scholarly journals Hydrate and Wax Prevention in Flowlines by Electrical Heating

2000 ◽  
Author(s):  
Jens Kristian Lervik ◽  
Harald Kulbotten ◽  
Gunnar Klevjer ◽  
Øyvind Iversen
Keyword(s):  
Power Supply ◽  
Hydrate Formation ◽  
Magnetic Characteristic ◽  
Heating System ◽  
Electrical Heating ◽  
Oil Companies ◽  
Direct Heating ◽  
The North ◽  
Wide Range ◽  
The Difference

Traditional chemical treatment methods have considerable operation costs and represent a risk to the environment. Since 1987 Norwegian oil companies have been investigating alternative electrical heating methods for prevention of hydrate and wax plugs. A joint industry project ‘Concept Verification – Direct Heating of Oil & Gas Pipelines’ was initiated in 1996 and terminated in October 1999. During this work an electrical heating system was proved to be feasible on several fields in the North Sea. It will be installed on 7 flowlines of 13% Chromium (Crl3) with lengths between 6 km and 16 km. Electrical heating is used to maintain or raise the thermally insulated steel pipe temperature above the critical value for hydrate formation (typically 15–25 °C) or wax formation (typically 20–40°C). A single-phase power supply for the heating system is based on commercial components and connected to the platform power supply. The qualification work for the direct heating system has included full scale testing for single and parallel pipes, end termination at the template, bypass of a template and aspects concerning corrosion control. The rating of the system is dependent on the magnetic and electrical characteristics of the steel material. Such data is not commonly available. Measurements performed during the qualification program confirm that the magnetic characteristic may vary within a wide range for a specific steel quality and that mechanical stress and heat treatment can effect the magnetic characteristic. The difference in magnetic characteristic of individual Crl3 pipes results in variation of the pipe temperature and problems concerning differential pressure during melting. The problem can be handled by dividing the pipeline into a number of sections, each with a limited variation of the magnetic characteristic, thus keeping the temperature for the whole pipeline within acceptable limits. As a part of the pipe specification both electrical and magnetic characteristic should be available. These data can be determined by measuring arrangements in the production line of the mill. Measures to limit the variation of magnetic characteristic should be discussed.

IMPROVING ENERGY EFFICIENCY AND ENERGY SAVING AT THE PURTAZOVSKAYA INDUSTRIAL SITE OF LLC “GAZPROM TRANSGAZ SURGUT”

2021 ◽  
Vol 7 (3) ◽  
pp. 41-52
Author(s):  
Lyudmila B. Polovnikova ◽  
Boris D. Polovnikov
Keyword(s):  
Water Supply ◽  
Power Supply ◽  
Power Supply System ◽  
Western Siberia ◽  
Electrical Heating ◽  
Compressor Station ◽  
The North ◽  
Housing Complex ◽  
Harsh Conditions ◽  
Design Power

This article describes an original engineering solution for the modernization of electrical heating of a water conduit in the harsh conditions of the North of Western Siberia. The novelty of the proposed solution consists in the introduction of additional control of the switching on of the line from the water intake wells to the water filtration station of the rotational housing complex of the compressor station of the Purtazovskaya industrial site of LLC “Gazprom Transgaz Surgut”. The proposed rationalization solution has no analogues in the field electrical heating of the water conduit. The relevance of the proposed innovation determines its significance and relevance in the harsh conditions of the North, its application reduces labor costs and determines the economic efficiency and safe transportation of the existing water supply source to the harsh conditions of the North of Western Siberia at the Purtazovskaya compressor station of the Novo-Urengoysky linear production department of the main gas pipelines of LLC “Gazprom Transgaz Surgut”. The purpose of the study was to propose a rational solution for changing the design power supply system for heating lines for water supply pipelines of a rotational housing complex. The objectives of the study included: analysis of the shortcomings of the design power supply system; proposal of a methodology for modernization of the control system for the operation of electric heating lines; reconstruction of the electrical heating system. A feature of the innovation is the complete autonomy of the compressor station. Electricity is generated by its own power plant. The heat is supplied by its own boiler room. The source of water supply for household drinking and industrial fire-fighting needs is the existing and functioning water intake from underground sources (artesian wells). The only method of industrial electrical heating of pipelines up to thirty kilometers long, which does not require an accompanying network, is the SKIN system. The research methodology consisted in changing the power supply scheme of heating lines for water supply pipelines and its installation, which made it possible to obtain an up-to-date technical solution for the conditions of the Far North and contributed to an increase in energy efficiency and energy saving.

