REACTIONS OF ARYLSULPHONIC ESTERS: VII. THE HEAT CAPACITY OF ACTIVATION FOR THE ETHANOLYSIS OF METHYL p-NITROBENZENESULPHONATE

1957 ◽  
Vol 35 (7) ◽  
pp. 623-629 ◽  
Author(s):  
J. B. Hyne ◽  
R. E. Robertson
Keyword(s):  
Heat Capacity ◽  
Temperature Coefficient ◽  
Nonaqueous Media ◽  
Conductometric Method ◽  
Better Than

A conductometric method is described for the determination of rates of solvolyses in nonaqueous media with an accuracy of better than ± 0.5% in k. The heat of activation derived from the results so obtained is shown to have a temperature coefficient (ΔCp‡) of −21 cal./mole deg.

Aqueous Solutions of Nonpolar Compounds. Heat-Capacity Effects

1972 ◽  
Vol 50 (2) ◽  
pp. 133-138 ◽  
Author(s):  
R. D. Wauchope ◽  
R. Haque
Keyword(s):  
Heat Capacity ◽  
Temperature Coefficient ◽  
Solution Process ◽  
Positive Temperature Coefficient ◽  
Heat Capacity Change ◽  
Positive Temperature ◽  
Capacity Change ◽  
Heat Capacity Changes ◽  
Nonpolar Compounds ◽  
Better Than

The method of Clarke and Glew has been used to obtain estimates of the precision of measurement of the thermodynamic functions for the solution of hydrocarbons, the noble gases, and inert diatomic gases in water. In some cases, the precision of the data is such that a statistically significant value for the temperature coefficient of the heat-capacity change for the solution process is obtained. Comparison with the theory of Nemethy and Scheraga shows that their calculations of heat-capacity changes at 25 °C are better than previously believed, but that their prediction of a positive temperature coefficient for this quantity is in contradiction with most data.

THE THERMAL CONDUCTIVITY OF NAPALM–GASOLINE GELS

1948 ◽  
Vol 26a (2) ◽  
pp. 50-59 ◽  
Author(s):  
G. O. Langstroth ◽  
F. Zeiler
Keyword(s):  
Thermal Conductivity ◽  
Temperature Coefficient ◽  
Small Diameter ◽  
Temperature Coefficient Of Resistance ◽  
Simple Method ◽  
Viscous Liquids ◽  
Low Viscosity ◽  
Tungsten Filaments ◽  
Better Than

A slightly modified form of the rapid and simple method suggested by Hutchinson for the measurement of the thermal conductivity of liquids has been found to suffer from convection effects with samples of low viscosity, except with conductivity tubes of very small diameter. For more viscous liquids such as glycerol it was found to be adequate under all conditions studied. The method has been applied in the determination of the conductivity of Napalm–gasoline gels. For temperatures T between − 50° and 50 °C., and Napalm concentrations C between 0 and 10%, the conductivity k in cal. sec.−1 cm.−1 per degree C. is described to better than 1% by the relation, k × 105 = 29.7 − 0.068 T + 0.11 C. The temperature coefficient of resistance of the unaged tungsten filaments used in the tubes differed considerably from the value given by the International Critical Tables for aged tungsten filaments. For temperatures T0 between − 50° and 50 °C., the coefficient α0 per degree C. is given to better than 1% by the relation, [Formula: see text].

Time and Latitude in South Africa

1972 ◽  
Vol 1 ◽  
pp. 27-38
Author(s):  
J. Hers
Keyword(s):  
South Africa ◽  
Cape Town ◽  
Astronomical Observations ◽  
Royal Observatory ◽  
The Republic ◽  
Astronomical Determination ◽  
Limited Accuracy ◽  
Better Than

In South Africa the modern outlook towards time may be said to have started in 1948. Both the two major observatories, The Royal Observatory in Cape Town and the Union Observatory (now known as the Republic Observatory) in Johannesburg had, of course, been involved in the astronomical determination of time almost from their inception, and the Johannesburg Observatory has been responsible for the official time of South Africa since 1908. However the pendulum clocks then in use could not be relied on to provide an accuracy better than about 1/10 second, which was of the same order as that of the astronomical observations. It is doubtful if much use was made of even this limited accuracy outside the two observatories, and although there may – occasionally have been a demand for more accurate time, it was certainly not voiced.

