Steel String Research Articles

New capabilities of application of gamma-ray logging in borehole geophysical investigations through steel string

Borehole geophysical investigations through steel string (both drill and casing) are becoming increasingly important. Gamma-ray logging (GR) is a mandatory and one of the main methods for investigating oil-and-gas reservoirs and near-surface rocks. It is characterized by high efficiency under the aforementioned measurement conditions. GR is used to identify bed boundaries, evaluate lithology, estimate shaliness, identify reservoirs, etc. Traditionally, the determination of granu- lometric shaliness is the main goal of quantitative interpretation for GR. Gamma-ray logging has been successfully used for many decades. However, increasing the accuracy of determining granulometric shaliness, expanding the informativeness of the method to determine mineral clayness, and developing procedures for using GR data in estimating other petrophysical parameters are topical issues. Based on logging materials, the paper examines the features of using the main interpretation parameter of GR (the relative difference parameter – index ΔІγ) in boreholes in the presence of a steel column and proposes new methodological approaches to the use of GR data when interpreting measurements in oil-and-gas and engineering-geological boreholes. Through numerous ex- amples, the invariance (constancy) of the interpretation parameter of gamma-ray logging has been proven under different borehole conditions, types of logging tools, etc. An approach has been proposed for obtaining optimal reference values when determining this parameter, which increases the accuracy of estimating shaliness parameters. A method has been developed for determining mineral clayness, which is an important quantity in itself and is necessary for determining other petrophysical parameters from loggingdata. A multiplicative method has been created for determining the total porosity of shaly rocks using a combination of neutron logging and gamma-ray logging, which makes it possible to avoid using the hydrogen index of clay minerals. The novelty of the developments is supported by patents, and their effectiveness is confirmed by the results of borehole tests and comparisons with independent determinations of parameters (laboratory core studies, traditional methods of interpretation). The proposed approaches are an important component of the investigation technologies for oil-and-gas reservoirs and near-surface rocks, developed at the Institute of Geophysics of the National Academy of Sciences of Ukraine.

Nonmetallic-Based Tubulars Provide Superior Integrity, Cost Savings

_ This article, written by JPT Technology Editor Chris Carpenter, contains highlights of paper SPE 214647, “Operational Experience From the Implementation of 21 Wells With Nonmetallic-Based Downhole Tubing: From Pilot to Large-Scale Implementation,” by Mohamad H. Ahmad, ADNOC. The paper has not been peer reviewed. _ Tubular glass-reinforced-epoxy (GRE) lining technology has been applied globally since the 1960s in eliminating downhole tubular corrosion. Compared with conventional carbon steel, which can experience frequent failure, GRE-lined carbon steel provides long-lasting protection, resulting in huge savings in life-cycle cost. The operator implemented this technology for a successful trial of water-disposal wells. In the complete paper, the authors share the data from caliper logs run into, and the inspection of tubing pulled from, these disposal wells after 4 years in service. Tubular Corrosion in Operator Assets A growing emphasis on water disposal was inevitable because so much water was being produced with increased water cut and production. ADNOC Onshore operates almost 200 water-disposal wells. However, corrosion has been a common problem in these wells, such that a failure has been reported every 1–2 years. Use of corrosion-prone carbon steel for disposal strings has led to integrity issues and the need for expensive workover jobs that could cost between $1.5 million and $2 million per job. Fiberglass GRE Lining Since 2014, the operator has run 19 water-disposal wells with GRE-lined carbon steel strings. No failures have been reported, and inspections have been successful. Fiberglass tubular lining protects the internal surface of the tubing or casing inside the steel joint. Cement is pumped into the annulus between the GRE-liner outer diameter (OD) and the steel‑pipe inner diameter (ID). The final product is a completely corrosion-protected string, even under the connection area, where accessories called flares and corrosion barrier rings (CBRs) are installed (Fig. 1). The mechanical capability of the system is maintained by the steel pipe, while the internal fiberglass liner provides reliable corrosion resistance. Fiberglass Liner. The fiberglass liner shows excellent resistance in corrosive environments. As per tested and as per the manufacturer’s data sheets, the fiberglass lining system can be used in temperatures of up to 145°C, depending on hydrogen sulfide and CO2 levels in the flowing fluid. Besides being corrosion‑resistant, fiberglass lining improves the flow rate of the flowing water or oil because of the superior surface-energy properties and manufacturing quality of the liner material. The thickness of the liner varies according to the tubing size (diameter). Cement. The cement transfer applies pressure directly to the steel pipe. The cement does not bond the fiberglass liner to the steel and allows relative micromovement between the fiberglass liner and the steel pipe resulting from the difference in the thermal expansion coefficient of these two materials. Being alkaline, the cement tends to neutralize the possible presence of acid gases migrating in the fiberglass‑steel annulus; this further reduces the possibility of carbon-steel-pipe corrosion.

