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Optimizing sampling frequency of surface and downhole measurements for efficient stick-slip vibration detection

Petroleum 2024年第1期10卷 30-38页

作者： Saket Srivastava aditya sharma Catalin Teodoriu Mewbourne School of Petroleum and Geological Engineering The University of Oklahoma

Drilling vibrations significantly impact drilling operations with high costs due to early downhole equipment failure and loss of productive time. Stick-slip vibrations, a severe form of torsional vibrations,is known to be present up to 50% of total drilling time, making it a topic of immense concern and research. An ongoing discussion in the industry is regarding the reliability of surface measurements for early detection of severe downhole bit sticking. Moreover, most surface measurements are sampled at lower frequency rates closer to 1 Hz. Recently, the implementation of advanced data acquisition modules in downhole subs has greatly improved our understanding of drilling vibrations through high resolution data, sampled up to 10 kHz. However, with a wide range of sampling frequency to choose from different available tools, a critical question remains unanswered. What is an optimal and adequate sampling frequency for early detection of downhole vibrations using both surface and downhole measurements?The paper addresses the question with a focus on stick-slip vibrations through an experimental investigation. Stick slip tests are repeated for different sampling frequencies of surface and downhole measurements and the stick slip index for each case is calculated. The stick-slip index varies for different sampling frequency even though the vibration tests remain completely identical. It was inferred that sampling frequency of measurements greatly impact the detection of downhole vibrations. Even though stick-slip vibrations are characteristically low frequency vibrations(≤2Hz), a minimum of 10Hz sampling frequency is recommended for detection of stick-slip vibrations. Moreover, all characteristics of stick-slip vibrations including bit sticking, bit RPM peaks and negative bit RPMs are clearly observed at a minimum of 100Hz sampling rate.

关键词： Stick-slip

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A review of torsional vibration mitigation techniques using active control and machine learning strategies

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PETROLEUM 2024年第3期10卷 411-426页

作者： sharma, aditya Abid, Khizar Srivastava, Saket Velasquez, Andres Felipe Baena Teodoriu, Catalin Univ Oklahoma Norman OK 73019 USA

Drilling is one of the most challenging and expensive processes in hydrocarbon extraction and geothermal well development. Dysfunctions faced during drilling can increase the non-productive time (NPT) greatly, resulting in inflating the drilling cost and also pose a safety concern. One of the main problems faced during drilling that limits the life of drilling equipment and tools and decreases the overall productivity of the system is drilling vibrations. These vibrations can be categorized into three modes: axial, lateral, and torsional. Stick-slip vibrations are a type of torsional vibration in which the bottom hole assembly (BHA) periodically stops to rotate followed by a spike in the bottom hole RPM. This paper provides a comprehensive review of techniques used to control and mitigate torsional vibration with an emphasis on stick-slip. A brief introduction to drillstring and friction modeling is presented followed by a concise summary of passive control techniques to control stick-slip. Then the focus is shifted to an up-to-date review of active control and machine learning for stick-slip control and mitigation. The paper ultimately highlights the importance of adapting novel control and mitigation concepts to improve stick slip detection and improve the overall drilling process. A unique solution is insufficient to control a complex process such as drilling, but integration of various techniques has been found promising. (c) 2023 Southwest Petroleum University. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd. This is an open access article under the CC BY-NC-ND license (http:// ***/licenses/by-nc-nd/4.0/).

关键词： Drilling vibrations Controllers Mitigations strategies Stick slip Torsional vibrations Machine Learning STICK-SLIP OSCILLATIONS DRILLSTRING VIBRATION BENDING VIBRATIONS OUTPUT-FEEDBACK DRAG BITS DESIGN SUPPRESSION STABILITY SYSTEM MODEL

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Fear of missing out: A brief overview of origin, theoretical underpinnings and relationship with mental health

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World Journal of Clinical Cases 2021年第19期9卷 4881-4889页

作者： Mayank Gupta aditya sharma Clarion Psychiatric Center and Department of Child and Adolescent Psychiatry Lake Erie College of Osteopathic MedicineClarionPA 16214United States Department of Neuroscience University of PittsburghPittsburghPA 15213United States

Fear of missing out(FoMO)is a unique term introduced in 2004 to describe a phenomenon observed on social networking *** includes two processes;firstly,perception of missing out,followed up with a compulsive behavior to maintain these social *** are interested in understanding the complex construct of FoMO and its relations to the need to belong and form stable interpersonal *** is associated with a range of negative life experiences and feelings,due to it being considered a problematic attachment to social *** have provided a general review of the literature and have summarized the findings in relation to mental health,social functioning,sleep,academic performance and productivity,neuro-developmental disorders,and physical *** have also discussed the treatment options available for FoMo based on cognitive behavior *** imperative that new findings on FoMO are communicated to the clinical community as it has diagnostic implications and could be a confounding variable in those who do not respond to treatment as usual.

