Lateral Component Research Articles

HISTOLOGICAL EVALUATION OF SUBCHONDRAL BONE DRILLING FOR PREIMPLANTATION PREPARATION OF OSTEOCHONDRAL ALLOGRAFTS

Despite the growing success of OCA transplantation in treating large articular cartilage lesions in multiple joints, revisions and failures still occur. While preimplantation subchondral drilling is intended to directly decrease allograft bioburden and has been associated with significant improvements in outcomes after OCA transplantation, the effects of size, number, and spacing of subchondral bone drill sites have not been fully evaluated. This study aimed to investigate the effects of drill size with or without pulse-lavage of OCA subchondral bone by quantifying remnant marrow elements using histomorphometry.With IRB and ACUC approvals, human and canine OCAs were acquired for research purposes. Portions of human tibial plateau OCAs acquired from AATB-certified tissue banks that would otherwise be discarded were recovered and sectioned into lateral and medial hemiplateaus (n=2 each) with a thickness of 7 mm. Canine femoral condyles and tibial plateaus were split into lateral and medial components with a thickness of 7 mm (n=8). Using our clinical preimplantation preparation protocol, holes were drilled into the subchondral bone of each condyle and hemiplateau OCA using either 1.6 mm OD or 3.2 mm OD drill bits from the cut surface to the cortical subchondral bone plate. One femoral condyle and one hemiplateau per drill bit size were pulse-lavaged while the corresponding OCAs were not. The mean total %-fill remaining marrow elements for each treatment group was calculated.Little to no quantifiable bone marrow element retention was noted to remain within the subchondral bone of human or canine OCA specimens after subchondral drilling of allograft bone with either drill bit size evaluated and with or without pulse-lavage. The %-fill was consistent across zones, ranging from 1-5%.This project was designed to provide a preliminary histologic evaluation of the effects of drill size on OCA preimplantation preparation efficacy based on amount of remaining bone marrow elements in human and canine femoral condyle and tibial plateau specimens. Based on these initial findings, choice of drill bit size for OCA subchondral drilling may need to be based on the associated biomechanical effects rather than effects on donor bone marrow element removal.

Retrofitting Vertical Slot Fish Pass with Brush Blocks: Hydraulics Performance

The mean and turbulent flow characteristics of a vertical slot fish pass, with and without brush blocks, were investigated at the Cataloluk Small Hydropower Plant on the Tekir River, located in the Ceyhan River Basin of Turkey. Within the scope of the project, three-dimensional velocity measurements were performed at different hydraulic conditions. The prototype flow measurements showed that by placing brush blocks and the substrate in the vertical-slot pool: (i) the maximum velocity observed downstream of the slot was reduced by 39%; (ii) the maximum lateral component of the Reynolds shear stress observed in the slot region was reduced by a factor of 3; and (iii) the spatially averaged resultant velocity was reduced by 20%. With brush blocks, the turbulent jet region was reduced and recirculation regions disappeared. Furthermore, the spatially-averaged lateral component of the Reynolds shear stress was 3.3 times higher than the spatially-averaged streamwise component of the Reynolds shear stress because of the lateral velocity gradient and mixing in the pool. The present findings will contribute to potential improvements in the non and less efficiently-functioning vertical slot fish pass and other fish pass types by adding brush blocks.

Dynamic characteristics analysis of gear transmission and its support bearings of high-speed train on the curve

The gear transmission in high-speed trains is crucial for transmitting the traction torque. Its dynamic characteristics impact the system's reliability and safety. Additionally, the gear transmission and its support bearings can be affected by wheel-rail interactions, particularly on curves with larger centrifugal forces. To address this, a spatial vehicle-track coupled dynamics model that considers the complete power transmission path and mechanical structure of the gear transmission is proposed. The model considers factors such as time-varying mesh stiffness, dynamic transmission error (DTE), time-varying support stiffness, and internal interactions of the gearcase bearing. Results indicate that when a high-speed train passes through a curve, the derailment coefficient and lateral force of the wheelset are less on the right curve due to the lateral component of the mesh force, but the opposite occurs on the left curve. The centrifugal effect affects the contributions of the lateral and vertical motions of the gear pair, which are balanced by the torsional motions of the components in the power transmission path. Additionally, the internal interactions between the rolling elements and races are intensified due to track irregularity and gear engagement, but the centrifugal effect of the pinion can be ignored.