Evaluation of the acoustic performance of a novelty cathodic protection system against guitar steel strings corrosion

This work was conducted to establish the efficiency of an impressed current cathodic protection system for musical instruments’ steel strings in protecting them from corrosion caused by human sweat. To conduct this research, the harmonic content degradation of a guitar string subjected to different corrosion stages by artificial human sweat, with and without cathodic protection by an impressed current, was studied. String corrosion is characterised by not only the electrochemical technique of polarisation resistance, but also by weight loss by gravimetric measurements and FESEM microscopy. From the correlation between the acoustic and electrochemical results, it can be concluded that harmonic content degradation of guitar strings increases corrosion but is less significant in the strings protected by impressed current.

Kajian Organologi Pembuatan Gitar Akustik Solid Steel String Model Dreadnought Produksi GuitarUs Klaten

Purpose: This study aims to describe the process of making a solid steel string Dreadnought acoustic guitar produced by GuitarUs and describe the characteristics of this acoustic guitar based on three aspects of sound, playability and craftsmanship, which later this data can be used as a reference in choosing a good quality steel string acoustic guitar. Method: this research uses qualitative research with a grounded theory approach, namely valid, objective and reliable research results presented by researchers based on a combination of observational data extracted from several GuitarUs luthier partners with observational data obtained from GuitarUs. Results and Discussion: The results of the research obtained are that a good, quality Dreadnought solid steel string acoustic guitar must meet the requirements for the three aspects of sound, playability and craftsmanship, which requirements can be fulfilled if in carrying out the production process, a luthier must apply the knowledge of organology and steel string acoustic guitar acoustics.

Wood for guitars II : How the material properties of a spruce guitar top influence the tonal quality of the guitar

Pacific Rim Tonewoods is the world’s largest supplier of spruce tonewood for the soundboard and bracing of the acoustic guitar. A previous study from our research group (JASA 2019) has demonstrated the importance of (1) longitudinal Young’s Modulus and (2) density of the spruce soundboard on the tonal quality of steel string guitars. This study used pairwise comparisons of listener preference to rank a particular guitar model (the Taylor 814ce). The present study updates this previous work, adding a third material property: internal friction (damping) of the soundboard, as measured by the logarithmic decrement of the resonating spruce billet. In addition, objective data on tonal quality were measured on guitars recorded in an anechoic chamber at the Technical University of Dresden, Germany. Spectral sequence analysis, transfer function, and tone decay were measured, and are correlated with the perceptual data. With these data, we can demonstrate the relative importance of the three material properties on the “performance factors” of guitar quality, such as volume, responsiveness, timbre, attack, and sustain. In doing so, we hope to provide the lutherie community with a predictable means of integrating tonewood material properties into their designs, in order to consistently produce their desired tonal outcomes.

