The mechanism of the hydrogen-oxygen reaction II. The reaction occurring between the second and third explosion limits

1946 ◽  
Vol 185 (1003) ◽  
pp. 369-376 ◽  
Keyword(s):  
Preceding Paper ◽  
Experimental Results ◽  
New Method ◽  
Chain Mechanism ◽  
Experimental Conditions ◽  
The Third ◽  
Rate Expression ◽  
Explosion Limits ◽  
Explosion Limit

The equation for the rate of combination of hydrogen and oxygen, based upon the most probable chain mechanism, is very complicated and difficult to apply, without drastic approximations, to the experimental results. A new method of approach is here employed: the equation is factorized by considering first the condition for the third explosion limit (preceding paper) which allows the determination of most of the constants. With the help of these results the rate expression can be tested^ and the form of the function describing the initiating reaction examined. It is concluded that, under the experimental conditions, the chains are probably initiated by the dissociation of hydrogen: H 2 + M = 2H.

A new method for the determination of the specific kinetic energy (SKE) released to pyroclastic particles at magmatic fragmentation: theory and first experimental results

2011 ◽  
Vol 74 (4) ◽  
pp. 895-902 ◽  
Author(s):  
Tobias Dürig ◽  
Fabio Dioguardi ◽  
Ralf Büttner ◽  
Pierfrancesco Dellino ◽  
Daniela Mele ◽  
...  
Keyword(s):  
Kinetic Energy ◽  
Experimental Results ◽  
New Method ◽  
Specific Kinetic Energy

Study on Fluorimetric Method Determination of Glucose Molecule in Microchannels

2012 ◽  
Vol 443-444 ◽  
pp. 366-370
Author(s):  
Zheng Huang ◽  
Zhong Cheng Bai
Keyword(s):  
New Technology ◽  
Experimental Results ◽  
New Method ◽  
Fluorescent Detection ◽  
Exciting Light ◽  
Sodium Fluorescein ◽  
Biological Detection ◽  
Fluorimetric Method ◽  
Glucose Molecule

A new method of the fluorescent detection is introduced to use for detecting glucose molecule marked by fluorescence in microchannels. The fluorescent detection for glucose molecule is successfully realized in microchannels. The experiment results show that it is feasible to use sodium fluorescein marking the glucose molecule. At the same time, the experiment analyzes that experimental results have been influenced by wavelength of exciting light and acidity and basicity of solution. It is concluded that the glucose molecule marked with sodium fluorescein can be identified effectively in microchannels in this experiment. The new technology based on the study will lead to new application in bioanalysis and biological detection.

scholarly journals Experimental and Theoretical Methods of Lower Explosion Limit Determination in Gaseous and Liquid Fuels. A Review of the State of Knowledge

2016 ◽  
Vol 7 (4) ◽  
pp. 85-114 ◽  
Author(s):  
Marcin GRABARCZYK ◽  
Wiesława CIESIŃSKA ◽  
Rafał POROWSKI
Keyword(s):  
Past Research ◽  
Experimental Methods ◽  
The State ◽  
Liquid Fuels ◽  
Theoretical Methods ◽  
Explosion Limits ◽  
Explosion Limit

This work is an in-depth discussion of the experimental methods of lower explosion limit (LEL) determination and estimation in gases and the vapours of liquids. The focus here includes the dependences and drawbacks of each method. The work also outlines past research and discoveries that relate to the determination of explosion limits.

scholarly journals The mechanism of the hydrogen-oxygen reaction I. The third explosion limit

1946 ◽  
Vol 185 (1003) ◽  
pp. 353-369 ◽  
Keyword(s):  
Carbon Dioxide ◽  
Potassium Chloride ◽  
Fair Agreement ◽  
The Other ◽  
Satisfactory Description ◽  
The Third ◽  
Explosion Limits ◽  
Explosion Limit ◽  
Oxygen Reaction

One of the outstanding facts about the hydrogen-oxygen reaction is the existence of three distinct Explosion limits, designated, in order of increasing pressure, the first, second and third explosion limits. The influence on the third limit of ( a ) hydrogen-oxygen proportions, ( b ) additions of nitrogen, carbon dioxide and steam, has been examined: the measurements were made mainly at 586° in a silica vessel coated with potassium chloride (which controls the reaction chains). The results are qualitatively consistent with the theory that the third limit depends upon the (essentially isothermal) branching of reaction chains. An expression based upon the equations OH + H 2 = H 2 O + H, H + O 2 = OH + O, O + H 2 = OH + H, H + O 2 + M = HO 2 + M , HO 2 + H 2 =H 2 O + OH, together with the assumption that HO 2 diffuses to the walls of the vessel and is destroyed, leads to a satisfactory description of the third limit as well as of the other two. The constants characteristic of the various gases participating are in fair agreement with those derived by independent means.

Determination of Critical Points of Hypoeutectoid Steels / Wyznaczanie Punktów Krytycznych W Stalach Podeutektoidalnych

2012 ◽  
Vol 57 (4) ◽  
pp. 957-962 ◽  
Author(s):  
B. Pawłowski
Keyword(s):  
Critical Points ◽  
Separation Method ◽  
Experimental Results ◽  
New Method ◽  
New Approach ◽  
Hypoeutectoid Steel

The paper presents a new approach to interpretation of hypoeutectoid steel dilatograms upon heating between the austenite start and austenite finish temperatures. The proposed derivative curve separation method yields data which accords with the experimental results. Besides the new method appears a useful tool whereby it becomes possible to confirm the evidence reported earlier in literature that when a hypoeutectoid steel heats up to between the A1 and the A3 both ferrite and pearlite start to transform into austenite almost at the same time.

