bluuebunny/crossref_metadata_2025 huggingface dataset:
Joining Composite Pipes Using Hybrid Heat-Activated Coupling and Adhesive Bonding
Authors: Li Guoqiang , Pang Su-Seng , Jones Randy J. , Helms Jack E. , Woldesenbet Eyassu
Published: April 2020

Deepwater activities are the future of the Offshore Oil and Gas Industry. Huge reserves have been located in the Gulf of Mexico as well as off the Coast of West Africa and Brazil. The development of floating production platforms and vessels offers challenges to the facilities engineer who must consider new materials to meet stringent topsides weight limitations. A critical technology for facilities piping in offshore platforms is joining technique. This paper discusses the development of a hybrid joining approach by using heat-activated coupling and adhesive bonding. The technique procedure is presented via specimen fabrication. A total of eleven coupled specimens are prepared and evaluated using standardized internal pressure tests. The feasibility of this new joining technique in offshore piping is discussed based on the internal pressure test results.
Diamond Enhanced Shear Cutting Elements on Roller Cone Bits
Authors: Scott Dan E. , Skeem Marc R.
Published: April 2020

Polycrystalline diamond (PCD) cutters and drag bit designs have been substantially improved since their 1972 introduction, and PCD drill bits now are approaching the rolling cone tungsten carbide insert (TCI) market is terms of revenue size and have surpassed it in terms of economic impact on the drilling industry.1,2 These performance improvements have lead to a significant encroachment into the drill bit market built upon the breakthrough invention of the rolling cone bit by Howard Hughes Sr. Material and design improvements in the last decade, however, have now led to the successful application of patented shear cutting PCD elements as well as conventional diamond enhanced crushing style inserts on rolling cone bits. Diamond enhanced rolling cone bits are also a growth market for diamond elements in drilling.

Failing rock in shear is a more efficient process than by crushing, but most cutting materials can not stand up to the forces generated in the shearing process as rock strength increases. To take advantage of the unique ability of the PCD cutter to shear rock efficiently, a concerted R&D effort supported by laboratory and field-testing led to the application of diamond as a shear cutting element on roller cone bits. A variety of rolling cone shear cutting elements have been developed and successfully commercialized in the last decade.

This paper will discuss laboratory results and increased field performance achieved relative to conventional crushing style diamond and tungsten carbide inserts. The authors will document through case studies increases in rate of penetration (ROP), footage, overall durability, and gauge holding ability in addition to bearing/seal effectiveness that have further reduced drilling costs and served to increase usage of polycrystalline diamond elements on roller cone bits. These applications range from such diverse markets as high cost offshore North Sea, to low cost North American land operations.
Rate Dependent Gradient Theory for Shear Band Analysis in Clayey Soils
Authors: Voyiadjis George Z. , Song Chung R.
Published: April 2020

A rate dependent, non local approach is developed in this work for geo-materials. A multi-scale gradient theory is addressed for non local approach. Visco-plasticity is also incorporated for an additional regularization of the local behavior. The plastic spin is incorporated to separate the effect of micro-structural rotation from the gradient effect. The flow characteristics of the soil is also incorporated in order to separate the viscosity effect from the flow effect.
Strength Analysis of Adhesive-Bonded Single-Lap Composite Joints
Authors: Huang Hai , Yang C. Charles
Published: April 2020

An analytical model was developed to determine the stress and strain distributions of adhesive-bonded composite single-lap joints under tension. Laminated anisotropic plate theory was applied in the derivation of the governing equations of the two bonded laminates. The adhesive was assumed elastic-perfectly plastic and follows von Mises yield criterion. The entire coupled system was determined through the kinematics and force equilibrium of the adhesive and the adherends. The overall system of governing equations was solved by directly solving the differential equations with appropriate boundary conditions. Computer software Maple was used as the calculation tool in solving these equations. Results from the analytical model were verified with finite element analysis using ABAQUS and also compared with experimental results using specimens defined in ASTM D 3165 “Strength Properties of Adhesives in Shear by Tension Loading of Single-Lap-Joint Laminated Assemblies.” Although all three failure modes of bonded joints, substrate failure, cohesive, and adhesive failure, were present as the test results, only cohesive failure mode was analyzed.
Superior History of Pipeline Remediation
Authors: Crawford Jaime , Crawford James R. , Baugh Benton F.
Published: April 2020

A presentation of field trial information on extended reach pipeline blockage remediation of several jobs in the Gulf of Mexico using technology developed thru the DeepStar CTR 3202 Pipeline Blockage Remediation Project. Projects include Unocal, Vastar, Tana Exploration, Comstock Exploration, Stone Energy, Texaco, and Devon Energy pipelines.
Modeling of Slug Dissipation and Generation in a Hilly-Terrain Pipeline
Authors: Zhang Hong-Quan , Al-Safran Eissa M. , Jayawardena Subash S. , Redus Clifford L. , Brill James P.
Published: April 2020