The Acoustic Characteristics of Vocal Twang

The Acoustic Characteristics of Vocal Twang Ingo R. Titze (bio) VOICE RESEARCH AND TECHNOLOGY Vocalists are capable of imitating many of the sound qualities of musical instruments. As with impersonation of sounds other humans make, a caricature of the main feature of the instrumental sound is produced. Vocal timbre can be flute-like, brass-like, or percussive. Often the desired sound quality is that of the instruments that accompany the voice. Give the vastly different geometry and material properties of the human airway compared to those of musical instruments, only one or two acoustic features can usually be imitated. The word “twang” comes from the sound of a plucked guitar string. There is little in common between guitar strings transmitting sound to wooden plates and vocal folds transmitting sound through a 17 cm vocal tract, yet a common feature can be the clustering of frequencies produced. Woodhouse published frequency spectra of plucked guitar strings. Regardless of the pitch produced, the dominant harmonics clustered around 1500–2000 Hz. The fundamental frequency was never the dominant one.1 Such a frequency spectrum can be approximated by shaping the vocal tract such that both the epilaryngeal and the pharyngeal airway are narrow. The bottom row of Figure 1 shows this airway configuration in comparison to other shapes that produce different voice qualities, such as neutral, yawn, ring, and call. On the right panel, the input impedance to the vocal tract is shown for each configuration in the 100–2000 Hz region. The thin line is input resistance and the thick line is input reactance. High positive reactance means that harmonics are reinforced by the vocal tract. Note that twang has the highest reactance between 800 Hz and 1600 Hz. (The ring configuration has its highest reactance in the 3000–4000 Hz range, not shown in Figure 1). With a variety of tongue and lip configurations, the impedance peaks in the 1000–2000 Hz range can be moved up and down, as well as closer together or farther apart. Saldias et al. have shown midsagittal airway images that clearly show the narrowing in the epilaryngeal and pharyngeal regions in twang phonation. They have also shown that the corresponding spectrum has a broad peak in the 1000–2000 Hz region.2 A second feature of twang is nonsteadiness. The spectrum of a plucked string does not remain constant. It is transient as the sound dies out. A sharp twang drifts to a more mellow twang. A singer can imitate this transient quality by keeping the vowel or vocal fold adduction variable. Country singers often [End Page 613] make their vowels more speech-like, drifting from one vowel to another with co-articulation. This is in contrast to classical singers, who often maintain a steady voice quality, thereby mimicking steady tone instruments, such as flutes, brasses, and bowed strings. Click for larger view View full resolution Figure 1. (left) Airway shapes and (right) corresponding vocal tract input impedance over a 100–2000 Hz frequency range. Thin lines are resistances and thick lines are reactances. This author has had multiple conversations with singing teachers about what constitutes “twang” in the industry. In an audition, singers may be asked to produce a twang sound, but it comes out more like a belt or a pressed voice. My advice would be to listen carefully to the sound of a plucked steel string. Imitate that sound first in isolation, then embed that quality into running speech, and finally “sang a sawng” with it. Ingo R. Titze NOTES 1. J. Woodhouse, “Plucked Guitar Transients: Comparison of Measurements and Synthesis,” Acta Acustica united with Acustica 90, no. 5 (September/October 2004): 945–965. 2. Marcelo Saldías, Anne-Maria Laukkanen, Marco Guzmán, Gonzalo, Maranda, Justin, Stoney, Paavo Alku, and Johan Sundberg, “The Vocal Tract in Loud Twang-Like Singing While Producing High and Low Pitches,” Journal of Voice 35, no. 5 (September 2021): 807.e1–807.e23. Copyright © 2022 National Association of Teachers of Singing, Inc

