Critical assessment of particle size analysis of porous silica microbead high-performance liquid chromatographic packings by photosedimentation

1979

Abstract Particle size analysis of commercial spherical silica packings of graduated pore size by means of photosedimentation (PS) is critically examined and compared to results obtained by microscopy. To avoid particle fractionation, the suspension prepared for PS measurements should be subjected to gentle ultrasonic treatment. For computing the particle size distribution, the effective density of solvent-filled porous particles has to be inserted into the Stokes equation. Reproducibility of d p , estimated by PS is found to be largely dependent upon the accuracy of the specific pore volume determination. Satisfactory agreement of data between PS and microscopy is obtained for all products…

Reduction of rating scale data by means of signal detection theory

1979

A d’-index computed from ratings of psychological stimuli does not necessarily represent the unbiased psychological distance between these stimuli. Such ratings may not be considered as discrimination tasks in the signal detection sense, because the rater has to discriminate between the psychological impact of the stimuli on some internal continuum rather than between the stimuli as such. The rater therefore can use stimulus-specific criteria for his decisions. As a result, the d’-index computed from the rating data will be biased.

Mechanismus der Umsetzung von 1,1-Diphenylhydrazin mit Azodicarbonsäure-diethylester

1979

Bei der Umsetzung von 1,1-Diphenylhydrazin (1a) mit Azodicarbonsaure-diethylester (2a) uber-lagern sich funf Reaktionsmechanismen: A und B) Oxidation des Diphenylhydrazins 1a durch den Azodicarbonsaureester 2a zum Aminonitren 8; Bildung des Tetrazens 10 entweder durch Dimerisierung von 8 oder uber das Tetrazan 11; Zerfall von 11 in N2 und Diphenylamin. — C) Addition des Aminonitrens 8 an den Azodicarbonsaureester 2a zum Aminoazimin 3a; Zerfall von 3a in das Urethan 4a und den Azidoameisensaureester 5a. — D) Isomerisierung des Aminoazimins 3a zu 13 und Reduktion von 13 durch 1a zum Tetrazen 14; Spaltung von 14 in Diphenylamin und das Azid 15; Zerfall von 15 in Ethylcyanat (17) und den Kohlen…

Analyse de la scolarité et des transports scolaires

1979

Disponible sur : https://iredu.u-bourgogne.fr/wp-content/uploads/2010/03/Cahier31.pdf; International audience; Ce papier sera consacré à l'analyse de deux postes de dépenses particuliers, à savoir ceux relatifs à la scolarité et aux transports scolaires, la présentation jointe de ces deux types de dépenses étant justifiée par le fait que les facteurs spatiaux et de carte scolaire y jouent pour chacun d'eux un rôle explicatif important. Outre les aspects monétaires de ce problème, quelques mesures des coûts de transport évalués directement en unités de temps seront proposées.

Error analysis for a special X-spline

1979

Clenshaw and Negus [1] defined the cubic X-spline, and they applied it to an interpolation problem. In the present paper, for the same interpolation problem, an interpolating splinew is considered by combining two specialX-splines. The construction ofw is such that the computational labour for its determination, in the case of piecewise equally spaced knots, is less than that of the conventional cubic splines c . A complete error analysis ofw is done. One of the main results is that, in the case of piecewise equally spaced knots,w ands c have essentially the same error estimates.

Metabolites of diethylstilboestrol induce sister chromatid exchange in human cultured fibroblasts

1979

Diethylstilboesterol (DES) is one of the few substances for which a clear association with carcinogenicity has been established in man. Nevertheless, it is still widely used, mainly as a cheap oestrogen to increase the slaughter weight of beef, but in spite of this it is not known if residues in the meat or metabolites excreted by the cattle are hazardous to man. It is also unknown whether there is a threshold dose below which DES is harmless. A threshold might be expected if a hormonal mechanism of carcinogensis rather than metabolic activation to an electrophically reactive species operats. This possibility was supported by the observations that DES, in contrast to most other carcinogens,…

Study on the transient characteristic in the human visual system using masking experiments

1979

In this paper the visual masking effect is interpreted on the basic of the transient characteristic in two dimensional neuronal networks. The study investigates the suitability of the effect for use as a measurement method. It is shown that the stimulus distribution in space can be scanned at different points in time and that various dynamic characteristic values of the system can be measured.

