High-tension Voltage Research Articles

Design aspects of high voltage transmission line

The transmission lines are very important in the transmitted of electrical power, and the process of selecting the voltage of the line is an important task in the design and implementation process. The process of transferring electrical power from one side then onto the next place for long away. While maintaining the percentage regulation within the permissible limits is an important problem in the transfer of energy. In electrical transmission line there are important elements are resistance, inductance and capacitance. The purpose of this paper is to study and calculate economic high-tension voltage and selection of overhead line conductor ACSR.

Study of an accurate electronic power measurement technique using modified current transformer and potential transformer

In high tension power measurement, potential transformer (PT) and current transformer (CT) are used in order to reduce high tension voltage and current, respectively. But both PT and CT suffer from ratio error and phase angle error, which may produce severe error in power measurement. In the present paper, modified designs of PT and CT are combined to develop an electronic power measurement circuit in order to reduce the measurement errors. The modified PT and CT have reduced phase angle error and ratio error. In the power measurement circuit, the instantaneous product of the outputs of these PT and CT is determined by using a simple light emitting diode (LED)-light dependent register (LDR) or LED-LDR-based product circuit. The operation of the proto type power measurement unit designed in the present work has been experimentally tested and the measured outputs are compared with the readings of laboratory standard wattmeter. The experimental results are reported in the paper. Very good linear characteristics are observed.

Fluorescence detected linear dichroism spectroscopy: A selective and sensitive probe for fluorophores in flow-oriented systems.

Fluorescence detection typically enhances sensitivity and selectivity for fluorescent analytes. The potential for combining fluorescence detection with flow orientation of the sample in the normal configuration of linear dichroism experiments is explored in this work by measuring the fluorescence emitted from flow-orientated DNA-bound ligands and M13 bacteriophage. Data for ethidium bromide, Hoechst 33258, and 4,6-diamidino-2-phenyindole are presented. The theoretical basis of the technique is also presented for instruments running in both the fixed direct-current mode, which is the normal operation mode of circular dichroism spectropolarimeters, and also in fixed high-tension voltage mode. The role of the stray light reaching the detector that results in a spectral shape in fixed direct current mode that resembles the shape of a linear dichroism spectrum, rather than the expected reduced linear dichroism, is also explored.

Thermal-aggregation suppression of proteins by a structured PEG analogue: Importance of denaturation temperature for effective aggregation suppression

Development of protein stabilizing reagents, that suppress aggregation and assist refolding, is an important issue in biochemical technology related with the synthesis and preservation of therapeutic or other functional proteins. In the precedent research, we have developed a structured poly(ethylene glycol) (PEG) analogue with triangular geometry, which turns into a dehydrated state above ca. 60°C. Focusing on this rather lower dehydration temperature than that of conventional linear PEGs, a capability of the triangle-PEG to stabilize proteins under thermal stimuli was studied for citrate synthase, carbonic anhydrase, lysozyme and phospholipase. Variable temperature high-tension voltage and circular dichroism spectroscopic studies on the mixtures of these proteins and the triangle-PEG showed that the triangle-PEG stabilizes carbonic anhydrase, lysozyme and phospholipase that exhibit denaturation temperatures higher than 60°C, while substantially no stabilization was observed for citrate synthase that denatures below 60°C. Hence, the dehydrated triangle-PEG likely interacts with partially unfolded proteins through the hydrophobic interaction to suppress protein aggregation.

Modeling, Characterizing, and Accommodating Static Birefringence in Circular and Linear Dichroism Spectroscopy

Nearly all circular dichroism (CD) and linear dichroism (LD) spectrometers use a photoelastic modulator (PEM) in which an optical element is stressed using a high-tension voltage (HT) signal to induce birefringence. The birefringence consequently produces a phase difference between perpendicular polarization states of light passing through the PEM that is appropriate to CD or LD measurements. However, even without external stress (i.e., at zero HT) the PEM exhibits an inherent static birefringence. This article discusses the characterization of the static birefringence inherent to a PEM and its effect on the measurement of CD and LD, as well as the development and implementation of a novel model that accommodates for the presence of static birefringence. The model is validated with CD and LD experiments using purely chiral or linearly structured molecules (camphorsulfonic acid and chrysazin).