Early clinical application of Mako robot-assisted total knee arthroplasty in knee osteoarthritis

To investigate the early efficacy of Mako robot-assisted total knee arthroplasty (TKA) in the treatment of knee osteoarthritis (KOA) and summarize the initial application experience. Retrospective analysis of 73 patients with KOA treated with Mako robot-assisted TKA from June 2021 to December 2021. There were 16 males and 57 females, aged from 54 to 81 years old with an average of (67.8±6.6) years old. The hip knee and ankle angle (HKA), lateral distal femoral angle (LDFA), medial proximal tibial angle (MPTA), lateral femoral component angle (LFCA) and lateral tibial component angle (LTCA) were recorded and analyzed. WOMAC score and KSS were used to compare the functional recovery of patients preoperatively, 3 and 6 months postoperatively. All the 73 patients were successfully treated without serious complications such as vascular and nerve injury, and all the incisions healed well at stageⅠwithout infection. The patients were followed up from 4 to 11 months with an average of (7.0±2.7) months, and the satisfaction rate of the last follow-up was 90.41% (66/73). WOMAC scores were (23.1±5.4) at 3 months and (14.8±4.1) at 6 months postoperatively. KSS clinical scores were ( 76.1±4.0) at 3 months and (82.1±3.7) at 6 months postoperatively;KSS functional scores were (74.3±3.1) at 3 months and (78.6±2.1) at 6 months after operation. Postoperative imaging showed good position of the prosthesis, HKA angle was (178.5±2.1)°, LDFA was (91.2±1.8)°, MPTA was(89.9±1.5) °, LFCA was (7.6±3.1)°, LTCA was (88.2±1.1)°. The mechanical axis within ±3° in sixty cases(82.2%), and the mechanical axis within ±6° in all the patients. Mako robot-assisted TKA is a safe and effective surgery in the treatment of knee osteoarthritis, which exhibited good efficacy in the correction of lower limb alignment, soft tissue balance and improvement of knee function. The long-term efficacy needs further follow-up observation.

The Horizontal Mode Natural Frequency of a Floating Pile in Layered Soil: Full-Scale Field Test Vs Mathematical Models

Pile supported structures can be subjected to a variety of man-made and naturally occurring dynamic loads. Dynamic loads such as those from rotating machinery include a considerable lateral component. The natural frequency of a pile in the horizontal mode becomes a key parameter in the design of dynamically sensitive equipment foundations. It is not uncommon for structural engineers to estimate the natural frequency of piles using quick linear methods using available soil investigation data before advanced laboratory tests on soil samples can be performed to calibrate nonlinear numerical models. This paper presents results from free and forced vibration tests on a full-scale single pile, designed for a high-speed compressor unit, in Hazira, India. Two different fast mathematical models, one following the Beam on Dynamic Winkler Foundation (BDWF) method, and another involving an FEM–BEM based numerical method were used in predictions against experimental results. The BDWF method was found to produce a preliminary estimate of pile stiffness at low strain levels. However, the selection of soil stiffness and damping models are crucial for the accuracy of BDWF models. It was found that the FEM–BEM model was able to simulate the nonlinear pile response with a moderate overestimation of vibration amplitudes.

