bluuebunny/crossref_metadata_2025_split huggingface dataset:
Research on Active Power Loss Distribution of Components in Magnetic Coupling Wired Drill Pipe
Authors: Jia Jia , Shen Yue , Zhang Xiuwen 
Published: December 2024

Abstract
The magnetic coupling wired drill pipe achieves high-speed information transmission by installing cable at the rod and embedding magnetic couplers at the joints. However, significant energy attenuation in these connected wired drill pipes necessitates the addition of relay circuit compensation every few hundred meters, increasing system complexity and cost. The equivalent circuit of magnetic coupling wired drill pipe can be regarded as a series connection of a coaxial cable line, high-frequency transformer, and terminal load. Exploring better wired drill pipe parameters to distribute signal power across different frequencies will optimize power at the terminal load and improve relay distance. This research establishes a mathematical model for active power distribution in magnetic coupling wired drill pipes based on circuit analysis. The model’s accuracy is validated through circuit simulation and numerical analysis. Reducing signal energy attenuation in the cable and coupler is achieved by increasing the coil coupling coefficient, reducing the coil resistance, and altering the characteristic impedance of the coaxial cable. This research provides a theoretical tool for analysing active power loss distribution of components in wired drill pipe.
Application of perforation pressure gauge in offshore ARP+TCP combined well testing
Authors: Yang Yi , Bai Linkun , Zhao Hongtao 
Published: December 2024

Abstract
The Annulus Pressure Responsive (Hereinafter called ARP) + Tubing Conveyed Perforating (Hereinafter called TCP) combined test technology is widely used in the offshore exploration well. However, the perforation will produce a huge impact load instantaneously and pose a certain threat to the safety of the test column. Researchers usually use numerical simulation method to analyze the dynamic response and stress intensity of the column to achieve the purpose of optimizing it, but the numerical method usually requires a large number of parameters and is inconvenient to apply in the field operation. In this paper, combined with the real data measured by the perforation pressure gauge, a simple and useful prediction formula for the peak perforation pressure was established. The relative error between predicted and measured value was 2.83% and 13.92% respectively for verification by two example Wells. The rapid prediction of peak pressure provides theoretical guidance for optimizing and adjusting test string and perforation parameters and improving operation safety.
Force analysis and optimization design of flexible connection shafts with centerline passing
Authors: Wang Zhiguo , Shi Hongjiang , Sun Qi , Chen Mingzhang , Lu Yiping , Yang Wenjing 
Published: December 2024

Abstract
In response to the design and research of downhole signals transmitted through cables for drilling instruments, the wire passing structure of the cross screw motor is particularly crucial. A preliminary analysis and summary of the material characteristics and stress analysis of its bending tube were conducted. The analysis shows that, under the premise of verifying the strength composite design requirements of its mechanical structure and material performance, the bending tube is subjected to multiple effects of working conditions such as internal stress and alternating load, Gradually forming dangerous cross-sections and stress concentration areas, thereby increasing the risk of fatigue fracture failure. In addition, structural design and material adjustments were made to the stress concentration area, optimizing and improving the contact head structure of the flexible tube. This was verified through material performance analysis, further improving the service life of the flexible tube.
Continuous measurement assists dynamic adjustment of wellbore trajectory
Authors: Sun Quanhua , Yue Bujiang , Li Na , Ma Huibin , Song Dianguang , Shi Lin , Mao Xing 
Published: December 2024

Abstract
In the process of directional well drilling, how to accurately model the real-time well trajectory is of great significance to improving the reservoir encounter rate and recovery rate. This paper provides a method to improve the accuracy of well trajectory by cleaning and correcting the continuous measurement data in combination with fixed measurement data, and then using the continuous measurement data for trajectory modeling. The continuous measurement data comes from the CG-STEER rotary steerable system. The well trajectory calculated by the continuous measurement data corrected by the above method greatly reduces the vertical depth calculation error during the drilling process, and effectively reduces the vertical depth error accumulation caused by the large spacing between fixed measurement points. It can effectively improve the drilling target accuracy and horizontal section penetration rate, and reduce invalid drilling.
Real-time error analysis and anti-collision evaluation of cluster well trajectory
Authors: Zhang Zhifa , Liu Wei , Qian Haodong , Wang Zhendong , Peng Taojun , Zhang Fan , Tian Peiyu 
Published: December 2024