Circular dichroism studies of subtilisin Carlsberg immobilised on micron sized silica particles

Immobilised enzymes are widely used in industry, but the reasons for loss of activity of such biocatalysts are usually not known. We have used circular dichroism (CD) to investigate the structure of one such system, i.e., subtilisin Carlsberg (SC) immobilised on silica gel particles (60 μm). A number of technical problems have to be overcome in order to obtain appropriate data from which conclusions can be drawn. A rotating cell holder has been developed to avoid sedimentation of the silica particles during the collection of spectra. By moving the cell holder as close as possible to the detector window, the effects of differential scattering can be minimised. However, the effects of absorption flattening limit the extent to which reliable quantitative information on secondary structure content can be obtained from far UV CD studies. We have used an empirical approach based on absorbance units derived from the high-tension voltage to correct for absorption flattening effects. After applying the correction there was satisfactory agreement with the solution spectra. Comparison of the fresh and used (inactive) SC-silica gel spectra in organic media reveals substantial change in the secondary structure. Additional evidence for loss of native conformation is provided by the significant decrease in the near UV CD spectrum. These results for the first time clearly demonstrate the origin of enzyme instability in the immobilised state.

A new method for fibrous protein analysis illustrated by application to tubulin microtubule polymerisation and depolymerisation

A thermostatted micro volume Couette cell has been designed to enable linear dichroism (LD) data to be collected at a range of temperatures. The cell is a development of the traditional Couette flow LD cell and includes the recent development of micro-volume LD (20-40 microL) coupled with the addition of a heating element, temperature probe and controller. This new micro volume Couette LD cell opens the way not only to the LD analysis of systems where sample volume is critical, but also for the LD analysis of temperature sensitive samples. The polymerization of the microtubule protein tubulin has been followed in a range of different conditions using the thermostatted micro volume Couette LD cell. The focusing lenses on the cell, which are required for the microvolume cell, have the side benefit of significantly reducing the light-scattering artifacts caused by the large size of tubulin microtubules. It is now possible to monitor real-time polymerization and depolymerization kinetics, and any structural rearrangements of chromophores within the polymer. In the case of tubulin, the LD spectra revealed a greater change in the orientation of tryptophan residues at approximately 290 nm during polymerization compared to other contributing chromophores-guanine, phenylalanine, and tyrosine. The improvements in instrumental design have also allowed LD spectra of tubulin to be collected down to approximately 230 nm (previous data have only been available from the near UV region), which means that some indication of protein backbone-orientation changes are now available. It was observed during this work that apparent LD intensity maxima are in fact artifacts when the high-tension voltage is high. The onset of such artifacts has been observed at much lower voltages with light-scattering fibrous proteins (including tubulin) than with nonscattering samples. Therefore, caution must be used when interpreting LD data collected with medium to high photomultiplier tube voltages.

Correlation of renal complications with extent and progression of tissue damage in electrical burns

ABSTRACTElectrical injuries due to high-tension voltage (>1000 volts) cause destruction at the point of contact with massive necrosis of deeper structures such as muscles, vessels and nerves. Rhabdomyolysis due to massive breakdown of skeletal muscles may lead to acute renal failure secondary to myoglobinuria. The study was undertaken to observe the correlation of renal complications with extent and progression of tissue damage in high-tension voltage electrical burns. Renal biochemical parameters as predictors of acute renal failure were also studied. Thirty two patients of high tension voltage electrical burn injuries presenting during one year period 1-1-2001 to 31-12-2001 were studied. Low-tension voltage electrical injuries (< 1000 volts) mimic thermal burns were excluded from the study. The electrical wound assessment and the renal biochemical parameters were done daily for the first seven days and then on alternate days for another seven days. Assessment of progression of wounds and correlation with the renal biochemical parameters was done. Patients who died following electrical burns were subjected to autopsy and histopathological examination of both kidneys. Out of the thirty-two patients, six (18.75%) went into acute renal failure. Five out of these six patients died because of renal failure (mortality rate 83.33%). There was definite progression of electric burn wounds. There was no correlation between progression of electrical burn wounds and acute renal failure. Serum creatinine was found to be the most important biochemical parameter as a prognostic indicator of acute renal failure.

プラズマ援用による微粒子分級法の開発

A Plasma-assisted fine particle classification method has been developed by using a positive column of glow-discharge in the Geisler tube. The particles are charged in plasma, in which their surface is covered with the sheath made of double layers of negative and positive ions. Charged particles fly to the positive electrode under high tension voltage. The flying mode, however, is influenced by the gravity and the collision of the plasma ions to the flying particles. A newlydeveloped classification setup is made with three main parts -the Geisler tube, a powder supplier and an evacuation system. The fine powders such as those of alumina, sillica and silicon carbide, were classified under the condition of DC voltage of 2kV and the tube current of 1.5mA at 1Torr. It was found from the experiments that the coaser particles fell down near the inlet of the powder supplier, but the finer ones flew apart from it. The classification characteristics may be determined by the charging mode and the electric property of particles.

