Maximum Effective Hole Mathematical Modei and Exact Solution for Commingled Reservoir

The maximum effective hole-diameter mathematical modei describing the flow of slightly compressible fluid through a commingled reservoir was solved rigorously with consideration of wellbore storage and different skin factors. The exact solutions for wellbore pressure and the production rate obtained from layer j for a well production at a constant rate from a radial drainage area with infinite and constant pressure and no flow outer boundary condition were expressed in terms of ordinary Bessel functions. These solutions were computed numerically by the Crump's numerical inversion method and the behavior of systems was studied as a function of various reservoir parameters. The modei was compared with the real wellbore radii modei. The new modei is numerically stable when the skin factor is positive and negative, but the real wellbore radii modei is numerically stable only when the skin factor is positive.

Interaction between a screw dislocation and an elliptical hole with two asymmetrical cracks in a one-dimensional hexagonal quasicrystal with piezoelectric effect

The interaction between a screw dislocation and an elliptical hole with two asymmetrical cracks in a one-dimensional(1 D) hexagonal quasicrystal with piezoelectric effect is considered. A general formula of the generalized stress field, the field intensity factor, and the image force is derived, and the special cases are discussed. Several numerical examples are given to show the effects of the material properties and the dislocation position on the field intensity factors and the image forces.

Hawking effect and quantum nonthermal radiation of an arbitrarily accelerating charged black hole using a new tortoise coordinate transformation

Using a new tortoise coordinate transformation, this paper investigates the Hawking effect from an arbitrarily accelerating charged black hole by the improved Damour-Ruffini method. After the tortoise coordinate transformation, the Klein-Gordon equation can be written as the standard form at the event horizon. Then extending the outgoing wave from outside to inside of the horizon analytically, the surface gravity and Hawking temperature can be obtained automatically. It is found that the Hawking temperatures of different points on the surface are different. The quantum nonthermal radiation characteristics of a black hole near the event horizon is also discussed by studying the Hamilton-Jacobi equation in curved spacetime and the maximum overlap of the positive and negative energy levels near the event horizon is given. There is a dimensional problem in the standard tortoise coordinate and the present results may be more reasonable.

Surface Effects on the Scatter of SH-Wave by a Shallow Buried the Elliptical Hole

The methods of complex function, multi-polar coordinate system, and conformal mapping are used to solve dynamic stress concentration factor. The surface elasticity theory is applied to obtain the stress boundary conditions on the surface. The effects of frequency and the ration of the major and minor axis of the ellipse on the dynamic stress concentration factor around the elliptical nano-hole are discussed in detail. When the size of elliptical hole shrinks to nanometers, the numerical results show that the surface effect has a significant effect on the scattering of SH-wave.

The Casimir effect of Reissner-NordstrSm black hole

The stress tensor of a massless scalar field satisfying a mixed boundary condition in a （1 ＋ 1）-dimensional Reissner- Nordstrom black hole background is calculated by using Wald＇s axiom. We find that Dirichlet stress tensor and Neumann stress tensor can be deduced by changing the coefficients of the stress tensor calculated under a mixed boundary condition. The stress tensors satisfying Dirichlet and Neumann boundary conditions are discussed. In addition, we also find that the stress tensor in conformal flat spacetime background differs from that in flat spacetime only by a constant.

Charging Effect in Plasma Etching Mask of Hole Array

It has already been found that the round shape of holes can be changed into hexagonal shape during plasma etching processes.This work aims to understand the mechanism behind such a shape change using particle simulation method.The distribution of electric field produced by electrons was calculated for different heights from the mask surface.It is found that the field strength reaches its maximum around a hole edge and becomes the weakest between two holes. The field strength is weakened as moving away from the surface.The spatial distribution of this electric field shows obvious hexagonal shape around a hole edge at some distances from the surface. This charging distribution then affects the trajectories of ions that fall on a mask surface so that the round hole edge is etched to become a hexagonal hole edge.The changing of this hole shape will again alter the spatial distribution of electric field to enhance the charging effect dynamically.