Abstract

Abstract Justin Balog (bio) Gardeners zip tie the branchesof their saplings Magnetic northis the consciousness of birds Stiff weight despite the pain of low barometric pressureI’m on my knees praying for a part-time job If I could I wouldn’t say anything to Greenland its disappearing icerates which have never before been seen My hands sift through dirt that might never have been sifted throughI bought a plant for this responsibility Here we are moving as ifsome destiny tied us By morning the leaves will have already turnedto face the sun [End Page 207] Observation on Discovery I learn the Spaniards take their time, if not for health, maybe for the cascade of Pedrell down the narrow eaves of this near-dawn Catalonian boulevard where I am lost. I stop to stare at the map I stole from a boutique hotel, though the receptionist was so kind, on the street that opens like a harbor of boating flags, a canopy of clothes hanging from the balconies. If this is art, I think I finally understand. In the museum I visited earlier, the main installation was a floating bed frame, connected by steel strings, to the ceiling, above the main entrance, which, to me, seemed an apt description of faith. The bed, though, illustrated some current theory of the universe, the movement of gravity or the bending of light. How precious, then, are our moments of weightlessness? [End Page 208] My only friend in this country, drunk, without our keys, is two or four streets over, hopefully, where I left him. When he told me he had lost our keys, my heart felt as weightless as a toolbox. Where would we stay? We have a train in seven hours. What about our clothes? Or the hosts we’ve betrayed? Forgive me, I took the map because I am in a hurry. The unusual thing about the installation was that the sheets were rigid fishnets or a dark chicken wire. Light makes density ambiguous and gravity throws sheets like a chore. I am taking a minute to myself, in an alley, under a balcony, to breathe because I am sober and have to find us a place to sleep. I lean my head back against the gothic brick. The narrowness between buildings makes the perfect telescope. The shirts, the sheets, the delicateness of their gravity; night peeking through, exhibiting what I think the installation meant: a sculpture rotating with the Earth, everywhere, dangling like little experiments. How precious, these clothes we live in. [End Page 209] Justin Balog Justin Balog is a writer from Beach Park, Illinois. He holds a BS in biology from the University of Wisconsin–Madison. A graduate of the University of Michigan’s Helen Zell Writers’ Program with his MFA in poetry, he has received fellowships from the Vermont Studio Center and the University of Michigan. He was an assistant editor at Michigan Quarterly Review, where he co-founded MQR’s online, multimodal imprint, Mixtape. He has work appearing in Ploughshares, Narrative, and the Iowa Review. Currently, he is a student at Harvard’s Graduate School of Education. Copyright © 2022 Middlebury College

Positively Monstrous!

Positively Monstrous!

Information System for Railway Inspection using Drone and Image Processing

Train is the main mode of transportation that we often use, the train itself can be used as a tool for shipping goods and mobilizing passengers, this transportation is very unique and has its own path in the form of steel strings across from hundreds of kilometers, railroad bearing structures currently exist which uses concrete and wood, the railroad is very vital and is an important supporting facility. The process of railroad monitoring is complex and complicated, takes a long time, the previous method is simple and conventional by tracing the railroad tracks manually or using a geometric gauge mounted direl or also known as railpod, railpod will follow the rails and will provide report if there is a train track that is damaged, broken or shifted, this research will create an image-based monitoring system using drones as a track monitor, another way is to take pictures using satellite data that will provide clear information about road conditions before being passed by the train, the railroad data processing system by using image processing can display visual responses up to cm in size, the response appears if there is a shift in the path then the system directly provides data in the form of location and shifting paths on the main computer, this system is more c eTat in checking and analyzing train track data with high accuracy and precision up to 90%, in addition to imagery from satellite images can use drones, drones themselves are very easy in maintenance and use and are able to cut production costs and even workplace accidents in the field workers themselves can be avoided because the drone is able to reach the track and railroad that is difficult for example through the tunnel or the railroad track along the hills and densely populated.

Pressure Drop if Tetraflouroethane in Small Hydraulic Diameter Capillary Tubes

Developing a compact device has become a current trend in this modern world which pertains to a lesser energy consumption. It also applies to a mini refrigerator unit to accommodate a small device being cooled wherein the cooling unit has to be in a smaller configuration compared with the conventional sizes. This study focuses on the pressure drop of capillary tubes with six(6) different small hydraulic diameters of 0.20mm, 0.25mm, 0.30mm, 0.35mm, 0.40mm, and 0.45mm with 3 different total lengths of 300mm, 600mm, and 900 mm. Tetraflouroethane liquid refrigerant is used as the cooling medium for the refrigeration system which allows the expansion of the refrigerant in order to absorb heat from the surroundings. In fabricating these six(6) different small hydraulic diameters, stainless steel strings were inserted into the conventional capillary tubes to reduce and attain the required hydraulic diameters. The pressure sensors were installed and pressure readings were then obtained in every 300-mm section of the capillary tube assembly. By allowing the pressurized tetrafluoroethane refrigerant to flow from its reservoir tank through the capillary tubes, pressure readings were taken by the data logger in every 300-mm section of the capillary tube. With these data, the pressure drops were then calculated. Pressure drop of all the six(6) sets of capillary tubes were tested and analyzed. The result showed that the 0.20mm with a length of 900 mm capillary tube has the greatest pressure drop compared to the other specimens of the capillary tubes. It then implies that fabricating a small hydraulic diameter of capillary tube as small as 0.20mm by stainless steel string insertion is possible for 300-mm section, however for the longer section it needs more skills in inserting the string.

