Internal Valve Research Articles

Performance Characteristics of a Compact Core Annular-Radial Magnetorheological Damper for Vehicle Suspension Systems

The magnetorheological (MR) damper is a by-wire system capable of providing variable damping stiffness by responding to an apparent magnetic field. In response to the magnetic field application, the magnetorheological fluid (MR fluid) exhibited altered behavior within the damper. Typically, a damper’s internal and external valves operate in flow mode, where the flow is regulated by controlling the magnetic field. This study aims to investigate the performance characteristics of a small core annular and radial magnetorheological valve (SCARMV) designed for applications in vehicle suspension systems. The proposed design of the simplified MR valve is based on a meandering-type valve composed of multiple valve cores that have been simplified to a single core. Dynamic testing was performed on the proposed valve, which features a single rod tube damper, to investigate the damping force characteristics by varying currents and frequencies. The characteristics of the measured damping force were compared to the calculated damping force based on the pressure drop calculation and the FEMM simulation of magnetic flux. By increasing the stroke length of the valve travel is set to 10 mm at a current input of 0 A to 1.0 A, the maximum output of the MR valve damping force was approximately 1.57 kN. In addition, a mathematical model of SCARMV is presented and compared to the experimental data. Therefore, based on the experimental results, it was concluded that the usability of a compact core MR valve is reliable. However, more in-depth studies are required before these dampers can be applied to vehicle suspension systems.

Static and Thermal Analysis of Internal Combustion Engine Valves

Abstract: In this paper the 3D model of the internal combustion engine valves was realized using Autodesk Inventor Professional 2024 and finite element analysis, static and thermal was performed, in order to determine the state of stress, deformation and temperature evolution, by applying restrictions and loads conditions. Two materials were chosen, for internal combustion engine valves, in accordance with the specialized literature. The materials taken for static and thermal analysis was Stainless Steel AISI 446 and NiCr0TiAl. Following the comparative study for the two models, it can be specified the importance of the material for the construction of the internal combustion engine valves who depends on the material properties and their design.

MORPHOLOGICAL VARIATIONS IN MUD CLAM Polymesoda erosa (Lightfoot) USING FLUCTUATING ASYMMETRY ANALYSIS IN LA UNION, CABADBARAN CITY, AGUSAN DEL NORTE, PHILIPPINES

A geometric morphometric study was conducted on the population of Polymesoda erosa in La Union, Cabadbaran City, to investigate the morphological variations using fluctuating asymmetry (FA) analysis. FA acts as a reliable indicator of ecological stress and developmental instability since it detects genetic or environmental changes that an organism experiences. A total of ninety (90) individual mud clams were randomly collected and analyze. Water and soil samples were also collected to gather data on the degree of body variations and the impact of external factors on P. erosa. The result of the analysis using the SAGE software revealed a highly significant fluctuating asymmetry (P 0.0001). Significant variations in individuals, sides, and the interaction between individuals and sides symmetry were mostly responsible for the substantial variances seen in mud clam species. Particularly, landmarks 10 (dorsal margin maxima) and 13 (anterior margin maxima) exhibited notable variations. For the water quality results, the mud clam's internal valve was likely to be relatively unaffected or minimally impacted, but the level of nickel was high. In conclusion, the fluctuating asymmetry of P. erosa can be attributed to a stressed environment. Unfavorable environmental factors cause an organism's morphology to change, affecting its symmetry.

Analysis of different objective functions in petroleum field development optimization

Oilfield development optimization plays a vital role in maximizing the potential of hydrocarbon reservoirs. Decision-making in this complex domain can rely on various objective functions, including net present value (NPV), expected monetary value (EMV), cumulative oil production (COP), cumulative gas production (CGP), cumulative water production (CWP), project costs, and risks. However, EMV is often the main function when optimization is performed under uncertainty. The behavior and performance of different objective functions has been investigated in this paper, when EMV is the primary criterion for optimization under reservoir and economic uncertainty. One of the goals of this study is to provide insights into the advantages and limitations of employing EMV as the sole objective function in oil field development decision-making. The designed optimization problem included sequential optimization of design variables including well positions, well quantity, well type, platform capacity, and internal control valve placements. A comparative analysis is presented, contrasting the outcomes obtained from optimizing the EMV-based objective function against traditional objective functions. The study underscores the importance of incorporating multiple objective functions alongside EMV to guide decision-making in oilfield development. Potential benefits in minimizing CGP and CWP are revealed, aiding in the mitigation of environmental impact and optimization of resource utilization. A strong correlation between EMV and COP is identified, highlighting EMV’s role in improving COP and RF.