Hilly-terrain pipelines consist of interconnected horizontal, uphill and downhill sections. Slug flow experiences a transition from one state to another as the pipe inclination angle changes. Normally, slugs dissipate if the upward inclination becomes smaller or the downward inclination becomes larger, and slug generation occurs vice versa. Appropriate prediction of the slug characteristics is crucial for the design of pipeline and downstream facilities. In this study, slug dissipation and generation in a valley pipeline configuration (horizontal-downhill-uphill-horizontal) were modeled by use of the method proposed by Zhang et al. [1]. The method was developed from the unsteady continuity and momentum equations for slug flow by considering the entire film zone as the control volume. Computed results are compared with experimental measurements at different gas-liquid flow rate combinations. Good agreement is observed for the change of slug body length to slug unit length ratio.
JOVA: Java Object Viewing Aid
Authors: Kartaltepe Doğan , Subramaniam Venkat
Published: April 2020

Both the object paradigm and the Java programming language have gained immense popularity over the years. In the recent past the Unified Modeling Language has come to be the standard for the representation of classes and their relationships. Exceptional mechanisms are available to develop html-based documentation from Java source code. However, these documentations are largely text based.

As more developers get involved in developing large-scale systems using Java, it would be of significant benefit to represent classes and relationships between classes using UML. Of course, asking all vendors of Java software libraries to provide UML diagrams for their products/libraries is impractical.

Java Object Viewing Aid uses the feature of reflection to extract the details of classes and relationships from the existing binaries. It then presents this information in a form that is intuitive to software developers. In this paper we present the details and features of JOVA.
Orimulsion® Spill Behavior in Soil
Authors: De Aguiar Jose , Masciangioli Pánfilo , Abreu Enrique
Published: April 2020

This work shows the results of a series of tests conducted at laboratory scale, on spills of Orimulsion® on different types of soils. Several physical procesess such as spreading, infiltration, evaporation, adherence, and capillarity were analyzed. The experimental results are compared with the theoretical results obtained from a formulation based on the viscous fluids spreading equations developed by Huppert [1]. Based on the knowledge gained on the behavior of Orimulsion® spills on soil, it will be possible to select the most suitable techniques to remove the product. In the tests conducted on the behavior of confined Orimulsion® spills on soil, equations for spills both in horizontal and inclined surfaces were validated and calibrated. Such equations provide an excellent adjustment and are a good representation of the phenomenon.
Waste Disposal by Injection Into Deep Wells
Authors: Omrcen Bozidar , Loncaric Bozidar , Brkic Vladislav
Published: April 2020

There has been a long tradition of process waste disposal into existing deep wells in Croatia. Previously, liquids were separated from solids and injected into geologically appropriate formations. Solids were left in the existing mud pits or transferred into selected deposits. An essential disadvantage of such a procedure was the settlement of heavy metals and their penetration into sediments containing fresh water. The authors of this project have elaborated a new technology that presumes joint injection of liquids and solids into deep wells properly designed, so that the slurry may penetrate through geologically adequate formations. Wells have been classified into three groups upon which the following requirements are imposed: (1) reservoir pressure of a selected geological formation is lower than the hydrostatic one; (2) reservoir pressure is higher than the hydrostatic one, but lower than the fracturing pressure of that formation; and (3) possibility of obtaining an injection pressure that creates fractures and thus enables waste disposal. With regard to the fact that a relatively large number of dry exploration wells and depleted production wells exist in Croatia, the study illustrates that a number of wells can be classified into these three groups.

Currently, the technological waste created during drilling, workover, oil and gas production and refining processes is permanently disposed by applying a specific procedure developed in Croatia. Besides, there has been a serious debate over the possibility of a permanent low and middle radioactivity waste disposal created in health services, pharmacy and food industry, following the referred procedure. For that purpose, an adequate law regulation to enable the application of the referred procedure is under preparation.
Stabilisation of Gaslift Production Using a Dynamic Simulator
Authors: Roberts Yvonne V. , Nicol Matt
Published: April 2020

A common problem with gas lifted wells is the development, over time, of instabilities in the injection/production behaviour. The question raised is initially that of “probable cause and effect”; the understanding of which is essential to the determination of possible remedial action.

The major causes of unstable behaviour fall into three broad categories:

• Design related - the original design is inappropriate or inflexible.

• Mechanical - damage to, and/or failure of, valves and equipment.

• Dynamic flow behaviour - changes in fluid composition and/or phase changes.

Commonly, the instability incorporates elements from more than one category.

This paper discusses one case in which a horizontal well in the North Sea, which had a gas lift completion designed for operation at a water cut of around 20%, exhibited unstable production after a rapid rise in water cut to approximately 80%.