Abstract
The shale gas in Sichuan Basin adopts the horizontal well development mode of well factory, which can reduce the investment cost of exploration and development. However, due to the small well spacing of cluster platform wells, the risk of collision between current wells and adjacent wells is high, so it is necessary to conduct real-time trajectory error analysis and anti-collision evaluation. Usually, the anti-collision monitoring of cluster well trajectory is mostly carried out by field personnel after drilling for a certain distance, and the efficiency of anti-collision analysis is slow. With the popularization of digital drilling site, the timeliness of borehole trajectory data acquisition is guaranteed. Therefore, a set of anti-collision evaluation method of computer real-time trajectory error analyzer is proposed by means of computer analysis, so as to improve the efficiency of borehole trajectory anti-collision monitoring and reduce the risk of borehole collision, this method features high efficiency in collision prevention analysis and accurate collision prevention analysis results, making it an essential component of real-time collision prevention analysis for wellbore trajectory drilling. The study focuses on the analysis of two wells in a formation in the Sichuan-Chongqing region. Results indicate that in the well section at a depth of 597 meters, the separation coefficient is less than 1.5, suggesting a significant collision risk between the two wellbores. In this paper, the ISCWSA (Industry Steering Committee for Wellbore Survey Accuracy) error model, based on the borehole error theory and the calculation method of separation coefficient, combined with the real-time data acquisition of borehole trajectory, is used to form the real-time error analysis and anti-collision evaluation method of cluster well trajectory, which provides an effective technical means for realizing real-time anti-collision monitoring of trajectory while drilling. It is an important link in digital drilling, and it also puts forward an important method for intelligent decision analysis of intelligent drilling trajectory in the future.
Dynamics modeling and analysis of a down-hole drill string multibody system based on the absolute coordinate formulation
Authors: Fang Chao , Li HaiQuan , Liu Wei , Xu ZhaoHui , Liao MaoLin , Fan JinChao , Lin ZiLi , Pang HaiBo 
Published: December 2024

Abstract
Drilling system dynamics is the basis of studying the interaction between components in drilling process, which needs to solve many difficult problems such as geometric nonlinear dynamics of drill string, contact between drill string and wellbore, solving timeliness and so on. The existing research on establishing dynamic unit of local drilling tool structure has low solution efficiency, and it is difficult to meet the requirements of directional trajectory control and drilling speed increase analysis efficiently. Dynamics model of a downhole drill string system is established by using the multibody system dynamics method in this study. The natural coordinate formulation and the absolute nodal coordinate formulation are adopted to describe the rigid parts and the flexible beams, respectively. The presented model can be used to analyze the dynamic characteristics of the drill string system and the interaction between the drill string and the environment such as the wellbore and rocks in the drilling process. Finally, through comparative analysis with on-site test data, the correctness of the multibody dynamic model of the drill string system established in this paper was preliminarily verified.
Analysis of the coupling coefficient in non-contact magnetic couplers for rotary steering systems
Authors: Hou Shugang , Qiu Jun , Wang Huaping , Liu Naipeng , Wang Maokun , Liu Shiying 
Published: December 2024

