KINEMATICS OF THE DISTRIBUTION MECHANISM OF THE HYUNDAI ENGINE WITH ADJUSTABLE VALVE OPERATING TIME

Increasing the efficiency of modern internal combustion engines is going in the direction of optimizing the gas distribution phases in order to adjust them to the operating conditions of motor vehicles. Hyundai has announced the development of the first production engine with continuously variable valve operation time – Continuously Variable Valve Duration. (Research purpose) The research purpose is in conducting a kinematic analysis of the gas distribution mechanism with an adjustable valve operating time, identifying the theoretical possibilities of this mechanism in comparison with the information provided in the prospects. (Materials and methods) The methods of kinematic analysis of lever mechanisms were used in the work. (Results and discussion) The analysis of the design of the gas distribution mechanism with an adjustable valve operating time made it possible to choose a suitable structural scheme that is equivalent to the original mechanism. The article presents the most effective method of kinematic analysis of this mechanism and developed on its basis a program for calculating the angles of rotation of the cam and the shaft of the gas distribution mechanism. (Conclusions) An engine with a valve operating time control system allows you to more effectively adjust the cylinder filling depending on the operating conditions due to the variable phase of rotation of the camshaft. The valve timing control system offered by Hyundai should only work with the valve timing control mechanism, since when the cam rotation speed changes, it starts working in the wrong phase that should be at a given time. With a slow rotation of the cam, it lags behind in phase from the shaft of the gas distribution mechanism, and with a fast rotation of the cam, on the contrary, the phase advance of the shaft of the gas distribution mechanism occurs.

Shunt performance in 349 patients with hydrocephalus after aneurysmal subarachnoid hemorrhage

Background Shunt-dependent hydrocephalus after aneurysmal subarachnoid hemorrhage (aSAH) is a common sequelae leading to poorer neurological outcomes and predisposing to various complications. Methods A total of 2191 consecutive patients with aSAH were acutely admitted to the Neurointensive Care at the Kuopio University Hospital between 1990 and 2018 from a defined population. A total of 349 (16%) aSAH patients received a ventriculoperitoneal shunt, 101 with an adjustable valve (2012–2018), 232 with a fixed pressure valve (1990–2011), and 16 a valveless shunt (2010–2013). Clinical timelines were reconstructed from the hospital records and nationwide registries until death (n = 120) or June 2019. Results Comparing the adjustable valves vs. the fixed pressure valves vs. the valveless shunts, intraventricular hemorrhage was present in 61%, 44% and 100%, respectively. The median times to the shunt were 7 days vs. 38 days vs. 10 days. The rates of the first revision were 25% vs. 32% vs. 69%. The causes included infection in 11% vs. 7% vs. 25% and overdrainage in 1% vs. 4% vs. 31%. The valveless shunt was the only independent risk factor (HR 2.9) for revision. After the first revision, more revisions were required in 48% vs. 52% vs. 45%. Conclusions The protocol to shunt evolved over time to favor earlier shunt. In post-aSAH hydrocephalus, adjustable valve shunts, without anti-siphon device, can be installed at an early phase after aSAH, in spite of intraventricular blood, with a modest risk (25%) of revision. Valveless shunts are not recommendable due to high risk of revisions.

Aqueductal CSF stroke volume measurements may drive management of shunted idiopathic normal pressure hydrocephalus patients

CSF shunting with adjustable valve is the treatment of idiopathic normal pressure hydrocephalus. The opening pressure valve setting is left to the neurosurgeon’s experience. Aqueductal CSF stroke volume by phase-contrast magnetic resonance measures the CSF passing through the Sylvian aqueduct and it changes with intracranial hydrodynamics. We sought to identify a window of stroke volume differences associated with the best clinical outcome and lowest rate of complications. The records of 69 patients were reviewed. At every clinical check, stroke volume, opening pressure valve, clinical outcome, and CSF overdrainage were analyzed. The correlation between stroke volume differences and negative outcome was also analyzed. The median follow-up was 2.3 years (range 0.3–10.4 years). The odds of negative outcome between two consecutive checks significantly increased by 16% (95%CI 4–28%, p = 0.006). Taking the lowest risk group as reference, the odds ratio of negative outcome was 1.16 (95%CI 0.51–2.63, p = 0.726) for SV differences less than − 37.6 µL, while it was 1.96 (95%CI 0.97–3.98, p = 0.062) for stroke volume changes above + 23.1 µL. Maintaining stroke volume values within a definite range might help maximize clinical benefit and avoid the risk of CSF overdrainage.

