Rig System Research Articles

Comparison of three different ice hockey helmets using an ice hockey specific test protocol

Although there are currently no standard tests measuring rotational head motion for ice hockey, researchers have proposed test methods which induce rotational head motion from an impact and may reflect more closely how concussions occur in the sport. Recently, Meehan et al. developed a test method for ice hockey helmets to represent concussive injuries associated with ice hockey. While that provided a method that used impact parameters closer to what may be experienced, the research did not evaluate if different helmets would produce differing results under those loading conditions. The purpose of this study is to use the methods developed by Meehan et al. to evaluate the protective capacity of three different ice hockey helmet designs. This research used monorail drop rig and pneumatic ram systems to follow the protocol of Meehan with a bare headform condition and three different helmet designs, allowing for differences in linear and rotational acceleration, rotational velocity, and maximum principal strain to be determined. The results of this research found that the test method developed by Meehan et al. does result in significant differences between different helmets and helmet designs under identical impact conditions. However, these differences were limited which may be a reflection of the test method as well as commonality in terms of how ice hockey helmets are designed; the different models may not be sufficiently different enough to provide different results under these loading conditions.

Withdrawal Capacity of a Novel Rigging Device for Prefabricated Wood I-Joist Floor Panels

Prefabricated wood construction relies heavily on efficient material handling, yet rigging system design for floor panels remains understudied. This study introduces a novel rigging device that attaches to prefabricated wood I-joist floor panels using self-tapping screws, avoiding potential damage caused by predrilled holes in the sheathing panels and framing members. To establish allowable lifting capacities and optimal installation practices, comprehensive withdrawal tests were conducted on 114-floor panel specimens. Factors influencing withdrawal capacity, such as anchor plate placements, flange materials and width, screw type and quantity, and sheathing panel thickness, were systematically evaluated. Results indicate that withdrawal capacity does not scale linearly with screw quantity and that anchor plates with eight screws centered on the flange enhance performance by up to 20% compared to four-screw configurations. Unexpectedly, thinner sheathing panels yielded higher capacities, potentially due to increased screw penetration depth in the joist flange. In addition, anchor plate orientation, flange width, and flange materials also impact capacity. These findings provide essential data for designing reliable and efficient rigging systems in prefabricated wood construction.

Nitroquinolone Fused Salicyl and Naphthyl Hydrazone Fluorescent Probes for the Detection of Fe3+and Pb2+ Ions.

The application of quinolones stretches over a large umbrella of medicinal field as well as chemosensor due to the presence of privileged heterocyclic aromatic rig system. Salicyl and Naphthyl Hydrazide motifs are also established fluorophore groups. Therefore in this work, we have designed and synthesized Salicyl hydrazide (3a-c) and naphthyl hydrazide fused nitroquinolones (5a-c) investigated for their fluorescent behaviour. Preliminary UV- absorption studies were carried out and the metal selectivity were examined with various metal ion. Among them, it was found that compound 3a was selective towards Fe3+ ions (λex = 330nm, 1:1 DMF:H2O at pH = 7.4 in HEPES Buffer medium). 3a shows decrease emission intensity in presence of Fe3+ ions. Compound 5a shows enhancement in fluorescence intensity upon addition of Pb2+ ion (λex = 280nm, 1:1 DMF:H2O at pH = 7.4 in HEPES Buffer medium). Further, the concentration dependence, competitive binding and EDTA reversibility were studied for selected compounds towards the respective cations selectivity. Jobs plot analysis indicate that 1:1 binding of 3a with Fe3+ ion (Ka = 3.17 x104M-1 and Limit Of Detection (LOD) = 5.1 × 10-7 M) whereas 5a showed 1:2 binding mode with Pb2+ ions (Ka = 2.14 × 106M-1 and Limit Of Detection (LOD) = 2.613 × 10-9M). Density Function Theoretical studies were performed as support for the experimental results.

Evaluation of the Degree of Degradation of Brake Pad Friction Surfaces Using Image Processing

The improvement of drilling rig systems to ensure a reduction in unproductive time spent on lowering and lifting operations for replacing drilling tools and restoring the performance of drilling equipment units is an important task. At the same time, considerable attention is paid to the reliable and efficient operation of the braking systems of drilling rig winches. In the process of operation, the polymer pads periodically come into contact with the outer cylindrical surface of the metal pulley during braking, work in extreme conditions and wear out intensively, so they need periodic replacement. Tests were carried out on a modernized stand and in industrial conditions for the brakes of drilling winches. A methodology for evaluating the degradation of the brake pad friction surface during its operation is proposed. The assessment of the degradation degree is carried out based on the image of the brake pad surface using image processing techniques. Geometric transformations of the input image were performed to avoid perspective distortions caused by the concave shape of the brake pads and the spatial angle at which the image is acquired to avoid glares. The crack detection step was implemented based on the scale-space theory, followed by contour detection and skeletonization. The ratios of the area and perimeter of segmented and skeletonized cracks to the total area were chosen as integral characteristics of the degradation degree. With the help of scanning electron microscopy, the character of the destruction of the friction surface and the degradation of the polymer material was investigated. Experimental studies were performed, and the application of the proposed method is illustrated.

