Three-layer Pattern Research Articles

The study on high temperature exhaust orifice infrared suppression

A type of gas turbine generator unit has lots of advantages, such as small size, light weight, advanced technical performance, strong environment adaptability, rapid start. However, the high temperature exhaust gas generated during the operation of the machine leads to the high temperature and obvious infrared radiation characteristics near the exhaust port. The objective of this paper is to investigate the infrared suppression of the exhaust orifice of the gas turbine generator unit. Meanwhile, some schemes about infrared suppression are proposed, that is, redesigning the exhaust cover or adding grid regenerator of high temperature phase change materials(HTPCMs). The method of computer simulation experiment, relying on Gambit and Fluent for modeling, is used to demonstrate the feasibility of the scheme. Results indicate that the first enrichment of gas turbine exhaust heat can be completed and the exhaust temperature can be reduced by about 200°C when the grid is set as a three-layer pattern crisscrossed up and down.

Analysis of three-layer gasket performance affected by flange surface

Gaskets are components that play a very important role in piping connections to prevent leakage. Several factors affect the performance of the gasket, one of which is the contact surface of the flange. The quality of the contact surfaces in the connection also influences the leakage rate of each connection, therefore the gasket sealing performance is assessed by the rate of leakage that occurs. As a result, the surface roughness of the flange has an effect on sealing. This study examines the capability of a three-layer corrugated metal gasket to prevent leakage when the outside layer thickness and flange roughness are adjusted. The feature of three-layer corrugated metal gasket was elucidated using the finite element analysis (FEA) and experimental method. The leak rate was tested using a helium leak quantity test experimentally. The gasket was constructed with oxygen-free copper (C1020) as the outside layer and SUS304 as the base layer, and it was structured in a three-layer pattern with no bonding. A mold press was used to make the gasket. The simulation method applies finite element analysis software to investigate the correlation between contact stress, contact width, surface thickness and surface roughness. The projected results matched the experiment results fairly well. A three-layer corrugated metal gasket shows improvement capability to prevent leakage than a single gasket (standard). The gasket three-layer shows sealing performance improvement that leakage did not occur in low axial force 40 kN for all surface roughness test. In terms of sealing, a three-layer gasket with a low thickness ratio works well. Surface roughness of the flange has no influence on the three-layer gasket

Form and function of the mantle edge in Protobranchia (Mollusca: Bivalvia)

We analyzed, by optical and transmission electron microscopy, the morphology and function of the mantle edge, including the formation of the periostracum, of ten species of protobranchs. Five species from the order Nuculida, four species from the order Nuculanida and one species from the order Solemyida were studied. A second outer fold, which seems to function as a template for the internal marginal crenulations of the valves, is present in the crenulated species of Nucula. The minute non-crenulated Ennucula aegeensis shows the glandular basal cells displaced toward the periostracal groove, resembling a minute additional fold between the outer and middle folds. Intense secretion of glycocalyx, together with active uptake of particles, have been observed in the inner epithelium of the middle mantle fold and the whole epithelium of the inner mantle fold in all the studied species. Contrary to the rest of the bivalves, all the protobranchs analyzed have two basal cells involved in the formation of the external nanometric pellicle of the periostracum, a character that would support the monophyly of protobranchs. A three-layered pattern is the general rule for the periostracum in protobranchs, like for other bivalves. The presence of pouches of translucent layer inside the tanned dark layer under periostracal folds is characteristic of the species with a folded periostracum; its function is unclear but could give flexibility to the periostracum. The non-nacreous internal shell layer and the presence of translucent pouches under periostracal folds in Sarepta speciosa resemble those found in nuculanids. However, the free periostracum is rather similar to those of N. hanleyi and E. aegeensis, with a continuous vesicular layer. All the latter supports the inclusion of Sarepta in the order Nuculanida but could indicate either a basal lineage or that the translucent vesicular layer is an adaptive trait.

