Pressure control method and device innovative design for deep oil in-situ exploration and coring

Deep oil exploration coring technology cannot accurately maintain the in-situ pressure and temperature of samples, which leads to a distortion of deep oil and gas resource reserve evaluations based on conventional cores and cannot guide the development of deep oil and gas resources on Earth. The fundamental reason is the lack of temperature and pressure control in in-situ coring environments. In this paper, a pressure control method of a coring device is studied. The theory and method of deep intelligent temperature-pressure coupling control are innovatively proposed, and a multifield coupling dynamic sealing model is established. The optimal cardinality three term PID (Proportional-Integral-Differential) intelligent control algorithm of pressure system is developed. The temperature-pressure characteristic of the gas-liquid two-phase cavity is analyzed, and the pressure intelligent control is carried out based on three term PID control algorithms. An in-situ condition-preserved coring (ICP-Coring) device is developed, and an intelligent control system for the temperature and pressure of the coring device is designed and verified by experiments. The results show that the temperature-pressure coupling control system can effectively realize stable sealing under temperature-pressure fields of 140 MPa and 150 °C. The temperature-pressure coupling control method can accurately realize a constant pressure inside the coring device. The maximum working pressure is 140 MPa, and the effective pressure compensation range is 20 MPa. The numerical simulation experiment of pressure system control algorithm is carried out, and the optimal cardinality and three term coefficients are obtained. The pressure steady-state error is less than 0.01%. The method of temperature-pressure coupling control has guiding significance for coring device research, and is also the basis for temperature-pressure decoupling control in ICP-Coring.

Flexible polydimethylsiloxane pressure sensor with micro-pyramid structures and embedded silver nanowires:A novel application in urinary flow measurement

Flexible pressure sensors are lightweight and highly sensitive,making them suitable for use in small portable devices to achieve precise measurements of tiny forces.This article introduces a low-cost and easy-fabrication strategy for piezoresistive flexible pressure sensors.By embedding silver nanowires into a polydimethylsiloxane layer with micro-pyramids on its surface,a flexible pressure sensor is created that can detect low pressure (17.3 Pa) with fast response (<20 ms) and high sensitivity (69.6 mA kPa-1).Furthermore,the pressure sensor exhibits a sensitive and stable response to a small amount of water flowing on its surface.On this basis,the flexible pressure sensor is innovatively combined with a micro-rotor to fabricate a novel urinary flow-rate meter (uroflowmeter),and results from a simulated human urination experiment show that the uroflowmeter accurately captured all the essential shape characteristics that were present in the pump-simulated urination curves.Looking ahead,this research provides a new reference for using flexible pressure sensors in urinary flow-rate monitoring.

Intraocular pressure before and after capsulorhexis using two viscoelastic substances and two surgical approaches in enucleated porcine eyes

AIM:To investigate the influence of ophthalmic viscoelastic devices(OVDs)and different surgical approaches on the intraocular pressure(IOP)before and after creation of the curvilinear circular capsulorhexis(CCC)as a measure for anterior chamber stability during this maneuver.METHODS:Prospective experimental WetLab study carried out on enucleated porcine eyes.IOP was measured before and after CCC with the iCare Rebound tonometer(iCare ic200;iCare Finland Oy,Vantaa,Finland).The OVDs used were a cohesive one[Z-Hyalin,Carl Zeiss Meditec AG,Germany;hyaluronic acid(HA)]and a dispersive[Z-Celcoat,Carl Zeiss Meditec AG,Germany;hydroxy propylmethylcellulosis(HPMC)].The CCC was created using Utrata forceps or 23 g microforceps in different combinations with the OVDs.RESULTS:Using the Utrata forceps the IOP dropped from 63.65±6.44 to 11.25±3.63 mm Hg during the CCC.The use of different OVDs made no difference.Using the 23 g microforceps the IOP dropped from 65.35±8.15 to 36.55±6.09 mm Hg.The difference between IOP drop using either Utrata forceps or 23 g microforceps was highly significant regardless of the OVD used.CONCLUSION:Using the sideport for the creation of the capsulorhexis leads to a lesser drop in IOP during this maneuver compared to the main incision in enucleated porcine eyes.The use of different OVD has no significant influence on IOP drop.

