bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a Quaternary rock avalanche deposit (Central Apennines, Italy): Significance for recognition of fossil catastrophic mass‐wasting
Authors: Sanders Diethard , Dendorfer Teresa , Edwards R. Lawrence , Moseley Gina E. , Ortner Hugo , Steidle Simon
Published: February 2022

Whereas deposits of extremely‐rapid, ‘catastrophic’ mass wastings >105 m3 in volume (for example, the Marocche di Dro rock avalanche in the Southern Alps and the Flims rockslide in the Western Alps) are easily recognized by their sheer mass and blocky surface, the identification of fossil catastrophic mass wastings partly removed by erosion must be based on deposit characteristics. Herein, a ‘fossil’ (pre‐last glacial) rock avalanche, previously interpreted as either a till or debris flow, is described. The deposit, informally called ‘Rubble Breccia’, is located in the intramontane Campo Imperatore halfgraben that is bounded by a master fault with up to ca 900 m topographic throw. Based on documentation from field to thin section, and by comparative analysis with post‐glacial rock avalanches, tills and debris flows, the Rubble Breccia is reinterpreted as a rock avalanche. The Rubble Breccia consists of an extremely‐poorly sorted, disordered mixture of angular clasts from sand to block size. Many clasts show fitted subclast boundaries in crackle, jigsaw and mosaic fabrics, as diagnostic of catastrophic mass wasting deposits. Intercalated layers of angular to well‐rounded clasts of coarse sand to fine pebble size, and deformed into open to recumbent folds, may represent shear belts folded during terminal avalanche propagation. The clast spectrum of the Rubble Breccia – mainly shallow‐water bioclastic limestones, Saccocoma wackestones and other deep‐water limestones and dolostones – is derived from the front range along the northern margin of the basin. Calcite cement found within the Rubble Breccia was dated with the U/Th disequilibrium method to 124.25 ± 2.76 ka bp, providing an ante‐quam age constraint to the rock avalanche event. Because catastrophic mass wasting is a common erosional process, fossil deposits thereof should be more widespread than have been identified to date, although this may be a consequence of misidentification. The criteria outlined here provide a template to identify fossil catastrophic mass wasting deposits of any age.
Effects of elevated temperatures on the development of immature stages ofAnopheles gambiae (s.l.)mosquitoes
Authors: Agyekum Thomas P. , Arko‐Mensah John , Botwe Paul K. , Hogarh Jonathan N. , Issah Ibrahim , Dwomoh Duah , Billah Maxwell K. , Dadzie Samuel K. , Robins Thomas G. , Fobil Julius N.
Published: February 2022

Objective

This study investigated the effects of temperature on the development of the immature stages ofAnopheles gambiae (s.l.)mosquitoes.

Methods

Mosquito eggs were obtained from laboratory established colonies and reared under eight temperature regimes (25, 28, 30, 32, 34, 36, 38 and 40°C), and 80 ± 10% relative humidity. Larvae were checked daily for development to the next stage and for mortality. Pupation success, number of adults produced and sex ratio of the newly emerged adults were recorded. Larval survival was monitored every 24 h, and data were analysed using Kaplan–Meier survival analysis. Analysis of variance was used where data followed normal distribution, and a Kruskal–Wallis test where data were not normally distributed. Larval and pupal measurements were log‐transformed and analysed using ordinary least square regression with robust standard errors.

Results

Increasing the temperature from 25 to 36°C decreased the development time by 10.57 days. Larval survival (X2(6) = 5353.12,p< 0.001) and the number of adults produced (X2(5) = 28.16,p< 0.001) decreased with increasing temperature. Increasing temperatures also resulted in significantly smaller larvae and pupae (p< 0.001). At higher temperatures, disproportionately more male than female mosquitoes were produced.

Conclusions

Increased temperature affected different developmental stages in the life cycle ofAn.gambiae (s.l.)mosquitoes, from larval to adult emergence. This study contributes to the knowledge on the relationship between temperature andAnophelesmosquitoes and provides useful information for modelling vector population dynamics in the light of climate change.
"Tonal" Dodecaphony and Sentential Form: Extracts from Humphrey Searle's Symphony No. 2, Op. 33
Authors: Chandler Oliver
Published: February 2022

In an article written for The Musical Times in 1940, the English composer Humphrey Searle suggested the possibility of there being a "tonal center" in twelve-tone music. This vignette attempts to put analytical flesh on the bones of his argument. Using extracts from his Symphony
No. 2, Op. 33, I demonstrate how movement from relative consonance to dissonance and back (effected by means of pitch class–set expansion, shifts of macroharmony, and/or functionally suggestive row-area transpositions) can serve both to generate and to resolve structural tension. This
tendency is strengthened by traditional neighbor-note rhetoric (reminiscent of smooth nineteenth-century voice-leading transformations) and careful orchestration, as well as the second extract's use of a Classical formal type: an antecedent + continuation phrase hybrid theme.
Beyond Vierhebigkeit: Phrase Structure and Poetic Meaning in Three Lieder by Clara Schumann
Authors: Pedneault-Deslauriers Julie
Published: February 2022

