur L-(–)-Lactid-Glykolid-Copolyester (3) wurden drei voneinander unabhangige Analysenmethoden zur Bestimmung der Copolymeren-Zusammensetzung ausgearbeitet. Die 1H-NMR-Spektroskopie wurde fur Copolyester mit Lactid-Gehalten uber 10 Gew.-% erfolgreich angewandt, nachdem mit Trifluoressigsaure ein geeignetes Losungsmittel gefunden war. Insbesondere fur die praktisch interessanten Materialien mit kleinem Lactid-Anteil, wie z. B. resorbierbares chirurgisches Nahtmaterial, eignen sich die Messung der optischen Rotation sowie eine chemische Methode, die auf der quantitativen Bestimmung der Milchsaure nach vorhergehender alkalischer Totalhydrolyse beruht. The copolymer-composition of L-(–)-lactide…

PHOSPHORORGANISCHE VERBINDUNGEN 921

1980

Optisch aktive Phosphinigsaureamide R1R2PNR2 4 (R1 [dbnd] Ph, R2 [dbnd] Me bzw. Et, R [dbnd] Et) sind durch kathodische Spaltung bzw.Cyanolyse optisch aktiver Amidophosphoniumsalze [R1R2R3PNR2]X (R...