Diameter Profile Research Articles

Low-Cost 3D Printer Drawn Optical Microfibers for Smartphone Colorimetric Detection.

A fused deposition modeling (FDM) 3D printer extruder was utilized as a micro-furnace draw tower for the direct fabrication of low-cost optical fibers. An air-clad multimode microfiber was drawn from optically transparent polyethylene terephthalate glycol (PETG) filament. A custom-made spooling collection allows for an automatic variation of fiber diameter between ϕ ∼ 72 to 397 μm by tuning the drawing speed. Microstructure imaging as well as the 3D beam profiling of the transmitted beam in the orthogonal axes was used to show good quality, functioning microfiber fabrication with uniform diameter and identical beam profiles for orthogonal axes. The drawn microfiber was used to demonstrate budget smartphone colorimetric-based absorption measurement to detect the degree of adulteration of olive oils with soybean oil.

Offline and Online Measurement of the Geometries of Train Wheelsets: A Review

Train wheelset is one of the most important and costly-on-maintenance components in the rolling stock. Timely assessment of the wheelset wear can prevent the wheelset wear induced derailment, as well as enable the scheduling of optimal maintenance strategy, like when to perform reprofiling or when to replace, to maximize availability, minimize downtime, and minimize maintenance costs. The geometric parameters of wheelset that need to be constantly measured include wheel diameter and wheel profile. Various measurement methods, from the classical handheld gauges to machine vision-based sophisticated online noncontact vision systems, have emerged for the timely measurement of the geometrics of train wheelsets. Despite the significant development on train wheelset geometrics measurement methods in the past decades, a systematic review is not available yet. In this paper, we systematically review reported gauges and systems for measuring the geometrics of train wheelsets. Forty-six research articles and 13 granted patents published from 1990 to 2022 were reviewed. We provide a categorization of the measurement methods, and then detailly reported the gauges and systems based on offline and online categorization. At the end, the limitations of the state-of-the-art and the research prospects are given.

Clinical Pearls in Postoperative LASIK Management

More than 35 million LASIK procedures have been performed worldwide with reported improvement in outcomes and safety.1 With proper preoperative screening and advanced technology, visual outcomes are excellent with a low complication rate. This paper reviews potential LASIK complications and treatment options. The majority of complications are minor and resolve with treatment without any adverse effects on visual acuity or quality of vision. Over the past 30 years, there have been significant advances in excimer laser technology, which include improved nomograms, flying spot lasers to deliver smoother ablations, accurate trackers, larger optical zones, aspheric curves, and customized treatments that reduce not only refractive errors but other optical aberrations of the eye. In North America, femtosecond lasers for creation of the corneal flap have generally replaced mechanical microkeratomes that require a blade. Advances in femtosecond technology have shown predictable flap thickness and the ability to customize the diameter, location, hinge, and edge profile of the LASIK flap. CE Notification: This article is available as a COPE accredited CE course. You may take this course for 1-hour credit. Read the article and take the qualifying test to earn your credit. Click here to Enroll (https://www.crojournal.com/clinical-pearls-in-postoperative-lasik-management)

Stochastic Method to Predict Effects of Roll Grinding Deviations on Sheet Flatness in Cold Rolling

Abstract Industrial measurements of the diameter profiles of work-rolls used in cold sheet rolling are applied with a stochastic roll-stack model to better understand how residual error from the roll grinding process affects the rolled sheet flatness quality. Roll diameter measurements taken via a noncontact, optical device on new, warm, and worn work-rolls show that the diameter deviations vary along the roll lengths, across roll samples, and at different operational states, suggesting a multidimensional random field problem. Studies are conducted for a 4-high rolling mill with 301 stainless steel sheet to investigate the reliability in achieving target flatness considering the work-roll diameter random field. Also investigated is the sensitivity of the flatness reliability to roll diameter deviations at different locations along the roll lengths and for the three operational states (newly machined, warm, and worn following several passes). The results lead to several key findings. Foremost, it is shown that an assumption of statistical independence among the residual grinding errors at different roll axis locations is improper. Furthermore, it is demonstrated that, for the measured grinding error correlation patterns, the roll diameter deviations external to the roll/sheet contact region play an important role in contributing to flatness defects within the sheet and that these influences vary according to the roll operational state (new, warm, worn). The presented stochastic model and applied measurement data thus provide for a new understanding into how roll grinding performance influences dimensional quality in the sheet rolling process.