Interaction effects on heat conduction and thermal stress in an infinite elastic plane with two circular holes

Numerous researches have focused on the physical behavior of an elastic material in the vicinity of a single hole under the assumption that the interaction effects arising from the introduction of multiple holes remain negligible if the holes are placed sufficiently far from each other.In an effort to understand hole interaction effects on heat conduction and thermal stress,we consider the case when two circular holes are embedded in an infinite elastic material and use complex variable methods together with numerical analysis to obtain solutions describing temperature and elastic fields in the vicinity of the two circular holes.The results indicate that the interaction effects on temperature distribution and stress strongly depend on the relative size of the two holes and the distance placed between them but not on the actual size of the holes.

Analysis of the Effect of Air Hole Diameter and Lattice Pitch in Optical Properties for Hexagonal Photonic Crystal Fiber

We have investigated the different optical properties such as confinement loss, waveguide dispersion of a five rings hexagonal photonic crystal fiber under varied air hole diameter (d), lattice pitch (Λ), and air hole diameter to lattice pitch ratio for three different materials fused quartz glass, borosilicate glass and sapphire glass. We observed low confinement loss and high negative dispersion at higher d/Λ. Achieving high d/Λ can be done in two ways: increasing the air hole diameter or decreasing the lattice pitch. It has been observed, increasing the air hole diameter has significant effect over reducing lattice pitch in achieving low confinement loss. On the other hand, decreasing the lattice pitch over increasing the air hole diameter has significant effect in achieving high negative dispersion. It has also been found that, effective refractive index (neff) decreases significantly when lattice pitch decreases.

Effects of Homogeneous Plasma on Strong Gravitational Lensing of Kerr Black Holes

Considering the Kerr black hole surrounded by a homogeneous unmagnetized plasma medium, we study the strong gravitational lensing on the equatorial plane of the Kerr black hole. It is found that the presence of the uniform plasma can increase the photon-sphere radius r_{／rm ps}, the coefficients ／bar{a} and ／bar{b}, the angular position of the relativistic images （／theta_{／infty}）, the deflection angle ／alpha（／theta） and the angular separation s. However, the relative magnitude r_{／rm m} decreases in the presence of the uniform plasma medium. It is also shown that the impact of the uniform plasma on the effect of strong gravitational lensing becomes smaller as the spin of the Kerr black hole increases in the prograde orbit （a〉0）. In particular, for the extreme black hole （a=0.5）, the effect of strong gravitational lensing in the homogeneous plasma medium is the same as the case in vacuum for the prograde orbit.

Analysis of Film Cooling Effectiveness on Shaped Hole and Antivortex Hole

Film cooling is introduction of a secondary fluid （coolant or injected fluid） at one or more discrete locations along a surface exposed to a high temperature environment to protect that surface not only in the immediate region of injection but also downstream region. This paper numerically investigated the film cooling effectiveness on two types of hole geometries which are cut-shaped hole and antivortex hole. The 3D computational geometries are modeled with a single 30 deg angled hole on a flat surface. The different blowing ratios of 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5,5 and k-Epsilon turbulence model are used in this study. A two dimensional distribution of film cooling effectiveness in the downstream region of the cooling hole is performed. A comparison of spanwise averaged effectiveness is also performed in the field starts from center point of hole to X/D=-30.

Analysis of impact pressure,rock-breaking effect,and ground vibration induced by the disposable CO_(2)fracturing tube