关键词： Fear of missing out Mental health Physical well-being Academic performance Fear of missing out-reduction Problematic social media

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Study of Wetting Properties of Carbon Nanofiber Coatings on Various Substrates

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Journal of Physical Science and Application 2014年第8期4卷 493-500页

作者： Sonal Mazumder aditya sharma Akanksha Department of Chemical Engineering BITS Pilani Pilani Rajasthan 333031 India

The role of roughness and composition on the wetting characteristics of a series of carbon nanofiber based coatings were studied in order to evaluate its superhydrophobic properties. In this study, idealized surfaces were created from a smooth stainless steel and aluminium sheets and two other stainless steel sheets with different textured surfaces. All surfaces were coated with carbon nanofiber alcohol solutions in order to generate coatings of variable compositions using mixtures of isopropanol, water and a commercial carbon nanofibre. The optimum concentration of carbon nanofiber in coatings was obtained to produce superhydrophobic surfaces. A general trend of increasing hydrophobicity was observed for coated surfaces as compared to the bare substrate. Individual contact angles were dependent on the nature of the underlying substrate, relative surface pattern, and roughness. Overall wetting properties were dependent upon composition and micro scale roughness of the coatings.

关键词： Contact angle wetting coatings carbon nanofiber superhydrophobicity.

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Management of bladder pheochromocytoma by transurethral resection

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Asian Journal of Urology 2019年第3期6卷 298-301页

作者： aditya P.sharma Girdhar S.Bora Ravimohan S.Mavuduru Vikas K.Panwar Bhagwant R.Mittal Shrawan K.Singh Department of Urology Postgraduate Institute of Medical Education and ResearchChandigarhIndia Department of Nuclear Medicine Postgraduate Institute of Medical Education and ResearchChandigarhIndia

Bladder pheochromocytoma is the most common extra-adrenal genitourinary *** management is feared due to the risk of intra-operative hypertensive *** described a case of successful endoscopic management of a bladder ph... 详细信息

关键词： Transurethral resection Bladder Pheochromocytoma Paraganglioma

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Numerical simulation of square shaped particle sedimentation

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Particuology 2024年第1期84卷 107-116页

作者： Govind sharma Bahni Ray Department of Mechanical Engineering Indian Institute of Technology DelhiHauz KhasNew Delhi110016India

Direct numerical simulations of square particle sedimentation in a viscous incompressible fluid are presented to examine the effects of sharp edges for various particle-to-fluid density ratios and different initial inclination *** settling process exhibits four different motion regimes;non-oscillatory,non-uniform centered oscillatory,uniform off-centered oscillatory,and non-uniform off-centered(irregular)*** moderate density ratios,we observe that the rotational motion of settling square particle varies with the initial inclination *** employ Dynamic Time Warping and Fast Fourier Transform to analyze translational and angular *** systems are described using phase-space plots,and a chaotic phenomenon is observed at a higher density ratio.

关键词： Sedimentation Distributed Lagrangian multiplier Phase synchronization Oscillations

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Sequential decay analysis of^(235)U(n^(th),f)reaction using fragmentation approach

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Chinese Physics C 2024年第6期48卷 145-154页

作者： Nitin sharma Ashutosh Kaushik Manoj K.sharma School of Physics and Materials Science Thapar Institute of Engineering&TechnologyPatiala-147004PunjabIndia

Numerous experimental and theoretical observations have concluded that the probability of the three fragment emission(ternary fission)or binary fission increases when one proceeds towards the heavy mass region of nuclear periodic *** factors affect fragment emission,such as the shell effect,deformation,orientation,and fissility *** and ternary fissions are observed for both ground and excited states of the *** collinear cluster tripartition(CCT)channel of the^(235)U(n^(th),f)reaction is studied,and we observe that the CCT may be a sequential or simultaneous emission *** date,different approaches have been introduced to study the CCT process as a simultaneous or sequential process,but the decay dynamics of these modes have not been not fully *** the three fragments of the sequential process and exploring their related dynamics using an excitation energy dependent approach would be of further ***,in this study,we investigate the sequential decay mechanism of the^(235)U(n^(th),f)reaction using quantum mechanical fragmentation theory(QMFT).The decay mechanism is considered in two steps,where initially,the nucleus splits into an asymmetric *** the second step,the heavy fragment obtained in the first step divides into two *** I analysis is conducted by calculating the fragmentation potential and preformation probability for the spherical and deformed choices of the decaying *** most probable fragment combination of stage I are identified with respect to the dips in the fragmentation structure and the corresponding maxima of the preformation probability(P0).The light fragments of the identified decay channels(obtained in step I)agree closely with the experimentally observed *** excitation energy of the decay channel is calculated using an iteration *** excitation energy is shared using an excitation energy dependent level density *** obtained excitation