Anatomical location of the surgically identifiable bladder branch of the inferior hypogastric plexus for nerve-sparing radical hysterectomy

ObjectiveWe aimed to demonstrate the entire structure of the inferior hypogastric plexus in the female pelvis focusing on surgically identifiable nerve bundles to the urinary bladder. MethodsSurgical videos of transabdominal nerve-sparing radical hysterectomy for 10 patients with cervical cancer at International Federation of Gynecology and Obstetrics (FIGO 2009) stage IB1–IIB were retrospectively analyzed. The paracervical tissue dorsal to the ureter was separated into the lateral component (dorsal layer of the vesicouterine ligament) and medial component (paracolpium) using Okabayashi’s technique. Any bundle-like structures in the paracervical area were isolated and divided using cold scissors, and each cut edge was inspected to determine whether the bundle was a blood vessel or a nerve. ResultsIn all cases, the surgically identifiable nerve bundle of the bladder branch was identified on the rectovaginal ligament running parallel and dorsal to the vaginal vein of the paracolpium. The bladder branch was revealed only after complete division of the vesical veins in the dorsal layer of the vesicouterine ligament where no definitive nerve bundles were observed. The bladder branch was derived laterally from the pelvic splanchnic nerve and medially from the inferior hypogastric plexus. ConclusionsThe surgical identification of the nerve bundle of the bladder branch is essential for a safe and secure nerve-sparing radical hysterectomy. The preservation of the surgically identifiable bladder branch from the pelvic splanchnic nerve as well as from the inferior hypogastric plexus can provide satisfactory postoperative voiding function.

Late Quaternary slip rate of the Fengmenkou-Wuzhiling fault at the southern margin of North China block (S-NCB)

The regional crustal slipping behaviour within the interaction zone of the North China and Qinling blocks reveals the pattern of extensional grabens merging with strike-slip faults and establishes the contribution of these faults to the regional basin generation. In this study, we aimed to assess the active slipping at the Laojing Gou site along the Fengmenkou-Wuzhiling fault (FMK-WZLF), one of the main active faults at the southern margin of North China block (S-NCB), by setting a three-dimensional measurement of the offset in buried paleochannels. Mapping, trenching, and age constraints of the geomorphic and stratigraphy units illustrate three offset paleo-fluvial surfaces since the Late Pleistocene, named S1, S2, and S3, along the fault strike direction. Beneath the surface, the structure of isolated confined paleo-channels C1 and C3 was exposed on the stratigraphy profile, and they were active during 130–75 ka and 2.8–3.0 ka, respectively. We presented a set of adapted scripts for three-dimensional measurements to calculate the lateral and normal tectonic components. The left lateral slip rate for the FMK-WZLF was estimated to be 0.25–0.45 mm/a, and the long-term oblique slipping behaviour generated the scarps in a dip of 70° ± 5° across the fault plane. The oblique slip of the FMK-WZLF, together with the regional E-W and SW-NE striking normal fault system, shapes the northeastward flowing Yiluo river and the southeastward flowing Huai river at S-NCB.

Unravelling the impact of geological heterogeneities in the reservoir management. An integrated study of the deep-water Akpo field (Niger delta)

Geological and seismic data have been integrated to describe the impact of structural and sedimentological heterogeneities on fluid dynamics for one of the reservoirs (Reservoir X) of the Akpo field (deep offshore of Niger Delta). Akpo is a sinuous 4-way anticline formed because of strong deformation occurring within the over pressurized shales of the Akata Formation. Weak deformation may have started since 9 Ma; however, most of the strain associated with shortening was accumulated between ca 7 Ma and ca 3 Ma. The cumulative shortening has been estimated in the order of 4% (ca 400 m). From 3 Ma (during the latest stages of growth of the Akpo anticline) up to Present-day, the residual strain was taken up by oblique (right lateral strike-slip component) extensional faults, between 2 km and ca 15 km in length, organized into two main trends: N-dipping, ENE-WSW to NE-SW striking faults, and NNW-SSE striking faults mainly dipping to the east. These faults are segmented and have a maximum throw in the order of 70 m. Based on the architectural elements identified in this work, the Reservoir X of the Akpo field has been subdivided into three main intervals: a basal lobe (Interval 1a) and a related channel (Interval 1 b); two intermediate generations of meandering channels (Interval 2a and 2 b); and an upper and strongly erosional constructive channel (Interval 3). The 4D signal has been integrated to better understand the complex fluid flow within Reservoir X in time and space. The extensional faults play a role in baffling mainly in the central part of the field, where across-fault flow is likely to occur in correspondence with the spill points. Facies distribution and the nature of the contact between various reservoir intervals are also important because vertical and lateral communication between sand bodies can be complex. Levees or mud barriers can inhibit flow, impacting both efficiency of support between injectors and producers. On the other hand, sand-to-sand communication due to the strong erosional character of the contacts enhances dynamic connectivity between sands belonging to different reservoir intervals. As an example, even if sands belonging to Interval 3 totally erode (i.e. dynamically isolate) those of Interval 2 in the southern part of the field, in the northern sector the two reservoir intervals are in (vertical) communication as suggested by the 4D signal. A key result of this integrated work is that of documenting in detail the modes in which faults and sedimentary features impact fluid flow within and across reservoir intervals in a deep-water environment.