Determination of trace concentrations of copper by FIA-FAAS after preconcentration on chelating sorbents

1989 ◽  
Vol 54 (7) ◽  
pp. 1785-1794 ◽  
Author(s):  
Vlastimil Kubáň ◽  
Josef Komárek ◽  
Zbyněk Zdráhal
Keyword(s):  
Sampling Frequency ◽  
Copper Determination ◽  
Flow Rates ◽  
Sample Injection ◽  
Injection Flow ◽  
Chelating Sorbents ◽  
Set Up ◽  
Trace Concentrations ◽  
Better Than

A FIA-FAAS apparatus containing a six-channel sorption equipment with five 3 x 26 mm microcolumns packed with Spheron Oxin 1 000, Ostsorb Oxin and Ostsorb DTTA was set up. Combined with sorption from 0.002M acetate buffer at pH 4.2 and desorption with 2M-HCl, copper can be determined at concentrations up to 100, 150 and 200 μg l-1, respectively. For sample and eluent flow rates of 5.0 and 4.0 ml min-1, respectively, and a sample injection time of 5 min, the limit of copper determination is LQ = 0.3 μg l-1, repeatability sr is better than 2% and recovery is R = 100 ± 2%. The enrichment factor is on the order of 102 and is a linear function of time (volume) of sample injection up to 5 min and of the sample injection flow rate up to 11 ml min-1 for Spheron Oxin 1 000 and Ostsorb DTTA. For times of sorption of 60 and 300 s, the sampling frequency is 70 and 35 samples/h, respectively. The parameters of the FIA-FAAS determination (acetylene-air flame) are comparable to or better than those achieved by ETA AAS. The method was applied to the determination of traces of copper in high-purity water.

scholarly journals Measuring the quartic Higgs self-coupling at a multi-TeV muon collider

2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
M. Chiesa ◽  
F. Maltoni ◽  
L. Mantani ◽  
B. Mele ◽  
F. Piccinini ◽  
...  
Keyword(s):  
Higgs Boson ◽  
Center Of Mass ◽  
Mass Energy ◽  
Simple Analysis ◽  
Proton Proton ◽  
Coupling Interaction ◽  
Center Of Mass Energy ◽  
Muon Collider ◽  
Better Than

Abstract Measuring the shape of the Higgs boson potential is of paramount importance, and will be a challenging task at current as well as future colliders. While the expectations for the measurement of the trilinear Higgs self-coupling are rather promising, an accurate measurement of the quartic self-coupling interaction is presently considered extremely challenging even at a future 100 TeV proton-proton collider. In this work we explore the sensitivity that a muon collider with a center of mass energy in the multi-TeV range and luminosities of the order of 1035cm−2s−1, as presently under discussion, might provide, thanks to a rather large three Higgs-boson production and to a limited background. By performing a first and simple analysis, we find a clear indication that a muon collider could provide a determination of the quartic Higgs self-coupling that is significantly better than what is currently considered attainable at other future colliders.

scholarly journals Performance of the SoLid reactor neutrino detector

2019 ◽  
Vol 219 ◽  
pp. 08003
Author(s):  
Maja Verstraeten
Keyword(s):  
Quality Control ◽  
Energy Resolution ◽  
Neutrino Detector ◽  
Channel Response ◽  
In Situ Calibration ◽  
Reactor Neutrino ◽  
Li Isotope ◽  
Better Than

The SoLid Collaboration is currently operating a 1.6 ton neutrino detector near the Belgian BR2 reactor. Its main goal is the observation of the oscillation of electron antineutrinos to previously undetected flavour states. The highly segmented SoLid detector employs a compound scintillation technology based on PVT scintillator in combination with LiF-ZnS(Ag) screens containing the 6Li isotope. The experiment has demonstrated a channel-to-channel response that can be controlled to the level of a few percent, an energy resolution of better than 14% at 1 MeV, and a determination of the interaction vertex with a precision of 5 cm. This contribution highlights the major outcomes of the R&D program, the quality control during component manufacture and integration, the current performance and stability of the full-scale system, as well as the in-situ calibration of the detector with various radioactive sources.

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