Ramp Region Research Articles

Comprehensive Facies Analysis and Depositional Environment Modeling of the Eocene Dammam Formation in Central to Southern Iraq

The Dammam Formation holds immense geological significance, as it spans across a substantial portion of southern Iraq, encompassing a vast area. This formation stands out as the primary aquifer source in the region. To gain a comprehensive understanding of its sedimentology, a comprehensive study was conducted using 310 samples extracted from various boreholes. These boreholes, including Kr-1, Kr-c.q., Nj-20, Ns-13, Ns-24, R-742, and Ru-509. The lithology of the Dammam Formation is limestone, dolomitic limestone, and dolomite rocks, which are also used as raw materials in the manufacture of cement. The microfacies analysis was carried out on Lower-Upper Eocene carbonate rocks along a center-south transect in Iraq. This analysis establishing larger benthic foraminifera enables to reconstruction of the paleoenvironmental model and to show the evolution of a platform along the depth gradient. The analysis revealed the presence of five primary microfacies within the Dammam Formation, each offering unique insights into its composition. These microfacies include Lime-mudstone, Wackestone, Packstone, Floatstone, and Rudstone, all of which contribute to a comprehensive understanding of the formation’s sedimentary makeup. Moreover, this in-depth examination uncovered an additional eight submicrofacies. The benthic foraminiferal assemblages within the Dammam Formation provide valuable insights into the progressive shifts along an ecological gradient, indicating a gradual transition from shallower, more protected (inner) shelf environments to deeper, more open (outer) shelf settings. Within the inner shelf, one can observe the prevalence of orbitolitids, alveolinids, and, to some extent, small miliolids, indicative of this relatively shallow and sheltered environment. Moving towards the inner ramp or shoal region, the foraminiferal composition is characterized by robust nummulitids, signifying the distinctive conditions of this particular zone. From a paleoenvironmental perspective, the Dammam Formation reflects deposition in a diverse range of environments, including peritidal inner ramp areas, lagoons, shoals, restricted-marine platforms, and open marine interior platforms. This variability underscores the complexity of the formation’s geological history and the diverse conditions under which its sediments accumulated over time.

Numerical investigation of turbulent flame-vortex interaction in premixed cavity stabilized flames

The combustion dynamics of a mixture of ethylene and air in a cavity flameholder are examined using high-resolution numerical simulations. The simulations are performed using both laminar and turbulent inflow boundary conditions to characterize the effects freestream turbulence on the flame-vortex interactions within the combustor. Experimental test results are utilized to validate the simulation's ability to capture the relevant flow and flame behavior. The turbulence intensity is shown to influence the structure of the flow field by creating a more dominant primary vortex within the combustor and decreasing the shear layer reattachment length. The integral length scales and energy spectra are calculated throughout the domain and show that the flow is driven by smaller turbulent eddies within the ramp region of the combustor. The flame-vortex interaction is further examined and revealed to cause an instability forming in the combustor under both laminar and turbulent conditions. The instability is confirmed by examining the pressure fluctuations within the combustor and it is demonstrated that the time scale of the pressure fluctuations corresponds to the frequency of the vortex shedding from the ramp wall.

Spectral form factor in the double-scaled SYK model

In this note we study the spectral form factor in the SYK model in large q limit at infinite temperature. We construct analytic solutions for the saddle point equations that describe the slope and the ramp regions of the spectral form factor time dependence. These saddle points are obtained by taking different approaches to the large q limit: the slope region is described by a replica-diagonal solution and the ramp region is described by a replica-nondiagonal solution. We find that the onset of the ramp behavior happens at the Thouless time of order q log q. We also evaluate the one-loop corrections to the slope and ramp solutions for late times, and study the transition from the slope to the ramp. We show this transition is accompanied by the breakdown of the perturbative 1/q expansion, and that the Thouless time is defined by the consistency of extrapolation of this expansion to late times.