Abstract
The coupling coefficient of the magnetic coupling mechanism is a critical parameter in the non-contact energy transmission technology used in rotary steering systems. To design a high-efficiency, high-performance magnetic coupling mechanism, this study examines the effects of movement, rotation, well deviation, and the number of magnetic cores on the coupling coefficient of the primary magnetic coupling mechanism. This analysis is based on a three-dimensional finite element model that has been experimentally validated. The method can reduce the design time of rotary steering systems, minimize potential issues during engineering implementation, and enhance economic efficiency. Simulation results show that the movement of the magnetic coupling mechanism has the most significant impact on the coupling coefficient, which drops sharply from 92.7% to 19.7%. The rotation effect on the coupling coefficient is minimal, with the coefficient remaining above 92.2%. Additionally, increasing the number of magnetic cores leads to a higher coupling coefficient. The simulation model demonstrates good agreement with the measured results, providing a theoretical foundation for designing magnetic coupling mechanisms and offering valuable insights for developing rotary steering systems in downhole measurement instruments.
Investigating the transverse jitter in ultrashort electron beam generation with optical compression
Authors: Li J. , Xu X. , Guo Z. , Zhang J. , Zhang H. , He Z. 
Published: December 2024

Abstract
Optical compression scheme is a highly potential candidate
for the generation of ultrashort electron beam. This scheme utilizes
a tightly focused radially polarized laser to compress the electron
beam from the photocathode radio frequency (RF) gun. However, the
unavoidable relative transverse jitter between the electron beam and
the modulation laser leads to a performance degradation of the
compressed pulse duration. To address this issue, we propose a
method for correcting this transverse jitter through a specific
design of optical system and an optimized decoupled solenoid. This
method concentrates on the transverse jitter caused by the pointing
instability of the laser. Its objective is to align both the
transverse jitter direction and magnitude of the modulation laser
with that of the electron beam. The simulation results demonstrate
that the deleterious impact of transverse jitter can be effectively
mitigated by this method, thereby ensuring the sustained generation
of high-quality ultrashort electron beams.
Nutrition-sensitive climate risk across food production systems
Authors: Tigchelaar Michelle , Selig Elizabeth R , Sarhadi Ali , Bruce Janaya , Allison Edward H , Battista Willow , Fanzo Jessica , Kleisner Kristin M , Mehrabi Zia , Naylor Rosamond L , Schmidhuber Josef , Thilsted Shakuntala H 
Published: December 2024

Abstract
Global nutrition targets remain unmet, as over half of preschool-aged children and two-thirds of non-pregnant women of reproductive age worldwide suffer from micronutrient deficiencies. Climate change poses a growing threat to global food and nutrition security, but existing climate risk assessments often overlook the critical roles of both terrestrial and aquatic nutrient-rich foods that are vital for dietary diversity and micronutrient supply. In this study, we introduce an innovative framework that integrates data on future climate extremes, nutrient supply dependencies, and diet-related climate vulnerability. Our comprehensive analysis assesses nutrition-sensitive climate risk to five essential micronutrients across production systems. By mid-century (2041–2060), we estimate that 75% of calcium, 30% of folate, 39% of iron, 68% of vitamin A, and 79% of vitamin B12 produced in primary food products will face frequent climate extremes (at least every other year) globally. Nearly fifty countries are projected to face high domestic climate risk for two or more micronutrients during this period, with ten countries facing high risk across all five. We outline distinct climate risk profiles to offer data-driven entry points into strategies for bolstering the resilience of micronutrient supply chains and advancing progress toward global nutrient targets in the face of a changing climate.
Corrigendum: Wave function collapse equation maintains conservation laws with no new constants (2023 J. Phys. A: Math. Theor. 56 355303)
Authors: Gillis Edward J 
Published: December 2024