The technology of expansion fracturing with liquid CO_(2)(EFLCO_(2))has attracted increasing attention due to reduced vibration and damage.The disposable fracturing tube has been developed and is gradually replacing the Cardox tube.However,there is a lack of impact pressure testing of disposable tubes under real working conditions,selection of gas explosion design parameters,and systematic analysis of blasting vibration.This limitation has constrained the widespread application of disposable fracturing tubes in engineering.A joint monitoring of the pressure-time curves in the disposable tubes and boreholes was conducted.The rock-breaking effect of varying hole spacing parameters in the EFLCO_(2)design was analyzed,and a systematic study was carried out on the vibration peak value,frequency,and energy characteristics.The results show that(1)the pressure distribution characteristics,stress peak value,and duration in the disposable tubes are different from those of Cardox tubes,which show multi-peak distribution,low-pressure peak value,and short duration.The correlation between the pressure in the disposable tube,filling pressure,and liquid CO_(2)weight is established,and a theoretical calculation method for the borehole wall pressure is proposed;(2)The hole spacing in rocks of different hardness is suggested;and(3)At the same scale distance,the peak particle velocity(PPV)caused by EFLCO_(2)(PPVCO_(2))is significantly smaller than that caused by blasting(PPVexplosive).The ratio of PPVexplosive to PPVCO_(2)is a power function related to scale distance,and a distance-related zonality exist in this relationship.The frequency composition of the vibration signal caused by EFLCO_(2)is relatively simple with a narrow frequency band.Its PPV and energy are mainly concentrated in the low-frequency band.This research contributes to the optimization of disposable fracturing tubes,gas explosion design,and vibration hazard control.

后路单开门钉板固定结合Key-hole技术在混合型颈椎病患者中的应用效果

目的:分析后路单开门钉板固定结合Key-hole技术在混合型颈椎病患者中的应用效果。方法:采用前瞻性分析法,以随机数表法将2021年6月至2023年6月濮阳市人民医院120例混合型颈椎病患者分为对照组和观察组,各60例。对照组患者采用后路单开门钉板固定治疗,观察组患者采用后路单开门钉板固定结合Key-hole技术治疗。对两组患者术前和术后3个月的JOA评分、JOA评分改善率、Cobb角、ROM、颈椎肌张力及术后3个月的并发症情况进行比较。结果:与对照组相比,术后观察组的JOA评分、JOA评分改善率均升高,术后观察组的Cobb角、ROM、颈椎肌张力均升高,术后3个月观察组的神经根症状总有效率升高,术后3个月内观察组的并发症总发生率降低,差异有统计学意义(P<0.05)。结论:后路单开门钉板固定结合Key-hole技术能够有效缓解混合型颈椎病患者的颈髓、神经根压迫,改善颈髓、神经根功能,且可减少并发症发生。

微创Key-Hole手术与开放ACDF手术治疗神经根型颈椎病的疗效对比

目的对比微创脊柱内镜下颈椎后路开窗减压髓核摘除术(Key-Hole)与开放颈椎前路椎间盘切除减压术(ACDF)治疗神经根型颈椎病(CSR)的疗效。方法选择2019年1—12月我院治疗的60例CSR患者,按随机数字表法将其分为2组各30例。对照组采用开放ACDF手术治疗,观察组采用微创Key-hole手术治疗,比较2组临床指标、疼痛程度及邻近节段活动度。结果观察组卧床及住院时间短于对照组,术中出血量少于对照组,术后视觉模拟评分法(VAS)评分及邻近上位、下位节段活动度低于对照组,日本骨科协会评估(JOA)评分高于对照组,均有统计学差异(P<0.05)。结论CSR患者采用微创Key-hole手术治疗是安全可行的,损伤小、疼痛轻,可满足患者早日下床活动,减少邻近关节退变,保护颈椎结构功能。

Kerr Black Hole Geometry Leading to Dark Matter and Dark Energy via E-Infinity Theory and the Possibility of a Nano Spacetime Singularities Reactor

