Minor Diameter Research Articles

KARAKTERISTIK PEMANEN DAYA LISTRIK BERBASIS GETARAN STRUKTUR

Mechanical vibration is a potential source of micro-electrical energy harvesting mechanisms for micro electrical power supply for IoT system networks, wireless and sensors where the power requirements are relatively lower and available independently. In this study, the characteristics of the cylinder vibration response as a trigger for energy harvesting from flow-induced vibrations at various air velocities were investigated experimentally in a wind tunnel test section. Harvesting of micro power from cylinder’s motion by using galfenol (Fe-Ga) material was also investigated simultaneously. The maximum cylinder’s vibration response was obtained by using the plain cylinder model. Cylinder taper variation reduce the maximum vibration response. The position of the major (D) and minor (d) (or inverse position) diameters also affects the vibration response. However, tapering the cylinder reduces the onset vibration with respect to the flow velocity. The frequency of the vortex (Strouhal, St) ranges from 0.25 to 0.12. The minor diameter of the tapered cylinder has the effect on decreasing the vibration response and tends to be stationary. Minor diameter reduction reduces the potential for vibration to the structure. The maximum power generated by the test model is about 8.5 mW with the power RMS value of 2.3 mW and power coefficient about 4%.

Palynomorphometry in ferns: Ctenitis (Dryopteridaceae), a case of study in the Southern Cone of America

Abstract The morphometric knowledge about the spores of the Ctenitis has not yet been deepened. Considering the folded spores of this genus which inhabit the Southern Cone of America the aims were to increase infrageneric knowledge, to evaluate the relationship among the morphometric characters of the folded spores in these Ctenitis species and to verify the spore’s morphometry as a taxonomic tool. This study was performed with herbarium material. The spores were analyzed with light microscopy (LM) and scanning electron microscopy (SEM). The variables analyzed were: major and minor equatorial diameter, polar diameter, length of the laesura and length, width and height of the folds. The test chosen to analyze the study variables was ANOVA. Four spore sets are proposed. The “elongate-type” is made up of C. aspidioides and C. nervata. The “medium-type” is made up of C. anniesii, C. distans, C. falciculata and C. paranaensis. The “handle shape-type” is represented by C. bigarellae, C. eriocaulis and C. submarginalis. Finally, the “short-type”, consists only of C. deflexa. The morphometric data of spores together with the statistical analysis provided useful information for the distinction of some Ctenitis species studied in the Southern Cone of America. These results contribute to the studies aeropalynologycal and palaeopalynological.

Physical and engineering properties of chickpea (Cicer arietnum L.) for planter design

The design of a chickpea planter and its optimum performance requires physical and engineering properties of the grain varying with cultivars. Such properties include size, shape, mass, density, static friction coefficient, and repose angle etc. The cultivars viz. JG 16, HC 5, KWR 108, IPC 4-1, IPC 5-62, DCP 92-3, IPC 4-98 and JG 14 were investigated at 11.0±1.0 per cent moisture content using standard methodology. The grain size was presented in terms of major, intermediate, minor, and geometric mean diameters as 8.49-9.78, 5.91-7.23, 5.88-6.94, and 6.68-7.89 mm, respectively. The shape of the grain was presented in terms of sphericity which ranged from 0.78-0.81. The thousand seed mass, bulk density, and true density were 198-338 g, 830-880 kg m-3, and 1310-1350 kg m-3, respectively. The static friction coefficient was the least against aluminium followed by galvanised iron and mild steel surfaces with respective ranges of 0.37-0.40, 0.41-0.45, and 0.52-0.56. The angle of repose ranged from 26.4-27.7 degrees. There was a significant varietal difference in different physical and engineering properties of chickpeas except true density and angle of repose, where the difference was non-significant.