A Case Report of Ultrasonographic “Endometrial Three Layer” Pattern: A Unique Finding in Ectopic Pregnancy Recent Perspective

Although diagnostic ultrasonography is playing an increasing role in the investigation of the patient with suspected ectopic pregnancy (EP), it has significant limitations in the very early stages of pregnancy. By sonographically exploring the intrauterine echoes in 45 cases of documented EP, we demonstrated a unique pattern in 28 cases (62.2%). A well-defined spheric structure forming an endometrial three-layer (ETL) pattern was seen, probably formed by a midline echo between the two adjacent edematous proliferative layers of the endometrium, the latter resembling the late proliferative endometrium. In 17 patients with a proved EP (37.8%), the ETL pattern was not demonstrated. However, the ETL was not demonstrated in all 40 cases of early intrauterine pregnancy and all 50 cases of miscarriage. These findings suggest 100% specificity and a sensitivity of 62.2% for the ETL pattern in the diagnosis of EP.

CFRP 소재의 선박용 축계 적용을 위한 비틀림강도 특성

The Carbon Fiber Reinforced Plastic (CFRP) material is recently widely used in the composite industry with excellent rigidity and lightweight properties. A ship shaft system requires high standards of safety on torsional strength capacity. The purpose of this study is to verify the applicability of a CFRP shaft system to take the place of metal shaft systems for ships from a viewpoint of torsional strength. Selection of materials and manufacturing method are executed then two geometrically scaled CFRP shaft system models were designed and manufactured with three-layer patterns. The models were used for a series of torsion tests under single and repeated torsional loading conditions. Detailed design and manufacturing methods for a CFRP ship shaft system are documented and the torsion test results are listed in this paper. The results of this study could be useful guidelines on the development of CFRP ship shaft systems and a test method.

Can spectral doppler high specificity and gray scale nail assessment suggest inflammation in psoriatic arthritis patients and control groups?

Introduction: The use of high resolution ultrasonography (US) has become a very important tool in nail assessment. This study evaluated nails clinical and ultrasound measurements in psoriatic arthritis (PsA) patients. Methods: A cross sectional study was performed with a total of 60 patients, PSA patients, 10 healthy individuals and 6 hand osteoarthritis patients (OA). Only PsA patients meeting the CASPAR criteria were included in the study. Results: Spectral Doppler (sD) was used to analyze 208 nail beds. Nail plates on the gray scale (GS) showed loss of the normal three-layered pattern in 89 nails (45.9%). Power Doppler (PD) signal was detected in 189 nail beds (92.2%), showing inflammatory activity in most of the patients and nails assessed. Resistance index (RI) was significantly lower in PsA patients as compared to control groups in both the longitudinal and transverse planes (p<0.001).Nail enthesitis was observed when RI values were below 0.4, characterizing 100% sensitivity and 96% specificity (p<0.01). Conclusions: Nail US scanning presented statistical significance in PsA patients. Future studies could show many inflammatory situations, requiring treatment assessment.

Typical ultrasound features of various endometrial pathologies described using International Endometrial Tumor Analysis (IETA) terminology in women with abnormal uterine bleeding.

To describe the ultrasound features of different endometrial and other intracavitary pathologies inpre- and postmenopausal women presenting with abnormal uterine bleeding, using the International Endometrial Tumor Analysis (IETA) terminology. This was a prospective observational multicenter study of consecutive women presenting with abnormal uterine bleeding. Unenhanced sonography with color Doppler and fluid-instillation sonography were performed. Endometrial sampling was performed according to each center's local protocol. The histological endpoints were cancer, atypical endometrial hyperplasia/endometrioid intraepithelial neoplasia (EIN), endometrial atrophy, proliferative or secretory endometrium, endometrial hyperplasia without atypia, endometrial polyp, intracavitary leiomyoma and other. For fluid-instillation sonography, the histological endpoints were endometrial polyp, intracavitary leiomyoma and cancer. For each histological endpoint, we report typical ultrasound features using the IETA terminology. The database consisted of 2856 consecutive women presenting with abnormal uterine bleeding. Unenhanced sonography with color Doppler was performed in all cases and fluid-instillation sonography in 1857. In 2216 women, endometrial histology was available, and these comprised the study population. Median age was 49 years (range, 19-92 years), median parity was 2 (range, 0-10) and median body mass index was 24.9 kg/m2 (range, 16.0-72.1 kg/m2 ). Of the study population, 843 (38.0%) women were postmenopausal. Endometrial polyps were diagnosed in 751 (33.9%) women, intracavitary leiomyomas in 223 (10.1%) and endometrial cancer in 137 (6.2%). None (0% (95% CI, 0.0-5.5%)) of the 66 women with endometrial thickness < 3 mm had endometrial cancer or atypical hyperplasia/EIN. Endometrial cancer or atypical hyperplasia/EIN was found in three of 283 (1.1% (95% CI, 0.4-3.1%)) endometria with a three-layer pattern, in three of 459 (0.7% (95% CI, 0.2-1.9%)) endometria with a linear endometrial midline and in five of 337 (1.5% (95% CI, 0.6-3.4%)) cases with a single vessel without branching on unenhanced ultrasound. The typical ultrasound features of endometrial cancer, polyps, hyperplasia and atrophy and intracavitary leiomyomas, are described using the IETA terminology. The detection of some easy-to-assess IETA features (i.e. endometrial thickness < 3 mm, three-layer pattern, linear midline and single vessel without branching) makes endometrial cancer unlikely. Copyright © 2020 ISUOG. Published by John Wiley & Sons Ltd.