This vignette illuminates various creative formal and phrase-rhythmic strategies devised by Clara Schumann that demonstrate her refined approach to phrase construction and text setting. Though some scholars have noted a certain "squareness" pervading Schumann's music, I argue that this
regularity often conceals deeper levels of complexity. In analyses of three Lieder, "Der Mond kommt still gegangen," "Die gute Nacht," and "Beim Abschied," and by building on recent studies applying Caplinian formal functions to vocal music, I demonstrate how Schumann overlays subtle formal
deviations, intricate textural patterns, and colorful harmonic twists to complicate the apparently uniform surfaces in order to craft original and powerfully expressive formal designs. Looking both beneath and above the foursquare surface phrasing reveals that Schumann fashions compelling
form-functional ambiguities and resolutions, which both enrich the surface Vierhebigkeit and compound the explicit meanings of the song texts.
Overview of Nuclear Piping Seismic Verification
Authors: Abe Hiroshi , Chokshi Nilesh
Published: February 2022

Nuclear power has gone through several transitional phases worldwide with early development, design, and construction in 1960s,1970s, and 1980s, particularly in Japan and US. There were some major research programs conducted during those years to develop methodology and prove the technology. Much of this knowledge is still very relevant and applicable and would be useful to young engineers and new professional coming to the nuclear industry. One of such programs is seismic verification of major structures, systems, and components (SSCs) by tests in Japan during the period of 1981 through 2004 at a large shaking table facility. Opportunities for conducting such large tests are not likely in the current environment of the industry and, therefore, one of the objectives of this paper is to summarize some earlier tests to raise awareness for the newcomers to the industry.

This paper discusses on Seismic verification tests of PWR and BWR Primary Loop, Main Steam and Feed Water line, Ultimate Strength of Piping and eroded piping , conducted in Japan. In particular, this paper focuses on: insights obtained from the test results; comparisons of test results with responses during actual earthquakes; collaboration of Japan and US in these tests; observations on robustness of Japanese seismic design; how the results relate to current issues; and use of these results from the future perspectives.
Reduced-Order Models for Effusion Modeling in Gas Turbine Combustors
Authors: Paccati Simone , Mazzei Lorenzo , Andreini Antonio , Facchini Bruno
Published: February 2022

Effusion cooling represents the state-of-the-art for liner cooling technology in modern combustion chambers, combining a more uniform film protection of the wall and a significant heat sink effect by forced convection through a huge number of small holes. From a numerical point of view, a high-computational cost is required in a conjugate computational fluid dynamics (CFD) analysis of an entire combustor for a proper discretization of effusion holes in order to obtain accurate results in terms of liner temperature and effectiveness distributions. Consequently, simplified CFD approaches to model the various phenomena associated are required, especially during the design process. For this purpose, 2D boundary source models are attractive, replacing the effusion hole with an inlet (hot side) and an outlet (cold side) patches to consider the related coolant injection. However, proper velocity profiles at the inlet patch together with the correct mass flow rate are mandatory to accurately predict the interaction and the mixing between coolant air and hot gases as well as temperature and effectiveness distributions on the liners. In this sense, reduced-order (RO) model techniques from the machine learning framework can be used to derive a surrogate model (SM) for the prediction of these velocity profiles with a reduced computational cost, starting from a limited number of CFD simulations of a single effusion hole at different operating conditions. In this work, an application of these approaches will be presented to model the effusion system of a non-reactive single-sector linear combustor simulator equipped with a swirler and a multi-perforated plate, combining ansys fluent with a matlab code. The employed surrogate model has been constructed on a training set of CFD simulations of the single effusion hole with operating conditions sampled in the model parameter space and subsequently assessed on a different validation set.
Flow Non-Uniformity and Secondary Flow Characteristics Within a Serpentine Cooling Channel of a Realistic Gas Turbine Blade
Authors: Baek Seungchan , Ryu Jaehyun , Bang Myeonghwan , Hwang Wontae
Published: February 2022

Unlike the ideal conditions considered in most previous studies, the actual cooling flow passage inside gas turbine blades is extremely complex. This complexity is due to the geometrical restrictions resulting from the external cooling holes and blade shape, which change the secondary flow and flow non-uniformity of the internal cooling flow. This study conducted an experimental and numerical analysis to characterize the secondary flow and flow non-uniformity in a realistic internal cooling serpentine passage. Magnetic resonance velocimetry was utilized to measure the average three-dimensional–three-components of the mean velocity. By integrating the flow field, parameters indicating the flow non-uniformity and secondary flow strength were obtained. Reynolds-averaged Navier–Stokes simulations were also conducted, and the Reynolds stress transport model showed relatively good performance when predicting the separation bubble in the U-bend. The secondary flow intensity exponentially decreases after the U-bend, but the rib turbulators maintain the secondary flow at a certain level. Additionally, the high-velocity regions in the inlet zone and beyond the separation bubble create significant flow non-uniformity and inherent shear. At the same time, the turbulence intensity becomes strong at the low-velocity region, which is key for heat transfer enhancement. Therefore, high flow non-uniformity has the potential to enhance heat transfer.
A Comparative Study of Thermal, Luminous, and Infrared Radiation Characteristics of Natural gas Flame in the Presence of Alkali, Alkali-Earth, and Transition Metallic Solution Additives
Authors: Pourhoseini S. H. , Naghizadeh N.
Published: February 2022

