Extremely Small Amounts Research Articles

Control of One-Handed Helicity in Polyacetylenes: Impact of an Extremely Small Amount of Chiral Substituents.

Controlling the one-handed helicity in synthetic polymers is crucial for developing helical polymer-based advanced chiral materials. We now report that an extremely small amount of chiral biphenylylacetylene (BPA) monomers (ca. 0.3-0.5 mol %) allows complete control of the one-handed helicity throughout the polymer chains mostly composed of achiral BPAs. Chiral substituents introduced at the 2-position of the biphenyl units of BPA positioned in the vicinity of the polymer backbones contribute to a significant amplification of the helical bias, as interpreted by theoretical modeling and simulation. The helical structures, such as the helical pitch and absolute helical handedness (right- or left-handed helix) of the one-handed helical copolymers, were unambiguously determined by high-resolution atomic force microscopy combined with X-ray diffraction. The exceptionally strong helix-biasing power of the chiral BPA provides a highly durable and practically useful chiral material for the separation of enantiomers in chromatography by copolymerization of an achiral functional BPA with a small amount of the chiral BPA (0.5 mol %) due to the robust helical scaffold of the one-handed helical copolymer.

Studies on Eco-Friendly Grinding with an Extremely Small Amount of Coolant – Applicability of Contact-Type Flexible Brush-Nozzle –

This study considers an innovative coolant nozzle that enables a remarkable reduction in grinding fluid consumption in cylindrical plunge grinding of chromium molybdenum steel (ISO 34CrMo4 / JIS SCM435) using a vitrified-bonded cubic boron nitride (CBN) wheel. This coolant nozzle has a simple structure consisting of ordinary nylon or polypropylene fiber brushes and an acrylic resin oil pool. This flexible brush-nozzle is suitably placed in contact with the wheel surface, and the grinding fluid is supplied along the brush to the wheel surface to form a fluid film to the wheel surface, while simultaneously scraping the “air belt.” Thus, the grinding fluid adheres to the whole wheel surface by the “Coandă effect,” and grinding fluid consumption is reduced to 0.5 L/min or less without causing any thermal damage to the ground surface. The cooling effect of this coolant nozzle is examined mainly by a grinding temperature measurement by means of a fiber-coupled two-color pyrometer. The nylon fiber brush is more effective than the polypropylene brush because of its high elasticity and good water absorption rate, which is related to the wettability. Even with such an extremely small amount of grinding fluid, the grinding force, surface roughness, and grinding temperature are nearly the same as those in the case of the conventional wet grinding.

Simulation of Extremely Small Amounts of Snow Observed at High Elevations over the Japanese Northern Alps in the 2015/16 Winter

Simulation of Extremely Small Amounts of Snow Observed at High Elevations over the Japanese Northern Alps in the 2015/16 Winter

Relationship between Cell Recovery Rate and Increase in Cell Viability After Exposure of Extremely Small Amounts of 4 Metals

Relationship between Cell Recovery Rate and Increase in Cell Viability After Exposure of Extremely Small Amounts of 4 Metals

Electro-Polishing Foil Samples for TEM with an Extremely Small Amount of Electrolyte

Extended abstract of a paper presented at Microscopy and Microanalysis 2013 in Indianapolis, Indiana, USA, August 4 – August 8, 2013.

Turning Using Extremely Small Amounts of Cutting Fluids.

Cutting fluids are essential in metal cutting to increase the tool life and reduce the finished surface roughness.Due to increasingly strict legislation aiming at controlling environmental pollution, however, the cost of using cutting fluids is rising.Therefore, it is necessary to reduce the amounts of the cutting fluid used.In this study, we propose a method in which cooling and lubrication can be achieved using extremely small amounts of cutting fluids.The effect of the proposed method is investigated through experiment.

Turning using Extremely Small Amounts of Cutting Fluid.

Cutting fluid are essential in metal cutting to increase the tool life and reduce the finished surface roughness. Due to increasingly strict legislation aimed at controlling environmental pollution, however, the cost of using cutting fluid is rising. Therefore, it is necessary to reduce the amounts of cutting fluid used. In this study, we propose a method in which cooling and lubrication are achieved using extremely small amounts of cutting fluid. The effect of the proposed method is investigated through experiment.