Development and Characterization of pH-Dependent Cellulose Acetate Phthalate Nanofibers by Electrospinning Technique.

The aim of this work was to obtain pH-dependent nanofibers with an electrospinning technique as a novel controlled release system for the treatment of periodontal disease (PD). Cellulose acetate phthalate (CAP) was selected as a pH-sensitive and antimicrobial polymer. The NF was optimized according to polymeric dispersion variables, polymer, and drug concentration, and characterized considering morphology, diameter, entrapment efficiency (EE), process efficiency (PE), thermal properties, and release profiles. Two solvent mixtures were tested, and CHX-CAP-NF prepared with acetone/ethanol at 12% w/v of the polymer showed a diameter size of 934 nm, a uniform morphology with 42% of EE, and 55% of PE. Meanwhile, CHX-CAP-NF prepared with acetone/methanol at 11% w/v of polymer had a diameter of 257 nm, discontinuous nanofiber morphology with 32% of EE, and 40% of PE. EE and PE were dependent on the polymer concentration and the drug used in the formulation. Studies of differential scanning calorimetry (DSC) showed that the drug was dispersed in the NF matrix. The release profiles of CHX from CHX-CAP-NF followed Fickian diffusion dependent on time (t0.43−0.45), suggesting a diffusion–erosion process and a matrix behavior. The NF developed could be employed as a novel drug delivery system in PD.

Abstract 9709: Higher Uric Acid To High Density Lipoprotein Cholesterol Ratio Is Associated With Arterial-ventricular Stiffening In Childhood Obesity

Background: Uric acid and high density lipoprotein cholesterol are both considered as risk factors of cardiovascular mortality. The ratio of uric acid to high density lipoprotein cholesterol (UH ratio) has been reported to be a good predictor of cardiovascular events. However, few studies have examined UH ratio and cardiovascular function in overweight/obese children. The purpose of this study is to assess the relationship between UH ratio and cardiovascular function in children. Methods: Echocardiography was performed in 453 children aged 7 to 15 years (body mass index 18 to 34 kg/m 2 ). Stroke volume (SV) was measured using aortic diameter and pulsed Doppler velocity profile. SV was indexed for body surface area (SVI). Effective arterial elastance was estimated by end-systolic pressure/SVI. End-systolic elastance was calculated by a modified single-beat method. Lipids, uric acid, fasting glucose, insulin, homeostasis model assessment for insulin resistance (HOMA-IR), and high sensitive C-reactive protein (hs-CRP) were also assessed. Results: Effective arterial elastance and end-systolic elastance increased significantly with body mass index (r = 0.35 and 0.22, p < 0.01, respectively). There were significant relationships between body mass index and UH ratio, HOMA-IR, high density lipoprotein cholesterol, uric acid, triglycerides, and hs-CRP (r = 0.53, 0.52, -0.32, 0.46, 0.37, and 0.38, p < 0.01, respectively). Effective arterial elastance correlated significantly with UH ratio, HOMA-IR, uric acid, high density lipoprotein cholesterol, triglycerides, and hs-CRP (r = 0.24, 0.20, 0.18, -0.11, 0.21, and 0.18, p < 0.05, respectively). There were significant relationships between end-systolic elastance and UH ratio, HOMA-IR, uric acid, and triglycerides (r = 0.25, 0.16, 0.15, and 0.11, p < 0.05, respectively). In multiple regression analysis, UH ratio was independent determinants of effective arterial elastance and end-systolic elastance. Conclusions: The present study demonstrates that UH ratio is a useful indicator reflecting cardiometabolic risk in obese children. Higher UH ratio and combined arterial-ventricular stiffening may contribute to the increased prevalence of later cardiovascular disorder.

Characterization, Cytotoxicity and Anti-Inflammatory Effect Evaluation of Nanocapsules Containing Nicotine.