Research on the lithofacies and paleogeography of the lower Cambrian Xiaoerbulake Formation in the northern Tarim Basin, northwestern China

Based on the study of cores, thin sections, and outcrops, the sedimentary facies of the lower Cambrian carbonate rocks in the northern Tarim Basin can be divided into four types: restricted platform, open platform, ramp, and basin. Based on the lithologic analysis of thin sections, two-dimensional seismic data interpretation, and an isopach map of the lower Cambrian Xiaoerbulake Formation in the study area, seven sedimentary facies of carbonate rocks were identified, including inner platform depression, shoal, intershoal sea, platform margin, gypsum salt lake, ramp, and basin. The depositional model of the lower Cambrian Xiaoerbulake Formation in the northern Tarim Basin is constructed based on this integrated research. The topset, foreset, and bottomset of oblique progradational reflections are interpreted as the platform margin beach, ramp, and basin environments, respectively. The thicker area with micritic dolomite as the dominant lithology is interpreted as a platform depression. The low-amplitude hummocky reflections are interpreted as shoals that consist of a variety of granular dolomite and algal dolomite. The thinner uplifted area with gypsum and dolomite present in cores is interpreted as a restricted platform with a gypsiferous dolomite tidal flat or lake environment. Well LT1, which was drilled recently in the platform margin and ramp region, as indicated by seismic progradational clinoform reflections, has produced high yields of oil and gas. Supported by the above research results, the map of the lithofacies and paleogeography of the Xiaoerbulake Formation in the northern Tarim Basin was recompiled.

Effects of Wall Ventilation on the Shock-wave/Viscous-Layer Interactions in a Mach 2.2 Intake

In order to achieve proficient combustion with the present technologies, the flow through an aircraft intake operating at supersonic and hypersonic Mach numbers must be decelerated to a low-subsonic level before entering the combustion chamber. High-speed intakes are generally designed to act as a flow compressor even in the absence of mechanical compressors. The reduction in flow velocity is essentially achieved by generating a series of oblique as well as normal shock waves in the external ramp region and also in the internal isolator region of the intake. Thus, these intakes are also referred to as mixed-compression intakes. Nevertheless, the benefits of shock-generated compression do not arise independently but with enormous losses because of the shockwave and boundary layer interactions (SBLIs). These interactions should be manipulated to minimize or alleviate the losses. In the present investigation a wall ventilation using a new cavity configuration (having a cross-section similar to a truncated rectangle with the top wall covered by a thin perforated surface is deployed underneath the cowl-shock impinging point of the Mach 2.2 mixed-compression intake. The intake is tested for four different contraction ratios of 1.16, 1.19, 1.22, and 1.25, with emphasis on the effect of porosity, which is varied at 10.6%, 15.7%, 18.8%, and 22.5%. The introduction of porosity on the surface covering the cavity has been proved to be beneficial in decreasing the wall static pressure substantially as compared to the plain intake. A maximum of approximately 24.2% in the reduction in pressure at the upstream proximal location of 0.48 L is achieved in the case of the wall-ventilated intake with 18.8% porosity, at the contraction ratio of 1.19. The Schlieren density field images confirm the efficacy of the 18.8% ventilation in stretching the shock trains and in decreasing the separation length. At the contraction ratios of 1.19, 1.22, and 1.25 (‘dual-mode’ contraction ratios), the controlled intakes with higher porosity reduce the pressure gradients across the shockwaves and thereby yields an ‘intake-start’ condition. However, for the uncontrolled intake, the ‘unstart’ condition emerges due to the formation of a normal shock at the cowl lip. Additionally, the cowl shock in the ‘unstart’ intake is shifted upstream because of higher downstream pressure.

Ediacaran ramp depositional model of the Tamengo Formation, Brazil

The Tamengo Formation corresponds to one of the most complete records of Ediacaran carbonate deposits in South America that contains Cloudina and Corumbella calcified exoskeletons macroscopic fossils. With the objective of characterizing its paleoenvironment, a total of ten sedimentary facies indicative of a carbonate platform were identified. In the outer ramp region there are massive mudstones, massive marl to claystones, and shales. In the mid-ramp there are facies that are storm-dominated with swaley/hummocky cross-stratified grainstone, tangential cross-bedding grainstone, massive bioclastic grainstone and massive marl to claystone. Lastly, in the inner ramp portion there are massive intraclastic grainstone, massive intraclastic rudstone, massive oolitic grainstone and laminate mudstone/shale rhythmite, and microbial textures are present at the base of the rhythmites, indicative of a back-ramp environment. Faciology data indicate that the Cloudinas inhabited a protected environment between oolitic bars in the inner ramp and back-ramp. These organisms were periodically transported and reworked by waves generated by storms in the mid-ramp and outer ramp zones. The positive values for δ13C in carbonates (1,5 to 5,4‰) and δ15N (between 3,5 and 4,5‰) of deposits with Cloudina indicate a marine paleoenvironment with shallow, hot, and oxygenated waters with a high productivity of organic matter. In this context, the facies analyses and stratigraphy, aided by C, O, and N isotopes from the Tamengo Formation in outcrops from the Corumbá regions in the southwest of Brazil allows for the reconstruction of an Ediacaran carbonate ramp and inferences about the habitat of Cloudina, thus increasing understanding of this important chapter of Earth history.