Morfologia e morfometria de Paratanaisia bragai () Freitas, 1959 (Digenea, Eucotylidae) através da microscopia de luz e microscopiaeletrônica de varredura

Paratanaisia bragai is a digenetic trematode that reaches sexual maturity in the kidney collecting ducts of domestic and wild birds, while the snails Subulina octona and Leptinaria unilamellata serve as its intermediate hosts in Brazil. The present study analyzed the morphology and morphometry of P. bragai. Adult specimens of the parasite were collected from naturally infected Columba livia kidneys, fixed and prepared for observation via bright field and differential interference contrast light microscopy and scanning electron microscopy. The parasite has an elongated and flattened body, with a subterminal oral sucker located at the anterior end of the body, as observed by all techniques used. Staining the parasite with hematoxylin-eosin enabled observation of the pharynx, located posteriorly to the oral sucker, the vitelline glands, which are extra-cecal and extend anteriorly to the pre-ovarian region and later to the median region of the body, and intestinal caeca parallel to the vitelline glands. The presence and functionality of the acetabulum are controversial points in the literature, but it was observed in all specimens analyzed by scanning electron microscopy, with a major diameter of 38.36 ± 6.96 (28.77 - 45.39) and minor diameter of 31.59 ± 7.04 (21.75 - 38.16). Close to the acetabulum, scales were observed in the integument of the parasite. Scales with (1 - 5) blade divisions were identified. In the genital pore, it was possible to see the everted cirrus with rosette shape. The excretory pore (first morphometric record) is dorsal and subterminal, with major diameter of 12.27 ± 9.16 (5.79 - 18.75) and minor diameter of 3.95 ± 1.49 (2.89 - 5.00).

EFFECTS OF MOISTURE CONTENT ON PHYSICAL PROPERTIES OF PADDY AND DEHUSKED RICE

The physical properties of rice are among the most important parameters for design of agricultural machine and other equipment for handling, planting, harvesting, processing, packaging and storing. This work is aimed at the determination of some of the physical properties of two varieties of rice at varying moisture content that are important in designing rice handling machine. The physical properties of two most popular produced rice varieties in Nigeria (FARO 44 and FARO 57) both paddy and dehusked at three different moisture content (5, 10 and 15%) were determined. Laboratory studies were carried out to determined physical properties of the two varieties of rice ((FARO 44 and FARO 57) important properties for the laboratory work includes: bulk density, unit density, roundness, axial dimensions, sphericity, projected areas, unit volume, unit weight, apparent density, were determined based on different moisture content and random sampling techniques. The results showed that minimum lengths of dehusked rice ranged from 4.57 - 5.29 mm while maximum lengths were between 8.21 - 8.25 mm. For paddy these lengths were minimally 7.65 - 8.78 mm and maximum lengths were 11.39 mm. The least range of minor diameters of dehusked rice was 4.57 - 5.29 mm and maximally these were 8.21 - 8.25 mm. Intermediate diameters were minimally 1.43 mm and maximally in the range of 2.71 - 2.78 mm for dehusked rice; for paddy these were 1.65 - 1.76 mm and 2.46 - 2.78 mm, respectively. Geometric mean diameters ranged between 3.31 - 4.05 mm. For paddy, projected area obtained within the range of 11.71 - 29.75 mm 2. For dehusked rice, projected area obtained in the range of 8.79 - 21.19 mm 2. Estimates of roundness were not higher than 33.6% for paddy or 54% for some grains of dehusked rice. The grains appeared more spherical than they were round since paddy were 35.3 - 48.3% spherical while dehusked grains were 39.8 - 59.4% spherical. Bulk densities ranged between 531.0 - 553.8 kg/m 3 and 839.6 - 852.7 kg/m 3 for dehusked forms of Faro 44 and Faro 57, respectively. True density was in the range of 1071.6 - 1566.2 kg/m 3.This study concludes that moisture content and variety affect the engineering property and is useful in the design, development of machine for processing and handling of rice products.