The present paper is basically a synthesis resulting from incorporating Kerr spinning black hole geometry into E-infinity topology, then letting the result bares on the vacuum zero point Casimir effect as well as the cosmic dark energy and dark matter density. In E-infinity theory a quantum particle is represented by a Hausdorff dimension Φ where Φ =2/(√5+1) . The quantum wave on the other hand is represented by Φ2 . To be wave and a particle simultaneously intersection theory leads us to?(Φ) (Φ)2= Φ3 which will be shown here to be twice the value of the famous Casimir force of the vacuum for a massless scalar field. Thus in the present work a basically topological interpretation of the Casimir effect is given as a natural intrinsic property of the geometrical topological structure of the quantum-Cantorian micro spacetime. This new interpretation compliments the earlier conventional interpretation as vacuum fluctuation or as a Schwinger source and links the Casimir energy to the so called missing dark energy density of the cosmos. From the view point of the present work Casimir pressure is a local effect acting on the Casimir plates constituting the local boundary condition while dark energy is nothing but the global combined effect of infinitely many quantum waves acting on the M&#246bius-like boundary of the holographic boundary of the entire universe. Since this higher dimensional M&#246bius-like boundary is one sided, there is no outside to balance the internal collective Casimir pressure which then manifests itself as the force behind cosmic expansion, that is to say, dark energy. Thus analogous to the exact irrational value of ordinary energy density of spacetime E(O)=(Φ5/2) mc2 we now have P (Casimir) = (Φ3/2)(ch/d2) where c is the speed of light, m is the mass, h is the Planck constant and d is the plate separation. In addition the new emerging geometry combined with the topology of E-infinity theory leads directly to identifying dark matter with the quasi matter of the ergosphere. As a direct consequence of this new insight E=mc2 which can be written as E = E (O) + E (D)?where the exact rational approximation is E (O)=mc2/22 is?the ordinary energy density of the cosmos and the exact rational approximation E (D)=mc2/(21/22) is the corresponding dark energy which could be subdivided once more albeit truly approximately into E(D)=mc2/(5/22)?+mc2/(16/22)??where 5 is the Kaluza Klein spacetime dimension, 16 are the bosonic extra dimensions of Heterotic superstrings and 5/22 □?22% is approximately the density of the dark matter-like energy of the ergosphere of the Kerr geometry. As for the actual design of our nano reactor, this is closely related to branching clusters of polymer, frequently called lattice animals. In other words we will have Casimir spheres instead of Casimir plates and these spheres will be basically nano particles modelling lattice animals. Here D=?4 will be regarded as spacetime dimensionality while D=6 of percolations are the compactified super string dimensions and D=8 is the dimension of a corresponding super space.

Efficacy evaluation of neuroendoscopy vs burr hole drainage in the treatment of chronic subdural hematoma:An observational study

BACKGROUND Chronic subdural hematoma(CSDH)is a common disease in neurosurgery.The traditional treatment methods include burr hole drainage,bone flap craniectomy and other surgical methods,and there are certain complications such as recurrence,pneumocephalus,infection and so on.With the promotion of neuroendoscopic technology,its treatment effect and advantages need to be further evaluated.AIM To study the clinical effect of endoscopic small-bone approach in CSDH.METHODS A total of 122 patients with CSDH admitted to our hospital from August 2018 to August 2021 were randomly divided into two groups using the digital table method:the neuroendoscopy group(n=61 cases)and the burr hole drainage group(n=61 cases).The clinical treatment effect of the two groups of patients with CSDH was compared.RESULTS At the early postoperative stage(1 d and 3 d),the proportion of 1/2 re-expansion of brain tissue in the hematoma cavity and the proportion of complete reexpansion was higher in the neuroendoscopy group than in the burr hole drainage group,and the difference between the two groups was statistically significant(P<0.05).The recurrence rate of hematoma in the neuroendoscopy group was lower than that in the burr hole drainage group,and the difference between the two groups was statistically significant(P<0.05).No intracranial hematoma,low cranial pressure,tension pneumocephalus or other complications occurred in the neuroendoscopy group.CONCLUSION The neuroendoscopic approach for the treatment of CSDH can clear the hematoma under direct vision and separate the mucosal lace-up.The surgical effect is apparent with few complications and definite curative effect,which is worthy of clinical promotion and application.

