bluuebunny/crossref_metadata_2025_split huggingface dataset:
How many skin barriers haveth we: Percutaneous egression of ions?
Authors: Chiang Chavy , Maibach Howard I. 
Published: November 2021

AbstractIntroductionSkin provides critical barrier properties that enable terrestrial life. Myriad research has focused on the “water barrier” to transepidermal water loss (TEWL) despite there being a multitude of skin barrier properties. We asked what other barrier properties may have been overlooked and compiled data demonstrating the “electrolyte barrier” to be of potential clinical relevance.MethodsA literature search was conducted through PubMed, Embase, Google Scholar, and Web of Science databases for the following keywords: “transepidermal” or “epidermal” or “cutaneous” or “skin” or “percutaneous” and “ion” or “sodium” or “chloride” or “potassium” or “electrolyte” and “flux” or “egression.” Textbooks at the University of California, San Francisco were also hand reviewed. Experimental studies quantifying in vivo or ex vivo percutaneous egression of ions in response to human skin barrier perturbation were included.ResultsExperimental damage to skin, mostly by tape‐stripping, frequently induced increased ion flux rates through the epidermis, in addition to increases in TEWL values. Interestingly, barrier perturbation did not always result in a concomitant rise in TEWL and transepidermal ion flux rates, such as in delipidization, indicating a distinction between the two barriers.ConclusionQuantifying the percutaneous egression of ions in response to physical or chemical alterations may offer additional data that are not to be captured with TEWL studies exclusively. Continued efforts should be made to: (1) advance this technique as a method of assessing skin status and (2) enhance our understanding of other barriers and mechanisms.
Can the CutiScan CS 100® measure anisotropy and viscoelasticity in scar tissue after mastectomy? A reliability and validity study
Authors: Anthonissen Mieke , Van den Kerckhove Eric , Moortgat Peter , Geraerts Inge , Devoogdt Nele , De Vrieze Tessa , De Groef An 
Published: November 2021

AbstractBackgroundScars have different biomechanical characteristics, including anisotropy and viscoelasticity compared to healthy skin. To assess these characteristics, the CutiScan CS 100® can be used. The aim of the present study is to investigate reliability and validity of this device in breast cancer patients.Materials and methodsThirty female patients, with scar adhesions following mastectomy were assessed with the CutiScan CS 100®. Maximal distensibility (pixels) (V1), after‐suction return rate (pixels) (V2), and their ratio (%) (V3) at three points on and around the scar were assessed as measures of viscoelasticity. For intra‐ and interrater reliabilities, the intra‐class correlation coefficient (ICC) and its 95% confidence intervals were calculated. The standard error of measurement (SEM) was calculated to interpret reproducibility of these measurements. To investigate criterion validity of the measurement of anisotropy, measurements in the direction of healthy skin were compared with measurements in the direction of the scar, using a paired t‐test.ResultsV1, V2, and V3 show poor to moderate intrarater reliability (ICC 0.00–0.72) and interrater reliability (ICC 0.00–0.53). The maximum displacement (V1) on the measurement point above the scar shows the best reliability (ICC 0.33–0.72). The SEM is about the same for all parameters at all three points. The paired sample t‐test showed a significant difference (p < 0.05) between V1 in the direction towards the scar versus the measurement towards healthy tissue, on the point below the scar.ConclusionThese first reliability and validity results of the CutiScan CS 100® for measuring anisotropy and viscoelasticity in scar tissue adhesions after mastectomy seem promising. Further research is needed addressing the limitations of the present study design.
Conceptualizing careers: Is there an element of STEM in every profession?
Authors: Navy Shannon L. , Heisler Jennifer , Papa Jeffrey , Gjurkovitsch Anna 
Published: November 2021