Research on internal leakage detection of the ball valves based on stacking ensemble learning

Abstract Natural gas is an important clean energy source that is mainly transported through pipelines. The ball valve is a crucial piece of control equipment for the pipeline transportation system for natural gas, and the failure of internal leakage of the ball valve will seriously affect the natural gas transmission and increase the risk of sudden safety accidents. In response to the problems of the limitations of a single machine learning model in the traditional ball valve internal leakage rate prediction methods and failure to qualitatively analyze unilateral and bilateral internal leakage recognition of ball valve, a study of ball valve internal leakage detection based on Stacking ensemble learning is proposed. A total of 15 time and frequency domain feature parameters were obtained by feature extraction of 125 and 96 sets of raw acoustic emission signals from the ball valve; the parameters of a single machine learning model were adjusted by Bayesian optimization grid search. An internal leakage rate prediction model and an internal leakage recognition model are constructed, and the proposed model is compared and analyzed with a single model through a field ball valve internal leakage test. The results indicate that the Stacking ensemble learning model outperforms each single machine learning model in terms of SMAPE (17.2583), RMSE (1.1009), and MAE (0.9375) for internal leakage rate prediction. The Stacking ensemble learning model outperformed the single machine learning model in terms of accuracy (1), recall (1), precision (1), FAR(0), and F1-score (1) for internal leakage recognition. Stacking ensemble learning significantly enhances the model's ability to detect internal ball valve leaks.

Analysis of tribological aspects during operation and repair of internal combustion engine valve mechanism parts

Analysis of tribological aspects during operation and repair of internal combustion engine valve mechanism parts

Management of Nasal Valve Dysfunction.

Nasal valve dysfunction can substantially impact nasal airflow and overall quality of life. This review provides a comprehensive examination of nasal valve dysfunction, including its mechanisms, classification, and surgical management. The nasal valves include internal and external valves, each of which plays a crucial role in regulating nasal airflow. Subclassification of the external nasal valve into alar and rim valves helps specify the site of obstruction when present and informs the choice of surgical intervention. Dynamic nasal valve obstruction, often characterized by inspiratory collapse of the nasal valve, must be distinguished from static obstruction, which refers to nasal valve stenosis. Accurate identification of the location and mechanism of nasal valve dysfunction is essential for effective management. Various surgical procedures target specific components of the nasal valve and can produce favorable functional outcomes. The selection of surgical procedures, whether individually or in combination, should be tailored to the characteristics of nasal valve dysfunction and the external nasal characteristics of the patient. Strict adherence to proper surgical techniques is imperative for achieving optimal treatment outcomes.

Analysis of the valve positioner pilot valve hole plugging

The valve positioner is an important supporting component of the regulating valve. The pilot valve is a crucial component of the valve positioner, and its major job is to reverse the gas route. The current lack of efficient solutions for internal pilot valve blockage is due to the unavoidable oil loss inside the positioner and the simple entry of external dust and other contaminants into the valve, resulting in oil blockage inside the pilot valve. The fault tree theory is utilized in this study to evaluate the reason of the pilot valve blockage problem, and it is coupled with 39 engineering factors in TRIZ theory to innovate the internal structure of the pilot valve using a contradiction matrix and 40 invention principles. The product’s dependability was then confirmed by fluid analysis using Ansys fluent.

Effective orifice diameter: a new sizing parameter of surgical valve prostheses to inform valve selection.

The labeled sizes of surgical valve prostheses and their discordance with the physical internal valve orifice sizes has long been a controversy in the cardiac surgery community, leading many to believe it to be a contributing factor in prosthesis-patient mismatch following valvular replacement surgery. In an attempt to address this issue, the International Organization for Standardization (ISO) 5840-2:2021 standard for surgical valve prostheses recommends that a new sizing parameter, namely, the effective orifice diameter, be provided in labeling by all manufacturers as an indicator of the true flow-passing capacity of a prosthetic valve. The ISO Cardiac Valves Working Group conducted a multi-laboratory round-robin study to investigate whether the effective orifice diameter of a prosthetic surgical valve could be derived repeatably and reproducibly through steady forward-flow testing. A total of seven valve models, each with multiple sizes, were tested, including a mechanical heart valve and multiple biological heart valves. The round-robin study confirmed that the steady forward-flow test had good intra-laboratory repeatability and inter-laboratory reproducibility in deriving the effective orifice diameters of surgical valve prostheses. On average, among the participating laboratories, the experimentally derived effective orifice diameter of a prosthetic heart valve was 3-12 mm smaller than its labeled size. The effective orifice diameter provides better characterization of the hydrodynamic characteristics of a surgical valve prosthesis and can be derived using a validated steady forward-flow test method. This new sizing parameter will soon be adopted by surgical valve manufacturers and provided in device labeling to inform valve selection by surgeons.

