DETERMINATION OF RELATIVE PORE SIZE IN LIVING MEMBRANES OF NITELLA BY THE TECHNIQUES OF ELECTROOSMOSIS AND RADIOACTIVE TRACERS

1967 ◽  
Vol 45 (8) ◽  
pp. 1267-1275 ◽  
Author(s):  
D. S. Fensom ◽  
D. J. Ursino ◽  
C. D. Nelson
Keyword(s):  
Carbon Tetrachloride ◽  
Pore Size ◽  
Indoleacetic Acid ◽  
The Other ◽  
Water Molecules ◽  
Radioactive Tracers ◽  
Before And After ◽  
Nitella Flexilis ◽  
In Cells

By measuring the number of water molecules per ion moved electroosmotically through living membranes of Nitella flexilis before and after the addition of chemicals to a solution of 10−4 M KCl, the effect of the chemical upon electroosmotic transport was investigated. Carbon tetrachloride and chloroform reduced slightly the amount of water transported per ion. On the other hand 10−5 M indoleacetic acid caused major changes in electroosmotic transport, increasing it in cells tested in July–August, but decreasing it in cells tested in October–November. Different ions also carry different amounts of water with them electroosmotically. These changes can be interpreted in terms of changing pore size.The relative pore size was also determined by measuring the permeation of glucose-14C and sucrose-14C in the absence and presence of electroosmotic transport and in cells treated with indoleacetic acid. Both the plasmalemma and tonoplast were freely permeable to glucose-14C but not to sucrose-14C. However, in the presence of electroosmotic transport sucrose did permeate the cell membrane. Indoleacetic acid enhanced this permeation of sucrose-14C.

Determination of Small Bone Particles in Meat

1968 ◽  
Vol 51 (6) ◽  
pp. 1175-1177 ◽  
Author(s):  
Robert M Hill ◽  
B D Hites
Keyword(s):  
Carbon Tetrachloride ◽  
Meat Products ◽  
The Other ◽  
Small Particles ◽  
Bone Content ◽  
Bone Particles ◽  
Small Bone ◽  
Good Agreement

Abstract Very small particles of bone can be separated from ground meats and meat products by the following procedure: The bulk of the meat is solubilized by digestion with papain and the bone is separated from the other nondigestible material according to its ability to settle in a carbon tetrachloride: acetone mixture. Turkey samples with widely varying bone content were analyzed, with good agreement between duplicate samples.

The determination of the volume and air space of soil clods

1944 ◽  
Vol 34 (3) ◽  
pp. 123-132 ◽  
Author(s):  
E. W. Russell ◽  
W. Balcerek
Keyword(s):  
Moisture Content ◽  
Farmyard Manure ◽  
The Other ◽  
Available Water ◽  
Air Space ◽  
Before And After ◽  
Hydrocarbon Oil

A method is described for determining the field volume and the air space of a clod of any shape by filling its pores with a hydrocarbon oil, such as paraffin or tetralin, and determining its weight in the oil and in air before and after impregnation. The method appears to work well for clods of any moisture content.This method is shown to give values of these volumes entirely comparable with those given by the other accurate methods described in the literature. Its accuracy for clods of Rothamsted soil, weighing between 20 and 500 g., was probably at least 1 part per thousand, i.e. 0-1%.The method has been applied to the determination of the available water held by a soil and has been used to illustrate the effect of long-continued applications of farmyard manure to a soil in increasing the amount of available water it can hold.

Determination of the milk yield of sows and correction for loss of weight due to metabolic processes of piglets during suckling

1964 ◽  
Vol 6 (1) ◽  
pp. 119-123 ◽  
Author(s):  
R. L. Van Spaendonck ◽  
F. X. Vanschoubroek
Keyword(s):  
Milk Yield ◽  
The Body ◽  
The Other ◽  
Weight Changes ◽  
Metabolic Processes ◽  
Loss Of Weight ◽  
Before And After ◽  
The One ◽  
The Relationship