AbstractScience, technology, engineering, and mathematics (STEM) is widely visible in education and workforce policies and discussions in the United States (US). However, there is a lack of consensus on what is considered a STEM career. In addition, little is known about how K‐12 teachers conceptualize STEM careers and how this information is portrayed to students. This mixed methods study investigated 52 K‐12 teachers’ conceptions of STEM careers and if they included this information in their classroom instruction. The data collected consisted of a questionnaire and follow‐up interviews with a subset of teachers. The data analysis revealed that there was a range of how teachers defined and conceptualized STEM careers from narrow to very broad. This led to the development of the STEM‐Peripheral, Adjacent, Central (STEM‐PAC) career classifications which categorizes careers based on the application of STEM knowledge and skills. Additionally, teachers articulated benefits and drawbacks of including STEM career information in their instruction. Benefits included increasing student interest in STEM careers and making learning relevant. Drawbacks included limits to teacher time and knowledge. This study suggests teachers should present STEM as it is connected to various careers and that administrators should support teachers who wish to include this in their curriculum.
Experimental and Numerical Assessments of the Effects of Vacuum and Solar Film on the Performance of a Low Concentration Eccentric Solar Collector
Authors: Teles Mavd P. R. , Ismail Kamal A. R. 
Published: November 2021

Abstract
Low concentration collectors are usually recommended for water heating and refrigeration systems. The literature reveals lack of information on numerical modeling, experimental data, and thermal performance of eccentric evacuated double tube solar collectors. This study is focused on eccentric solar collectors since this arrangement allows adequate concentration for achieving relatively high temperatures while having small size and occupying less space. The effects of the vacuum in the annular space and reflective film on the enhancement of working fluid heating and overall thermal performance were also assessed. An in-house numerical code using the finite volume method was used to discretize the conservation equations and the predictions were validated by experimental results obtained from an experimental rig that was constructed and instrumented for outdoor tests. The experiments were performed in the city of Campinas-Brazil during the autumn season. The investigated versions of the eccentric double tube solar collector include a version with a reflective film and vacuum, a second version with a reflective film but without vacuum, a third arrangement without a reflective film but with vacuum, and finally a version without both a reflective film and vacuum. The results showed that the version with reflective film and vacuum demonstrated high efficiency achieving 89%. The lowest efficiency of 42% was achieved by the version without both reflective film and vacuum. The comparative analysis of the four versions shows that the incorporation of reflective film increases the collector efficiency by 28%, while the vacuum increases the efficiency by about 1.3%.
Thermal and Hydraulic Performances of Porous Microchannel Heat Sink Using Nanofluids
Authors: Ahmed Zahir U. , Raihan Md. Roni , Ghaffari Omidreza , Ikhlaq Muhammad 
Published: November 2021

Abstract
Microchannel heat sink is an effective method in compact and faster heat transfer applications. This paper numerically investigates thermal and hydraulic characteristics of a porous microchannel heat sink (PMHS) using various nanofluids. The effect of porosity (γ = 0.32–0.60), inlet velocity (win = 0.5–1.5 m/s), and nanoparticle concentration (ϕ=0.0025 – 0.05) on thermal-hydraulic performance is systematically examined. The result shows a significant temperature increase (40 °C) of the coolant in the porous zone. The pressure drop reduces by 35% for γ = 0.32 compared to the non-porous counterpart, and this reduction of pressure significantly continues when γ further increases. The pressure drop with win is linear for PMHS with nanofluids, and the change in pressure drop is steeper for nanofluids compared to their base fluids. The average heat transfer coefficient increases about 2.5 times for PMHS, and a further increase of 6% in h¯ is predicted with the addition of nanoparticles. The average Nusselt number Nu¯ increases nonlinearly with Re for PMHS. The friction factor reduces by 50% when γ increases from 0.32 to 0.60, and the effect of nanofluid on friction factor is insignificant beyond the mass flowrate of 0.0004 kg/s. Whilst Cu and CuO nanoparticles help to dissipate the larger amount of heat from the microchannel, Al2O3 nanoparticle appears to have a detrimental effect on heat transfer. The thermal-hydraulic performance factor strongly depends on the nanoparticles, and it slightly decreases with the mass flowrate. The increase of nanoparticle concentration, in general, enhances both h¯ and ΔP linearly for the range considered.
The Influence of Initial Stresses and Boundary Restraints on the Nonlinear Vibrations of Cylindrical Shells
Authors: Evensen David A. 
Published: November 2021