Experiments were performed to find out the effect of alkali, alkali-earth, and transition metallic additives on thermal, luminous, IR, and total radiative properties of natural gas flame. A total of 25 mL of 0.5 M alkali salts of NaNO3 and KNO3, alkali-earth salts of Ca(NO3)2, Ba(NO3)2, and Sr(NO3)2 and transition nitrate salts of Cu(NO3)2 and Mn(NO3)2 (Merck company) were prepared, and flame tests were done on each solution by using a Bunsen burner with the equivalence ratio of 1.05, which is close to the condition of stoichiometric air–fuel mixing. The optical characteristics of flame were measured in visible and infrared radiation (IR) spectrums by a TES-1332A luminance meter, BOMEM FTIR, and IR flame photography technique. Also, the total radiation was gauged by a HFP01 sensor. The results indicated that, in general, due to the increased rate of nucleation of intermediate soot particles, the flame in the presence of alkali metal additives has higher total, luminous, and IR radiation than in the presence of other metal additives. Also, the metallic additives do not significantly change the flame temperature. The results also revealed that although all metallic additives enhance the luminous radiation of flame, which is due to chemiluminescence phenomenon or atomic emission, luminous radiation of metal additives is negligible in comparison with their radiation in IR wavelengths. Furthermore, the results show that the boiling temperature of metallic salt solutions has a greater impact on flame luminosity than their ionization energy does.
Pressure and Power Generation During Explosive Vaporization on a Thin-Film Microheater
Authors: Zhao Z. , Poulikakos D. , Glod S.
Published: February 2022

When a liquid is superheated above its boiling point to temperatures near or at the homogeneous nucleation limit, the energy released could create a so-called explosive vaporization, if a significant fraction of this energy is manifested in the form of vapor expansion. In this study, a thin-film microheater (100μm × 110μm) was placed on the underside of a water layer. The surface temperature of the heater was rapidly (6μs) raised electrically, well above the boiling point of water. As a result, rapid vaporization took place. Due to its rapid growth, the vapor volume performs mechanical work on its surrounding and emits acoustic pressure waves. By measuring the acoustic emission from an expanding volume, the dynamic growth of the vapor microlayer is reconstructed where a linear expansion velocity of 17 m/s was reached. Using the Rayleigh-Plesset equation, an absolute vapor pressure of 7 bar was calculated from the data of the acoustic pressure measurement. The amount of extractable mechanical energy produced from the explosive expansion of a vapor microlayer on a thin-film microheater surface, its rate of production, and the energy conversion efficiency was also quantified in this work.
Micro-Fluidic Design and Fluid-Structure Interaction Analysis of a Micro-Pump
Authors: Beskok Ali , Warburton Timothy C.
Published: February 2022

Conceptual design of a reversible micro-pump system is demonstrated by numerical simulations. Unsteady, incompressible Navier-Stokes equations in a moving boundary system are solved by ΝεκΤαr, a spectral element (high-order) algorithm employing an Arbitrary Lagrangian Eulerian (ALE) formulation on unstructured meshes. The performance of the micro-pump is evaluated as a function of the Reynolds number and the geometric parameters. The volumetric flowrate is shown to increase as a function of the Reynolds number. However, the efficiency of the micro-pump decreases with increased Reynolds number, due to the increased leakage effects.
MEMS Based Actuators for Boundary Layer Control
Authors: Kumar S. M. , Reynolds W. C. , Kenny T. W.
Published: February 2022

Recent experiments and simulations have demonstrated the feasibility of active boundary layer control in turbulent flows. Reduction of skin friction drag requires the development of sensors, actuators and control algorithms to favorably modify the boundary layer close to the wall. In this work, the actuator side of the problem is addressed, with the goal of developing a realistic actuation technology for boundary layer control experiments, and eventually, for use in real boundary layer control applications. Design issues in flow control applications are discussed. A process for fabricating arrays of zero mass flux vortex generators is described. Finally, the mechanical and fluid dynamic characteristics of the actuators are presented.
Gas Transport by Thermal Transpiration in Micro-Channels: A Numerical Study
Authors: Wong C. Channy , Hudson Mary L. , Potter Donald L. , Bartel Tim J.
Published: February 2022

A reliable micro gas pump is an essential element to the development of many micro-systems for chemical gas analyses. At Sandia, we are exploring a different pumping mechanism, gas transport by thermal transpiration. Thermal transpiration refers to the rarefied gas dynamics developed in a micro-channel with a longitudinal temperature gradient. To investigate the potential of thermal transpiration for gas pumping in micro-systems, we have performed simulations and model analysis to design micro-devices and to assess their design performance before the fabrication process. Our effort is to apply ICARUS (a Direct Simulation Monte Carlo code developed at Sandia) to characterize the fluid transport and evaluate the design performance. The design being considered has two plenums at different temperatures (hot and cold) separated by a micro-channel of 0.1 micron wide and 1 micron long. The temperature difference between the two plenums is 30 Kelvin. ICARUS results, a quasi-steady analysis, predicts a net flow through the micro-channel with a velocity magnitude of about 0.4 m/s due to temperature gradient at the wall (thermal creep flow) at the early time. Later as the pressure builds up in the hot plenum, flow is reversed. Eventually when the system reaches steady state equilibrium, the net flow becomes zero. The thermal creep effect is compensated by the thermo-molecular pressure effect. This result demonstrates that it is important to include the thermo-molecular pressure effect when designing a pumping mechanism based on thermal transpiration. The DSMC technique can model this complex thermal transpiration problem.
Thin Film Microresonator for Vacuum Sensing
Authors: Yuan F. , Tom C. L. , Mastrangelo C. H. , Martin J. , Pfenninger R.
Published: February 2022