The natural variability of spruce soundboards: Perceptual differences in the in the tonal quality of acoustic guitars

The wood of the spruce tree (Picea spp.) has been valued for centuries as an ideal soundboard for stringed instruments, due to its material acoustic properties. There is large variability in these properties between individual trees of the same species, and even within an individual log. It stands to reason that this variability would produce audible differences in sound quality in otherwise identical musical instruments. Further, there may be a specific combination of material properties of the soundboard that would result in optimal sound quality for a given design, as measured by expert listeners. Nine steel string guitars of the same model were produced by the Taylor Guitar Company, with strict control of all production parameters. The guitars varied only in two parameters: the density and the Young's modulus of the soundboard and bracewood. A short music sequence was used for pairwise comparisons in a double-blind listening test. The results suggest that, for this particular model (the Taylor 814ce Grand Auditorium), low density and Young's modulus of the soundboard and bracewood have a positive impact on overall preference. More generally, these results underscore the importance of integrating a given design with the physical characteristics of the component wood.

Zubin Kanga: Silver Screens / Steel Strings, London, City, University of London, 26 March 2019

Zubin Kanga has about as wide a range of performance experience as one can get playing recently written art music – his bio mentions collaborations with contemporary warhorses like Thomas Adès, George Benjamin, and Steve Reich – but as a solo performer he has cultivated a distinctive and specialised practice that maps onto the wider action of international New Music in increasingly fascinating ways. For the past few years, his solo tours have showcased an expanded practice which binds the performer to one or another technological apparatus that centrally determines the form and execution of the piece, raising questions of autonomy, authorship and identity. These concerns are reflected in the titles of the tours: ‘Dark Twin’, ‘Cyborg Pianist’ and, currently, ‘Piano Ex Machina’.

Force reflection in a pneumatic artificial muscle actuated haptic system

This paper presents a systematic technique guideline for a haptic-enabled device driven by a pneumatic artificial muscle (PAM) actuator. The proposed haptic system that can serve as a simulator or rehabilitation device was built with a steel string fixed at one end and the other end connected to a control stick. While operating the control stick, a force reflection to the human user can be experienced by human tactile sensation or kinesthetic sensation. To improve the realism presence of the haptic force, three haptic control architectures have been considered for the force feedback features. The corresponding adaptive fuzzy sliding mode controllers were then designed to compensate for the structure and parametric uncertainties to enhance the fidelity feeling of the reflection force. Maneuver tests were conducted for the proposed haptic architectures and controllers. Comparisons were made through the force tracking results.

Cathodic protection of steel guitar strings against the corrosive effect of human sweat

Abstract The steel strings of guitars suffer aggressive corrosion when exposed to human sweat. To mitigate this effect, in this research work guitar strings were subjected to cathodic protection by impressed current. To evaluate the corrosion, electrochemical techniques were used to determine the polarization resistance and the instantaneous corrosion rate, as well as the weight loss by gravimetric measurements. Microphotographs were also carried out to compare the corrosion status of the steel strings by stereoscopic optical and field emission scanning electron microscopy. Impressed current cathodic protection allowed the formation of iron oxides on steel guitar strings to be reduced by around 40%.

