Computer compilation of calibration tables for horizontal cylindrical containers

Translated from Izmeritel'naya Tekhnika, No. 4, pp. 31–32, April, 1990.     

Purification and some properties of membrane-bound and soluble pyrophosphatases of yeast vacuoles.

The membrane-bound and soluble pyrophosphatase (PPase) activities of Saccharomyces carlsbergensis vacuoles are determined by the functioning of special enzymes and are not due to non-specific PPi hydrolysis by other vacuolar phosphohydrolases. The molecular mass of the membrane-bound PPase is apparently 120,000 and its molecule consists of three subunits with Mr = 41,000. Soluble PPase has a molecular mass of about 82,000 and includes three subunits with Mr = 28,000. Both enzymes are glycoproteins. The vacuolar membrane-bound PPase is a proton pump.     

Comparison of Standards for Calculating Flow Rate and Amount with ISO Standards

ISO documents and standards are compared for calculating flow rates and amounts on the basis of gas distribution data for Moscow region. It is shown to be best to introduce Changes 1 into MI 2588-2000, which have been accepted by most of the TC 30 countries.     

Determining amounts of gases and liquids from integrator beadings

Translated from Izmeritel'naya Tekhnika, No. 2, pp. 33–34, February, 1988.     

Effects of Pipe Internal Roughness on Flow Rate and Quantity Measurements for a Single-Phase Medium

The paper considers the effects of internal roughness in a tube used in a measurement system containing constrictions on the measurement of flow rate in accordance with various standards. Methods are recommended for correcting for the roughness for MI 2588-2000, and the limits of applicability for them are quoted.     

Comparison of the Results of Natural Gas Flow Measurements in Compliance with Russian and ISO Standards

The results of measurements of natural gas flow rates in compliance with ISO/FDIS 5167-1/..4-2002(E) and GOST 8.563-97 are compared. An analysis is made on the basis of raw data typical of the operation of OAO Gazprom gas measuring stations. Control examples for corner and flange tapping of the preferential pressure across an orifice plate are given for circular-section conduits 400 and 500 mm in diameter.     

Inorganic polyphosphate and exopolyphosphatase in the nuclei of Saccharomyces cerevisiae: dependence on the growth phase and inactivation of the PPX1 and PPN1 genes

Nuclei of the yeast Saccharomyces cerevisiae possess inorganic polyphosphates (polyP) with chain lengths of ca. 10-200 phosphate residues. Subfractionation of the nuclei reveals that the most part of polyP is not associated with DNA. Transition of the yeast cells from stationary phase to active growth at orthophosphate (P(i)) excess in the medium is followed by the synthesis of the shortest polyP (<15 phosphate residues) and hydrolysis of the high-molecular polyP (>45 phosphate residues) in the nuclei. Nuclear exopolyphosphatase (exopolyPase) activity does not depend on the growth phase. The PPX1 gene encoding the major cytosolic exopolyPase does not encode the nuclear one and its inactivation has no effect on polyP metabolism in this compartment. Under inactivation of the PPN1 gene encoding another yeast exopolyPase, elimination of the nuclear exopolyPase is observed. The effect of PPN1 inactivation on the polyP level in the nuclei is insignificant in the stationary phase, while in the exponential phase this level increases 2.3-fold as compared with the parent strain of S. cerevisiae. In the active growth phase, no hydrolysis of high-molecular polyP is detected while the synthesis of short-chain polyP is retained. The data obtained indicate substantial changes in polyP metabolism in nuclei under the renewal of active growth, which only partially depends on the genes of polyP metabolism known to date.     

High-temperature reaction between silicon carbide and nitrogen under pressure

The effects of temperature and nitrogen pressure are studied on the SiC Si₃N₄ transformation of silicon carbide powders of various phase compositions, specific surface areas, and contents of mixtures. It is shown that the degree of transformation increases with nitrogen pressure up to 10 MPa and that, in all temperature and pressure ranges of nitrogen, it is higher for bulk free powder than the preliminarily compacted material. In 30–60 min, a complete transformation of SiC into Si₃N₄ occurs under 10 MPa nitrogen pressure and at 1650–1750°C temperature.Institute of Inorganic Chemistry, Slovakian Academy of Sciences. Institute of Superhard Materials, Ukrainian Academy of Sciences, Kiev. Translated from Poroshkovaya Metallurgiya, No. 4(364), pp. 1–6, April, 1993.     

Detection and some properties of membrane-bound and soluble polyphosphatases in mitochondria of the yeast Saccharomyces cerevisiae

Saccharomyces cerevisiae mitochondria possess polyphosphatases that are tightly bound to the membranes and differ from soluble polyphosphatase of these organelles in a number of properties. Molecular weights of the membrane-bound polyphosphatases are 120 and 76 kD, and the molecular weight of the soluble polyphosphatase is about 36 kD. All three enzymes are evidently monomers, since antibodies against purified cell-envelope polyphosphatase of S. cerevisiae reacted with 115, 78, and 37 kD polypeptides in immunoblotting. The activities of membrane-bound and soluble polyphosphatase are maximal at neutral pH. The soluble polyphosphatase activity is stimulated by divalent cations, unlike the membrane-bound enzymes which are inhibited by the same cations including Mg2+. Monovalent cations do not affect the activity of the soluble enzyme but stimulate polyphosphatases in the membrane preparation. The specific activities for hydrolysis of polyphosphates with average chain lengths of 9 to 188 phosphate residues are enhanced by increasing the degree of substrate polymerization in the case of the membrane preparation and are unchanged in case of the soluble enzyme. Affinity of the soluble enzyme to polyphosphates is 5-10 times higher than that of the membrane-bound polyphosphatases. In the soluble fraction of mitochondria, high tripolyphosphatase activity is detected which is approximately 80% of that in isolated mitochondria.