Intraocular pressure control of a novel glaucoma drainage device-in vitro and in vivo studies

AIM：To evaluate the intraocular pressure（IOP）control of an artificial trabeculum drainage system（ATDS）,a newly designed glaucoma drainage device,and postoperative complications in normal rabbit eyes.METHODS：Pressure drops in air and fluid of 30 ATDS were measured after being connected to a closed manometric system.Twenty of them were then chosen and implanted randomly into the eyes of 20 rabbits.Postoperative slitlamp,gonioscopic examination and IOP measurements were recorded periodically.Ultrasound biomicroscopy and B-scan ultrasonography were also used to observe the complications.Eyes were enucleated on day 60.RESULTS：Pressure drops of 4.6-9.4 mm Hg were obtained at physiological aqueous flow rates in the tests in vitro.The average postoperative IOP of the experimental eyes（11.6-12.8 mm Hg）was lower than the controls significantly（P〈0.05）at each time point.Complications of hemorrhage（n=1）,cellulosic exudation（two cases）and local iris congestion（two cases）were observed.The lumina of the devices were devoid of obstructions in all specimens examined and a thin fibrous capsule was found around the endplate.CONCLUSION：ATDS reduce IOP effectively.However,further studies on the structure are needed to reduce complications.

The effects of a new shape-memory alloy interspinous process device on the distribution of intervertebral disc pressures in vitro

This study was designed to measure the pressure distribution of the intervertebral disc under different degrees of distraction of the interspinous process, because of a suspicion that the degree of distraction of the spinous process may have a close relationship with the disc load share. Six human cadaver lumbar spine L2-L5 segments were loaded in flexion, neutral position, and extension. The L3-L4 disc load was measured at each position using pressure measuring films. Shape-memory interspinous process implants （SMID） with different spacer heights, ranging in size from 10 to 20 mm at 2 mm increments, were used. It was found that a SMID with a spacer height equal to the distance of the interspinous process in the neutral position can share the biomechanical disc load without a significant change of load in the anterior annulus. An interspinous process stabilizing device （IPD） would not be appropriate to use in those cases with serious spinal stenosis because the over-distraction of the interspinous process by the SMID would lead to overloading the anterior annulus which is a recognized cause of disc degeneration.

A wireless-communication-based measurement of gas pressure with capsule-slime sealing device

To solve the existing problems of imperfect sealing and the inaccurate measurement of gas pressure in traditional sealing,the present study builds a new model of capsule-slime sealing device based on wireless pressure gauge.The new sealing device is mainly composed of two sets of capsules,a capsule connecting piece and a slime part,measures the pressure through the wireless communication technology,and seals through chemical reaction in the capsule,which generates gas to expand the capsule and extrude the pre-stored slime.Two methods of extruding pre-stored slime are proposed:in the first method,transverse force is generated by the expansion of the capsules at both ends,pushing the capsules toward the middle through the chute and squeezing the pre-stored slime out;in the second,high-pressure gas generated in the capsules is led into the expansion tube,which is inserted into the storage tube,squeezing it and letting the slime out to complete the sealing process.Then the research studies the effect of sealing under the condition of drilling with the structure of slime storage tube.The results indicate that the maximum standing time of slime wrapped in metal net is 2 h,instead of the expected 10 d,failing to meet the sealing requirements.When the slime viscosity is 1200–3000 m Paás in the structure of slime storage tube,the best viscosity of slime is achieved and can simulate sealing the drilling hole(5–4,4–2.36,2.36–1.18,1.18–0.15 mm in diameter),as well as the gap caused by mixed sand accumulation.

Modern Monitoring Intraocular Pressure Sensing Devices Based on Application Specific Integrated Circuits

Glaucoma is a neurodegenerative condition that is the leading cause of irreversible blindness worldwide. Elevated intraocular pressure (IOP) is the main risk factor for the development and progression of the disease. Methods to lower IOP remain the first line treatments for the condition. Current methods of IOP measurement do not permit temporary noninvasive monitoring 24-hour IOP on a periodic basis. Ongoing research will in time provide a means of developing a device that will enable continuous or temporary monitoring of IOP. At present a device suitable for clinical use is not yet available.This review contains a description of different devices currently in development for measuring IOP: soft contact lens, LC resonant circuits and on-chip sensing devices. All of them use application-specific integrated circuits (ASICS) to process the measured signals and send them to recording devices. Soft contact lens devices are based on an embedded strain gauge, LC circuits vary their resonance frequency depending on the intraocular pressure (IOP) and, finally, on-chip sensing devices include an integrated microelectromechanical sensor (MEMS). MEMS are capacitors whose capacity varies with IOP. These devices allow for an accurate IOP measurement (up to +/– 0.2 mm Hg) with high sampling rates (up to 1 sample/min) and storing 1 week of raw data. All of them operate in an autonomous way and even some of them are energetically independent.