Abstract
A Rayleigh-Ritz procedure is used in conjunction with nonlinear shallow shell theory to study the influence of axisymmetric initial stresses on the nonlinear flexural vibrations of thin-walled cylindrical shells. A similar formulation is used to determine the effect of in-plane boundary conditions on the nonlinear vibrations. Both analyses make use of an assumed vibration mode which possesses a moment restraint at the edges of the shell. The results show that compressive initial stresses cause the vibrations to become increasingly nonlinear as buckling is approached. Initial tensile stresses generally cause the vibrations to become more nearly linear. In-plane restraints on the axial displacement at the ends of the shell have a hardening influence on the nonlinear behavior. This influence is most pronounced for vibration modes with high axial wave numbers. A study of the moment restraint at the boundary shows that for thin shells, the conditions of simple-support are closely approximated by the present analysis.
Non-Linear Vibrations of Fluid-Filled, Simply Supported Circular Cylindrical Shells: Theory and Experiments
Authors: Amabili M. , Pellicano F. , Païdoussis M. P. 
Published: November 2021

Abstract
The large-amplitude response of thin, simply supported circular cylindrical shells to a harmonic excitation in the spectral neighbourhood of one of the lowest natural frequencies is investigated. Donnell’s nonlinear shallow-shell theory is used and the solution is obtained by Galerkin projection. A mode expansion including driven and companion modes, axisymmetric modes and additional asymmetric modes is used. In particular, asymmetric modes with twice the number of circumferential waves of driven and companion modes are included in the analysis. The boundary conditions on radial displacement and the continuity of circumferential displacement are exactly satisfied. The effect of internal quiescent, incompressible and inviscid fluid is investigated. The equations of motion are studied by using a code based on the Collocation Method. Validation of the present model is obtained by comparison with other authoritative results and new experimental results. The effect of the number of axisymmetric modes used in the expansion on the response of the shell is investigated, clarifying questions open for a long time. The contribution of additional longitudinal modes is absolutely insignificant in both the driven and companion mode responses. The effect of modes with harmonics of the circumferential mode number n under consideration is limited so far as the trend of nonlinearity is concerned, but is significant in the response with companion mode participation for lightly damped shells (empty shells). Results show the occurrence of travelling wave response in the proximity of the resonance frequency, the fundamental role of the first and third axisymmetric modes in the expansion of the radial deflection with one longitudinal half-wave, and limit cycle responses. A liquid (water) contained in the shell generates a much stronger softening behaviour of the system. Experiments with a water-filled circular cylindrical shell made of steel are in very good agreement with the present theory.
Robust Design Applied to Concurrent Parameter and Tolerance Selection
Authors: Gupta Rahul , Feng Chang-Xue Jack 
Published: November 2021

Abstract
This research discusses the robust design method for reducing cost and improving quality using the fractional factorial design approach. Robust design is proposed by Professor Genichi Taguchi to determine the optimum configuration of design parameters for better performance, higher quality and lower cost. The philosophy Taguchi recommends is sound and should be included in the quality improvement process of any organization. However, some methods of statistical data analysis and some approaches to the design of experiments, which he advocates, are unnecessarily complicated and sometimes ineffective. His sound engineering concepts can be combined with more efficient and effective experimental design and statistical data analysis methods. This is demonstrated by simultaneously optimizing the nominal value and the tolerances for a nonlinear RL electric circuit using the fractional factorial design approach instead of the Taguchi orthogonal array approach. Another contribution of this research is the incorporation of manufacturing cost data into the design stage.
Product/Component Information Field and Its Application to Concurrent Product Development
Authors: Qiao Lihong , Yang Zhibing , Zhang Chuck , Wang Ben 
Published: November 2021

Abstract
This paper presents a new modeling method for representing the spatial and configuration information involved for concurrent product development in design and its supporting processes. This method is called information field representation (IF-Rep). Based on this method, product/component models can be easily created — regardless of the complexity of the product/component — and are convenient to be used in various DFX processes to support design. This paper introduces applications of the IF-Rep and a key procedure in implementing IF-Rep modeling to support concurrent product development.
Thin Film NiTi Shape Memory Alloy Microactuator With Two-Way Effect
Authors: Gill John J. , Carman Gregory P. 
Published: November 2021

