bluuebunny/crossref_metadata_2025 huggingface dataset:
Feasibility Design and Control of a Lower Leg Gait Emulator Utilizing a Mobile 3-Revolute, Prismatic, Revolute Parallel Manipulator
Authors: Soliman Ahmed , Ribeiro Guilherme A. , Gan Dongming , Rastgaar Mo
Published: February 2022

Design and control of lower extremity robotic prostheses are iterative tasks that would greatly benefit from testing platforms that would autonomously replicate realistic gait conditions. This paper presents the design of a novel mobile 3-degree-of-freedom (DOF) parallel manipulator integrated with a mobile base to emulate human gait for lower limb prosthesis evaluation in the sagittal plane. The integrated mobile base provides a wider workspace range of motion along the gait direction and reduces the requirement of the parallel manipulator’s actuators and links. The parallel manipulator design is optimal to generate the defined gait trajectories with both motion and force requirements using commercially available linear actuators. An integrated active force control with proportional integral derivative (PID) control provided more desirable control compared to traditional PID control in terms of error reduction. The novelty of the work includes the methodology of human data-oriented optimal mechanism design and the concept of a mobile parallel robot to extend the translational workspace of the parallel manipulator with substantially reduced actuator requirements, allowing the evaluation of prostheses in instrumented walkways or integrated with instrumented treadmills.
Flash-Boiling Characterization During Ingress of Coolant Event for Dust Issue in ITER
Authors: Blaisot Benjamin , Porcheron Emmanuel , Praud Olivier , Roig Véronique
Published: February 2022

Dust resuspension inside the vacuum vessel (VV) is one of the safety issues of the fusion reactor ITER. Plasma interaction with the plasma facing components (PFC) leads to their erosion, generating dust. One of the accident scenarios leading to dust resuspension is the ingress of coolant event (ICE) where a leak of the coolant pipes inside the VV conducts to injection and flash atomization of the cooling water. The metallic dust, produced by the erosion, is then oxidized by water throughout an exothermic reaction that produces hydrogen leading to a loss of confinement risk due to hydrogen and dust combustion. The steam flow, produced by the flash atomization of the liquid leaking from the breach, is considered to be the main source of dust resuspension. Therefore, experimentations about the two-phase flow generated by the flashing liquid jet are important to identify the main physical phenomena involved in the aerosol particles resuspension for ITER-like conditions that impose in particular low pressure level. Flash-boiling experiments were conducted under primary vacuum conditions. We studied the behavior and the structure of the flow resulting from superheated water injection into low pressure environment. Using shadowgraphy and particle image velocity (PIV), qualitative information and quantitative measurements on the two-phase flow that develops for different superheat conditions were gathered. The measured spray lateral spreading and droplets velocity are shown to increase with the superheat level. The use of a transparent nozzle also confirmed the strong coupling between the external structure of the atomized spray and the two-phase flow that develops upstream of the coolant circuit breach.
Steady-State Subchannel Thermalhydraulic Assessment of a Full-Scale Pressurized Water Reactor-Small Modular Reactor Fuel Assembly With Conventional and Advanced Fuels
Authors: Bayomy Ayman M. , Bromley Blair P. , Nava Dominguez Armando , Kelly Samuel
Published: February 2022

Thermalhydraulic analyses using subchannel codes (e.g., ASSERT-PV) are performed as a support tool to evaluate safety margins and the key parameters. Advanced fuels have recently attracted the international community's interest to improve safety margins during normal operation and accident scenarios by utilizing special coatings and barriers in a heterogeneous, multiregion, multicoating, multiclad annular fuel. In addition, advanced fuels improve the performance characteristics such as a higher burnup and better uranium utilization. Therefore, there is a need to understand the implications of such advanced unconventional fuels for the landscape of the Canadian nuclear industry and Canadian policy for energy development. In this work, subchannel thermalhydraulic analysis of a small modular reactor based on pressurized water reactor technology (PWR-small modular reactor (SMR)) core is performed using ASSERT-PV. A benchmark of a 17 × 17 fuel assembly with conventional fuel elements in comparison to PWR-SMR specification was conducted. The advanced fuel element system is also investigated and compared with the conventional one. The results indicated that the advanced fuel achieves a significant reduction in fuel element temperature by 15%. In addition, the results revealed that the proposed advanced fuel could achieve a minimum critical heat flux ratio (MCHFR) higher than the conventional fuel by 17%.
Transient Charging Characteristics of Shell and Tube Latent Heat Storage System—A Novel Two-Dimensional Analytical Approach
Authors: Agrawal Abhishek , Rakshit Dibakar
Published: February 2022

