Academic literature on the topic 'High thickness variations'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'High thickness variations.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Journal articles on the topic "High thickness variations":
1
Stockert, Sven, Matthias Wehr, Johannes Lohmar, Gerhard Hirt, and Dirk Abel. "Development of a Laser Triangulation Gauge for High Precision Strip Thickness Control." Advanced Materials Research 1140 (August 2016): 107–14. http://dx.doi.org/10.4028/www.scientific.net/amr.1140.107.
Abstract:
Almost all metal strips with thicknesses of < 2 mm are produced by cold rolling. Thickness variations of cold rolled strips are caused by various factors like fluctuation in strength of the material, the eccentricity of the rolls or thickness variation of the incoming strip. As the demands concerning the thickness variation are ever increasing the Institute of Automatic Control and the Institute of Metal Forming aim at reducing the thickness tolerance of thin, cold-rolled steel and copper strips to 1 μm. As high frequency disturbances are expected, it is assumed that this goal can only be achieved by using a predictive controller in combination with a high precision strip thickness gauge and, for roll adjustment, a piezoelectric actuator in addition to the existing electromechanical actuator. The objective of this work is the constructive implementation and the testing of a thickness gauge based on laser triangulation. The gauge includes guide rollers to prevent strip vibration, a C-frame to allow an inline calibration and mechanical adjustment of the measuring range so that even flexible strip thicknesses can be measured. The designed gauge showed a high repeat accuracy of 0.4 μm for two different metal strips. Furthermore the gauge was used to investigate the dynamics of the thickness change of a steel strip at maximum rolling speed of 5 m/s using a Fourier transformation. This frequency analysis supports the need for a piezoelectric actuator that can also subsequently be dimensioned based on the obtained frequency data.
2
Feng, Jian, Yuqiang Zhang, Na Xu, Bo Chen, Tong Xu, Zhensen Wu, Zhongxin Deng, et al. "Statistical Study of the Ionospheric Slab Thickness at Yakutsk High-Latitude Station." Remote Sensing 14, no. 21 (October 24, 2022): 5309. http://dx.doi.org/10.3390/rs14215309.
Abstract:
The ionospheric equivalent slab thickness (EST, also named τ) is defined as the ratio of the total electron content (TEC) to the F2-layer peak electron density (NmF2), and it is a significant parameter representative of the ionosphere. This paper presents a comprehensive statistical study of the ionospheric slab thickness at Yakutsk, located at the high latitude of East Asia, using the GPS-TEC and ionosonde NmF2 data for the years 2010–2017. The results show that the τ has different diurnal and seasonal variations in high- and low-solar-activity years, and the τ is greatest in the winter, followed by the equinox, and it is smallest in the summer in both high- and low-solar-activity years, except during the noontime of low-solar-activity years. Specifically, the τ in inter of high-solar-activity year shows an approximate single peak pattern with the peak around noon, while it displays a double-peak pattern with the pre-sunrise and sunset peaks in winter of the low-solar-activity years. Moreover, the τ in the summer and equinox have smaller diurnal variations, and there are peaks with different magnitudes during the sunrise and post-sunset periods. The mainly diurnal variation of τ in different seasons of high- and low-solar-activity years can be explained within the framework of relative variation of TEC and NmF2 during the corresponding period. By defining the disturbance index (DI), which can visually assess the relationship between instantaneous values and the median, we found that the geomagnetic storm would enhance the τ at Yakutsk. An example on 7 June 2013 is also presented to analyze the physical mechanism. It should be due to the intense particle precipitation and expanded plasma convection electric field during the storm at high-latitude Yakutsk station. The results would improve the current understanding of climatological and storm-time behavior of τ at high latitudes in East Asia.
3
Rizqi Widyanti, Elvira, Choirul Anam, Eko Hidayanto, Ariij Naufal, and Mohammad Haekal. "An evaluation of automated measurement of slice sensitivity profile of computed tomography image: field of view variations." Indonesian Journal of Electrical Engineering and Computer Science 29, no. 3 (March 1, 2023): 1430. http://dx.doi.org/10.11591/ijeecs.v29.i3.pp1430-1437.
Abstract:
This study aims to evaluate the automated measurement of slice sensitivity profile (SSP) on the American Association of Physicists in Medicine (AAPM) computed tomography (CT) performance phantom for variations of slice thickness and field of view (FOV). The AAPM CT performance phantom was scanned using a Philips MRC 880 CT Scanner for variations of slice thickness and FOV. The slice thickness values were 1, 3, and 5 mm. The FOV values were 240, 300, 340, 400, and 440 mm. The automated SSPs and their fullwidth at half maximums (FWHMs) were automatically measured from the middle stair object of the phantom. To validate the automated measurement results, the FWHM values of SSPs obtained were compared to those from manual measurements. The differences between FWHMs from automated measurements and set slice thicknesses are less than 0.3 mm, while the differences between FWHMs from automated and manual measurements are less than 0.2 mm. The results from automated measurements are closer to the set slice thickness than those from manual measurements. This automated SSP measurement provides high accuracy and precision for both the slice thickness and the FOV variations.
4
Garbe, S., Dorte Juul Jensen, Henning Friis Poulsen, N. C. Krieger Lassen, and Dierk Raabe. "Through-Thickness Texture Variations Determined Non-Destructively by High Energy Synchrotron Radiation." Materials Science Forum 273-275 (February 1998): 271–76. http://dx.doi.org/10.4028/www.scientific.net/msf.273-275.271.
5
Morina, Edona, Marius Dotter, Christoph Döpke, Ilda Kola, Tatjana Spahiu, and Andrea Ehrmann. "Homogeneity of Needleless Electrospun Nanofiber Mats." Nanomaterials 13, no. 18 (September 6, 2023): 2507. http://dx.doi.org/10.3390/nano13182507.
Abstract:
Nanofiber mats can be electrospun by different techniques, usually subdivided into needle-based and needleless. The latter allow for producing large-area nanofiber mats, e.g., with a width of 50 cm and lengths of several meters, if electrospinning proceeds for several hours, depending on the required thickness. Even spinning smaller samples, however, raises the question of homogeneity, especially if defined mechanical properties or a defined thickness is required, e.g., for filtration purposes. Very often, only the inner parts of such electrospun nanofiber mats are used to avoid too high variation of the nanofiber mat thickness. For this study, we used wire-based electrospinning to prepare nanofiber mats with slightly varying spinning parameters. We report investigations of the thickness and mass per unit area, measured on different positions of needleless electrospun nanofiber mats. Martindale abrasion tests on different positions are added as a measure of the mechanical properties. All nanofiber mats show unexpectedly strong variations of thickness, mass per unit area, and porosity, as calculated from the apparent density of the membranes. The thickness especially varied by nearly one order of magnitude within one sample, while the apparent density, as the most uniform parameter, still showed variations by more than a factor of two within one sample. This shows that even for apparently highly homogeneous areas of such nanofiber mats, variations cannot be neglected for all potential applications.