Pneumatic Artificial Muscle-Driven Control Loading System (iFUZZY2017)

A control loading system (CLS) provides a force feel about the state of devices. In this paper, the technique for a pneumatic artificial muscle (PAM)-actuated control loading system is developed. The proposed PAM-based control loading system is made with a steel string fixed at one end and the other end connected to a control column, and a force feedback to an operator can be achieved according to the system state. In order to demonstrate the dynamic force feedback characteristics, a second-order mass-spring-damper model is used for the computed force, and the force control is implemented via the position-loop architecture. Moreover, due to the structure and parametric uncertainties of the designed control loading system, the adaptive fuzzy sliding mode controller are employed to improve the fidelity feeling of the force exerted on the control column. Benchmark tests compare the adaptive fuzzy sliding mode controller with other controllers. Results demonstrate the designed PAM-driven control loading system.

Theoretical and experimental investigations of acoustic waves in embedded fluid-solid multi-string structures

Current acoustic measurements provide viable inspection for single cased wells, yet their interpretation for complicated multi-string wellbores where, for instance, two or more nested steel strings are deployed, is largely hampered by a lack of knowledge of the measured acoustic wave fields. This letter reports on theoretical and experimental investigations of the acoustic wave propagation in fluid-filled double string systems. Experimental measurements show excellent agreement with the theoretical predictions by a Sweeping Frequency Finite Element Method. The results lead to the identification of acoustic signatures that are crucial for an effective diagnosis of cement conditions in double-string cased wellbores.

Evolution of the piano

The first pianos were built around 1700 and unlike the case with many other instruments, we know precisely what the first pianos were like since several of them still exist. These early pianos were patterned after Italian harpsichords of the time, with the plucking mechanism of the harpsichord replaced by an “action” mechanism that enabled hammers to strike the strings. The first pianos had a compass of four octaves with brass and iron strings, and a frame composed of wood. The design of those instruments along with the various stages of their evolution into the modern piano with its 88 notes, steel strings and a cast iron plate will be described. The manner in which this evolution was driven by the needs of composers and musicians along with advances in technology will also be discussed.

An experimental modal analysis on the coimbra model of the Portuguese guitar

The most distinctive Portuguese traditional music style is Fado. In this form of Portuguese music, a singer is accompanied by two instruments: a classical guitar and a pear shaped plucked chordophone with six courses of double strings—the Portuguese guitar. There are two distinct types of this instrument—the Lisbon and the Coimbra models—named after the towns where the two different styles of Fado have developed. These guitars differ basically on their size and tuning, both comprising 6 orders of double steel strings, while the construction method (strutting patterns, wood species used, and soundboard thickness distribution) vary for different builders. As part of an ongoing research project that investigates the vibroacoustical behavior of this instrument for different types of designs, an experimental modal analysis of a fully assembled Coimbra guitar was performed. In this work, we present the results of this analysis showing the main characteristics of the frequency response curves and significant vibratory modes as compared to other similar plucked-string instruments.

Determination of energy dissipation of a spider silk structure under impulsive loading

Various researches and studies have demonstrated that spider silk is much stronger and more deformable than a steel string of the same diameter from a mechanical approach. These excellent properties have caused many scientific disciplines to get involved, such as bio-mechanics, bio-materials and bio-mimetics, in order to create a material of similar properties and characteristics. It should be noted that the researches and studies have been oriented mainly as a quasi-static model. For this research, the analysis has taken a dynamic approach and determined the dissipation energy of a structure which is made of spider silk “Dragline” and produced by the Argiope-Argentata spider, through an analytical-experimental way, when being subjected to impulsive loading. Both experimental and analytical results, the latter obtained by using adjusted models, have given high levels of dissipation energy during the first cycle of vibration, which are consistent with the values suggested by other authors.

Correlations between acoustic and electrochemical measurements for metallic corrosion on steel strings used in guitars

The corrosion state of steel guitar strings and their morphology were evaluated according to exposure time to artificial human sweat solution. The instantaneous corrosion rate was evaluated using polarization resistance. Electrochemical impedance spectroscopy was used to measure the strings' state due to corrosion in artificial human sweat solution. Modification of vibroacoustic parameters was analyzed: changes in harmonic content of sound were studied by means of the Fast Fourier Transform and spectrograms. The correlation between corrosion and acoustic measurements was established in the successive stages of corrosion. Thus, the strings' acoustic properties could be modified by means of controlled corrosion processes.