Transient hypothyroidism associated with prematurity, sepsis, and respiratory distress.

1979

Serial TSH and T4 determinations were performed in sixty neonates admitted to our hospital for neonatal intensive care within a period of three months. Seven patients (12%) showed transient hypothyroidism on the basis of low T4 and high TSH values. Only one of these patients, who had meconium aspiration and pneumonia, did not have the respiratory distress syndrome. In addition, 4 of these patients had sepsis. All of the patients were born before 37 gestational weeks and had birth weights under 2200 g. In addition, two patients of this gestational age and birth weight group had a progressive fall of T4 to extremely hypothyroid values without simultaneous elevation of TSH. Two of the 5 patien…

Metall-π-Komplexe von Benzolderivaten, XII Hyperfeinstruktur und Linienbreiten in den ESR-Spektren methylierter und deuterierter Bis(η-benzol)chrom(I…

1979

Die vollstandige Reihe der Methyl-Substitutionsprodukte des Bis(η-benzol)chrom(I)+·-Radikalkations sowie ausgewahlte deuterierte Derivate desselben wurden in Losung und in glasartig erstarrtem Medium ESR-spektroskopisch untersucht. 1H-, 2D- und 53Cr-Hyperfeinparameter werden mitgeteilt und das Proton/Deuteron-Kopplungskonstantenverhaltnis wird diskutiert. Die Betrage von a(1HAren) und a(1HMethyl) variieren innerhalb enger Grenzen (3,454,15 bzw. 0,50,7 G), wobei a(1HAren) mit zunehmendem Methylierungsgrad zunimmt. Um die Konformationsabhangigkeit von a(1HMethyl) zu studieren, werden die ESR-Spektren von (η12-[2.2]Paracyclophan)-chrom(I)+·, 21+·, und Bis(1,4-dimethyl-η6-benzol)chrom(I)+·, 5+·…

Observable radizielle Untergruppen von halbeinfachen algebraischen Gruppen

1979

Sei G eine affine algebraische Gruppe, definiert tiber einem algebraisch abgeschlossenen K6rper k von beliebiger Charakteristik. Die observablen Untergruppen von G sind die Untergruppen, die als Stabilisatoren bei rationalen Darstellungen von G auftreten. Sie wurden in [2] und [5] ausfiihrlich diskutiert. Dabei zeigte sich, dab es im allgemeinen wohl sehr schwierig ist zu entscheiden, ob eine Untergruppe observabel ist. Daher ist es sinnvoll, Kriterien zu finden. In [9] gab Sukhanov ftir Charakteristik 0 ein notwendiges und hinreichendes Kriterium daftir an, dab eine radizielle Untergruppe einer halbeinfachen algebraischen Gruppe observabel ist; dabei will ich unter einer radiziellen Unterg…

Radioimmunological determination of somatomedin B in healthy children and patients with HGH deficiency

1979

In 192 boys and girls, aging from 1 month to 16 years, serum somatomedin B levels were performed by radioimmunoassay of Kabi Inc., slightly modified. In girls the mean value increased from the 1 st. month at the end of the second year of live from 10.5±6.2 to 19.2±9.2 mg/1, in boys at the same time from 10±3.9 to 20.3±6.2 mg/1. The values decreased in girls in the following years up to the age of 14-16 years to 13.7±7.5 mg/1; in the boys to 11.5±4.2mg/1. The beginning of the decrease was in girls two years earlier than in boys. To these values of normal children were compared the values of 8 patients with HGH deficiency. The mean of these cildren was 4.2 mg/1, significantly below the values…

Physiologie der Photosynthese Höherer Pflanzen Die Anpassung an die Lichtbedingungen