6
George, Daniel, Stéphane Pallu, Céline Bourzac, Rkia Wazzani, Rachele Allena, Yves Rémond, and Hugues Portier. "Prediction of Cortical Bone Thickness Variations in the Tibial Diaphysis of Running Rats." Life 12, no. 2 (February 3, 2022): 233. http://dx.doi.org/10.3390/life12020233.
Abstract:
A cell-mechanobiological model is used for the prediction of bone density variation in rat tibiae under medium and high mechanical loads. The proposed theoretical-numerical model has only four parameters that need to be identified experimentally. It was used on three groups of male Wistar rats under sedentary, moderate intermittent and continuous running scenarios over an eight week period. The theoretical numerical model was able to predict an increase in bone density under intermittent running (medium intensity mechanical load) and a decrease of bone density under continuous running (higher intensity mechanical load). The numerical predictions were well correlated with the experimental observations of cortical bone thickness variations, and the experimental results of cell activity enabled us to validate the numerical results predictions. The proposed model shows a good capacity to predict bone density variation through medium and high mechanical loads. The mechanobiological balance between osteoblast and osteoclast activity seems to be validated and a foreseen prediction of bone density is made available.
7
Zhang, Qianwen, Xue Chu, Zhipeng Gao, Yulong Ding, Feng Que, Zishan Ahmad, Fen Yu, Muthusamy Ramakrishnan, and Qiang Wei. "Culm Morphological Analysis in Moso Bamboo Reveals the Negative Regulation of Internode Diameter and Thickness by Monthly Precipitation." Plants 13, no. 11 (May 28, 2024): 1484. http://dx.doi.org/10.3390/plants13111484.
Abstract:
The neglect of Moso bamboo’s phenotype variations hinders its broader utilization, despite its high economic value globally. Thus, this study investigated the morphological variations of 16 Moso bamboo populations. The analysis revealed the culm heights ranging from 9.67 m to 17.5 m, with average heights under the first branch ranging from 4.91 m to 7.67 m. The total internode numbers under the first branch varied from 17 to 36, with internode lengths spanning 2.9 cm to 46.4 cm, diameters ranging from 5.10 cm to 17.2 cm, and wall thicknesses from 3.20 mm to 33.3 mm, indicating distinct attributes among the populations. Furthermore, strong positive correlations were observed between the internode diameter, thickness, length, and volume. The coefficient of variation of height under the first branch showed strong positive correlations with several parameters, indicating variability in their contribution to the total culm height. A regression analysis revealed patterns of covariation among the culm parameters, highlighting their influence on the culm height and structural characteristics. Both the diameter and thickness significantly contribute to the internode volume and culm height, and the culm parameters tend to either increase or decrease together, influencing the culm height. Moreover, this study also identified a significant negative correlation between monthly precipitation and the internode diameter and thickness, especially during December and January, impacting the primary thickening growth and, consequently, the internode size.
8
Jalali-Vahid, D., Z. M. Jin, and D. Dowson. "Elastohydrodynamic lubrication analysis of hip implants with ultra high molecular weight polyethylene cups under transient conditions." Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science 217, no. 7 (July 1, 2003): 767–77. http://dx.doi.org/10.1243/095440603767764417.
Abstract:
The transient variation of both the load and speed experienced during walking in an elastohydrodynamic lubrication (EHL) analysis for artificial hip joints employing an ultra high molecular weight polyethylene (UHMWPE) acetabular cup against either a metallic or ceramic femoral head was considered in this study. A general numerical procedure to solve the transient EHL problem in spherical ball-in-socket coordinates, developed in a previous study by Jalali-Vahid and Jin in 2002, was applied under three specific conditions experienced during typical gait cycles, including speed reversal, a sudden load increase and a sudden load decrease. The predicted minimum film thickness was found to stay remarkably constant and similar to that prior to the change in either the load or the angular velocity, despite a large change in these operating conditions. This was attributed to the remarkably effective squeeze-film action of preserving and maintaining the lubricating film developed before the transient variations in either the load or speed. It is therefore possible to neglect the effect of these specific transient variations of load and speed under physiological walking conditions considered in the present study on the predicted film thickness in hip implants with UHMWPE cups.
9
Tu, Qianguang, Yun Zhao, Jing Guo, Chunmei Cheng, Liangliang Shi, Yunwei Yan, and Zengzhou Hao. "Spatial and Temporal Variations of Aerosol Optical Thickness over the China Seas from Himawari-8." Remote Sensing 13, no. 24 (December 14, 2021): 5082. http://dx.doi.org/10.3390/rs13245082.
Abstract:
Six years of hourly aerosol optical thickness (AOT) data retrieved from Himawari-8 were used to investigate the spatial and temporal variations, especially diurnal variations, of aerosols over the China Seas. First, the Himawari-8 AOT data were consistent with the AERONET measurements over most of the China Seas, except for some coastal regions. The spatial feature showed that AOT over high latitude seas was generally larger than over low latitude seas, and it is distributed in strips along the coastline and decreases gradually with increasing distance from the coastline. AOT undergoes diurnal variation as it decreases from 9:00 a.m. local time, reaching a minimum at noon, and then begins to increase in the afternoon. The percentage daily departure of AOT over the East China Seas generally ranged ±20%, increasing sharply in the afternoon; however, over the northern part of the South China Sea, daily departure reached a maximum of >40% at 4:00 p.m. The monthly variation in AOT showed a pronounced annual cycle. Seasonal variations of the spatial pattern showed that the largest AOT was usually observed in spring and varies in other seasons for different seas.
10
Zachariah, T., S. B. Rawal, S. N. Pramanik, M. V. Singh, S. Kishnani, H. Bharadwaj, and R. M. Rai. "Variations in skinfold thickness during de-acclimatisation and re-acclimatisation to high altitude." European Journal of Applied Physiology and Occupational Physiology 56, no. 5 (1987): 570–76. http://dx.doi.org/10.1007/bf00635372.