The paper shows how a new and unique dynamic gas lift simulator was used to reproduce the observed well behaviour, and how the model was then used to recommend remedial action to stabilise production. The impact of these remedial actions is discussed in the context of the overall production management. Finally, the implementation of the recommendations and the subsequent well behaviour are presented.
Applying High Power Laser Technology in Well Completion
Authors: Batarseh Samih I. , Graves Ramona M. , Batzle Michael
Published: April 2020

Shaped charge jet guns are used in perforation operations to create communication between the formation and the wellbore. The efficiency of this technique is very important for flow performance and production. Over the years, using shaped charge guns has shown that this method caused reduction in production and caused damaged zones in the formation around the perforated tunnel. The damage is a result of the high impact from releasing the bullet into the formation. The bullet produces very fine grain particles that plug or reduce the pore throat size and therefore, causes permeability reduction. This process leaves the perforated tunnel with broken rocks, jet metal and explosive products (mostly carbon).

Laser perforating, a new technology, has the potential to eliminate this damage and actually increase the permeability. Experiments and studies show that lasers improve permeabilities and porosities of the perforated tunnel as well as the adjacent zone. Lasers can be delivered through fiber optics down hole to the target, which eliminates much of the cleaning process and dealing with equipment management.
Application of Systems Analysis to the Flowing and Artificially Lifted Oil Wells in a Selected Oil Field
Authors: Bagci Suat , Odabasi Ali Onursal
Published: April 2020

System analysis is required to produce a development program for an oil and gas field which is a system formed of reservoir, production string, flow restrictions, flow lines and surface facilities. System analysis technique was applied to an oil field in Kazakstan in order to determine the efficient system for the field and to produce a development program. To model the components of the systems commercial softwares were used. The study was commenced with the analysis of data on the reservoir and production as input to the models. The models were tuned through history matching by modifying fluid properties of oil, and basic reservoir description parameters. Following the history match, performances of production strings of different sizes, with and without artificial lifting were compared to determine the most efficient production string for the field.

The analysis verifies that considering the components of an oil and gas production system individually may result in performances lower than optimum. To search for the best development scheme, the production system must considered as a whole. It was determined that all the wells of SSTA, first reservoir unit, should be produced by making use of 2 7/8 in. tubing size, 100 stage D-12 pumps for wells W-77, W-95 and W-110, and 100 stage D-20 pumps for W-79 and W-111. For the other reservoir unit, SST5, use of 2 3/8 in. tubing with 100 stage D-20 pump was advantageous for W-98 and W-Y3, while use of 3 1/2 in. tubing with 200 stage D-12 pump was advantageous for W-116 and W-117.

Finally in the study, development program was formed for the field using the mentioned string-artificial lift combinations. In the end, 517,068 m3 oil was produced from SSTA which corresponds to 42.7% of OOIP with no injection and new production wells. 738,956 m3 of oil was produced from SST5 which corresponds to 27.1% of the OOIP by injecting 1,375,000 m3 water and operating two new production wells.
Possible Detection of Multiple Blockages Using Transients
Authors: Adewumi Michael A. , Eltohami E. S. , Solaja A.
Published: April 2020

This work explores the possibility of utilizing the interaction between a pressure pulse propagating in a pipe with the blockages therein, as a means of blockage detection and characterization. Whereas an earlier work focused on a single blockage, the present work attempts to extend the strategy to multiple blockages. A one-dimensional isothermal non-compositional single-phase Eulerian model was used to describe the propagation of a pressure pulse through a pipe with multiple blockages. Pressure variations at the inlet caused by reflections of the propagating transient are monitored and analyzed. This analysis is used to make deductions about the internal configuration of the pipe. The results demonstrate that the technique is feasible and that accurate characterization of multiple blockages is possible.
An Analytical Approach for Below the Bubble Point, Black-Oil System Production Analysis and Optimization
Authors: Huffman Clark
Published: April 2020

The ability to predict well inflow performance for varying well and reservoir conditions is important when optimizing production. Many methods exist to estimate a well’s current productive capacity (IPR curve) and extensions to the methods are available for predicting future well performance. The extensions to predict future inflow performance behavior account for changes in relative permeability and assume an average reservoir pressure. The applicability and accuracy of the methods depends on knowledge of reservoir parameters which may be difficult to obtain in low permeability reservoirs.

Several authors have presented methods of analyzing and history matching well performance. These methods typically yield reservoir parameters which may be used in the well inflow performance methods in order to investigate the results of varying well production parameters. These methods are particularly useful in low permeability settings where interpretable welltest data may be difficult to obtain or prohibitively expensive.

Currently, the analytical history matching approach is most accurate when applied to single-phase systems. Predictions of black oil reservoir performance below the bubble point can exhibit large error since depletion of the total reservoir energy is not accounted for using the constant gas-oil ratio approach typical for these methods.

This paper presents a method to analyze well performance of black oil systems below the bubble point. The method incorporates a material balance approach to account for changing gas-oil ratios as the reservoir is depleted. Prediction of future well performance is also presented. Along with reservoir characterization, another benefit of the method is the ability to construct IPR curves at any point in order to optimize production. The proposed method uses a pseudo pressure transform to account for changes in fluid properties as the reservoir pressure is depleted. Relative permeability changes can be incorporated in the pseudo pressure transform.