AN EVALUATION OF THE GRAVITY CONTROL NETWORK IN NORTH AMERICA

Geophysics ◽  
1961 ◽  
Vol 26 (1) ◽  
pp. 57-76 ◽  
Author(s):  
J. C. Behrendt ◽  
G. P. Woollard
Keyword(s):  
North America ◽  
Geodetic Survey ◽  
Control Network ◽  
Mean Values ◽  
The North ◽  
University Of Wisconsin ◽  
Systematic Correction ◽  
Free Air ◽  
Wide Range ◽  
The Difference

Observations with a LaCoste and Romberg geodetic gravimeter having a very low nearly linear drift rate, a high reading precision, and a world wide range were made at approximately three hundred sites in order to check and extend the gravity control network in North America. The sites occupied were mostly at former gravimeter bases located at airports, harbors, universities, and pendulum stations. The instrument was calibrated against the North American standardization range of pendulum measurements from Paso de Cortes, Mexico, to Fairbanks, Alaska, using the weighted mean values of the observations established with the U. S. Coast and Geodetic Survey, Cambridge University (England), and Gulf‐University of Wisconsin pendulum equipment. A statistical evaluation of the precision of the network based on the reoccupations at 40 major control stations gives an estimated standard deviation of 0.08 mgal. The airport network of bases previously reported by Woollard (1958) that was established with high range Worden gravity meters was found to require a systematic correction of 0.3 mgal per 1,000 mgal change because of the difference in calibration standard used. The adjusted values for the forty airport stations reoccupied agree on the average to 0.2 mgal with the results of this study. The reoccupations of the old pendulum observation sites of the U. S. Coast and Goedetic Survey suggest that much of this network is in error by over 3 mgals. Descriptions of sites occupied and the principal facts for position, elevation, observed gravity, and free‐air and Bouguer anomalies are presented.

Comparative Effects of High-Tech Visual Scene Displays and Low-Tech Isolated Picture Symbols on Engagement From Students With Multiple Disabilities

2019 ◽  
Vol 50 (4) ◽  
pp. 693-702 ◽  
Author(s):  
Christine Holyfield ◽  
Sydney Brooks ◽  
Allison Schluterman
Keyword(s):  
Language Learning ◽  
Augmentative And Alternative Communication ◽  
Visual Analysis ◽  
Multiple Disabilities ◽  
Visual Scene ◽  
Future Research ◽  
High Tech ◽  
Single Subject ◽  
Wide Range ◽  
The Difference

Purpose Augmentative and alternative communication (AAC) is an intervention approach that can promote communication and language in children with multiple disabilities who are beginning communicators. While a wide range of AAC technologies are available, little is known about the comparative effects of specific technology options. Given that engagement can be low for beginning communicators with multiple disabilities, the current study provides initial information about the comparative effects of 2 AAC technology options—high-tech visual scene displays (VSDs) and low-tech isolated picture symbols—on engagement. Method Three elementary-age beginning communicators with multiple disabilities participated. The study used a single-subject, alternating treatment design with each technology serving as a condition. Participants interacted with their school speech-language pathologists using each of the 2 technologies across 5 sessions in a block randomized order. Results According to visual analysis and nonoverlap of all pairs calculations, all 3 participants demonstrated more engagement with the high-tech VSDs than the low-tech isolated picture symbols as measured by their seconds of gaze toward each technology option. Despite the difference in engagement observed, there was no clear difference across the 2 conditions in engagement toward the communication partner or use of the AAC. Conclusions Clinicians can consider measuring engagement when evaluating AAC technology options for children with multiple disabilities and should consider evaluating high-tech VSDs as 1 technology option for them. Future research must explore the extent to which differences in engagement to particular AAC technologies result in differences in communication and language learning over time as might be expected.