This paper reports the fabrication and testing of a silicon micromachined resonator suitable for vacuum sensing applications. The device consist of a circular bossed 1 mm-diameter, 5 μm-thick p++ silicon plate anodically bonded to a 7740 Pyrex glass wafer. The device is fabricated with 4 lithographic steps using the dissolved silicon wafer process. Both the resonator natural frequency and its quality factor are functions of gas pressure in the 101 – 10−4 Torr range.
Design of Resonant Beam Transducers: An Axial Force Probe for Atomic Force Microscopy
Authors: Harley Jonah A. , Chow Eugene M. , Kenny Thomas W.
Published: February 2022

Guidelines for the mechanical design of resonant beam force transducers are developed. By considering the effects of beam dimensions on the force sensitivity, it is shown that thin, narrow beams are optimal for resonant sensing. Sensitivity is also shown to be inversely dependent on the amplitude of oscillation, and linear with the resonance quality (Q) of the oscillator. Based on this analysis, an axial resonant force detector was developed for use in atomic force microscopy. Initial measured results in air with a Q of 15 and 60nm oscillations give 33nN force resolution in a 1 kHz bandwidth. The Q improves to 1200 in moderate vacuum, yielding an expected force resolution of 10pN in a 1 kHz bandwidth. Due to its high axial spring constant (∼200N/m) and vertical orientation, this force probe has the added benefit for surface force measurements that it is not susceptible to snap-down or other force instability.
A Micro-Actuator for a Hard-Disk Drive Fine Tracking Servo
Authors: Hirano Toshiki , Fan Long-Sheng , Lee Wen Y. , Hong John , Semba Tetsuo , Imaino Wayne , Pattanaik Surya , Chan Susanna , Webb Patrick
Published: February 2022

This paper reports on the design, fabrication and testing of an electrostatic micro-actuator for a magnetic Hard-Disk Drive (HDD) tracking servo. First, the design requirements for a micro-actuator in this application were investigated. These include high Z-directional stiffness, low in-plane stiffness, high structural aspect ratio, large output force, high area-efficiency, low cost, and mass-production by a batch process. A novel area-efficient rotary micro-actuator design was devised, and micro-actuators were successfully fabricated using innovative processing technologies such as high-aspect ratio polymer etching and thick metal electro-deposition. The fabricated micro-actuator has a structural thickness of 40 μm with a minimum gap/structure width of approximately 2 μm (aspect ratio of 20:1). The micro-actuator’s frequency response was measured and it was confirmed that the micro-actuator has extremely clean response up to very high frequency region, and this fact enables the design of a servo system that exceeds a 5 kHz servo bandwidth, which is adequate to achieve a track density of more than 25 kilo-track-per-inch (kTPI).

The micro-actuator/slider assembly was also tested on a spinning disk, with its position controlled by a PID controller using the magnetic position error signal (PES) written on the disk. A position accuracy of about 0.05 μm was observed when the servo controller was turned on. This result confirms that this micro-actuator can be used in a servo system which is capable of more than 25 kTPI.
Parametric Resonance in a Microelectromechanical Torsional Oscillator
Authors: Turner Kimberly L. , Hartwell Peter G. , Bertsch Fred M. , MacDonald Noel C.
Published: February 2022

In various MEMS devices, it has been observed that mechanical instabilities can occur with driving frequencies other than resonance[1]. One such device is the torsional scanning probe z-actuator with an integrated tip. Previously reported work identified five Matheiu instability frequencies, and an experimental map of the first two instability region[1]. In this paper, we extend that work to show the effects of damping on the instabilities. The motion of this system is described by Mathieu-type equations, which has been extensively studied theoretically, but damping of the system has prohibited most experiments from displaying the wide range of instabilities predicted by theory [2]. In our experiment, a laser vibrometer is mounted on an optical microscope to precisely measure device motion. We show that the boundary between stable and unstable solutions is extremely sharp. Behavior of the device near the instability boundaries can be applied to improvements filter technology and small force sensing.
Design and Strength Evaluation of an Anodically Bonded Pressurized Cavity Array for Wafer-Level MEMS Packaging
Authors: Go Jeung Sang , Cho Young-Ho
Published: February 2022

We present the design and strength evaluation of an anodically bonded pressurized cavity array, based on the energy release rate measured from the anodically bonded plates of two dissimilar materials. From a theoretical analysis, a simple fracture mechanics model of the pressurized cavity array has been developed. The energy release rate (ERR) of the bonded cavity with an infinite bonding length has been derived in terms of cavity pressure, cavity size, bonding length, plate size and material properties. The ERR with a finite bonding length has been evaluated from the finite element analysis performed for varying cavity and plate sizes. It is found that, for an inter-cavity bonding length greater than the half of the cavity length, the bonding strength of cavity array approaches to that of the infinite plate. For a shorter bonding length, however, the bonding strength of the cavity array is monotonically decreased with the ratio of the bonding length to the cavity length. The critical ERR of 6.21J/m2 has been measured from anodically bonded silicon-glass plates. A set of critical pressure curves has been generated for varying cavity array sizes, and a design method of the pressurized cavity array has been developed for the failure-free wafer-level packaging of MEMS devices.
Analysis on Multi-Layered, Corrugated Diaphragm With Residual Stress
Authors: Yan Hai , Lou Kuok Chun , Lee Byungchai , Kim Eun Sok
Published: February 2022