Design of New Elevator Pressure Guide Plate and Its Test Device

Pressure guide plate plays a certain role in the safe operation of elevator.Based on understanding the respective performance of new and old pressure guide plates,this paper analyses the problems existing in the original pressure guide plate.It also conducts stress analysis according to the function of pressure guide plate on elevator,and designs a new type of pressure guide plate combined with technological capability and equipment.According to the stress characteristics,a test device is designed and a comparative test is made between the new type of pressure guide plate and the old in order to test the reliability of the new type of pressure guide plate.The test proves that the new pressure guide plate of elevator can meet the requirements of product use and safe operation of elevator products.

Study on Measuring Device for Bearing Clearance of Hemisphere Dynamic Pressure Motor

The clearance of the hemisphere dynamic pressure motor is small and difficult to measure, the measurement method of micro clearance is studied. The shortcomings of the original measurement method are analyzed, and a clearance measuring device for the hemisphere dynamic pressure motor is designed, which improves the measurement efficiency and stability.

Flexible and electrically robust graphene-based nanocomposite paper with hierarchical microstructures for multifunctional wearable devices

Multifunctional and flexible wearable devices play a crucial role in a wide range of applications,such as heath monitoring,intelligent skins,and human-machine interactions.Developing flexible and conductive materials for multifunctional wearable devices with low-cost and high efficiency methods are highly desirable.Here,a conductive graphene/microsphere/bamboo fiber(GMB)nanocomposite paper with hierarchical surface microstructures is successfully fabricated through a simple vacuum-assisted filtration followed by thermo-foaming process.The as-prepared microstructured GMB nanocomposite paper exhibits not only a high volume electrical conductivity of~45 S/m but also an excellent electrical stability(i.e.,relative changes in resistance are less than 3%under stretching,folding,and compressing loadings)due to its unique structure features.With this microstructured nanocomposite paper as active sensing layer,microstructured pressure sensors with a high sensitivity(-4 kPa^(-1)),a wide sensing range(0–5 kPa),and a rapid response time(about 140 ms)are realized.In addition,benefitting from the outstanding electrical stability and mechanical flexibility,the microstructured nanocomposite paper is further demonstrated as a low-voltage Joule heating device.The surface temperature of the microstructured nanocomposite paper rapidly reaches over 80℃ when applying a relatively low voltage of 7 V,indicating its potential in human thermotherapy and thermal management.

Parameter optimization and experiment of the negative pressure precision seed-metering device for wheat

In order to ensure the most reasonable distribution of wheat seeds in the field to improve seeding quality and uniformity,a set of negative pressure precision seed-metering device was designed,which shares a hollow shaft.Every seed-metering device can sow two rows of wheat.By the STAR-CCM+,the analysis of nephogram,vectogram and streamline graph showed that more ideal structural parameters of the seed-metering device are 0.5 mm width of the slit sucking seed(WSS),150-200 mm diameter of the seed-metering disc(DSD),2.0 mm axial depth of air chamber in the seed-metering disc(ADS),and arc-shaped cross-section shape of the ring groove sucking seed(CSGS).Single-factor test on the JPS-12 test-bed analyzed the influence of the CSGS,WSS,DSD,and ADS on the qualified index(Iq),multiple index(Imul),miss index(Imiss)and coefficient of variation of qualified seed spacing(CV).Through the orthogonal on the JPS-12 test-bed,it is found that the influence of vacuum negative pressure and seed-metering device shaft speed is significant on the Iq,Imiss and Imul.Based on these,the structural parameters of the seed-metering device were optimized.The DSD is 180 mm,the WSS is 0.7 mm,the ADS is 2.5 mm,and the CSGS is arc-shaped.The optimization seed-metering device was tested on the JPS-12 test-bed.The Iq is 86.66%,the Imiss is 5.09%,the Imul is 8.25%,and the CV is 24.50%.These testing results fully coincide with the standard JB/T 10293-2013 Specifications of single seed drill(precision drill).The seed-metering device meets fully the requirements for wheat precision seeding.