COMBINATORIAL POLYNOMIALLY COMPUTABLE CHARACTERISTICS OF SUBSTITUTIONS AND THEIR PROPERTIES

2020 ◽  
Vol 7 (2) ◽  
pp. 34-41
Author(s):  
VLADIMIR NIKONOV ◽  
◽  
ANTON ZOBOV ◽  
Keyword(s):  
Mathematical Expectation ◽  
Point Of View ◽  
Small Range ◽  
Computational Point ◽  
Wide Range ◽  
Bijective Function ◽  
The Difference ◽  
Element Base ◽  
Selection Of

The construction and selection of a suitable bijective function, that is, substitution, is now becoming an important applied task, particularly for building block encryption systems. Many articles have suggested using different approaches to determining the quality of substitution, but most of them are highly computationally complex. The solution of this problem will significantly expand the range of methods for constructing and analyzing scheme in information protection systems. The purpose of research is to find easily measurable characteristics of substitutions, allowing to evaluate their quality, and also measures of the proximity of a particular substitutions to a random one, or its distance from it. For this purpose, several characteristics were proposed in this work: difference and polynomial, and their mathematical expectation was found, as well as variance for the difference characteristic. This allows us to make a conclusion about its quality by comparing the result of calculating the characteristic for a particular substitution with the calculated mathematical expectation. From a computational point of view, the thesises of the article are of exceptional interest due to the simplicity of the algorithm for quantifying the quality of bijective function substitutions. By its nature, the operation of calculating the difference characteristic carries out a simple summation of integer terms in a fixed and small range. Such an operation, both in the modern and in the prospective element base, is embedded in the logic of a wide range of functional elements, especially when implementing computational actions in the optical range, or on other carriers related to the field of nanotechnology.

Generalized Heterodyne Configurations for Photo-induced Force Microscopy

2019 ◽  
Author(s):  
Le Wang ◽  
Devon Jakob ◽  
Haomin Wang ◽  
Alexis Apostolos ◽  
Marcos M. Pires ◽  
...  
Keyword(s):  
Spatial Resolution ◽  
Repetition Rate ◽  
Modulation Frequency ◽  
High Harmonic ◽  
Chemical Imaging ◽  
Heterodyne Detection ◽  
Force Microscopy ◽  
Wide Range ◽  
The Difference ◽  
Afm Cantilever

<div>Infrared chemical microscopy through mechanical probing of light-matter interactions by atomic force microscopy (AFM) bypasses the diffraction limit. One increasingly popular technique is photo-induced force microscopy (PiFM), which utilizes the mechanical heterodyne signal detection between cantilever mechanical resonant oscillations and the photo induced force from light-matter interaction. So far, photo induced force microscopy has been operated in only one heterodyne configuration. In this article, we generalize heterodyne configurations of photoinduced force microscopy by introducing two new schemes: harmonic heterodyne detection and sequential heterodyne detection. In harmonic heterodyne detection, the laser repetition rate matches integer fractions of the difference between the two mechanical resonant modes of the AFM cantilever. The high harmonic of the beating from the photothermal expansion mixes with the AFM cantilever oscillation to provide PiFM signal. In sequential heterodyne detection, the combination of the repetition rate of laser pulses and polarization modulation frequency matches the difference between two AFM mechanical modes, leading to detectable PiFM signals. These two generalized heterodyne configurations for photo induced force microscopy deliver new avenues for chemical imaging and broadband spectroscopy at ~10 nm spatial resolution. They are suitable for a wide range of heterogeneous materials across various disciplines: from structured polymer film, polaritonic boron nitride materials, to isolated bacterial peptidoglycan cell walls. The generalized heterodyne configurations introduce flexibility for the implementation of PiFM and related tapping mode AFM-IR, and provide possibilities for additional modulation channel in PiFM for targeted signal extraction with nanoscale spatial resolution.</div>

