Gap Measurements Research Articles

Association of biological age with health outcomes and its modifiable factors.

Identifying the clinical implications and modifiable and unmodifiable factors of aging requires the measurement of biological age (BA) and age gap. Leveraging the biomedical traits involved with physical measures, biochemical assays, genomic data, and cognitive functions from the healthy participants in the UK Biobank, we establish an integrative BA model consisting of multi-dimensional indicators. Accelerated aging (age gap >3.2 years) at baseline is associated incident circulatory diseases, related chronic disorders, all-cause, and cause-specific mortality. We identify 35 modifiable factors for age gap (p < 4.81 × 10-4 ), where pulmonary functions, body mass, hand grip strength, basal metabolic rate, estimated glomerular filtration rate, and C-reactive protein show the most significant associations. Genetic analyses replicate the possible associations between age gap and health-related outcomes and further identify CST3 as an essential gene for biological aging, which is highly expressed in the brain and is associated with immune and metabolic traits. Our study profiles the landscape of biological aging and provides insights into the preventive strategies and therapeutic targets for aging.

The Regional Difference of Womens Age at First Marriage and Pregnancy

This paper researches the regional difference in womens age at first marriage and pregnancy, by examining womens median age at first marriage and womens mean age at first pregnancy. Women and men are divided into four education-level groups to compare the gender gap in each state and indicate the regional pattern. The average difference between women and men is also calculated. Finally, the measures of age, education level, and gender gap are considered together to check the regional overlap. Local birth policies and political stances are also taken into account to understand the situation. The result shows that women living in central states get married and are pregnant at a younger age, and the educational attainment of the population in this region is concentrated in high school and college degrees. The research on the regional difference in birth age and education levels not only helps to improve womens rights and public health, but also provides an angle to understand the effect of policies.

Poverty and inequality impact of COVID‐19 pandemic: The case of Mazar‐i‐Sharif, Balkh province, Afghanistan

AbstractPoverty was already a main problem in Afghanistan even before, but it has exacerbated due to the pandemic. However, the actual impact of the pandemic on households had not been investigated. This study provides such analysis using data obtained from a strictly random survey of 1060 households in the capital of Balkh, the fourth most populated province in Afghanistan. Using headcount ratio and poverty gap measures and both income and expenditure approaches, the results show that an additional 12% of households fell below the poverty line, from an already high of 75% before the pandemic. The poverty gap index rises to 34%, but the computed Gini coefficient indicates no significant change in inequality. Poor governance and corruption in Afghanistan are major impediments to address the issue of poverty. This paper suggests several measures which can be implemented to have effective policies and governance to alleviate poverty.

Assessment of Scapholunate Instability on 4D CT Scans in Patients with Inconclusive Conventional Images.

Background Initial imaging work-up using radiography and CT arthrography sometimes can be insufficient to identify a scapholunate (SL) instability (SLI) in patients suspected of having SL ligament tears. Purpose To determine the diagnostic performance of four-dimensional (4D) CT in the identification of SLI and apply the findings to patients suspected of having SLI and with inconclusive findings on radiographs and CT arthrograms. Materials and Methods This prospective single-center study enrolled participants suspected of having SLI (recent trauma, dorsal pain, positive Watson test results, decreased grip strength) between March 2015 and March 2020. Participants with wrist fractures, substantial joint stiffness, or history of wrist surgery were excluded. Each participant underwent radiography, CT arthrography, and 4D CT on the same day. Participants were divided into three groups: those with no SLI, those with SLI, and those with inconclusive results. SL gap and radioscaphoid and lunocapitate angle were measured using semiautomatic quantitative analysis of 4D CT images by two independent readers. Receiver operating characteristic curves were used to evaluate the diagnostic performance of 4D CT. Thresholds were determined with the Youden index and were applied to the inconclusive group. Results Of the 150 included participants (mean age, 41 years ± 14 [SD]; 102 male, 48 female), there were 63 with no SLI, 48 with SLI, and 39 with inconclusive results. The maximum value and range of SL gap measurements on 4D CT scans showed high sensitivity (83% [40 of 48] and 90% [43 of 48], respectively) and high specificity (95% [59 of 62] and 81% [50 of 62], respectively) in the identification of SLI. At least one of these parameters was abnormal on 4D CT scans in 17 of 39 (44%) participants in the inconclusive group, and 10 of 17 (59%) participants had confirmed SLI. In the 22 participants in the inconclusive group with no indication of SLI at 4D CT, follow-up showed no evidence of SLI in 10 (45%) and enabled confirmation of SLI via arthroscopy in three (14%). Conclusion Scapholunate gap measurements on kinematic 4D CT scans enabled correct identification of SLI in 59% of participants with inconclusive results on conventional images. ClinicalTrials.gov registration no. NCT02401568 © RSNA, 2023 Supplemental material is available for this article. See also the editorial by Demehri and Ibad in this issue.

