scholarly journals ELECTRICAL POTENTIAL BETWEEN NON-PARALLEL FLAT ELECTRODES – SIMULATION OF A CELL USED WITH TOMATO

Anales AFA ◽  
2021 ◽  
Vol 32 (2) ◽  
pp. 43-47
Author(s):  
A. Hemsy ◽  
Keyword(s):  
Laplace Equation ◽  
Finite Differences ◽  
Electrical Potential ◽  
Dielectric Measurements ◽  
Electrode Separation ◽  
Numerical Iteration ◽  
A Cell ◽  
Fortran Language ◽  
Made In

The equipotential lines of the field generated by the cell used in dielectric measurements of whole fruit tomato are plotted. This cell consists of two inclined electrodes, at inverse potentials, and is an adaptation made in the Dielectric Laboratory of the cell used by Varlan-Sansen. To obtain the graphs, the Laplace equation was solved by finite differences and a program in Fortran language was written, which performs the calculations by numerical iteration. The field generated by the cell at different electrode separation distances was analyzed.

Mass Spectrometry Techniques: Principles and Practices for Quantitative Proteomics

2020 ◽  
Vol 21 ◽  
Author(s):  
Rocco J. Rotello ◽  
Timothy D. Veenstra
Keyword(s):  
Mass Spectrometry ◽  
Quantitative Proteomics ◽  
Protein Identification ◽  
Dynamic Nature ◽  
Complete Coverage ◽  
The Past ◽  
Proteome Level ◽  
A Cell ◽  
Quantitative Changes ◽  
Made In

: In the current omics-age of research, major developments have been made in technologies that attempt to survey the entire repertoire of genes, transcripts, proteins, and metabolites present within a cell. While genomics has led to a dramatic increase in our understanding of such things as disease morphology and how organisms respond to medications, it is critical to obtain information at the proteome level since proteins carry out most of the functions within the cell. The primary tool for obtaining proteome-wide information on proteins within the cell is mass spectrometry (MS). While it has historically been associated with the protein identification, developments over the past couple of decades have made MS a robust technology for protein quantitation as well. Identifying quantitative changes in proteomes is complicated by its dynamic nature and the inability of any technique to guarantee complete coverage of every protein within a proteome sample. Fortunately, the combined development of sample preparation and MS methods have made it capable to quantitatively compare many thousands of proteins obtained from cells and organisms.

Assessing the differentiation state of cultured bovine urothelial cells: elevated synthesis of stratification-related K5 and K6 keratins and persistent expression of uroplakin I

1990 ◽  
Vol 97 (3) ◽  
pp. 419-432 ◽  
Author(s):  
B. Surya ◽  
J. Yu ◽  
M. Manabe ◽  
T.T. Sun
Keyword(s):  
Feeder Cells ◽  
Serum Free Medium ◽  
Urothelial Cells ◽  
Significant Progress ◽  
Protein Subunit ◽  
A Cell ◽  
Umbrella Cells ◽  
Normal Urothelium ◽  
Made In ◽  
Biochemical Differentiation

Although significant progress has recently been made in culturing mammalian urothelial cells, relatively little is known about their biochemical differentiation. In this paper, we assessed the differentiation state of cultured bovine urothelial cells by analyzing their keratins and a cell surface marker, uroplakin I. Urothelial cells were serially cultured either in a serum-free medium, or in a serum-containing medium in the presence of 3T3 feeder cells, with similar results. Despite their stratified appearance, both normal urothelium and cultured urothelial cells synthesize mainly K8, K18 and K19, keratins that are typically seen in simple epithelia. However, cultured urothelial cells synthesize a greatly increased amount of K5 and K6 keratins, which are usually expressed by stratified epithelia but present only in trace amounts in normal urothelium. These data indicate that, as far as keratin synthesis is concerned, cultured urothelial cells undergo an altered pattern of differentiation towards a more ‘stratified phenotype’; this unusual finding has interesting implications for urothelial evolution. In the meantime, many superficial cells in cultured urothelial colonies make uroplakin I, a 27 × 10(3) Mr protein subunit of the asymmetrical unit membrane (AUM) characteristic of urothelial (superficial) umbrella cells. These results indicate that cultured urothelial cells undergo, at least in part, AUM biogenesis. Cultured urothelial cells thus provide a useful experimental model system for studying certain early steps of AUM formation.