Lateral recoil optical forces on nanoparticles near nonreciprocal surfaces

We investigate lateral recoil forces exerted on nanoparticles located near plasmonic platforms with in-plane nonreciprocal response. To this purpose, we first develop a comprehensive theoretical framework based on the Lorentz force within the Rayleigh approximation combined with nonreciprocal Green's functions and then derive approximate analytical expressions to model lateral recoil forces, demonstrating their explicit dependence on the dispersion relation of the system and unveiling the mechanisms that govern them. In particular, a dominant lateral recoil force component appears due to the momentum imbalance of nonreciprocal surface plasmons supported by the platform. This force can be orders of magnitude larger than other recoil force components, acts only along or against the direction of the external bias, and is quasi-independent of the direction, polarization, and wavelength of the incident plane wave. Lateral recoil forces are explored using drift-biased graphene metasurfaces, a platform that is also proposed to sort nanoparticles as a function of their size. Nonreciprocal plasmonic systems may enable new venues to trap, bind, and manipulate nanoparticles and to alleviate some of the challenges of conventional optical tweezers.

Flow State at Impeller Inlet: Optimization of Conical Frustum Section of Elbow Inlet Conduit in Large Low-Lift Pump Station

Abstract In large low-lift pump stations, the pump assembly comprises an inlet conduit, a pump, and an outlet conduit. A short conical frustum section that connects the elbow section with the impeller inlet directly affects the impeller inflow state, thereby influencing the overall performance. Therefore, investigating the conical frustum section contributes to studying the effect of inflow states on the performances of pump assemblies and similar pumping systems. To improve the pump assembly efficiency, three parameters of the conical frustum section, i.e., the contraction angle, height, and centerline inclination angle, are investigated and optimized via univariate and multivariate analyses. The flow field and external characteristics of the pump assembly are investigated via computational fluid dynamics simulation with a constant head. Furthermore, a comprehensive analysis and discussion of the performance improvement mechanisms are presented. The results indicate that the axial velocity distribution at the impeller inlet conforming to the cascade high-efficiency characteristics will achieve a better pump performance compared with a uniform distribution. The pump efficiency distribution can be predicted and visualized based on the cascade efficiency characteristics and the flow state at the impeller inlet using a machine learning method. In addition, the directions and distribution of the lateral and axial components of the inflow velocities have great impacts on the circulation distribution. A sensible circulation distribution at the guide vane outlet can suppress the entropy production and reduce hydraulic loss of the outlet conduit. In this case, a significant increase in the pump assembly efficiency is obtained.

3-D Nonlinear Guidance Law for Target Circumnavigation

In this letter, we address the problem of circumnavigating a stationary target using a single vehicle. Unlike most existing results wherein the target is encircled in a two-dimensional plane, we focus on devising a guidance strategy that enables a vehicle to encircle a target in a three-dimensional space using the relative information between the vehicle and the target. In particular, we assume that the vehicle has lateral acceleration capabilities only and that the radial acceleration is unavailable, thereby making the proposed design favorable for a class of aerial vehicles (e.g., aircraft and fixed-wing UAVs, which cannot hover and have to maneuver constantly). Therefore, the vehicle’s steering controls are its lateral acceleration components in the pitch and yaw channels. In addition, we also consider nonlinear, coupled three-dimensional engagement kinematics between the vehicle and the target to preserve the inherent coupling between various channels and to achieve satisfactory control precision even if the channels are strongly coupled. Furthermore, we minimize a relevant weighted cost function to obtain the lateral acceleration components in the pitch and the yaw channels. We finally demonstrate the efficacy of our design via simulations.