Multi-chord observation of stellar occultation by the near-Earth asteroid (3200) Phaethon on 2021 October 3 (UTC) with very high accuracy

Abstract We observed a stellar occultation by (3200) Phaethon, which occurred in western Japan on 2021 October 3 (UTC). This observation was requested by the DESTINY+ mission team, which plans to conduct a flyby of asteroid Phaethon in 2028. Overall, this research effort contributes towards a large-scale observation campaign with a total of 72 observers observing from western Japan to southern Korea. 36 stations were established, and stellar occultation by the asteroid Phaethon was detected in 18 of them. This is the first time that this many multiple chord observations have been made for such a small asteroid (it has a diameter of 5–6 km). Observational reductions show that the apparent cross-section of Phaethon at the time of the occultation could be approximated using an ellipse with a major diameter of 6.12 ± 0.07 km and a minor diameter of 4.14 ± 0.07 km, and a position angle of 117.°4 ± 1.°5. As can be seen from the small error bars of the fitted ellipse, we have succeeded in estimating the shape and size of the asteroid with an extremely high degree of accuracy. Our observation results, together with other observations, will be used to create a 3D model of Phaethon and to improve its orbit. The instruments that we used for this observation are commonly used by many amateur astronomers in Japan for occultation observations and are not difficult to obtain. This paper describes the method and results of our observations using a CMOS camera and a GPS module, so that many people can participate in occultation observations in the future.

Electrohydrodynamic (EHD) effects on condensation heat transfer of R-11 on circular and elliptical cylinders: An experimental study

In the current experimental research, electrohydrodynamic (EHD) assisted condensation heat transfer of R-11 on a horizontal cylinder is studied for two different cases of circular and elliptical cross sections. Experiments are carried out for different various tilting angles of the elliptical cylinder. Furthermore, effects the involving parameters such as electric voltage, electrode-cylinder distance, and imposed evaporative heat flux are investigated. A separate set of complementary experiments is also conducted to visualize the EHD influence on instability of the condensate liquid surface. The electric field effects are shown to start at a specific voltage depending on the electrode-cylinder distance. Passing the onset of EHD initiation point, slight increase of the condensation heat transfer at low voltages is followed by a significant rise at elevated voltages until the electric discharge takes place. It is shown that increasing the electrode-cylinder distance causes the reduction of the heat transfer rate due to the weakened electric field. However, it delays the electric discharge and thus extends the maximum possible heat transfer enhancement. Results also indicate that the condensation heat transfer on the elliptical cylinder inversely depends on the angle between the minor diameter and horizontal direction. The elliptical cylinder generally facilitates the separation and falling of the condensate film thus leads to a maximum of 24% higher heat transfer enhancement compared to the circular cylinder. Moreover, visual observations of the condensation process reveal that thinning and disturbance of the liquid condensate film change of the film to pseudo-dropwise condensation are the two main possible mechanisms responsible for the heat transfer enhancement under the applied electric field. The maximum heat transfer enhancement values of 3.17 and 3.36 are obtained at electrode voltage of V = 24 kV, for circular and elliptical cylinders respectively.

Discriminant Canonical Analysis as a tool to determine traces of endangered native hen breed introgression through egg hatchability phenomics.

The main objective of this study was to develop a pipeline to detect phenogenomic introgression across different multivariety breeds and to validate such classification focusing on external egg and hatchability-related traits using a discriminant canonical analysis approach. For this, 1368 eggs belonging a flock of 94 endangered Spanish autochthonous breed breeding hens (Andalusian Tufted, Blue Andalusian, Spanish White-Faced, and Utrerana) and a control outgroup comprising 32 eggs belonging to 4 Araucana hens were considered. Multicollinearity analysis of hatchability-related traits revealed embryonic mortality, embryonic mortality in the second stage of incubation, viable hatching chick, major diameter, and minor diameter should be discarded from the analysis (VIF≤5) given they did not significantly contribute to variability explanation potential of the discriminant model. A stepwise discriminant canonical analysis was developed and egg weight, shape index, hatchability, and fertility variables reported the highest discriminant power (Wilks' Lambda values of 0.7861, 0.7871, 0.8076, and 0.9457, respectively). The first two functions explained 85.25% intergroup variability. Interbreed and varieties proximity was evaluated using Mahalanobis distances representation and data mining cross-validation allowed to detect genetic introgression between different genotypes. Easily collectable traits as egg weight and shape index must be considered for the development of breeding programs as a measure to ensure breed protection. The model may be translatable to other endangered breeds to optimize avian breeds conservation plans worldwide.