This paper describes the use of Finite Difference Method (FDM) to analyze a multiple-layered, corrugated rectangular diaphragm subject to residual stress for MEMS applications. The corrugated part of the diaphragm is treated as a flat plate with anisotropic mechanical properties. The multiple-layered structure is treated as a single-layered plate with an effective Young’s modulus. The effect of the residual stresses in the diaphragm layers is simulated with in-plane normal forces in the neutral plane at the four boundary edges of the diaphragm. This way, the complicated analysis on a corrugated, multiple-layered diaphragm with various residual stresses in the layers is greatly simplified, and can be done by FDM without sacrificing accuracy much. Both deflection and stress distribution of the diaphragm under a uniformly applied pressure have been analyzed, although the technique is also applicable for a non-uniform pressure. And we discuss the effects of corrugation depth, period and width on the deflection and stress distribution of the diaphragm. Finally, we describe an example of using this method to design a micromachined, corrugated-diaphragm, piezoelectric microphone in which the residual stress plays a critical role in limiting the performance.
Fracture and Sub-Critical Crack Growth Behavior of Micromachined Single Crystal Silicon Structures
Authors: Fitzgerald Alissa M. , Iyer R. Suryanarayanan , Dauskardt Reinhold H. , Kenny Thomas W.
Published: February 2022

Currently little data exists on the fracture and subcritical crack growth behavior of single crystal silicon, a common material for micromachined devices. In order to obtain stable crack growth in silicon, we utilize a decreasing stress intensity specimen geometry (Gonzales and Pantano, 1990). We present new data on crack growth rates in silicon as a function of applied stress intensity (K). We made direct measurements of these values via optical and electrical resistance techniques under monotonic loading conditions. We also present new data on the critical stress intensity (KIc) of silicon for a sample of micromachined proportions.
Thermal Flow Sensor for Liquids and Gases
Authors: Ashauer M. , Glosch H. , Hedrich F. , Hey N. , Sandmaier H. , Lang W.
Published: February 2022

A new type of a flow sensor is presented which is based on a thermal principle. The combination of two detecting methods results both in a considerable increase in measuring range (0.1 to 150 mm/s) and in a shorter reaction time of less than 2 ms. Furthermore, the sensor is relatively insensitive to pollution. Devices were manufactured and successfully tested for liquids and gases.
Suspended Moving Channels and Channel Actuators for Microfluidic Applications
Authors: Chong John M. , MacDonald Noel C.
Published: February 2022

A novel process for fabricating suspended moving channels has been developed. With this process we are able to produce microfluidic channels above the substrate as well as channels embedded just below the surface. By design, the process allows the core of single crystal silicon (SCS) beams to be removed leaving a hollow interior that can carry fluids. Thus, portions of actuators or entire actuators can contain and carry fluids. The result is total integration of channels with actuators and other high aspect ratio structures.

The nature of the process makes integration of these suspended channels with actuators extremely simple. Only two masks are required: one to define the actuators and another to define the channels. A third mask can be used to pattern the metal allowing for opaque and transparent channels. Suspending channels above the substrate opens a wide range of new possibilities: greater thermal isolation between channels; a method for mixing fluids; a means for pumping fluids; and a means for sensing density by monitoring resonance changes. In addition, the channels are accessible for both optical monitoring and optical excitation of chemical reactions.
Velocimetry for MEMS Applications
Authors: Wereley Steven T. , Meinhart Carl D. , Santiago Juan G. , Adrian Ron J.
Published: February 2022

Particle image velocimetry (PIV), a technique commonly used at macroscopic length scales to measure velocity fields of particle-seeded flows, is adapted to measure velocity fields in microfluidic MEMS devices, where micron-scale spatial resolution is critical. Adapting PIV to the microscopic level presents a number of challenges, including visualizing tracer particles that are smaller than the wavelength of light and minimizing errors due to the Brownian motion of the tracer particles. High numerical aperture video microscopy is used to record the faint signals from fluorescent 300 nm particles. Innovative ensemble averaging and adaptive spatial shifting algorithms are used to extract maximal information from the recorded images. The PIV technique is used to measure a low Reynolds number Hele-Shaw flow around an 8 μm human red blood cell. The velocity vector field presented has a maximal spatial resolution of 3.2 × 3.2 × 1.5 μm.
Microactuation by Continuous Electrowetting Phenomenon and Silicon Deep RIE Process
Authors: Lee Junghoon , Kim Chang-Jin “CJ”
Published: February 2022

This paper reports a new, deep reactive-ion-etching (DRIE) based microfabrication method to realize continuous electrowetting (CEW) for MEMS. CEW is a surface-tension driven actuation mechanism that drives a liquid-metal droplet along an electrolyte-filled microchannel by controlling the surface tension of the liquid metal with electric potential. DRIE process enables us to use silicon dioxide microchannel instead of the previously reported polymer which raised the question of long-term material compatibility between the electrolyte and channel material. The paper also discusses the design issues and scaling law to use CEW for microscale devices, revealing many advantages and justifying the CEW as a powerful microactuation principle for MEMS application. Experiment proved the effectiveness by demonstrating a low-voltage, low-power consumption, and high-speed operation in microscale. We obtained the speed of ∼10 cm/s for a mercury slug at an operating voltage less than 3 V and average current around 10 μA. A liquid micromotor with loop diameter of 2 mm demonstrates reliable operation (i.e., circling of the slug along the loop) at 420 rpm. Some of the possible applications include memory device, optical switch, microgyroscope, and angular inertial actuation device.
Anisotropic Crystalline Etching Simulation Using a Continuous Cellular Automata Algorithm
Authors: Zhu Zhenjun , Liu Chang
Published: February 2022