Dissertations / Theses on the topic "High thickness variations":
1
Belhachmi, Ayoub. "Une méthode implicite pour la construction des modèles géologiques complexes via une interpolation à l'aide des splines et une régularisation basée sur les équations aux dérivées partielles." Electronic Thesis or Diss., Université Côte d'Azur, 2024. http://www.theses.fr/2024COAZ5000.
Abstract:
La construction d'un géomodèle numérique est une étape clé dans l'étude et l'exploration du sous-sol. Ces modèles sont construits à partir de données sismiques ou de puits, qui forment un ensemble de points de données associés à des valeurs correspondant à leurs âges géologiques. Cette tâche consiste à construire une fonction implicite, également appelée fonction stratigraphique, qui interpole cet ensemble de points de données. Souvent, les données disponibles sont rares et bruitées, ce qui rend cette tâche difficile, principalement pour les réservoirs où les structures géologiques sont complexes avec plusieurs discontinuités. Pour résoudre ce problème, le problème d'interpolation est généralement complété par un terme de régularisation qui impose un comportement régulier de la fonction implicite. Dans cette thèse, nous proposons une nouvelle méthode pour calculer la fonction stratigraphique qui représente les couches géologiques dans des contextes arbitraires. Dans cette méthode, les données sont interpolées par des splines Powell-Sabin C^1 quadratiques par morceaux et la fonction peut être régularisée via de nombreuses énergies de régularisation. La méthode est discrétisée en éléments finis sur un maillage triangulaire conforme aux failles géologiques. Par rapport aux méthodes d'interpolation classiques, l'utilisation de splines quadratiques par morceaux présente deux avantages majeurs. Premièrement, une meilleure approximation des surfaces stratigraphiques présentant de fortes courbures. Deuxièmement, une réduction de la résolution du maillage, tout en générant des surfaces plus lisses et plus régulières.La régularisation de la fonction est la composante la plus difficile de toute approche de modélisation implicite. Souvent, les méthodes classiques produisent des modèles géologiques incohérents, en particulier pour les données présentant de fortes variations d'épaisseur, et des effets de bulles sont généralement observés. Pour résoudre ce problème, nous introduisons deux nouvelles énergies de régularisation liées à deux EDPs fondamentales, sous leur forme générale avec des coefficients variants spatialement. Ces EDPs sont l'équation de diffusion anisotrope et l'équation de flexion d'une plaque mince anisotrope. Dans la première approche, le tenseur de diffusion est introduit et adapté de manière itérative aux variations et à l'anisotropie des données. Dans la seconde, le tenseur de rigidité est adapté de manière itérative aux variations et à l'anisotropie des données. Nous démontrons l'efficacité des méthodes proposées en 2D, spécifiquement sur des coupes transversales de modèles géologiques avec des réseaux de failles complexes et des couches géologiques présentant des variations d'épaisseurThe construction of a geological numerical model is a key step in the study and exploration of the subsurface. These models are constructed from seismic or well data, which consist of data points associated with values corresponding to their geological ages. This task involves constructing an implicit function, known also as stratigraphic function, which interpolates this set of data points. Often the available data are sparse and noisy, which makes this task difficult, mainly for reservoirs where the geological structures are complex with distinct discontinuities and unconformities. To address this, the interpolation problem is typically supplemented with a regularization term that enforces a regular behaviour of the implicit function. In this thesis, we propose a new method to compute the stratigraphic function that represents geological layers in arbitrary settings. In this method, the data are interpolated by piecewise quadratic C^1 Powell-Sabin splines and the function can be regularized via many regularization energies. The method is discretized in finite elements on a triangular mesh conforming to the geological faults. Compared to classical interpolation methods, the use of piecewise quadratic splines has two major advantages. First, a better handling of stratigraphic surfaces with strong curvatures. Second, a reduction in mesh resolution, while generating surfaces of higher smoothness and regularity.The regularization of the function is the most difficult component of any implicit modeling approach. Often, classical methods produce inconsistent geological models, in particular for data with high thickness variation, and bubble effects are generally observed. To handle this problem, we introduce two new regularization energies that are linked to two fundamental PDEs, in their general form with spatially varying coefficients. These PDEs are the anisotropic diffusion equation and the equation that describes the bending of an anisotropic thin plate. In the first approach, the diffusion tensor is introduced and iteratively adapted to the variations and anisotropy of the data. In the second, the rigidity tensor is iteratively adapted to the variations and anisotropy in the data. We demonstrate the effectiveness of the proposed methods in 2D, specifically on cross-sections of geological models with complex fault networks and thickness variations in the layers
2
Damodar, Hemlata-Rahul, and 戴牧恬. "Online Monitoring of Fouling Layer Thickness Variation in Membrane Filter for High Turbidity Influent Treatment Using Photo-interrupt Sensor." Thesis, 2011. http://ndltd.ncl.edu.tw/handle/21818224202401787550.
Abstract:
碩士中原大學
化學工程研究所
99
Membrane fouling is an unfavorable but inevitable problem in membrane filtration process. Online monitoring techniques can play a major role in understanding its formation mechanism and this may helpful to accomplish a better control over reduction of membrane fouling. Numerous destructive and non-destructive experimental methods were developed for the direct and indirect measurement of cake layer thickness. The present study describes an application of an in-situ optical method to determine the growth of fouling layer by using photo-interrupt sensor. This technique can be effectively used to non-destructively measure or monitor cake thickness as a function of time. In order to verify the validity of this method, the effect of voltage (10 – 12 V), slurry concentration (0 – 2 g/L), and membrane material (PVDF and PTFE) on sensor signal were examined. In addition, the application of this method for monitoring the growth of fouling cake layer thickness during filtration of high turbidity wastewater under different conditions of flux (50 – 200 LMH), aeration (continuous and semi-continuous at 1 – 1.5 L/min) and suction (continuous and semi-continuous) were studied. The Degussa P25 TiO2 particles were selected for filtration and calibration experiments. Results showed that as TiO2 particle concentration increases the slope of sensor calibration plot decreases. As input voltage increase from 10 to 12V, results showed that the calibration curve attends more linearity and increased sensitivity at all TiO2 concentration. It was also observed that the sensor signal (voltage) fluctuation at 12V and at higher concentration of TiO2 particles (>1.5 g/L) was higher than that at 10V. The PTFE membrane showed better sensitivity as compared to PVDF membrane. From the filtration experiment it was observed that at lower flux the fouling is more at the bottom than at the top of the membrane. But as the flux increases the cake layer become more and more uniform. It was also observed that TMP rise was not so severe at low flux due to low and irregular fouling. But at high flux the TMP increases rapidly and attends a constant value. The cake thickness around entire surface area of the membrane was suppressed due to continuous aeration. The semi-continuous aeration could also suppress the membrane fouling at the same level as observed at continuous aeration. The combination of suction and relaxation at different conditions can only reduces the growth rate of fouling cake layer thickness, but extent fouling was not suppressed. The application of suction and backflow mode with sufficient backflow period conditions can suppress the fouling drastically to the same extent that observed during semi-continuous aeration condition.