Energy storage using latent heat of solid–liquid phase change material (PCM) is an efficient option due to high energy density and low volume variation during phase change. Such type of storage is suitable to exploit untapped solar energy and waste heat energy. The present work explores the analytical approach to study the unsteady charging behavior of PCM inside latent heat thermal energy storage (LHTES) system. The radial, axial as well as temporal effects on the melting of PCM are investigated analytically. Relation between time, temperature, radius, and axial distance of storage system is developed using energy equation in cylindrical coordinates. The 49% reduction in melting time of PCM was noted with an increase in heat transfer fluid inlet temperature from 185 °C to 200 °C. It was also observed that melt front moves 1.28 times faster when axial position changes from 100 mm to 200 mm. Convection heat transfer plays a vital role during the charging process, and it is found that the melt front moves radially outward and axially upward during the melting of PCM. It can also be concluded that analytical tools like the one presented in this study can be instrumental in analyzing the thermal performance of storage units.
Effect of a Ceramic Matrix Composite Surface on Film Cooling
Authors: Wilkins Peter H. , Lynch Stephen P. , Thole Karen A. , Vincent Tyler , Quach San , Mongillo Dominic
Published: February 2022

Ceramic matrix composite (CMC) parts create the opportunity for increased turbine entry temperatures within gas turbines. To achieve the highest temperatures possible, film cooling will play an important role in allowing turbine entry temperatures to exceed acceptable surface temperatures for CMC components, just as it does for the current generation of gas turbine components. Film cooling over a CMC surface introduces new challenges including roughness features downstream of the cooling holes and changes to the hole exit due to uneven surface topography. To better understand these impacts, this study presents flowfield and adiabatic effectiveness computational fluid dynamics (CFD) for a 7–7–7 shaped film cooling hole with a 5 Harness Satin CMC weave at two orientations. To understand the ability of steady RANS to predict flow and convective heat transfer over a CMC surface, the weave surface is initially simulated without film and compared to previous experimental results. The simulation of the weave orientation of 0 deg, with fewer features projecting into the flow, matches fairly well to the experiment and demonstrates a minimal impact on film cooling leading to only slightly lower adiabatic effectiveness compared to a smooth surface. However, the simulation of the 90-deg orientation with a large number of protruding features does not match the experimentally observed surface heat transfer. The additional protruding surface produces degraded film cooling performance at low blowing ratios but is less sensitive-to-blowing ratio, leading to an improved relative performance at higher blowing ratios, particularly in regions far downstream of the hole.
Micro-Stereolithography for MEMS
Authors: Zhang X. , Jiang X. N. , Sun C.
Published: February 2022

Micro stereolithography (μSL) is a novel micro-manufacturing process which builds the truly 3D microstructures by solidifying the liquid monomer in a layer by layer fashion. In this work, an advanced micro stereolithography (μSL) apparatus is designed and developed which includes an Ar+ laser, the beam delivery system, computer-controlled precision x-y-z stages and CAD design tool, and in situ process monitoring systems. The 1.2 μm resolution of μSL fabrication has been achieved with this apparatus. The micro tubes with high aspect ratio of 16 and real 3D microchannels and micro cones arc fabricated on silicon substrate. For the first time, micro stereolithography of ceramic micro gears has been successfully demonstrated.
An Implicit Numerical Model for Electrophoretic Systems
Authors: Giridharan M. G. , Krishnan Anantha
Published: February 2022

An implicit finite-volume approach has been developed to solve the equations governing the electrophoretic process. The numerical procedure involves the sequential solution of the species conservation ionization equilibria and electro-neutrality equations in an iterative fashion until convergence. This implicit procedure is numerically stable and allows for faster steady-state solutions or larger time steps for time-accurate simulations. Temporal evolutions of pH, species concentrations and electrolyte conductivity are predicted. The results obtained using various higher order numerical schemes are compared and assessed. Results are presented for the isoelectric focussing, moving boundary electrophoresis, and capillary electrophoresis of amino acids and a protein. The predictions for the isoelectric focussing of albumin protein are in qualitative agreement with published experimental data.
Peristaltically Driven Flows for Micro-Mixers
Authors: Selverov Kiril P. , Stone Howard A.
Published: February 2022

Flows driven by a transverse travelling wave, propagating along a boundary of a closed rectangular container are examined, motivated by mixing with applications in MEMS. The steady, time-independent flow is computed analytically in the asymptotic limit of high frequencies and the boundary-layer structure is described. The results could be useful for modeling devices where streaming fluid motion needs to be produced without any internal moving parts.
Fabrication and Testing of a Multilayer Silicon Fluidic Laminar Proportional Amplifier
Authors: Piekarski Brett H. , Zeto Robert J. , Tenney Steve M. , Ervin Matthew H.
Published: February 2022

A multilayer fluidic laminar proportional amplifier (LPA) was fabricated from silicon wafers by using state-of-the-art photolithography and silicon deep-reactive ion-etching (DRIE) technologies. The assembled silicon amplifier showed a factor of 10 improvement in null offset when compared to an amplifier fabricated with traditional stainless steel laminates. Null offset is a measure of fabrication quality.

