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The selective transport of ions in nanopores attracts broad interest due to their potential applications in chemical separation, ion filtration, seawater desalination, and energy conversion. The ion selectivity based on the ion dehydration and steric hindrance is still limited by the very similar diameter between different hydrated ions. The selectivity can only separate specific ion species, lacking a general separation effect. Herein, we report the highly ionic selective transport in charged nanopore through the combination of hydraulic pressure and electric field. Based on the coupled Poisson–Nernst–Planck (PNP) and Navier–Stokes (NS) equations, the calculation results suggest that the coupling of hydraulic pressure and electric field can significantly enhance the ion selectivity compared to the results under the single driven force of hydraulic pressure or electric field. Different from the material-property-based ion selective transport, this method endows the general separation effect between different kinds of ions. Through the appropriate combination of hydraulic pressure and electric field, an extremely high selectivity ratio can be achieved. Further in-depth analysis reveals the influence of nanopore diameter, surface charge density and ionic strength on the selectivity ratio. These findings provide a potential route for high-performance ionic selective transport and separation in nanofluidic systems.

The fouling behavior of osmotically-driven forward osmosis (FO) is widely believed to be superior with respect to hydraulic pressure-driven membrane applications, based on a number of experiments reported in the literature. However, experimental confounders often exist, preventing fair comparison between the different processes, one being the deployment of non-comparable membranes. This study systematically investigates the conditions influencing organic fouling in FO and compares the behavior in FO and in a hydraulic pressure-driven process, under equivalent conditions. The same state-of-the-art polyamide FO membranes were used in the tests, which were run with real feed solutions and under varying conditions to observe the effect of initial flux, draw solution, and feed ionic composition. The results suggest that initial flux and calcium have the strongest influence on the extent of flux decline and recovery. The influence of different draw solutions in FO becomes apparent when the flux is relatively low. Analysis of the fouling indices and of the effective driving force, as well as direct observation of membranes following fouling, support the conclusion that the fouling behavior of the FO process is not necessarily better compared to an analogous hydraulic pressure-driven one, especially under relevant operational conditions and when the two processes work with similar fluxes.

We have evaluated a long-term drift of hydraulic pressure gauges which are kept under constant pressure application. Three pressure gauges were pressurized and kept at 100 MPa, and the variations in calibration results at 100 MPa have been traced for 800 days. The calibration results significantly varied immediately after the pressure application, and the variation rate became small and almost constant as the pressure was continuously applied. The observed drift trend was different from the drift which is observed when the gauges are always kept at atmospheric pressure. In addition, during the pressure application, the pressure was intermittently released to atmospheric pressure for a short time, and outputs at atmospheric pressure were obtained. The calibration results at 100 MPa and atmospheric pressure showed a similar drift trend, showing that most part of the drift under pressure can be corrected by zero offset. Several methods are proposed to appropriately evaluate and correct the long-term drift of pressure gauges during use under constant pressure application.

The failure models developed until the 1960ies were defined by the testing equipment: the triaxial loading cell which was developed at the beginning of the last century by Karman. The axial loading was performed with a solid loading plate, the central-symmetric transverse loading through hydraulic pressure. Therefore, the characterization of the failure surface with the hydrostatic normal stress and octahedral shear stress without any reference to deformations was a logical consequence. In 1963 Hilsdorf proposed a brush-type loading equipment. Using brushes Kupfer carried out his wellknown biaxial loading tests which made possible the characterization of concrete strength by means of the principal stresses. In 1977 Ottosen applied in his model for multiaxial strength of concrete the stress invariants. The same did CEB in the Bulletin d’Information N°. 156. Van Mier (1984) applied brushes and proposed a 3D-type representation using contour lines. The MC2010 returned to the Ottosen model and declared concrete as frictional material. Using the principal stresses, a new, transparent (and physically really sound) form of representation of the failure surface showing the strength increase due to bi- and triaxial loading is presented.

Although the apply of hydrostatic guideways in high precision machine tools is desirable, fewer companies are involved in marketing this type of guideway due to the high precision manufacturing required to produce the hydrostatic guideways and the complexity of the hydraulic system. In order to improve the accuracy of a portal-type milling machine to be designed as part of a departmental project, special guideway designs have been investigated, resulting in a slideway structure relieved with hydraulic pressure chambers. A measuring bench was set up to check the amount of relief. Based on the primary measurements performed, the structure relieves the load by providing a suitable sliding surface.