Large eddy simulation of temperature-variation effect of impinging planar lobed synthetic jet on flat plate and the semi-cylindrical concave plate

Temperature-variation becomes increasingly evident when an impinging synthetic jet is restricted and confined excessively by the target plate. However, the confinement effect of the target plate on the temperature-variation effect during impinging heat transfer by a synthetic jet has not been clarified. In this study, impinging heat transfer by a synthetic jet induced by a planar lobed orifice on a flat plate and a semi-cylindrical concave plate is investigated by means of Large Eddy Simulation. The planar lobed synthetic jet is characterized by the geometry of the lobed nozzle, and the velocity along its major diameter is larger than that along its minor diameter. As the mainstream jet moves downstream, the difference between the major and minor diameters decreases gradually. At dimensionless jet-to-surface distance of H/d = 8, the flow field attached to the flat plate along the major diameter is similar to that along the minor diameter. The results show that two types of mechanisms have induced the temperature-variation. For the flat plate, its temperature-variation comes from the suction of the wall jet near the stagnation region confined by the target plate, which becomes more conspicuous particularly at small dimensionless jet-to-surface distance. By contrast, the temperature-variation is less conspicuous at large dimensionless jet-to-surface distance because the inhaling region is distant from the target plate. For the concave plate, its temperature-variation is due to the large recirculation zone along the curvilinear direction. During the suction process of the cycle, the heated wall jet attached to the plate surface is re-inhaled into the cavity through the large recirculation zone, and the temperature of the air inside the cavity increases. During the ejection process of the cycle, the wall jet is entrapped into the jet mainstream and then returns to the target plate. Correspondingly, the mean velocity of the wall jet and the wall shear stress of the target plate are less than those of the flat plate. Time and frequency analyses had revealed the characteristics of inherent aggressive pulsation inside the planar lobed synthetic jet. The velocity in the primary frequency dominates the planar lobed synthetic jet, whereas higher-order velocities are negligible.

Characterizing nuclear morphology and expression of eNOS in vascular endothelial cells subjected to a continuous range of wall shear stress magnitudes and directionality

Complex patterns of hemodynamic wall shear stress occur in regions of arterial branching and curvature. Areas within these regions can be highly susceptible to atherosclerosis. Although many studies have characterized the response of vascular endothelial cells to shear stress in a categorical manner, our study herein addresses the need of characterizing endothelial behaviors over a continuous range of shear stress conditions that reflect the extensive variations seen in the vasculature. We evaluated the response of human umbilical vein endothelial cell monolayers to orbital flow at 120, 250, and 350 revolutions per minute (RPM) for 24 and 72 h. The orbital shaker model uniquely provides a continuous range of shear stress conditions from low and multidirectional at the center of each well of a culture plate to high and unidirectional at the periphery. We found distinct patterns of endothelial nuclear area, nuclear major and minor diameters, nuclear aspect ratio, and expression of endothelial nitric oxide synthase over this range of shear conditions and relationships were fit with linear and, where appropriate, power functions. Nuclear area was particularly sensitive with increases in the low and multidirectional WSS region that incrementally decreased as WSS became higher in magnitude and more unidirectional over the radius of the cell layers. The patterns of all endothelial behaviors exhibited high correlations (positive and negative) with metrics of shear stress magnitude and directionality that have been shown to strongly associate with atherosclerosis. Our findings demonstrate the exquisite sensitivity of these endothelial behaviors to incremental changes in shear stress magnitude and directionality, and provide critical quantitation of these relationships for predicting the susceptibility of an arterial segment to diseases such as atherosclerosis, particularly within complex flow environments in the vasculature such as around bifurcations.