The pressure gain, which is a measure of performance, of the silicon amplifier was lower than expected. The low gain values resulted from a more faithful fabrication of the selected LPA design in silicon, producing a constricted flow condition. The same condition did not exist in the traditional stainless steel amplifier because patterning and overetching of the control features during photochemical milling widened the gap between the control edges beyond the designed value. The fabrication capability of the DRIE process has forced a reevaluation of the current LPA design.
Collection of Airborne Bacteria With Micro-Machined Virtual Impactor Arrays
Authors: Kenning Vanessa M. , Call Charles J. , Call Patrick T. , Birmingham Joseph G.
Published: February 2022

Collection of airborne bacteria (bioaerosols) is of interest for a variety of public health and national security concerns. A novel microfabricated virtual impactor device is being developed to concentrate bioaerosol particles in the 1 to 3 micron size range, which is typical of a single bacterial spore. The concentration is from a large to a small volume of air, with target concentration factors between 5 and 50. A virtual impactor uses the particle’s inertia to separate it from the main flow stream. Our design represents a significant departure from existing virtual impactor technology: the particle laden flow is directed into planar rows of virtual impactor elements. This novel architecture is described in detail in this paper. The use of computational fluid dynamics has led to designs in which each impactor row is specialized. Polystyrene latex (PSL) spheres simulate the bioaerosol particulates in our experiments. The experimental results show trends that do not correlate with the simulations. The data support our hypothesis that surface roughness may result in turbulent mixing within the virtual impactor elements, thereby reducing the effectiveness of the concentrator. Additional study of the effect of surface roughness and turbulence within the virtual impactor is planned.
Development of an Electromagnetically Actuated Mercury Microvalve
Authors: Adkins Douglas R. , Wong C. Channy
Published: February 2022

The development of microscale fluid handling components has been recognized as a crucial element in the design of microscale chemical detection systems. Recently, work has been undertaken at Sandia National Laboratories to construct a valve that uses a small mercury droplet to control the flow of gas through capillary passages. Electromagnetic forces that are provided by small permanent magnets and a current supply are used to drive the mercury into position. Driving the mercury droplet into a tapered passage halts gas flow through a capillary, while surface tension forces prevent the mercury from passing through the passage. Models have been developed to describe the movement of the mercury droplet and the sealing of the gas passage, and millimeter-scale units have been tested to explore design options. Predictions from the model show that a valve with 10 micron sized features can seal against pressures up to 1.5 atmospheres. Experiments have highlighted the promise of mercury valves and demonstrated problems that can arise from contamination of the mercury.
3-Way Microvalve for Pneumatic Applications Fabricated by Silicon Micromachining
Authors: Messner Stephan , Müller Martin , Schaible Jochen , Sandmaier Hermann , Zengerle Roland
Published: February 2022

A new normally-closed 3-way microvalve for pneumatic applications is presented. The valve is driven by a bimetallic actuation principle. This paper will discuss the dimensioning and design, the fabrication and the experimental results of the 3-way valve. The valve is designed to control differential pressures of 1000 kPa. Flow rates up to 800 ml/min for dry air at 600 kPa can be achieved. The power consumption is approximately 1.5 W. The valve has been tested successfully in an ambient temperature ranging from 0° to 50°C.
A Pneumatic Frequency Generator for Experimental Analysis of Unsteady Microflows
Authors: Colin Stéphane , Anduze Marc , Caen Robert
Published: February 2022

It is shown that the frequency analysis of pneumatic microchannels is experimentally limited to low frequencies, because of the large difference between the microchannels and the current pressure sensors areas. From this remark, a new pneumatic low-frequency generator has been devised. Firstly, the good quality of the sinusoidal pressure signal has been checked. Secondly, first experimental data have been obtained for microtubes about 100 μm in diameter; regarding the gain and the phase of the pressure signal, they show a good agreement with a previously elaborated model. Finally, the feasibility of performing measurements on smaller microchannels, with hydraulic diameters about 1 μm, has been demonstrated. Since it requires to associate several microchannels in parallel, first experimental measurements with a few microtubes in parallel have been made; they have confirmed theoretical predictions, with discrepancies in the same region as for data about millimetric systems reported in the literature.
General Contact and Hysteresis Analysis of Multi-Dielectric MEMS Devices Under Thermal and Electrostatic Actuation
Authors: He Yie , Marchetti James , Gallegos Carlos
Published: February 2022

Many MEMS devices which are thermally and/or electrostatically actuated contain moveable components which may undergo contact. The behavior is further complicated when hysteresis is exhibited after contact [1,2]. Generally, MEMS devices consist of multiple materials with different mechanical and electrical properties. These factors pose a challenge for modeling highly non-linear MEMS behavior.

This paper presents an improved approach to modeling contact and hysteresis between any two bodies in a MEMS device. In particular, the three assumptions are relaxed. First, previous methods for modeling contact were able to model only a single dielectric layer. The new approach is capable of modeling multi-dielectric layers. Second, previous modeling methods required the specification of contact faces. This restriction has been generalized to specifying contact entities. Third, previously, modeling methods required an air stop gap assumption above a conductor to avoid numerical difficulties in electrostatic calculations. The new approach developed removes the air stop gap assumption. More realistic mechanical contact is emulated. Electrostatic and thermal driven actuation is considered.