Comparisons to finite difference simulation results and actual productio data are presented. Comparisons of future IPR curves generated by other methods are also presented.
Performance of Venturi Meters in Multiphase Flow
Authors: Hall A. R. W.
Published: April 2020

The results described in this paper are derived from a project whose objective is to compare the results obtained from multiphase flow meters in controlled laboratory conditions with those obtained in real production systems.
Friction Factor Directly From Roughness Measurements
Authors: Sletfjerding Elling , Gudmundsson Jon Steinar
Published: April 2020

Pressure drop experiments on natural gas flow in 150 mm pipes at 80 to 120 bar pressure and high Reynolds number were carried out for pipes smooth to rough surfaces. The roughness was measured with an accurate stylus instrument and analyzed using fractal methods. Using a similar approach to that of Nikuradse the measured friction factor was related to the measured roughness values. Taking the value of the relative roughness and dividing it by the slope of the power spectrum of the measured roughness, a greatly improved fit with the measured friction factor was obtained. Indeed, a new friction factor correlation was obtained, but now formulated in terms of direct measurement of roughness.
Slug Detection As a Tool for Predictive Control of GLCC© Compact Separators
Authors: Earni Shankar , Wang Shoubo , Mohan Ram S. , Shoham Ovadia , Marrelli Jack D.
Published: April 2020

Current design and performance of the GLCC©1 separator is dependent on the prediction of the upstream inlet flow conditions based on available models. It is expected that early detection of terrain slugging (slug length, slug velocity and holdup) and controlling the liquid level in the GLCC using feed forward mechanism can improve the operational range of GLCC, by decreasing the gas carry under and liquid carry over, and thereby decreasing the control valve dynamics. The conventional feedback control loops can seldom achieve perfect control considering the impact of huge slugs that are keeping the output of the process continuously away from desired set point value. The reason is simple: a feedback controller reacts only after it has detected a deviation in the value of the level from the set point. Unlike the feedback systems, a feed forward control configuration measures the disturbance directly and takes control action to negate the effect of the disturbance on liquid level in the GLCC. Therefore, feed forward control system has the theoretical potential for perfect control if the slug detection and characterization are accurate.

A strategy for GLCC predictive control has been proposed which integrates the feedback and feed forward loops to compensate for error due to modeling and slug characterization. A model has been developed for predictive control system design and simulated in MATLAB-Simulink®. Experimental results obtained demonstrate that the proposed strategy is a viable approach for GLCC predictive control.
Evaluation of Mechanical Properties of the Composite Joints With Metal Powder and Electric Current Flow
Authors: Haneji T. , Miyagi K. , Goya M. , Sueyoshi T. , Nakao Z. , Ushio M.
Published: April 2020

The solid-state welding method was applied under atmospheric conditions by using metal powder medium which was interposed in the space between the two solid bars of specimen (i.e., base metal), and was compressed longitudinally and simultaneously current was conducted to generate Joule thermal heat. Some fundamental data on the mechanical and metallurgical properties of the joint were obtained by using resistance welding. In the experiments, the specimen materials used as base metals in this study were pure aluminum, stainless steel and titanium bars of solid, and the powder media were aluminum, nickel and silicon powder. The mixed silicon powder medium increases electric resistance between base metals, moreover, to obtain mechanical properties. Four experiments were conducted with different specimen;

The first experiment used two solid aluminum specimen bars with aluminum powder medium. The second, two solid aluminum specimen bars with mixed aluminum and nickel powder media. The third, two solid aluminum specimen bars with mixed nickel and silicon powder media. And the fourth, solid specimen were different materials and had relatively different melting points. Such as solid aluminum and stainless steel (SUS430) with mixed nickel and silicon powder media, and solid aluminum and titanium with mixed aluminum and nickel powder media.

Data were obtained with the intent of optimizing the method using powder medium between a pair of solid sample specimen and observation, analysis and assessment were made with microscope. Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDX). X-ray Diffraction (XRD), tensile strength, Vickers hardness and bending U-shape flexure tests.
Computations of Higher Class Solutions of Partial Differential Equations
Authors: Surana K. S. , Bona M. A.
Published: April 2020

This paper presents a new computational strategy, computational framework and mathematical framework for numerical computations of higher class solutions of differential and partial differential equations. The approach presented here utilizes ‘strong forms’ of the governing differential equations (GDE’s) and least squares approach in constructing the integral form. The conventional, or currently used, approaches seek the convergence of a solution in a fixed (order) space by h, p or hp-adaptive processes. The fundamental point of departure in the proposed approach is that we seek convergence of the computed solution by changing the orders of the spaces of the basis functions. With this approach convergence rates much higher than those from h,p–processes are achievable and the progressively computed solutions converge to the ‘strong’ i.e. ‘theoretical’ solutions of the GDE’s. Many other benefits of this approach are discussed and demonstrated. Stationary and time-dependant convection-diffusion and Burgers equations are used as model problems.
Dynamics of a Cantilever Beam With Attached Pendulum
Authors: Sado Danuta
Published: April 2020