Annealing Effect on Nickel Oxide Nanoparticles Properties

Abstract: Sodium hydroxide and nickel chloride have been used in the effective chemical precipitation process to create nickel oxide (NiO) NPs. We investigate how the morphological, structural, magnetic, and optical characteristics of nanocrystalline NiO are affected by annealing at temperatures of 300, 400, and 500 °C. Field emission scanning electron microscope (FE-SEM), X-ray diffractometer (XRD), vibrating sample magnetometer (VSM), and ultraviolet-visible (UV-vis) spectrophotometer have been utilized in order to characterize NiO-NPs. XRD pattern indicates the material's excellent crystallinity. At the same time, the FESEM study of the synthesized samples reveals that the annealing temperature has a considerable impact on the films' surface morphology. The average crystallite size of NiO samples falls within the range of 29–30.9 nm., whereas the average grain size of synthesized NiO-NPs, as determined by FESEM images, is between 25 and 29.6 nm. We demonstrate that as the annealing temperature rises, grains’ average size increases, but their shape remains spherical. In addition to that, the UV-Vis spectroscopy analysis shows the particles’ significant absorption peak in the UV region. Our investigation reveals that the synthesized samples have direct band gaps. Before annealing, the energy gap measures 2.4 eV; however, by raising the annealing temperature, we were able to attain a broader range of band gap energies for NiO-NPs, with values spanning between 4.05 and 4.95 eV. The created NiO-NPs demonstrate superparamagnetic behavior, which was found in the VSM results examination. Keywords: Nickel oxide nanoparticles, Annealing, Chemical precipitation, Magnetic properties.

Carbon Nanodots as Complexing Agent in the Formation of Lead(II) Sulfide Thin Films via Direct Deposition of Lead(II) Sulfide Powder

This study reveals for the first time the formation of lead(II) sulfide (PbS) thin films via direct deposition of PbS powder using carbon nanodots (Cdots) as a complexing agent. The chemical bath deposition (CBD) technique was utilized and the Cdots’ mass was varied, i.e., (in g) 3, 5, 7, and 9. The Cdots were prepared from the waste of a rice noodle production home industry via the low-temperature carbonization method. The Cdots were characterized using UV-Vis spectrophotometry, showing absorption peaks at 275 nm and 325 nm; PL, showing an emission peak at 500 nm with cyan luminescence; XRD, showing several peaks, indicating an incomplete carbonization process; FTIR, indicating the existence of C=C, C-H, C-O, and O-H functional groups; HRTEM, revealing the sizes of the Cdots in the range of 2 nm to 6 nm; and SEM, showing a smooth morphology of the Cdots’ surface. The thin films obtained were smooth with higher XRD peaks and better material distribution compared to pure PbS thin film. The band gap measurement indicated that the increase of the PbS band gap was caused by the increase of the Cdots’ mass. Hence, the thin films’ band gap may be tuned using the Cdots’ mass.