Research on Micro-Turbine Operating State Characterization Based on Bearing Vibration Signals Analysis

An air flow-driven micro-turbine, widely used in air-condition control systems in aircraft cabins, train coaches, etc., exhibits complex vibration behaviors under stable or unstable inlet flow conditions, and especially has a certain correlation with speeds. In this paper, the vibration responses of the micro-turbine undergoing stable and unstable inlet flows measured on a test rig are analyzed and compared by using different signal processing methods, which include time and frequency domain methods, and statistical and nonlinear methods. First, the test rig system of the airflow-driven micro-turbine, the instrument system and four typical experimental cases are introduced. Then the measured vibration signals are analyzed and compared by time domain characteristic parameters (peak-to-peak value, RMS value and kurtosis value), statistical parameters (auto-correlation and BDS), and amplitude spectra in the frequency domain, statistic spectrum indicators (SSI) based on Welch's periodogram of power spectra, and the spectra of selected IMF components based on Hilbert-Huang Transform (HHT). In particular, some nonlinear feature analyzing methods, including Pseudo-Poincare mapping diagrams and Lempel-Ziv(LZ) complexity, are also used for analyzing measured vibration responses. The obtained results using the above multiple methods are compared and show that, when the inlet flow of the turbine fluctuates significantly, the nonlinear characteristics of the turbine bearings are significantly higher than those of the relatively stable inlet flow and speed conditions. Under these circumstances, commonly used time-frequency analysis methods cannot characterize the different speed operating state of the turbine, and LZ-Complexity and other nonlinear characterization methods should be used to better understand the characteristics of different speeds under unstable conditions.This study provides references for the aerodynamic stability monitoring of the micro-turbine and its design improvement.

Aerothermodynamic features of a Coriolis-applied smooth U channel for gas turbine blade

Rising temperature of gas turbine inlet brings great challenge for blade temperature tolerance, thus high effective cooling structure for turbine blade is vital. In this paper, aerothermodynamic features including heat transfer and pressure drop of a Coriolis-applied rotating smooth U channel are studied in detail. Both experiment and numerical methods are utilized in the study. A rotating cooling structure experiment rig system has been established and validated. The experiments were conducted in the rotating cooling structure experiment rig. Besides, RANS was chosen in the simulation. In the experiment and numerical studies, Reynolds number is constant at 16000 and Rotation number ranges from 0 to 0.024. The results indicate that Coriolis force plays a dominant and positive role on heat transfer ability on trailing wall, and that bend outlet impingement effect is the primary factor compared to Coriolis force for the Nusselt number of smooth leading surface. Besides, Coriolis force at bend region probably suppresses the formation of K–H vortices, thus boosts the flow stability, reduce pressure loss of channel and weakens second heat transfer peak of impingement at the bend outlet. What's more, the total performance of the Coriolis-applied smooth U channel at Ro of 0.006 and 0.024 are 2.18 % and 8.51 % higher than the channel at Ro of 0, which means that rotation is good for the Coriolis-applied smooth U channel and that the channel has superior performance and is encouraging in future rotating blade cooling application.

Railway Wheelset Active Control and Stability via Higher Order Neural Units

This article investigates an unconventional approach to solving the control of lateral displacement for railway bogie wheelsets using recurrent higher order neural units (HONUs). Although studies addressing control of independently rotating wheelsets have shown promising results, they are rarely applied by railway manufacturers. Research and developments in modern bogie design are trending toward active yaw control design as an extension to conventional wheelsets mechanics, particularly for higher speeds. We investigate a model-reference architecture for active control via setpoint tracking of lateral displacement. Then, a new HONU sliding mode architecture is derived to solve convergence for zero lateral displacements in higher running speeds which is a more profoundly complex issue in maintaining minimal hunting motion. Starting from the property of nonlinear polynomial architecture of HONUs with in-parameter linearity, we derive a time-variant state-space representation via nonlinear identical decomposition. Then, an input-to-state stability (ISS) approach is applied to prove the local asymptotic convergence of the applied algorithm in each state point and the bounded-input-bounded-state stability of the entire nonlinear adaptive control loop. Using ISS theory, we also prove the global asymptotic stability of the HONU sliding mode controller for the actively controlled wheelset system. The techniques are validated by simulations and a real roller rig system.