We present results on the development of an anisotropic crystalline etching simulation (ACES) program based on a new continuous Cellular Automata (CA) model. The program provides accurate modeling of etching process with high spatial resolution. Implementation of a dynamic CA technique has resulted in increased simulation speed and reduced memory requirements. A first ACES software based on PC platforms has been realized.
MEMS Codesign: First Full-System Inertial Microsensor Design Tool
Authors: Pottenger Michael D. , Kaiser William J.
Published: February 2022

We present the first inertial microsensor stand-alone simulation tool capable of modeling an entire sensor system, based on discrete-time methods and implemented in SPICE. Included are all electrical and thermomechanical noise sources, proof mass dynamics, differential capacitive transducer bridge, interface circuit, and feedback control. Complete microsensor system performance can be simulated in the time domain, incorporating flicker noise models based on measured data from a commercial CMOS process. Sensor design methodology, modeling and simulation concerns are addressed. Results appear in a companion paper also published in this volume.
ASME OM ISTB Code Vibration Changes: Vibration Calibration Frequency Response Range and Wording Changes
Authors: Hudson Edward , Anderson David , Camilli Nick
Published: February 2022

In July of year 2020, The Electric Power Research Institute (EPRI) Condition Based Maintenance User Group (CBMUG) held an annual meeting. During the proceedings, the group requested that an effort be made to pursue changes to ASME OM ISTB. Two changes were requested:

1. Changes to ISTB-3510 concerning calibration of vibration instruments at low frequencies.

2. Changes to various locations wording concerning the use of the term “broadband (unfiltered)” vibration data.

In July of 2020, EPRI submitted proposed changes to the ASME ISTB Code Committee and presented the requests during a virtual meeting.

Change 1: Operating Nuclear Plants are required by NUREG-1482 to follow ASME OM ISTB-3510(e) calibration requirements for vibration instruments used for in-service testing. Instruments accuracy must be ± 5% from 1/3 running speed to at least 1000 Hz. The industry has historically experienced difficulty in meeting this requirement on slow speed pumps resulting in proliferation of relief requests in the late 1980’s and early 1990’s. Revision of NUREG-1482 in 2013 caused concerns among users in relation to the validity of the existing reliefs.

Change 2: The term “Broadband Unfiltered” is used in various locations in the OM code to describe vibration data. This terminology was common in an earlier era of analog vibration data collection equipment but is confusing to a new generation of vibration analysts accustomed to using modern digital vibration instruments.
Plasma kinetics of c-C4F8 inductively coupled plasma revisited
Authors: Levko Dmitry , Shukla Chandrasekhar , Suzuki Kenta , Raja Laxminarayan L.
Published: February 2022

In this work, we improve the plasma kinetics of perfluorocyclobutane (c-C4F8), one of the most important gases in plasma etching applications. We use the self-consistent plasma fluid simulation model coupled with a comprehensive finite-rate chemical reaction mechanism. First, we discuss the deficiencies of the existing mechanisms of plasma chemical reactions found in the literature and the approach to improve these mechanisms. Second, we compare the results of our self-consistent simulations of inductively coupled plasmas in pure c-C4F8 with the experimental results obtained using the Gas Electronics Conference reference cell plasma reactor. Finally, we analyze the influence of various model parameters such as the surface reactions mechanism, gas pressure, discharge power, and electron stochastic heating length scale on the plasma parameters. We discuss how these parameters influence the kinetics of the dominant plasma species.
Improvement Predictors in a Workplace Program Promoting Healthy Lifestyle Habits
Authors: Kugathasan Thiffya Arabi , Gilbert Jo-Anne , Laberge Suzanne , Mathieu Marie-Eve
Published: February 2022

Background: The baseline characteristics of employees to predict improvements in healthy lifestyle habits (LHs) following workplace health promotion programs are underexplored. This study sought to identify predictors of improvements in physical activity (PA), eating habits, sleep habits, and stress management, and health risk factors resulting from healthy LHs. Methods: The Activate Your Health program included 3 packages of an increasing number of interventions: light, moderate, and high. Participating employees (n = 506) completed baseline and postintervention questionnaires that collected sociodemographic data, health- and LH-related variables, stress-related variables, and perceptions of general health and life satisfaction. Only those with the potential to improve were included in each improvement outcome analysis. Results: Being in high and intending to reduce alcohol consumption increased the odds of improving PA. Very good/excellent perceived general health, poor sleep habits, high alcohol consumption, and intending to improve stress management increased the odds of improving stress levels at work. Depression and intending to improve sleep habits increased the odds of improving stress management. Reporting feelings of pleasure increased the odds of improving body mass index. Conclusions: Baseline characteristics predicting improvements differed for each LH. A targeted approach may be needed to help employees improve LHs and related outcomes.
Versatile ginsenoside Rg3 liposomes inhibit tumor metastasis by capturing circulating tumor cells and destroying metastatic niches
Authors: Xia Jiaxuan , Ma Shaojie , Zhu Xi , Chen Chen , Zhang Ru , Cao Zhonglian , Chen Xing , Zhang Longlong , Zhu Ying , Zhang Shuya , Li Shiyi , Gu Guolong , Wei Xunbin , Yu Kunqian , Wang Jianxin
Published: February 2022