Investigation of Antibacterial Activity of Ag-CuO and Ag-ZnO Nanocomposites synthesized by Chemical Precipitation Method

In this present study, the synthesis of Ag-CuO and Ag-ZnO nanocomposites has been conducted. The individual Ag-CuO and Ag-ZnO nanocomposites were synthesized by using chemical precipitation method. The resulting particles were characterized by using UV-Visible, FTIR, XRD and SEM. The optical properties and band gap measurements were explored by UV-Visible spectroscopy. FTIR spectrum of the prepared nanocomposite revealed the presence of vibrational modes which were related to the Cu-O, Zn-O. The XRD analysis confirmed the structural purity of synthesized nanocomposites and the estimated crystallite size is 31.93 nm and 26.62 nm for Ag-CuO and Ag-ZnO nanocomposites respectively. The morphological features were explored by SEM analysis with deposition of Ag nanoparticles on the surface of metal oxide nanoparticles. The antibacterial activities of synthesized nanocomposites were tested on bacteria strains such as Escherichia coli (Gram -ve) and Staphylococcus aureus (Gram +ve) respectively through well diffusion method. The synthesized nanocomposite shows the higher efficacy against E.coli with an average diameter size of 17 mm zone of inhibition. This result suggests that Ag-CuO and Ag-ZnO nanocomposites can be used effectively against microbial growth. Therefore, the synthesized nanocomposite may be promising for the antibacterial agent in pharmaceutical applications.

Synthesis of TiO2 nanotubes from ilmenite with CuS nanoparticles as efficient visible-light photocatalyst.

Titanium dioxide nanotube (TNT) is one of the most widely used photocatalysts. In this research, TNT was prepared by a facile method using ilmenite (FeTiO3) concentrate as the titanium source. For this purpose, iron was leached out from ilmenite using HCl in assistance with the iron powder as the reducing agent to produce pure TiO2, where consequently, TNT was produced through hydrothermal treatment of the prepared TiO2 in an alkaline solution. CuS quantum dots, using the L-cysteine as a linker, were coated on the TNT to improve TNTs' photocatalytic properties. Characterization was done using XRD, SEM, FESEM, HRTEM, FT-IR, nitrogen sorption, and band gap measurement. The results revealed the formation of TNT with a star-shaped macrostructure as well as, a good dispersion of uniform CuS quantum dots with an average diameter of a few nanometers on the TiO2 structure. A dye adsorption kinetics study of the TNT and CuS-dopped TNT showed that TNT carries a higher adsorption capacity compared to the CuS-dopped TNT, developed due to its higher surface area and pore volume. Next, the photocatalytic performance (under visible light) of the prepared composite was studied over the methylene blue (MB) and malachite green (MG) dyes, after the determination of the dye adsorption equilibrium point (where the adsorption stops). TNT showed almost no dye degradation while the prepared composite degraded almost 95 % of the dyes as the result of the reduced band gap from 3.21 to 2.67 eV. In this study, for the first time, the TNT was prepared using a mineral source and ilmenite, enhanced in photocatalytic properties, and presented a successful application.

Evaluating Fiscal Policy Under Cyclical Balance in Developed Countries

Abstract This study investigates the cyclical patterns of fiscal policy rules using various policy variables that respond to the macroeconomic performance of developed countries over the past few decades. The study reveals that regardless of whether the economy is in a recession or a boom, fiscal policy basically displays counter-cyclical behavior. However, the degree of cyclicality varies depending on the output gap measurements chosen and the countries analyzed. Additionally, the estimates using various fiscal policy indicators demonstrate a strong time variation in fiscal cyclical behavior, resulting in a significant increase in the counter-cyclicality of the fiscal balance. The article also applies the time-varying coefficients vector autoregression model to assess the effects of fiscal policy on output and finds that a boost in the cyclically adjusted primary balance positively impacts production in the short run.