Implementation of the toroidal absorption cell with multi-layer patterns by a single ring surface.

We developed a type of toroidal multi-pass cell with multi-layer patterns based on the off-axis model. The effective path length of the original toroidal multi-pass cell is extended several roundtrips in comparison with the single-layer pattern, since the inner surface of the toroidal multi-pass cell is more efficiently utilized. The light pattern has been achieved by using the simple ring surface, which is easy to fabricate. The exact analytical equations for the design of the toroidal multi-pass cell were derived based on analytical vector calculations. A series of numerical ray tracing simulations is presented, and the maximum theoretical optical path length that can be reached is 30 m with a setup of 5 cm column radius. Furthermore, two practical spot patterns are demonstrated with a path length of 8.3 m for a two-layer pattern and 10 m for a three-layer pattern, with respective effective volumes of 63 mL and 94 mL. Furthermore, the fringe effect is substantially reduced to less than 0.5% by the usage of our designed mask.

Upper-mantle density structure in the Philippine Sea and adjacent region and its relation to tectonics

SUMMARY The evolution of the Philippine Sea Plate (PSP) since Jurassic is one of the key issues in the dynamics of lithosphere and mantle. The related studies benefited mostly from seismic tomography which provides velocity structures in the upper mantle. However, the upper-mantle structure is not well resolved compared to the continental areas due to the lack of seismic data in the Philippine Sea. We employ a 3-D gravity inversion constrained by an initial model based on the S-wave tomography (SL2013sv; Schaeffer &amp; Lebedev 2013) to image the density structure of the upper mantle of the PSP and adjacent region. The resulting model shows a three-layer pattern of vertical high-low-high density variation in the upper mantle under the PSP. The thin high-density layer evidences for strong oceanic lithosphere in the West Philippine Sea. The relatively low dense mantle located below the PSP possibly originates from the asthenosphere. The PSP differs from the Pacific and the Indian-Australian plates in the whole depth range, while its structure is similar to the eastern Eurasian and Sunda plates. In the depth range, 200–300 km, the relative high-density zone beneath PSP extends to the Sunda Plate and to the eastern Eurasian Plate. We further estimated the conversion factor of our density model and the velocity model (SL2013sv; Schaeffer &amp; Lebedev 2013) in order to locate the changes of compositional effects in the upper mantle. The negative conversion factor indicates that the compositional changes primarily affect the density anomalies beneath the PSP. We, therefore, describe the layered density structures as ‘sandwich’ pattern, which is unique and different from adjacent regions.

Evolution of the Horizontal Mixing Layer In Shallow Water

Horizontal shear motion of a homogeneous fluid in an open channel is considered in the approximation of the shallow water theory. The main attention is paid to studying the mixing process induced by the development of the Kelvin–Helmholtz instability and by the action of bottom friction. Based on a three-layer flow pattern, an averaged one-dimensional model of formation and evolution of the horizontal mixing layer is derived with allowance for friction. Steady solutions of the equations of motion are constructed, and the problem of the mixing layer structure is solved. The bottom friction produces a stabilizing effect and reduces the growth of the mixing layer. Verification of the proposed one-dimensional model is performed through comparisons with available experimental data and with the numerical solution of the two-dimensional equations of the shallow water theory.