关键词： fission cluster radioactivity ternary fission spontaneous fission cluster model total kinetic energy preformation probability

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Comprehending drivers of land use land cover change from 1999 to 2021 in the Pithoragarh District,Kumaon Himalaya,Uttarakhand,India

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Journal of Mountain Science 2024年第7期21卷 2394-2407页

作者： Mahika PHARTIYAL Sanjeev sharma Centre for the Study of Regional Development Jawaharlal Nehru UniversityNew Delhi 110067India

The Himalayan region has been experiencing stark impacts of climate change,demographic and livelihood pattern *** analysis of land use and land cover(LULC)change provides insights into the shifts in spatial and temporal patterns of *** changes are the combined effects of anthropogenic and natural/climatic *** present study attempts to monitor and comprehend the main drivers behind LULC changes(1999-2021)in the Himalayan region of Pithoragarh district,*** district is a border district,remotely located in the north-east region of Uttarakhand,*** study draws upon primary and secondary data sources.A total of 400 household surveys and five group discussions from 38 villages were conducted randomly to understand the climate perception of the local community and the drivers of *** imagery,CRU(Climatic Research Unit)climate data and climate perception data from the field have been used to comprehensively comprehend,analyze,and discuss the trends and reasons for LULC *** and remote sensing techniques were used to construct LULC *** multifaceted approach ensures comprehensive and corroborated *** classes were identified and formed viz-cultivation,barren,settlement,snow,and *** show that vegetation and builtup have increased whereas cultivation,barren land,and snow cover have *** study further aims to elucidate the causes behind LULC changes in the spatially heterogeneous region,distinguishing between those attributed to human activities,climate shifts,and the interconnected impacts of *** study provides a comprehensive picture of the study area and delivers a targeted understanding of local drivers and their potential remedies by offering a foundation for formulating sustainable adaptation policies in the region.

关键词： Himalayan region Land use/land cover change Anthropogenic factors Climate change Socioecological system

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Study of plasma parameters of coaxial plasma source using triple Langmuir probe and Faraday cup diagnostics

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Plasma Science and Technology 2024年第4期26卷 94-100页

作者： Sunil KANCHI Rohit SHUKLA Archana sharma Pulsed Power and Electromagnetics Division Bhabha Atomic Research CentreVisakhapatnam 531011India Homi Bhabha National Institute Mumbai 400085India Beam Technology Development Group Bhabha Atomic Research CentreMumbai 400085India

Coaxial plasma guns are a type of plasma source that produces plasma which propagates radially and axially controlled by the shape of the ground electrode, which has attracted much interest in several applications. In this work, a 120° opening angle of CPG nozzle is used as a plasma gun configuration that operates at the energy of 150 J. The ionization of polyethylene insulator between the electrodes of the gun produces a cloud of hydrogen and carbon *** triple Langmuir probe and Faraday cup are used to measure plasma density and plasma temperature. These methods are used to measure the on-axis and off-axis plasma divergence of the coaxial plasma gun. The peak values of ion densities measured at a distance of 25 mm on-axis from the plasma gun are(1.6±0.5)×10^(19)m^(-3)and(2.8±0.6)×10^(19)m^(-3)for hydrogen and carbon plasma respectively and the peak temperature is 3.02±0.5 eV. The mean propagation velocity of plasma is calculated using the transit times of plasma at different distances from the plasma gun and is found to be 4.54±0.25 cm/μs and 1.81±0.18 cm/μs for hydrogen and carbon plasma respectively. The Debye radius is obtained from the measured experimental data that satisfies the thin sheath approximation. The shot-to-shot stability of plasma parameters facilitates the use of plasma guns in laboratory experiments. These types of plasma sources can be used in many applications like plasma opening switches, plasma devices, and as plasma sources.

关键词： coaxial plasma source triple Langmuir probe Faraday cup plasma density plasma temperature

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Mitigating fire risks in hospitals:Are we primed and geared up?

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Asian Pacific Journal of Tropical Medicine 2024年第3期17卷 141-142页

作者： Raman sharma Sruti sharma Department of Hospital Administration PGIMERChandigarhIndia Department of Hospital Administration Satellite CentreSangrurPGIMERChandigarhIndia

The recent incidents have confirmed that fires in COVID-19 hospitals have become a gruelling and nerve-testing challenge[1-3].The increased volumes of oxygen flow,abundance of inflammable alcohol sanitizers,wearing of inflammable kits,and abundance of equipment make it more acquiescent for such incidents and even difficult to *** density of equipment(especially ventilators)“enriches”air with oxygen,thereby increasing the“combustion risk”.

关键词： nit thereby control

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