(1) Background: Nanotechnology is an emerging field that can be applied in the biomedical area. In this study, Eudragit nanocapsules (NCs) containing nicotine were produced. Nicotine is the main alkaloid found in tobacco and has anti-inflammatory properties. NCs containing nicotine may be used as an adjuvant therapy in the treatment of inflammation in the central nervous system. (2) Methods: Nanocapsules were prepared by the interfacial deposition of the pre-formed polymer method and characterized in terms of zeta potential, diameter, polydispersity index, pH, encapsulation efficiency (EE), stability and sustained release profile. In vitro tests with the PC12 cell line were performed, such as MTT, LIVE/DEAD and ELISA assays, to verify their cytotoxic and anti-inflammatory effects. (3) Results: The nanocapsules presented satisfactory values of the characterization parameters; however, poor encapsulation was obtained for nicotine (8.17% ± 0.47). The in vitro tests showed that the treatment with nanocapsules reduced cell viability, which suggests that the Eudragit or the amount of polymer on top of the cells may be detrimental to them, as the cells were able to survive when treated with bulk nicotine. ELISA showed an increment in the expression of IL-6 and IL-1β, corroborating the hypothesis that NCs were toxic to the cells because of the increase in the levels of these pro-inflammatory cytokines. (4) Conclusions: This study demonstrates that NCs of Eudragit present toxicity. It is therefore necessary to improve NC formulation to obtain better values for the encapsulation efficiency and reduce toxicity of these nanodevices.

Simulation of fixed-bed adsorption column with axial particle diameter profile for removal of solutes at low concentration

Simulation of fixed-bed adsorption column with axial particle diameter profile for removal of solutes at low concentration

Tableted hydrophilic electrospun nanofibers to promote meloxicam dissolution rate

This study investigated the ability of hydrophilic electrospun nanofibers to enhance the dissolution rate of poorly soluble drug Meloxicam (MLX). The drug was loaded into polyvinylpyrrolidone (PVP), polyvinyl caprolactam–polyvinyl acetate–polyethylene glycol (Soluplus®), sodium lauryl sulfate (SLS) nanofibers using electrospinning as fibers fabrication technique. The drug-loaded nanofibers were characterized for their diameter, inter-fibers porosity and drug dissolution profiles, carried out in four different aqueous buffers. Nanofibers loaded with MLX were grinded and used to prepare a solid unit dosage form (Tablets: 7 mm × 4 mm) to facilitate their administration. Fibers nanostructure was characterized through SEM analysis showing a mean diameter in a nanometer size range. Moreover, SEM confirmed the maintenance of fibrous structure within tablets cross section.Dissolutions rate of MLX-loaded nanofibers is improved, compared to free drug, suggesting that nanofibers could be used as suitable carrier to enhance MLX dissolution rate. Moreover, the tablet formulation proposed showed faster release rate in comparison with commercial oral forms (Mobic®) particularly in the dissolution media characterized by lower pHs.

Correlation between Pre-Ovulatory Follicle Diameter and Follicular Fluid Metabolome Profiles in Lactating Beef Cows.

Induced ovulation of small pre-ovulatory follicles reduced pregnancy rates, embryo survival, day seven embryo quality, and successful embryo cleavage in beef cows undergoing fixed-time artificial insemination. RNA-sequencing of oocytes and associated cumulus cells collected from pre-ovulatory follicles 23 h after gonadotropin-releasing hormone (GnRH) administration to induce the pre-ovulatory gonadotropin surge suggested reduced capacity for glucose metabolism in cumulus cells of follicles ≤11.7 mm. We hypothesized that the follicular fluid metabolome influences metabolic capacity of the cumulus-oocyte complex and contributes to reduced embryo cleavage and quality grade observed following induced ovulation of small follicles. Therefore, we performed a study to determine the correlation between pre-ovulatory follicle diameter and follicular fluid metabolome profiles in lactating beef cows (Angus, n = 130). We synchronized the development of a pre-ovulatory follicle and collected the follicular contents approximately 20 h after GnRH administration. We then performed ultra-high performance liquid chromatography—high resolution mass spectrometry (UHPLC-HRMS) metabolomic studies on 43 follicular fluid samples and identified 38 metabolites within pre-ovulatory follicles of increasing size. We detected 18 metabolites with a significant, positive correlation to follicle diameter. Individual and pathway enrichment analysis of significantly correlated metabolites suggest that altered glucose and amino acid metabolism likely contribute to reduced developmental competence of oocytes when small pre-ovulatory follicles undergo induced ovulation.