We demonstrate a silica diaphragm-based fiber tip Fabry&ndash, Perot interferometer (FPI) for high-pressure (40 MPa) sensing. By using a fiber tip polishing technique, the thickness of the silica diaphragm could be precisely controlled and the pressure sensitivity of the fabricated FPI sensor was enhanced significantly by reducing the diaphragm thickness, however, the relationship between the pressure sensitivity and diaphragm thickness is not linear. A high sensitivity of &minus, 1.436 nm/MPa and a linearity of 0.99124 in hydraulic pressure range of 0 to 40 MPa were demonstrated for a sensor with a diaphragm thickness of 4.63 &mu, m. The achieved sensitivity was about one order of magnitude higher than the previous results reported on similar fiber tip FPI sensors in the same pressure measurement range. Sensors with a thinner silica diaphragm (i.e., 4.01 and 2.09 &mu, m) rendered further increased hydraulic pressure sensitivity, but yield a significant nonlinear response. Two geometric models and a finite element method (FEM) were carried out to explain the nonlinear response. The simulation results indicated the formation of cambered internal silica surface during the arc discharge process in the fiber tip FPI sensor fabrication.

By simultaneous expansion of the ends of two connected pipes in the same tool and subsequent welding in the deformed state, it is possible to prevent the formation of steps that increase the hydraulic pressure, with corresponding gains in pipeline quality.

Estimation of the oil hydraulic pressure for the gear-shift elements can be useful for the development of closed-loop control of the automatic transmission fitted to a heavy off-highway vehicle for a good gear-shift quality, to reduce the dissipated energy and the vehicular shift jerk in complex working conditions. The unified dynamic model for a three-degree-of-freedom planetary automatic transmission is presented, and the power-on upshift from first gear to second gear is considered as an example. The unified model is more efficient than the conventional model for the dynamic analysis; furthermore, it provides a computational method for the inertia of the transmission when in gear. From a phased characteristic analysis, real-time estimation of the oil pressure for the gear-shift elements in the sliding process, i.e. the torque phase and the inertia phase, is addressed; then the improved control scheme for the power-on upshift from first gear to second gear is developed and validated using a heavy off-highway vehicle equipped with a high-power full-range speed-regulating diesel engine. The experimental results show that the model-based oil pressure estimation is able to reflect the dynamic characteristics of the system in changing conditions, and the corresponding control strategy can improve the gear-shift quality and the vehicular performance effectively.

Asymmetric track-etched membranes based on polyethylene terephthalate have been prepared using two-sided irradiation on the heavy-ion accelerator DC-60. A process for cyclotron adjustment to bombardment of a polymer material has been described. A procedure for preparing asymmetric track-etched membranes with different pore lengths and sizes has been specified. The strength characteristics of the resulting membrane have been evaluated. It has been shown that the membrane can be used in processes in which the driving force is hydraulic or osmotic pressure.

We developed a high gas pressure calibration system that uses a liquid-lubricated (LL) pressure balance as a standard for pressures up to 100 MPa. The LL pressure balance can generate gas or hydraulic pressure by changing the pressure medium. We first evaluate characteristics of the LL piston–cylinder (PC), such as its effective area and fall rate. The effective area of the LL PC is evaluated through comparison with a hydraulic pressure balance. When the LL PC uses a gas, the fall rate is affected by gas dissolution into liquid in the LL PC reservoir. The results of calibrating a pressure gauge under the developed system are consistent with those by an existing hydraulic pressure calibration system.

When the heating pipelines have a large height difference on the way of laying, which is lead to increase the resistance of heating network and make hydraulic regime complicated. This paper presents a feasibility study of the long-distance heating pipeline project from Yangcheng Power Plant in Shanxi Province to Jincheng city which is carried out through the comparative analysis of the hydraulic pressure diagram. According to the optimal route, the following four schemes are proposed: (1) First-stage pressurization of the first station. (2) Multi-stage pressurization of relay-pump station. (3) Setting up intervals-pressure heat exchange station. (4) Combination of relay-pump station and intervals-pressure heat exchange station. The advantages and disadvantages of them are analyzed, respectively. As a result, only Scheme 4 meets the requirements of hydraulic conditions and the optimal location of the relay-pump station is determined be 9550 m away from the first station. This paper is intended to contribute a solution to the long-distance central heating with large height difference.

Because of the large rotating inertia of large radar antenna, the time-delay effect is obvious. When precise positioning control is carried out, the sampling period is required to be short, and the adverse effect of time-delay effect is obvious. How to reduce the influence of transmission chain error on positioning control accuracy is particularly important. In this paper, a locking strategy for low-speed axle brake is proposed. The advantages and disadvantages of common brakes and the installation methods of different locations are compared. The composition and characteristics of hydraulic disc brake are introduced in detail. The precise positioning process and application effect of hydraulic disc brake applied to a large radar antenna are emphatically discussed. The test results show that the positioning accuracy and repetitive positioning accuracy of the system are higher than 0.01 degrees. The hydraulic disc brake is a new type of brake and it combines the hydraulic pressure with the control. The engineering experience has proved that the safety of the hydraulic disc brake is high. It is especially suitable for the safe braking and precise positioning of large radar antenna.