Limited circulating tumor cells (CTCs) capturing efficiency and lack of regulation capability on CTC-supportive metastatic niches (MNs) are two main obstacles hampering the clinical translation of conventional liposomes for the treatment of metastatic breast cancers. Traditional delivery strategies, such as ligand modification and immune modulator co-encapsulation for nanocarriers, are inefficient and laborious. Here, a multifunctional Rg3 liposome loading with docetaxel (Rg3-Lp/DTX) was developed, in which Rg3 was proved to intersperse in the phospholipid bilayer and exposed its glycosyl on the liposome surface. Therefore, it exhibited much higher CTC-capturing efficiency via interaction with glucose transporter 1 (Glut1) overexpressed on CTCs. After reaching the lungs with CTCs, Rg3 inhibited the formation of MNs by reversing the immunosuppressive microenvironment. Together, Rg3-Lp/DTX exhibited excellent metastasis inhibition capacity by CTC (“seeds”) neutralization and MN (“soil”) inhibition. The strategy has great clinical translation prospects for antimetastasis treatment with enhanced therapeutic efficacy and simple preparation process.
Follistatin promotes LIN28B-mediated supporting cell reprogramming and hair cell regeneration in the murine cochlea
Authors: Li Xiao-Jun , Morgan Charles , Goff Loyal A. , Doetzlhofer Angelika
Published: February 2022

Hair cell (HC) loss within the inner ear cochlea is a leading cause for deafness in humans. Before the onset of hearing, immature supporting cells (SCs) in neonatal mice have some limited capacity for HC regeneration. Here, we show that in organoid culture, transient activation of the progenitor-specific RNA binding protein LIN28B and Activin antagonist follistatin (FST) enhances regenerative competence of maturing/mature cochlear SCs by reprogramming them into progenitor-like cells. Transcriptome profiling and mechanistic studies reveal that LIN28B drives SC reprogramming, while FST is required to counterbalance hyperactivation of transforming growth factor–β–type signaling by LIN28B. Last, we show that LIN28B and FST coactivation enhances spontaneous cochlear HC regeneration in neonatal mice and that LIN28B may be part of an endogenous repair mechanism that primes SCs for HC regeneration. These findings indicate that SC dedifferentiation is critical for HC regeneration and identify LIN28B and FST as main regulators.
Protecting ice from melting under sunlight via radiative cooling
Authors: Li Jinlei , Liang Yuan , Li Wei , Xu Ning , Zhu Bin , Wu Zhen , Wang Xueyang , Fan Shanhui , Wang Minghuai , Zhu Jia
Published: February 2022

As ice plays a critical role in various aspects of life, from food preservation to ice sports and ecosystem, it is desirable to protect ice from melting, especially under sunlight. The fundamental reason for ice melt under sunlight is related to the imbalanced energy flows of the incoming sunlight and outgoing thermal radiation. Therefore, radiative cooling, which can balance the energy flows without energy consumption, offers a sustainable approach for ice protection. Here, we demonstrate that a hierarchically designed radiative cooling film based on abundant and eco-friendly cellulose acetate molecules versatilely provides effective and passive protection to various forms/scales of ice under sunlight. This work provides inspiration for developing an effective, scalable, and sustainable route for preserving ice and other critical elements of ecosystems.
Environmental DNA captures native and non-native fish community variations across the lentic and lotic systems of a megacity
Authors: Zhang Shan , Zheng Yitao , Zhan Aibin , Dong Chunxia , Zhao Jindong , Yao Meng
Published: February 2022

Globally, urbanization poses a major threat to terrestrial biodiversity, yet its impact on fish diversity is poorly understood, mainly because of surveying difficulties. In this study, environmental DNA metabarcoding was used to survey fish communities at 109 lentic and lotic sites across Beijing, and how environmental variables affect fish biodiversity at fine urban spatial scales was investigated. We identified 52 native and 23 non-native taxa, with lentic and lotic waters harboring both common and habitat-specific species. Water quality strongly affected native fish diversity, especially in lentic systems, but had little influence on non-native diversity. Fish diversity showed little response to urban land cover variation, but the relative sequence abundance of non-natives in lotic waters increased linearly with distance from the city center. Our findings illustrate the complex effects of urbanization on native versus non-native fishes in different aquatic habitats and highlight the distinctive considerations needed to conserve urban aquatic biodiversity.
Intestinal butyrate-metabolizing species contribute to autoantibody production and bone erosion in rheumatoid arthritis
Authors: He Jing , Chu Yanan , Li Jing , Meng Qingren , Liu Yudong , Jin Jiayang , Wang Yifan , Wang Jian , Huang Bo , Shi Lianjie , Shi Xing , Tian Jiayi , Zhufeng Yunzhi , Feng Ruiling , Xiao Wenjing , Gan Yuzhou , Guo Jianping , Shao Changjun , Su Yin , Hu Fanlei , Sun Xiaolin , Yu Jun , Kang Yu , Li Zhanguo
Published: February 2022

