A Novel Method of Assessment of Spurt and Filtrate Related Formation Damage Potential of Drilling and Drilling-in Fluids

2003 ◽  
Author(s):  
Md. Amanullah
Keyword(s):  
Formation Damage ◽  
Damage Potential ◽  
Novel Method ◽  
Method Of Assessment

scholarly journals A Novel Method of Assessment for Monitoring Neuromuscular Fatigue in Australian Rules Football Players

2019 ◽  
Vol 14 (5) ◽  
pp. 598-605 ◽  
Author(s):  
Joel Garrett ◽  
Stuart R. Graham ◽  
Roger G. Eston ◽  
Darren J. Burgess ◽  
Lachlan J. Garrett ◽  
...  
Keyword(s):  
High Performance ◽  
Recovery Phase ◽  
Neuromuscular Fatigue ◽  
Football Players ◽  
Alternative Method ◽  
Jump Test ◽  
Australian Rules Football ◽  
Novel Method ◽  
Run Test ◽  
Method Of Assessment

Purpose: To compare the sensitivity of a submaximal run test (SRT) with a countermovement-jump test (CMJ) to provide an alternative method of measuring neuromuscular fatigue (NMF) in high-performance sport. Methods: A total of 23 professional and semiprofessional Australian rules football players performed an SRT and CMJ test prematch and 48 and 96 h postmatch. Variables from accelerometers recorded during the SRT were player load 1D up (vertical vector), player load 1D side (mediolateral vector), and player load 1D forward (anteroposterior vector). Meaningful difference was examined through magnitude-based inferences (effect size [ES]), with reliability assessed as typical error of measurements expressed as coefficient of variance. Results: A small decrease in CMJ height, ES −0.43 ± 0.39 (likely), was observed 48 h postmatch before returning to baseline 96 h postmatch. This was accompanied by corresponding moderate decreases in the SRT variables player load 1D up, ES −0.60 ± 0.51 (likely), and player load 1D side, ES −0.74 ± 0.57 (likely), 48 h postmatch before also returning to prematch baseline. Conclusion: The results suggest that in the presence of NMF, players use an alternative running profile to produce the same external output (ie, time). This indicates that changes in accelerometer variables during an SRT can be used as an alternative method of measuring NMF in high-performance Australian rules football and provides a flexible option for monitoring changes in the recovery phase postmatch.

scholarly journals The Effect of String Tension Variation on the Perceived Pitch of a Classical Guitar

2014 ◽  
Vol 2 (1) ◽  
pp. 53-81
Author(s):  
Wanda Jadwiga Lewis ◽  
James Raphael Smith ◽  
Wanda J. Lewis ◽  
James R. Smith
Keyword(s):  
Classical Theory ◽  
Fundamental Mode ◽  
String Tension ◽  
Classical Guitar ◽  
Sound Waves ◽  
Single Wave ◽  
Geometric Stiffness ◽  
Vibrating String ◽  
Novel Method ◽  
Method Of Assessment

Actual motion of a vibrating guitar string is a superposition of many possible shapes (modes) in which it could vibrate. Each of these modes has a corresponding frequency, and the lowest frequency is associated with a shape idealised as a single wave, referred to as the fundamental mode. The other contributing modes, each with their own progressively higher frequency, are referred to as overtones, or harmonics. By attaching a string to a medium (a soundboard) capable of a response to the vibrating string, sound waves are generated. The sound heard is dominated by the fundamental mode, ‘coloured’ by contributions from the overtones, as explained by the classical theory of vibration. The classical theory, however, assumes that the string tension remains constant during vibration, and this cannot be strictly true; when considering just the fundamental mode, string tension will reach two maximum changes, as it oscillates up and down. These changes, occurring twice during the fundamental period match the frequency of the octave higher, 1st overtone. It is therefore plausible to think that the changing tension effect, through increased force on the bridge and, therefore, greater soundboard deflection, could be amplifying the colouring effect of (at least) the 1st overtone.In this paper, we examine the possible influence of string tension variation on tonal response of a classical guitar. We use a perturbation model based on the classical result for a string in general vibration in conjunction with a novel method of assessment of plucking force that incorporates the engineering concept of geometric stiffness, to assess the magnitude of the normal force exerted by the string on the bridge. The results of our model show that the effect of tension variation is significantly smaller than that due to the installed initial static tension, and affects predominantly the force contribution arising from the fundamental mode. We, therefore, conclude that string tension variation does not contribute significantly to tonal response. Photo credit: By Biblola (Own work) [CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0)], via Wikimedia Commons

Novel Method of Assessing Practical Intelligence Acquired in Mechatronics Laboratory Classes

2015 ◽  
pp. 895-928
Author(s):  
Zol Bahri Razali
Keyword(s):  
Engineering Education ◽  
Engineering Students ◽  
Explicit Knowledge ◽  
Assessment Instruments ◽  
Practical Intelligence ◽  
Work Related ◽  
Novel Method ◽  
The Difference ◽  
Representative Work ◽  
Method Of Assessment

Practical intelligence is often referred to as the ability of a person to solve practical challenges in a given domain. The lack of practical intelligence may be due to the way in which explicit knowledge is valued and subsequently assessed in engineering education, namely via examinations, tests, laboratory reports, and tutorial exercises. The lack of effective assessments on practical intelligence indicates implicit devaluation, which can significantly impair engineering students' ability to acquire practical intelligence. To solve this problem, the authors propose a new method of assessment for measuring practical intelligence acquired by engineering students after performing engineering laboratory classes. The novices-experts approach is used in designing the assessment instruments, based on the behaviors' of novices/experts observed and novices/experts representative work-related situations. The practical intelligence can be measured by calculating the difference between participants' and the experts' ratings; the closer the novices to experts, the higher the practical intelligence acquired.