It is the intention of the authors to let the students understand the underlying principles of membrane separation processes by solving the problems numerically, in general. In particular, in this article problems and answers are presented for reverse osmosis (RO), one of the membrane separation processes driven by the transmembrane hydraulic pressure difference. The transport theories for RO were developed in early nineteen sixties, when the industrial membrane separation processes emerged. These problems are solved step by step using a simple calculator or Excel in computer.

Nanoimprint lithography (NIL) is the next-generation alternative to conventional photolithography involving an inexpensive and high throughput process. However, conventional NIL equipment requires a bulky air compressor which possesses a large area. This study aims to overcome this limitation by introducing a novel hydraulic ultra-violet (UV) imprint system. Hydraulic UV imprint system can be used to conduct the UV NIL process by using a simple, low-cost materials without needing complex equipment. To form various patterned layers, UV NIL was conducted with various master stamps.(diameter: micro-cones:3 μm, nanopillars:200 nm, nanoholes: 200 nm) The performance of the imprint system was verified by using scanning electron microscopy analysis of samples fabricated by new system. The results showed that the performance of the new imprint system was comparable to that of a conventional air-pressure UV imprint system.

Combined with the technical characteristics of hydraulic pressure test and acoustic emission technology in nuclear power station, this paper discusses the application status and technical features of acoustic emission technology in primary circuit hydraulic pressure test, vessel hydraulic pressure test, boundary valve leak detection of hydraulic pressure test and pipeline hydraulic pressure test in detail, and this paper also looks forward to the application prospect of acoustic emission technology in the field of hydraulic pressure test in nuclear power station.

Direct contact membrane distillation (DCMD) is a membrane distillation (MD) configuration where feed and distillate directly contact with a hydrophobic membrane. Depending on its operating conditions, the hydraulic pressures of the feed and distillate may be different, leading to adverse effects on the performance of the DCMD process. Nevertheless, little information is available on how hydraulic pressure affects the efficiency of DCMD. Accordingly, this paper investigates the effect of external hydraulic pressure on the process efficiency of DCMD. Gas permeabilities of MD membranes were measured to analyze the effect of membrane compaction by external pressure. Mass transfer coefficients were calculated using experimental data to quantitatively explain the pressure effect. Experiments were also carried out using a laboratory-scale DCMD set-up. After applying the pressure, the cross-sections and surfaces of the membranes were examined using a scanning electron microscope (SEM). Results showed that the membrane structural parameters such as porosity and thickness were changed under relatively high pressure conditions (&gt, 30 kPa), leading to reduction in flux. The mass transfer coefficients were also significantly influenced by the hydraulic pressure. Moreover, local wetting of the membranes were observed even below the liquid entry pressure (LEP), which decreased the rejection of salts. These results suggest that the control of hydraulic pressure is important for efficient operation of DCMD process.

A hydraulic experimental platform for the assembly of stator components was developed, and the simulation on this system was performed based on software AMEsim. Characteristics of the system, such as the pressure and the displacement, were analyzed. The results guide design of the hydraulic system of experiment platform for the assembly of the stator.

Nappe behavior should be considered in the design of labyrinth weirs to ensure hydraulic optimization and to account for potential vibrations, pressure fluctuations, noise, and flow surging. Information regarding nappe aeration conditions (clinging, aerated, partially aerated, and drowned), nappe instability, and nappe vibrations for trapezoidal labyrinth weirs on a horizontal apron with quarter- and half-round crests (6°≤ sidewall angle ≤35°) is presented. Corresponding headwater ratio ranges and hydraulic behaviors associated with nappe aeration conditions are documented and discussed to aid in labyrinth weirs design, including design options directly related to nappe behavior (e.g., crest shape, crest roughness, vents, nappe breakers, notches, and staged cycles). The effects of artificial nappe aeration (a vented nappe) on nappe behavior and discharge capacity are also discussed, including recommended placements of nappe breakers.

Background We previously showed that application of hydraulic pressure to cultured human keratinocytes induced elevation of intracellular calcium concentration ([Ca2+]i), but the absolute value of the pressure could not be determined. Purpose To evaluate the effect of the absolute value of pressure on keratinocytes and other skin cells. Methods In the present work, we examined the effect of changes in absolute pressure level by observing the [Ca2+]i responses of cultured human keratinocytes and other cells cultured at the bottom of a hermetically sealed plastic flask as the air pressure in the flask was increased gradually, held stable, and then decreased abruptly, using the Ca2+-indicator fura-2. Results We found that the [Ca2+]i of differentiated keratinocytes was changed significantly in each phase, whereas undifferentiated keratinocytes and other cells derived from skin or dorsal root ganglion showed no response. Removal of calcium from the medium blocked the increase in [Ca2+]i in differentiated keratinocytes. The [Ca2+]i responses of individual differentiated keratinocytes in the increasing, stable and decreasing phases of pressure change varied from cell to cell. The threshold of air-pressure increase from the original level for inducing [Ca2+]i response was 5 – 20 hPa. Conclusion These results suggest that epidermal keratinocytes might contain a sensory system that detects changes of external pressure on the skin.