A number of case examples is presented to demonstrate the utility of the new contact and hysteresis approach. First a suspended test-beam structure is analyzed under different sets of boundary constraints and loading. Then, contact of an electrostatically actuated deformable mirror is analyzed.
Fabrication of 109.5° Micro V-Grooves Using a Two-Step Anisotropic Etching Technique
Authors: Chien Wen-Tien Chang , Lin Liwei , Lo Yi-Chung , Chang Chia-Ou
Published: February 2022

Design and fabrication of 109.5° V-grooves based on two-step anisotropic etching techniques are demonstrated and reported. This new process can expose planes other than the commonly used {111} surfaces to form new geometrical shapes. V-grooves of 109.5° are demonstrated by etching and exposing {112} planes on (100) wafers with anisotropic KOH etchants. Theoretical foundations are analyzed with experimental verifications. This new class of two-step etching process extends the capability of MEMS manufacturing to make new geometrical shapes and may have potential applications for device fabrications that requires non-conventional contours.
A Constrained Thermal Expansion Micro-Actuator
Authors: Cragun Rebecca , Howell Larry L.
Published: February 2022

This paper describes a series of thermal micro-actuators fabricated from polycrystalline silicon. These actuators use geometric constraints to amplify motion from thermal expansion. Compliant mechanism theory, particularly the pseudo-rigid-body model, was used to aid in the visualization of the device’s behavior. Nonlinear finite element analysis was used to analyze the actuators and refine the designs. The resulting mechanisms were fabricated and tested. Maximum deflections of over 20 μm were obtained with a total cycle time faster than 4 milliseconds. A bi-directional actuator capable of 6 μm displacements in both directions is also described.
Mechanical Optimization of a Dual-Axis Piezoresistive Force Sensor
Authors: Liang Yiching , Kenny Thomas
Published: February 2022

Micromachined cantilevers have been demonstrated to be effective measuring devices for small forces and displacements. Applications for such micro-electro mechanical systems include imaging of surface topography, data storage, and atomic force microscopy (AFM). Researchers at Stanford University have developed a piezoresistive sensor with independent vertical and lateral force detection capability using oblique ion implantation and high aspect-ratio plasma etching [1–3]. An SEM image of the device is shown in Figure 1. Although this device has been successfully used to obtain data and for servo control of a tracking system for a data storage device, its mechanical behavior has not been carefully studied. This device can be used to measure forces or deflections in various applications. This paper demonstrates how the device performance can be optimized for a specific set of requirements. Applications with different stiffness or bandwidth requirements may be designed using similar methods.
Ceramic Tape-Based Meso Systems Technology
Authors: Bau Haim H. , Ananthasuresh Suresh G. K. , Santiago-Avilés Jorge J. , Zhong Jihua , Kim Moon , Yi Mingqiang , Espinoza-Vallejos Patricio , Sola-Laguna Luis
Published: February 2022

Ceramic tape technology was initially developed for efficiently manufacturing interconnects and hybrid microelectronics circuitry through sequential printing and firing of conductor, resistor and/or dielectric paste formulations onto a substrate. Recently, it has been recognized that ceramic tapes can also be used as an efficient and convenient medium for the manufacturing of meso-scale electro-mechanical systems. In the green (pre-fired) state, the ceramic tapes consist of alumina particles, glass frit, and organic binder; and they are soft, pliable, and easily machinable. In each layer, one can machine flow conduits and mechanical devices and print electronic circuits. Very many layers can be stacked together to form complicated, three-dimensional, monolithic structures. These layers can be laminated and sintered. During the sintering process, the organic binder burns out, the glass flows, and the material hardens. It is possible to cast tapes of various ceramic composition to obtain desirable properties.

The paper describes mechanical, chemical, and thermal machining of prefired Low Temperature Co-fired Ceramic Tapes (LTCC); the dimensional changes occurring during the lamination and sintering processes; the use of sacrificial layers to prevent the sagging of internal suspended structures during the lamination and firing processes; the bonding of tapes to alumina, silicon, glass, and metals to form a hybrid technology; and the manufacturing of microchannels and a flow sensor in ceramic tapes.