An Exploration of the Risk Factors, Severity, and Sequelae of Vocal Fold Hemorrhage in a Population of Voice Patients Before and After Diagnosis

BackgroundVocal fold hemorrhage (VFH) is the rupture (usually acute) of a blood vessel within the true vocal fold. The long-term sequelae of VFH on the mucosal wave (MW) and glottic gap on video stroboscopy remain understudied. The primary objective of this study was to investigate the short-term and long-term consequences of VFH through measured and rated analysis of the mucosal wave and glottic gap. MethodsThe presence of VFH and its extent (limited/moderate vs. extensive VFH) were identified. The primary outcome of this study was mucosal wave, which was assessed on an ordinal scale by three blinded raters pre and posthemorrhage. Only patients who had undergone strobovideolaryngoscopy before sustaining VFH were included. Mucosal wave and glottic gap also were measured using image pixel analysis using the open-access tool, ImageJ (NIH, Bethesda, MD). ResultsTwenty-three subjects were included in this study (mean age 39.78 ± 15.54). Intra-rater reliability for MW ratings was 81.48% ± 6.150% (minimum 77.78%) for all evaluators (κ = 0.519 [0.267–0.772], P < 0.001). Inter-rater reliability analysis revealed 75.56% agreement between evaluators (κ = 0.524 [0.425–0.623], P < 0.001). MWMeasured extrapolated from ImageJ methodology correlated significantly with MWRated (n = 70, r = 0.448, P < 0.001). ΔMWMeasured from baseline to follow-up evaluation were compared for both the initial follow-up visit (FU1) and the second follow-up visit (FU2) [−4.135 ± 31.01 vs. 36.50 ± 39.97, P = 0.025]. Hence, ΔMWMeasured was significantly better by FU2 than FU1, with the larger positive change from baseline representing a greater improvement in the measured mucosal wave. Additionally, there were significant differences in ΔMWRated between those with limited/moderate VFH and those with extensive VFH at FU1. Duration of absolute voice rest correlated significantly with time to VFH resolution. Long-term change in mucosal wave after hemorrhage was assessed using both ΔMWMeasured and MWRated. Based on ΔMWRater, 35.0% of subjects demonstrated ongoing and worse mucosal wave restriction compared to baseline at their most recent follow-up visit. Based on ΔMWMeasured, 50.0% of the subjects showed ongoing and worse mucosal wave restriction compared to baseline at their most recent follow-up visit. ConclusionOverall long-term restrictions in MW after hemorrhage were present in 35.0% of the subjects based on ratings and 50.0% of the patients based on the measured MW using ImageJ, demonstrating the importance of ongoing study into this pathology and how to prevent it, especially in PVU and professional singers. Patients presenting with extensive hemorrhage were at risk for more prominent, detectable changes in mucosal wave compared to those with limited/moderate hemorrhage in the short-term, defined by a mean FU time of 3 months, but not long-term, characterized by a mean FU time 6 months or greater. Whether the severity of VFH is a true indicator of mucosal wave alterations requires additional study, as does the reliability and validity of ImageJ mucosal wave and glottic gap measurement techniques.

Manajemen Risiko Teknologi Informasi Aplikasi E-Office ASN Menggunakan ISO 31000:2018

In carrying out the task of government affairs at Diskominfosanditik Sumedang Regency, an E-Government system is implemented, namely the ASN E-Office application which is a website-based and mobile-based application with a minimum specification of Android 4 which is used by all ASN (State Civil Apparatus) consisting of PNS (Civil Servants) and PPPK (Government Employees with Work Agreements) in Sumedang Regency. With this application, there may be threats and attacks including vulnerabilities that pose a risk, which disrupt the process of using the application. Therefore, the researcher decided to conduct information technology risk management research as a handling and protection of the application by applying the risk management process from ISO 31000:2018 where any information needed in this research was obtained from internal sources at Diskominfosanditik Sumedang Regency. This research was conducted in the informatics section and resulted in 14 possible risks consisting of 3 risks with high levels, 2 risks with medium levels, and 9 risks with low levels. From the GAP measurement, there is a difference that the need for risk measurement as the first step for risk management.&#x0D;

Intra- and inter-observer agreement in distal radius fracture dislocation measurement of casting position.