A new process called fine hydromechanical blanking is proposed in this paper. In contrast to conventional fine blanking, in fine hydromechanical blanking, the V-ring indenter on the guide plate is replaced by a V-ring cavity formed in a workpiece and pressurized by hydraulic pressure. In addition, the counterforce from the blanking ejector is replaced by the hydraulic pressure acting on the ejector chamber. An experimental algorithm for optimization based on the Taguchi method, in which a genetic algorithm is used for searching, is proposed to determine the largest shear-zone length. From the experimental results, it is concluded that the proposed method can achieve the same effects as conventional fine blanking. In addition, an investigation of the effect of the hydraulic pressure in the V-ring cavity and ejector chamber on the shear-zone length was conducted through a series of experiments. The results show that the experiments were greatly affected by the height of the burnished surface and indicate the significance of the hydraulic pressure in the V-ring cavity and ejector chamber.

IEEE VPPC 2016, the 13th Vehicle Power and Propulsion Conference, Hangzhou, CHINE, 17-/10/2016 - 20/10/2016; Most of the commercial river ships dedicated to load transport are propelled by a conventional power train architecture. Two mains engines are connected to two propellers, and one or more electrical generators provide the on-board power (electricity, hydraulic pressure ...) to the servitudes. In a lot of operations, the main engines and the auxiliary engines are not employed to their maximum abilities and operate on bad efficiency areas. Hybrid solutions with batteries can then improve the operations of the engines allowing to shut them off, or to operate them in better efficiency area. This paper evaluates the potential of hybrid solutions dedicated to Inland Waterways Transport regarding the potential of fuel economy. Measurements have been performed to model the components of the ship and its operations (uses cycle). Then different hybrid architectures have been modeled, sized and compared to the conventional power-train.

Seals are used in hydraulic actuators or any other hydraulic devices to prevent passing of hydraulic fluid from one chamber to another, or to prevent external leakage and entry of any foreign contaminants. The primary function of any hydraulic actuator is to efficiently use hydraulic power to drive a load experienced during movement of control surfaces or movable aircraft structure. Efficient sealing helps in achieving this, but with its own friction which should be as minimal as possible. Thus, the estimation of seal friction force has crucial significance in hydraulic actuators, especially in flight control actuators that demand high performance and dynamic behavior characteristics while efficiently driving the load. This paper details the methodology adopted for theoretical estimation of total seal friction force of actuator as well as description of experimental test set-up and test method followed to record the total friction value at different positions of the actuator. The theoretical estimation was done using empirical formulae and graphs for predicting seal friction force by considering the effects of seal squeeze, hydraulic pressure, seal dimensions, seal material and then interpolating the same for the specific type of seals used. An experimental study is also presented in this paper, which can be conducted to validate the theoretically estimated value after building up of development prototypes. The validation is necessary as seal friction force calculation during design phase is an approximation and accurate friction of every seal is difficult to measure as it depends on a number of parameters. Thus, this paper explains the subject issue with the help of a case study which provides the theoretical estimation as well as its validation through an experiment to study this significant aspect of a hydraulic actuator design.

Os manômetros são indispensáveis para a calibração de pulverizadores para atender à necessidade de pressão conforme o modelo de ponta de pulverização, volume de calda e defensivo agrícola. O objetivo desse trabalho foi realizar a avaliação destes equipamentos, sendo considerados cinco variáveis : estado de funcionamento; diâmetro externo; aferição da precisão; nível de glicerina no manômetro e tempo de uso do pulverizador. Foram inspecionados 36 pulverizadores por meio de visitas aleatórias a propriedades agrícolas. Os resultados mostraram tempo de uso médio dos pulverizadores em 16 anos, 8% estavam sem manômetros e mais de 30% com manômetros danificados. Entre os manômetros em funcionamento (61,1%), 31% apresentaram pressão atendendo ao erro tolerável (± 10%). Assim, dos 36 pulverizadores, apenas sete (19,4%) estavam com manômetros adequados.