Packaging is widely considered to be the Achilles heel of silicon-based MEMS technology since it is difficult to interface silicon MEMS devices with each other and fabricate relatively large, three-dimensional structures. Low Temperature Co-fired Ceramic Tapes (LTCC), the packaging material of choice in the electronics industry, hold the promise of alleviating some of these difficulties.
Self-Assembled Microslider for Microjoinery
Authors: Huang L.-S. , Sridharan B. , Kim C.-J. , Collins S. D. , González C. , Smith R. L.
Published: February 2022

MicroJoinery is an attractive concept to create precise translational movement for such components as optomechanical micro-accessories due to the readiness of silicon etching techniques. Basic fabrication of the dovetail MicroJoints uses anisotropic etching of (100) silicon wafers and fusion bonding. This paper focuses on a new fabrication method of self-assembly of the translational stage using a sacrificial layer and an electroplated microriveting technique, eliminating the need for wafer bonding and manual assembly. The slider is made from a double-side polished wafer and slides on substrate guided by a guide rail. The clearance between the sliding parts defined by the thickness of sacrificial layer is much smaller and repeatable than what bulk micromachining and manual assembly could provide. The coefficient of static friction was measured to be 0.42–0.78 in air for the self-assembled microslider with an added weight (3.5 g). For manually assembled dovetail MicroJoinery devices coated with silicon nitride, friction coefficient of around 0.302 was obtained.
Design and Fabrication of an Electrostatic Variable Gap Comb Drive in Micro-Electro-Mechanical Systems
Authors: Ye W. , Mukherjee S.
Published: February 2022

Polynomial driving-force comb drives are synthesized using numerical simulation. The electrode shapes are obtained using the indirect boundary element method. Variable gap comb drives that produce combinations of linear, quadratic, and cubic driving-force profiles are synthesized. This inverse problem is solved by an optimization procedure. Sensitivity analysis is carried out by the direct differentiation approach (DDA) in order to compute design sensitivity coefficients (DSCs) of force profiles with respect to parameters that define the shapes of the fingers of a comb drive. The DSCs are then used to drive iterative optimization procedures. Designs of variable gap comb drives with linear, quadratic and cubic driving force profiles are presented in this paper. Based on these designs, a comb drive which produces cubic polynomial driving force has been fabricated using the SCREAM I process.
Results of Mechanical Snubber Condition Monitoring on Degradation Rate Over Time
Authors: Shutt Mark
Published: February 2022

This paper summarizes the current results of Mechanical Snubber Condition Monitoring Programs implemented at certain operating US nuclear power plants. The condition monitoring is utilized to validate reliability and extend service life. Service Life Monitoring is a requirement of ASME OM. Subject operating units with large mechanical snubber populations instituted programmatic condition monitoring as early as 2005/2006. Degradation rates compared over time indicate that the programs resulted in an improvement in the reliability of the mechanical snubber population.
Pump Performance Requirements, Test Margins, and the Impact of Emergency Diesel Generator Voltage and Frequency Tolerances
Authors: Loebig Thomas G. , Swantner Stephen R.
Published: February 2022

Accurate calculation of pump performance margins relative to test acceptance criteria are driven by a variety of requirements and constraints. Inputs including design basis required performance, acceptance criteria assumptions, test conditions, and field versus vendor data are required. Test margin with respect to safety analysis limits may be more limiting than ASME Operations and Maintenance (OM) Code [1] inservice testing (IST) requirements. In response to component design basis inspection (CDBI) and design basis assurance inspection (DBAI) findings of potentially non-conservative equipment performance when operating at the extremes of Emergency Diesel Generator (EDG) Technical Specification (TS) limits of frequency and voltage, Westinghouse and the Pressurized Water Reactor Owner’s Group (PWROG) developed WCAP-17308-NP-A [2] to provide a simplified approach to incorporate these limits, by treating them as uncertainties, into design basis pump test acceptance criteria. The basic methodology provides a general approach to account for uncertainties by adjusting pump curves and test acceptance criteria. Depending on the magnitude of the EDG and instrument uncertainties, adjusted design basis related test acceptance criteria may challenge the tested performance of the pumps. Margin can be recovered by reducing uncertainties and taking credit for any available margin in the safety analyses.
Imaging inspired characterization of single photons carrying orbital angular momentum
Authors: Kumar Vimlesh , Sharma Varun , Singh Sandeep , Kumar S. Chaitanya , Forbes Andrew , Ebrahim-Zadeh M. , Samanta G. K.
Published: February 2022

We report on an imaging-inspired measurement of orbital angular momentum (OAM) using only a simple tilted lens and an intensified charged coupled device camera, allowing us to monitor the propagation of OAM structured photons over distance, which is crucial for free-space quantum communication networks. We demonstrate the measurement of OAM orders as high as ls = 14 in a heralded single-photon source and show, for the first time, the imaged self-interference of photons carrying OAM in a modified Mach–Zehnder interferometer. The described methods reveal both the charge and order of a photon's OAM and provide a proof of concept for the interference of a single OAM photon with itself. Using these tools, we are able to study the propagation characteristics of OAM photons over a distance, which is important for estimating transport in free-space quantum links. By translating these classical tools into the quantum domain, we offer a robust and direct approach for the complete characterization of a twisted single-photon source, an important building block of a quantum network.
Amplitude discrimination is predictably affected by echo frequency filtering in wideband echolocating bats
Authors: Tuninetti Amaro , Simmons Andrea Megela , Simmons James A.
Published: February 2022