A new approach to solving the problems of increasing the efficiency of geothermal field development

The initial prerequisites for the effective development of geothermal deposits have been developed. Geological – reliable information about the geological structure of thermal water deposits, compositions, physical and mechanical properties of rocks in the “water-rock” system. Technical – means of well construction, design features and technological capabilities corresponding to the conditions of the mining environment, ensuring the production of highly informative geological material in the form of a core, maintaining the stability of the walls of wells from collapse and shedding. A series of diamond drill bits with a hydrojet effect of rock destruction, corresponding to the conditions of opening hot springs, have been developed and tested in practice for drilling wells. A scheme of a circulation system for the opening and development of geothermal deposits consisting of a vertically injection and an obliquely ascending well connected by a smooth bend of an intermediate shaft is proposed. The ideological novelty of the scheme, which differs from all known schemes for the development of geothermal deposits in the world, provides for the possibility of creating conditions for the manifestation of the internal energy of the earth’s interior and the thermal horizon, aimed at improving the efficiency of the development of geothermal deposits. The structural features of the scheme are that a vertical injection well lined with a filter column in the section of the thermal horizon is made with ledges, where shock waves of increased and decreased pressure are generated when water is supplied, by dividing the water flow into a central core and lateral components. As a result, the thermal horizon is affected by alternating hydraulic impulses, an increase in rock permeability and an acceleration of water inflow into the well. At the same time, by linking the borehole system with an intermediate trunk, and laying an ascending well with an obliquely cased filter column, the volume coverage of the thermal horizon is provided, increasing the uninterrupted operation period, where the circulation channel from the lower ledge to the entrance to the tank with smoothly bending joints is made with one diameter. This eliminates local pressure losses. By grinding the wall of the intermediate shaft with rock hardening, water leaks and pressure losses along the length of the circulation channel are eliminated. The significance of the circulation scheme – the extraction of hot water is carried out by forced self-discharge, without attracting energy from outside.

Hydrodynamic Characteristics of Diagonal Brush Fish Pass: Prototype Measurements

The present study investigates the hydrodynamic characteristics of the diagonal brush upstream fishway at the Incirli run-of-river hydropower plant on Iyidere River in Turkey. Three-dimensional velocity measurements were conducted in the fish pass using a Micro acoustic Doppler velocimeter under real-time operation conditions. The diagonal arrangement of brush blocks creates favorable hydrodynamic conditions (i.e., lateral momentum exchange) that allow fish to minimize swimming energy. We found that the spatially averaged lateral component of Reynolds shear stress is 2.2 times higher than spatially averaged vertical component of Reynolds shear stress, which could be due to the lateral velocity gradient in the vicinity of brush blocks. It is shown that the low-velocity zones behind the brush blocks constitute important resting sites for fish. The monitoring data showed that inlet water levels have considerable effects on the turbulence quantities. The brushes become submerged with the increased reservoir water level from 102 m to 102.05 m above sea level. The maximum turbulent kinetic energy was increased by a factor of three compared to unsubmerged conditions. We found a strong relationship between the average energy dissipation rate per unit mass and the Reynolds number. On the other hand, the prototype data reveal the inverse relationship between the Darcy-Weissbach friction factor and the relative submergence of bristles. The present results allow the efficient design of diagonal fish passes.

Study of the aftershock sequence of the Oued Djer (Algeria) January 2nd, 2018 earthquake (Mw = 4.7) using a single station

The locality of Oued Djer, located about 40 km southwest of the city of Algiers, was hit by moderate earthquake Mw = 4.7 on January 2nd, 2018 at 20:59. We study this seismic event using locally recorded accelerograms. We located the main shock at (36.383°N; 2.568°E; 4 km) and we estimated its size that gives M0 = 1.2 E+16 N m (Mw = 4.7) using the inversion procedure. The obtained focal mechanism from the moment tensor estimation yields a reverse faulting solution with a small lateral component and a compression axis oriented NW–SE. We also, located 84 aftershocks events, using a single station, that gives a 2 km-long, 3 km-wide swarm which NE-SW trending and SE dipping. The aftershock hypocenters range from 4.4 km to 5.7 km. Our results are consistent with the seismotectonic context which suggest that the earthquake was related to the south westernmost edge of the Mitidja basin, underlined by a segment of the south Mitidja Fault System represented by the Blida Fault.