1979

B�schels�tze zur Charakterisierung projektiv darstellbarer Zykelebenen

1979

Renales Kallikrein-Kinin-System und Blutdruckregulation

1979

Das mit dem Urin ausgeschiedene Kallikrein scheint in der Niere gebildet zu werden. Hauptbildungsort von Kallikrein in der Niere ist das distale Tubulussystem vom juxtaglomerularen Apparat bis zu den Sammelrohren. Die Infusion von Kininen in die Nierenarterie fuhrt zu einer Zunahme des renalen Blutflusses sowie zur Diurese und Natriurese, wobei ein Teil der Wirkung der Kinine offenbar durch Prostaglandine vermittelt wird. Bisher ist jedoch nicht klar, welche physiologische Wirkung dem Kallikrein-Kinin-System fur die Natrium- und Volumenhomoostase bzw. fur die Blutdruckregulation zukommt. Die Bildung und Ausscheidung von Kallikrein wird durch Mineralocorticoide gesteigert und durch Spironola…

Computer-Aided Simultaneous Determination of Noise and Gain Parameters of Microwave Transistors

1979

A new method for the determination of noise and gain parameters of microwave linear two-ports (transistors) is presented. The method allows the simultaneous determination of the two parameter sets through a proper computer-aided procedure which processes the experimental data obtained from a measuring system employing noise meters and generators only. Experimental verifications carried-out on a microwave low noise transistor in S-band are reported.

false

1979

Photoemission of spin-polarized electrons from negative electron affinity GaAsP

1979

GaAs0.62P0.38 activated to negative electron affinity and irradiated with circularly polarized light of a wavelength shorter than approximately 680 nm emits electrons whose spins are mainly oriented antiparallel to the photon spins. At 650 nm a degree of electron spin polarization around 40% is observed. The spectrum of spin polarization of the photoelectrons is similar to that known from GaAs cathodes but is shifted to shorter wavelengths. 25 μA current of spin-polarized electrons were achieved with a 5 mW He-Ne laser.

Positron trapping rate into vacancy clusters

1979

The trapping rate of positrons into vacancy clusters in metals has been calculated. It increases with the trap size and binding energy and approximately scales with the number of vacancies in small clusters. The phonon-mediated contribution to the trapping rate is small. The temperature dependence of the trapping process is discussed.

false

1979

Activité catalytique de dérivés du ruthénium(II) contenant le ligand triméthylyphosphine

1979

Abstract Three ruthenium(II) complexes containing the ligand PMe3,:RuCl2(PMe3)(C6H6) (I), RuCl2(PMe3)4 (II) and RuCl2(CO)2(PMe3)2 (III) were prepared and their catalytic properties investigated. They showed activity as hydrogenation catalysts in the presence of Me2NH · BH3 and alcohol and the activity increased significantly in the order I

Morphological and biochemical changes in striated muscle after experimental tourniquet ischaemia.

1979

Histological and biochemical changes were studied in the striated muscle following total tourniquet ischaemia between one and four h, the reflow time being 30 min and 24 h. Electronmicroscopy was applied to study the fine structure of the muscle after 24 h reflow. In light microscopy ischaemic changes were not seen even when the tourniquet time was extended to four h. When a four-h ischaemia was followed by a 24-h recovery period, the electron microscopy showed a variety of minor mitochondrial changes such as condensed and slightly dilatated mitochondria. The SDH activities did not vary significantly between the experimental and control samples even after a four-h ischaemia followed by 30 m…

Properties of condensed spin-aligned atomic hydrogen from variational calculations

1979

The optimal Jastrow-type ground-state wave function of spin-aligned atomic hydrogen is calculated using the pair potential of Kolos and Wolniewicz. The optimization is performed by solving the Euler equation in the hypernetted chain approximation. Accurate energies as well as pair-distribution functions are obtained. The Bose-Einstein condensate fraction is evaluated from the one-particle momentum distribution. The pair distribution function is also used to obtain stability criteria for the system and minimal values for the aligning magnetic field are calculated at low densities. The resulting values of the minimal aligning fields are considerably higher than those obtained previously.