Most displaced distal radius fractures (DRF) are treated nonoperatively, with reduction and immobilization in a cast. Studies assessing intra- or inter-observer agreement on radiologic measurements of casting position have not been published, which was the aim of our study. Our study is based on the Kuopio Osteoporosis Risk Factor and Prevention (OSTPRE) study. All detected DRFs during the OSTPRE follow-up were retrieved and based on sample size calculations 50 fractures were randomly selected for the study. 5 independent reviewers measured dislocation parameters and wrist position in a cast from the radiographs. A linear mixed model was used to estimate the concordance correlation coefficient (CCC) and total deviance index (TDI) that were used to evaluate intra- and inter-observer agreement. We used Kappa values to determine intra- and inter-rater agreement on radiographically acceptable reduction of the DRF. Limits of acceptable position were those defined by Finnish Current Care Guidelines. For radial inclination, radial shortening, and dorsal/volar tilt, intra- and inter-observer correlations were high (CCC > 0.76). In addition, measurements of wrist angle in a splint had high correlations (CCC > 0.78), whereas measurement of intra-articular gap and step had poor correlations (CCC < 0.52). The Kappa value for overall agreement on the radiographically acceptable position of the DRF was modest (0.59). Intra- and inter-observer repeatability of casting position of radial inclination, radial shortening, and dorsal/volar tilt were high whereas intra-articular gap and step had poor correlations.

A 4-Week Straw Phonation in Water Exercise Program for Aging-Related Vocal Fold Atrophy.

This study evaluated the efficacy of a 4-week straw phonation in water (SPW) exercise program on aging-related vocal fold atrophy (VFA), with a secondary objective to examine the immediate effects of SPW exercises. Thirty-eight older adults aged 60 years and above formally diagnosed with aging-related VFA were randomly assigned into an experimental group undergoing SPW exercises with an 8-cm depth of straw submersion into water for 4 weeks plus vocal hygiene practice (n = 20), and a control group with only vocal hygiene practice (n = 18). Outcome measures included laryngeal endoscopic measures of glottal gap, auditory-perceptual ratings of voice quality, acoustic measures, aerodynamic measures, and standardized self-assessment questionnaire scores. An additional round of acoustic and aerodynamic assessment following 20 min of SPW exercises was conducted to examine the immediate effects. Significant improvements in normalized glottal gap area, perceptual rating of breathiness, smoothed cepstral peak prominence, harmonics-to-noise ratio (HNR), mean oral airflow, subglottal pressure and laryngeal airway resistance at comfortable loudness, Voice-related Quality of Life scores, and Chinese Vocal Fatigue Index Factor 3 scores were observed in the experimental group relative to the control group. There were also significant immediate effects for HNR, mean oral airflow, subglottal pressure, and laryngeal airway resistance. These findings suggested significant immediate improvements in vocal function following SPW exercises, with additional significant improvements in vocal function as well as significant improvements in quality of life following the 4-week SPW exercise program. Further studies with more long-term follow-up are recommended to better understand the efficacy of SPW exercises with deep levels of straw submersion into water as an effective clinical option for the management of hypofunctional dysphonia associated with aging-related VFA.

Income Inequality and Political Trust: Do Fairness Perceptions Matter?

Political trust—in terms of trust in political institutions—is an important precondition for the functioning and stability of democracy. One widely studied determinant of political trust is income inequality. While the empirical finding that societies with lower levels of income inequality have higher levels of trust is well established, the exact ways in which income inequality affects political trust remain unclear. Past research has shown that individuals oftentimes have biased perceptions of inequality. Considering potentially biased inequality perceptions, I argue that individuals compare their perceptions of inequality to their preference for inequality. If they identify a gap between what they perceive and what they prefer (= fairness gap), they consider their attitudes towards inequality unrepresented. This, in turn, reduces trust in political institutions. Using three waves of the ESS and the ISSP in a cross-country perspective, I find that (1) perceiving a larger fairness gap is associated with lower levels of political trust; (2) the fairness gap mediates the link between actual inequality and political trust; and (3) disaggregating the fairness gap measure, political trust is more strongly linked to variation in inequality perceptions than to variation in inequality preferences. This indicates that inequality perceptions are an important factor shaping trust into political institutions.