SUMMARYIn determining the milk yield of the sow by weighing the litter before and after suckling, loss of weight due to metabolic processes must be considered.An experiment is described to investigate the loss of weight of piglets caused by metabolic processes between two consecutive weighings, and to investigate the relationship between this loss on the one hand and the body weight and the age of the piglets on the other. Weight changes of 15 litters of average 9·8 piglets were studied during 66 weighing periods of 16 minutes, by putting the pigs in a cage, fixed on a differential balance. Each weighing period consisted of 8 periods of 2 minutes, so that in all, loss of weight was studied during 528 2-minute periods.

scholarly journals Investigations of infra-red spectra. Determination of C-H frequencies (~3000 cm. -1 ) in paraffins and olefins, with some observations on “polythenes”

1940 ◽  
Vol 175 (961) ◽  
pp. 208-233 ◽  
Keyword(s):  
Double Bond ◽  
Carbon Tetrachloride ◽  
General Type ◽  
The Other ◽  
Hydrogen Atoms ◽  
Wave Numbers ◽  
Infra Red ◽  
Modes Of Vibration ◽  
Single Bonds

In a previous communication (1938) we described the results of an investigation into the infra-red absorption in the region of 3 µ of a number of hydrocarbons dissolved in carbon tetrachloride, with special reference to the absorption of ⟩CH 2 groups in different molecules. It was found that in many simple compounds the CH 2 group gave rise to two frequencies, essentially C-H valency vibrations, about 2857 and 2927 cm. -1 , and that from one compound to another these frequencies varied by only a few wave numbers. The lower frequency was identified with the mode of vibration in which the hydrogen atoms move in phase, while the other frequency was taken as the unsymmetrical mode of vibration. This assignment was substantiated by calculations with potential functions for molecules of the general type CH 2 — X , where X represents the rest of the molecule and is attached to the CH 2 group by single bonds. It was found that the CH frequencies of a CH 2 group are but little affected by the nature of X in saturated compounds, but that when the CH 2 group is attached to X by a double bond the CH frequencies are some 150 cm. -1 higher. In ethylene each CH 2 group has two CH valency modes of vibration, and since the CH 2 groups themselves can vibrate in or out of phase with one another, four CH frequency modes are possible for the C 2 H 4 molecule, two being Raman active and two infra-red active. In many molecules containing several CH 2 groups, similar coupling effects are important, and frequently four infra-red CH frequencies are observed.

scholarly journals Redetermination of nickel(II) formate dihydrate

IUCrData ◽  
2018 ◽  
Vol 3 (3) ◽  
Author(s):  
Matthias Weil
Keyword(s):  
Crystal Structure ◽  
Hydrogen Bonding ◽  
Hydrogen Bonds ◽  
Structure Determination ◽  
Three Dimensional ◽  
The Other ◽  
Water Molecules ◽  
Hydrogen Bonding Pattern ◽  
Medium Strength

In comparison with the previous structure determination of poly[diaquadi-μ-formato-nickel(II)], [Ni(HCOO)2(H2O)2]n, based on Weissenberg film data [Krogmann & Mattes (1963).Z. Kristallogr.118, 291–302], the current redetermination from modern CCD data revealed the positions of the H atoms, thus making a detailed description of the hydrogen-bonding pattern possible. Both Ni2+cations in the crystal structure are located on inversion centres and are octahedrally coordinated. One Ni2+cation is bound to six O atoms of six formate anions whereas the other Ni2+cation is bound to four O atoms of water molecules and to two formate O atoms. In this way, the formate anions bridge the two types of Ni2+cations into a three-dimensional framework. O—H...O hydrogen bonds of medium strength between water molecules and formate O atoms consolidate the packing.