Size and velocity characteristics of spray droplets in near-region of liquid film breakup in a swirl atomizer

The characteristics of spray droplets resulting from the breakup of liquid film are crucial for the description of the primary atomization process in engine atomizers. The size and velocity characteristics of droplets resulted from the liquid film breakup in a hollow cone swirl atomizer, measured within millimetre distance from the actual location of the liquid film breakup, are analyzed. The radial profiles of the Sauter Mean Diameter (SMD) nondimensionalized with the liquid film thickness for different spray conditions collapse into a single variation trend, and a similar result is obtained for the mean droplet axial velocity nondimensionalized with the streamwise liquid film velocity. The mean axial velocity of the spray droplets measured at the film breakup point is independent of droplet size, which is different from the correlation characteristics of the spray droplets observed in other regions of the spray. The linear film breakup theory overpredicts the SMD of the spray measured at the breakup point significantly, and a scaling law proposed recently for the determination of volume median diameter of the spray captures the experimental trend of the droplet size recorded at the breakup point. The droplet size distribution measured at the breakup point is well described by a Gamma distribution with index parameter n governing the corrugation features of ligaments formed in the film breakup. The chosen value of n = 6.12 is determined experimentally for the sprays from the hollow cone swirl atomizer.

Quality Attributes Comparison of Selected Brands of Rosuvastatin Calcium Tablets Marketed in the US and Bangladesh

Aims: This study investigated whether locally marketed rosuvastatin calcium tablets in Bangladesh have comparable physical and chemical attributes, including in vitro bioequivalence profiles, to the proprietary brand.
 Methodology: Nine generic products (G1-G9) containing 10 mg of rosuvastatin calcium were compared to the proprietary brand Crestor® (R1) and an FDA approved generic rosuvastatin calcium tablet (R2). Weight variation, diameter, thickness, friability, drug content, disintegration time and dissolution profiles were tested according to United States Pharmacopeia (USP) guidelines. In vitro bioequivalence requirements were assessed by calculating difference (f1) and similarity (f2) factors.
 Results: The generic products complied with the pharmacopeial requirements for weight variation, disintegration time and friability. All the tablets had drug ranging between 92%-105% and released more than 80% of rosuvastatin within first 15-30 minutes. However, for brands G5, G7 and G8 the f1 values were 15.7%, 15.82% and 25.21% respectively and their f2 values were 41.8, 41.6 and 32.6 respectively whereas for G9 the f2 value was 43.4. These brands have thus failed to meet in vitro bioequivalence requirements.
 Conclusion: We conclude that few substandard generics of rosuvastatin calcium has somehow found its way to the market and further studies are required to ascertain their noncompliance.

Extension Rate and Bending Instability of Electrospinning Jets: the Role of the Electric Field