Dimensionamiento de un horno de fundición por inducción electromagnética y cálculo de los parámetros eléctricos

2019 ◽  
pp. 1-15
Author(s):  
Arnulfo Pérez-Pérez ◽  
Jorge Sergio Téllez-Martínez ◽  
Gregorio Hortelano-Capetillo ◽  
Jesús Israel Barraza-Fierro
Keyword(s):  
Induction Heating ◽  
Power Supply ◽  
Electromagnetic Induction ◽  
Cast Steel ◽  
Electrical Power ◽  
Heating System ◽  
Heating Time ◽  
Ferrous Alloys ◽  
Electromagnetic Induction Heating ◽  
Induction Heating System

In this work, the dimensions of a furnace for melting of ferrous alloys were determined. The furnace has an electromagnetic induction heating system. In addition, the parameters of electrical power supply such as frequency and power were calculated. A 5kg cast steel mass with a density of 7.81 kg / dm3 was proposed. This corresponds to a crucible volume of 0.641 dm3. The frequency was obtained from tables, which take into account the diameter of the crucible, and its value was 1 KHz. The energy consumption was determined with the heat required to bring the steel to the temperature of 1740 K, the energy losses through the walls, bottom and top of the crucible. This value was divided between the heating time (30 minutes) and resulted in a power of 4.5 KW. The development of the calculations shows that the induction heating is an efficient process and allows a fast melting of ferrous alloys.

scholarly journals Carbon Isotope Fractionation during the Formation of CO2 Hydrate and Equilibrium Pressures of 12CO2 and 13CO2 Hydrates

Molecules ◽  
2021 ◽  
Vol 26 (14) ◽  
pp. 4215
Author(s):  
Hiromi Kimura ◽  
Go Fuseya ◽  
Satoshi Takeya ◽  
Akihiro Hachikubo
Keyword(s):  
Carbon Isotope ◽  
Isotope Fractionation ◽  
Small Difference ◽  
Hydrate Formation ◽  
Formation Temperature ◽  
Carbon Isotope Fractionation ◽  
Unit Cell Size ◽  
Naturally Occurring ◽  
Three Phase ◽  
The Difference

Knowledge of carbon isotope fractionation is needed in order to discuss the formation and dissociation of naturally occurring CO2 hydrates. We investigated carbon isotope fractionation during CO2 hydrate formation and measured the three-phase equilibria of 12CO2–H2O and 13CO2–H2O systems. From a crystal structure viewpoint, the difference in the Raman spectra of hydrate-bound 12CO2 and 13CO2 was revealed, although their unit cell size was similar. The δ13C of hydrate-bound CO2 was lower than that of the residual CO2 (1.0–1.5‰) in a formation temperature ranging between 226 K and 278 K. The results show that the small difference between equilibrium pressures of ~0.01 MPa in 12CO2 and 13CO2 hydrates causes carbon isotope fractionation of ~1‰. However, the difference between equilibrium pressures in the 12CO2–H2O and 13CO2–H2O systems was smaller than the standard uncertainties of measurement; more accurate pressure measurement is required for quantitative discussion.

scholarly journals Natural Science and Supernatural Thought Experiments

Religions ◽  
2019 ◽  
Vol 10 (6) ◽  
pp. 389
Author(s):  
James Robert Brown
Keyword(s):  
Natural Science ◽  
Thought Experiment ◽  
Thought Experiments ◽  
The Other ◽  
Space And Time ◽  
Wide Range ◽  
The Difference ◽  
Theological Thought

Religious notions have long played a role in epistemology. Theological thought experiments, in particular, have been effective in a wide range of situations in the sciences. Some of these are merely picturesque, others have been heuristically important, and still others, as I will argue, have played a role that could be called essential. I will illustrate the difference between heuristic and essential with two examples. One of these stems from the Newton–Leibniz debate over the nature of space and time; the other is a thought experiment of my own constructed with the aim of making a case for a more liberal view of evidence in mathematics.

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