Helicopter Fuselage Model Drag Reduction by Active Flow Control Systems

A comprehensive experimental investigation of a helicopter blunt fuselage model was carried out to evaluate the effectiveness of active flow control (AFC) systems in reducing parasite fuselage drag. The main objective was to demonstrate the capability of different active technologies to decrease fuselage drag by alleviating the flow separation in the loading ramp region of large transport helicopters. The work was performed on a simplified blunt fuselage at model scale. Two different flow control actuators were considered for evaluation: steady blowing and unsteady blowing (i. e., pulsed jets). Laboratory tests of each individual actuator were performed to assess their performance and properties. The fuselage model was investigated with and without the AFC systems located along the loading ramp edges. Significant drag reductions were achieved for a wide range of fuselage angles of attack and sideslip angles without negatively affecting other aerodynamic characteristics.

Mesoscopic, magnetic and petrofabric study of the High Himalayan gneisses and leucogranite along oblique and frontal ramps of the Vaikrita Thrust in Satluj and Bhagirathi valleys: Thrust locking and superposed folding

Field, microstructural and anisotropy of magnetic susceptibility (AMS) studies were performed along the oblique thrust ramp of the Satluj river valley and frontal thrust ramp of the Bhagirathi river valley. The presence of asymmetric and sheath folds indicates intense shearing near the thrust. The simple shear gradually decreases with an increase in distance from the thrust and pure shear with upright folds becomes prominent. The AMS studies suggest slightly higher pure shear in the frontal ramp region as compared to the oblique ramp region where oblique slip was predominant. The sense of shear criteria and orientation of superposed folds indicate locking of the thrust. Normal faults are the youngest structure.

Analysis of Ion Motion and Diffusion Confinement in Inverted Drift Tubes and Trapped Ion Mobility Spectrometry Devices.

Ion motion in trapped ion mobility spectrometers (TIMS) and inverted drift tubes (IDT) has been investigated. The two-dimensional (2D) axisymmetric analytical solution to the Nernst-Planck equation for constant gas flows and opposed linearly increasing fields is presented for the first time and is used to study the dynamics of ion distributions in the ramp region. It is shown that axial diffusion confinement is possible and that broad packets of ions injected initially into the system can be contracted. This comes at the expense of the generation of a residual radial field that pushes the ions outward. This residual electric field is of significant importance as it hampers sensitivity and resolution when parabolic velocity profiles form. When radio frequency (RF) is employed at low pressures, this radial field affects the stability of ions inside the mobility cell. Trajectories and frequencies for stable motion are determined through the study of Mathieu's equation. Finally, effective resolutions for the ramp and plateau regions of the TIMS instrument are provided. While resolution depends on the inverse of the square root of mobility, when proper parameters are used, resolutions in the thousands can be achieved theoretically for modest distances and large mobilities.

Onset of random matrix behavior in scrambling systems

The fine grained energy spectrum of quantum chaotic systems is widely believed to be described by random matrix statistics. A basic scale in such a system is the energy range over which this behavior persists. We define the corresponding time scale by the time at which the linearly growing ramp region in the spectral form factor begins. We call this time tramp. The purpose of this paper is to study this scale in many-body quantum systems that display strong chaos, sometimes called scrambling systems. We focus on randomly coupled qubit systems, both local and k-local (all-to-all interactions) and the Sachdev-Ye-Kitaev (SYK) model. Using numerical results, analytic estimates for random quantum circuits, and a heuristic analysis of Hamiltonian systems we find the following results. For geometrically local systems with a conservation law we find tramp is determined by the diffusion time across the system, order N2 for a 1D chain of N qubits. This is analogous to the behavior found for local one-body chaotic systems. For a k-local system like SYK the time is order log N but with a different prefactor and a different mechanism than the scrambling time. In the absence of any conservation laws, as in a generic random quantum circuit, we find tramp ∼ log N, independent of connectivity.