Abstract
Thin film SMA (Shape memory alloy) is a useful material for MEMS (Microelectromechanical Systems) actuator. This is because the thin film has an improved frequency response compared to bulk SMA, high work density, and produces large strain. A novel two-way thin film NiTi (Nickel Titanium) shape memory alloy actuator is presented in this paper. Thin film shape memory alloy is sputter-deposited onto a silicon wafer in an ultra high vacuum system. Transformation temperatures of the NiTi film are determined by measuring the residual stress as a function of temperature. Test results show that the Martensite-Temperature-Finish (Mf) is approximately 60° C, and the Austenite-Temperature-Finish (Af) is 110° C. A free standing NiTi membrane (12 mm × 12 mm and 2.5 μm thick) is fabricated using MEMS technology. We found that a mixture of HF (Hydro Fluoric Acid), HNO3 (Nitric Acid) and DI (Deionized) water with thick photo resist mask works best for the fabrication process. The membrane is hot-shaped into a dome shape. Results indicate that when the temperature of the NiTi film exceeds Af, the NiTi membrane transforms into the trained hot-shape. When the temperature cools down to room temperature, the membrane returns to the initial flat shape. The performance of the SMA micro actuator is characterized with a laser measurement system for deflection vs. input power and frequency response. The maximum deflection of SMA microactuator is 230 μm. The corresponding frequency responses at the maximum deflection are 30 Hz with Copper (Cu) block placed underneath the microactuator and less than 1 Hz when Plexi-glass is placed.
Cooling Effect of a MEMS Based Micro Capillary Pumped Loop for Chip-Level Temperature Control
Authors: Kirshberg Jeffrey , Yerkes Kirk , Trebotich Dave , Liepmann Dorian 
Published: November 2021

Abstract
Utilizing current Micro Electro Mechanical Systems (MEMS) technologies, a three-port micro-capillary pumped loop (micro-CPL) was designed, fabricated and tested to provide integral cooling to electronics or MEMS type devices. The two wafer design consists of one silicon and one borofloat glass wafer. An analytical study was used in determining the geometry of the device, including the evaporator dimensions (1000 μm × 2000 μm) and the length of the liquid and vapor lines (35 mm). Using laser spot heating, the finished device was run near steady-state. It was determined that the micro-CPL resulted in a backside cooling effect of at least 7 C when a laser delivering 7.5 W (+/− 0.2 W) with a spot-size diameter of 1.0 mm was focused on the front side of the evaporator region.
An Integrated SOI Optical Microswitch Using Electrostatic Micromirror Actuators With Insulated Touch-Down Beams and Curved Electrodes
Authors: Jin Young-Hyun , Seo Kyoung-Sun , Cho Young-Ho , Lee Sang-Shin , Song Ki-Chang , Bu Jong-Uk 
Published: November 2021

Abstract
We present an integrated SOI optical microswitch, composed of silicon waveguides and electrostatically actuated gold-coated silicon micromirrors. The optical microswitch serves as an optical signal transceiver containing an LD receiver and a PD transmitter. For lower micromirror switching voltage, we modify the conventional curved electrode microactuator into the new microactuator with touchdown beams. In addition, we simplify the structure and the process of the microswitch by using the ICP etching of SOI wafers. From the fabricated microswitch, we measure the switching voltage of 31.7±4V at the resonant frequency of 6.89kHz. Compared to the conventional microactuator, the touch-down beam microactuator achieves 87.4% reduction of the switching voltage. We observe the single mode wave propagation through the silicon waveguide with the measured micromirror loss of 4.18±0.25dB. We analyze major source of the micromirror loss, thereby presenting design guidelines for low-loss micromirror switches. We discuss a feasible method to reduce the switching voltage to 10V by reducing the residual stress of electrode insulation layer to 30MPa.
Scaling Relations for Piezoresistive Microphones
Authors: Saini Rahul , Bhardwaj Sunil , Nishida Toshikazu , Sheplak Mark 
Published: November 2021

Abstract
This paper presents a comprehensive model of a circular-diaphragm piezoresistive microphone. The structural characteristics of the diaphragm are developed as a function of both in-plane stress and transverse loading. The mechanical scaling for piezoresistor location and maximum sensitivity is given. The dynamics of the microphone are explored by combining the fundamental structural model with a lumped-element energy model. A description of the elements is given along with the frequency limitations of the lumped approximation for each element. This model is then used to provide insight into the key aspects of the dynamic response.
Design of a Micro Heat Engine
Authors: Xu C. , Hall J. , Richards C. , Bahr D. , Richards R. 
Published: November 2021

