Finger Width Research Articles

Fringing capacitance and tolerance of DRIE effect on the performance of bulk silicon comb-drive actuator

A bulk silicon comb-drive actuator with low driving voltage and large displacement is presented in this paper. The bulk silicon comb-drive actuator is fabricated by a simple bulk micromachining process based on the low temperature Au–Au bonding technology. A cascade folded beam is designed to improve the displacement of comb-drive actuator at low driving voltages. The instability of the whole system decreases by utilizing unequal wide comb fingers design. The fringing capacitance and the fabrication tolerances together with their effects on the performances of the comb-drive actuators are also discussed. The measurement results show that the capacitance change rate and the displacement change rate of the comb-drive actuator are 1.5 fF/V2 and 0.125 μm/V2, respectively. The displacement of the actuator can reach 28.5 μm at 15 V driving voltages. The experimental results of the comb-drive actuator are in good agreement with the modified theoretical predictions.

Effect of eigenvalue solution on the characteristics of double diffusive salt fingers

Double diffusive finger convection is driven by the varying diffusivity of the two components, contributing to the density variation. When the faster diffusing component heat stabilizes the system, and slow diffusing component salinity destabilizes the system with the overall density stratification remaining stable, the convection takes the form of rising and sinking fingers, which are known as salt fingers. We considered previous theories on the salt fingers’ growth rate, and show how different approaches to solve the same Eigen value equation lead to a different prediction of finger characteristics. We precisely solved the Eigen value growth rate equations, and show that the assumptions taken in the previous theories lead to unphysical system behavior in the limit of density ratio approaching unity. We show that the finger system becomes transient in this limit, and steady state assumption is not a valid approximation. Furthermore, other theories have also been proposed, and wide fingers are generally believed to transport larger fluxes when compared with thin fingers. In this paper, we show through numerical simulation that the assumption of wide finger-large flux ratio is not physically consistent in light of recent findings.

Lumped-Element Equivalent-Circuit Modeling of Millimeter-Wave HEMT Parasitics Through Full-Wave Electromagnetic Analysis

We present a broadband lumped-element parasitic equivalent circuit to accurately capture the frequency response of electromagnetic (EM) interactions inside the structure and surrounding environment of high electron-mobility transistors (HEMTs). A new mutual inductance term is included to account for the high-frequency magnetic field coupling between device electrodes. An analytical method is also proposed, for the first time, to extract the gate-to-drain mutual inductance $L_{\mathrm {MGD}}$ , which creates an undesirable inductive feedback path from output to input at millimeter wavelengths. Based on the suggested extrinsic equivalent circuit, we propose a novel multi-step parameter extraction procedure that utilizes direct analytic extraction and linear regression techniques systematically to determine the parasitic component values. The accuracy and robustness of the presented extraction algorithm are established via comprehensive comparisons between EM simulations, measurements, and frequency responses of the suggested equivalent circuits up to and beyond 300 GHz in the millimeter-wave (mmW) band. The key parasitic elements that are most detrimental to the microwave performance are identified and optimized through subsequent circuit analysis. Design guidelines are provided for optimum device layout selection to achieve the highest frequency performance. It is demonstrated through a full-wave simulation based parametric study that around 20% improvement in maximum oscillation frequency is achievable via optimization of device gate finger number and unit finger width.

All-printed humidity sensor based on graphene/methyl-red composite with high sensitivity

To monitor the most common constituted H2O in the air for health and environment applications, we propose a highly sensitive humidity sensor consisted of silver inter-digital electrodes and graphene (G)/methyl-red (M-R) composite layer. Dimension of the proposed silver inter-digital electrodes is 200 μm finger width, 400 μm spacing, and 400 nm thickness, which is fabricated on a low cost transparent polyethyleneterephthalate (PET) substrate through commercialized Dimatix material inkjet printer (DMP-3000). To achieve a high sensitivity and wide sensing range, the composite thin film layer is deposited over the silver inter-digital electrodes through electrohydrodynamic (EHD), and its thickness is ∼300 nm. The sensor electrical resistance inversely varies from 11 MΩ to 0.4 MΩ against the relative humidity (RH) content from 5% to 95%. The proposed humidity sensor showed 96.36% resistive and 2869500% capacitive sensitivity against humidity. The response and recovery time of the proposed sensor is 0.251s and 0.35s, respectively.