Prediction of cesarean section scar dehiscence before delivery using three-dimensional transabdominal ultrasonography

Objective This study aimed to evaluate the efficacy of three-dimensional (3D) ultrasonography in the prediction of cesarean scar dehiscence in pregnant patients at term and to compare the outcome of measurement with the intraoperative visual assessment of the scar. Design This was a prospective study. Patients and methods Seventy pregnant women with a history of a previous cesarean section attending Benha University Hospital were included in this study. All participants underwent a 3D transabdominal scan at third trimester and the data were recorded. We measured the lower segment thickness from the muscularis and mucosa of the bladder on the outer side to the chorioamniotic membrane on the inner side, with the myometrium in between, and hence, depending on a three-layered pattern. This was compared with the pregnancy outcome and the intraoperative scar condition. The data were then statistically analyzed. Results The mean scar thickness as measured by 3D transabdominal sonography in the third trimester was 4.63 ± 0.85 mm. The best cut-off level for predicting uterine scar defects was less than or equal to 2.75 mm (highest diagnostic accuracy) with sensitivity 25%, specificity 100%, positive predictive value 100%, and negative predictive value 95%. Conclusion The current study suggests that prenatal 3D US examination determining the degree of lower uterine segment thinning in patients with previous cesarean delivery provides an additional element for assessing the risk of uterine rupture and may increase safe management of trial of labor.

On thermohaline structure and circulation of the Western Large Aral Sea from 2009 to 2011: Observations and modeling

The shrinkage of the Aral Sea in the second half of the past century has significantly affected the hydrophysical regime of the lake. The objective of this paper is to report on a hydrological structure and circulation of the today's Aral Sea based on both direct field observations and modeling results. We focus on the results of three field surveys to the Aral Sea which took place in the period from 2009 to 2011. In addition, series of numerical experiments using Princeton Ocean Model adapted to the Aral Sea was undertaken to investigate the contributions from bathymetry and water stratification in the formation of the basin scale circulation. The hydrological structure of the Aral's western basin in autumn season exhibited a three-layered pattern with two local salinity maxima, separated by a fresher intermediate layer. According to direct observations, water circulation in the surface layer has anti-cyclonic character, while circulation in the bottom layer has cyclonic sign under the predominant northerly winds. The simulation experiments demonstrated clearly that the main cause of the anti-cyclonic circulation in the surface layer of the lake is the “asymmetric” bathymetry with broad shallow area along the eastern coast and relatively steep and deep western slope. However, strong stratification is a necessary condition for the formation of the cyclonic circulation gyre in the bottom layer.

Analysis of the layering pattern of the apparent diffusion coefficient (ADC) for differentiation of radiation necrosis from tumour progression

To evaluate the added value of diffusion-weighted imaging (DWI) to perfusion-weighted imaging (PWI) for differentiating tumour progression from radiation necrosis. Sixteen consecutive patients who underwent removal of a metastatic brain tumour that increased in size after stereotactic radiosurgery were retrospectively reviewed. The layering of the ADC was categorised into three patterns. ADC values were measured on each layer, and the maximum rCBV was measured. rCBV and the layering pattern of the ADC of radiation necrosis and tumour progression were compared. Nine cases of radiation necrosis and seven cases of tumour progression were pathologically confirmed. Radiation necrosis (88.9 % vs. 14.3 %) showed a three-layer pattern of ADC with a middle layer of minimum ADC more frequently. If rCBV larger than 2.6 was used to differentiate radiation necrosis and tumour progression, the sensitivity was 100 % but specificity was 56 %. If the lesions with the three-layer pattern of ADC with moderately increased rCBV (2.6-4.1) were excluded from tumour progression, the sensitivity and specificity increased to 100 %. The three-layer pattern of ADC shows high specificity in diagnosing radiation necrosis; therefore, combined analysis of the ADC pattern with rCBV may have added value in the correct differentiation of tumour progression from radiation necrosis.

