A modified chromic oxide indicator ratio technique for accurate determination of nutrient digestibility

1993 ◽  
Vol 73 (4) ◽  
pp. 1001-1004 ◽  
Author(s):  
Dhanonjoy C. Saha ◽  
Rex L. Gilbreath
Keyword(s):  
Key Words ◽  
Accurate Determination ◽  
Nutrient Digestibility ◽  
Chromic Oxide ◽  
Modified Method ◽  
Fecal Recovery ◽  
Indicator Minerals ◽  
Indicator Ratio ◽  
Chromium Recovery

A modified method for nutrient digestibility determination is described. The method considers analytical chromium recovery in diets and feces, and fecal recovery of dietary chromium used as an indicator (marker) for determining nutrient digestibilities. This method should provide more reliable estimates of nutrient digestibility. Key words: Chromium, digestibility, indicator, minerals, sows

A quantitative approach to inner shell losses

1978 ◽  
Vol 36 (1) ◽  
pp. 526-527 ◽  
Author(s):  
R.D. Leapman ◽  
P. Rez ◽  
D.F. Mayers
Keyword(s):  
Energy Transfer ◽  
Cross Section ◽  
Cross Sections ◽  
Accurate Determination ◽  
Background Intensity ◽  
Core Excitation ◽  
Quantitative Basis ◽  
Cross Section Differential ◽  
Bound Electrons

Microanalysis by EELS has been developing rapidly and though the general form of the spectrum is now understood there is a need to put the technique on a more quantitative basis (1,2). Certain aspects important for microanalysis include: (i) accurate determination of the partial cross sections, σx(α,ΔE) for core excitation when scattering lies inside collection angle a and energy range ΔE above the edge, (ii) behavior of the background intensity due to excitation of less strongly bound electrons, necessary for extrapolation beneath the signal of interest, (iii) departures from the simple hydrogenic K-edge seen in L and M losses, effecting σx and complicating microanalysis. Such problems might be approached empirically but here we describe how computation can elucidate the spectrum shape.The inelastic cross section differential with respect to energy transfer E and momentum transfer q for electrons of energy E0 and velocity v can be written as

Fast calibration of CBED patterns for quantitative analysis

1993 ◽  
Vol 51 ◽  
pp. 674-675
Author(s):  
M.A. Gribelyuk ◽  
M. Rühle
Keyword(s):  
Reciprocal Lattice ◽  
Accurate Determination ◽  
Incident Beam ◽  
Crystal Thickness ◽  
Structure Model ◽  
Beam Direction ◽  
Transmitted Beam ◽  
Reciprocal Vector ◽  
On Line

A new method is suggested for the accurate determination of the incident beam direction K, crystal thickness t and the coordinates of the basic reciprocal lattice vectors V1 and V2 (Fig. 1) of the ZOLZ plans in pixels of the digitized 2-D CBED pattern. For a given structure model and some estimated values Vest and Kest of some point O in the CBED pattern a set of line scans AkBk is chosen so that all the scans are located within CBED disks.The points on line scans AkBk are conjugate to those on A0B0 since they are shifted by the reciprocal vector gk with respect to each other. As many conjugate scans are considered as CBED disks fall into the energy filtered region of the experimental pattern. Electron intensities of the transmitted beam I0 and diffracted beams Igk for all points on conjugate scans are found as a function of crystal thickness t on the basis of the full dynamical calculation.

Computer-Assisted High-Re Solution TEM

1990 ◽  
Vol 48 (1) ◽  
pp. 162-163
Author(s):  
F.A. Ponce ◽  
H. Hikashi
Keyword(s):  
Signal To Noise Ratio ◽  
Accurate Determination ◽  
Computer Software ◽  
Video Camera ◽  
Image Contrast ◽  
Objective Lens ◽  
Computer Assisted ◽  
Optical Parameters ◽  
Astigmatism Correction