Fatal injuries and deaths have occurred resulting from the operation or disassembling of a powder extinguishers in Korea. If a rusted powder extinguisher is exploded during operation or disassembling, it rises to the air like a rocket and hits a head, chest, or neck part of an operator, resulting in his (her) death or injury. In this study examines the explosion accident cases of a powder fire extinguisher and analyzes their causes, reactions to explosion, and precautionary measures. And in this paper suggests 1) no using of old fire extinguishers in fire drill or education, 2) education and public information on danger of old fire extinguishers, 3) indication of explosion danger to cartridge-type dry chemical powder fire extinguishers had already placed to buildings etc., 4) obligatory indication of durable years on fire extinguishers, 5) examination for introduction of system that do hydraulic pressure test about fire extinguishers that given period past, 6) construction of system that reclaim old fire extinguishers, 7) construction of system that recycle or reuse old fire extinguishers, and 8) operation of help desk related to old fire extinguishers as precautionary measure of fire extinguisher explosion accidents.

New hydraulic bulge method and estimated conjoint results were explored. The equipment’s overall water pressure test is developed to get lining bulge and plastic deformation, to eliminate the gap between lining and shell. Integrated effect was estimated by measured layer gap, stress and strain through hydraulic bulge and pressure increase test. Test results show that: although the preliminary gap is not uniform, even 14~16 mm at some points, but the remnant is only 0.6~0.9mm after hydraulic bulge; cylinder always keeps elastic during the pressure increase test, and the linearity between cylinder strain and initial pressure is more than 0.99 after hydraulic pressure expanding treated; Lower temperature annealing of sheath did not have negatively affect on conjoint effect. It is a new technology with simplicity, safety, low production cost, and no pollution, which will create a new way of metal compound forming.

A new controlled-clearance pressure balance has been developed to improve the hydraulic pressure standard for pressures up to 1 GPa. For several controlled-clearance (CC) piston-cylinders, characterization experiments based on the Heydemann–Welch (H–W) model were performed to estimate the pressure dependence of the effective area. The results of the experiments, specifically, the changes in the piston fall-rate and the generated pressure in response to the applied jacket pressure, are summarized for CC piston-cylinders of different pressure ranges. At pressures higher than a few hundred MPa, the characteristics of some piston-cylinders differed from those predicted by the H–W model. In this paper, a method for altering the deformational characteristics of CC piston-cylinders is examined. It was found that adjusting the area of the outer surface of the cylinder to which the jacket pressure is applied is an effective method for obtaining deformational characteristics that satisfy the conditions of the H–W model.

This study concerns a new rotary type water hydraulic pressure intensifier. The object of this paper is to introduce the structure and the working principle of the pressure intensifier, and to present the fundamental characteristics by experimental results. The basic structure is similar to that of a water hydraulic planetary gear motor. Its main part consists of a stator, a rotor, nine planetary gears and two side plates. The inside of the stator is formed by a curve with 5 lobes and the outside of the rotor is formed by a curve with 4 lobes. Their curved surfaces have teeth like a gear. Nine displacement chambers are formed by the stator, rotor, planetary gears and side plates, and the each chamber's volume varies periodically when the rotor rotates. A side plate has 5 inlet distribute holes and 5 outlet distribute holes alternately located on its surface. Each displacement chamber connects to an inlet distribute hole during the volume is increasing, and it connects to an outlet distribute hole during the volume is decreasing. Now, one of the outlet distribute holes is separated from the other 4, the intensified higher pressure water is discharged from the separated distribute hole. It is found that the critical intensification ratio is about 2.5 by experimental results with a prototype.

A new type of passive-pressurized hydromechanical deep-drawing (PHDD) tooling with two pistons is designed and manufactured: one piston installed inside is used to enhance the die pressure, the other is used to promote the radial-pushing pressure, which provides the radial-pushing and blank-holder forces. The advantage of the PHDD tooling is that it needs no external pressurizing source. Aimed at motions of the two pistons, a mathematical model is presented to calculate the hydraulic pressures of all chambers. Furthermore, relationships between those hydraulic-pressure zones are developed. Hydraulic deep-drawing experiment on 1.00-mm-thick 08Al steel was conducted, and a drawing ratio of 2.63 was obtained. Further analysis shows that the design of the new tooling is reasonable and the hydraulic pressure used in all experiments is in good agreement with the analytical results.

Usually, development of automobile brake hose and power steering hose has been realized through evaluating several actual prototype hoses experimentally. Recently, high durability and high development effect for brake hose has been required because periodic exchange for the brake hose has not been requested any more. In this study, therefore, stress analysis by FEM is performed to the crimped portion of hydraulic pressure brake hose in order to promote the development of the automobile hoses more efficiently. It is found that large normal stresses σr in the radial direction appear at the crimped portion between the nipple and inner rubber. The results suggest that several grooves on the nipple surface may be useful because they cause large σr, which may improve the sealing performance. The effect of permanent deformation of the rubber on the sealing performance is discussed by assuming initial deformation of the rubber at the crimped portion.