Effects of vegetation channel banks and gravel size on flow structure

Vegetation on river banks and bed roughness are important factors affecting flow structure, sediment transport, erosion and geomorphology in rivers. In this experimental study, the impacts of vegetation on flume walls, grain size of bed gravels and aspect ratio on characteristics of shear stress distribution, Coles' wake parameter, the kinematic energy correction factor (α) and the momentum correction factor (β) have been assessed. Reynolds stress distribution illustrates a three-layer pattern when the aspect ratio is smaller than 2. In addition, the aspect ratio and changes of vegetation affect α, β as well as the Coles' wake parameter Π.

Seasonality of the circulation in the Ría de Muros (NW Spain)

In the Ría de Muros, the northernmost of the four large coastal embayments on the NW coast of the Iberian Peninsula known as Rías Baixas, river discharges, winds and tides are the main agents driving the circulation. Both river discharges and winds present a high degree of seasonality: river flows are typically low in summer and high in winter, and the direction of prevailing winds is N–NE in spring–summer and S–SW in fall–winter. This seasonality may be expected to affect the circulation in the ría. To investigate this, a 3D, baroclinic model is implemented with an unconventional mixed boundary condition at the open (ocean) boundary. Once validated by comparing simulated and observed data of water level, current velocity and salinity, the model is applied to computing the circulation in four cases representative of typical summer and winter scenarios. In each case the model is forced by a specific combination of driving agents, including river runoff, tide and, in some cases, wind. A two-layer circulation pattern with bottom inflow and surface outflow (positive estuarine circulation) exists in the summer cases as well as in the winter case without wind, but its intensity varies greatly. It is weak in typical summer conditions in the absence of wind, but very strong in typical winter conditions also in the absence of wind due to the increase of baroclinic effects brought about by the high river discharges. Moreover, the winds characteristic of summer (N–NE) and winter (S–SW) have markedly different effects when added to the hydrodynamic forcing characteristic of the respective season. While the N–NE wind strengthens the summer no-wind circulation, the S–SW wind transforms the winter no-wind circulation into a three-layer pattern—previously undescribed in the Rías Baixas—in which the surface layer is mostly at rest, outflow resumes immediately underneath, and inflow continues at lower levels. The fact that the S–SW wind is incapable of triggering a negative estuarine circulation in the face of winter average river flows is indicative of the fundamental importance of baroclinic effects in the Ría de Muros. In sum, the seasonal variability of river discharges and winds is found to have a substantial effect on the circulation in the ría.

An ImmunoChip prototype for simultaneous detection of antiepileptic drugs using an enhanced one-step homogeneous immunoassay

The development and characterization of a one-step homogeneous immunoassay-based multiwell ImmunoChip is reported for the simultaneous detection and quantitation of antiepileptic drugs (AEDs). The assay platform uses a cloned enzyme donor immunoassay (CEDIA) and a Beta-Glo assay system for generation of bioluminescent signal. Results of the one-step CEDIA for three AEDs (carbamazepine, phenytoin, and valproic acid), in the presence of serum, correlate well with the values determined by fluorescence polarization immunoassay. CEDIA intra- and interassay coefficients of variation are less than 10%. A microfabrication process, xurography, was used to produce the multiwell ImmunoChip. Assay reagents were dispensed and lyophilized in a three-layer pattern. The multiwell ImmunoChip prototype was used to detect and quantify AEDs in serum samples containing all three drugs. Luminescent signals generated from each well were recorded with a charge-coupled device (CCD) camera. The assays performed on an ImmunoChip were fast (5 min), requiring only small volumes of both the reagents (<1 μl/well) and the serum sample. The ImmunoChip assay platform described in this article may be well suited for therapeutic monitoring of drugs and metabolites at the point-of-care setting.

Oil Water Flow Through Different Diameter Pipes: Similarities and Differences

A survey of the past literature shows that the studies on liquid–liquid flows have primarily been carried out in pipe diameters of 0.025 m or more and no significant influence of conduit size on flow patterns was reported. An interest is felt in the present work to extend the study to pipe diameters lower than 0.025 m and note the difference in the phase distribution (if any). The flow patterns are observed both visually and by photography in two test rigs of diameters 0.025 m and 0.012 m, respectively. The experiments indicate a marked influence of conduit size on flow patterns. The rivulet flow and the churn flow pattern are observed in the narrower pipe and the three-layer pattern which is noted in the 0.025 m pipe is absent in the latter case. The reason behind this has been attributed to the increased effect of surface tension and equilibrium contact angle in the narrow pipe. Additional efforts have been made to understand the influence of mixer design on the downstream flow patterns. It is noted that mixer design does influence the distribution of the two liquids and a properly designed mixer can increase or decrease the range of existence of any flow regime.

