Universal Correction Factor Research Articles

Determination of the in-plane shear modulus of unidirectional carbon fiber-reinforced plastics using digital image correlation and finite-element analysis

Accurate in-plane shear properties are essential to simulate the mechanical behavior of fiber-reinforced laminated composites. Herein, a digital image correlation technique was used to analyze unidirectional carbon fiber-reinforced composites by three shear-test methods (±45° in-plane, Iosipescu, and V-notched rail shear tests), focusing on the uniformity of shear deformation during each test. The V-notched rail shear test imposed the most uniform shear deformation. This test, however, still imposed non-uniformity around the deformation regime for the in-plane shear modulus calculation, which needed to be accommodated. The non-uniformity was virtually characterized by a combination of various material properties using finite-element analysis. A universal correction factor of 0.925 resolved the non-uniformity involved in the V-notched rail shear test. This enabled the in-plane shear modulus of unidirectional carbon fiber- or glass fiber-reinforced composites to be accurately determined.

Insight into the Evaporation Dynamics of a Pair of Sessile Droplets on a Hydrophobic Substrate.

In this work, we have demonstrated three unique regimes in the evaporation lifecycle of a pair of sessile droplets placed in variable proximity on a hydrophobic substrate. For small separation distance, the droplets undergo asymmetric spatiotemporal evaporation leading to contact angle hysteresis and suppressed vaporization. The reduced evaporation has been attributed quantitatively to the existence of a constrained vapor-rich dome between the two droplets. However, a dynamic decrease in the droplet radius due to solvent removal marks a return to symmetry in terms of evaporation and contact angle. We have described the variation in evaporation flux using a universal correction factor. We have also demonstrated the existence of a critical separation distance beyond which the droplets in the droplet pair do not affect each other. The results are crucial to a plethora of applications ranging from surface patterning to lab-on-a-chip devices.

Walkley-Black Recovery Factor to Reassess Soil Organic Matter: Indo-Gangetic Plains and Black Soil Region of India Case Studies

Maintenance of soil organic carbon (SOC) stock is important for monitoring soil health, which appears to be fragile in view of the reported climatic changes due to global warming in tropical countries such as India. This requires accurate and reproducible measurement of SOC. The wet-digestion technique following the Walkley-Black (WB) method to determine SOC has been used throughout the world in soil science, agronomy, and environmental science laboratories. WB suggested a universal correction factor to convert organic carbon to calculate exact quantity of organic carbon present in soil assuming 77% recovery of SOC. We understand that such a blanket recommendation may not hold well in different bioclimatic systems and for soils representing various depths. We present corrected Walkley-Black recovery factors (WBRFc) for different bioclimates and soil depths in two food-growing zones in India.

Measurement of single leukemia cell's density and mass using optically induced electric field in a microfluidics chip.

We present a method capable of rapidly (∼20 s) determining the density and mass of a single leukemic cell using an optically induced electrokinetics (OEK) platform. Our team had reported recently on a technique that combines sedimentation theory, computer vision, and micro particle manipulation techniques on an OEK microfluidic platform to determine the mass and density of micron-scale entities in a fluidic medium; the mass and density of yeast cells were accurately determined in that prior work. In the work reported in this paper, we further refined the technique by performing significantly more experiments to determine a universal correction factor to Stokes' equation in expressing the drag force on a microparticle as it falls towards an infinite plane. Specifically, a theoretical model for micron-sized spheres settling towards an infinite plane in a microfluidic environment is presented, and which was validated experimentally using five different sizes of micro polystyrene beads. The same sedimentation process was applied to two kinds of leukemic cancer cells with similar sizes in an OEK platform, and their density and mass were determined accordingly. Our tests on mouse lymphocytic leukemia cells (L1210) and human leukemic cells (HL-60) have verified the practical viability of this method. Potentially, this new method provides a new way of measuring the volume, density, and mass of a single cell in an accurate, selective, and repeatable manner.

Comparison of In Vitro-In Vivo Extrapolation of Biliary Clearance Using an Empirical Scaling Factor Versus Transport-Based Scaling Factors in Sandwich-Cultured Rat Hepatocytes

Biliary clearance (CLb ) is often underestimated by in vitro-in vivo extrapolation from sandwich-cultured hepatocytes (SCHs). The objective of this study was to compare the performance of a universal correction factor with transporter-based correction factors in correcting underestimation of CLb . The apparent in vitro CLb of a training set of 21 compounds was determined using the SCH model and extrapolated to apparent in vivo CLb (CLb, app ). A universal correction factor (10.2) was obtained by a linear regression of the predicted CLb, app and observed in vivo CLb of training set compounds and applied to an independent test set (n = 20); the corrected CLb predictions of 13 compounds were within twofold error of observed values. Furthermore, two transporter-based correction factors (Organic anion transporting polypeptides/multidrug-resistance-related protein 2 and diffusion/P-glycoprotein) were estimated by linear regression analysis of training set compounds. The applications of the two correction factors to the test set resulted in improved prediction precision. In conclusion, both the universal correction factor and transporter-based correction factors provided reasonable corrections of CLb values, which are often underestimated by the SCH model. The use of transporter-based correction factors resulted in an even greater improvement of predictions for compounds with intermediate-to-high CLb values.