3
Tseng, Wen-Chin, and 曾文錦. "A Study of High Voltage SOI Devices with a Variation of Linearly Graded Drift Region and Linear Thickness Drift Region." Thesis, 2009. http://ndltd.ncl.edu.tw/handle/86643877407959875868.
Abstract:
碩士亞洲大學
資訊工程學系碩士班
97
An optimal variation in lateral doping profiles is proposed for the drift region of lateral power devices in partial SOI technology in order to achieve breakdown voltage above 200V for both off-state and on-state operations. LDMOS structure incorporating the proposed optimal doping profile are analyzed for their electrical characteristics and compared with conventional uniformly doped SOI and thin layer SOI by extensive 2D numerical simulations using MEDICI. The results indicate that the proposed optimal doping profile is in good agreement with the optimal doping gradient for JI technology. The optimal doping gradient can significantly improve the trade-off between breakdown voltage and specific on-resistance in comparison to uniformly doped SOI. In this study we also show a physical method to design SOI device with linear doping profile. A drift region with linear thickness (LT) is proposed to uniform the lateral electric fields and increase impurity levels. The linear thickness (LT) device using the physical method delivers a significant reduction of the on-resistance without compromising the breakdown voltage capability in comparison with the lateral linear doping technology. Therefore, the new LDMOS provides an excellent BFOM value, which is double of conventional RESURF devices and linear doping devices. Furthermore, improved kink and quasi-saturation effects are also found in the linear thickness (LT) device , thus resulting in an optimal safe operating area.
Book chapters on the topic "High thickness variations":
1
John Shammas, H., and Maya C. Shammas. "Biometry Measurements Using a New Large Coherence Length Swept-Source Optical Coherence Tomography." In Intraocular Lens Calculations, 313–20. Cham: Springer International Publishing, 2024. http://dx.doi.org/10.1007/978-3-031-50666-6_19.
Abstract:
AbstractThe swept-source OCT biometer (Argos) uses a 1060 nm wavelength and 20 nm bandwidth swept-source technology to collect 2-D OCT data of the full eye. The device measures the axial length and the anterior chamber depth, the central corneal thickness, aqueous depth, lens thickness, pupil size, the corneal diameter, and the corneal power in less than a second. The repeatability and reproducibility of the Argos measurements have been tested by means of variation analysis study and demonstrated that the new OCT biometer produces precise and reproducible measurements. Measurements made with the swept-source OCT biometer show a high acquisition rate compared with the IOLMaster 500 and the Lenstar biometers, especially in dense cataracts. The Argos swept-source optical coherence tomography measures the optical path length of each segment of the eye and uses a specific refractive index for each of these segments that has led to an improvement in IOL power calculation especially in long and short eyes.
2
Peter, Johannes M. F., and Markus J. Kloker. "Numerical Simulation of Film Cooling in Supersonic Flow." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 79–95. Cham: Springer International Publishing, 2020. http://dx.doi.org/10.1007/978-3-030-53847-7_5.
Abstract:
Abstract High-order direct numerical simulations of film cooling by tangentially blowing cool helium at supersonic speeds into a hot turbulent boundary-layer flow of steam (gaseous H2O) at a free stream Mach number of 3.3 are presented. The stagnation temperature of the hot gas is much larger than that of the coolant flow, which is injected from a vertical slot of height s in a backward-facing step. The influence of the coolant mass flow rate is investigated by varying the blowing ratio F or the injection height s at kept cooling-gas temperature and Mach number. A variation of the coolant Mach number shows no significant influence. In the canonical baseline cases all walls are treated as adiabatic, and the investigation of a strongly cooled wall up to the blowing position, resembling regenerative wall cooling present in a rocket engine, shows a strong influence on the flow field. No significant influence of the lip thickness on the cooling performance is found. Cooling correlations are examined, and a cooling-effectiveness comparison between tangential and wall-normal blowing is performed.
3
Rathore, Nikita, Dinesh Thakur, Nang Elennie Hopak, and Amit Chawla. "Intra-Annual Variation in Leaf Anatomical Traits of an Overwintering Shrub of High Elevations of Himalaya." In Plant Defense Mechanisms [Working Title]. IntechOpen, 2022. http://dx.doi.org/10.5772/intechopen.102016.
Abstract:
Trait variability in response to seasonal variations can be hypothesised as an advantageous strategy for overwintering shrubs. This hypothesis was tested by elucidating patterns of trait variation in an evergreen alpine shrub, Rhododendron anthopogon D. Don. The study site was established at Rohtang (3990 m a.s.l.) in western Himalaya. Its leaves were sampled at 10 time points spanning a period of 1 year (beginning from 22-August-2017 to 14-August-2018) for estimating anatomical traits using light and scanning electron microscopy. The data were analysed using one-way analysis of variance, and the trait-temperature relationships were analysed using linear regression. The results indicated a lower variability in the anatomical traits. A few traits (e.g. cuticle thickness and epidermal scales) were found to be significantly correlated with temperature (p < 0.05). Our analysis revealed increase in cuticle thickness and a decrease in epidermal scales (size) during low-temperature conditions. The lesser variability found in anatomical traits of overwintering shrub could be explained as ‘evolutionary gained adaptive traits’.
4
Baldanza, Angela, Roberto Bizzarri, Annachiara Bartolini, Angela Bertinelli, and Roberto Colacicchi. "The Jurassic structural high of Sasso di Pale (Umbria-Marche Basin, Italy): How a small Apennine structure recorded Early to Middle Jurassic global perturbations." In From the Guajira Desert to the Apennines, and from Mediterranean Microplates to the Mexican Killer Asteroid: Honoring the Career of Walter Alvarez. Geological Society of America, 2022. http://dx.doi.org/10.1130/2022.2557(15).