A Study on the Integrated FK Rigging System for Motion Graphics Character Motion

A Study on the Integrated FK Rigging System for Motion Graphics Character Motion

Harmonic Resonance Analysis of Shale Gas Distribution Network with Phased Load

Based on the background of achieving carbon peaking and carbon neutrality, the development and application of new high-power compressors, electric grid drilling RIGS and electric fracturing pump system provide new equipment support for the electric, green and intelligent development of shale gas fields in China. However, the harmonic pollution of shale gas grid becomes more serious due to the converter and frequency conversion device in the system, which easily causes harmonic resonance problem. Therefore, the harmonic resonance of shale gas grid is comprehensively analyzed and treated. Firstly, the working mechanism of compressor, electric drilling RIGS of the harmonic impedance model of electric fracturing pump system is established. Secondly, the main research methods of harmonic resonance analysis are introduced, and the basic principle of modal analysis is explained. Modal analysis method was used to analyze. Finally, harmonic resonance is suppressed. The results show that there may be multiple resonant frequency points in the distribution network changes, but these changes are relatively clear; if the original resonant frequency point of the resonant loop does not exist, the resonant frequency point disappears. The optimal configuration strategy of passive filter can effectively suppress harmonic resonance of distribution network in shale gas field.

Eros and Trumpism: A Marcusean Interpretation

An explanation for Donald Trump’s political appeal is developed, drawing mainly on Herbert Marcuse’s study Eros and Civilization. Trump does not represent the authority of a strong father-leader so much as filial rebellion. His rebellion against the father-rule, now transmuted into an impersonal “rigged system,” permits and even encourages the explosive release of suppressed sexual and aggressive drives. However, this release does not constitute the liberation of Eros that Marcuse envisioned. Instead, Trumpism explodes suppressed sexuality within the institutions of the performance principle, gives sadistic expression to the sexual drive, conditions the abolition of sexual taboos on the creation of new objects of humiliation, and turns a collectivized sense of guilt “against those who do not belong to the whole, whose existence is its denial.” In sum, Trumpism was a betrayed revolution from the beginning; what it really represents is the political utilization of sex and aggression to reinforce social domination.

Improvement of Dust Particle Suction Efficiency by Controlling the Airflow of a Regenerative Air Sweeper

In a regenerative air sweeper, airflow and dust particles entering the system are filtered and recirculated within the system. The uncirculated portion of the exhaust air in the system spreads to the ambient air, and PM2.5 dust in the air can poison the environment and adversely affect human health. The development of an airflow control system to reduce road dust emissions and improve air quality was the main contribution of this study. A regenerative air sweeper airflow control system is designed to direct the air from the centrifugal fan back into the pickup head to fully absorb the dust particles and balance the positive and negative air pressures inside the pickup head. The modeling and analysis of the dust control system were performed using an experimental test rig system. A mathematical model of the fundamental parameters of the regenerative air sweeper and dust control system was established. Computational fluid dynamics (CFD) ANSYS was used for the analysis to determine the direction of airflow via the suction and inlet ducts. The discrete particle model (DPM) accurately predicted particle trajectories and measured the suction efficiency of particles of different shapes and types. By controlling the circulating harmful air flow in the system, the amount of PM2.5 released into the atmosphere was reduced by 90%. The suction efficiency of the 200 μm sized sand particles was higher than 95%. The results provide theoretical and methodological assistance for the development of improved road sweeper dust control systems.

Analysis of a Lower Deck Rigging Configuration and Reusable Padeye Design based on Finite Element Model for Improving Stacking Operation Efficiency

In the topside fabrication process, the decks will be fabricated first simultaneously and then they will be arranged sequentially to form the topside through a stacking operation. The integrity of the deck structure must be maintained during and after the stacking process. The integrity of the deck structure and rigging system is strongly influenced by the design of the rigging system. Meanwhile, the design of the rigging system is limited to the equipment available to the company. So, it is necessary to analyze a proper rigging configuration with the existing limitations. In this case study, the rigging design and stacking analysis of the lower deck structure were carried out. From the analysis results, the 4 crane rigging configuration is used, with the highest crane utilization occurring on the crane is 89%. In the rigging system, the smallest safety factor on the sling is 1.17, and the shackle is 1.12, while on the deck structure the maximum UC is 0.32 and the maximum deflection that occurs is 2.17 cm. The reusable padeye UC is 0.53 in the numerical method analysis with a maximum von misses stress is 191 MPa which was concentrated at the lower end of the stiffener plate.