Development of Novel Hydraulic 3D Printed Actuator Using Electrorheological Fluid for Robotic Endoscopy

Endoscopy has made a significant and noteworthy contribution to the field of medical science and technology. Nevertheless, its potential remains constrained due to the limited availability of rigid or flexible endoscopes. This paper introduces a novel hydraulic actuator based on electrorheological fluid (ERF) as a pivotal advancement in bridging the existing gap within the realm of endoscopy. Following a comprehensive introduction that briefly outlines the electrorheological effect, the subsequent section is dedicated to the elucidation of the actuator’s development process. Challenges arise, particularly in terms of miniaturization and the realization of a hydraulically sealed system with integrated valve electrodes. An internal electrorheological valve system consisting of four valves that are controlled using a pulse-width modulated high voltage was suitable for position control of the antagonistic hydraulic actuators. High-precision stereolithography (SLA) printing has proven practical for manufacturing actuator components. For functional testing, a test bench was set up in which the actuator follows a setpoint through a PI control loop. The control deviation ranged from 0.6 to 1 degree, with a response time between 6 and 8 s. The experiments have demonstrated that through the use of ERF and integrated valve electrodes, a miniaturized functional actuator can be constructed.

METHODOLOGY FOR STUDYING ACCURACY PARAMETERS
 IN THE PROCESS OF RESTORING THE VALVE SEATS

In this article a methodology for researching the parameters of forming in the process of processing valve seats
 of an internal combustion engine valve timing gear in an automobile repair industry was described.
 The practical implementation of this methodology was carried out using laser triangulation sensors based on the
 developed device for boring valve seats. Experimental dependences of the cutting tool displacement on various processing modes were obtained. Practical recommendations were made on the selection of cutting mode ranges to ensure
 the required precision parameters when restoring valve seats.

The Ongoing Debate: Longevity of Biological Valves in Pulmonary Position.

In patients with tetralogy of Fallot (ToF) or ToF-like anatomy, factors possibly impacting the longevity of biological valves in the pulmonary position were investigated. Between 1997 and 2017, 79 consecutive hospital survivors with a median age of 8.7 years (range: 0.2-56.1 years; interquartile range [IQR]: 14.8 years) with ToF or ToF-like anatomy underwent surgical implantation of Contegra (n = 34), Hancock (n = 23), Perimount (n = 9), pulmonary homograft (n = 9), and miscellaneous (n = 4) conduits. The median internal graft diameter was 19 mm (range: 11-29 mm; IQR: 8 mm) which refers to a median z-score of 0.6 standard deviation (SD) (range: -1.8 to 4.0 SD; IQR: 2.1 SD). The median time of follow-up was 9.4 years (range: 1.1-18.8 years; IQR: 6.0 years). Thirty-nine patients (49%) underwent surgical (n = 32) or interventional (n = 7) pulmonary valve re-replacement. Univariate Cox regression revealed patient age (p = 0.018), body surface area (p = 0.004), internal valve diameter (p = 0.005), and prosthesis z-score (p = 0.018) to impact valve longevity. Multivariate Cox regression analysis, however, did not show any significant effect (likely related to multicollinearity). Subgroup analysis showed that valve-revised patients have a higher average z-score (p = 0.003) and younger average age (p = 0.007). A decreased longevity of biological valves in the pulmonary position is related to younger age, lower valve diameter, and higher z-score. Because valve size (diameter and z-score) can be predicted by age, patient age is the crucial parameter influencing graft longevity.

Improving the mode of induction surfacing of reinforcing rings on internal combustion engine valves made of austenitic steel.

Improving the mode of induction surfacing of reinforcing rings on internal combustion engine valves made of austenitic steel.

Investigation of laser remelting of hardening rings of internal combustion engine valves.

Investigation of laser remelting of hardening rings of internal combustion engine valves.