Abstract
Gillis (2023 J. Phys. A: Math. Theor.
56 355303) proposed a modification of the Schrödinger equation with additional stochastic terms that would result in wave function collapse in accord with the Born probability rule. It was based on the hypothesis that collapse is induced by the entangling interactions that generate correlations between physical systems. It differed from earlier stochastic collapse proposals in that it was completely consistent with conservation laws and did not require the introduction of any new, ad hoc physical constants. In particular, it eliminated the need for a new constant determining the rate at which collapse proceeds by defining variable parameters tied to the rate of variation of the potential energy characterizing the interaction. Some technical problems with that definition were later pointed out to the author. Specifically, the definition used a time derivative in the numerator of the rate parameters, but time derivatives are not well defined in stochastic differential equations. The denominator in the rate parameter was defined as the expectation value of the maximum of the absolute value of the interaction potential energy, but the expressions used were not sufficient to accurately project this value. Both of these problems are corrected in this note. Because the specific definition of the new parameters was given in the appendix to the original paper, that appendix should be replaced as indicated in the body of this note. The main argument of the paper is not affected by these technical changes.
Influence of fluid properties and model parameters with regard to stratified gas-liquid gap flows
Authors: Burchardt L , Vorspohl J , Sabozin F , Meinke M , Schröder W , Brümmer A 
Published: December 2024

Abstract
In rotary positive displacement machines - like twin-screw compressors - clearance flows have a big impact on the quality of the energy conversion. To partially seal the gap connections and thereby reduce internal losses, an auxiliary fluid, e.g. oil, is often injected into these machines. If a chamber model method is used to simulate the thermodynamic operating behavior of such a wet-running twin-screw machine, two-phase mass flow rates through the gaps must be calculated as accurately as possible in order to achieve a high simulation accuracy. This paper presents an extended model for simulating such two-phase gap flows. The model allows the simulation of a gap flow, taking into account the possible outgassing of a gas (e.g. refrigerant) from a liquid phase (e.g. oil) along the gap. The model is used to analyse the influence of various fluid properties (e.g. solubility, density, viscosity) or boundary conditions (e.g. pressure ratio, quality at the inlet of the gap) in relation to the simulated gap mass flow rate.
On Rotor Profling of Internally Geared Screw Machines
Authors: Lacevic H , Kovacevic A , Stosic N , Read M 
Published: December 2024

Abstract
The internally geared screw machine represents a novel type of positive displacement compressor which consists of an inner and outer rotor. Both rotors rotate in the same direction but are each centered on offset parallel axes. The rotor profiles are designed to create multiple continuous contact points between the rotors, forming several separate working chambers whose volumes vary from minimum to maximum and back to minimum during a single rotation of the outer rotor. For a gas or two-phase working fluid, adjusting the discharge port geometry allows internal compression to occur before discharge. Previous research has focused on using the well-known rotor profling method, which employs a circular pin to generate the inner and outer rotor profiles. Although the rack method for rotor profile generation has been described and investigated for conventional screw machine rotor profiles, it has never been applied to internally geared screw machine profile generation. This paper provides an initial description and application of the rack method for generating internally geared screw machine profiles. Potential benefits of using the rack method compared to conventional methods for rotor profile generation in internally geared machines are discussed. Additionally, the limitations of using the rack method for internal gearing are presented and illustrated through various examples and applications.
OilMixProp 1.0: Package for Thermophysical Properties of Oils, Common Fluids, and Their Mixtures
Authors: Yang X , Richter M 
Published: December 2024

Abstract
This work presents the first version of OilMixProp (short for oil mixture properties), which could be the first software package capable of calculating all the core thermophysical properties of fluids involving user-defined oils. Properties needed in thermodynamic cycle analysis are all included: density, phase equilibria, heat capacity, entropy, enthalpy, speed of sound, viscosity, and thermal conductivity. Approximately 632 pure fluids are available, and users can define their oil by determining its fluid constants using embedded fitting tools. Analogous to refpropm (Matlab interface of REFPROP 10.0), a function OilPropm is developed as the only interface for calculating thermophysical properties. Various input combinations (e.g., temperature and pressure, pressure and enthalpy, temperature and vapor fraction, etc.) are available to cater to the needs of thermodynamic cycle analysis. Sophisticated outputs are designed to deliver either complete information (phases and properties in each phase) or selected information about a fluid at the given condition. The package is written in Matlab and will be converted to other languages (e.g., C++) in the future.
One-dimensional investigations of the periodic liquid-injection in twin-screw compressors
Authors: Heselmann M , Monden T , Brümmer A 
Published: December 2024