Effect of Operating Conditions on the Elastohydrodynamic Performance of Foil Thrust Bearings for Supercritical CO2 Cycles

In this paper, a quasi-three-dimensional fluid–structure model using computational fluid dynamics for the fluid phase is presented to study the elastohydrodynamic performance of foil thrust bearings for supercritical CO2 cycles. For the simulation of the gas flows within the thin gap, the computational fluid dynamics solver Eilmer is extended, and a new solver is developed to simulate the bump and top foil within foil thrust bearings. These two solvers are linked using a coupling algorithm that maps pressure and deflection at the fluid structure interface. Results are presented for ambient CO2 conditions varying between 0.1 and 4.0 MPa and 300 and 400 K. It is found that the centrifugal inertia force can play a significant impact on the performance of foil thrust bearings with the highly dense CO2 and that the centrifugal inertia forces create unusual radial velocity profiles. In the ramp region of the foil thrust bearings, they generate an additional inflow close to the rotor inner edge, resulting in a higher peak pressure. Contrary to the flat region, the inertia force creates a rapid mass loss through the bearing outer edge, which reduces pressure in this region. This different flow fields alter bearing performance compared to conventional air foil bearings. In addition, the effect of turbulence in load capacity and torque is investigated. This study provides new insight into the flow physics within foil bearings operating with dense gases and for the selection of optimal operating condition to suit CO2 foil bearings.

On Electron Adiabaticity in Collisionless Shocks

Collisionless shocks are considered as one of the most efficient phenomena for the electron acceleration in space and astrophysical plasmas, yet the detailed acceleration process and heating mechanism remain unsolved. Various acceleration and heating mechanisms have so far been proposed and discussed to explain the spacecraft measurements in situ at Earth’s bow shock, involving the large-scale electromagnetic fields, plasma turbulence, and wave-particle interactions. A key element of the acceleration and heatingmechanisms is the spatial scale of the shock transition with respect to the gyro-radius of the electrons [1]. In the simplest picture, since the shock transition occurs on a spatial scale of ion gyro-radius, the electrons behave as magnetized at the shock transition. The cross-shock potential (electrostatic potential drop across the shock transition) plays two distinct roles in electron dynamics [2]. First, the cross-shock potential reduces a certain amount of the upstream flow kinetic energy (mostly carried by the ions due to their mass); Second, the kinetic energy is used to heat the electrons (DC heating). On the other hand, the electrons can also be scattered (or demagnetized) by high-amplitude, randomly-oscillating electromagnetic fields such as turbulence or strong inhomogeneities (AC heating). Space turbulence can potentially scatter the electrons randomly leaving upstream or downstream of the shock ramp region. For a quasiperpendicular shock, the electrons become scattered in a non-adiabatic sense perpendicular to the mean magnetic field (Figure 1). In this paper, the adiabaticity in collisionless shocks is addressed to the studies based on particlein-cell-simulation (PIC). Two important parameters enter a PIC simulation carried out for the study of a collisionless shock: the mass ratio mp/me between ions and electrons and the ratio of the electron plasma frequency to gyrofrequency ωpe/ce, see e.g., [3]. Due to the computational limitations, the usage of the realistic values for the both parameters is not yet possible. The common way to overcome this problem is to find a compromise for the two parameters that can mostly optimize the purpose of the study. The impact of using low frequency ratio of the electron plasma frequency to gyrofrequency in numerical simulations has been discussed in Krasnoselskikh et al. [4]: the electric field is considerably overestimated than it should be for a comparison with the Earth bow shock. Here, I address the question, “What is the consequence of using a smaller frequency ratio upon the adiabatic motion of the electrons”?

An Equilibrium Constitutive Model of Anisotropic Cartilage Damage to Elucidate Mechanisms of Damage Initiation and Progression.

Traumatic injuries and gradual wear-and-tear of articular cartilage (AC) that can lead to osteoarthritis (OA) have been hypothesized to result from tissue damage to AC. In this study, a previous equilibrium constitutive model of AC was extended to a constitutive damage articular cartilage (CDAC) model. In particular, anisotropic collagen (COL) fibril damage and isotropic glycosaminoglycan (GAG) damage were considered in a 3D formulation. In the CDAC model, time-dependent effects, such as viscoelasticity and poroelasticity, were neglected, and thus all results represent the equilibrium response after all time-dependent effects have dissipated. The resulting CDAC model was implemented in two different finite-element models. The first simulated uniaxial tensile loading to failure, while the second simulated spherical indentation with a rigid indenter displaced into a bilayer AC sample. Uniaxial tension to failure simulations were performed for three COL fibril Lagrangian failure strain (i.e., the maximum elastic COL fibril strain) values of 15%, 30%, and 45%, while spherical indentation simulations were performed with a COL fibril Lagrangian failure strain of 15%. GAG damage parameters were held constant for all simulations. Our results indicated that the equilibrium postyield tensile response of AC and the macroscopic tissue failure strain are highly dependent on COL fibril Lagrangian failure strain. The uniaxial tensile response consisted of an initial nonlinear ramp region due to the recruitment of intact fibrils followed by a rapid decrease in tissue stress at initial COL fibril failure, as a result of COL fibril damage which continued until ultimate tissue failure. In the spherical indentation simulation, damage to both the COL fibril and GAG constituents was located only in the superficial zone (SZ) and near the articular surface with tissue thickening following unloading. Spherical indentation simulation results are in agreement with published experimental observations. Our results indicate that the proposed CDAC model is capable of simulating both initial small magnitude damage as well as complete failure of AC tissue. The results of this study may help to elucidate the mechanisms of AC tissue damage, which initiate and propagate OA.