The Importance of Appropriate PAP Silicone Mask Selection in Sleep Apnea Management

Positive airway pressure (PAP) is the standard treatment for patients with moderate to severe obstructive sleep apnea, especially when a correctable anatomic obstacle is not identified. The PAP efficiency strongly depends on the appropriate use during sleep. Despite the recent advancements in PAP interface designs, overall adherence to therapy remains low. The main sources of discomfort consist of air leakage and mask overtightening leading to skin problems. However, these disadvantages have been partially reduced by new interfaces like nasal pillows that have the capacity to reduce the contact of the silicone cushion with the skin, reducing the chances of skin irritation. At the same time, assuring a better seal prevents air leakage and is particularly useful in patients with internal valve insufficiency. We present a case of a 57-year-old patient with severe sleep apnea syndrome whose efficient treatment was delayed by an inadequate PAP mask prescription at diagnosis. Due to low treatment compliance secondary to the perceived adverse effects of the oronasal mask, the patient decided to discontinue treatment for two years with subsequent aggravation of sleep apnea symptoms. The patient’s sensitivity to the silicone mask cushion and treatment ineffectiveness due to internal valve collapse were the main causes of treatment failure. After changing of PAP interface, the patient achieved long-term compliance. Our case report reflects the importance of choosing the most suitable PAP interface in accordance with the patient’s particularities. In the absence of this approach, appropriate treatment might be delayed with detrimental consequences, especially in severe cases. Considering PAP adherence following therapy initiation usually predicts long-term compliance, finding the best mask design from the beginning can predict therapeutic success.

Issue Information

Scanning electron micrographs of two members of the marine diatom genus Nagumoea, N. africana (the left four photos) and N. serrata (the right two). This genus is characterized as unique by the ladder‐like structure of its internal valve as shown in the image. Morphology and molecular phylogeny of this genus are reported by Sugawara et al. in this issue.image

Video-Assisted Septo-rhinoplasty, the Future of Endonasal Rhinoplasty-A Technical Note.

Surgeons have sought to improve outcomes in rhinoplasty through innovative techniques. Although many publications illustrate the advantages of endoscopic septoplasty over conventional methods, few have evaluated the benefits of endoscopy for rhinoplasty. In this article, the authors meticulously describe their own technique that offers a sustainable alternative to open approach rhinoplasty, with high reproducibility and enhanced knowledge for young surgeons. The technique involves using video-assisted endoscopy for enhanced visibility and access. Various steps are performed, including hemitransfixion incision, septoplasty if necessary, dorsal reduction, and the development of endoscopic spreader flaps. Nasal tip surgery follows standard endonasal rhinoplasty techniques. This technique has been successfully performed for years in primary and secondary rhinoplasties, resulting in improved aesthetic and functional outcomes without external scars. The endoscopic view enhances understanding for surgeons and residents, while preserving internal valve function and minimizing swelling. Patients express high satisfaction with the procedure. Video-assisted endoscopic septo-rhinoplasty offers a valuable alternative, providing natural outcomes with improved visualization and reduced complications. It is applicable to various indications and demonstrates its effectiveness compared to traditional approaches. The advanced endoscopic guided septo-rhinoplasty technique combines the benefits of open approach rhinoplasty while avoiding its drawbacks. This journal requires that authors assign a level of evidence to each submission to which Evidence-Based Medicine rankings are applicable. This excludes Review Articles, Book Reviews, and manuscripts that concern Basic Science, Animal Studies, Cadaver Studies, and Experimental Studies. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