Abstract:
ABSTRACT The reduced Jurassic sedimentary sequences deposited on a structural high in the Umbria-Marche Apennines, as well their relationships with adjacent expanded basinal sequences, have been reconstructed through detailed, interdisciplinary study of the Sasso di Pale and Monte Serrone areas near Foligno, Italy. The physiographic features of the basin originated in the Early Jurassic (latest early Pliensbachian), when extensional tectonic activity broke up a shallow water platform where the Calcare Massiccio had been deposited, and the area evolved from an edge-stepped structural high to a distally steepened ramp. The biostratigraphic framework of this paper is mainly based on calcareous nannofossils, which are a useful tool for dating condensed Jurassic successions. Although the sections studied have limited thickness and much lateral facies variation, the sedimentary evolution can be traced and interpreted within a wider Jurassic environmental perspective. In the upper Pliensbachian–lower Bajocian interval, local sea-level variations are compatible with the global sea-level curve. Furthermore, some of the characteristic events—such as the Pliensbachian–Toarcian crisis, the Early Toarcian Jenkyns Event, and the Middle Jurassic carbonate crisis—can be recognized. The present study shows how the reconstruction of local paleogeography can fit into a more general framework and how regional and global signals can be recognized even in a small structural high such as the one we have investigated.
5
Al-Juboury, Ali, Mohammed A. Al-Haj, and Aboosh H. Al-Hadidy. "Stylolite in Upper Cretaceous Carbonate Reservoirs from Northwestern Iraq." In Sedimentary Petrology - Implications in Petroleum Industry [Working Title]. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.97527.
Abstract:
Stylolites are commonly observed in the carbonate reservoirs in various oilfield of Iraq including those of upper Cretaceous successions from northwestern Iraq, where they are characterized by stylolite-rich zones in the Cenomanian-early Turonian Gir Bir Formation and to a lesser extent in the Turonian-Santonian Wajna and early Campanian Mushorah formations respectively. The observed stylolites are either large to be identified in the core samples or smaller ones that are well observed in the thin sections and are characterized by variations in amplitude, morphology and accumulated insoluble residues. The recorded stylolites are classified as hummocky, irregular, low and high-amplitudes peaks, and irregular anastomosing stylolites. Stylolites affect the porosity permeability and thickness reduction compaction as the main chemical compaction (pressure solution) that reduce porosity. Whereas, in other places, the stylolites act as seals and stop the upward movement of hydrocarbons. This is also seen for mineralization processes such as silicification that ended near the stylolite surfaces.
6
Kühl, Michael, and Niels Peter Revsbech. "Biogeochemical Microsensors For Boundary Layer Studies." In The Benthic Boundary Layer, 180–210. Oxford University PressNew York, NY, 2001. http://dx.doi.org/10.1093/oso/9780195118810.003.0008.
Abstract:
Abstract Interfacial processes in sediments, biofilms, and other benthic aquatic systems can be strongly affected by the presence of hydrodynamic boundary layers. The boundary layer (BL) can limit mass transfer between the overlying water and the solid matrix, thus affecting biological processes. The BL region adjacent to reactive surfaces that contains significant chemical gradients is known as the diffusive boundary layer (DBL). The DBL thickness is dependent on the flow velocity, surface topography and porosity of the solid matrix, and it ranges from <0.1 mm to several millimeters in thickness (see also chapters 5, 9, 14 and 15). As the interface is approached, mass transfer of solutes in the DBL becomes less dependent on advective motions (turbulence) and increasingly dependent on diffusion. Any net solute consumption or production within the matrix relative to the surrounding water, therefore, leads to the formation of concentration gradients over the DBL as well as within the matrix. The sediment-water interface thus can be the site of steep gradients of physicochemical variables over distances of <0.1 mm, and methods for studying these variables near the interface must resolve variations over very small distances without significant disturbance to these gradients. Noninvasive optical analysis, by direct microscopic observation, analysis of water current with laser-Doppler anemometry, nuclear magnetic resonance imaging (Wieland, 2000) or positron emission tomography (Khalili et al., 1998) fulfills these requirements, but most methods with high spatial resolution are based on microsensors.
7
Verma, Pratibha, and Arpan Deyasi. "Investigating Opto-Electronic Properties of Surface Plasmon Structure for Spectroscopic Applications." In Contemporary Developments in High-Frequency Photonic Devices, 216–76. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8531-2.ch010.
Abstract:
This chapter is proposed with an approach to analyze reflectance as a function of negative index material thickness for different parameters under the surface plasmon condition and extended approach towards the field enhancement of electric field as function of incidence angle and transmittance as function of incidence angle has been analyzed. This chapter can reflect the good comparison between 3 layer medium and n layer medium model. Characteristic impedance of MIM surface plasmon structure is analytically calculated considering the effect of both Faraday inductance and kinetic inductance. Effect of metal layer thickness, insulator thickness, and electron density are tailored to observe the impedance variation with frequency. Wavelength dependence of characteristic impedance and quality factor of MIM (metal-insulator-metal) surface plasmon structure is analyzed. Structural parameters and damping ratio of the structure is tuned within allowable limit to analyze the variation after detailed analytical computation.
8
Kobayashi, Shiro, Soo-Ik Oh, and Taylan Altan. "Sheet-Metal Forming." In Metal Forming and the Finite-Element Method. Oxford University Press, 1989. http://dx.doi.org/10.1093/oso/9780195044027.003.0014.
Abstract:
The stress-state is said to be plane when the direction normal to the plane is a principal stress direction and the magnitude of the stress in this direction is zero. This situation occurs when a sheet is loaded along its edges in the plane of the sheet. In-plane deformation of sheet metal, such as bore expanding and flange-drawing, is an example of plane-stress problems. For out-of-plane deformation of sheet metals, such as punch stretching, sheet bending, and cup drawing, a simple analytical method is the use of membrane theory. This theory neglects stress variations in the thickness direction of a sheet and considers the distribution of stress components only in the plane of the sheet. Thus, the basic formulations for the analysis of both in-plane and out-of-plane deformations contain only the stress components acting in the plane of the sheet. However, the analysis of out-of-plane deformation requires consideration of large deformation, while the infinitesimal theory is applicable for in-plane deformation analysis. Many materials employed in engineering applications possess mechanical properties that are direction-dependent. This property, termed anisotropy, stems from the metallurgical structure of the material, which depends on the nature of alloying elements and the conditions of mechanical and thermal treatments. Metal sheets are usually cold-rolled and possess different properties in the rolled and transverse directions. Therefore, in sheet-metal forming in particular, the effect of anisotropy on the deformation characteristics may be quite appreciable and important. In the past the calculation of the detailed mechanics of large plastic deformation of metal sheets has been achieved with some success by numerical methods. However, without exception, these studies have dealt with deformations that possess a high degree of symmetry, and were concerned with the anisotropy existing only in the direction of sheet thickness (normal anisotropy). Methods that are capable of solving nonaxisymmetric problems in forming of anisotropic sheet metal are still being sought. The finite-element method is one of those methods. It was applied to the elastic-plastic analysis of nonaxisymmetric configurations of sheet stretching with normal anisotropy by Mehta and Kobayashi.