scholarly journals Compartment-Restricted Biotinylation Reveals Novel Features of Prion Protein Metabolism in Vivo

2010 ◽  
Vol 21 (24) ◽  
pp. 4325-4337 ◽  
Author(s):  
Amy B. Emerman ◽  
Zai-Rong Zhang ◽  
Oishee Chakrabarti ◽  
Ramanujan S. Hegde
Keyword(s):  
Cell Surface ◽  
Prion Protein ◽  
Protein Metabolism ◽  
Selective Detection ◽  
Wild Type ◽  
Selective Labeling ◽  
A Cell ◽  
Cellular Compartments ◽  
Made In

Proteins are often made in more than one form, with alternate versions sometimes residing in different cellular compartments than the primary species. The mammalian prion protein (PrP), a cell surface GPI-anchored protein, is a particularly noteworthy example for which minor cytosolic and transmembrane forms have been implicated in disease pathogenesis. To study these minor species, we used a selective labeling strategy in which spatially restricted expression of a biotinylating enzyme was combined with asymmetric engineering of the cognate acceptor sequence into PrP. Using this method, we could show that even wild-type PrP generates small amounts of the CtmPrP transmembrane form. Selective detection of CtmPrP allowed us to reveal its N-terminal processing, long half-life, residence in both intracellular and cell surface locations, and eventual degradation in the lysosome. Surprisingly, some human disease-causing mutants in PrP selectively stabilized CtmPrP, revealing a previously unanticipated mechanism of CtmPrP up-regulation that may contribute to disease. Thus, spatiotemporal tagging has uncovered novel aspects of normal and mutant PrP metabolism and should be readily applicable to the analysis of minor topologic isoforms of other proteins.

Combustion-Drive Tests

1963 ◽  
Vol 3 (01) ◽  
pp. 53-58 ◽  
Author(s):  
W.E. Showalter
Keyword(s):  
Oil Recovery ◽  
Test Cell ◽  
Test Method ◽  
Silica Sand ◽  
Operating Pressure ◽  
Oil Sand ◽  
Recovery Method ◽  
A Cell ◽  
Made In

SHOWALTER, W.E., UNION OIL CO. OF CALIFORNIA, BREA, CALIF. Abstract This paper discusses some of the results of combustion-drive tests which were made in a test cell using a sand bed 10 in. in diameter × 10-ft long. The test method is illustrated and described.The relationship between the API gravity of the in situ oil and the amount of air required for combustion drive is discussed n detail. Other things constant, the air requirement for combustion drive increases as the API gravity of the in situ oil decreases. If the test results apply to actual reservoirs, the lowest-priced oils may cost the most to recover by this method.Information is shown which indicates that the effect of pressure on the amount of hydrocarbon burned is not large. A method of predicting air requirements from the API gravity of the in situ oil is presented. Introduction Combustion drive is the term used to identify the process of interstitial or in situ burning as an oil recovery method. Part of the in situ oil is burned to generate the energy needed to produce the remainder of the oil. Combustion drive as an oil recovery mechanism remains an economic uncertainty in spite of all the work that has been done by the industry in both laboratory and field. This paper will show some of the results of tests which were made in a test cell for the purpose of studying the nature of the combustion-drive process. It will present data which indicate that the API gravity of the in situ oil is a significant indicator of the amount of air required to drive a burning front through oil sand. Air requirement varies inversely as the API gravity of the in situ oil. EXPERIMENTAL The tests were performed in a cell which utilized a cylindrical sand section 10 in. in diameter × 10-ft long. The thin-walled metal pipe which held the sand was wound with twenty external electrical resistance heaters which, by means of an automatic controller, maintained adjacent sections of the wall of the pipe at temperatures equal to the temperatures of the contained sand. Each heater covered 6 linear in. of the pipe. By this means lateral heat loss from the sand section was minimized, thereby causing the sand section to simulate more closely a horizontal increment of a combustion-drive reservoir.Fig. 1 shows a schematic diagram of the test assembly.Thermocouplestomeasurethetemperature in the sand were located every 6 in. along the length of the sand section. The pipe containing the sand was enclosed in a cell designed for an operating pressure of 500 psig. The inlet air pressure was controlled at the inlet, and the gas flow rate was controlled and measured at the outlet of the cell.The oil sand used for the tests was prepared by mixing first water and then oil with the non-consolidated sand using a closed mixer similar to a cement mixer. Table 1 shows a screen analysis of the sand. Ninety percent of the sand was 100 mesh or finer. This sand was a mixture of 80 per cent No. 120 Nevada White Sand and 20 per cent Tennessee Hi-Fusion Moulding Sand No. 3. The Nevada sand was a clean silica sand. SPEJ P. 53^

