The use of the spatial characteristics technique with the view of estimating the explosion wave impact on the stuck drilling string zone / Wykorzystanie techniki charakterystyk przestrzennych do określania wpływu fali uderzeniowej na przychwyconą kolumnę przewodów wiertniczych

2012 ◽  
Vol 57 (3) ◽  
pp. 601-618 ◽  
Author(s):  
Vasyl Moisyshyn ◽  
Vasyl Yacyshyn ◽  
Oleg Vytyaz
Keyword(s):  
Drill Pipe ◽  
Charge Weight ◽  
Practical Implementation ◽  
Problem Solution ◽  
Wave Impact ◽  
Spatial Characteristics ◽  
Explosion Wave ◽  
Deformation State ◽  
Drilling String ◽  
Threaded Joints

Abstract Studied here are the results of the asymmetric problem solution of the thick walled circular cylinder elasticity using the spatial characteristics technique. The practical implementation of the solution of the problem is based on the calculation of the stress-caused deformation state of the stuck drilling string zone affected by the explosion wave action upon the inner wall of the pipe. Suggested here is the technique for determining axual σz and circular σθ stress on the drill pipe wall as well as the radial displacements ur of the stuck drill pipe outer surface under the action of the explosion shock wave. The above technique enables to make a sound selection of the cylindrical explosive charge weight in order to avoid the residual strain during the drilling string shaping off and uncoupling the threaded joints or to prevent them from exceeding the admissible level.

Gravity gradient tensor of a vertical pyramid model of flat top and bottom with depth-wise parabolic density variation

Geophysics ◽  
2019 ◽  
Vol 84 (6) ◽  
pp. G93-G112
Author(s):  
Anand Prakash Gokula ◽  
Rambhatla G. Sastry
Keyword(s):  
Numerical Stability ◽  
Density Variation ◽  
Gravity Gradient ◽  
Practical Implementation ◽  
Problem Solution ◽  
Contrast Variation ◽  
Gradient Tensor ◽  
Gravity Gradient Tensor ◽  
Pyramid Model

As an alternative to the popular rectangular parallelepiped model, we have developed a novel 3D analytical forward-problem solution for the gravity gradient tensor of a vertical pyramid model with parabolic density contrast variation. Its flexibility and effectiveness are demonstrated with the help of synthetic simulations and a case study involving Chintalapudi subbasin, India. We have addressed the singularities and numerical stability in numerical implementation of our algorithm for modeling and practical implementation.

Fracture Failure Analysis of 127mmG105 Drill Pipe

2012 ◽  
Vol 184-185 ◽  
pp. 248-251
Author(s):  
Fang Po Li ◽  
Shu Mao Zhang ◽  
Yong Gang Liu ◽  
Xin Xu
Keyword(s):  
Mechanical Properties ◽  
Failure Analysis ◽  
Drill Pipe ◽  
Fracture Analysis ◽  
Drilling Process ◽  
Fracture Failure ◽  
Drilling String ◽  
Mechanical Properties Testing

The failure cause of one Φ127mm G105 drill pipe was investigated through mechanical properties testing, optical morphologies and fracture analysis. The results show that drill pipe’s failure reason is the "martensite" white bright layer in its out-surface caused by intense friction in drilling process. Under the effect of torque and tensile loads, lots of cracks initiated in the white bright layer and developed along the vertical. In the end, when its tensile capacity was less than the weight of drilling string, drill pipe fractured along the horizontal. In addition, H2S in the travelling environment promoted crack’s initiation and development.

An Overview of Digital Image Processing and Recognition (Invited Paper)

1982 ◽  
Vol 40 ◽  
pp. 700-702
Author(s):  
R. C. Gonzalez
Keyword(s):  
Image Processing ◽  
New York ◽  
Digital Image Processing ◽  
Digital Image ◽  
Practical Implementation ◽  
Submarine Cable ◽  
Vigorous Growth ◽  
Digitized Pictures ◽  
Processing Techniques ◽  
And Storage

Interest in digital image processing techniques dates back to the early 1920's, when digitized pictures of world news events were first transmitted by submarine cable between New York and London. Applications of digital image processing concepts, however, did not become widespread until the middle 1960's, when third-generation digital computers began to offer the speed and storage capabilities required for practical implementation of image processing algorithms. Since then, this area has experienced vigorous growth, having been a subject of interdisciplinary research in fields ranging from engineering and computer science to biology, chemistry, and medicine.