Carbon Microelectrodes for Real Time Osteoporosis Drug Screenings

Osteoporosis is a disabling skeletal disorder affecting 200 million people worldwide1. Presently, the main challenge is to develop new more effective drugs with reduced long-term side effects. Monitoring the interactions of diseased bone tissues with drugs is fundamental for osteoporosis drug development and screening. In vitro cytotoxicity assays represent the most commonly used approach for screening and validation of drug candidates in the early stage of drug discovery2. Most of these assays rely on two dimensional (2D) cell culture systems which do not allow for complex three dimensional (3D) spatial interactions (i.e. cell-cell and cell-extracellular matrix (ECM) interactions) typical in living bone and crucial for accurate results in toxicological testing3. Moreover, conventional 2D cytotoxicity screenings do not provide temporal information of the cellular response to drugs. Thus, there is a need for new and complementary 3D in vitro systems that can better mimic the in vivo microenvironment of bone architecture and enable in situ monitoring of bone cell response to osteoporosis drugs in real time. Conductive 3D substrates and scaffolds (e.g. based on metal, carbon, conductive polymers, etc.) offer the possibility for in-situ electrical sensing while providing a more in-vivo like microenvironment for real-time monitoring of cell population processes4. In the fabrication of 3D electrodes, limitations for high throughput, reproducibility, large-scale production and costs still remain a critical issue. Carbonaceous materials5, such as graphene, graphene foam, CNTs, diamond-like carbon, carbon composites and pyrolysed carbon are emerging for development of 2D and 3D electrodes. The carbon MEMS (C-MEMS) technique is a very simple and cost-effective method for electrode fabrication6, where a patterned polymer template is heated to temperatures above 900 °C in inert atmosphere to produce pyrolysed carbon electrodes. This process enables easy and reproducible fabrication of carbon electrodes with possibility for tailoring ad-hoc designs and sensitivities for specific applications7. Moreover, pyrolysed carbon electrodes exhibit a wide electrochemical potential window, chemical inertness towards a range of solvents and electrolytes, good biocompatibility, and the possibility to tune the electrical and mechanical properties of the electrodes. In order to monitor bone cell response to drugs in real time, 2D interdigitated pyrolysed carbon electrodes (IDE) have been designed and fabricated with the C-MEMS technique, using SU-8 as photoresist to define the polymer template on a Si-based substrate (Figure 1A). The IDEs are composed of two combs, one used as working (WE) and one used as counter electrode (CE). Three different designs have been evaluated by varying finger width and spacing, i.e. width/spacing of 5/8.4, 12/15, 30/30 µm. Electrochemical characterization has been performed using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Figure 1B shows cyclic voltammograms related to the 30/30 µm design performed in a solution of 1 mM ruthenium (II/III) hexamine chloride in PBS at a scan rate of 100 mV/s. For the same chips impedance spectra were recorded in PBS in the frequency range of 0.1 – 100000 Hz by applying 1 mV sinusoidal potential (Figure 1C). Analogue behaviors have been observed for the other geometrical designs. In order to validate the electrodes for impedance-based cell assays, adhesion and proliferation of a human osteoblastic model cell line (Saos-2) was assessed in real time. First, the effect of carbon-coated surfaces (i.e. laminin, collagen, fibronectin) on Saos-2 cells was evaluated and compared with the traditionally used polystyrene (data not shown). Fibronectin coating was shown to better promote cell adhesion and proliferation (Figure 1D inset). Saos-2 cells were seeded in a concentration of 140000 cells/cm2 on a fibronectin coated (20 µg/mL) carbon chip maintained at 37° C in a humidified atmosphere having 5% CO2 and impedance spectra were acquired every hour for 48 hours. Figure 1D shows the normalized impedance (Cell Index) profile over time, providing indication on the temporal evolution of cell adhesion and proliferation until reaching confluence. These results indicate that carbon electrodes are suitable for EIS-based cellular assays using osteoblastic cells and pave the way for the development of 3D in vitro cytotoxicity models of bone tissue for osteoporosis drug screenings.

