Maintaining the integrity and longevity of structures is essential in many industries,such as aerospace,nuclear,and petroleum.To achieve the cost-effectiveness of large-scale systems in petroleum drilling,a strong emphasis on structural durability and monitoring is required.This study focuses on the mechanical vibrations that occur in rotary drilling systems,which have a substantial impact on the structural integrity of drilling equipment.The study specifically investigates axial,torsional,and lateral vibrations,which might lead to negative consequences such as bit-bounce,chaotic whirling,and high-frequency stick-slip.These events not only hinder the efficiency of drilling but also lead to exhaustion and harm to the system’s components since they are difficult to be detected and controlled in real time.The study investigates the dynamic interactions of these vibrations,specifically in their high-frequency modes,usingfield data obtained from measurement while drilling.Thefindings have demonstrated the effect of strong coupling between the high-frequency modes of these vibrations on drilling sys-tem performance.The obtained results highlight the importance of considering the interconnected impacts of these vibrations when designing and implementing robust control systems.Therefore,integrating these compo-nents can increase the durability of drill bits and drill strings,as well as improve the ability to monitor and detect damage.Moreover,by exploiting thesefindings,the assessment of structural resilience in rotary drilling systems can be enhanced.Furthermore,the study demonstrates the capacity of structural health monitoring to improve the quality,dependability,and efficiency of rotary drilling systems in the petroleum industry.
Sabrina MeddahSid Ahmed TadjerAbdelhakim IdirKong Fah TeeMohamed Zinelabidine DoghmaneMadjid Kidouche
Multilayered control of myelination:Quick,saltatory conduction of action potentials along nerve fibers requires the electrical insulation of axons by myelinating glia.In the central nervous system,this role is taken up by oligodendrocytes.Oligodendrocytes are marked by the expression of the lineage determinants Sox10 and Olig2 and arise from oligodendrocyte precursor cells(OPCs)during embryonal stages.While the majority of OPCs differentiate into mature oligodendrocytes when nearby axonal segments require myelination,a small subpopulation of OPCs persist as a progenitor pool.Therefore,the timing of myelination and maintenance of the OPC pool both need to be precisely regulated.Different transcription factors either positively or negatively affect oligodendrocyte differentiation and maintenance of the OPC pool as components of a complex gene regulatory network(reviewed in Sock and Wegner,2021).Network activity is additionally influenced by extracellular signaling molecules that bind to receptors on the oligodendroglial cell surface and activate intracellular signaling pathways.How the receptors are linked to the network is poorly understood so far,but pivotal to understanding the overall regulation of central nervous system(CNS)myelination in response to environmental cues.Relevant insights were recently gained for Gpr37(Schmidt et al.,2024),a G-protein coupled receptor(GPCR)with known relevance in differentiating oligodendrocytes(Yang et al,2016).
The electrochemical conversion of carbon dioxide(CO_(2))into chemical fuels represents a promising approach for addressing global carbon balance issues.However,this process is hindered by the kinetic limitations of anodic reactions,usually the oxygen evolution reaction,resulting in less efficient production of high value-added products.Here,we report an integrated electrocatalytic system that couples CO_(2)reduction reaction(CO_(2)RR)with urea oxidation reaction(UOR)using a bifunctional electrocatalyst with atomically dispersed dual-metal CuNi sites anchored on bamboo-like nitrogen-doped carbon nanotubes(CuNi-CNT),which were synthesized through a one-step pyrolysis process.The bifunctional CuNi-CNT catalyst exhibits a near 100%CO Faraday efficiency for CO_(2)RR over a wide potential range and outstanding UOR performance with a negatively shifted potential of 210 mV at 10 mA·cm^(-2).In addition,we assemble a two-electrode electrolyzer using bifunctional CuNi-CNT-modified carbon fiber paper electrodes as both cathode and anode,capable of operating at a remarkably low cell voltage of 1.81 V at 10 mA·cm-2,significantly lower than conventional setups.The study provides a novel avenue to achieving an efficient carbon cycle with reduced electric power consumption.