Effect of posterior capsular release on intraoperative joint gap mismatch in the mid-flexion range during posterior-stabilized total knee arthroplasty

IntroductionIntraoperative mismatch between extension and mid-flexion joint gaps remains a critical issue in posterior-stabilized total knee arthroplasty (PS-TKA). Posterior capsular release has been found to increase the extension joint gap. However, there is still a lack of robust evidence for the effect of posterior capsular release on the mid-flexion joint gap. The purpose of the present study was to quantify the effect of posterior capsular release on the intraoperative joint gap from extension through 45° mid-flexion to flexion and to clarify how this procedure might affect the improvement of gap mismatch in the mid-flexion 45° range. Materials and methodsIn total, 38 consecutive cases of primary PS-TKA were reviewed. The center, medial, and lateral component gaps from extension to flexion were measured with a tensor device before and after posterior capsular release. The minimal detectable change for joint gap measurement was calculated using two methods, error variance and intra-observer intraclass correlation coefficients. Pre- and post-release joint gap differences were assessed using the paired t-test. ResultsMinimal detectable change was found to be 0.59 mm. At 0° and 10° of flexion, the post-release center, medial, and lateral component gaps were significantly greater than at pre-release. At 45° and 90° and maximum flexion, there were no joint gap differences exceeding the minimal detectable change. The joint gap mismatches between 0° and 10°, and 45°, 90° and maximum flexion were significantly smaller at post-release than those at pre-release with the change values exceeding the minimal detectable change (P < 0.05). ConclusionPosterior capsular release significantly decreased both joint gap mismatch between extension and 45° mid-flexion, and extension and flexion, showing clinical usefulness in PS-TKA.

Experimental Study of the Seismic Behavior of a Prefabricated Low-Rise Steel Frame Structure with Hinged Joints

This paper investigated the seismic behavior of a prefabricated steel braced frame structure with hinged joints. Six steel frame specimens with different enclosure walls were tested under pseudo-static loading. The results indicated that the vertical load of the hinged braced frame system was mainly resisted by the beam and column members, and the lateral stiffness was completely provided by the bracing members. The final failure mode of all specimens was the failure of the bracings, while the beam-column members and the joints remained largely intact. The rigidly braced specimen was mainly damaged by buckling, yielding, and tearing, and the flexibly braced specimen was mostly damaged by buckling, yielding, and node failure. The energy dissipation of the specimens primarily depended on lateral force-resistant components such as braces and enclosure walls. Different building envelopes exert significant effects on the lateral stiffness and energy dissipation capacity of the structure. The ductility coefficient of all specimens ranged between 1.4 and 1.9, which indicates that the structural system mainly relies on lateral stiffness and elastic deformation to resist earthquakes, rather than structural ductility. The proposed prefabricated steel frame system with hinged connections has wide prospects of application in economically underdeveloped areas because of its convenience in transportation and installation.

Global performance of multi-story stiffness-eccentric RC structures subjected to progressive seismic excitations: Shaking table investigations

Asymmetric structures have demonstrated poor seismic performance while experiencing major earthquakes in the past. Such structures exhibit complex vibration characteristics under seismic shaking as there is coupling between the lateral and torsional components of vibration. These coupled vibrations tend to cause weak locations under torsional distress, which eventually leads to the global failure of the structure. This paper presents the experimental evaluation of a plan-asymmetric structure with stiffness eccentricity. The experimental investigation was conducted by means of shake table testing on a 1/4-scaled reinforced concrete (RC) frame shear wall structure exposed to progressive seismic excitations. The structural response is monitored from a global failure perspective both in the elastic and inelastic states under increased torsional vibrations. The experimental findings indicate that: (1) irregularities in a structure can lead to significant amplification of the dynamic response due to induced torsional vibrations (2) the damage in the structure influences the dynamic properties of the structure, which eventually tend to influence the global structural response (3) structural acceleration response is more sensitive to seismic excitations and appears to have more influence on local oscillations compared with structural displacement response and (4) floor rotations excessively increase with the increasing damage state of the structure. Based on the physical inspection and extracted measurements, the shear wall sustained severe damage, whereas beams and columns at the flexible edge of the structure formed plastic hinges in critical zones.