Big brown bats echolocate using wideband frequency-modulated (FM) ultrasonic pulses, perceiving target range from echo delay and target size from echo amplitude. Echolocation pulses contain two prominent down-sweeping harmonics (FM1, ∼55–22 kHz; FM2, ∼100–55 kHz), which are affected differently by propagation to the target and back to the bat. Previous work demonstrates that big brown bats utilize the low frequencies in FM1 for target ranging, while FM2 only contributes if FM1 is also present. The present experiments test the hypothesis that the bat's ability to discriminate echo amplitude is also affected by selectively attenuating FM1 or FM2 in target or nontarget echoes. Bats were trained to perform an amplitude discrimination task with virtual echo targets located 83 cm away. Echo delay was fixed and echo amplitude was varied, while either FM1 or FM2 was attenuated by highpass or lowpass filtering. Bats' performance decreased when lower frequencies were attenuated in target echoes and when higher frequencies were attenuated in nontarget echoes. Performance was reversed in the opposite filtering conditions. The bat's ability to distinguish between virtual targets varying in amplitude at the same simulated range indicates a high level of focused attention for perceptual isolation of target from non-target echoes.
Identifying Bacterial Lineages in Salmonella by Flow Cytometry
Authors: Fernández-Fernández Rocío , Olivenza David R. , Sánchez-Romero María Antonia
Published: February 2022

Advances in technologies that permit high-resolution analysis of events in single cells have revealed that phenotypic heterogeneity is a widespread phenomenon in bacteria. Flow cytometry has the potential to describe the distribution of cellular properties within a population of bacterial cells and has yielded invaluable information about the ability of isogenic cells to diversify into phenotypic subpopulations.
The Khuvsgul Earthquake of January 12, 2021 (MW = 6.7, ML = 6.9) and Early Aftershocks
Authors: Emanov A. F. , Emanov A. A. , Chechel’nitskii V. V. , Shevkunova E. V. , Radziminovich Ya. B. , Fateev A. V. , Kobeleva E. A. , Gladyshev E. A. , Arapov V. V. , Artemova A. I. , Podkorytova V. G.
Published: February 2022

Abstract—The MW = 6.7, ML = 6.9 Khuvsgul (Khubsugul, Khövsgöl) earthquake occurred on January 12, 2021 in the Northern Mongolia close to the border of Russia. The earthquake caused ground shaking which reached intensity IX at the epicenter and was perceptible in the cities and villages of the Eastern and Western Siberia. The earthquake occurred in the region of the same-name fault and caused intense aftershock process on a segment between two fault’s bends. The fault segment encompassed by the aftershocks goes from the lake to the northwest. Seismic activation has involved a segment of the boundary of the ancient Tuva–Mongolian microcontinent hosting the parallel Khuvsugul and Darkhat rift depressions and the Busingol rift depression consisting of three linearly elongated troughs. Until the present, the region of the Busingol depression was distinguished by high seismicity, whereas the regions of the Darkhat and Khuvsgul depressions were characterized by moderate and low seismicity, respectively. The earthquake of 2021 is the largest earthquake that occurred on the Khuvsgul fault over the entire history. In less than two months, the level of the frequency–magnitude graph for the aftershocks has exceeded the level of the annual frequency–magnitude graph of the earthquakes for the Altai–Sayan mountain region. The aftershock density is nonuniformly distributed along the fault; the structure of the distribution is correlated to the unilateral block structure of the Earth’s crust east of the activated fault segment. The seismic potential of the Khuvsgul fault was estimated at Mmax = 7–7.5, and this earthquake, as suggested by the geological data, is not the maximum possible event. Given that seismic activation after the 1991 Busingol earthquake has not yet ceased, we have two strong activations in the Tuva–Mongolian block which can significantly affect evolution of its seismicity.
Comparative Analysis of the Methods for Estimating the Magnitude of Completeness of Earthquake Catalogs
Authors: Pavlenko V. A. , Zavyalov A. D.
Published: February 2022

Abstract—The magnitude of completeness $${{M}_{c}}$$ of the earthquakes above which 100% of events are thought to be reliably detected is a vital parameter characterizing the completeness of seismic data. A known fact is that to obtain correct estimates of the parameters of seismicity, it is compulsory to take into account $${{M}_{c}}$$ variations in space and time. In this work, we compare six modern methods for estimating $${{M}_{c}}$$. To compare the methods, we use event samples from real instrumental earthquake catalogs and synthetic catalogs generated based on the three models of magnitude distribution. We analyze the dependences of the two first moments of the distributions of $${{M}_{c}}$$ estimates on the shape of magnitude distributions and the sample size. We use three models corresponding to sample distributions that occur in the analysis of instrumental earthquake catalogs. Based on the obtained results, we formulate recommendations on selecting the suitable method for estimating the magnitude of completeness $${{M}_{c}}$$.
Knowledge and behaviour of community residents’ face mask-wearing during the COVID-19 pandemic: a cross-sectional study in Shanghai, China
Authors: Tang Huiyun , Wang Jian , Zhang Yuan , NI Jun , Liu Lei , Fang Jialiang
Published: February 2022

Objectives

COVID-19 is an infectious disease spreading through respiratory droplets. Using a face mask correctly is one of the essential preventive measures. We launched a survey to discover the current face mask-wearing problems for better prevention and control of the pandemic.