P20 phosphor on polyimide as a large area high-resolution transmission screen for slow scan CCD systems

1995 ◽  
Vol 53 ◽  
pp. 20-21
Author(s):  
C. C. Ahn ◽  
S. Karnes ◽  
M. Lvovsky ◽  
C. M. Garland ◽  
H. A. Atwater ◽  
...  
Keyword(s):  
Mechanical Stability ◽  
High Energy ◽  
Practical Implementation ◽  
Line Pair ◽  
Modulation Transfer ◽  
Large Area ◽  
Ccd Imaging ◽  
Transmission Electron ◽  
The One ◽  
Beam Broadening

The bane of CCD imaging systems for transmission electron microscopy at intermediate and high voltages has been their relatively poor modulation transfer function (MTF), or line pair resolution. The problem originates primarily with the phosphor screen. On the one hand, screens should be thick so that as many incident electrons as possible are converted to photons, yielding a high detective quantum efficiency(DQE). The MTF diminishes as a function of scintillator thickness however, and to some extent as a function of fluorescence within the scintillator substrates. Fan has noted that the use of a thin layer of phosphor beneath a self supporting 2μ, thick Al substrate might provide the most appropriate compromise for high DQE and MTF in transmission electron microcscopes which operate at higher voltages. Monte Carlo simulations of high energy electron trajectories reveal that only little beam broadening occurs within this thickness of Al film. Consequently, the MTF is limited predominantly by broadening within the thin phosphor underlayer. There are difficulties however, in the practical implementation of this design, associated mostly with the mechanical stability of the Al support film.

In Search of Somatic Precursors of Spontaneous Insight

2018 ◽  
Vol 32 (3) ◽  
pp. 97-105 ◽  
Author(s):  
Wangbing Shen ◽  
Yuan Yuan ◽  
Chaoying Tang ◽  
Chunhua Shi ◽  
Chang Liu ◽  
...  
Keyword(s):  
Problem Solving ◽  
Direct Evidence ◽  
Electrodermal Activity ◽  
Cardiovascular Responses ◽  
Solution Time ◽  
Problem Solution ◽  
Insight Problem ◽  
Creative Insight ◽  
Insight Problem Solving ◽  
Analytic Problem

Abstract. A considerable number of behavioral and neuroscientific studies on insight problem solving have revealed behavioral and neural correlates of the dynamic insight process; however, somatic correlates, particularly somatic precursors of creative insight, remain undetermined. To characterize the somatic precursor of spontaneous insight, 22 healthy volunteers were recruited to solve the compound remote associate (CRA) task in which a problem can be solved by either an insight or an analytic strategy. The participants’ peripheral nervous activities, particularly electrodermal and cardiovascular responses, were continuously monitored and separately measured. The results revealed a greater skin conductance magnitude for insight trials than for non-insight trials in the 4-s time span prior to problem solutions and two marginally significant correlations between pre-solution heart rate variability (HRV) and the solution time of insight trials. Our findings provide the first direct evidence that spontaneous insight in problem solving is a somatically peculiar process that is distinct from the stepwise process of analytic problem solving and can be represented by a special somatic precursor, which is a stronger pre-solution electrodermal activity and a correlation between problem solution time and certain HRV indicators such as the root mean square successive difference (RMSSD).

Direct ammonia fueled solid oxide fuel cells: A comprehensive review on challenges, opportunities and future outlooks

2020 ◽  
pp. 70-91 ◽  
Author(s):  
Molla Asmare ◽  
Mustafa Ilbas
Keyword(s):  
Electric Power ◽  
Energy Demand ◽  
Renewable Energy Sources ◽  
Clean Energy ◽  
Performance Comparison ◽  
Optimum Operating ◽  
Practical Implementation ◽  
Human Society ◽  
Energy Access ◽  
Green Fuel

Nowadays, the most decisive challenges we are fronting are perfectly clean energy making for equitable and sustainable modern energy access, and battling the emerging alteration of the climate. This is because, carbon-rich fuels are the fundamental supply of utilized energy for strengthening human society, and it will be sustained in the near future. In connection with this, electrochemical technologies are an emerging and domineering tool for efficiently transforming the existing scarce fossil fuels and renewable energy sources into electric power with a trivial environmental impact. Compared with conventional power generation technologies, SOFC that operate at high temperature is emerging as a frontrunner to convert the fuels chemical energy into electric power and permits the deployment of varieties of fuels with negligible ecological destructions. According to this critical review, direct ammonia is obtained as a primary possible choice and price-effective green fuel for T-SOFCs. This is because T-SOFCs have higher volumetric power density, mechanically stable, and high thermal shocking resistance. Also, there is no sealing issue problem which is the chronic issues of the planar one. As a result, the toxicity of ammonia to use as a fuel is minimized if there may be a leakage during operation. It is portable and manageable that can be work everywhere when there is energy demand. Besides, manufacturing, onboard hydrogen deposition, and transportation infrastructure connected snags of hydrogen will be solved using ammonia. Ammonia is a low-priced carbon-neutral source of energy and has more stored volumetric energy compared with hydrogen. Yet, to utilize direct NH3 as a means of hydrogen carrier and an alternative green fuel in T-SOFCs practically determining the optimum operating temperatures, reactant flow rates, electrode porosities, pressure, the position of the anode, thickness and diameters of the tube are still requiring further improvement. Therefore, mathematical modeling ought to be developed to determine these parameters before planning for experimental work. Also, a performance comparison of AS, ES, and CS- T-SOFC powered with direct NH3 will be investigated and best-performed support will be carefully chosen for practical implementation and an experimental study will be conducted for verification based on optimum parameter values obtained from numerical modeling.