Development of a 100 MPa water–gas two-phase fluid pressurization device

This paper introduces a 100 MPa water gas twophase fluid pressurization device.The device can provide 100 MPa gas pressure and 200 MPa liquid pressure for small volume(<20 mL)high-pressure experimental devices.This device can make the pressure control independent of the temperature control without changing the material components of the system.The resolution of this device in adjusting the pressure is±0.2 MPa in the process of boosting and depressurizing.This pressure boosting device generates very little vibration during work and it can be used in experiments with strict requirements on vibration.As a thermodynamic parameter,pressure has a great influence on matter.In the field of experimental geochemistry,pressure is not only an experimental method and an extreme condition but an important physical parameter independent of temperature and chemical composition.

Active earth pressure for subgrade retaining walls in cohesive backfills with tensile strength cut-off subjected to seepage effects

The commonly used Mohr-Coulomb(M-C) failure condition has a limitation that it overestimates the tensile strength of cohesive soils. To overcome this limitation, the tensile strength cut-off was applied where the predicted tensile strength is reduced or eliminated. This work then presented a kinematical approach to evaluate the active earth pressure on subgrade retaining walls in cohesive backfills with saturated seepage effects. An effective rotational failure mechanism was constructed assuming an associative flow rule. The impact of seepage forces, whose distribution is described by a closed-form solution, was incorporated into the analysis. The thrust of active earth pressure was derived from the energy conservation equation, and an optimization program was then coded to obtain the most critical solution. Several sets of charts were produced to perform a parameter analysis. The results show that taking soil cohesion into account has a distinct beneficial influence on the stability of retaining walls, while seepage forces have an adverse effect. The active earth pressure increases when tensile strength cut-off is considered, and this increment is more noticeable under larger cohesion.

Influence of confi ning pressure and impact loading on mechanical properties of amphibolite and sericite-quartz schist

In order to investigate the dynamic mechanical properties of amphibolite and sericite-quartz schist under confi ning pressure, two rocks are subjected to impact loadings with different strain rates and confi ning pressures by using split Hopkinson pressure bar equipment with a confi ning pressure device. Based on the experimental results, the stress-strain curves are analyzed and the effects of confi ning pressure and strain rates on the dynamic compressive strength, peak strain and failure mode are summarized. The results show that:(1) The characteristics of two rocks in the ascent stage of the stressstrain curve are basically the same, but in the descent stage, the rocks gradually show plastic deformation characteristics as the confi ning pressure increases.(2) The dynamic compressive strength and peak strain of two rocks increase as the strain rate increases and the confi ning pressure effects are obvious.(3) Due to the effect of confi ning pressure, the normal stress on the damage surface of the rock increases correspondingly, the bearing capacity of the crack friction exceeds the material cohesion and the slippage of the fractured rock is controlled, which all lead to the compression and shear failure mode of rock. The theoretical analysis and experimental methods to study the dynamic failure mode and other related characteristics of rock are useful in developing standards for engineering practice.

Fedora-type magnetic compression anastomosis device for intestinal anastomosis

BACKGROUND Although previous studies have confirmed the feasibility of magnetic compression anastomosis(MCA),there is still a risk of long-term anastomotic stenosis.For traditional MCA devices,a large device is associated with great pressure,and eventually increased leakage.AIM To develop a novel MCA device to simultaneously meet the requirements of pressure and size.METHODS Traditional nummular MCA devices of all possible sizes were used to conduct ileac anastomosis in rats.The mean(±SD)circumference of the ileum was 13.34±0.12 mm.Based on short-and long-term follow-up results,we determined the appropriate pressure range and minimum size.Thereafter,we introduced a novel“fedora-type”MCA device,which entailed the use of a nummular magnet with a larger sheet metal.RESULTS With traditional MCA devices,the anastomoses experienced stenosis and even closure during the long-term follow-up when the anastomat was smaller thanΦ5 mm.However,the risk of leakage increased when it was larger thanΦ4 mm.On comparison of the different designs,it was found that the“fedora-type”MCA device should be composed of aΦ4-mm nummular magnet with aΦ6-mm sheet metal.CONCLUSION The diameter of the MCA device should be greater than 120%of the enteric diameter.The novel“fedora-type”MCA device controls the pressure and optimizes the size.

Plasma skincare device based on floating electrode dielectric barrier discharge

A portable skincare plasma-device with a rechargeable battery is presented here. The device comprises two pads made of thin polyimide film as the dielectric layer, namely, the dielectric barrier discharge pad(DBD-pad) for skin-touch and a capacitive ground-pad(G-pad) for hand holding. High AC voltage of approximately 1 kV with frequency of 40 kHz is induced in the DBD-pad that contacts the skin, which serves as the floating electrode, while low voltage is induced on the G-pad. Considering the requirement for impedance matching between the DBDpad capacitance and the inverter along with the need for low skin current less than approximately 5 mA for electrical safety, the electrode area of the DBD-pad is minimized to be smaller than that of the G-pad.