A Method for Preparing A Large Sized, Uniform and Stable Built-up Film of 109Cd Icosanoate as A Radioactive Source by Utilization of an Extremely Small Amount of Substrate Solution

Abstract A stable radioactive source in vacuo was obtained by a modified horizontal lifting method of Langmuir-Blodgett (L/B) film. In spite of the slight consumption of the substrate solution (only 2–2.5 ml) for preparing a 15 mm×25 mm sized L/B film containing four molecular layers of 109Cd icosanoate, the deposition of the film was complete. The reliability of the deposited films by this method was confirmed by their radioactivities, deposition ratios and autoradiographs. The condition to obtain a larger sized homogeneous L/B film (20–25 mm×102 mm) was also examined. Two or four molecular layers of nonradioactive Cd icosanote deposited on the L/B film of 109Cd icosanoate did not influence the intensity of the γ-ray of 88.0 KeV. Concequently, it is possible to obtain the high radioactive source by the deposition of the multilayers of 109Cd icosanoate. Spectra of L2 and L3 conversion electrons from the 109Cd in its built-up film were also determined. In conclusion, the present depositing method for the L/B film is excellent for the manufacturing the radioactive source and thought to be also applicable for the deposition of other valuable materials.

Inhibition of Release of Luteinizing Hormone in the Male Rat by Extremely Small Amounts of Arginine Vasotocin: Further Evidence for the Involvement of 5-Hydroxytryptamine-Containing Neurons in the Mechanism of Action of Arginine Vasotocin

A single injection of 10-4 pg synthetic arginine vasotocin (AVT) into the third ventricle of urethane anesthetized male rats, significantly decreased plasma LH levels between 15–60 min after the injection, while plasma FSH levels remain unchanged. At 120 min, plasma LH levels returned to their preinjection levels. In the range tested, the effects of AVT seem to be dose dependent, because 10-5 pg induce a less pronounced decrease of plasma LH levels than 10-4 pg, and 10 pg did not decrease plasma LH levels. No effects on plasma LH levels could be detected when amounts of AVT between 10-1–10-4 pg were injected into the pituitary. Neither synthetic arginine vasopressin nor oxytocin, injected into the third ventricle in amounts between 10-3–10-4 pg, was able to affect plasma LH levels. The increase of plasma LH levels induced by exogenous LHRH was not significantly affected by the previous intraventricular injection of AVT. When 10-4 pg AVT were injected into the third ventricle of rats treated 48 h earlier with p-chlorophenylalanine (p-CPA), no effects on plasma LH levels could be detected. Administration of 5-hydroxytryptophan to p-CPA-treated rats, 1 h before the injection of AVT partially restored the ability of AVT to decrease plasma LH levels. The hypothalamic 5-hydroxytryptamine (5-HT) content of normal rats as well as that of rats treated with p-CPA and 5-hydroxytryptophan significantly increased at 30 min after the intraventricular injection of 10-4 pg AVT. No effects on hypothalamic 5-HT content could be detected after the intraventricular injection of 10-4 pg AVT in rats treated with p-CPA alone. The results of the present work suggest that AVT injected into the third ventricle of male rats at the lowest effective concentrations so far reported for an active biological substance decreases plasma LH levels by inhibiting the release of LHRH in the brain and not by interfering directly with the release of LH at the pituitary level. Evidence is provided that AVT induces these effects by interfering with 5- HT neurotransmission in the brain.

The Detection of Extremely Small Amount of Impurities by Means of An Omegatron Mass Spectrometer

An omegatron mass spectrometer was employed to detect some extremely small amount of impurities in solids. The gases evolved during a vacuum heat treatment of extra pure samples of oxides, sulfides, and selenides, were analyzed by means of the omegatron mass spectrometer. The detected gases have been NH3, NO, H2S, CO, CO2, CS2, HCl, H2O, and hydrocarbons. The origin of these gases are discussed as follows ; (1) the gases produced by thermal decomposition of reactants which were remained after the sample was made by dry process and/ or the evolution of gaseous imprities which were included during wet process. (2) the gaseous products produced by chemical reaction of impurities with the sample. (3) the evolution of adsorbed gases. (4) the evolution of reagent which was used to store the sample, (5) residual gases in the vacuum system.The amount of gas evolved (QQ) from these samples was estimated as follows ; in the case of flow method, Q = S∫Pdt and in the case of static method, Q= PV. The consideration on ideal cases shows that smaller amount of impurities less than 1 ppb of the material is detectable. The sensitivity of this method has been.shown to be high and the method has been found to be useful in detection of traces of gaseous impurities less than 1 ppm.Possible sources of error in quantitative analysis are disct ssed as follows; (1) the gaseous imp, rities remain after the evolution of first heating cycle. (2) the absolute meas Irements of partial pressure and of pumping.speed are difficult for active gases.

The Determination of Extremely Small Amounts of Phosphorus by the Official Method

Journal Article The Determination of Extremely Small Amounts of Phosphorus by the Official Method Get access R C Wiley R C Wiley University of Maryland, College Park, Md. Search for other works by this author on: Oxford Academic Google Scholar Journal of Association of Official Agricultural Chemists, Volume 5, Issue 4, 15 May 1922, Pages 465–466, https://doi.org/10.1093/jaoac/5.4.465 Published: 10 March 2020