Ultrasound examination of the endometrium before and after Pipelle endometrial sampling

To evaluate if, and to what extent, Pipelle de Cornier endometrial sampling influences the ultrasonographic features of the endometrium. This was a prospective descriptive study on 99 consecutive women in whom a Pipelle endometrial biopsy was performed. All patients first underwent a transvaginal ultrasound evaluation of the uterus. The endometrial thickness (ET) was measured and endometrial sonographic features were recorded. Thereafter, a Pipelle endometrial biopsy was taken. Finally, the ultrasound examination was repeated. The patients' characteristics, the sampling procedure, the endometrial histology and the sonographic findings before and after Pipelle biopsy were compared. Ninety-nine women, of whom 45% were postmenopausal, entered the study. The mean age was 59.0 years (SD, 9.9) for the postmenopausal women, and 41.6 years (SD, 8.7) for the rest. On histological examination, endometrial cancer was diagnosed in four patients and endometrial hyperplasia in eight patients. The average ET before Pipelle sampling was 9.0 mm (SD, 6.6) vs. 8.6 mm (SD, 7.0) after biopsy (P < 0.0001). After Pipelle sampling, the endometrium was less clearly delineated (P = 0.03) and more echogenic endometrial spots were seen (P < 0.0001). If an endometrial three-layer pattern was noted before sampling, it was not observed in most women after Pipelle biopsy (P = 0.0003). ET measurements are affected by Pipelle sampling and the quality of the ultrasound features tends to be altered by biopsy. Performing the ultrasound examination before proceeding with endometrial sampling may therefore improve diagnostic accuracy of ultrasound.

The influence of hormone replacement therapy on the ultrasound features of the endometrium: a prospective study

Purpose: To evaluate the thickness and the sonographic features of the endometrium in postmenopausal women on hormone replacement therapy (HRT). Methods: A total of 485 vaginal ultrasound examinations were performed in 239 consecutive postmenopausal women on HRT. Endometrial thickness (ET) was measured and other sonographic features were recorded. Endometrial sampling was performed if indicated. Results: Mean age was 55.1 years (SD 5.7) with an average parity of 1.8 (SD 1.0). The mean age at menopause was 49.7 years (SD 3.6). Sixty-four percent of women were on sequential estro-progestogen therapy, 23.7% on continuous estro-progestogen, and 22% took tibolone. The average ET was 5.2 mm (SD 2.7), 5.7 mm (SD 2.7) in women taking sequential HRT, vs. 4.3 mm (SD 2.3) in the continuous estro-progestogen schemes, and 4.6 mm (SD 1.3) in the tibolone group. In the sequential schemes mean ET measured 5.7 (SD 2.6) in the first estrogen-alone phase of cycle vs. 5.8 mm (SD 2.9) in the estro-progestogen phase. Polyps were diagnosed by ultrasound in 12.1% of patients: more than half of them (54.5%) were asymptotic. In sequential HRT, a three-layer ultrasound pattern of the endometrium was seen in 49.4% of women in the estrogen-alone phase of cycle vs. 13.3% in the estro-progestogen phase. About 3.5% of women on continuous estro-progestogen and 13.8% of the tibolone group showed a three-layer pattern. Conclusions: 1 The same cut-off values for endometrial thickness proposed in postmenopausal women without HRT cannot be used in patients on HRT. 2 A sonographic evaluation performed in the estrogen-alone phase of cycle may optimize the accuracy for focal lesion detection in women on sequential HRT. 3 The issue of the relatively high incidence of polyps in asymptotic women on HRT has to be addressed in order to avoid overtreatment.

Edge pinning effect in single- and three-layer patterns

Magnetization reversal of patterned magnetic structure consisting of single and double coupled ultrathin magnetic layers is simulated by solving Landau–Lifshitz equations. Barkhausen’s steps on the magnetization hysteresis loop originating from magnetization lateral edge pinning are predicted and analyzed in dependence on the size of rectangle patterns for Permalloy films.