Extension rates of an electrospinning jet, in the straight segment as well as in the first jet bend, subjected to different electric fields by changing the tip-to-collector distance (H) at a given applied voltage have been extensively studied through a model solution of poly(N-isopropylacrylamide) in the DMF solvent with a concentration of 17 wt %. Light scattering experiments were carried out to obtain the jet diameter profile along the straight jet (z direction), from which the profiles of the jet velocity vj(z) and the extension rate ε̇(z) (=dvj/dz) were subsequently derived on the assumption of negligible solvent evaporation. In addition, the jet-bending process was also monitored by high-speed video imaging to successfully obtain the axial velocity (z direction) and the lateral velocity of the first bend (wave), from which the extension rate of the first wave was calculated based on a simple equation for the spiral jet. In the straight jet section, the extension rate is found to be the highest at the Taylor cone apex (region I with ε̇I), and it rapidly decays to a relatively constant value in the main jet region (region II with ε̇II), followed by a significant drop to zero near the straight jet end (region III, ε̇III ∼ 0). The presence of the zero extension rate in region III is due to the effective air drag resisting the electric stretching when the fast flowing jet becomes too thin. As the nominal electric field is increased by a smaller H, ε̇II is enhanced. Both ε̇I and ε̇II are higher than the chain retraction rate τe–1 (∼370 s–1) for all the Hs studied, implying that the chain orientation/stretch has already taken place in the straight jet. The residence time of fluid elements in region III is short (<τe), so that the axial elastic strains developed in regions I and II survive downstream in the jet-bending region to stabilize the jet. Our video imaging with high frame rates (>5000 fps) reveals the formation of the “crumpling jet” section at the straight jet end, in which the excitation and relaxation of the dominant Fourier modes of the lateral perturbations of the jet occur in dynamic equilibrium to keep the feature of the straight jet on time average; the lateral perturbations are driven by the compressive force dominantly arising from the air drag (Fdrag). After the conflict between the Coulomb repulsive force (Fc) and the residual elastic tension (Felas), the crumpling jet section finally developed the first bend with a high frequency and a small wavelength, when the section at the jet end slightly shifts downstream. Our results show that both Fdrag and Felas should be taken into consideration at the onset of the jet bending (whipping) process; both promote locally the jet buckling at the straight jet end to generate the crumpling jet, and the latter resists the formation and growth of the first jet bend as well as promotes the shifting of the bending jet upstream. The maximum extension rate of the spiral-growing bend is found to be larger than τe–1. We concluded that the extension rate of the electrospinning jet, from the cone apex to the jet whipping, is position (or time)-dependent, and the process is extremely dynamic due to the fast flow, accompanied by subtle force perturbations along the spinning line.

Horizontal Planar Angular Light Scattering (HPALS) characterization of soot produced in a laminar axisymmetric coflow ethylene diffusion flame

In-flame optical characterization of soot is of vital importance to understand soot formation mechanisms as well as to develop and validate accurate soot models. The present work introduces an unconventional methodology adapted to laminar axisymmetric flames that avoids the issue of variable measurement volume with varying scattering angle in the existing light scattering techniques and thus enables the determination of aggregate size with a higher spatial resolution. Coupled with multi-wavelength line-of-sight attenuation measurements, the proposed Horizontal Planar Angular Light Scattering at 532 nm was found able to provide radial profiles of aggregate size, number and diameter of primary spheres, soot volume fraction, and number density in a laminar axisymmetric coflow ethylene/air diffusion flame established over a Gülder burner. The spatial variation of soot optical properties associated with soot maturity was considered in data analysis.

An empirical model of snowdrift based on field measurements: Profiles of the snow particle size and mass flux

Snowdrift often occurs in cold regions due to the combination of wind and snowfall. The drift formation and movement processes are complex due to the mixture of air, snow and sometimes water as well as the interaction of the temperature, humidity, pressure and flow. To better understand the relevant motion of blowing snow and the vertical snow distribution at an open terrain, the present study creates an empirical model of blowing snow, with the snow particle size and snow flux profile obtained by field measurements in Xinjiang autonomous region in northwest China. Based on the current data, we summarize and analyze the snow particle size probability distribution, the mean equivalent diameter profile and the snow mass flux profile in drifting snow. The results show that the probability distribution of the equivalent diameter of different snow particles (e.g., new snow, deposited snow, and blowing snow) follows the gamma distribution, and these parameters significantly vary for different types of snow particles. The mean equivalent diameter and mass flux of blowing snow considerably decrease with height. The friction velocity is an important factor that affects the profiles of the snow particle size and snow mass flux. The empirical model of the distribution of the particle diameter and mass flux proposed in the present study considering the friction velocity agrees well with field measurements.

Assessing the effectiveness of UHPFRC, FRHSC and ECC against high velocity projectile impact

High velocity projectile impact (HVPI) test was carried out on three classes of cement composites to assess their performance. The tests were conducted on thick block specimens using non-deformable ogive-nosed projectiles with a mass of 250 g and a diameter of 28 mm at approximately 400 m/s. The severity of damage was quantified by the depth of penetration (DOP), equivalent crater diameter (ECD), crater volume (CV), and crater profile (CP). The ability of cement composites to resist the HVPI in terms of DOP seems to be influenced by aggregates because cracks are forced through aggregate at the high strain rate under HVPI. The energy absorption capacity under direct tension is found to be more relevant than flexural toughness in controlling CV and CP. Transient temperature under HVPI is likely elevated to about 250 °C in the ultra-high performance fiber reinforced concrete (UHPFRC), which may lead to higher internal pressure built-up (thus damage) than the engineered cementitious composites (ECC).