Automatic Measurement of External Thread at the End of Sucker Rod Based on Machine Vision.

Aiming at the low efficiency of manual measurement of threads and the lack of practicability in machine vision measurement before, online size measurement of threads at the end of sucker rods based on machine vision was studied. A robotic arm is used to carry an optical device to achieve high-quality image acquisition of threads. Based on the prior knowledge of the thread profile angle, the directional edge detection operator is customized to achieve the accurate detection of the left and right edges of the thread. Noise filtering, sorting, and left and right edge-matching algorithms based on connected domains are developed to eliminate the interference effects of electrostatic dust and oil pollution in online measurement, and the dimension of thread profile angles, pitches, major diameters, and minor diameters can be precisely calculated. The experimental results show that the screw thread parameter measurement time is about 0.13 s; the maximum and minimum average errors of the thread angles are 0.011° and 0.632°, respectively; and the total average deviation is less than 0.08°. For the screw thread pitch, major diameter, minor diameter, and pitch diameter parameter measurement, the deviation of the measurement results between the proposed method and the universal tool microscope (UTM) method is less than 10 μm. It fully proves the effectiveness and accuracy of the method in this paper and, at the same time, shows that the method has good real-time performance and high application significance, which lays a good foundation for the subsequent online thread measurement.

Tricuspid annulus deformation indices predicting severe functional tricuspid regurgitation: 3D echocardiographic study

Abstract Introduction In these past few years tricuspid valve (TV) got its appreciation due to the latest focus of complications driven by tricuspid regurgitation (TR). Even though severe TR may require surgical repair, precise analyses performed by 3D echocardiographic tools to determine severe functional TR (FTR) are scarce. Aim To determine the accuracy of 3D echo-derived TV parameters in predicting severe FTR. Methods Prospective observational cohort study enrolled 90 patients (pts) with functional moderate (70%) or severe (30%) TR. Pts with FTR of various aetiologies (due to left-sided valvular heart disease, pulmonary arterial hypertension [invasively measured pulmonary capillary wedge pressure <15 mmHg]) were included in this study. Pts with ischemic heart disease (assessed by coronary angiography) were excluded from the analysis. TR severity was measured quantitatively: severe FTR was defined by 2 parameters: vena contracta ≥7 mm and TR effective regurgitant orifice area ≥40 mm2. The transthoracic echocardiography was performed and included the following 2D and 3D-derived TV parameters: the systolic and diastolic 4-chambers (septal – lateral), 2-chambers (anterior-posterior), major and minor axis TA diameters, TA area, perimeter, leaflet tenting height and volume. The 3D TV analysis was made using the 4D Auto TVQ quantification software package. Receiver Operating Characteristic (ROC) curves, area under the curve (AUC), specificity and sensitivity were analysed. Results Study cohort included 66% females; mean age was 65±11 years. The results of the ROC analysis are shown in Table 1. Of all TA 3D parameters, septal-lateral systolic (AUC 0.859) and diastolic (AUC 0.840) diameter, major axis systolic (AUC 0.816) and diastolic (AUC 0.810) diameter, as well as leaflet tenting volume (AUC 0.769) have the highest predictive value for severe FTR. 3D TA analysis provides 75–88% sensitivity for defying pts with severe FTR. Meanwhile, septal-lateral diameter, major axis diameter and annulus perimeter are the most specific to determine severe FTR. 2D echo-derived TA 4-chamber diastolic diameter index has a lower predictive value with worse sensitivity and specificity, compared to 3D parameters. Conclusions Analysis of three-dimensional echocardiographic parameters is an accurate method, suggesting that dilation of tricuspid annulus is a precise measure for identifying patients with severe FTR. Funding Acknowledgement Type of funding sources: None.