Variable Transpiration Cooling Effectiveness in Laminar and Turbulent Flows for Hypersonic Vehicles

Reusable thermal-protection systems with active cooling, such as transpiration, are among the promising technologies for thermal management of hypersonic vehicles designed as practical, long-range transportation systems. This paper numerically investigates the effectiveness and efficiency of a variable-velocity transpiration technology for fully laminar and fully turbulent hypersonic flows over a two-dimensional blunt leading-edge geometry. For both flow types, variable transpiration based on a sawtooth velocity distribution is compared to a uniform-velocity transpiration approach. An equal amount of coolant has been imposed to compare the cooling effectiveness between two strategies. The results numerically demonstrate the significant reduction in stagnation-point heating and coolant mass savings achievable with the variable-transpiration strategy, which is observed both in laminar and turbulent flows. The transpiration cooling efficiency is shown to be higher in laminar flow compared to turbulent flow downstream of the leading edge (ramp region). In such regions, for turbulent flows, the amount of total coolant must be increased by a factor of 2 to match the cooling efficiency in laminar flows. The thermal response of a porous thermal-protection-system material is investigated in laminar and turbulent flows with variable transpiration to gain important insight about the matrix and coolant behavior in response to external flow.

On the fine structure of dipolarization fronts

AbstractMeasurements from the closely spaced Cluster spacecraft are used to study the structure of the magnetic and electric fields within the magnetic ramp of dipolarization fronts (DF) observed close to the neutral sheet and the midnight meridian (YGSM<3RE). The spacecraft separation was small enough (<300 km) to treat the magnetic ramp of the DF front as a planar structure as indicated from variance analysis. The finite value of the magnetic field along the minimum variance direction for the events studied indicates that the dipolarization front structure was distinct from a tangential discontinuity. In addition to the main increase of the magnetic field in the maximum variance component, strong oscillations were observed in the intermediate component. The presence of this oscillatory structure results in an expansion of the region in which a change of magnetic pressure occurs, the size of which is typically an ion Larmor radius or greater. This widening is important in maintaining the pressure balance at the edge of the DF. This phenomenon resembles observations of intense current sheets in the magnetotail and also laboratory experiments of current sheet formation, in which a similar widening of the ramp region has been observed. In this paper we argue against the idea that an electron temperature anisotropy, resulting in electron curvature currents, can explain the formation of the oscillatory structures observed at DFs. These oscillations can be explained as eigenmode waves of the plasma that propagate away from the disturbance (DF) that is moving at subsonic speeds. Oscillations observed within the magnetic ramp indicate field‐aligned currents that are expected to be associated with DF.

The ballistic transport instability in Saturn's rings - III. Numerical simulations

Saturn's inner B-ring and its C-ring support wavetrains of contrasting amplitudes but with similar length scales, 100-1000 km. In addition, the inner B-ring is punctuated by two intriguing `flat' regions between radii 93,000 km and 98,000 km in which the waves die out, whereas the C-ring waves coexist with a forest of plateaus, narrow ringlets, and gaps. In both regions the waves are probably generated by a large-scale linear instability whose origin lies in the meteoritic bombardment of the rings: the ballistic transport instability. In this paper, the third in a series, we numerically simulate the long-term nonlinear evolution of this instability in a convenient local model. Our C-ring simulations confirm that the unstable system forms low-amplitude wavetrains possessing a preferred band of wavelengths. B-ring simulations, on the other hand, exhibit localised nonlinear wave `packets' separated by linearly stable flat zones. Wave packets travel slowly while spreading in time, a result that suggests the observed flat regions in Saturn's B-ring are shrinking. Finally, we present exploratory runs of the inner B-ring edge which reproduce earlier numerical results: ballistic transport can maintain the sharpness of a spreading edge while building a `ramp' structure at its base. Moreover, the ballistic transport instability can afflict the ramp region, but only in low-viscosity runs.