Influence of Bulk and Surface Interactions from Thick, Porous, Soil-based Substrates on the Spreading Behavior of Different Viscosity Oils

Crude oils and motor oils are commonly identified in oil spills on land. Controlling and understanding their flow both across and into land is of paramount importance to minimize spread and subsequent damage to the ecosystem. Spreading kinetics and surface energy studies were conducted with these oils over several realistic soil-based matrixes, consisting of topsoil (silt-dominant), sand, clay, and moisture. Spreading area through a 1.3 cm deep matrix was reduced with increased moisture content, densely packed matrixes, and higher viscosity oils. Initial contact angle (CA) measurements for all oils was typically lower on clay matrixes due to its sheet-like structure and high absorption capabilities. Individual droplet penetration took longer at lower MC in direct contradiction to bulk kinetics studies, suggesting different spreading behavior across the surface border. Low viscosity oils recorded the highest lateral spreads, and incomplete wetting profiles were identified for most conditions tested. Importantly, dimensionless profiles of droplet diameter and CA with time did not conform to universal behavior, with statistically significant influences of matrix heterogeneity, oil viscosity, and ill-controlled surface roughness identified. Flow regimes of oil droplets instead conformed to vertical spreading through thick matrixes, and a delayed lateral spreading that occurred quite late into the total penetration time of the droplet. These findings, obtained from studying realistic soil-based matrixes, draws new conclusions regarding the important influences of matrix thickness, variable porosity, and chemical heterogeneity on fluid flow behavior. This new knowledge will assist in the development of future containment efforts surrounding oil spills.

Restitution methodology for space and time dependent solid-fuel port diameter evolution in hybrid rocket engines

A post-processing tool for experimental data is developed to rebuild the instantaneous and local distributions of the fuel port diameter and the fuel regression rate throughout the port conduct during a firing test. The main objective is to use the developed methodology to be able, at a given instant during the firing test, to simulate a hybrid rocket engine configuration and to validate the related numerical modeling. The methodology is based on the coupling between the instantaneous fuel mass flow rate obtained by a ballistic reconstruction technique and the port diameter measurement throughout the port conduct after the firing test. The ballistic reconstruction method is adapted and applied to an experimental hybrid rocket, using hydrogen peroxide/high density polyethlylene propellants, with a catalytic injector (HYCAT). Firstly, a set of representative firing tests is selected from the HYCAT hybrid rocket engine testing campaign. Secondly, an analytical approach leads to instantaneous evolutions of the fuel port diameter and the fuel regression rate profiles throughout the fuel port conduct. The rebuilt profiles of the instantaneous port diameter show the ability of the methodology to restore the space and time distribution of the fuel port diameter. Nevertheless, the fuel regression rate distributions show some limitations of the methodology even though the average is coherent with the ballistic reconstruction trends.

Design of computerized controlled systems for directional laying of engineering communications

The subject of research and development is the technology of directional laying of engineering horizontal inclined wells intended both for exploration drilling and for laying engineering communications by the method of static puncture, as well as installations for their implementation. Laying engineering communications in urban and industrial environments is a common problem, and the existing technologies do not fully meet the increased requirements for the accuracy of working out the specified trajectories and efficiency of wells development. Laying engineering communications through water barriers is a special issue. The proposed method is based on the prompt installation of the forward end of the whipstock barrel in the required position for controlled correction of the trajectory of the well being laid. The main disadvantage of existing methods is the use of only passive trajectory control of the working body and the absence of control systems for the main processes of laying wells. The proposed system includes a guided barrel, a computerized control and management system being the basis for developing a technology for laying directional wells of small diameter and complex profile. The considered technology is the simplest and most economically profitable in comparison with drilling and punching. The possibility of using the described developments including for the purpose of directional drilling has been substantiated.

Abdominal Diameter Profiles Related to Visceral Obesity Based on Lipid Accumulation Product in Obese Adolescent Females

Abdominal Diameter Profiles Related to Visceral Obesity Based on Lipid Accumulation Product in Obese Adolescent Females