A facile two-step hydrothermal preparation of 2D/2D heterostructure of Bi2WO6/WS2 for the efficient photodegradation of methylene blue under sunlight

A facile two-step hydrothermal method was successfully used to prepare a photocatalyst Bi2WO6/WS2 heterojunction for methyl blue (MB) photodegradation. Fabricated photocatalysts were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS). Band gap measurements were carried out by diffuse reflectance spectroscopy (DRS). Results indicated that the prepared heterostructure photocatalyst has increased visible light absorption. Photocatalytic performance was evaluated under sunlight irradiation for methylene blue (MB) degradation as a model dye. Variations in pH (4–10), amount of catalyst (0.025–0.1 g/L), and initial MB concentrations (5–20 ppm) were carried out, whereas all prepared catalysts were used to conduct the tests with a visible spectrophotometer. Degradation activity improved with the pH increase; the optimum pH was approximately 8. Catalyst concentration is directly related to degradation efficiency and reached 93.56% with 0.075 g of the catalyst. Among tested catalysts, 0.01 Bi2WO6/WS2 has exhibited the highest activity and a degradation efficiency of 99.0% in 40 min (min) for MB. MB photodegradation follows pseudo-first-order kinetics, and obtained values of kapp were 0.0482 min−1, 0.0337 min−1, 0.0205 min−1, and 0.0087 min−1 for initial concentrations of 5 ppm, 10 ppm, 15 ppm, and 20 ppm, respectively. The catalyst was reused for six cycles with a negligible decrease in the degradation activity. Heterostructure 0.01 Bi2WO6/WS2 has exhibited a photocurrent density of 16 μA cm−2, significantly higher than 2.0 and 4.5 μA cm−2 for the pristine WS2 and Bi2WO6, respectively. The findings from these investigations may serve as a crucial stepping stone towards the remediation of polluted water facilitated by implementing such highly efficient photocatalysts.

Revising the Racial Wage Gap Among Men in the United States: The Role of Nonemployment, Underemployment, and Incarceration

This article examines trends in racial earnings disparities to observe how the socially constructed concept of race impacts the U.S. labor market for men from 1981 to 2008. I develop a racial earnings gap measure that accounts for the labor market experience of the nonemployed using Survey of Income and Program Participation (SIPP) Completed Gold Standard data produced by the U.S. Census Bureau. This data set includes administrative earnings data from the Internal Revenue Service and the Social Security Administration merged with SIPP household survey data. Conventional measures that do not account for the nonemployed miss the impact of an increasing number of nonemployed, prime working-age men, particularly Black men, and the accelerating incarceration rate during the 1980s-1990s. An unadjusted estimate of the White earnings premium indicates a large racial earnings gap that fluctuates between about 140% and 150% over 1981-2008. This suggests that labor market conditions and policies may be limiting, but not reducing, racial earnings inequality. The adjusted White earnings premium averages 28 percentage points higher over the time period of this study. The premium also rises further, more quickly, and sustains this higher level longer. The adjusted measure suggests that labor market conditions and policies continue to produce growing levels of racial earnings inequality.

Ultrasound examination of the pelvic floor during active labor: A longitudinal cohort study.

There is limited evidence about changes in the pelvic floor during active labor. We aimed to investigate changes in hiatal dimensions during the active first stage of labor and associations with fetal descent and head position. We conducted a longitudinal, prospective cohort study at the National University Hospital of Iceland, from 2016 to 2018. Nulliparous women with spontaneous onset of labor, a single fetus in cephalic presentation, and gestational age ≥37 weeks were eligible. Fetal position was assessed with transabdominal ultrasound and fetal descent was measured with transperineal ultrasound. Three-dimensional volumes were acquired from transperineal scanning at the start of the active phase of labor and in late first stage or early second stage. The largest transverse hiatal diameter was measured in the plane of minimal hiatal dimensions. The levator urethral gap was measured as the distance between the center of the urethra and the levator insertion using tomographic ultrasound imaging. Measurements of the levator urethral gap were made in the plane of minimal hiatal dimensions and 2.5 and 5 mm cranial to this. The final study population comprised 78 women. The mean transverse hiatal diameter increased 12.4% between the two examinations, from 39.4 ± 4.1 mm (±standard deviation) at the first examination to 44.3 ± 5.8 mm at the last examination (p < 0.01). We found a moderate correlation between the transverse hiatal diameter and fetal station at the last examination (r = 0.44, r2 = 0.19; p < 0.01; regression equation y = 2.71 + 0.014x), and a weak correlation between the change in transverse hiatal diameter and change in fetal station (r = 0.29; r2 = 0.08; p = 0.01; regression equation y = 0.24 + 0.012x). Levator urethral gap increased significantly in all three planes on both the left and right sides. Head position was not associated with hiatal measurements after adjusting for fetal station. We found a significant, but only modest, increase of the hiatal dimensions during the first stage of labor. The risk of levator ani trauma will therefore be low during this stage. The change in transverse hiatal diameter was associated with fetal descent but not with head position.