Abstract
The design for a totally new class of heat engine, a micro heat engine, which takes advantage of thermophysical phenomena unique to small scales, is introduced. The proposed engine is an external combustion engine, in which thermal power is converted to mechanical power through the use of a novel thermodynamic cycle which approaches the ideal vapor Carnot cycle. Mechanical power is converted into electrical power through the use of a piezoelectric generator. The generator, which takes the form of a flexible membrane, can be readily manufactured using MEMS fabrication techniques but still delivers high conversion efficiency. This approach eliminates the requirement to manufacture complex micromachines such as rotary compressors and turbines, resulting in a very simple but highly efficient device.
Design and Characterization of Small-Scale Sandwich Beams Fabricated by Photolithography and Electrodeposition
Authors: Sugimura Yuki 
Published: November 2021

Abstract
Small-scale sandwich beams with core structures having cell diameters and wall widths on the order of 500 μm and 100 μm, respectively, have been produced through fabrication methods that combine photolithography and electrodeposition. Two core configurations have been examined: 1) regular hexagonal honeycomb and 2) high-aspect ratio hexagonal shells having an open architecture. The bending response of the sandwich beams has been examined and compared with the beam theory predictions. Shear stiffness of the honeycomb core was considerably high and therefore the bending behavior was dominated by the face sheets. The bending of the sandwich specimens with the hexagonal shells, on the other hand, was largely dependent on the core. The sandwich beam dimensions investigated in this study have not been optimized for weight minimization and structural efficiency. Further advances in fabrication methods to produce micrometer-size features and high-aspect ratio cores will enable realization of structurally efficient, lightweight sandwich beams and panels that can be used as multifunctional components in small-scale devices.
Time-Periodic Forced Convection in Micro Heat Spreaders
Authors: Sert Cuneyt , Beskok Ali 
Published: November 2021

Abstract
A new micro heat spreader (MHS) concept for efficient dissipation of large, concentrated heat loads is introduced. The MHS is a single-phase, closed micro-fluidic system, which utilize time-periodic forced convection cooling. We verified the MHS concept by numerically simulating its operation under various conditions. Our parametric studies have shown that, unlike the steady laminar forced convection, the Nusselt number for time-periodic forced convection laminar flows have strong dependence on the Reynolds and Prandtl numbers. The increase in the Nusselt number indicates enhanced cooling capability of the MHS device. Based on our parametric studies, we calculated the optimum operation conditions, device dimensions and the maximum heat-dissipation rates.
A Hybrid Microfluidic Mini System Towards a “Lab-on-a-Chip” for Biochemical Immunoassay
Authors: Dharmatilleke Saman , Wijayawardhana C. A. , Okulan N. , Medis P. , Thomas J. H. , Henderson H. Thurman , Heineman William R. , Halsall H. Brian 
Published: November 2021

Abstract
Hand-held, fully automated microfluidic systems have been developed and characterized to perform a magnetic bead-based biochemical immunoassay. The magnetic beads were coated with a polymer on which a dendritic antibody had been prepared to form the basis of a “sandwich” immunoassay for sensing biomolecules. With the press of a button, a complete immunoassay is performed to detect biohazards, and the result of the assay is displayed on a LCD. One system was made by using biocompatible silicone tubing for interconnections between the devices while another system was fabricated on a micromachined “glass-on-silicon” motherboard (Dharmatilleke et al.,. 2000). The first system consists of four collapsible reservoirs for reagent storage, made of very thin biocompatible Teflon™; an array of zero dead volume pinch valves; two magnetic curtain magnetic particle separators; a micro wire electrode or IDA for detection; a flow sensor, a valveless rotary pump to pull the reagents through the microfluidic system and associated electronics. On the second system, the mini pinch valves have been replaced by “collapsible” membrane type zero dead volume valves and pumping is by peristaltic operation of the valves. This work preceeds the next step, which is an all-MEMS system “on-a-chip”.