The imbalance between pathogenic and beneficial species of the intestinal microbiome and metabolism in rheumatoid arthritis (RA) remains unclarified. Here, using shotgun-based metagenome sequencing for a treatment-naïve patient cohort and a “quasi-paired cohort” method, we observed a deficiency of butyrate-producing species and an overwhelming number of butyrate consumers in RA patients. These outcomes mainly occurred in patients with positive ACPA, with a mean AUC of 0.94. This panel was also validated in established RA with an AUC of 0.986 in those with joint deformity. In addition, we showed that butyrate promoted T
regs
, while suppressing T
convs
and osteoclasts, due to potentiation of the reduction in HDAC expression and down-regulation of proinflammatory cytokine genes. Dietary butyrate supplementation conferred anti-inflammatory benefits in a mouse model by rebalancing T
FH
cells and T
regs
, as well as reducing antibody production. These findings reveal the critical role of butyrate-metabolizing species and suggest the potential of butyrate-based therapies for RA patients.
Intrinsic IL-2 production by effector CD8 T cells affects IL-2 signaling and promotes fate decisions, stemness, and protection
Authors: Kahan Shannon M. , Bakshi Rakesh K. , Ingram Jennifer T. , Hendrickson R. Curtis , Lefkowitz Elliot J. , Crossman David K. , Harrington Laurie E. , Weaver Casey T. , Zajac Allan J.
Published: February 2022

Here, we show that the capacity to manufacture IL-2 identifies constituents of the expanded CD8 T cell effector pool that display stem-like features, preferentially survive, rapidly attain memory traits, resist exhaustion, and control chronic viral challenges. The cell-intrinsic synthesis of IL-2 by CD8 T cells attenuates the ability to receive IL-2–dependent STAT5 signals, thereby limiting terminal effector formation, endowing the IL-2–producing effector subset with superior protective powers. In contrast, the non–IL-2–producing effector cells respond to IL-2 signals and gain effector traits at the expense of memory formation. Despite having distinct properties during the effector phase, IL-2–producing and nonproducing CD8 T cells appear to converge transcriptionally as memory matures to form populations with equal recall abilities. Therefore, the potential to produce IL-2 during the effector, but not memory stage, is a consequential feature that dictates the protective capabilities of the response.
Boron proxies record paleosalinity variation in the North American Midcontinent Sea in response to Carboniferous glacio-eustasy
Authors: Wei Wei , Yu Wenchao , Algeo Thomas J. , Herrmann Achim D. , Zhou Lian , Liu Jinhua , Wang Qian , Du Yuansheng
Published: February 2022

Salinity variation in ancient epicontinental seas has long been challenging to reconstruct. We determined salinity variation in the Late Pennsylvanian North American Midcontinent Sea based on normalized boron concentrations (B/Ga) and isotopic compositions (δ11B) of bulk shale. We analyzed the Stark Shale Member of the Missourian Stage Dennis Limestone cyclothem in the Charleston core (CC) from the Illinois Basin (eastward, more proximal) and the Iowa Riverton core (IRC) from the Midcontinent Shelf (westward, more distal). Both cores exhibited the same pattern of secular variation, with lower B/Ga and δ11B values at their base and top, recording less saline conditions during lower sea-level stands, and higher values in their middle part, recording more saline conditions at highstands—a pattern that conforms to conventional sequence stratigraphic and glacio-eustatic interpretations of Midcontinent cyclothems. At equivalent stratigraphic levels, B/Ga and δ11B values are systematically lower at CC relative to IRC, reflecting the generally lower salinity conditions of the Illinois Basin relative to the Midcontinent shelf, which is consistent with greater freshwater influence from the east due to heavy river runoff into the Appalachian foreland basin. Our findings serve to demonstrate the utility of paired B concentration and isotope data for paleosalinity analysis of deep-time shale formations.
What drives Fe depletion in calc-alkaline magma differentiation: Insights from Fe isotopes
Authors: Du De-Hong , Tang Ming , Li Weiqiang , Kay Suzanne Mahlburg , Wang Xiao-Lei
Published: February 2022

The continental crust is strongly depleted in iron relative to mid-oceanic ridge basalt, broadly identical to the calc-alkaline magmas, suggesting that calc-alkaline differentiation is key to continent formation. However, it remains contentious as to what drives Fe depletion during magmatic differentiation in the crust. The two competing hypotheses for calc-alkaline differentiation—magnetite versus garnet (± amphibole) fractionation—predict contrasting Fe isotopic fractionation pathways in evolved melts because magnetite preferentially depletes ferric, isotopically heavy Fe whereas garnet (± amphibole) does the opposite. We report whole-rock Fe isotope data for two suites of igneous rocks from the central Andes, which represent magmas traversing normal and thickened arc crust, respectively. The magmas traversing thickened crust show a strong Fe depletion trend and consistently high δ56Fe values (0.14‰ ± 0.02‰, 1 standard deviation [SD]), while those traversing normal crust are less depleted in Fe and show variable δ56Fe values (0.10‰ ± 0.05‰, 1SD). The two Andean suites are both isotopically heavier than Mariana arc (Pacific Ocean) magmas that differentiate along tholeiitic (Fe-enriching) paths. These results confirm that garnet (± amphibole) fractionation/retention is the primary driver of Fe depletion in calc-alkaline magmas, and highlight a role for crustal thickening in generating calc-alkaline magmas.