Extraction of photogenerated charge carriers by linearly increasing voltage in the case of Langevin recombination

Charge extraction by linearly increasing voltage (CELIV) is a powerful and widely used technique for studying charge transport physics, particularly in disordered systems such as organic semiconductors. In this article, we show that CELIV photocurrent transients are strongly dependent on experimental conditions, such as the light intensity and absorption profile. With this in mind, we introduce a universal correction factor that qualitatively extends previously derived CELIV equations, allowing carrier mobility to be estimated at various photogenerated carrier concentrations and, most importantly, photogeneration profiles. In addition, we demonstrate how the CELIV technique can be conveniently used to determine precisely the presence of Langevin bimolecular carrier recombination.

Investigation of swirl meter performance

The performance of vane- and impulse-type swirl meters was investigated, and a direct calibration method for swirl meters was developed. The zero-swirl bias of the meters was tested by installing an axially aligned tube on the swirl meter. Both the vane- and impulse-type meters showed insignificant zero-swirl bias. A known swirl was provided to the swirl meters using an offset, inclined tube arrangement. The angular momentum flux delivered by this system was found to depend linearly on the product of the offset distance and cosine of the inclination angle. Both the impulse- and vane-type meters were found to give measurements below the known swirl value, but both meters gave results that were linearly dependent on the angular momentum flux, which allows characterization of the meter’s efficiency with a single parameter. The efficiency of the impulse-type meter varied from 0.7 to 0.93, was a moderate function of the flow straightener aspect ratio, and depended slightly on the meter size. The vane-type meter’s efficiency was 0.32–0.45 for the conditions tested, was insensitive to the paddle wheel flow straightener aspect ratio, and depended significantly on the meter size. The vane-type meter measurements were also found to depend on the paddle-to-bore-diameter ratio; values slightly exceeding unity should be used. The swirl meter efficiency can be used to correct measurements to an absolute basis. Based on these findings, a universal correction factor does not exist, and a given measuring device will need to be calibrated using the methodology described.

Correction factor for low-loss 180 degrees reflecting linear chirp arrays in SAW devices

Low-loss, 180 degrees -reflecting linear chirps with constant or slowly varying weighting and large time-bandwidth product are analyzed. Multiple reflections are fully taken into account, giving a universal correction factor as a function of array parameters. This should enable such chirps to be designed without making iterations. Surface acoustic-wave (SAW) device layouts making use of the 180 degrees arrays are suggested.

Colony attendance and censusing of Black GuillemotsCepphus gryllein Shetland

The diurnal rhythm of colony attendance by Black Guillemots varied seasonally. No tidal effects were detected but in April attendance was lower when winds exceeded force 4. Numbers were most stable during 05.00–08.00 GMT in the pre-breeding period. Counts at this time and in winds of force 4 or less provide the best estimate of adult populations. Between late March and mid-May, counts of adults associated with breeding habitat account for most birds occupying suitable nest sites and censuses in northern Britain should be conducted in this period. As the proportion of non-breeding adults varies between colonies, no universal correction factor can be used to estimate the number of breeding attempts from counts of birds. Counts aimed at detecting maximum attendance provide greater accuracy than single counts made by flushing all birds on to the sea but take longer. Monitoring units should be stretches o-f coastline that include a number of colonies of different sizes.

A correction method for scattered background intensity of target elements in fluorescent X‐ray spectrometry

AbstractA method for correcting scattered fluorescent X‐ray radiation arising from contaminants in a target of an X‐ray tube is described. The universal correction factor was obtained by measuring the intensity ratio of a characteristic radiation of an analytical element to a background radiation on a reference standard which contains none of the analytical element. The correction was performed by subtracting the intensity ratio of the reference standard from that of a sample. The method requires no calculation of correcting factors.

Theory of Ignition of a Reactive Solid by Constant Energy Flux

Abstract A formula for the ignition time, that Bradley obtained empirically, is derived analytically by a rigorous asymptotic analysis of the limit of large activation energy. Two terms in the expansion must be retained. The second term reveals the existence—just prior to ignition—of a reactive-diffusive zone at the surface of the solid and a transient-diffusive zone in the interior. The analysis also exhibits a universal correction factor for Bradley's formula, of order unity.