Drill rig with a down-the-hole hammer for regulating the drilling rate by changing the air flow

At present, a lack of efficiency of the rotary drilling intensification can be observed at mining enterprises that employ drill rigs. Due to this, we propose to enhance the rotary drilling using shock loads by installing a down-the-hole (DTH) hammer into the drill string of the rig for roller drilling, for instance, SBSh-250. The paper discusses the issue related to an increase in the drilling rate using a drill rig with DTH hammer and adjustable valve that regulates the air flow. The paper considers different types of drilling in engineering and geological surveys. Rocks were sampled for various types of drilling. The physical and mechanical properties of rocks, which affect the drilling process, were considered. The study focuses on a significant increase in the drilling rate through an increase in the impact power. As part of the study, an improved drill rig with a down-the-hole hammer controlled by a radio receiver was developed. When analyzing the physical and mechanical properties, it was shown that the control of DTH hammer operation enables fast drilling of complex rocks without reducing the drilling rate. An increase in the drilling rate of self-propelled equipment using DTH hammers installed above the drill bit will reduce the cost of drilling and extend the service life of the working tool.

Adjustable Valve Semi-Active Suspension System for Passenger Car

The suspension of the car plays a very important role in the safety and the comfort of the vehicle and for absorbing the shock waves and give comfort for the driver and passenger. This paper improves the performance of an automobile suspension system by developing electronically adjustable semi-active shock absorber. This achieved by attaching stepper motor for each shock absorber which helps in adjusting the bleed orifice to a certain position that alternates the hydraulic oil flow in the shock absorber between piston’s chamber during the process of compression and rebound. To evaluate the effect of developed semi-active shock absorber on the dynamic behaviour of the vehicle, several tests were carried out on different types of road condition (bumpy, straight-line and roundabout). These tests were used to evaluate the acceleration and ride quality. There is a great range in response when the bleed orifice is opened reached up to 35% between the stiff and soft setting. The value of root means square acceleration (RMS) was calculated and compared with the standard of human exposure to whole-body vibration, which shows an error of 6% slightly. The result shows the effect of electronically controllable shock absorber on a vehicle’s dynamic behaviour — the advantage of electronics to improve the performance of ride comfort and reduced the harms due to undesired vibration.

Optimization of Codman® Hakim® adjustable valve radiography

Purpose Cerebrospinal fluid shunt valves is an important tool in hydrocephalus treatment. Adjustable valves, sensitive to MRI, are onerous. They need be controlled; in case of re-settings. The vendor give advices for the radiographic procedure; however, hospitals use variations. The purpose was to investigate the different variations. Method Eight images consisting combinations of protocol features, were subjectively and anonymous rated for image quality. The panel consisted of 60 professionals; 50 radiographers and 10 radiologists, from two hospitals doing neurosurgery services. Signal-to-noise ratio compared the level of desired signal to the level of background noise. Results 348 scores were distributed onto all eight images, revealing the image quality difference was within acceptance. Options as valve on the head side near to the detector versus far to; differing geometry, use of head bowl versus not use, air-gap versus grids, were favored by both professional groups and at both hospitals in a clear priority image, given 2.5 times scores over average (108/43). Noise, revealed being the strongest indicator for priority of the best image for shunt evaluation. ConclusionsIt is a potential to improve image optimization in shunt radiography.