Hydrostatic Fiber Optic Liquid Level Sensor with position sensitive detector

Metrologiya ◽  
2020 ◽  
pp. 38-51
Author(s):  
V. N. Astapov ◽  
I. N. Kozlova
Keyword(s):  
Fiber Optic ◽  
Effective Area ◽  
Raw Material ◽  
Position Sensitive Detector ◽  
Fiber Optic Sensor ◽  
Liquid Level ◽  
Problem Solution ◽  
Sensitive Detector ◽  
Position Sensitive ◽  
Triangulation Sensor

This article presents the rationale and methodology for developing an intrinsically safe device, namely, a hydrostatic fiber optic sensor with a position-sensitive detector for monitoring the level of oil products in large-capacity tanks at oil depots and during pumping in a raw material warehouses. This device suitable for continuous monitoring of the liquid level, based on the measurement of a hydrostatic column of liquid with automatic offset of changes in the density of the liquid. Offset is carried out by means of a displacer (a fully submerged float), inside which a housing with a position-sensitive detector (PSD) is integrated. Theoretical validation of the bellows suspension usage for a displacer is given. During filling a container with a liquid whose level is measured, liquid bellows, the movement of which is recorded by an optical triangulation sensor using the reflected infrared ray incident on the bottom of the bellows. The principle of the triangulation sensor operation is based on the geometric properties of the triangles. The pulses of infrared radiation come through a fiber optic cable. In order to measure the movement of the surface (the bottom of the bellows) by measuring the movement of the reflected beam, a position-sensitive detector is used, which is located in a remote controller. In this device for the intrinsic safety problem solution, optical inputs of a fiber optic flat cable are located in the active zone of the sensor, which is connected to the optical inputs of a position-sensitive detector, operated on the principles of photoelectric effect. The light spot moving along the sensitive zone and converted by the detector into a one-dimensional signal proportional to the distance to the object. hydrostatically applies pressure over the entire effective area of the measuring

Measurements method of the audio recordings acoustic quality indicator prepared for registration and processing in the Unified Biometric System

2019 ◽  
pp. 40-46 ◽  
Author(s):  
V.V. Savchenko ◽  
A.V. Savchenko
Keyword(s):  
Quality Control ◽  
Small Sample Size ◽  
Personal Data ◽  
Digital Processing ◽  
Small Sample ◽  
Practical Implementation ◽  
Acoustic Measurements ◽  
Pitch Frequency ◽  
Wide Range ◽  
Automated Quality Control

We consider the task of automated quality control of sound recordings containing voice samples of individuals. It is shown that in this task the most acute is the small sample size. In order to overcome this problem, we propose the novel method of acoustic measurements based on relative stability of the pitch frequency within a voice sample of short duration. An example of its practical implementation using aninter-periodic accumulation of a speech signal is considered. An experimental study with specially developed software provides statistical estimates of the effectiveness of the proposed method in noisy environments. It is shown that this method rejects the audio recording as unsuitable for a voice biometric identification with a probability of 0,95 or more for a signal to noise ratio below 15 dB. The obtained results are intended for use in the development of new and modifying existing systems of collecting and automated quality control of biometric personal data. The article is intended for a wide range of specialists in the field of acoustic measurements and digital processing of speech signals, as well as for practitioners who organize the work of authorized organizations in preparing for registration samples of biometric personal data.

Method for measuring distortions of a speech signal during its transmission over a communication channel to a biometric identification system

2020 ◽  
pp. 65-72
Author(s):  
V. V. Savchenko ◽  
A. V. Savchenko
Keyword(s):  
Speech Signal ◽  
Communication Channel ◽  
Speaker Identification ◽  
A Priori ◽  
Small Samples ◽  
Practical Implementation ◽  
Identification System ◽  
New Information ◽  
Discrimination Criterion ◽  
A Priori Uncertainty

This paper is devoted to the presence of distortions in a speech signal transmitted over a communication channel to a biometric system during voice-based remote identification. We propose to preliminary correct the frequency spectrum of the received signal based on the pre-distortion principle. Taking into account a priori uncertainty, a new information indicator of speech signal distortions and a method for measuring it in conditions of small samples of observations are proposed. An example of fast practical implementation of the method based on a parametric spectral analysis algorithm is considered. Experimental results of our approach are provided for three different versions of communication channel. It is shown that the usage of the proposed method makes it possible to transform the initially distorted speech signal into compliance on the registered voice template by using acceptable information discrimination criterion. It is demonstrated that our approach may be used in existing biometric systems and technologies of speaker identification.

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