Use of the impedance threshold device in cardiopulmonary resuscitation

Although approximately one million sudden cardiac deaths occur yearly in the US and Europe,cardiac arrest (CA)remains a clinical condition still characterized by a poor prognosis.In an effort to improve the cardio- pulmonary resuscitation(CPR)technique,the 2005 American Heart Association(AHA)Guidelines for CPR gave the impedance threshold device(ITD)a Class IIa recommendation.The AHA recommendation means that there is strong evidence to demonstrate that ITD enhances circulation,improves hemodynamics and increases the likelihood of resuscitation in patients in CA.During standard CPR,venous blood return to the heart relies on the natural elastic recoil of the chest which creates a transient decrease in intrathoracic pressure.The ITD further decreases intrathoracic pressure by preventing respiratory gases from entering the lungs during the decompression phase of CPR. Thus,although ITD is placed into the respiratory circuit it works as a circulatory enhancer device that provides its therapeutic benefit with each chest decompression. The ease of use of this device,its ability to be incor- porated into a mask and other airway devices,the absence of device-related adverse effects and few requirements in additional training,suggest that ITD may be a favorable new device for improving CPR efficiency.Since the literature is short of studies with clinically meaningful outcomes such as neurological outcome and long term survival,further evidence is still needed.

Autologous mesenchymal stem cells applied on the pressure ulcers had produced a surprising outcome in a severe case of neuromyelitis optica

Recent studies provided evidence that mesenchymal stem cells（MSCs） have regenerative potential in cutaneous repair and profound immunomodulatory properties making them a candidate for therapy of neuroimmunologic diseases. Neuromyelitis optica（NMO） is an autoimmune, demyelinating central nervous system disorder characterized by a longitudinally extensive spinal cord lesion. A 46-year-old male diagnosed with NMO had relapses with paraplegia despite treatment and developed two stage IV pressure ulcers（PUs） on his legs. The patient consented for local application of autologous MSCs on PUs. MSCs isolated from the patient＇s bone marrow aspirate were multiplied in vitro during three passages and embedded in a tridimensional collagen-rich matrix which was applied on the PUs. Eight days after MSCs application the patient showed a progressive healing of PUs and improvement of disability. Two months later the patient was able to walk 20 m with bilateral assistance and one year later he started to walk without assistance. For 76 months the patient had no relapse and no adverse event was reported. The original method of local application of autologous BM-MSCs contributed to healing of PUs. For 6 years the patient was free of relapses and showed an improvement of disability. The association of cutaneous repair, sustained remission of NMO and improvement of disability might be explained by a promotion/optimization of recovery mechanisms in the central nervous system even if alternative hypothesis should be considered. Further studies are needed to assess the safety and efficacy of mesenchymal stem cells in NMO treatment.

The properties of Sn-Zn-Al-La fusible alloy for mitigation devices of solid propellant rocket motors

The Al and La elements are added to the Sn9Zn alloy to obtain the fusible alloy for the mitigation devices of solid propellant rocket motors. Differential scanning calorimetry(DSC), metallographic analysis,scanning electron microscopy(SEM), energy dispersive spectroscopy(EDS), tensile testing and fracture analysis were used to study the effect of Al and La elements on the microstructure, melting characteristics, and mechanical properties of the Sn9Zn alloy. Whether the fusible diaphragm can effectively relieve pressure was investigated by the hydrostatic pressure at high-temperature test. Experimental results show that the melting point of the Sn9Zn-0.8Al0·2La and Sn9Zn-3Al0·2La fusible alloys can meet the predetermined working temperature of ventilation. The mechanical properties of those are more than 35% higher than that of the Sn9Zn alloy at-50°C-70°C, and the mechanical strength is reduced by 80% at 175°C. It is proven by the hydrostatic pressure at high-temperature test that the fusible diaphragm can relieve pressure effectively and can be used for the design of the mitigation devices of solid propellant rocket motors.

Research on experiment and calculation of foam bursting device

This research presents experimental data on mechanical foam bursting device,based on the high speed of air fluid impinging insidethe foam bursting device,foam bubbles disrupted as a consequence of pressures changed very quickly as shear force and their impact forces.Experimental data on foam-bursting capacity have been presented.Designed device can provide effective foam bursting on collapse foam.