A randomized controlled dual-center trial on shunt complications in idiopathic normal-pressure hydrocephalus treated with gradually reduced or “fixed” pressure valve settings

Object This study was undertaken to investigate whether a gradual reduction of the valve setting (opening pressure) decreases the complication rate in patients with idiopathic normal-pressure hydrocephalus (iNPH) treated with a ventriculoperitoneal (VP) shunt. Methods In this prospective double-blinded, randomized, controlled, dual-center study, a VP shunt with an adjustable valve was implanted in 68 patients with iNPH, randomized into two groups. In one group (the 20–4 group) the valve setting was initially set to 20 cm H2O and gradually reduced to 4 cm H2O over the course of the 6-month study period. In the other group (the 12 group), the valve was kept at a medium pressure setting of 12 cm H2O during the whole study period. The time to and type of complications (hematoma, infection, and mechanical problems) as well as overdrainage symptoms were recorded. Symptoms, signs, and outcome were assessed by means of the iNPH scale and the NPH grading scale. Results Six patients in the 20–4 group (22%) and 7 patients in the 12 group (23%) experienced a shunt complication; 9 had subdural hematomas, 3 mechanical obstructions, and 1 infection (no significant difference between groups). The frequency of overdrainage symptoms was significantly higher for a valve setting ≤ 12 cm H2O compared with a setting > 12 cm H2O. The 20–4 group had a higher improvement rate (88%) than the 12 group (62%) (p = 0.032). There was no significant relationship between complications and body mass index, the use of an antisiphon device, or the use of anticoagulants. Conclusions Gradual lowering of the valve setting to a mean of 7 cm H2O led to the same rate of shunt complications and overdrainage symptoms as a fixed valve setting at a mean of 13 cm H2O but was associated with a significantly better outcome.

Hydrodynamic properties of the Certas hydrocephalus shunt

Object Independent testing of hydrocephalus shunts provides information about the quality of CSF drainage after shunt implantation. Moreover, hydrodynamic parameters of a valve assessed in the laboratory create a comparative pattern for testing of shunt performance in vivo. This study sought to assess the hydrodynamic parameters of the Certas valve, a new model of a hydrocephalus shunt. Methods The Certas valve is an adjustable ball-on-spring hydrocephalus valve. It can be adjusted magnetically in vivo in 7 steps, equally distributed within the therapeutic limit for hydrocephalus, and the eighth step at high pressures intended to block CSF drainage. The magnetically adjustable rotor is designed to prevent accidental readjustment of the valve in a magnetic field, including clinical MRI. Results The pressure-flow performance curves, as well as the operating, opening, and closing pressures, were stable, fell within the specified limits, and changed according to the adjusted performance levels. The valve at settings 1–7 demonstrated low hydrodynamic resistance of 1.4 mm Hg/ml/min, increasing to 5.1 mm Hg/ml/min after connection of a distal drain provided by the manufacturer. At performance Level 8 the hydrodynamic resistance was greater than 20 mm Hg/ml/min. External programming of the valve proved to be easy and reliable. The valve is safe in 3-T MRI and the performance level of the valve is unlikely to be changed. However, with the valve implanted, distortion of the image is substantial. Integration of the valve with the SiphonGuard limits the drainage rate. Conclusions In the laboratory the Certas valve appears to be a reliable differential-pressure adjustable valve. Laboratory evaluation should be supplemented by results of a clinical audit in the future.

Failure Mode Recognition Clustering Algorithm Based on Manifold Learning

Manifold learning is a new unsupervised learning method. Its main purpose is to find the inherent law of generated data sets. Be used for high dimensional nonlinear fault samples for learning, in order to identify embedded in high dimensional data space in the low dimensional manifold, can be effective data found the essential characteristics of fault identification. In many types of fault, sometimes often failure and normal operation of the equipment of some operation similar to misjudgment, such as oil pipeline transportation process, pipeline regulating pump, adjustable valve, pump switch, normal operation and pipeline leakage fault condition similar spectral characteristics, thus easy for pipeline leakage cause mistakes. This paper uses the manifold learning algorithm for fault pattern clustering recognition, and through experiments on the algorithm is evaluated.