Scale Dissolver Application: Production Enhancement and Formation-Damage Potential

2000 ◽  
Vol 15 (04) ◽  
pp. 288-295 ◽  
Author(s):  
M.M. Jordan ◽  
G.M. Graham ◽  
K.S. Sorbie ◽  
A. Matharu ◽  
R. Tomlins ◽  
...  
Keyword(s):  
Formation Damage ◽  
Damage Potential

Investigations on the Damage Potential of Drilling Fluids: HT/HP-Return-Permeability Tests Under Dynamic Conditions

2017 ◽  
Author(s):  
Carsten Freese
Keyword(s):  
Best Practice ◽  
Mercury Porosimetry ◽  
German Society ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Damage Potential ◽  
Material Particle ◽  
Dynamic Conditions ◽  
Gaseous Hydrocarbons ◽  
Set Up

In view of the increasing scarcity of energy resources, wells are being drilled to progressively greater depths for the production of liquid and gaseous hydrocarbons. Economical exploitation of these HT/HP reservoirs is possible only with the application of drilling and completion methods which do not damage the formation. Here, the reservoir-saving exposure of these deposits is an essential contribution. The damage potential of drilling fluids and treatment fluids is usually assessed on the basis of return permeability (RP) tests. An impairment of the effective rock permeability through appropriate candidate fluids (drill in fluids, etc.) can be measured with special laboratory tests. In addition to the RP-Tests further investigations should be made to estimate the formation damage such as high-resolution digital photography, mercury porosimetry, scanning electron microscopy as well as microsection analyses. Within the framework of the German Society for Petroleum and Coal Science and Technology a project was carried out to evaluate common formation damage test facilities and to define the “best practice” meeting the requirements of RP-measurements under borehole-like conditions. After a thorough evaluation an advanced HT/HP facility for formation damage testing was designed and built. By using of this set-up, systematic return-permeability tests were performed under dynamic conditions for temperatures up to 180 °C, for a flow pressure up to 250 bar, and a mantle pressure up to 350 bar. This paper presents results from a study on the filtration and formation damage behaviour of drilling fluids under variation of the concentration and of the weighting material particle size distribution. Furthermore, promising results from changing dynamic and static filtration experiments are discussed.

scholarly journals Novel method for high-throughput phenotyping of sleep in mice

2007 ◽  
Vol 28 (2) ◽  
pp. 232-238 ◽  
Author(s):  
Allan I. Pack ◽  
Raymond J. Galante ◽  
Greg Maislin ◽  
Jacqueline Cater ◽  
Dimitris Metaxas ◽  
...  
Keyword(s):  
High Throughput ◽  
High Throughput Screening ◽  
Time Of Day ◽  
Chemical Mutagenesis ◽  
High Throughput Phenotyping ◽  
Novel Method ◽  
Initial Implantation ◽  
Method Of Assessment ◽  
Digital Video Analysis ◽  
Electroencephalogram Eeg

Assessment of sleep in mice currently requires initial implantation of chronic electrodes for assessment of electroencephalogram (EEG) and electromyogram (EMG) followed by time to recover from surgery. Hence, it is not ideal for high-throughput screening. To address this deficiency, a method of assessment of sleep and wakefulness in mice has been developed based on assessment of activity/inactivity either by digital video analysis or by breaking infrared beams in the mouse cage. It is based on the algorithm that any episode of continuous inactivity of ≥40 s is predicted to be sleep. The method gives excellent agreement in C57BL/6J male mice with simultaneous assessment of sleep by EEG/EMG recording. The average agreement over 8,640 10-s epochs in 24 h is 92% ( n = 7 mice) with agreement in individual mice being 88–94%. Average EEG/EMG determined sleep per 2-h interval across the day was 59.4 min. The estimated mean difference (bias) per 2-h interval between inactivity-defined sleep and EEG/EMG-defined sleep was only 1.0 min (95% confidence interval for mean bias −0.06 to +2.6 min). The standard deviation of differences (precision) was 7.5 min per 2-h interval with 95% limits of agreement ranging from −13.7 to +15.7 min. Although bias significantly varied by time of day ( P = 0.0007), the magnitude of time-of-day differences was not large (average bias during lights on and lights off was +5.0 and −3.0 min per 2-h interval, respectively). This method has applications in chemical mutagenesis and for studies of molecular changes in brain with sleep/wakefulness.

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