This work draws attention to the to the analysis of dynamics of a nonlinear coupled cantilever beam-pendulum oscillator. Dynamical systems of this type have important technical applications, because many mechanical components consist of linear or weakly nonlinear continuos substructures such as beam coupled to nonlinear oscillators. The present paper is a continuation of the author’s previous work where in applying the Galerkin method the modal series was truncated at the first mode. In this work it is assumed that the cantilever beam behaves like an Euler-Bernoulli beam and to its end pendulum is attached. The integro-differential equations are transformed into an ordinary differential equations with the use of Galerkin procedure with beam functions. In this study, in applying the Galerkin method the modal series was truncated at the second mode. Next these equations were solved numerically and there was studied the effect of the internal friction on energy transfer in a coupled structure that consist of a linear viscoelastic beam supporting at its tip a nonlinear pendulum.
Gas Liquid Separation Using a GLCC in a Sodium Bicarbonate Solution Mining Operation
Authors: Lansangan Robbie M. , Huffman Mike
Published: April 2020

Nahcolite is a naturally occurring sodium bicarbonate mineral found in subsurface formations. American Soda LLP conducted field tests to prove that nahcolite can be deep mined using low-cost conventional solution mining method. The process involved the injection of hot, high pressure water down wells into a nahcolite deposit about 2,600 feet below the surface where the mineral is dissolved and brought to the surface for recovery.

The monitoring and optimization of recovery efficiency based on scores of upstream process parameters, such as water injection rate, required the monitoring of produced liquid density. This was done initially with a mass meter located immediately downstream of the well head.

Co-production of small amounts of gas, mainly methane and carbon dioxide, entrained in the liquid phase prevented the accurate measurement of the solution density using a Coriolis meter technology. Premier Instruments provided a remedy with a gas liquid cylindrical cyclone (GLCC© 1) separator properly sized and engineered for the process requirements. A gas control valve with liquid level feedback was used to eliminate the entrained gas in the liquid phase. This strategy proved to be functional which allowed American Soda to proceed with the field development. Today, 26 production wells employ the GLCC separator at each production well.
Migration of Clay in Flows of Oil-Water Mixtures Through Sand Filters
Authors: Patel H. R. , Chase G. G.
Published: April 2020

One of the most crucial problems that the petroleum industry has been facing for quite some time, is the damage done to the sandstone formations by the produced water that is pumped into the ground during secondary oil recovery. The drastic reduction in permeability of these sandstone beds due to the water-shock, is a great concern in petroleum industry. The changes in produced water composition has made secondary oil recovery difficult. The decreasing permeability of the bed, increases the pumping and equipment cost to a great extent. The control of clay release is essential to the economic and effective operations in many oil fields.

The main topic of this research is the effect of electrolytic composition in produced water on the clay particles pumped into sandstone formations or through sand-filters. Earlier studies [1–5] have revealed that high pH and low salt concentrations of water lead to release of clay from sand-grains. Also, there might be some clay particles injected into the ground with the produced water. These injected clays get captured by the sandstone bed. Both the release and capture of clays changes the porosity of bed and the surface area of sandstone particles and thus, reduces the permeability of the bed drastically. This paper just presents the experimental work done to predict the release of indigenous clay in the sand filter in aqueous phase flow. Future work will concentrate more on actual filtration experiments to release of indigenous clays and capture of injected clays in aqueous phase flow and the release-capture phenomena in two phase flows as well.

In produced water operations, oil companies need to remove particles from the injection water to avoid formation damage. Consolidated Sand Cartridge filters are an inexpensive alternative compared to tradition means of filtering the particles. This work demonstrates the capability and advantages of these filters. The filter has properties similar to that of sandstone and so, results of clay migration study for the filter may be similar to sandstone bed as well. The Consolidated Sand filter is superior compared to conventional cylindrical sand filters in that its outer surface is expanded out into a six-lobe geometry with a larger surface area for filtration. Hence higher flow rates are achieved through the filter at a given pressure drop and the life of filter increases. Also, it has a glue bound sand structure which reduces the release of clay compared to the conventional sand filters. However, the disadvantage of the filter is that it is bulky and heavy and it adds to the disposal cost for the user. This work serves the dual purpose of characterizing the consolidated sand cartridge filter and also, studying the phenomena of clay release and capture in the sand filter to determine the optimum combination of pH and salt-concentration for minimal permeability loss. The phenomenon of clay release and capture is explained on basis of zeta potential of the particles, which characterize the surface charge of the particles.
The Effect of Drilling Damage on Bearing Strength of Graphite/Epoxy Composites
Authors: Sadat Abdul B.
Published: April 2020