A STUDY OF THE DETERMINATION OF VITAMIN A BY SPECTROPHOTOMETRY AND BY PHOTOELECTRIC COLORIMETRY

1938 ◽  
Vol 16b (12) ◽  
pp. 422-431
Author(s):  
W. D. McFarlane ◽  
A. J. Sutherland
Keyword(s):  
Vitamin A ◽  
Extinction Coefficient ◽  
Ultra Violet ◽  
The Other ◽  
Unsaponifiable Fraction ◽  
Complete Destruction ◽  
Significant Difference ◽  
Before And After ◽  
Absorption Measurements

A comparison has been made of the determination of vitamin A in cod-liver oils and concentrates of vitamin A by means of (a) extinction coefficient measurements at 3280 Å, and (b) photoelectric colorimetry. Both methods are shown to yield results of equal accuracy, but with cod-liver oils special precautions have to be taken in the preparation and purification of the unsaponifiable fraction. No significant difference was found between the means of the quotients, blue value/E value, for low potency cod-liver oils and those for concentrates.The estimation of vitamin A by direct spectrophotometric measurements before and after its destruction by intense ultra-violet irradiation has been investigated. The conditions are described which permitted the complete destruction of vitamin A in a concentrate with apparently no significant effect on the other absorbing constituents of the oil except carotene. The residual absorption after irradiation amounted to about 5% of the initial absorption. With cod-liver oils the values obtained by this method are 20 to 30% lower than those obtained by absorption measurements on the unsaponifiable fraction. The results obtained with the concentrate indicate that a correction may be applied which reduces the discrepancy to about 10 to 15%.

Comparison of Human Panels, Colorimeter and near Infrared Spectroscopy for the Evaluation of Fabric Stain Removal

1994 ◽  
Vol 2 (2) ◽  
pp. 101-118 ◽  
Author(s):  
K.A. Bunding Lee ◽  
Jeanne O'Brien ◽  
C.L. Kuesten ◽  
John Sramek ◽  
Mary H. Luccas ◽  
...  
Keyword(s):  
Infrared Spectroscopy ◽  
Data Storage ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
The Other ◽  
Computer Data ◽  
Stain Removal ◽  
Before And After ◽  
Stain Analysis

Near infrared (NIR) spectroscopy was used to analyse fabric stain samples used in a fabric stain prespotter test in which a colorimeter and human panels were used to evaluate the cleaning ability of the prespotters. The purpose of this was to see if the NIR results compared well with the other two techniques and could then be used instead for fabric stain analysis. NIR/visible instruments offer several advantages including determination of coloured and uncoloured components of the stains, ease of comparing the stain before and after cleaning, fast, accurate, reproducible and quantitative analysis, and computer data storage for later comparison. Although the samples were not specifically prepared for this determination, the NIR did give comparable results to the other two techniques for many of the stains analysed.

scholarly journals Analysis of Carbon Tetrachloride-Extractable Species from Daxing Bituminous Coal

2020 ◽  
Vol 10 (2) ◽  
pp. 494
Author(s):  
Caixia Jv ◽  
Fenggang Li ◽  
Peng Yan ◽  
Mengmeng Fan ◽  
Linlin Jia ◽  
...  
Keyword(s):  
Carbon Tetrachloride ◽  
Soxhlet Extraction ◽  
Extraction Methods ◽  
The Other ◽  
Radical Mechanism ◽  
Free Radical Mechanism ◽  
Assisted Extraction ◽  
Before And After ◽  
Ultrasonic Assisted ◽  
Extraction Processes

Soxhlet extraction (SE), ultrasonic-assisted extraction (UAE), and microwave-assisted extraction (MAE) were carried out on Daxing coal with carbon tetrachloride. The extracted components were analyzed by GC-MS while the residues of the coal after extractions were analyzed by FT-IR spectroscopy. The obtained IR spectra indicated that the functional groups were barely changed in strength for the coal before and after extractions concluding that the macromolecular structures of coal were not destroyed in the extraction processes. XRD diagrams showed the peak around θ = 47 was totally disappeared by all the three extractions, indicating that the graphite-like structural substances in the coal were totally destroyed in the extraction processes. GC/MS analysis showed that: (1) The SE method extracted the least number of substances from the coal; on the other hand, the extracted compounds are largely chlorinated which can be explained by the free radical mechanism. (2) MAE extracted 75 organic compounds of which 53 are oxygen-containing substances. A small portion of non-alkanes (1.19%) was found, which is in contrast to the other two extraction methods. Moreover, a few biomarker compounds were also identified including hexaoxane, 2-methylcholest-3-ene, 6,9,12-tripropylheptadecane, and 17α-21β-28,30-bisnorhopane. (3) The three extraction methods gave totally different extraction patterns for the same coal, highlighting that the extraction method can dominate the outcome of the extracted products. The mechanisms behind these extraction processes are discussed. This study provides a base for the future choice of the extraction methods in terms of outcomes of the extraction products.