#5863 A NOVEL SELF-SEALING DIALYSIS PORT EVALUATION

Abstract Background and Aims There are several complications associated with hemodialytic vascular that arise from the incorrect cannulation, including aneurysms, infection, vessel damage, and uncontrolled bleeding. These risks severely limit treatment opportunities for self-cannulation by patients, which is necessary step for home hemodialysis. To improve quality of life and reduce complications, we developed a novel access port, called Safe Entry Port for AV fistuLae (SEAL), that integrates with fistulae, guides cannulation, and uses an internal colinear valve to prevent aneurysms with minimal risk of back-bleeding and infections (Figure 1A-C). Method The device was additively manufactured using direct metal laser sintering of FDA-approved Ti-6Al-4V. It was then polished and coated with silver-doped titanium nitride (TiN/Ag). The operation of the valve was tested in a mock circulation system using a peristaltic pump and Tyvek tubing to produce a pulsatile hydrostatic pressure gradient. The antimicrobial properties of the valve coating were evaluated in vitro against biofilm formation using standard assays for bacterial spreading area and turbidity. A custom computer-controlled robotic cannulation system was created to fatigue test the port as well as to determine the needle force required to open the valve. Finally, the device was implanted subdermally on a mature brachiocephalic arteriovenous fistula of an adult sheep and cannulated biweekly for six weeks. Device integration and host tissue reaction were evaluated using standard histopathological methods and micro-CT scanning. Results SEAL is engineered to integrate directly over a fistula via a Ti matrix (a mesh of small holes covering the sides of the device for interaction with host tissue). No fluid leaked through the valve during in vitro testing even under physiologically high circulatory pressure. In repeated cannulations of the device during ex vivo simulations with 14G dialysis needles, the peak force required to engage the valve recorded in our dialysis fatigue cycling simulation was 160.5 $ \pm $ 0.02 mN (Figure 1D, E). The device withstood cannulation cycles equivalent to 14 years of dialysis. Furthermore, the colinear valve smoothly opened for continuous flow through the needle guide (Figure 1F-I) and closed automatically under the tensile force similar to that of subcutaneous tissue. Antimicrobial TiN/Ag coating showed significant reduction in bacterial growth in both biofilm assays (Figure 1J,K). In preclinical trials, no signs of infection or backbleeding were observed during the continuous six-week cannulation period; vascular access was continuous with no resistance or complications. Conclusion We show that SEAL nearly eliminates backbleeding risk both in vitro and in vivo. The TiN/Ag coating of the colinear valve significantly limits bacterial biofilm formation ex vivo. Preclinical studies in the sheep model show that the device implanted on a mature fistula can easily be cannulated twice a week without any infection, cannulation complications, or backbleeding for an extensive period. SEAL has the potential to change the future of dialysis treatments, improve the quality of life for patients due the reduction of complications, and allow improved access to home hemodialysis.

A comprehensive diagnosis method of valve leakage faults based on bi-sensor information fusion

Acoustic emission (AE) signals caused by valve leakage exhibit obvious nonlinearity and nonstationarity characteristics. Due to the limitations of traditional valve leakage diagnosis methods, it is difficult to distinguish between internal and external valve leakage failures effectively. Recognizing this challenge, a comprehensive valve leakage diagnosis method based on a multichannel fusion convolutional neural network (MCFCNN) is proposed. First, AE signals are converted from one-dimensional time-domain signals to two-dimensional time–frequency images by the time–frequency analysis method. Then, the time–frequency images are used as model inputs, and MCFCNN fuses the features of time–frequency images from two different position. Hence, a new comprehensive diagnosis method for the bi-sensor fusion contains the time–frequency information, modal information, and position information of valve leakage is proposed. Subsequently, the effectiveness of the proposed method was verified through valve leakage simulation experiments. Furthermore, in order to study the impact of modal information on identifying internal and external valve leakage faults, the fault prediction performance of MCFCNN was compared and analyzed using short-time Fourier transform (STFT) and time-reassigned synchrosqueezing transform (TSST). Finally, according to the needs of engineering practice, the impact of sampling length on different methods is studied. The results show that compared to STFT–MCFCNN, TSST–MCFCNN required a shorter sampling length with the same diagnostic accuracy, which means that the method proposed in this study can achieve faster response time for ball valve leakage under conventional leakage flow rates.

Optimization of design variables and control rules in field development under uncertainty: A case of intelligent wells and CO2 water alternating gas injection

This paper focuses on life-cycle optimization of oil field development plan under uncertainty. The optimization problem included a wide range of design variables and control rules related to wells and platform in a realistic benchmark case (UNISIM–II–D) with a known ground truth reservoir model, UNISIM–II–R, that resembles Brazilian pre-salt fractured carbonate reservoirs in their early development stage. The design variables were the number and location of wells, the fluid processing capacity of the platform, and the location of internal control valves (ICVs), whereas the control rules were the setting of ICVs, production and injection rates, and the duration of the water-alternating-gas (WAG-CO2) cycle. An iterative sequential optimization framework was developed to deal with the massive search space and complex parameterization. The optimization further took into consideration the subsurface, operational and economic uncertainties, and used iterative discrete Latin hypercube method as the search algorithm. The robust optimization was carried out on a subset of representative models derived from the reduction of a large ensemble of data-assimilated models. As a low-fidelity representation of the compositional fluid model, a black-oil model was used to reduce simulation runtime. To validate our optimization framework, we applied the optimal development strategy to the ensemble of compositional simulation models, as well as the ground truth model. The true model's responses were within the ranges predicted by the compositional ensemble, confirming the optimization framework's reliability. The general methodology developed in this study, as well as our findings, can be used to optimize other similar real-world complex and high-risk field development projects, and are especially useful in closed-loop field development and management practices.