A new method for reconstructing the 3D shape of single cells in fruit

Fruit cells’ shape generally reflects the physiological state and quality of the fruit, and indirectly dictates its economics. In this study, a new bio-microscope including three independent and orthogonal channels of opto-electromechanical microscopic observation systems was developed to obtain the three views (e.g., front view, top view, side view) of a single fruit cell using tomato and strawberry at two ripening stages as fruit samples. The obtained three-view images were used to reconstruct the 3D real shape of a single cell based on the 3D geometrical modelling method using Solidworks CAD design software and then compared with the actual geometric size. The average relative errors for the major diameter, minor diameter 1, minor diameter 2, projection perimeter and projection area were 4.04 %, 6.25 %, 5.71 %, 1.69 % and 3.79 %, respectively. This good accuracy makes the newly developed bio-microscope together with the proposed 3D geometrical modelling method a promising 3D shape reconstruction technology for a single fruit cell to extract real and detailed cell morphology information. Furthermore, this method can find applications in other fields such as human and animal cells where soft particles’ 3D shape analysis is important.

Anthropometric Study of Proximal Radius in Below-Average Height Thai Women and Its Correlation with Commercially Available Radial Head Prostheses.

Background: Most radial head prostheses were designed in Western countries based on the anatomical characteristics of Western populations. We hypothesised that these prostheses are too large for below-average height Thai women. The objective of this study is to evaluate the anthropometric parameters of the proximal radius in such a population and its correlation with commercially available prostheses. Methods: Dominant elbows of 124 Thai women whose height was <155 cm were studied. Using the standard anteroposterior and lateral radiographic images, the head diameter and thickness, the distance between the articular surface and radial tuberosity, the narrowest intra-medullary canal diameter and the narrowest outer diameter of the radial neck were measured. Correlations between body height and each radiographic parameter were assessed using the Pearson correlation coefficient (PCC). The specifications of the commercial metallic radial head implants were reviewed and used to evaluate the relevant radiographic parameters. Results: Mean of the minimum and maximum head diameter was 18.54 ± 1.11 mm and 19.13 ± 1.17 mm, respectively; the thickness was 7.43 ± 0.69 mm, the distance between the articular surface and tuberosity was 19.05 ± 1.45 mm, the intra-medullary canal diameter was 7.63 ± 1.2 mm and the outer diameter of the radial neck was 11.13 ± 1.26 mm. There is a poor correlation between the participant's height and each parameter (PCC ≤ 0.50). In 24.2% of the participants, the smallest size of prosthetic designs with a head diameter of 20 mm is larger than +2 mm in reference to minor diameter. The minimum prosthetic head thickness is greater than the average value of the participants in 12 out of 15 designs. One participant has an outer neck diameter smaller than the smallest stem diameter of three designs. Conclusions: Surgeons must be aware that commercially available radial head replacement implants may be too large for below-average height Thai women. Level of Evidence: Level IV (Prognostic).

Data mining-based discriminant analysis as a tool for the study of egg quality in native hen breeds

Despite the wide biodiversity of avian species of zootechnical interest in Spain, projects aimed at characterizing these genotypes and their products are necessary. External and internal egg quality traits were measured in 819 eggs laid by hens of 10 different genotypes: White, Franciscan, Black and Partridge varieties of Utrerana, Blue Andalusian, Spanish White-Faced, Andalusian Tufted White and Black varieties, Araucana; and Leghorn Lohmann LSL-Classic lineage (commercial hybrid line) hen breeds. After multicollinearity analysis of egg quality-related traits was performed (VIF ≤ 4), major diameter, minor diameter, egg weight, and albumen height were deemed redundant explanatory variables and discarded. A stepwise discriminant canonical analysis was developed to cluster eggs across hen genotypes considering egg quality attributes. Shell a* and b* variables reported the highest discriminant power (Wilks’ lambda: 0.699 and 0.729, respectively). The first two discriminant functions captured 60.48% of the variance across groups (F1: 39.36%; F2: 21.12%). Clear quality differentiation signs are evidenced for Mediterranean native breeds’ eggs when compared to Leghorn’s eggs. Consequently, this evidence of egg quality differentiation may favor the standardization of breed- and variety-linked distinctive products, which may open new market opportunities based on the existence of a wide spectrum of diet or culinary applications.