Comment on “Electron demagnetization and heating in quasi‐perpendicular shocks” by Mozer and Sundkvist

In their paper, Mozer and Sundkvist (2013) present important observations of large‐amplitude high‐frequency electric field fluctuations in the vicinity of the ramp region of the Earth's bow shock. In common with other recent work, they emphasize the role of electron scattering by such fluctuations in the problem of electron heating at collisionless shocks, relegating the DC fields to providing a reservoir of energy which can be tapped apparently to whatever degree is required. While the historical approach of attributing the zeroth‐order electron heating to adiabatic motion in those DC fields has always required some unspecified scattering process, key elements of those DC processes have been lost or misinterpreted. In particular, particle motion parallel and perpendicular to the magnetic field are coupled to one another. More importantly, an O(1/2) fraction of the electron population traverses the shock from downstream to upstream or are trapped downstream. Thus, the concept of irreversible heating proceeding from the solar wind through the shock into the magnetosheath, implicit in Mozer and Sundkvist (2013), needs to be reconsidered. A highly simplified calculation illustrates these points.

Tunneling spectra and superconducting gaps observed by scanning tunneling microscopy near the grain boundaries of FeSe0.3Te0.7 films

We used scanning tunneling microscopy (STM) to study the tunneling spectra of FeSe0.3Te0.7 films with two orientations of the ab-planes and a connection ramp between them. We discovered that by pulsed laser deposition (PLD) method, the a- and b-axis of the FeSe0.3Te0.7 film deposited on an Ar-ion-milled magnesium oxide (MgO) substrate were rotated 45° with respect to those of MgO, whereas the a- and b-axis of the film grown on a pristine MgO substrate were parallel to those of MgO. With photolithography and this technique, we can prepare FeSe0.3Te0.7 films with two orientations on the same MgO substrate so that the connection between them forms a ramp at an angle of about 25° to the substrate plane. In the planar region, for either the 0° or 45° orientation, we observed tunneling spectra with a superconducting gap of about 5meV and 1.78meV, respectively. However, a much larger gap at about 18meV was observed in the ramp region. Furthermore, we observed a small zero-bias conductance peak (ZBCP) inside the large gap at T=4.3K. The ZBCP becomes smaller with increasing temperature and disappeared at temperature above 7K.

Application of Inversion after Limestone Hollow-Out in Pearl River Mouth Basin

The target layer of study area belongs to delta front and shallow shelf deposition, and the sedimentary formation is sandstone and mudstone thin interbed, the limy developed in sand layer. To make the inversion data reflect the characteristics of reservoir accurately, the methods of limy separation analysis by drilling and forward modeling have been used in this paper, and removed the limy from seismic data according to the characteristics of wave impedance（limestone hollow-out）. According to the research of limestone hollow-out Inversion, delta front sand bodies developed in the J2 formation of H district, and the J2 formation of H district where it is in the west of the study area, a gravity flow channel in the center, shallow shelf sand ridge sand bodies mainly developed in the eastern; delta front sand bodies developed in the J1 formation of HD district, which includes underwater branch channel sand body. A number of lithologic traps have been found and optimized by the research of Retrieval data near the large fault and ramp region, and also have achieved the intended purpose. This inversion method is a kind of reservoir prediction method based on seismic, geological and logging, which added in forward modeling techniques, and is an extension of Model seismic inversion method, and also Provided a new approach for reservoir prediction of the special lithological developed zone.

Ion Trapping for Ion Mobility Spectrometry Measurements in a Cyclical Drift Tube

A new ion trapping technique, involving the accumulation of ions in a cyclical drift tube, as a means of enhancing ion signals for scanning ion cyclotron mobility measurements has been modeled by computational simulations and demonstrated experimentally. In this approach, multiple packets of ions are periodically released from a source region into the on ramp region of the cyclical drift tube and these pulses are accumulated prior to initiation of the mobility measurements. Using this ion trapping approach, it was possible to examine ions that traversed between 1.83 and 182.86 m (from 1 to 100 cycles). Overall, we observe that instrumental resolving power improves with increasing cycle numbers; at 100 cycles, a resolving power in excess of 1000 can be achieved. The utility of this method as a means of distinguishing between analytes is demonstrated by examining the well-characterized model peptides substance P, angiotensin II, and bradykinin.