Measurements on Melting Pressure,Metastable Solid Phases,and Molar Volume of Univariant Saturated Helium Mixture

A concentration-saturated helium mixture at the melting pressure consists of two liquid phases and one or two solid phases. The equilibrium system is univariant, whose properties depend uniquely on temperature. Four coexisting phases can exist on singular points, which are called quadruple points. As a univariant system, the melting pressure could be used as a thermometric standard. It would provide some advantages compared to the current reference, namely pure $^3$ He, especially at the lowest temperatures below 1 mK. We have extended the melting pressure measurements of the concentration-saturated helium mixture from 10 to 460 mK. The density of the dilute liquid phase was also recorded. The effect of the equilibrium crystal structure changing from hcp to bcc was clearly seen at $T=294$  mK at the melting pressure $P=2.638$  MPa. We observed the existence of metastable solid phases around this point. No evidence was found for the presence of another, disputed, quadruple point at around 400 mK. The experimental results agree well with our previous calculations at low temperatures, but deviate above 200 mK.     

MOTHER: System for continuous capturing of display stream

This paper describes an efficient technique to record display output stream with memory resident software. This kind of recording can be made useful for studying text writing processes experimentally, for example programmers behaviour during coding. The system is inconspicuous in test situation and does not seem to affect the testees working. Separate software has been developed for reviewing captured sessions.     

The effect of delaying autumn incorporation of green manure crop on N mineralization and spring wheat (Triticum aestivum L.) performance

The use of legumes as green manuring crops does involve a potential riskof N leaching losses over the winter period. The susceptibility of cropresidue-derived N to losses and the pre-crop value of a green manuring crop canbe manipulated by proper timing of incorporation into soil. In this study,mineralization of C and N was investigated in a range of low temperatures,including thawing and freezing, that are characteristic to autumn green manureincorporation and its decomposition. The pre-crop effect of green manuring wasfurther tested with spring wheat under field conditions. We hypothesized thatdelaying green manure incorporation in the autumn would reduce the risk of Nlosses from the field and maximize the N transfer to a successive spring wheatcrop. To test the hypothesis, N mineralization was followed in alaboratory experiment where red clover (Trifoliumpratense L.) shoots were incubated at 4–8 °Cfor 40–80 days to simulate early autumn, delayed autumn and late autumnincorporation of a green manuring crop, followed by an incubation at–2 °C or at –2 °C to+4 °C for 25 days to simulate winter conditions. In asimultaneous field experiment, we measured the effect ofdelayed autumn incorporation of common vetch (Vicia sativaL.) green fallow on spring wheat performance. In the laboratoryexperiment, significant N mineralization during incubation wasdetected when simulating both early autumn and delayed autumn incorporation. Incontrast, no net N mineralization was detected when simulating lateincorporation. In the field experiment, the N supply fromsoil to spring wheat was higher in the late and delayed incorporationtreatmentsthan in early or spring incorporation of green manure. Late incorporationalso produced most wheat grain. We conclude that different amounts of N becomeavailable to wheat, depending on the time of incorporation of green manureresidues in soil. This difference is due to temperature. Late or delayedincorporation of green manure residues has the potential to reduce thesusceptibility of mineral N to leaching and yields more N available to asubsequent crop.     

Experiments on nonlinear acoustics in3He-B

Observations and applications of nonlinear acoustic phenomena in superfluid³He-B are reported. Two-phonon absorption (TPA) by the real squashing (rsq) mode has been detected under several experimental conditions below p = 3.5 bar, using two coincident sound pulses. The attenuation peak height has been investigated as a function of the energy densities of the two sound waves. We discovered the five-fold Zeeman splitting of TPA by parallel sound pulses in an applied magnetic field and the two-fold dispersion splitting due to the finite wave vector of the mode when the two sound pulses are mutually perpendicular. The dispersion relation of the real squashing mode has been investigated at zero pressure and in zero magnetic field by exciting the mode with two parallel, perpendicular, or antiparallel sound waves. Experimental values for the parameters that determine the collective-mode velocities have been extracted from the positions of the observed attenuation maxima. An anomalous structure has been observed in the attenuation and phase velocity spectra of a single high-intensity sound wave near the threshold for pair breaking by two phonons; in an applied magnetic field the phase velocity anomaly splits into a triplet.     

Potentiometrische Titration des Gesamts?uregehaltes von Weinen und Lik?ren

Zusammenfassung Es wird eine potentiometrische Methode für die Bestimmung des Gesamtsäuregehaltes der Weine und Liköre beschrieben und auf Grund experimenteller Versuche der Einfluß verschiedener Faktoren auf die Resultate diskutiért.     

Symptoms and signs and their prognostic value in tracheal carcinoma

Of all the 95 primary tracheal carcinomas diagnosed in Finland in 1967-1985, 72% were squamous cell carcinomas. Fifty-three percent were located in the lower third of the trachea. main symptoms were dyspnea, cough and hemoptysis. Fifty-nine percent of the patients developed extratracheal growth during the follow-up of 12 years, with lungs, neck, liver, and bones being the most common sites. In addition, autopsy revealed mediastinal metastases in 25% of patients. Vocal cord palsy at the time of diagnosis was present in 33%. The size and location of tumor in the trachea did not affect survival significantly. Patients with adenoid cystic carcinomas had the best prognosis.     

Liquid-phase hydrogenation of diethylbenzenes

Hydrogenation of diethylbenzenes in the liquid phase was studied at 358–418 K and 2–6 MPa over 16.7% Ni/Al₂O₃. The reactivity of diethylbenzene isomers was dependent on the mutual position of the substituents and decreased in the following order: 1,3- > 1,4- > 1,2-. The apparent activation energies were ca. 60 kJ/mol. The cis-to-trans ratio of the corresponding saturated products exhibited only a weak dependence on temperature and hydrogen pressure.     

Vortex Mutual Friction in Superfluid 3He

We give a full account of our extensive measurements of vortex mutual friction in rotating superfluid ³He, in both the A- and B-phases. The B-phase results are in qualitative agreement with a theory based on the concept of “spectral flow”; the agreement becomes quantitative if an effective energy gap of 0.63 Δ is used, but the Justification for such a substitution is not clear. The vortex core transition, at first not seen because of metastability and hysteresis, has now been observed. Detailed investigation suggests that the high temperature vortex state is a temperature dependent mixture of at least two vortex types. The A-phase mutual friction is found to be well described by two hydrodynamic coefficients, the orbital viscosity and the orbital inertia. The latter corresponds to an orbital angular momentum per Cooper pair of (0.0015 ± 0.0017 ) ħ, consistent with the prediction of the spectral flow theory. We find that the most uniform l texture is obtained by cooling through T_c while rotating, and then stopping rotation. Detailed investigation of textural memory effects shows that the uniform l-up and l-down textures are associated with opposite directions of rotation. We discuss the various types of texture that may be formed in our experiments. Finally, we compare our mutual friction results with those found in ⁴HeII.