An experimental approach is used to determine the effect of drilling damage on bearing stress of graphite/epoxy composite laminates. An improvement in bearing stress was achieved by placing an aluminum plate contiguous to exit plane and by applying pressure around the hole through a specially made pressure device at the entrance plane. It was also shown that the bearing stress varied with the fiber direction. The bearing stress was maximum in the 45 degree direction.
Gas-phase diagnostic studies of H2 and CH4 inductively coupled plasmas
Authors: Van Surksum Tara L. , Fisher Ellen R.
Published: April 2020

Determination of molecular temperatures within low-temperature plasmas is critical to understanding the reactions that drive the chemistry of these systems and the mechanisms involved in plasma-surface interactions. Optical emission spectroscopy was employed to investigate gas-phase processes in H2 and CH4 inductively coupled plasma systems. Specifically, rotational temperatures (TR) have been determined for H2 d3Πu→a3Σg+ and CH A2Δ→X2Π under a variety of plasma parameter conditions. In 100% H2 plasmas, TR(H2) values are ∼500–550 K, whereas generally higher TR(H2) values (∼500–700 K) are reported for 100% CH4 plasmas. Disparities in the rotational temperature values and trends of H2 (d3Πu) between H2 and CH4 plasmas highlight the differences in H2 excitation pathways occurring in each of these two plasma systems as TR can be affected by the mechanism for molecule formation and excitation within plasma systems. As such, mixed gas CH4/H2 plasma systems were also explored to gain further insight into these mechanistic details. These results emphasize the connections between fundamental plasma properties and plasma parameters, a key component to understanding and optimizing plasma conditions for the future development of a host of plasma technologies.
Frequency modulation of laser ultrasound transducer using carbon nanotube-coated polyethylene microsphere
Authors: Kwon Soo Won , Choi Won Young , Jo Hyeong Geun , Park Kwan Kyu
Published: April 2020

An ultrasound transducer was fabricated by dropping a multi-walled carbon nanotube solution containing a mixture of carbon nanotubes and ethoxyethanol directly on the surface of polyethylene microspheres. The frequency modulation depended on the diameter of the polyethylene microspheres. To investigate this relationship, three types of polyethylene microspheres with different diameters were used in simulations and experiments. These specimens were attached to polydimethylsiloxane and glass plates. A comparison revealed that the 50 μm diameter polyethylene spheres coated with carbon nanotubes had the highest ultrasound frequency. This work showed that smaller polyethylene microspheres generate higher ultrasound frequencies.
Acute Effects of Intermittent Physical Activity on Perceptions of Exercise-Related Fatigue in Children
Authors: Nagy Matthew , O’Sullivan Molly , Block Shannon , Hasson Rebecca E.
Published: April 2020

Purpose: To investigate the acute effects of intermittent activity performed at varying intensities on the perceptions of exercise-related fatigue in children.Methods: A total of 30 children completed 4 experimental conditions in random order, which consisted of 8 hours of sitting interrupted with 20 two-minute low-, moderate-, or high-intensity activity breaks or 20 two-minute sedentary breaks. The perceptions of exercise-related fatigue were determined via the Subjective Exercise Experience Scale at the beginning (0 breaks), middle (after 10 breaks), and end (after 20 breaks) of each condition.Results: The average heart rate was significantly higher with increasing exercise intensity (sedentary: 89.6 ± 1.2 beats/min, low: 114.6 ± 1.8 beats/min, moderate: 147.2 ± 1.8 beats/min, and high: 172.3 ± 1.8 beats/min,P < .0001). There was no significant main effect of condition (sedentary: −0.5 ± 0.6, low: −1.0 ± 0.7, moderate: −0.2 ± 0.5, and high: −0.6 ± 1.2;P = .86) and time (10–0 breaks: −0.7 ± 0.5 and 20–0 breaks: −0.5 ± 0.5;P = .45), nor time by condition interaction (P = .99) on change in exercise-related fatigue.Conclusions: Incorporating intermittent activity into physical activity programs may help to reduce barriers to regular exercise by minimizing perceptions of exercise-related fatigue in children.
Improving patient safety during intrahospital transportation of mechanically ventilated patients with critical illness
Authors: Lin Shwu-Jen , Tsan Chin-Yuan , Su Mao-Yuan , Wu Chao-Ling , Chen Li-Chin , Hsieh Hsiu-Jung , Hsiao Wei-Ling , Cheng Jui-Chen , Kuo Yao-Wen , Jerng Jih-Shuin , Wu Huey-Dong , Sun Jui-Sheng
Published: April 2020

Aim

Intrahospital transportation (IHT) of patients under mechanical ventilation (MV) significantly increases the risk of patient harm. A structured process performed by a well-prepared team with adequate communication among team members plays a vital role in enhancing patient safety during transportation.