Character articulation through profile curves

Computer animation relies heavily on rigging setups that articulate character surfaces through a broad range of poses. Although many deformation strategies have been proposed over the years, constructing character rigs is still a cumbersome process that involves repetitive authoring of point weights and corrective sculpts with limited and indirect shaping controls. This paper presents a new approach for character articulation that produces detail-preserving deformations fully controlled by 3D curves that profile the deforming surface. Our method starts with a spline-based rigging system in which artists can draw and articulate sparse curvenets that describe surface profiles. By analyzing the layout of the rigged curvenets, we quantify the deformation along each curve side independent of the mesh connectivity, thus separating the articulation controllers from the underlying surface representation. To propagate the curvenet articulation over the character surface, we formulate a deformation optimization that reconstructs surface details while conforming to the rigged curvenets. In this process, we introduce a cut-cell algorithm that binds the curvenet to the surface mesh by cutting mesh elements into smaller polygons possibly with cracks, and then derive a cut-aware numerical discretization that provides harmonic interpolations with curve discontinuities. We demonstrate the expressiveness and flexibility of our method using a series of animation clips.

Analysis of the frequency deviation in off-grid power system of oil field

The paper represents the results of field measurements in the off-grid power system of oil field including diesel power plant, which supplies drilling rig system BU-4500/270 EK-BM. The data has been processed using the instantaneous power theory by Hirofumi Akagi. The active power load diagram of diesel power plant and power system frequency schedule have been obtained for hole drilling technological process of drilling rig. Abrupt load changes during drilling lead to large frequency deviations, which do not allow using gas piston generators in power system of oil field without revision of number and rated power of generators or using electrical energy storage system.

A Robotic Test Rig for Performance Assessment of Prosthetic Joints.

Movement within the human body is made possible by joints connecting two or more elements of the musculoskeletal system. Losing one or more of these connections can seriously limit mobility, which in turn can lead to depression and other mental issues. This is particularly pertinent due to a dramatic increase in the number of lower limb amputations resulting from trauma and diseases such as diabetes. The ideal prostheses should re-establish the functions and movement of the missing body part of the patient. As a result, the prosthetic solution has to be tested stringently to ensure effective and reliable usage. This paper elaborates on the development, features, and suitability of a testing rig that can evaluate the performance of prosthetic and robotic joints via cyclic dynamic loading on their complex movements. To establish the rig’s validity, the knee joint was chosen as it provides both compound support and movement, making it one of the major joints within the human body, and an excellent subject to ensure the quality of the prosthesis. Within the rig system, a motorised lead-screw simulates the actuation provided by the hamstring-quadricep antagonist muscle pair and the flexion experienced by the joint. Loads and position are monitored by a load cell and proximity sensors respectively, ensuring the dynamics conform with the geometric model and gait analysis. Background: Robotics, Prosthetics, Mechatronics, Assisted Living. Methods: Gait Analysis, Computer Aided Design, Geometry Models. Conclusion: Modular Device, Streamlining Rehabilitation.

Dilemmas of Immigrant Asylum Claims for Expert Witnesses

AbstractExpert witnesses are key players in immigration asylum proceedings. In many cases, their testimony is the difference between prompt deportation and some form of relief. However, political and economic structures overdetermine the factual and legal dimensions of immigrant asylum claims. The U.S. immigration system from its inception has been heavily politicized and discriminatory. The problem has become even more pronounced since the election of Donald Trump as president. This article examines political, economic, and ethical dilemmas of immigrant asylum claims for expert witnesses. These include issues related to the caliber of judges and lawyers, the geographic location of legal proceedings, challenges of telephonic versus in‐person testimony, moral questions regarding whether to participate in a rigged system, the weight given to expert opinions, unrealistic standards of evidence, obstacles to the presentation of social scientific data, and expert witness burnout.