We developed a novel bending sensor for orientation control of hydraulic pressure driven active catheter. At beginning, we proposed and fabricated the bending sensor which was able to be included in the active catheter that was 3.0mm diameter. Some holes fabricated on the surface of a multimode optical fiber diffused light the inside of the fiber depending on curvatures. Measuring amount of light through the bending sensor indicated the bending angle was verified. In addition, we succeeded hydraulic pressure driven active catheter with the bending sensor and measured real time bending angle during control. This simple bending sensor satisfies for many fields such as medical devices and remote sensing because of its safety, microsize and simplicity.

Pressure fluctuations propagation within lining slab joints is one of the main causes of linings damage in stilling basins downstream of large dams. Based on three hydraulic models for pressure fluctuations propagation within lining slab joints proposed in the last 30 years, this paper uses both theoretical analysis and numerical simulation to study the mechanism of pressure propagation within joints. The result shows that these models have the inherent relationship but are adoptable to flows at different stages. The model of vibrating flow may simulate the flows within joints of lining slabs which vibrate randomly within their matrix. When lining slabs do not vibrate in their matrix, the model of transient flow can explain reasonably the mechanism of pressure fluctuations propagation within lining slab joints and the cause of fluctuating uplift generation. The model of seepage is only accepted when the joints of lining slabs are blocked completely.

To improve preferentially the permeability of fractures in the deepest parts of a geothermal reservoir, a dense fluid may be injected during the very first phase of a hydraulic stimulation test. To initiate such a permeability-enhancement process in the 5000 m deep reservoir of the European Enhanced Geothermal System (EGS) project at Soultz-sous-Forets, France, a concentrated NaCl brine was injected. The effects of this injection were estimated using measured hydraulic and microseismic data. Two tasks associated with hydraulic stimulation have been shown to be important for this purpose: (1) determination of the failure pressures of the various fractures intersecting the open-hole section under stimulation, and (2) calculation of the transient hydraulic pressure profile in the borehole. Using the numerical borehole code HEX-B, the transient pressure profiles during stimulation of wells GPK2 (June 2000) and GPK3 (May 2003) were calculated on the basis of measured wellhead data. A comparison of the temporal history of near-borehole microseismic events during the GPK2 test and downhole pressure development in the open-hole sections of this borehole indicated that use of a dense brine helped stimulate the bottom part of this well. The corresponding analysis for the GPK3 test showed that the failure pressure of the fractures in the bottom part of the wellbore was never exceeded when injecting the dense brine. We can, therefore, assume that the brine had no effect on the fractures in GPK3.

The active utilization of the pressure rise phenomenon of an oil hammer and a new type of hydraulic pressure intensifier using an oil hammer are proposed. In this paper, application of this intensifier to the hydraulic motor is studied through experimentation and simulation. The influence of the volume at the hydraulic motor entrance on the rotation angle and the pressure change is tested. The rotation angle of the hydraulic motor is made to follow up the desired value using a technique similar to that of PWM control. The relation between the rotation angle of the hydraulic motor and the pulse width for opening and shutting the solenoid-operated valve to generate an oil hammer is measured. Using the result, the rotation angle of the hydraulic motor is controlled to follow up the desired value. The influence of the load torque on te follow-up control and the efficiency is examined.

A piston-cylinder assembly from the Ulusal Metroloji Enstitusu (TUBITAK-UME, Turkey) was calibrated at the Laboratoire National d'Essais (BNM-LNE, France) and the Physikalisch-Technische Bundesanstalt (PTB, Germany) between March and December 1998 in the hydraulic gauge pressure range from 50 MPa to 500 MPa, using diethylhexyl sebacate as the pressure medium. Both institutes calibrated the assembly of the free-deformation type (manufacturer Desgranges et Huot, France; nominal effective area 2 mm(2)), from pressure balance comparison (cross-float) experiments with their primary standards and applied the "p method" to evaluate the calibration data. The consistency of all available calibration data was considered with respect to the realization of traceability in the 0.5 GPa range of hydraulic pressure by this method. New values of the effective area and the pressure distortion coefficient of the UME piston-cylinder assembly were derived from the results of this comparison. The present study also establishes a link to the latest EUROMET international comparison in the pressure range 50 MPa to 500 MPa.