Design and implementation

We conducted this quality improvement programme at the intensive care units of a university-affiliated medical centre, focusing on the care of patients under MV who received IHT for CT or MRI examinations. With the interventions based on the analysis finding of the IHT process by healthcare failure mode and effects analysis, we developed and implemented strategies to improve this process, including standardisation of the transportation process, enhancing equipment maintenance and strengthening the teamwork among the transportation teammates. In a subsequent cycle, we developed and implemented a new process with the practice of reminder-assisted briefing. The reminders were printed on cards with mnemonics including ‘VITAL’ (Vital signs, Infusions, Tubes, Alarms and Leave) attached to the transportation monitors for the intensive care unit nurses, ‘STOP’ (Secretions, Tubes, Oxygen and Power) attached to the transportation ventilators for the respiratory therapists and ‘STOP’ (Speak-out, Tubes, Others and Position) attached to the examination equipment for the radiology technicians. We compared the incidence of adverse events and completeness and correctness of the tasks deemed to be essential for effective teamwork before and after implementing the programme.

Results

The implementation of the programme significantly reduced the number and incidence of adverse events (1.08% vs 0.23%, p=0.01). Audits also showed improved teamwork during transportation as the team members showed increased completeness and correctness of the essential IHT tasks (80.8% vs 96.5%, p<0.001).

Conclusion

The implementation of reminder-assisted briefings significantly enhanced patient safety and teamwork behaviours during the IHT of mechanically ventilated patients with critical illness.
Cohort study of neonatal resuscitation skill retention in frontline healthcare facilities in Bihar, India, after PRONTO simulation training
Authors: Higgins Brennan V , Medvedev Melissa M , Spindler Hilary , Ghosh Rakesh , Longkumer Ojungsangla , Cohen Susanna R , Das Aritra , Gore Aboli , Mahapatra Tanmay , Walker Dilys M
Published: April 2020

Background

Use of simulation in neonatal resuscitation (NR) training programmes has increased throughout low-income and middle-income countries. Many of such programmes have demonstrated a positive impact on NR knowledge and skill acquisition along with reduction of early neonatal mortality and fresh stillbirth rates. However, NR skill retention after simulation programmes remains a challenge.

Methods

This study assessed facility level NR skill retention after PRONTO International’s simulation training in Bihar, India. Training was conducted within CARE India’s statewide in-job, on-site Apatkaleen Matritva evam Navjat Tatparta mentoring programme as part of a larger quality improvement and health systems strengthening initiative. Public sector facilities were initially offered training, facilitated by trained nursing graduates, during 8-month phases between September 2015 and January 2017. Repeat training began in February 2018 and was facilitated by peers. NR skills in simulated resuscitations were assessed at the facility level at the midpoint and endpoint of initial training and prior to and at the midpoint of repeat training.

Results

Facilities administering effective positive pressure ventilation and assessing infant heart rate increased (31.1% and 13.1%, respectively, both p=0.03) from midinitial to postinitial training (n=64 primary health centres (PHCs) and 192 simulations). This was followed by a 26.2% and 20.9% decline in these skills respectively over the training gap (p≤0.01). A significant increase (16.1%, p=0.04) in heart rate assessment was observed by the midpoint of repeat training with peer facilitators (n=45 PHCs and 90 simulations). No significant change was observed in other skills assessed.

Conclusions

Despite initial improvement in select NR skills, deterioration was observed at a facility-level post-training. Given the technical nature of NR skills and the departure these skills represent from traditional practices in Bihar, refresher trainings at shorter intervals are likely necessary. Very limited evidence suggests peer simulation facilitators may enable such increased training frequency, but further study is required.
A look at multiparticle production via modified combinants
Authors: Ang Han Wei , Chan Aik Hui , Ghaffar Mahumm , Rybczyński Maciej , Wilk Grzegorz , Włodarczyk Zbigniew
Published: April 2020

As shown recently, one can obtain additional information from the measured charged particle multiplicity distributions,P(N), by investigating the so-called modified combinants,$$C_j$$Cj, extracted from them. This information is encoded in the observed specific oscillatory behaviour of$$C_j$$Cj, which phenomenologically can be described only by some combinations of compound distributions based on the Binomial Distribution. So far this idea has been checked inppand$$e^+e^-$$e+e-processes (where observed oscillations are spectacularly strong). In this paper we continue observation of multiparticle production from the modified combinants perspective by investigating dependencies of the observed oscillatory patterns on type of colliding particles, their energies and the phase space where they are observed. We also offer some tentative explanation based on different types of compound distributions and stochastic branching processes.
Experimental investigation of pressure distribution characteristics of a flying-wing model using PSP
Authors: Wang Hongbiao , Zhu Baoshan , Xiong Jian
Published: April 2020