9
Zelt, Fred, Jim Shaulis, and Frank Pazzaglia. "Special geologic features of Ohiopyle State Park, Pennsylvania, USA." In Field Excursions to the Appalachian Plateaus and the Valley and Ridge for GSA Connects 2023, 79–121. Geological Society of America, 2023. http://dx.doi.org/10.1130/2023.0066(03).
Abstract:
ABSTRACT With waterfalls and the deepest gorge in Pennsylvania, Ohiopyle State Park provides opportunities to observe a variety of habitats and three-dimensional (3-D) exposures of the Pennsylvanian sandstone most responsible for shaping Laurel Highlands landscapes. Evidence for the relationship between bedrock, ancient climates, and the landscape can be observed at some of the most scenic natural features of the park: Baughman Rock Overlook, Cucumber Falls, Ohiopyle Falls, Meadow Run Waterslide and Cascades, and Youghiogheny River Entrance Rapid. Channel azimuths and lateral variations in thickness of upper Pottsville fluvial/deltaic sandstone suggest that deposition was influenced by deformation of this part of the Allegheny Plateau during the Alleghanian orogeny. Geologic features of Pottsville sandstone outcrops include a 10-m- (~33-ft-) long Lepidodendron fossil and a 3-D exposure of a meter-high Pennsylvanian subaqueous sand dune and scour pit. Cosmogenic age dating has indicated very slow erosion of hard sandstone in an upland location at Turtlehead Rock and informed estimation of Pleistocene/Holocene waterfall retreat rates of Ohiopyle and Cucumber Falls. Bedrock exposures supporting scour habitats along the Youghiogheny River occur only in a limited area of Youghiogheny Gorge where knickpoint migration and bedrock erosion were relatively recent. Geologic factors, including locations of major tributaries, development of bars that constrict river flow, and proximity of Homewood sandstone outcrops as sources of boulder obstacles in the river, contributed to the class, location, and nature of whitewater rapids in the lower Youghiogheny River.
10
Cãndido, Ruan da Silva, José Henrique da Siva Taveira, Adriana Rodolfo da Costa, Patrícia Costa Silva, Pedro Rogerio Giongo, Josué Gomes Delmond, Alexia Amiluana Sousa Martins, Ana Flávia Alves Ferreira, Carlos Miguel Barbosa Valerio, and Emanuelly Silva Araújo. "Variations in the physical properties of soybeans during the drying process and changes in the classification of soybeans stored with different temperatures and evaluation methodologies." In DEVELOPMENT AND ITS APPLICATIONS IN SCIENTIFIC KNOWLEDGE. Seven Editora, 2023. http://dx.doi.org/10.56238/devopinterscie-236.
Abstract:
The objective of this study was to evaluate the effect of drying at different temperatures on the physical properties of the grains; water content, volumetric contraction, the weight of thousand grains, apparent specific mass, length, width, thickness, circularity, sphericity, and comparison of methodologies of soybeans. To evaluate the physical properties, the soybean grain samples with an initial water content of 19.06% b.u. were subjected to the effects of drying air temperatures heated to 40ºC, 55ºC, 70ºC, and 85ºC. The samples were dried in a conventional natural convection oven until reaching 19% water contents, 17%, 15%, 13%, and 11% b.u. Subsequently, the drying curve of soybeans dried under different temperatures was characterized and the physical properties of an apparent specific mass, the weight of one thousand grains, and volumetric contraction were analyzed. It was noted that the increase in temperature affected the three-dimensional axes of the grains, causing them to lose water to the drying air. However, when these grains are dried at high temperatures spending less time, their characteristics are modified. The weight of the grains and the apparent specific mass decreased with increasing temperature during drying. The circularity, sphericity, and unit volume decreased with the increase in temperature during drying, therefore, it is not possible to use the new proposal of digital methodology instead of manual measurement, since the correlation between the two methodologies is close to zero. For the conditions under which the experiment was carried out, it can be concluded that with the increase in the temperature of the drying air, the grains dry faster, and yet the physical dimensions are more preserved, not being intensely reduced throughout the process.
Conference papers on the topic "High thickness variations":
1
Birnie, Dunbar P., M. Manley, B. J. J. Zelinski, and S. M. Melpolder. "Process-Related Thickness Variations in Spin-On Interference Filters." In Optical Interference Coatings. Washington, D.C.: Optica Publishing Group, 1995. http://dx.doi.org/10.1364/oic.1995.tud3.
Abstract:
Optical interference filters can easily be fabricated from high and low index transparent coatings using a number of different processing routes. One inexpensive method for depositing oxide coatings is through spin-on chemical routes [1-3].
2
Komiyama, Ryohei, Takashi Gonoi, and Toshio Nishizawa. "A Thin Film Multi-Layered SAW Resonator on Sapphire Substrate with High Acoustic Velocity Stability for Film Thickness Variations." In 2023 IEEE International Ultrasonics Symposium (IUS). IEEE, 2023. http://dx.doi.org/10.1109/ius51837.2023.10306382.
3
Chen, Yu, and Jonathan Parker. "The Effect of Ovality and Thickness Variations on Stress Analysis of Tube Bends Under Internal Pressure." In ASME 2012 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/pvp2012-78113.