Time-like geodesic structure of a spherically symmetric black hole in the brane-world

Recently Malihe Heydari-Fard obtained a spherically symmetric exterior black hole solution in the brane-world scenario, which can be used to explain the galaxy rotation curves without postulating dark matter. By analysing the particle effective potential, we have investigated the time-like geodesic structure of the spherically symmetric black hole in the brane-world. We mainly take account of how the cosmological constant α and the stellar pressure β affect the time-like geodesic structure of the black hole. We find that the radial particle falls to the singularity from a finite distance or plunges into the singularity, depending on its initial conditions. But the non-radial time-like geodesic structure is more complex than the radial case. We find that the particle moves on the bound orbit or stable （unstable） circle orbit or plunges into the singularity, or reflects to infinity, depending on its energy and initial conditions. By comparing the particle effective potential curves for different values of the stellar pressureβ and the cosmological constant α, we find that the stellar pressure parameter β does not affect the time-like geodesic structure of the black hole, but the cosmological constant a has an impact on its time-like geodesic structure.

Gravitational Radiation of Binaries Coalescence into Intermediate Mass Black Holes

This paper discusses the gravitation waveforms of binaries coalescence into intermediate mass black holes(about 30 times of the solar mass).We focus on the non-spinning intermediate mass black hole located less than 100 Mpc from earth.By comparing two simulation waveforms(effective one body numerical relativity waveform(EOBNR),phenomenological waveform),we discuss the relationship between the effective distance and frequency;and through analyzing large amounts of data in event,we find that the phenomenological waveform is much smoother than EOBNR waveform,and has higher accuracy at the same effective distance.

Partial-SOI high voltage P-channel LDMOS with interface accumulation holes

A new partial SOI （silion-on-insulator） （PSOI） high voltage P-channel LDMOS （lateral double-diffused metal-oxide semiconductor） with an interface hole islands （HI） layer is proposed and its breakdown characteristics are investigated theoretically. A high concentration of charges accumulate on the interface, whose density changes with the negative drain voltage, which increase the electric field （Er） in the dielectric buried oxide layer （BOX） and modulate the electric field in drift region . This results in the enhancement of the breakdown voltage （BV）. The values of E1 and BV of an HI PSOI with a 2-~m thick SOI layer over a 1-~tm thick buried layer are 580V/~m and -582 V, respectively, compared with 81.5 V/p.m and -123 V of a conventional PSOI. Furthermore, the Si window also alleviates the self-heating effect （SHE）. Moreover, in comparison with the conventional device, the proposed device exhibits low on-resistance.

Screw dislocations interacting with two asymmetrical interfacial cracks emanating from an elliptical hole

The interaction between screw dislocations and two asymmetrical interfacial cracks emanating from an elliptic hole under loads at infinity is studied. The closed-form solution is derived for complex potentials. The stress intensity factor and the critical applied stress for the dislocation emission are also calculated. In the limiting cases, well-known results can be obtained from the present solutions. Moreover, new exact solutions for a screw dislocation interacting with some complicated cracks are derived. The results show that the shielding effect increases with the increase in the length of the other cracks and the minor semi axis, but decreases with the increase of dislocation azimuth. The repulsion acting on the dislocation from the other phase and the other crack extend in the horizontal direction, which makes the dislocation emission at the crack tip take place more easily, but the minor semi axis of the elliptical hole extending in the vertical direction makes it more difficult.

ANISOTROPIC EFFECTS OF QUASI－ISOTROPIC COMPOSITES（II）──APPLICATIONS AND MICRO－MECHANICAL ANALYSIS

Up to now the analysis on aisnotropic effects of quasi-isotropic composites to material structures has not been found in literatures. In the present paper the strength model for triaxial woven materials proposed in Part (I)[1]is applied to study the problems of an infintiely large plate of triaxial woven material containing either an either an elliptic hole or a crack. TO the elliptic hole problem the remote coritical loading as a function of the geometric parameters of woven materials is analysed and to the crack problem, the cracking orientation is examined. Finally the elasticity and strength models for a triaxial woven material proposed in Part (I)are verfied in terms of micromechanical analysis.