Scaling up of microbial fuel cells (MFCs) without losing power density requires a thorough understanding of the effect of hydraulic pressure on MFC performance. In this work, the performance of an activated carbon air-cathode MFC was evaluated under different hydraulic pressures. The MFC under 100 mmH2O hydraulic pressure produced a maximum power density of 1260 ± 24 mW m(-2), while the power density decreased by 24.4% and 44.7% as the hydraulic pressure increased to 500 mmH2O and 2000 mmH2O, respectively. Notably, the performance of both the anode and the cathode had decreased under high hydraulic pressures. Electrochemical impedance spectroscopy tests of the cathode indicated that both charge transfer resistance and diffusion transfer resistance increased with the increase in hydraulic pressure. Denaturing gradient gel electrophoresis of PCR-amplified partial 16S rRNA genes demonstrated that the similarity among anodic biofilm communities under different hydraulic pressures was ≥ 90%, and the communities of all MFCs were dominated by Geobacter sp. These results suggested that the reduction in power output of the single chamber air-cathode MFC under high hydraulic pressures can be attributed to water flooding of the cathode and suppression the metabolism of anodic exoelectrogenic bacteria.

This paper presents the development of a microfluidic device consisting of an array of geometrically identical micromechanical stimulators that can simultaneously deliver differing magnitudes of mechanical strain for multiplex mechanical loading. Notably, all the micromechanical stimulators are driven by the hydraulic pressure from a single pumping unit, which greatly reduces the number of external pumps that are often needed in investigating magnitude-dependent mechanical loading. It thus provides a strategy for developing multiplex and high throughput microfluidic devices that involve magnitude-dependent operation.

We propose a simple design method of a ceramic pressure-tight housing having an extended length of cylinder and metal caps. Ceramics have higher compressive strength and lower specific gravity than typical metals. Moreover, they are free from erosion by seawater. For that reason, we can produce light pressure-tight ceramic housings that have good durability for deep-water applications. The proposed ceramic housings have greater buoyancy than metal housings. We also propose a simpler design method of metal caps. We confirmed its validity through Finite Element Method (FEM) analysis and hydraulic pressure tests using small-sized ceramic housings with metal caps.

Human periodontal ligament fibroblasts in culture were exposed to the controlled change in hydraulic pressure and were monitored continuously with an electric pressure gauge, and the concentration of intracellular calcium was measured in real time by a calcium-binding fluorescent dye, fluo-3. The elevation of hydraulic pressure to a level ranging from 20 to 50 mm Hg induced transient elevation of the intracellular calcium concentration in about 10% of the fibroblasts observed, indicating that these cells could respond to the pressure change. The results supported further an idea that periodontal ligament fibroblasts, responding to the pressure exerted by orthodontic force, would initiate the chain of events in orthodontic tooth movement, including alveolar bone remodeling. The threshold level of pressure (27 to 68 g/cm 2 ) obtained in this experiment, at which the fibroblasts started to respond, would provide a biochemical basis to determine the optimal magnitude of stress for clinical orthodontics. (A M J O RTHOD D ENTOFAC O RTHOP 1996;109:244-8.)

Strength tests have been carried out on 280 mm diameter discs of float glass loaded by hydraulic pressure against a 254 mm diameter anvil. This arrangement gives nearly equibiaxial loading over a large part of the plate. Failure stress and position of failure have been determined for a large number of bottom (tin) surface samples subjected to a standard handling procedure. Stresses have been calculated at the points of failure using the large deflection theory. By considering different concentric areas of the discs, and treating failures outside these regions as statistical suspensions, strength distributions have been determined for different stressed areas of the discs. This procedure overcomes the problem experienced by many workers in obtaining consistent samples for tests with different loading geometries. The distributions for the different stressed areas have an essentially constant Weibull modulus and a median stress that increases with decrease in stressed area. Calculations of the stress-area integral for the loading arrangement show good agreement with weakest link predictions.

In this paper, a testing device for gas cylinder, which is composed of PC, data acquisition card on USB bus technology and the application software compiled on the labVIEW platform, is designed on the basis of virtual instrument technology. The assembly and disassembly of the cylinder plug, weighing, temperature measuring, being irrigated upright, and hydraulic pressure testing are all realized. This device has been put into use with highly practical effect.

Most of currently employed laparoscopes use a single and non-tunable solid lens to visualize the surgical environment during minimal invasive interventions. These devices are limited due to the loss of depth perception, fixed view direction and narrow field-of-view (FOV). In this study, a three-dimensional deformable liquid lens array with adaptive focusing and directional view capability is developed. Miniature liquid lenses sealed by deformable membranes are arranged on a flexible substrate. During the operation, the flexible substrate where the liquid lenses reside is driven by hydraulic pressure and bulges into different curvatures, which results in the maximal angular difference of the optical axes of individual lenses in the array from 0° to 45°. The focal length of each lens can be simultaneously tuned from 64.3mm to 2.1mm. At the directional view of 45° and focal length of 2.1mm, the overall FOV exceeds 150°. This work promises the potential of directional and wide angle laparoscopic imaging where space constraint is a concern.