Abstract:
Corrosion fatigue damage has resulted in the catastrophic failure of several riser and supply tubes in fossil boilers operating under sub-critical conditions. Most of the damage has been found on the neutral axis of tube bends and the damage mechanism was identified as corrosion fatigue. Significant stress concentrations will always be found associated with high tube ovality and significant thickness variations. The purpose of this study is to demonstrate the effect tube bend geometry on the stress distributions developed due to the internal pressure. The work was performed to consider how the stresses present in tube bends vary with ovality and thickness variations (thinning/thickening). Ovality and thickness variations in tube bends, which are generally introduced during the bending process, were modeled into the three-dimensional finite element models (FEM). The finite element models considered five different degrees of ovalization of the cross-section at the center of the bend. For each model the maximum principal stress values and distribution of stresses within tube bends were evaluated. The finite element analysis (FEA) predictions were compared with the actual locations of corrosion damage on the tube bend and reasonably predicted where cracks should be expected to initiate and propagate, and where cracks should not be anticipated.
4
Arthurs, David, and Samir Ziada. "The Effect of Fluid-Resonant Coupling in High-Speed Impinging Planar Jet Flows." In ASME 2013 Pressure Vessels and Piping Conference. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/pvp2013-97141.
Abstract:
This study investigates the effect of fluid-resonant coupling, i.e. the coupling between unstable modes of an impinging jet with resonant acoustic modes occurring between the nozzle and the impingement surface, on the self-excited oscillations of high-speed impinging planar jet. In order to investigate this phenomenon, a series of experiments have been performed using a high-speed impinging planar jet with varying nozzle thickness (h) and impingement distance (xo), for a single Mach number in the compressible flow regime. The test results reveal that the jet oscillation is controlled by a fluid-dynamic mechanism for small impingement distances, where the unstable mode of the jet is controlled by the impingement ratio. At larger impingement distances, the response is dominated by a fluid-resonant mechanism, in which the various hydrodynamic modes of the jet couple with different resonant acoustic modes occurring between the nozzle and the impingement surface. Within the fluid-resonant regime the system produces acoustic tones that are excited predominantly as a function of the impingement distance, with the nozzle thickness and impingement ratio having only minor effects on the tone frequency. Flow visualization images show that the same unstable mode is excited for multiple nozzle thicknesses at a constant impingement distance, despite the wide variations in associated impingement ratio.
5
Kainat, Muntaseer, Samer Adeeb, J. J. Roger Cheng, James Ferguson, and Michael Martens. "Identifying Initial Imperfection Patterns of Energy Pipes Using a 3D Laser Scanner." In 2012 9th International Pipeline Conference. American Society of Mechanical Engineers, 2012. http://dx.doi.org/10.1115/ipc2012-90201.
Abstract:
Measurement of initial imperfections of energy pipes and incorporating them in analytical models has been a major focus of research in the pipeline industry as well as at the University of Alberta. Researchers at the University of Alberta have devised various techniques to measure initial imperfection of pipes prior to testing. The analytical imperfection models developed based on these techniques have proven to be effective in predicting pipe behavior. These techniques, however, are time consuming, error prone to some extent, and yield limited data, in addition to their limitations regarding the size of the pipes that can be measured. The objective of the current study is to overcome the limitations of the previous measurement techniques by utilizing advanced surface profiling technology. A high accuracy 3D laser scanner is used to create three dimensional models of energy pipes. Commercially available reverse engineering and inspection software is used to measure the different geometric attributes of the pipes that are of interest. This new technique enables us to overcome the previous limitations by acquiring data in the field at a faster rate and creating high resolution point clouds. The actual pipe surfaces are compared with the model of a perfect cylinder of uniform nominal diameter. It is possible to locate the axes of the scanned pipes and use these axes as references for measurements. Outer diameter variation, thickness variations, weld geometry variations and deviations from a perfect cylinder are measured. Results indicate that the deviations from a perfect cylinder can be used to describe the pattern of radii variations around the perimeter of the pipes. When described with respect to the seam weld location, distinct patterns of radii variations were identified. Thickness variations showed identical behavior in all the pipes when viewed with respect to the seam weld location.
6
Lin, Min, and Yang Liu. "Accurate Thickness Inversion of Corrosion Using A1 Lamb Wave." In 2021 48th Annual Review of Progress in Quantitative Nondestructive Evaluation. American Society of Mechanical Engineers, 2021. http://dx.doi.org/10.1115/qnde2021-75313.
Abstract:
Abstract Corrosion is one of the most critical issues in the oil and gas industry, leading to severe environmental and economic problems. Due to the high cost and serious safety risk of corrosion, it is essential to improve current corrosion testing techniques to detect corrosion damages at an early stage. Guided wave tomography (GWT) demonstrates its great potential to inspect and quantify the corrosion damage. GWT is capable of determining the residual life of corrosion structures by quantifying the remaining wall thickness. In this paper, an accurate guided wave tomography technique incorporating full waveform inversion (FWI) and higher-order Lamb waves (A1 mode) is presented for plate-like structures, which is able to get high-resolution reconstruction results. The technique consists of three steps: forward modeling, velocity inversion and thickness reconstruction. The forward modeling is computed by solving the elastic full-wave equations in 2-D time domain by using the finite difference method. High-resolution phase velocity inversion can then be obtained by minimizing the waveform misfit function between simulated and recorded data using a second order optimization method, which updates the velocity model from low to high frequencies iteratively. Finally, the velocity variations can be transformed into depth profiles by using the dispersive characteristics of ultrasonic guided waves; therefore, the thickness reconstruction can be obtained. The numerical simulations are performed on an aluminum plate with a complicated corrosion defect. By comparing the thickness reconstruction maps using both A1 and A0 modes, the results demonstrate that FWI with A1 mode can achieve significantly better resolution of corrosion imaging than that with A0 mode.
7
Jagtap, Aditya, Faiz Khan, Harsh Shah, and Shekhar Malani. "Effect of Busbar Design on the Thermal Performance of Battery Packs." In Symposium on International Automotive Technology. 400 Commonwealth Drive, Warrendale, PA, United States: SAE International, 2024. http://dx.doi.org/10.4271/2024-26-0135.