Event-Triggered Control for Networked Systems Under Denial of Service Attacks and Applications

In this paper, the resilient controller design and synthesis issues of networked control systems under denial-of-service (DoS) attacks are investigated via an adaptive event-triggered strategy. In a networked control system, DoS attacks have serious impacts on the security of communication, possibly causing degraded stability performance of the system. To remove threats from DoS attacks, an adaptive event-triggered communication mechanism is proposed, which also provides benefits in reducing the consumption of communication resources and relieving the pressure on network bandwidth. Since the system state information is usually not fully known, an observer-based controller is developed to stabilize the system and maintain a desired performance index despite the occurrence of stochastic attacks. Furthermore, a joint design method is proposed to obtain the controller gain, observer gain and event-triggered weight matrix. Finally, practical examples based on a four-tank system, an Internet-based three-tank system and an Internet-based test rig system are presented to illustrate the effectiveness of the proposed techniques to respond and eliminate the impact of DoS attacks.

Performing Work: Maids, Melodrama, and Imitation of Life as Film Noir

In this article I argue that Douglas Sirk’s maternal melodrama, Imitation of Life (1959), advances an ideology whereby Black women are equated with and consigned to domestic labor. The film features two mother-daughter pairs, one Black and one white. The Black mother, Annie, works as a maid for the white mother. Annie’s light-skinned daughter, Sarah Jane, passes as white to avoid following her mother’s condition. But Annie’s death at the film’s end seems to bring a contrite Sarah Jane back to her subservient place in the white family. I consider Imitation in relation to nineteenth-century traditions of racial melodrama and current theories of Black materialism to trace how US labor practices worked with discursive systems such as the movies to make the “Black maid” ubiquitous and the modifier unnecessary. Moreover, the structural inequality that relegates Black women to service requires them to act as if they are free agents within a rigged system: that is, to perform an imitation of life. However, the Black characters seize agency from a scopic economy of pleasure founded on Black women’s embodied pain and labor. The emotional power of Annie’s funeral, heightened by Mahalia Jackson’s performance as choir soloist, appropriates melodramatic sentimentality and subverts Sirk’s intended irony to convey Annie’s value on a different scale. Sarah Jane’s protest through passing registers despite her capitulation after Annie’s death because Sirk’s technique for criminalizing her backfires. The film weaves elements of noir, including striptease, into the visual register to construct her as a dangerous femme fatale. But Sarah Jane inverts the narrative’s attempt to strip away her whiteness by making Black servitude the costume, not the essence. Thus, she destabilizes the racial binaries asserted by the tragic mulatta conventions. By theorizing Black agency in scripted performance, revealing Imitation’s hybrid genre of melodrama noir, and reconsidering representations of Black women’s labor, this essay contributes to work in Black materialism and Black feminist performance studies.

A High-Speed Disk Rotor Rig Design for Tip Aerothermal Research

Abstract The relative casing motion can greatly vary the over-tip-leakage (OTL) flow structure and aerothermal performance. The existing tip experimental research facilities including stationary linear cascade, cascade rigs with low-speed moving belt, or high-speed rotor rigs are either not capable of reproducing the high relative casing Mach number or extremely expensive and still difficult for optical measurement. This paper presents a high-speed disk rotor design that can simulate the high casing relative speed. The unique feature of this rig design concept is that it enables full optical access of the tip surface under the engine-representative OTL flow condition. In this paper, the feasibility of the design concept is demonstrated and assessed by Reynolds-averaged Navier–Stokes computational fluid dynamics (RANS CFD) simulation, both in component level and in whole rig system level. First-of-its-kind experimental results of spatially resolved tip heat transfer coefficient distribution at high relative casing Mach number are reported. The disk rotor rig design demonstrated in this paper can also be useful for other tip leakage flow studies.

‘As good as a chorus’: Hamlet’s Mousetrap in philosophy and psychoanalysis

ABSTRACT A great part of Hamlet’s mystery resides in the Mousetrap. Its role is fundamental for the tension of the play, yet its importance extends beyond that. Philosophers and psychoanalysts alike have been fascinated by it. The former have underlined its epistemological aspects and capacity for self-reflection: its power to mirror reality and reveal something new. The latter have placed weight on its ‘primal scene’ character and have underlined its failure to move Hamlet to act. Here I explore the paradox that results from putting philosophy and psychoanalysis together. To illustrate its functions, as well as the different readings of it, I delve into certain moments of the scene and Hamlet several times. Expanding on some remarks made by Lacan about the Mousetrap, I contend that it is a ‘rigging system’, a highly complex mise-en-abyme structure and intersubjective complex unfolded over successive layers. This explains the self-reflectivity discerned by philosophers. Following Benjamin and Lacan, and by means of a detour through Schmitt, I argue at the end that its failure needs to be situated in the historical moment when it was created – a world characterised by the lack of transcendent values – one in which art folds back upon itself infinitely.