Abstract
The injection of liquid fluid (mostly oil) in twin-screw machines brings several advantages like sealing the gaps, at least partially, and absorbs some of the compression heat. To predict the machine behavior, it is essential to consider the injection process, because it determines the amount of liquid within the working chambers. This in turn determine the absorption of compression heat, the degree of sealing the gaps and the hydraulic losses. Therefore, in this study the transient liquid injection is investigated using a one-dimensional method of characteristics within the injection nozzle. The theoretical results are compared with the actual liquid mass flow rate of an oil-injected twin-screw compressor.
A Bayesian-interference approach to quantify degradation parameters in a water-cooled variable speed screw compressor chiller
Authors: Hoess A J , Ma J , Groll E A , Braun J E , Ziviani D 
Published: December 2024

Abstract
Variable-speed screw chillers can provide effective capacity modulations in commercial buildings to reduce energy consumption, match the load requirements, and contribute to lower equivalent carbon emissions. However, variable-speed operation can also yield to degradation phenomena inside the compressor. Assessing the real-time health status of chillers and detecting anomalies are important aspects to ensure long-term operation and improve reliability. To this end, an automated accelerated life test (ALT) procedure was developed and applied to a 513 kW (145.9 RT) water-cooled variable-speed screw chiller in a laboratory test facility to experimental assess performance degradation over time. After every 1,000 operating hours of ALT, steady-state performance tests at 30%, 50%, 75% and 100% load were conducted according to AHRI Standard 550/590. Additional operating conditions were included while conducting the tests to provide a more complete assessment of the degradation trends compared to the initially measured baseline. The experimental data set was then used to quantify the performance degradation based on the impact on the screw compressor operation. A Bayesian-inference identification approach has been developed to identify changes of sensitive parameters that statistically provide evidence for the likelihood of a performance degradation of the compressor. The information was used to implement the parameters in a dynamic model which was used to perform studies to predict the degradations of a chiller. The outcomes of this study help to improve the maintenance schedule of a compressor and even the whole chiller so that the system can be operated more economically and unplanned downtime can be minimized.
MoS2 Coatings in unsynchronized, dry-running Screw Compressors: Experimental Insights on Operational Efficiency and Durability
Authors: Geissendorf M , Aurich D , Spraffke B , Lopes Dias N F , Tillman W , Nicolai S , Debus J , Brümmer A 
Published: December 2024

Abstract
The discourse on unsynchronized, oil-free screw compressors versus their conventional, oil-lubricated counterparts encapsulates a pivotal shift towards more effi-cient and environmentally friendly industrial machinery. By forgoing gears and lubricants, these innovative compressors streamline manufacturing and assembly, while also eliminating the risk of lubricant contamination in the process gas. In this configuration, the torque generated on the gate rotor by the gas pressure is directly conveyed to the main rotor through the interfacing surfaces of the rotors. In the development of compressor technology, a significant improvement is the application of a molybdenum disulfide (MoS2) coating on the primary rotor. This application utilizes the properties of molybdenum disulfide, which is effective in reducing friction and wear under various operational conditions. By applying this coating, there is an anticipated increase in the wear resistance of the rotor, effectively reducing frictional losses during its operation. This reduction in friction is expected to improve the mechanical efficiency of the compressor and extend its operational lifespan. The investigation of contact interactions utilizes a custom-designed test rig, through which effective parameters are analyzed to facilitate conclusions regarding losses and the durability of the coating. Additionally, the geometry within the contact area is tactilely measured, enabling the quantitative determination of wear. Various layer thicknesses, surface roughness levels, and loads are examined in this context.