Setting/participants

A cross-sectional study was conducted with 1240 residents in Shanghai during 18–28 February 2020. Stratified random sampling was adopted in the urban area, urban–rural fringe area and rural area. A mobile self-designed questionnaire was used.

Main outcome measures

Analysis of the demographic and sociological factors influencing residents’ face mask type selection, disposable surgical mask-wearing behaviour, replacement time and the storage method for reuse of disposable surgical masks.

Results

The accuracy of residents’ face mask type selection was rated 41.61% (513/1233), and that of urban–rural fringe residents, low-education residents, elderly residents, were low, respectively (p<0.001). 96.67% of residents always wore face masks in crowded public places. Multiple-factor analysis showed that region, gender and education level were the influencing factors for entirely fitting the disposable surgical mask to the face. Region was an influencing factor for not touching the mask’s external surface while wearing or removing it. Education level was an influencing factor for recognising the external and inner mask surface, upper and lower edge of a disposable surgical mask. The accuracy of the mask replacement time was 25.63% (316/1223). It was low with elderly, low-education residents, respectively (p<0.001).The accuracy of residents’ storage method for reuse of disposable surgical mask was 3.81% (47/1233), and region, age and education level were influencing factors.

Conclusions

Shanghai residents recorded a high rate of wearing face masks. Selection of an appropriate type of face mask, disposable surgical mask-wearing behaviour, replacement time and storage method for reuse of disposable surgical masks should be particularly emphasised in future behaviour change interventions.
Towards quantifying the reciprocal associations between frequency of cannabis use and alcohol consumption: a cross-lagged analysis from the CONSTANCES cohort
Authors: Airagnes Guillaume , Matta Joane , Limosin Frédéric , Hoertel Nicolas , Goldberg Marcel , Zins Marie , Lemogne Cedric
Published: February 2022

Objective

Disentangle the temporal relationships between frequency of cannabis use and alcohol consumption.

Methods

A cross-lagged model providing standardised coefficients (SCs)±their standard errors in 13 255 men and 13 696 women enrolled in 2015 or 2016 in the French population-based 'CONSulTANts des Centres d'Examens de Santé' (CONSTANCES) cohort. Cannabis use was categorised as follows: ‘No use during the past 12 months’, ‘Use during the past 12 months but not in the past month’ and ‘Use in the past month’ for cannabis use at baseline, and No use during the past 12 months, ‘Use less than once per month’ and ‘Use once per month or more’ for cannabis use at 1 year of follow-up. Alcohol consumption was measured at baseline and at 1 year of follow-up and three categories were determined: low risk (<28 drinks per week in men; <14 drinks per week in women), moderate risk (≥28 and<42 in men; ≥14 and<28 in women) and high risk (≥42 in men; ≥28 in women). Analyses were adjusted for age, sex, education, income, tobacco consumption, self-rated health status and depressive symptoms.

Results

Both associations from alcohol to cannabis and from cannabis to alcohol were significant (SC=0.02±0.01 with p=0.003 and SC=0.06±0.01 with p<0.001, respectively). However, the SC of the association from cannabis to alcohol was three times higher than the opposite association (p<0.001). After stratification for sex, SCs of the association from cannabis to alcohol were more than two times higher than for the opposite association in men, and more than four times higher in women (both p<0.001).

Conclusions

The association between frequency of cannabis use and subsequent alcohol consumption was stronger than the opposite association. This finding encourages considering the risk of increased alcohol consumption among cannabis users.
Interprofessional evidence-based counselling programme for complementary and integrative healthcare in patients with cancer: study protocol for the controlled implementation study CCC-Integrativ
Authors: Valentini Jan , Fröhlich Daniela , Stolz Regina , Mahler Cornelia , Martus Peter , Klafke Nadja , Horneber Markus , Frasch Jona , Kramer Klaus , Bertz Hartmut , Grün Barbara , Tomaschko-Ubeländer Katrin , Joos Stefanie
Published: February 2022

Introduction

According to international literature, patients with cancer wish to have information on complementary and integrative healthcare (CIH). Medical guidelines recommend actively approaching patients with cancer discussing potential benefits and risks of individual CIH methods. While some CIH methods, for example, acupuncture and yoga, have been proven effective in high-quality studies, other CIH methods lack studies or bear the risk of interactions with chemotherapeutics, for example, herbal drugs. Therefore, an evidence-based interprofessional counselling programme on CIH will be implemented at four Comprehensive Cancer Centres in the federal state of Baden-Wuerttemberg, Germany.