Dark Current Suppression of Germanium Photodiode Using Metal-Interlayer-Semiconductor-Metal Structure with TiO2 interlayer

Germanium (Ge) photodetectors (PDs) are promising optoelectronics device for advanced Si photonics and optical interconnection due to excellent absorption property, near-infrared wavelengths, and process compatibility with Si-based complementary metal-oxide-semiconductor (CMOS). Ge metal-semiconductor-metal (MSM) PDs have many advantages over Ge PIN PDs in terms of low capacitance, high bandwidth, and process simplicity. However, Ge MSM PDs have large dark current because of a low hole barrier height induced by severe Fermi-level pinning between the metal and Ge, which results in poor sensitivity and large power consumption of PDs. In this work, the dark current of Ge MSM PD was tremendously reduced by introducing asymmetric metal-interlayer-semiconductor-metal (MISM) structure [Fig. 1]. As shown in Fig 2, a thin TiO2 layer was selected as the interlayer to reduce hole dark current by enhancing the hole Schottky barrier and the proposed structure can collect the photo current efficiently due to almost zero conduction band offset between TiO2 and Ge. Low p-type Ge wafer was used to minimize bulk defect current. To form MISM structure, TiO2 interlayer was deposited by atomic layer deposition (ALD) system at process temperature of 250 °C. To increase responsivity, finger-type PD was used with 10 um finger spacing and 10 um finger width. Metal-semiconductor (MS) contact region is defined by e-beam lithography and etched by 6:1 buffered HF, then metal-interlayer-semiconductor (MIS) contact region is defined by e-beam lithography. Cu contact was formed by e-beam evaporation and lift off process. As a result, MISM structure exhibits tremendous dark current reduction by approximately 4,000 times at a bias voltage of 1 V. The dark current reduces as the TiO2 thickness increases as shown in Fig. 3. In case of 1 nm-thick TiO2 interlayer the dark current is hardly reduced compared to symmetric MSM structure because most of holes can flow through 1 nm-thick TiO2 interlayer by tunneling. The hole dark current from the metal side diminishes as TiO2 thickness increases because hole tunneling probability decreases. The dark current with 3 nm-thick and 5 nm-thick TiO2 is reduced by 64 times and 3,970 times at 1 V, respectively, from symmetric MSM structure. As shown in Fig. 4, photo I-V measurement was carried out on asymmetric Ge MISM PD with 5 nm-thick TiO2 interlayer with collimated infrared laser (λ=1.55 um). Measured photo current value was 0.2 mA and it was saturated at 0.6 V, and the sensitivity of the PD was 24.52 at 1 V. In summary, we tremendously suppress dark current by approximately 4,000 times at 1 V using MISM structure. TiO2 interlayer of asymmetric MISM structure efficiently decrease hole dark current, and this structure can be promising structure for dark-current suppression in Ge MSM PD. Figure 1

Focused Ion Beam Reduced Graphene Oxide Micro-Supercapacitors with Unprecedented Energy and Power Densitites