To investigate the static pressure distribution characteristics of a flying-wing model, an advanced binary pressure sensitive paint (PSP) technique is introduced. It has low-temperature sensitivity and can compensate the errors induced by temperature. The pressure measurement test was performed in 0.6 m trisonic wind tunnel at angles of attack ranging from 0[Formula: see text] to 12[Formula: see text] in supersonic condition, adopting a low-aspect-ratio flying wing model. The binary PSP is sprayed on the upper surface of the model while pressure taps are installed on the upper surface of the right wing. Luminescent images of two probes are acquired with a color charge-coupled-device camera system and processed with calibration results. During the test, the surface pressure is measured by PSP and transducer, respectively. The results obtained show that the binary paint is of advantage to the surface pressure measurement and flow characteristic analysis. The high-resolution pressure spectra at different angle of attack clearly reveal the impact of leading edge vortex on the upper surface pressure distributions. The pressure measured by PSP also agrees well with the pressure tap results. The root mean square error of pressure coefficient is 0.01 at [Formula: see text], [Formula: see text].
A novel approach for finding crucial node using ELECTRE method
Authors: Singh Saurabh , Verma Shashi Kant , Tiwari Akhilesh
Published: April 2020

Terrorist network may be defined as collection of suspected terrorist nodes which may function in disguise towards accomplishing a terrorist activity. They use extensive communication channel for sharing crucial information. Terrorist network analysis is highly efficacious for intelligence analysis and deriving useful conclusions from available data. Computer Science and Network analysis act as pertinent fields for the study and graphical interpretation of these networks. In this paper, we examine the 26/11 Mumbai attack terrorist network dataset and employ the ELECTRE method for identification of key node in the terrorist network. ELECTRE is an effective multi-criteria decision-making model. It provides a framework for structuring a decision problem integrates the quantitative and qualitative factors of the problem and facilitates easy computation. From the 26/11 Mumbai attack dataset of terrorist network, we have determined that out of several terrorists in the network “Wassi” was the momentous and mastermind of all. The proposed work also demonstrates improvement of result in terms of concurrence, generalization accuracy and genuineness. Based on the solution of ELECTRE framework, it is resolved that the obtained (terrorist) nodes will step up the work of law enforcement agencies and enable them to confine their focus on important members of the terrorist network. Identification of key terrorist is highly important for developing long-term strategies to counter forthcoming terrorist attacks. It can be better implemented during the development of smart city especially for India.
Trapezius Transfer to Restore Shoulder Function in Traumatic Brachial Plexus Injury: Revisited and Modified
Authors: Karki Durga , Muthukumar Vamseedharan , Dash Suvashis , Singh Arun K.
Published: April 2020

Background: Trapezius transfer has shown promise to restore shoulder movements and has stood through the passage of time. We here in describe a modification of trapezius transfer technique and review the current literature available.

Methods: The modified trapezius transfer in which the trapezius muscle is extended with folded tensor fascia lata graft and attached as distally possible to the deltoid insertion was done in twelve patients at tertiary health care centre in India. Post-operative splinting and staged physiotherapy were given.

Results: Results were described in the form of improvement in degree of shoulder abduction and Disabilities of the Arm, Shoulder and Hand (DASH) score. Six months post-surgery there were improvement in shoulder abduction and DASH score with mean 116 degrees (10–180 degree) and 38 (23–58) respectively. One patient showed poor results due to poor compliance in post-operative period. There were no major complications observed.

Conclusions: The modified technique of trapezius transfer described here is a feasible option with good biomechanical outcomes. The technique is simple and can be adopted easily by emerging brachial plexus surgeon as a technique for secondary reconstruction of shoulder joint.
Treatment for Wassel Types V and VI Thumb Polydactyly
Authors: Bessho Yuki , Takagi Takehiko , Seki Atsuhito , Takayama Shinichiro
Published: April 2020

Background: Polydactyly of the thumb is the most common congenital anomaly of the hand, but there have been few reports regarding Wassel types V and VI. The purpose of this study is to present our surgical strategies and outcomes for cases of Wassel types V and VI polydactyly of the thumb.

Methods: Twenty-nine thumbs of 29 patients were included in this study; 17 cases were Wassel type V and 12 cases were type VI. Our strategies for initial surgery were appropriate tendon and muscle relocations. Opponensplasty with the abductor digiti minimi or the flexor digitorum superficialis and osteotomy were not performed in the initial surgery. We evaluated pinch motion ability and the number of additional surgical procedures. The first web space and radial instability of the metacarpophalangeal (MCP) joint were measured by radiography while the patient held a polystyrene foam cone.

Results: Twenty-two patients were able to perform a pulp pinch. Narrowing of the first web defined as the angle between the first and second metacarpus (1–2 MCA) < 40° occurred in five cases. Radial instability of the MCP joint defined as the angle between the first metacarpus and thumb proximal phalanx (1 MPA) > 20° occurred in seven cases. Additional surgery was performed in seven cases (24%) to improve insufficient thumb opposition, radial instability of the MCP joint, and narrowing of the first web. Patients in all reoperation cases were able to perform a pulp pinch.

Conclusions: Our strategies for initial surgery often had satisfactory outcomes, but careful follow-up observations and appropriate reoperation for cases with poor initial outcomes were more important.