Hydrological and sediment connectivity under freeze–thaw meltwater compound erosion conditions on a loessal slope

Freeze-thaw processes can influence hydrology, soil erosion, and morphological development by altering the connectivity between active pathways of water and sediment transport. Concentrated flow experiments were conducted involving frozen, shallow thawed, and unfrozen soil slopes under 1, 2, and 4 L/min runoff rates at a temperature of approximately 5 °C. In this study, hydrological connectivity was analysed via the simplified hydrological curve and relative surface connection function. Sediment connectivity was analysed via the sediment structure connectivity and sediment functional connectivity. Results indicated that hydrological connectivity was greatest on frozen slopes (FS), followed by shallow thawed slopes (STS), and unfrozen slopes (UFS) given a constant flow rate. Hydrological connectivity increased with increasing runoff rate for each freeze-thaw condition. Freezing condition and runoff rate exhibited a positive response to the hydrological connectivity. Sediment structure connectivity increased with increasing runoff rate for each slope condition. The ordering of sediment structure connectivity across freeze-thaw condition was that FS was greater than STS while STS was greater than UFS independent of flow rate. Sediment functional connectivity included longitudinal, lateral, and vertical connectivity components. Sediment longitudinal and vertical connectivity indicated a trend of first increasing and then decreasing under the different runoff rates and freeze–thaw conditions. For a given runoff rate, the ordering of sediment longitudinal and vertical connectivity across freeze-thaw condition was that FS was greater than STS while STS was greater than UFS. Sediment lateral connectivity exhibited a trend of first decreasing and then stabilizing. The ordering of sediment lateral connectivity across freeze-thaw condition was that UFS was greater than STS while STS was greater than FS. FS could more easily reach longitudinal and vertical penetration. Sediment longitudinal and vertical connectivity rates demonstrated increasing trends with increasing runoff rate after runoff generation stabilization and gradually approached unity. This research further improves our understanding of the hydrological and erosional mechanisms of meltwater and the generation of flooding in frozen soil conditions.

Joint probability calculation of the lateral velocity distribution in strong field ionization process

We describe an approach to the description of the time-development of the process of strong field ionization of atoms based on the calculation of the joint probability of occurrence of two events, event B being finding atom in the ionized state after the end of the laser pulse, event A being finding a particular value of a given physical observable at a moment of time inside the laser pulse duration. As an example of such an physical observable we consider lateral velocity component of the electron’s velocity. Our approach allows us to study time-evolution of the lateral velocity distribution for the ionized electron during the interval of the laser pulse duration. We present results of such a study for the cases of target atomic systems with short range Yukawa and Coulomb interactions.

A scheme to measure velocity vector of a meteor by meteor radar

A scheme is proposed to measure velocity vector of a meteoroid with phase information of echoes from meteor radar. It is revealed that the phase variation of interfere signal of the multi-channel signals has a certain relationship with the lateral velocity component by mathematical analysis. Simulation results demonstrate that the velocity vector of a meteor can be inversed with the radial velocity and two lateral velocities using the proposed scheme. Results of two field experimental examples show both the vertical deceleration and acceleration, together with horizontal direction changing abruptly. • Two lateral velocities of meteoroid can be inversed by calculating phase difference of echoes from two pairs of channels. • A simulation was conducted to obtain velocity vector of a meteoroid by the common meteor radar of SKiYMET radar. • The error of inversed velocity vector is only about 2% in simulation results, suggesting the proposed scheme is feasible. • Using proposed scheme, velocity vector of meteoroid was deduced, which could help us better understand meteoroid's movement.