Miniaturization of energy storage devices with high energy and power densities can reduce the footprint of micro-devices being used in our daily life. Micro-supercapacitors with planar geometries offer several advantages, such as, the ability to control and reduce the distances ions travel between two electrodes, easy integration to micro devices as the separator and the electrodes are in the same plane, and offer the potential of being extended into 3D without compromising the inter-electrode separation distances. In this study, we have used focused ion beam technology (which is capable of producing reduced graphene oxide patterns and complex shapes in insulating films of graphene oxide with a possible spatial resolution down to ~20 nm in a mask-less and direct write approach) to directly write miniaturized planar electrodes of reduced graphene oxide on films of graphene oxide (GO). We have optimised the ion-beam irradiation and have investigated the influence of ion beam irradiation on the resultant microstructure and the electrochemical properties of the resultant reduced graphene oxide films. Subsequently, using the optimized ion-beam irradiation, interdigitated electrode designs (40 μm long and 3.5 μm wide fingers with ultra-small inter-electrode spacing of 1 μm) have been generated, which have demonstrated a large capacitance (102 mF/cm2), ultra-small time response (0.03 ms), low equivalent series resistance (0.35 mΩ cm2), and have retained 95 % of the specific capacitance after 1000 cycles at an ultrahigh current density of 45 mA/cm2. These performance metrics show unprecedented improvements on several aspects of supercapacitor performance over existing reports due to the miniaturized electrode dimensions and minimal damage to the graphene sheets. We believe our results can provide opportunities for large-scale fabrication of arrayed, planar, high performance micro-supercapacitors with a small environmental footprint.

Correlations of viscous fingering in heavy oil waterflooding

In order to include viscous instability in modeling heavy oil waterflooding, it is essential to predict the nature of viscous instability. It is still unclear as to whether previous findings of viscous fingering in immiscible displacements in the presence of high single-phase permeabilities and linear displacement schemes are valid in displacement schemes similar to oil-field patterns (e.g., five-spot) and what the effect of dispersion (caused by varying velocity profiles) is on viscous fingering. To overcome the limitations of previous studies of viscous fingering in immiscible displacements, we conduct experiments in low-permeability, one-quarter five-spot patterns. The correlation of experimentally measured oil recoveries, pressure drops, saturation profiles, viscous fingers length and width, dynamic population of fingers, and rate of growth of fingers population with time and front position are discussed. Study of viscous fingering patterns in heavy oil waterflooding conducted in this work provides new insights into the onset of fingering and fingers development.

Comparative study of low-frequency noise in 0.18 μm and 0.35 μm gate-length nMOSFETs with gate area of 1.1 μm2

We analyzed the noise characteristics of 0.18μm and 0.35μm nMOSFETs with a gate area of 1.1μm2 in the frequency range of 1Hz to 100kHz. Both two- and four-finger devices were investigated and analyzed. The experimental results show that the noise of 0.35μm gate-length nMOSFET possesses lower 1/f component than the 0.18μm one, whereas the four-finger devices reveal less 1/f noise than those of with two-finger ones. Furthermore, we used time domain measurement of drain current and also the statistical analysis of wafer level on the random telegraph signals (RTS) tests, and the results showed that RTS noise is higher in devices with a 0.35μm gate-length, and devices with a smaller gate finger width produce more RTS noise than devices with a larger gate finger width.

Laser fabrication of all-solid-state microsupercapacitors with ultrahigh energy and power based on hierarchical pore carbon

Microsupercapacitors (MSCs) are used as power sources or energy storage units in microelectronic devices. This study fabricates all-solid-state MSCs using a laser for the micromachining of substrates coated with activated mesophase pitch (aMP) to produce in-plane interdigitated microelectrodes for use in conjunction with gel-state electrolytes. Due to the inclusion of hierarchically-connected micropores and mesopores, aMP carbon has considerable capability for charge storage and the delivery of energy at high rates. Through reduction in the finger width, the proposed laser-patterned design substantially reduces the resistance to ion drift in the electrolyte bulk and ion diffusion across the carbon-film network. The use of an ionogel enables the MSC to reach stack capacitance of 12Fcm−3, stack energy of 16mWhcm−3, and stack power of 160Wcm−3. These energy and power values approach those obtained from thin-film lithium ion batteries and aluminum electrolytic capacitors, respectively; this synergy between high energy and power is unprecedented for MSCs. The proposed MSCs exhibit outstanding cycling stability and those using ionogel present high thermal stability. The proposed fabrication methods enable the on-chip integration of microelectronic devices and therefore provide an opportunity for the development of a variety of micro/nano-sized energy devices.