The determination of the atomic positions from HRTEM micrographs is only possible if the optical parameters are known to a certain accuracy, and reliable through-focus series are available to match the experimental images with calculated images of possible atomic models. The main limitation in interpreting images at the atomic level is the knowledge of the optical parameters such as beam alignment, astigmatism correction and defocus value. Under ordinary conditions, the uncertainty in these values is sufficiently large to prevent the accurate determination of the atomic positions. Therefore, in order to achieve the resolution power of the microscope (under 0.2nm) it is necessary to take extraordinary measures. The use of on line computers has been proposed [e.g.: 2-5] and used with certain amount of success.We have built a system that can perform operations in the range of one frame stored and analyzed per second. A schematic diagram of the system is shown in figure 1. A JEOL 4000EX microscope equipped with an external computer interface is directly linked to a SUN-3 computer. All electrical parameters in the microscope can be changed via this interface by the use of a set of commands. The image is received from a video camera. A commercial image processor improves the signal-to-noise ratio by recursively averaging with a time constant, usually set at 0.25 sec. The computer software is based on a multi-window system and is entirely mouse-driven. All operations can be performed by clicking the mouse on the appropiate windows and buttons. This capability leads to extreme friendliness, ease of operation, and high operator speeds. Image analysis can be done in various ways. Here, we have measured the image contrast and used it to optimize certain parameters. The system is designed to have instant access to: (a) x- and y- alignment coils, (b) x- and y- astigmatism correction coils, and (c) objective lens current. The algorithm is shown in figure 2. Figure 3 shows an example taken from a thin CdTe crystal. The image contrast is displayed for changing objective lens current (defocus value). The display is calibrated in angstroms. Images are stored on the disk and are accessible by clicking the data points in the graph. Some of the frame-store images are displayed in Fig. 4.

DETERMINATION OF AFTER-RIPENING PERIOD AND HORMONAL RESPONSE OF OROBANCHE SOLMSII C.D. CLARKE SEEDS

1970 ◽  
Vol 11 (1) ◽  
Author(s):  
A. Bista ◽  
G. B. Khattri ◽  
B. D. Acharya ◽  
S. C. Srivastava
Keyword(s):  
Growth Hormone ◽  
Seed Germination ◽  
Key Words ◽  
Incubation Period ◽  
Seed Set ◽  
Summer Season ◽  
Conditioning Period ◽  
Root Parasite ◽  
One Year

To find out the ability of Orobanche seeds to germinate immediately after seed set, seeds were germinated periodically at an interval of three months for one year in GR24. Some Orobanche seeds were capable of germination immediately after seed set but most required about nine months as after ripening or incubation period to be able to germinate. The phenomenon of after ripening in Orobanche seeds could be taken as an ecological measure to dormant over following unfavorable wet summer season. The growth hormone studies on Orobanche seed germination have shown that GA3 at a concentration of 100 ppm substantially enhanced seed germination when applied during pre-conditioning period. NAA showed some stimulatory effect at 0.5 - 1.0 ppm when applied during post-conditioning period but the hormone if applied during pre-conditioning period inhibited the germination. Kinetin failed to stimulate the germination at all the concentrations tested. Key words: Germination, root-parasite, hormone. Ecoprint Vol.11(1) 2004.

LYCOPENE POWDER PRODUCING FROM GAC FRUIT TOWARDS APPLICATIONS IN NUTRACEUTICAL AND COSMETICS

2016 ◽  
pp. 51-56
Author(s):  
Thi Le Thuy Nguyen ◽  
Thanh Sinh Do ◽  
Thi Hoa Tran
Keyword(s):  
Key Words ◽  
Propylene Glycol ◽  
Mass Production ◽  
Toxic Substances ◽  
High Concentration ◽  
Concentration Determination ◽  
Modified Method ◽  
Β Carotene ◽  
Key Words Carotenoids

Backgroud: Gac is a fruit containing many antioxidants, especially lycopene, with high concentration. However the variety and value of products from gac are limited. We introduce a modified method to produce lycopene and others carotenoids from gac oil towards available and safe applications in nutraceutical and cosmetics. Materials and method: We study the extraction with different parameters and limit at the saponification of gac oil using less toxic substances such as ethanol, propylene glycol, postasium hydroxide and sodium chlorid. Results: Concentrations of lycopene and β-carotene determined silmutaneously by UVVis spectrophotometer present that the efficiency reaches 65.07% as 20 g of gac oil is saponified with 8 g KOH 12 mol/L in 120 mins. The purity of product is 89.02%. Conclusions: This process could minimize toxic residue in the powder after the precipitation, filtration and washing. Besides, the method is stable and applicable to the mass production. Key words: Carotenoids, Lycopene, safe extraction, UV Vis silmutaneous concentration determination

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