Patch clamp technique: Review of the current state of the art and potential contributions from nanoengineering

2008 ◽  
Vol 222 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Y Zhao ◽  
S Inayat ◽  
D A Dikin ◽  
J H Singer ◽  
R S Ruoff ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Patch Clamp ◽  
Ionic Currents ◽  
Low Noise ◽  
Patch Clamp Technique ◽  
Clamp Technique ◽  
Current State ◽  
A Cell ◽  
Patch Clamp Method ◽  
Made In

The patch clamp technique permits high-resolution recording of the ionic currents flowing through a cell's plasma membrane. In different configurations, this technique has allowed experimenters to record and manipulate the currents that flow either through single ion channels or those that flow across the whole plasma membrane. Unfortunately, the conventional patch clamp method is laborious, requiring the careful fabrication of electrodes, skillful manipulation of the patch pipette towards a cell, and the clever design of electronics and apparatus to allow low-noise recordings. Advances in microfabrication offer promising technologies for high-throughput patch clamp recordings, particularly suitable for drug screening. This paper provides a review of the advances that have been made in the patch clamp technique over the years and considers where application of nanotechnology might provide significant contributions in the future.

scholarly journals Digital possibilities of the reconstruction of machine parts

2019 ◽  
Vol 254 ◽  
pp. 01007
Author(s):  
Piotr Paszta
Keyword(s):  
Cell Phone ◽  
Spatial Modelling ◽  
Continuous Development ◽  
3D Scanner ◽  
Equipment Manufacturing ◽  
A Cell ◽  
3D Scanners ◽  
Machine Parts ◽  
The Creation ◽  
Made In

A rapid and continuous development of the machinery and equipment manufacturing capabilities is currently going on. Using CAx programs, complex elements can be made in a straightforward and very fast manner. The creation and use of spatial scanners, photogrammetric methods and spatial modelling is intensively developing, too. A complete object can be produced without the help of tactile methods, using professional 3D scanners, scanners of one's own construction, a camera, or even a cell phone with an in-built camera. The article has described the capabilities of a 3D scanner, verified its accuracy, and has also discussed the capabilities of photogrammetric methods to reconstruct machine parts.