Phosphorus Influence on Plant Tissue Nitrogen Contents and Yield Attributes of Finger Millet Varieties in Semi-arid Region of Kenya

The experiment was conducted with the aim of evaluating the effect of differential levels of P on finger millet accumulation of N and yield components. On-station experiments were conducted at the KALRO-Kiboko crops research station in Makueni County during the short and long rains of 2014 and 2015 respectively. There were 4 levels of P (0, 12.5, 25 and 37.5 kg ha-1 P2O5) and three varieties (U-15, P-224 and Ekalakala). Ekalakala was the local check while 0 kg/ha P2O5 was the control. The trial was laid out in a randomized complete block design and fitted in factorial arrangement with three replicates given a total of 36 plots. Soil sampling was at a depth of 0-30 cm on all the plots and analytical results showed moderately available P but very low N, organic carbon and zinc. Significant differences (P=.05) were observed between the phosphate levels on the nitrogen contents in plant parts with the control showing the lowest N accumulation of 4.95% and 4.90% for the short and long rains respectively while the 25 kg ha-1 P2O5 rate had the highest with 5.66% in the short rains and 5.14% in the long rains. The stem contained the highest nitrogen content while the roots had the lowest. Phosphate rates did not have significant influence on the yield components except the finger width while the varieties varied significantly (P=.05) on the productive tillers, panicle number, grains per spikelet and the harvest index. Variety U-15 had the highest yield for both seasons with a maximum of 3410 kg ha-1 for the short rains. The newly released variety (U-15) responded well to moderate P supplemented at 25 kg ha-1 P2O5 thus can efficiently utilize N in soils with low N like in Makueni and is highly recommended. The optimal P for the yield and N accumulation was 25 kg ha-1 P2O5 and beyond this point the P would not be translated to profitable yield but a loss to the farmer in the short run.

A geometric model for the periodic undulation of a confined adhesive crack

Inspired by experiments on the instability of confined interfacial cracks, we construct a minimal mathematical model based on symmetry arguments that can reproduce the form of the crack front in a confined domain. We show that the model can be interpreted in terms of the buckling and post-buckling response of a compressed elastica with a nonuniform bending stiffness that is adhered to a linearly elastic substrate. The model has three parameters that allow us to capture the primary wavelength associated with the onset of an undulatory instability of a straight crack front, as well as the finger amplitudes and finger widths in the nonlinear development of the instability. We determine these parameters using an optimization procedure that minimizes the square error between the computed profile and experimental observations. The results of this procedure yield numerical solutions that agree well with the finger profiles experimentally observed in films of different thicknesses. Our approach shows the efficacy of simple models based on symmetry in explaining interfacial instabilities governed by different physical mechanisms.

Non-initial overlap bulk silicon comb-drive actuator with low-voltage and large-displacement

Two different kinds of bulk-Si comb-drive actuators are designed in this work: initial overlap comb-drive actuator and non-initial overlap comb-drive actuator. They are fabricated by a simple post-CMOS bulk micromachining process. A cascade folded beam is designed to achieve large displacement at low driving voltages. And non-initial overlap and unequal wide comb fingers are used to reduce the side instability and improve the pull-in voltage. The measurement results show that the non-initial overlap comb-drive actuator improves the pull-in voltage by 73.3% than the initial overlap comb-drive actuator, and the maximum displacement of the non-initial overlap actuator is larger by 78.9% than that of the initial overlap actuator.