An ultra-sensitive high-tension electrostatic indicating voltmeter

An instrument is described which indicates a change of 1 part in 1000 in a voltage of 45 kV by the shift of a spot of light through several millimetres, and which takes up its reading in under 2 sec. Its repeatability is guaranteed by the use of a quartz torsional control; and by supporting the moving part at both ends the disturbing effect of vibrations is eliminated. It is completely self-shielded from electrostatic disturbance, is small and not difficult to construct. It is therefore an indicating instrument specialized for use when a high-tension voltage has to be maintained accurately constant, as, for example, when carrying out X-ray ionization measurements. It is not suitable for absolute determinations of voltage.

The ionic wind voltmeter and thermo-electrostatic relay

The electric wind observed in the neighbourhood of a highly charged point in air is caused by the repulsion of ions produced at the surface of the point by the intense field there. In their movement the ions collide with uncharged molecules of air, thus giving to them velocity and, in effect, causing a wind from the point. When the field is alternating this wind has two components, a steady stream of air and a movement of alternation in synchronism with the field. The effect is observed at both high-tension and earthed poles. By enclosing the latter in an insulating vessel and using as the electrode a bent wire with suitable anti-corona shields, the wire is found to be cooled by the alternating component of the wind, and this cooling to be remarkably steady. The effect was investigated by varying the temperature of wire, the gas pressure in the enclosure, the nature of the gas, and the dimensions of the field, and the law for each of these variants is given. An instrument based on this action, termed an “ionic wind voltmeter,” was designed to indicate the voltage of any system above a few thousand volts by making the earthed electrode part of a hot-wire bridge. The balance of the bridge is disturbed when the field is applied, and the out-of-balance bridge voltage is a measure of the high-tension voltage, which can be observed at any distance. An indoor form is made to indicate up to 300 kV, an outdoor form up to 132 kV, and portable forms from 3 kV to 150 kV for general testing and X-ray work.

A wireless broadcasting transmitting station for dual programme service

The B.B.C. Regional Scheme involves the construction of number of twin wireless transmitting stations, each capable of radiating simultaneously two programmes on different wavelengths, and each at a power of 50 kW in the aerial. This paper describes the first of these twin transmitters, erected at Brookmans Park, Hertfordshire, to serve London and the Home Counties.The paper deals with the considerations underlying the choice of sites for such broadcasting stations, the type of power supply adopted, and the factors contributing to reliability in operation, as well as with the wireless transmitters themselves. Detailed considerations underlying the design of such transmitters have been avoided in the anticipation that they will form the subject of a further paper; but, nevertheless, some information in regard to the essential and major points in their design is contained herein.The paper deals further with the general station lay-out, the building and the auxiliary services, as well as with lowfrequency apparatus for supplying modulation to the transmitter and apparatus for testing and monitoring purposes, etc.Of particular interest is the use of high-tension directcurrent machines at this station for the production of hightension voltage for anode supply to the main power valves. The type of generator developed especially for this work is considered in some detail.

A wireless broadcasting transmitting station for dual programme service

The B.B.C. Regional Scheme involves the construction of a number of twin wireless transmitting stations, each capable of radiating simultaneously two programmes on different wavelengths, and each at a power of 50 kW in the aerial. This paper describes the first of these twin transmitters, erected at Brookmans Park, Hertfordshire, to serve London and the Home Counties.The paper deals with the considerations underlying the choice of sites for such broadcasting stations, the type of power supply adopted, and the factors contributing to reliability in operation, as well as with the wireless transmitters themselves. Detailed considerations underlying the design of such transmitters have been avoided in the anticipation that they will form the subject of a further paper; but, nevertheless, some information in regard to the essential and major points in their design is contained herein.The paper deals further with the general station lay-out, the building and the auxiliary services, as well as with low-frequency apparatus for supplying modulation to the transmitter and apparatus for testing and monitoring purposes, etc.Of particular interest is the use of high-tension direct-current machines at this station for the production of high-tension voltage for anode supply to the main power valves. The type of generator developed especially for this work is considered in some detail.

The voltmeter coil in testing transformers

FOR EXACT determination of the high-tension voltage in testing transformers, an auxiliary winding of few turns placed on the same core and connected to an accurate voltmeter has been used with success.