Methods and analysis

A complex intervention consisting of elements on patient, provider and system levels will be developed and evaluated within a multilayer evaluation design with confirmatory evaluation on patient level. Patients with a cancer diagnosis within the last 6 months will receive three individual counselling sessions on CIH within 3 months (=intervention on patient level). The counselling will be provided by an interprofessional team of medical and nursing staff. For this purpose, an intensive online training programme, a CIH knowledge database and an interprofessional team-building process were developed and implemented (=intervention on provider level). Moreover, training events on the basics of CIH are offered in the outpatient setting (=intervention on system level). Primary outcome of the evaluation at the patient level is patient activation measured (PAM) with the PAM-13 after 3 months. Secondary outcomes, for example, quality of life, self-efficacy and clinical parameters, will be assessed at baseline, after 3 months and at 6 months follow-up. The intervention group (n=1000) will be compared with a control group (n=500, treatment as usual, no CIH counselling. The outcomes and follow-up times in the control group are the same as in the intervention group. Moreover, the use of health services will be analysed in both groups using routine data. A qualitative-quantitative process evaluation as well as a health economic evaluation will identify relevant barriers and enabling factors for later roll-out.

Ethics and dissemination

The study has been approved by the appropriate Institutional Ethical Committee of the University of Tuebingen, No. 658/2019BO1. The results of these studies will be disseminated to academic audiences and in the community.

Trial registration number

DRKS00021779; Pre-results.
Understanding stage of innovation of invasive procedures and devices: protocol for a systematic review and thematic analysis
Authors: Scroggie Darren L , Elliott Daisy , Cousins Sian , Avery Kerry NL , Blazeby Jane M , Blencowe Natalie S
Published: February 2022

Introduction

Surgical innovation has generally occurred in an unstandardised manner. This has led to unnecessary exposure of patients to harm, research waste and inadequate evidence. The IDEAL (Idea, Development, Exploration, Assessment, Long-term follow-up) Collaboration provided a set of recommendations for evaluating surgical innovations based on their stage of innovation. Despite further refinements and guidance, adoption of the IDEAL recommendations has been slow; an important reason may be that determining the stage of innovation is often difficult. To facilitate evaluation of surgical innovations, there is a need for a detailed insight into what stage of innovation means, and how it can be determined. The aim of this study is to understand the concept of stage of innovation as reported in the literature.

Methods and analysis

A systematic review is being conducted. Ovid MEDLINE and Embase databases were searched from their inception until July 2021 using an iteratively developed strategy based on the concepts of stage of innovation, invasive procedures or devices and guidance. Articles were included if they described an approach to evaluating surgical innovations in stages, described a method for determining stage of innovation, described indicators of stage of innovation, defined stages or described potential sources of stage-related information. Conference abstracts and non-English language articles were excluded. Other articles were detected from citations within included articles and suggestions from experts in surgical innovation. Data will be extracted regarding approaches to evaluating surgical innovations, methods for determining stage of innovation, indicators of stage of innovation, definitions of stages and potential sources of stage-related information. A thematic analysis will be conducted, and findings summarised in a narrative report.

Ethics and dissemination

Ethical approval will not be required. This systematic review will be published in a peer-reviewed journal and presented at appropriate conferences.

PROSPERO registration number

CRD42021270812.
Regulatory standards and guidance for the use of health applications for self-management in Africa: scoping review protocol
Authors: Bene Benard Ayaka , Ibeneme Sunny , Fadahunsi Kayode Philip , Harri Bala Isa , Ukor Nkiruka , Mastellos Nikolaos , Majeed Azeem , Car Josip
Published: February 2022

Introduction

Despite health applications becoming ubiquitous and with enormous potential to facilitate self-management, regulatory challenges such as poor application quality, breach of data privacy and limited interoperability have impeded their full adoption. While many countries now have digital health-related policies/strategies, there is also a need for regulatory standards and guidance that address key regulatory challenges associated with the use of health applications. Currently, it is unclear the status of countries in Africa regarding regulatory standards and guidance that address the use of health applications.

This protocol describes the process of conducting a scoping review which aims to investigate the extent to which regulatory standards and guidance address the use of health applications for self-management within the WHO African Region countries.

Methods

The review will follow the methodological framework for conducting a scoping study by Arksey and O’Malley (2005), and the updated methodological guidance for conducting a Joanna Briggs Institute (JBI) scoping review. Given that regulatory standards and guidance are unlikely to be available in scientific databases, we will search Scopus, Google, OpenGrey, WHO Regional Office for Africa Library (AFROLIB), African Index Medicus (AIM), websites of WHO, ITU and Ministries of Health, repositories for digital health policies. We will also search the reference lists of included documents, and contact key stakeholders in the region. Results will be reported using descriptive qualitative content analysis based on the review objectives. The policy analysis framework by Walt and Gilson (1994) will be used to organise findings. A summary of the key findings will be presented using tables, charts and maps.

Ethics and dissemination

The collection of primary data is not anticipated in this study and hence ethical approval will not be required. The review will be published in a peer-reviewed journal while key findings will be shared with relevant organisations and/or presented at conferences.