High Latitude Coral Larval Recruitment: Spatiotemporal Process Variability in the Gulf of California1

The aim of this study is to explore if sexual reproduction is present in scleractinian corals at the northern limit of their distribution (28.980° N, 113.470° W) in a zone subject to upwelling and seasonal variations in sea surface temperature, and sampling was performed from August 2018 to October 2019. We placed 42 terracotta recruitment tiles in Bahía de los Ángeles, Baja California. Coral cover was estimated, and the height, major diameter, and minor diameter of coral colonies were measured. Astrangia haimei and Porites panamensis recruits were identified on the recruitment tiles, constituting the first quantitative record for the northeastern tropical Pacific. Recruitment of P. panamensis was higher (Llave: 63.09 ± 114 ind m–2 y–1, Rasito: 3.21 ± 7 ind m–2 y–1), while A. haimei recruitment at the same sites was 3.85 ± 8 and 1.93 ± 6 ind m–2 y–1, respectively. Recruitment differences between locations were attributed to coral cover (the abundance of Porites panamensis is 15-fold greater in Llave than in Rasito) and colony size (P. panamensis Llave: 10.53 ± 5.93 cm, Rasito: 4 ± 0.63 cm). Both SST and Chl-a concentrations were also highly correlated with coral recruitment, with higher recruitment rates observed in the warmer seasons when high nutrient concentrations were also present. In contrast to other sites in the eastern tropical Pacific, the highest rate of recruitment was reported at this study (high-latitude coral community), which, according with the positive high latitude trend reported by other studies, is likely due to climate change.

Reference ranges of tricuspid annulus geometry in healthy adults using a dedicated three-dimensional echocardiography software package.

BackgroundTricuspid annulus (TA) sizing is essential for planning percutaneous or surgical tricuspid procedures. According to current guidelines, TA linear dimension should be assessed using two-dimensional echocardiography (2DE). However, TA is a complex three-dimensional (3D) structure.AimIdentify the reference values for TA geometry and dynamics and its physiological determinants using a commercially available three-dimensional echocardiography (3DE) software package dedicated to the tricuspid valve (4D AutoTVQ, GE).MethodsA total of 254 healthy volunteers (113 men, 47 ± 11 years) were evaluated using 2DE and 3DE. TA 3D area, perimeter, diameters, and sphericity index were assessed at mid-systole, early- and end-diastole. Right atrial (RA) and ventricular (RV) end-diastolic and end-systolic volumes were also measured by 3DE.ResultsThe feasibility of the 3DE analysis of TA was 90%. TA 3D area, perimeter, and diameters were largest at end-diastole and smallest at mid-systole. Reference values of TA at end-diastole were 9.6 ± 2.1 cm2 for the area, 11.2 ± 1.2 cm for perimeter, and 38 ± 4 mm, 31 ± 4 mm, 33 ± 4 mm, and 34 ± 5 mm for major, minor, 4-chamber and 2-chamber diameters, respectively. TA end-diastolic sphericity index was 81 ± 11%. All TA parameters were correlated with body surface area (BSA) (r from 0.42 to 0.58, p < 0.001). TA 3D area and 4-chamber diameter were significantly larger in men than in women, independent of BSA (p < 0.0001). There was no significant relationship between TA metrics with age, except for the TA minor diameter (r = −0.17, p < 0.05). When measured by 2DE in 4-chamber (29 ± 5 mm) and RV-focused (30 ± 5 mm) views, both TA diameters resulted significantly smaller than the 4-chamber (33 ± 4 mm; p < 0.0001), and the major TA diameters (38 ± 4 mm; p < 0.0001) measured by 3DE. At multivariable linear regression analysis, RA maximal volume was independently associated with both TA 3D area at mid-systole (R2 = 0.511, p < 0.0001) and end-diastole (R2 = 0.506, p < 0.0001), whereas BSA (R2 = 0.526, p < 0.0001) was associated only to mid-systolic TA 3D area.ConclusionsReference values for TA metrics should be sex-specific and indexed to BSA. 2DE underestimates actual 3DE TA dimensions. RA maximum volume was the only independent echocardiographic parameter associated with TA 3D area in healthy subjects.