Recently, a new hydraulic-pressure assisted deep-drawing process was invented by the author, this new method having evolved from a hydraulic device for deep-drawing with the blank-holder force approximately proportional to the punch force, developed successfully earlier. The present method also generates a hydraulic pressure proportional to the punch force, although the present hydraulic pressure, is greater. The blank-holding force in the present case is also dependent on the hydraulic pressure, but it does not vary in a simple manner. In addition, the present process uses the hydraulic pressure to push the periphery of the flange of the cup being drawn radially inwards in this way the hydraulic pressure augmenting the punch force and making it possible to achieve greater draw ratios than those possible in the simple deep-drawing process. Since the hydraulic pressure depends on the punch force, both the punch force and the pressure are automatically coordinated, thereby eliminating the need for any control system to coordinate them. The present process also provides the blank-holding force automatically, requiring only a single-action press. Tooling was designed and constructed for drawing 36 mm diameter cups at draw ratios of about 3.0 with the present method. Tests conducted with annealed aluminium blanks of thickness 1 mm were successful at a draw ratio of 3.11, the latter draw ratio being limited by the present tooling. With the full potential of the process utilized and new tooling constructed to accommodate larger diameter blanks, greater draw ratios may be achieved. This paper presents the underlying principle of the process, the design and development of the tooling and the experimental results obtained in the use of the tooling.

Though conventional hydraulic disc brake has better braking steadiness, it also has poor braking efficiency factor. As a fact, the conventional hydraulic disc brake has no large-scale application to heavy duty vehicle. A novel wedge disc brake is presented in this paper, which not only has the special characteristic of self-reinforcement, but also has better braking steadiness just like conventional disc brake. Firstly, the self-reinforcement principle of this kind of wedge disc brake is analyzed and concluded. The reasonable angle of wedge block is calculated and chosen according to the demand of self-reinforcement and unexpected self-lock phenomena. Based on that, the braking efficiency factor is derived from the wedge angle and the friction coefficient between the wedge block and brake disc. After that, the mechanical structure of designed wedge disc brake is presented, then some material strength of the components are revised. In order to validate this designed novel wedge disc brake, a AMESim vehicle model with Simulink wedge disc brake model are built. Several items such as the effect of self-reinforcement and reset of wedge block are simulated. Simulation results show that this novel wedge disc brake can generate the same brake force only at nearly one third multiple hydraulic pressure of conventional disc brake.

Aiming at problem of force condition of vane in high pressure vane pump, through analyzing hydraulic pressure forces, motion inertia forces and contacting reaction forces which were exerted by stator and rotor in vane, dynamic model of force in inlet area was built. Contacting reaction forces were solved at two cases of considering vane's shape, thickness and didn't, a series of variation curves of contacting reaction forces were obtained by simulation. Through analyzing and contrasting, great differences were found at two cases, and sometimes much effect will be generated if vane's shape and thickness is ignored. Force condition of vane with arc top is better than Single-sided sloping vane whose top isn't arc.

In this study, in order to investigate the wave-induced buoyancy effects, experimental studies were conducted on pontoon-type floating structures. A series of small-scale tests with various wave cases were performed on the pontoon models. A total of four small-scale pontoon models with different lateral shapes and bottom details were fabricated and tested under the five different wave cases. Six hydraulic pressure gauges were attached to the bottom surfaces of the pontoon models and the wave-induced hydraulic pressure was measured during the tests. Finally, hydraulic pressures subjected to the bottoms of the pontoon models were compared with each other. As the results of this study, it was found that the wave-induced hydraulic pressures at the bottom were dependent on the wave period as well as the wave height. The hydraulic pressures linearly increased according to the wave height and period. However, in case of long wave periods, the wave-induced hydraulic pressure no longer increased. Also, it was found that whereas the waffled bottom shape hardly influenced the wave-induced hydraulic pressure, the prismoid lateral shape significantly influenced the wave-induced hydraulic pressure subjected on the bottoms of floating structures. The air gap effects of the prismoid shape contribute to decreasing the wave-induced hydraulic pressure due to absorption of wave impact energy.

In order to suppress pressure pulsation in hydraulic lines, bladder type accumulators are used widely. Especially, in-line accumulators whose bladder gas pressure is adjusted appropriately show outstanding performances. The effective range of the bladder gas pressure, however, is quite narrow and the performances drastically reduce according to even a slight change of mean hydraulic pressure, length and diameter of pipe, etc. In the present paper, firstly, the fundamental characteristics of the in-line accumulator have been investigated in detail by using frequency analysis. Secondly, a self-adjustable hydraulic pulsation suppressing system has been developed by attaching pressure transducers, a board computer with a universal pulse processor, hydraulic to pneumatic converter, etc. to the accumulator. As the result, it has been confirmed that the developed system is remarkably effective in suppression of the pulsation when mean hydraulic pressure changes frequently.