false

1979

The thermal degradation behavior of head-to-head (H-H) and head-to-tail (H-T) polystyrenes and poly(vinylcyclohexane)s has been investigated by direct pyrolysis in a mass spectrometer. Both H-H and H-T isomers show only small differences in their initial temperatures of decomposition but remarkably different degradation processes. Whereas H-T polystyrene decomposes in accordance with earlier investigations mainly by a radicalic depolymerization into the monomer and yields only a small amount of dimer and trimer, the H-H polystyrene shows no unzipping and only a statistic degradation into oligomeric styrenes. The formation of stilbene is a diagnostic reaction of H-H polystyrene. The pyrolysi…

Measurement of residual stresses by the hole-drilling method: Influence of hole eccentricity

1979

The hole-drilling method is a semidestructive technique which allows the measurement of residual stresses. In this method, a source of error is due to the misalignment between the hole and rosette centres. This paper presents a theoretical analysis of the influence of such misalignment on the strains measured by the rosette. Formulae which give the residual stresses taking account of the hole eccentricity are derived. Finally, the errors, which affect the residual stresses when the eccentricity is neglected, are evaluated for some commercial strain-gauge rosettes especially developed for the hole-drilling method.

Effect of cooling rate on the viscoelastic properties in the plastic zone of solid polymers

1979

PMMA and PC samples were subjected to several cooling rates from the glass transition temperature.

Morphometry of myocardial apex in endurance-trained mice of different ages

1979

Mitochondrial volume density, surface density of the outer mitochondrial membrane, the mean number and size of mitochondria, and the mean surface density of crista membranes together with the volume densities of myofibrils and sarcoplasmic space were morpho-metrically analyzed in cardiac muscle of two groups of sedentary control mice aged 3 and 7 months, and in two groups of mice trained either 1 month rather intensely or 4 months moderately. Of the calculated mitochondrial variables only the surface density of the outer mitochondrial membrane differed between the older controls and the older trained animals, the density being slightly smaller in the trained group. The myofibrillar volume d…

Collective subspaces for large amplitude motion and the generator coordinate method

1979

The collection path $|\ensuremath{\varphi}(q)〉$ to be used in a microscopic description of large amplitude collective motion is determined by means of the generator coordinate method. By varying the total energy with respect to $|\ensuremath{\varphi}(q)〉$ and performing an adiabatic expansion a hierarchy of equations is obtained which determines uniquely a hierarchy of collective paths with increasing complexity. To zeroth order the $|\ensuremath{\varphi}(q)〉$ are Slater determinants, to first order they include 2p-2h correlations. In both cases simple noninterative prescriptions for an explicit construction of the path are derived. For a correlated path their solutions agree at the Hartree…

Quantitative analysis of vitamin K1 and vitamin K1 2,3-epoxide in plasma by electron-capture gas-liquid chromatography.

1979

Discovery of an epidermoid of the skull concomitant with a homolateral subacute traumatic subdural hematoma

1979

The case of a man of 32 years with an epidermoid of the left side of the skull is reported. The tumor itself was asymptomatic and was discovered accidentally because of a subdural hematoma on the same side. After a closed head injury, this patient had symptoms of an intracranial space occupying lesion (hematoma) on the left after a symptom-free interval. The left carotid angiogram demonstrated the characteristic picture of a subdural hematoma in the left parieto-temporo-occipital region. At the same time, characteristic changes in the skull on the same side, which were more apparent after removal of the hematoma, suggested an epidermal tumour of the skull. This was verified at operation.