Accuracy of handsv. household measures as portion size estimation aids

Accurate estimation of food portion size is critical in dietary studies. Hands are potentially useful as portion size estimation aids; however, their accuracy has not been tested. The aim of the present study was to test the accuracy of a novel portion size estimation method using the width of the fingers as a 'ruler' to measure the dimensions of foods ('finger width method'), as well as fists and thumb or finger tips. These hand measures were also compared with household measures (cups and spoons). A total of sixty-seven participants (70% female; age 32·7(sd 13·7) years; BMI 23·2(sd 3·5)kg/m(2)) attended a 1·5 h session in which they estimated the portion sizes of forty-two pre-weighed foods and liquids. Hand measurements were used in conjunction with geometric formulas to convert estimations to volumes. Volumes determined with hand and household methods were converted to estimated weights using density factors. Estimated weights were compared with true weights, and the percentage difference from the true weight was used to compare accuracy between the hand and household methods. Of geometrically shaped foods and liquids estimated with the finger width method, 80 % were within ±25% of the true weight of the food, and 13% were within ±10%, in contrast to 29% of those estimated with the household method being within ±25% of the true weight of the food, and 8% being within ±10%. For foods that closely resemble a geometric shape, the finger width method provides a novel and acceptably accurate method of estimating portion size.

Inkjet Printed Interdigitated Conductivity Cells with Low Cell Constant

A novel approach to the fabrication of gold conductive patterns on alumina, silica, glass and polyimide (Kapton) substrates and physical properties of printed interdigitated cells for measuring electrolyte conductance are reported. The process is based on the direct pattering of a gold resinate dissolved in organic solvent by inkjet printing and firing the prints at 400–800°C. The resulting interdigitated electrode devices (16 mm × 52 mm exposed area) consisted of 52 to 9 finger pairs of 240 to 1500 μm wide fingers and spaces, respectively. The sheet resistance of the printed Au layers was around 0.27 Ω on alumina (annealed at 800°C), and 0.86 and 1.18 Ω on glass and Kapton, respectively (annealed at 400°C). The conductivity cell constants of 0.008 to 0.08 cm−1 of the interdigitated devices were found close to theoretically predicted values. Cells with the lowest cell constants are useful for the measurement of electrolytes of low ionic strength, including ultrapure water. Of the three substrates used, alumina has the advantage of withstanding high temperature curing, whereas Kapton features flexibility, and glass transparency.

Numerical investigation of viscous fingering in Hele-Shaw cell with spatially periodic variation of depth

Viscous fingering in a modified Hele-Shaw cell is numerically investigated. The cell allows periodic variation of depth in the lateral direction. The wavenumber n of the depth perturbation has great influence on fingering patterns. For n = 1, the fingering pattern due to the interface instability remains the same as that in the conventional Hele-Shaw cell, while the depth variation causes the steady finger to be a little narrower. For n = 2, four different fingering patterns are captured, similar to the available experimental observations in a modified Hele-Shaw cell containing a centered step-like occlusion. It is found that new fingering patterns appear as n further increases, among which, two patterns with spatial oscillation along both edges of the finger are particularly interesting. One is a symmetric oscillatory finger for n = 3, and the other is an asymmetric one for n = 4. The influence of capillary number on fingering patterns is studied for n = 3 and 4. We find that spatial oscillation of the finger nearly ceases at moderate capillary numbers and occurs again as the capillary number increases further. Meanwhile, the wide finger shifts to the narrow one. It is accompanied by a sudden decrease in the finger width which otherwise decreases continuously as the capillary number increases. The wavenumber and the amplitude of depth perturbation have little effect on the finger width.

Dependence of Impedance Measurement Sensitivity of Cell Growth on Sensing Area of Circular Interdigitated Electrode.

A circular interdigitated electrode (IDE) array for label-free and real-time impedance monitoring of cell growth was fabricated and evaluated. Both the width and spacing of fingers were 50 μm, and the exposed sensing area of the circular IDE was 1.3~3.4 mm. The electrical characteristics of the fabricated circular IDE were modeled as an equivalent circuit, and the values of the circuit parameters extrapolated from the fitting to the measured spectra in different concentrations of NaCl or sensing areas of the circular IDE were analyzed. During cell growth, the resistance of cells extrapolated from the fitting was increased and the maximum rate of change in the real part of the impedance was observed at frequencies of 10 to 22 kHz. The normalized real part of the impedance measured at 10 kHz during cell growth was increased more with decreasing the electrode sensing area, albeit the number of cells to be investigated showed a corresponding increase.