STUDIES ON SUSTAINED CONTRACEPTIVE EFFECTS WITH SUBCUTANEOUS POLYDIMETHYLSILOXANE IMPLANTS

1973 ◽  
Vol 73 (2) ◽  
pp. 347-359 ◽  
Author(s):  
G. Benagiano ◽  
M. Ermini ◽  
L. Carenza ◽  
P. Donini
Keyword(s):  
Urinary Excretion ◽  
Young Women ◽  
Ovarian Function ◽  
Megestrol Acetate ◽  
Bleeding Pattern ◽  
Experimental Conditions ◽  
The Third ◽  
Before And After

ABSTRACT Ovarian function was assessed in 10 healthy young women, before and after the insertion of 3 or 4 polydimethylsiloxane capsules filled with 20 mg of megestrol acetate. Each capsule released in vitro, approximately 20 μg/24 h of the hormone. Daily determination of the urinary excretion of FSH, LH, fractionated oestrogens and pregnanediol were performed in all subjects during one control cycle, the first and the third cycle after the insertion of the capsules. Out of 10, 8 control cycles were ovulatory according to all the parameters investigated. This compares with 15 ovulatory cycles out of a total of 20, examined after the insertion of the capsules. During treatment no changes were observed in the FSH excretion pattern; the mid-cycle LH peak was present in all ovulatory cycles, although it was usually much less evident under the action of megestrol acetate. The excretion of oestradiol was significantly increased in all subjects (P < 0.05) during the first cycle following implantation. Oestrone and oestriol excretion was also generally higher in patients bearing PDS capsules; however, this difference was not statistically significant. Pregnanediol levels were not affected by the treatment in all cycles considered to be ovulatory on the basis of all the parameters. The menstrual bleeding pattern did not change in the majority of cases. One patient had, during treatment with 3 capsules, two profuse break-through bleedings whereas another one became amenorrhoic two months after the insertion of 4 implants. It is concluded that megestrol acetate sustained release preparations do not inhibit ovulation under the experimental conditions used.

Study on Determination of Trace Cobalt in Environmental Water Samples after Separation/Enrichment Using Microcrystalline Phenolphthalein Modified with 8-Hydroxyquinoline

2013 ◽  
Vol 316-317 ◽  
pp. 279-285
Author(s):  
Xin Rong Wen ◽  
Chang Qing Tu
Keyword(s):  
Metal Ions ◽  
Spectrophotometric Determination ◽  
Water Samples ◽  
Environmental Water ◽  
New Method ◽  
Environmental Water Samples ◽  
Optimum Conditions ◽  
Experimental Conditions ◽  
Novel Method

The paper presents a novel method for the separation/enrichment of trace Co2+ using microcrystalline phenolphthalein modified with 8-hydroxyquinoline (HQ) prior to the determination by spectrophotometry. The effects of different parameters,such as the dosages of phenolphthalein and HQ,various salts and acidity on the enrichment yield of Co2+ have been investigated to select the experimental conditions. The possible enrichment mechanism of Co2+ was discussed.The results showed that under the optimum conditions, Co2+ could be quantificationally adsorbed on the surface of microcrystalline phenolphthalein in the form of the chelate precipitate of Co(HQ)2 ,while K+,Na+,Ca2+,Mg2+,Cd2+,Zn2+,Mn2+,Fe2+ and Al3+ could not be adsorbed at all.Therefore,Co2+ was completely separated from the above metal ions in the solution. A new method for the spectrophotometric determination of trace cobalt after separation/enrichment using microcrystalline phenolphthalein modified with 8-hydroxyquinoline was established.The proposed method has been successfully applied to the determination of Co2+ in various environmental water samples, and the results agreed well with those obtained by FAAS method.

scholarly journals A new method for rapeseed hulls purification – Proof of concept

OCL ◽  
2021 ◽  
Vol 28 ◽  
pp. 56
Author(s):  
Patrick Carré ◽  
Jean-Philippe Loison
Keyword(s):  
Rotation Speed ◽  
Operating Conditions ◽  
New Method ◽  
Process Efficiency ◽  
Proof Of Concept ◽  
Experimental Conditions ◽  
Industrial Implementation ◽  
Primary Separation ◽  
The One

The loss of fats in the hulls is one of the main obstacles limiting the industrial implementation of rapeseed dehulling. The main reason resides in the shape of rapeseed outer cotyledons which resemble to the hulls’ shape and make it difficult to separate. The purpose of this study is to propose a new method for the purification of rapeseed hulls. After primary separation by aspiration, the mixture of hulls and kernels is passed between a pair of flat rolls where kernels are flattened and stick to the metal while the hulls do not. We exploited this property to adapt a small laboratory flaker with two counter-rotating cylinders of 65 mm diameter with scrapers that make the kernels fall away from the hulls. Process optimization by tunning experimental conditions (hulls moisture content, roller spacing, roller speed and feed rate) allowed the determination of the optimal operating conditions. Experiments showed that wetting improves the purity of the hulls but reduces the one of the recovered kernels. A gap of 0.1 mm was necessary. In addition, it was shown that the sorting quality depends on the ratio flow-rate / rotation-speed. The best performances are reached around 1 g.s−1.rpm−1. In these conditions, the hulls and kernels purity were 96% and 94% respectively. This preliminary work has allowed us to prove the concept. The next step will be to develop a pilot plant to validate the process efficiency on a larger scale (100 kg/h).

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