Konformation sterisch gehinderter Anilin-Kationradikale und Benzyl-Kationen/On the Conformation of Sterically Hindered Aniline Cation Radicals and Be…

1979

Abstract A series of aniline cation radicals have been generated in a flow apparatus, and their ESR spectra have been recorded and interpreted. The data show that the NR1R2 substituents are less twisted in these systems than the CR1R2 substituents in the isoelectronic but sterically less hindered benzyl radicals, in accordance with MNDO calculations. The conformations of these systems are strongly influenced by electronic π-resonance effects which limit the usefulness of steric models for structural predictions. The results suggest that the CR1R2 substituent in the benzyl cations is less twisted than in the corresponding radicals. An ESR measurement of these radicals should therefore provid…

The Design of an Infrastructure for Technology Transfer in Southern Italy - Role of Regional Institutions

1979

Abstract This paper coordinates and integrates the interventions of Proff. G. LO GIUDICE and A. ROMANO, included in the conference programme. It starts mainly from the socio-economical system of Southern Italy, and it consists in the following main points: - analysis of the system features to be interconnected for the development of an infrastructure for developing technological transfer; - ways of understanding the suitability of technologies for Southern Italy; - a proposal for a macro-organizational model for the development of an infrastructure aiming at the technological transfer; - pointing out the role of the”Regioni” and of the direct Government interventions in the innovative proce…

EMG frequency spectrum, muscle structure, and fatigue during dynamic contractions in man

1979

Fatigue of the vastus lateralis muscle was studied in healthy well-conditioned students, who differed considerable regarding their muscle fibre type distribution. Muscle force decline during repeated maximum voluntary knee extensions at a constant angular velocity (180 degree X s-1 or rad X s-1), using isokinetic equipment, was taken as the criterion for the degree of fatigue. In an attempt to study quantitative as well as qualitative changes in the EMG pattern, integrated EMG (IEMG) and the frequency of the mean power (MPF), computed from the power spectral density function (PSDF), were analysed. It was found that individuals with muscles made up of a high proportion of fast twitch (FT) mu…

Patterns of wall synthesis inSaccharomyces cerevisiae

1979

Wall formation inSaccharomyces cerevisiae seems to be the result of two main patterns of wall material deposition: (i) around the whole periphery of the cell in nonbudding ones, and (ii) mainly at the tip of the daughter cell or at the cross wall that separates dividing cells. This interpretation has been obtained following experiments in which RNA or protein synthesis has been inhibited. Under these conditions, glucan formation takes place, and wall thickening is probably due to the accumulation of this polysaccharide. Furthermore, once a pattern of wall deposition has been established, it is not modified by inhibition of RNA or protein synthesis.

The compound internal pyrenoid in cultured cells of the green algaMonoraphidium griffithii (Berkel.) Komar.-Legner.

1979

The chloroplast ultrastructure ofMonoraphidium griffithii (Berkel.) Komar.-Legner. has been studied in axenic cultures of various ages. The algae have grown in a complete nutrient solution (illumination about 3,000 lx) and on its agar medium (illumination about 600 lx). The large parietal cup-shaped chloroplast of the cells includes a multiformed compound internal pyrenoid that is situated, especially in older cells, in the central part of the chloroplast opposite to the dictyosome and the nucleus. The chloroplast thylakoids either reach the edge of the pyrenoid or penetrate its matrix and run there parallel in more or less long bits. Starch grains were not found to form any sheath around t…

Beitrag zum Divisionsproblem for Ultradistributionen und ein Fortsetzungssatz

1979

In this note we give a characterization of ultradistributions, which are supported by a single point. As a consequence we get a necessary condition for the solvability of the division problem for ultradistributions similar to the well-known condition in the case of distributions (cf. Malgrange [12]). Finally an extension theorem for ultradistributions is proved, using exponential growth conditions, that generalize the condition of Lojasiewicz [11].

Production ofWbosons in proton-nucleus collisions

1979

It is shown that nuclear effects can cause an enhancement in the cross section for production of $W$ bosons in a proton-nucleus collision. The cross section near threshold is a few orders of magnitude higher than expected from a linear dependence on the atomic number. Encouraging implications for experiments with fixed targets at laboratory energies of ${10}^{3}$ GeV and higher are discussed. We also discuss lepton-pair production off nuclei.