Finger width as a measure of femoral block puncture site: an ultrasonographic anatomical-anthropometric study

Study objectiveFemoral nerve blockade is a regional anesthetic procedure that may be used in prehospital and emergency settings in cases of femoral trauma. Its speed and performance depend on how well the puncture site can be accurately located, something that usually is achieved via visible landmarks and/or by combining various universal preestablished measurements. Most of these methods have been derived from cadaver studies, which often suffer limitations in clinical settings. To facilitate a quick and easy determination of the puncture site, we here attempt to find an in vivo anthropometric measure that closely corresponds to the distance between the femoral artery and femoral nerve. DesignThis is a prospective observational study. PatientsThe study includes 67 patients presenting for elective surgery. MeasurementsThe distance from the femoral nerve to the femoral artery, projected to the skin, was measured by a 13-MHz ultrasonographic linear probe. Anthropometric measurements of the width of the hand fingers were carried out at the distal interphalangeal joints. ResultsThe distance from the femoral artery to the femoral nerve projected to the skin was found to closely correspond to the width of the fifth finger of the dominant hand measured at the distal interphalangeal joint. ConclusionBecause it relies on individual anthropometric information, this finding offers an individualized approach to determining the puncture site in a given patient. We believe that such an approach can improve and simplify femoral nerve blockade procedures in prehospital and emergency settings.

Validity of Inter-rectus Distance Measurement in Postpartum Women Using Extended Field-of-View Ultrasound Imaging Techniques.

Reliability and validity study. To investigate the criterion-related validity and reliability of inter-rectus distance (IRD) measurement using extended field-of-view (FOV) techniques during ultrasound imaging (USI) in parous women. Ultrasound imaging is the gold standard for noninvasive IRD measurement in parous women when investigating diastasis recti; however, its use is limited when IRD is large. Extended FOV techniques (panoramic USI or using acoustic standoff pads) allow complete visualization of the linea alba when the IRD is large and conventional imaging is not sufficient; however, the validity of using these techniques has never been investigated. Two-dimensional ultrasound images were acquired at the superior umbilical border from 21 women using conventional USI, panoramic USI, and a standoff pad. Five images were captured using each method. Inter-rectus distance was measured offline. Criterion-related validity was investigated using repeated-measures analyses of variance to test for bias, and linear regression models, Pearson correlation coefficients (r), and intraclass correlation coefficients (ICCs) to assess agreement. Standard error of the measurement for each extended FOV technique was calculated. The between-trial reliability of each technique was determined using ICCs. Inter-rectus distance from images acquired using extended FOV techniques did not differ from values acquired using conventional USI (P = .441). Images acquired using extended FOV techniques were highly correlated with those acquired using conventional imaging (r>0.95, P<.0001). The standard error of the measurement of each extended FOV technique was 0.17 to 0.18 cm. The between-trial reliability of all techniques was excellent (ICC(3,1)>0.90). Panoramic USI and acoustic standoff pads are valid methods of increasing FOV to measure IRD. In this study, USI measurements were limited to IRDs of less than or equal to 3 finger widths, based on palpation.

Extensive Comparison of Solar Modules Manufactured with Single and Double Printed Cells

With respect to Single Printing (SP), Fine Line Double Printing (FLDP) metallization process delivers 0.21% absolute efficiency gain and 11mg paste saving in mass production. In fact, an average finger width of 47μm is achieved with FLDP, with 16μm line width decrease if compared to SP. In this work we investigate how this cell efficiency gain translates into module power by looking at extensive module production runs at Yingli. FLDP modules use 10% less Ag, have comparable Cell To Module (CTM) loss and reliability performance, and exhibit better Electroluminescence yield due to absence of interruptions.