Heat debt during cold air exposure before and after cold water immersions

1991 ◽  
Vol 71 (1) ◽  
pp. 60-68 ◽  
Author(s):  
P. Tikuisis ◽  
D. H. McCracken ◽  
M. W. Radomski
Keyword(s):  
Cold Water ◽  
Heat Content ◽  
The Other ◽  
Air Exposure ◽  
Cold Air ◽  
Method Of Calculation ◽  
Young Males ◽  
Methods Of Calculation ◽  
Before And After

Acclimation to cold can manifest itself in several different ways, insulative and metabolic being the most common. Bittel (J. Appl. Physiol. 62: 1627–1634, 1987) has demonstrated that heat debt, which encompasses both heat production and heat loss, can be used as a unitary index of acclimation. However, conflicting results are obtained if heat debt is calculated using a mean-weighted body temperature (Tb) vs. the change of body heat content through the integration of heat storage (S). The present study examines the determination of heat debt by three methods of calculation, the first based on Tb and the other two based on S where heat losses are measured in one and predicted in the other. Data were obtained from five healthy young males exposed to 10 degrees C air for 2 h on four different occasions. The first two exposures provided control data, while the last two were performed after 5 and 10 days, respectively, of daily immersions in 15 degrees C water to induce acclimation. The variability in response between the control exposures was as large as that among the other exposures. Although the method of calculation using Tb indicated that subjects were close to a thermal balance after 2 h of cold air exposure, this contrasted sharply with the result of the other two methods that indicated heat debt was still increasing steadily. The latter two methods are considered more accurate for transient heat debt calculation. Although cases of individual acclimation were found, these were different among the subjects, resulting in pooled responses that indicated no group acclimation by means of any of the three methods of calculation.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals METHYL MERCURY IN GREEN MUSCLE (Mytilus viridis L.) FROM FISH MARKET MUARA ANGKE : BEFORE AND AFTER COOKING

2010 ◽  
Vol 9 (1) ◽  
pp. 77-83
Author(s):  
Ermin K. Winarno ◽  
Winarti Andayani ◽  
Agustin Sumartono
Keyword(s):  
Gas Chromatography ◽  
Mercury Concentration ◽  
Methyl Mercury ◽  
Mercury Content ◽  
The Other ◽  
Fish Market ◽  
Cooking Process ◽  
Before And After ◽  
Hcl Solution

The determination of methyl mercury content in green muscle (Mytilus viridis L.) that were taken from Pasar Pelelangan Ikan Muara Angke, Jakarta Bay has been carried out. Sampling was taken in November 2005 and March 2006, the samples were bought from the green muscle sellers. The aim of this research is to know the effect of cooking on the content of methyl mercury in green muscle. Samples were homogenized, weighed and washed with aceton and toluene. After washing, the homogenized material was added with HCl solution, extracted with toluene, then the methyl mercury content in toluene extract was analyzed using gas chromatography. The results of this research showed that methyl mercury concentration in raw and cooked green muscle respectively were 0.803 + 0.019 mg/g and 0.443 + 0.035 mg/g (in November 2005) and 0.096 + 0.014 mg/g and 0.079 + 0.016 mg/g (in March 2006) respectively. The methyl mercury content in raw (in November 2005) was higher than in cooked green muscle as permitted concentration in the sea biota by WHO and FAO, it is 0.5 ppm (mg/g), on the other hand the result of the second sampling in March 2006 showed that methyl mercury content in green muscle was lower than permitted concentration. Cooking process of the green muscle decreased methyl mercury content 44.85% (sampling in November 2005) and 17.71% (sampling in March 2006), because methyl mercury that bonded to protein were distributed to boiling water. Methyl mercury content in green muscle after cooking was still lower than the permitted concentration.   Keywords: methyl mercury, green muscle, Mytilus viridis L., Muara Angke

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