Borehole resistivity curves near spheroidal masses

Geophysics ◽  
1980 ◽  
Vol 45 (10) ◽  
pp. 1513-1522 ◽  
Author(s):  
T. L. Dobecki
Keyword(s):  
Electrical Resistivity ◽  
Coal Gasification ◽  
Random Noise ◽  
Electrical Potential ◽  
The Body ◽  
Process Time ◽  
Prolate Spheroidal ◽  
Cross Sectional ◽  
Oblate Body ◽  
Made In

Modeling of in situ energy extraction processes (e.g., coal gasification and oil shale retorting) has been examined by assuming the affected zones may be described by oblate or prolate spheroids of lowered electrical resistivity. The purpose of the model study is to determine if such subsurface bodies may be monitored and defined by electrical resistivity measurements made in boreholes away from the reaction zone. Solutions of the Laplace equation in (1) oblate and (2) prolate spheroidal coordinate systems enable theoretical determination of the electrical potential distribution as would be measured in a borehole near an anomalous body of oblate or prolate shape. The body is assumed to be enclosed within an infinite, homogeneous mass. Normal (pole‐pole) type curves of (1) electrical resistivity for various electrode spacings (sounding curves) and (2) electrical resistivity for various positions in the borehole (vertical profiling) are developed for both oblate and prolate spheroidal models using spheroids of increasing size as a sensitivity parameter. Modeling results verify that an oblate body of the same cross‐sectional shape as a prolate body produces the larger anomaly. For the various size and resistivity parameters specified in this study, deviations from the homogeneous case (i.e., no spheroid) range from 3 percent for the smallest oblate and prolate bodies up to 60 percent for the largest modeled oblate body. If a ±5 percent uncertainty because of instrumentation, field technique, or random noise may be assumed, this implies a lower limit to the size of a detectable body. On this basis, the smaller spheroids of this study would not be detectable. However, both sounding and profiling type measurements offer promise as effective monitoring tools, and, if repeated over the period of process time, may enable process growth estimates. Further, because the oblate case is independent of azimuth while the prolate is not, measurements made in a series of borings surrounding the process center may describe the shape tendency (oblate versus prolate) of the process and determine directivity (azimuth of prolate major axis) of the process if existent.

A cell for dielectric measurements in fluorinated atmospheres

1981 ◽  
Vol 19 (1) ◽  
pp. 61-66 ◽  
Author(s):  
A. Tressaud ◽  
L. Lozano ◽  
J. Ravez
Keyword(s):  
Dielectric Measurements ◽  
A Cell

scholarly journals Development of a Technique and Investigation of Capacitance Characteristics of Electrode Materials for Supercapacitors Based on Nitrogen-Doped Carbon Nanotubes

2017 ◽  
Vol 19 (3) ◽  
pp. 201 ◽  
Author(s):  
G. Simenyuk ◽  
A. Puzynin ◽  
O. Podyacheva ◽  
A. Salnikov ◽  
Yu. Zakharov ◽  
...  
Keyword(s):  
Carbon Nanotubes ◽  
Electrode Materials ◽  
Acid Electrolyte ◽  
Nitrogen Doped ◽  
Electrochemical Processes ◽  
Electrode Cell ◽  
A Cell ◽  
Capacitance Characteristics ◽  
Nitrogen Doped Carbon ◽  
Made In

Carbon nanotubes are widely employed as catalyst supports and electrode materials. In our earlier studies, capacitance characteristics of carbon nanotubes (CNTs) and nitrogen-doped carbon nanotubes (N-CNTs) were measured. Voltammetric curves obtained for nitrogen-doped nanotubes in an acid electrolyte showed pseudocapacitance peaks that were caused by electrochemical processes involving nitrogen-containing functional groups. In this study, measurements were made in a two-electrode cell of a supercapacitor with a hydrophilic polypropylene PORP-A1 film serving as a separator in alkaline (6 M KOH solution) and acid (1 M H2SO4 solution) electrolytes using a PARSTAT 4000 potentiostat/galvanostat. A technique was developed to estimate the contribution of electrical double layer (EDL) by subtracting pseudocapacitance from total capacitance of a cell using the Origin 9 software. The contribution of EDL and pseudocapacitance to the capacitance of supercapacitor cells was estimated. The highest capacitance of an electrode material equal to 97.2 F/g (including the EDL capacitance of 65 F/g) was reached for nanotubes doped with 8.5% of nitrogen in an acid electrolyte at a potential scanning rate of 10 mV/s.

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