Investigation of the Relationship Between Texture Coefficient and Electrical Current Consumption of the Cutting Machine with Different Lubricants and Cooling Fluids

Texture coefficient is one of the most effective physical factors in evaluating the engineering characteristics of rocks in various projects, such as drilling, cutting and advanced rate of full-face drilling machines. Evaluation of electricity consumption by disc-cutting machines is critical for monitoring and reducing expenses in the stone processing industry. In this study, the relationship between the textural characteristics of the rocks and the amount of electrical current consumed by the cutting machine in cutting hard stones was evaluated. For this purpose, ten samples of hard rock were investigated. For each rock sample, a microscopic slice was prepared. Then, five digital images were taken using the microscope from each division, and the values of textural characteristics, including area, perimeter, largest diameter, and most minor diameter of all grains in each embodiment, were determined. Then, the texture coefficient of all studied stone samples was computed based on the determined specifications. Finally, the relationship between the texture coefficient and the rate of electrical current consumed by the cutting machine was investigated using statistical models. The results revealed that although the electric current used by the cutting machine decreased when the texture coefficient increased in some samples, no significant relationship between the texture coefficient and the amount of electric current used by the cutting machine was observed for hard stone samples. It was also found that the impact of lubricant type on the cutting machine performance is negligible.

Internal morphology of distal roots of mandibular first molars revealed by computed microtomography.

To evaluate the internal morphology of 100 distal roots of mandibular first molars using micro-CT. Teeth were scanned to characterise: Vertucci type, root length, canal shape, presence and location of accessory canals, and the number of foramina at 4 mm from the apex, presence of root isthmus and the length from the primary canal to the apical foramen. Vertucci type I was found in 57% of cases, followed by V (27%). The most common cross-section 1 mm from the apex was oval (49%) and circular (38%). The average root length was 16.06 mm (16.61-19.02 mm). The mean foramen size was 0.32 and 0.53 mm for the minor and major diameters, respectively. The volume, surface area and SMI were 7.84 mm3 , 68.87 mm2 and 1.52 mm, respectively. Root isthmi were found in 47% of the samples, and the length mean from the primary canal to the apical foramen was 2,03 mm. The internal morphology of the distal roots of mandibular first molars may be complex and shows variations.

Development of miniaturized portable metric internal thread contact detector

Because the thread is easy to install, disassemble, and replace, and most of the threads have been standardized, the miniaturized internal thread structure is quite special, the size is extremely small, and the space position is limited, so that the current common measurement mechanism cannot achieve effective measurement. Based on the above reasons, this research aims to develop a portable miniaturized metric internal thread contact detector. The parameter values that can be detected by the detector respectively include the hole diameter value under the inner thread before tapping, the minor diameter value and the major diameter value of the internal thread after tapping. Then, use the quadratic element measuring instrument to measure three parameter values, namely the lower diameter value, the smaller diameter value of the internal thread, and the value of the major diameter of the internal thread. It is then verified with the theoretical value of the metric internal thread, which proves that the experimental parameter values designed in this study are consistent with the theoretical values. That is to say, the miniaturized metric internal thread detector can be applied to any miniaturized metric internal thread detection place, and can accurately detect the obtained parameter values, and can overcome the detection limitation given by the miniaturized internal thread in the space structure. Finally, the easy availability of the detector and the relatively low cost are its main development advantages.