A model for critical current effects in point-contact Andreev-reflection spectroscopy

It is well known that point-contact Andreev-reflection spectroscopy provides reliable measurements of the energy gap(s) in a superconductor when the contact is in the ballistic or diffusive regime. However, especially when the mean free path of the material under study is small, obtaining ballistic contacts can be a major challenge. One of the signatures of a Maxwell contribution to the contact resistance R is the presence of “dips” in the differential conductance, associated with the sudden appearance of a Maxwell term, in turn, due to the attainment of the critical current of the material in the contact region. Here we show that using a proper model for the R(I) of the material under study, it is possible to fit the experimental curves (without the need of normalization) obtaining the correct values of the gap amplitudes even in the presence of such dips, as well as the temperature dependence of the critical current in the contact. We present a test of the procedure in the case of Andreev-reflection spectra in Mg0.85Al0.15B2 single crystals.

Marginal and Internal Gaps, Surface Roughness and Fracture Resistance of Provisional Crowns Fabricated With 3D Printing and Milling Systems.

To compare the marginal and internal gap, surface roughness, fracture resistance and mode of failure of provisional crowns fabricated with 3D printing and CAD/CAM manufacturing techniques. A maxillary first premolar was prepared for an all-ceramic crown and reproduced in cobalt-chromium metal dies (n=30) following CAD/CAM technology. The die was digitally scanned and exocad software was used to design the missing crown, which was manufactured using a CAM milling machine and two types of 3D printing machines (SLA and DLP) to produce 10 provisional crowns per group. The crowns were cemented to their respective dies and stored in water (24 hours; 37°C) followed by 600 thermal cycles (5°C/55°C) and 100,000 mechanical cycles (at 50N). Marginal and internal gap measurements were carried out using a 3D superimposition technique. Surface roughness (Ra) was determined using a profilometer at 0.5 mm/second cross-head speed. The crowns were loaded to fracture at 0.5 mm/minute cross-head speed. Fracture forces and mode of failure were recorded, and data were analyzed using one-way analysis of variance (ANOVA) and multiple comparisons post hoc tests (p<0.05). The SLA group exhibited higher marginal and internal gaps than both the CAD/CAM and DLP groups (p<0.05). The DLP group showed higher surface roughness than the CAD/CAM and SLA groups (p<0.01). The CAD/CAM and SLA groups showed higher resistance to fracture than the DLP (p<0.05) group. Mode of failure I: Minimal crown fracture or crack, was predominate among DLP and SLA crowns (60%), while the Mode II: Less than half of the crown lost, was predominant among CAD/CAM crowns (60%). Crowns manufactured following CAD/CAM technique have better marginal and internal fit, surface roughness than SLA and DLP crowns. The CAD/CAM and SLA crowns showed higher resistance to fracture than the DLP crowns.

Rail Joint Gap Measurement Method using Train Frontal Images Captured by a Handy Video Camcorder

Joint gap measurement is an important inspection to prevent buckling of railways. However, this measurement is labor intensive and time consuming because the tracks are too long for manual inspections. Therefore, we have developed a rail joint gap measurement method using train frontal images recorded by a handy video camcorder. In this paper, we describe details pertaining to the proposed method and discuss the measurement results obtained based on an experiment involving a commercial train.