Abstract:
<div class="section abstract"><div class="htmlview paragraph">Li-ion batteries face challenges that are not usually present with other chemistries is cell balancing. If a high imbalance occurs within a parallel circuit, possibly because of poor cell - grading or due to temperature localization, the adjacent cells will charge the unbalanced cell and it may be possible that the imbalance never completely fades away and the other cells also end up unbalanced. One of the key solutions to maintaining cell balance is to ensure that all cells within a battery pack are kept at a uniform temperature. This requires careful thermal management, which can be achieved through a combination of conduction and convection circuits. In this paper, a 1D-3D simulation study has been performed on a 12V 4s-4p pack by varying the thickness of HV busbars and temperature localization effects and temperature uniformity has been observed. The holder has 16 cells with a 4×4 grid pattern, each cell has a diameter of 18 mm and a length of 65 mm. The cells are connected in series using nickel busbars using a thickness of 0.25 mm and width of 28 mm which runs along the top and bottom of the cells. Cells are connected to HV busbars at the ends of cell grids. The HV busbars are 0.25 mm in thickness and 180 mm in length under natural convection environment and for variations. A pure copper strip has been used at different locations in other variations on nickel busbars to observe the effect of temperature localization. The output temperature contours under various loadings have been studied and the temperature of each cell in the matrix has been plotted to observe the variation and non-uniformity of temperature among cells for different busbar thicknesses.</div></div>
8
Al Araimi, A., H. Al Yahyai, and A. Taher. "Optimizing Well Placement in Heterogenous Carbonate Reservoir Utilizing a New Generation of High Definition Mapping Tool." In SPE Conference at Oman Petroleum & Energy Show. SPE, 2024. http://dx.doi.org/10.2118/218651-ms.
Abstract:
Abstract Field development plans and oil recovery can be significantly enhanced by the full understanding of the geological structure, petrophysical properties and reservoir behavior. Detailed subsurface understanding can depict strategies for reservoir and field development. Building a detailed picture of the reservoir requires a combination of measurements and data acquisition processes usually starting with seismic data to build a geological model which is refined during drilling operations with a combination of logging while drilling (LWD) and reservoir mapping sensors. Conventional LWD sensors usually measure formation properties around the well trajectory, Deep azimuthal electromagnetic (EM) tools are often used to map boundaries further away from the wellbore to improve well placement. The resistivity of the surrounding formation and resistivity contrast with the adjacent layers are two critical factors that influence the depth of detection and ability to map multiple layers. As the resistivity contrast decreases, it becomes more difficult to identify boundaries at a distance. A Deep Azimuthal EM tool with enhanced sensitivity to resistivity variations was deployed along with a mapping inversion algorithm in the case study. In addition to utilizing density and neutron tools, to provide a detailed picture of the reservoir and refine the geological interpretation near well-bore. A case study from the North of Oman where a carbonate reservoir with anticipated thickness variation and variable reservoir quality, overlain by shale identified from offset data was selected for the deployment of a high-definition multi-layer inversion mapping tool. The varying thickness of the carbonate target and the small contrast in resistivity laterally towards the toe with the shale above imposed additional challenges for conventional deep resistivity tools due to their limited depth of detection and, were anticipated as being a challenge to the well placement operation, limiting the depth of investigation and the ability to detect the critical boundary and ensure there was no exit in areas of thinning. The Realtime inversion output showed the Resistivity degradation across the lateral section ranging from 12 ohm-m to 2.5 ohm-m, the thickness of the reservoir showed substantial variation varying from 32ft at heel to 8ft at toe. The continuous detection of bed boundaries along with lateral deterioration of resistivity provided a detailed view of the reservoir thickness and dip variation to optimize well placement decisions A novel approach for utilizing a new generation of high-definition multi-layer inversion mapping tool, the successful mapping of the boundaries in low resistivity contrasts expands the environments in which the technology can be confidently deployed and ensure optimum well placement with increased reservoir understanding.
9
Gao, Huang, and Gary J. Cheng. "Laser Induced High-Strain-Rate Superplastic 3D Micro-Forming of Metallic Thin Film." In ASME 2009 International Manufacturing Science and Engineering Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/msec2009-84087.
Abstract:
Microforming of metals has always been a challenge because of the limited formability of metals at micro-scales. This paper investigates an innovative micro-forming technique: Laser Dynamic Forming (LDF), which induces 3-D superplastic forming in metal thin films. This forming process proceeds in a sequence of laser irradiation of ablative coating, ionization, shockwave generation and propagation in metal thin films, and conformation of metal thin films to the shape of micro/nanoscale molds. Because the deformation proceeds at ultrahigh strain rate, it is found that materials experience superplastic deformation at microscales. In this paper, experiments are carried out to understand the deformation characteristics of LDF. The shapes of the formed samples are characterized by scanning electron microscopy (SEM) and optical profilometer. The thickness variations are characterized by slicing the cross section using focused ion beam (FIB). The magnitude of deformation depth in LDF is determined primarily by three critical factors: thin film thickness, geometry of molds, and laser intensity. The relationships between laser intensity, film thickness, and mold size are explored in process maps to find out suitable processing conditions of LDF. Nanoindentation testings are conducted to show that the mechanical properties (hardness and yield strength) are increased significantly after LDF.
10
Mollenhauer, David, Daniel Post, and Kenneth Reifsnider. "Moiré Interferometry Measurements of Interlaminar Deformation at an Open Hole in Laminated Composite Materials." In ASME 1998 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 1998. http://dx.doi.org/10.1115/imece1998-1196.
Abstract:
Abstract The deformation on cylindrical surfaces of holes in tensile-loaded laminated composite specimens was measured using new moiré interferometry techniques. Two composite tensile specimens, fabricated from IM7/5250-4 pre-preg with ply layups of [0°4/90°4]3s and [+30°2/-30°2/90°4]3s, were examined using the newly developed moiré interferometry techniques. Circumferential and thickness direction displacement fringe patterns (each 3° wide) were assembled into 90°-wide mosaics around the hole periphery for both composite specimens. Distributions of strain were calculated with high confidence on a sub-ply basis at select angular locations. Measured strain behavior was complex and displayed ply-by-ply treands. Large ply-related variations in the circumferential strain were observed at certain angular locations around the periphery of the holes in both composites. Extremely large ply-by-ply variations of the shear strain were also documented in both composites. Peak values of shear strain approached 30 times the applied far-field axial strain. Post-loaded viscoelastic shearing strains were recorded that were associated with the regions of large load-induced shearing strains. Large ply-group related variations in the thickness direction strain were observed in the [+30°2/-30°2/90°4]3s specimen. An important large-scale trend was observed where the thickness direction strain tended to be more tensile near the outside faces of the laminate than near the mid-ply region. The measured strains were compared with the three-dimensional analysis technique known as Spline Variational Elastic Laminate Technology (SVELT), resulting in a very close match and corroborating the usefulness of SVELT.
Reports on the topic "High thickness variations":
1
Groeneveld. L51663 Seam-Weld Quality of Modern ERW-HFI Pipe. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), September 1991. http://dx.doi.org/10.55274/r0010609.
Abstract:
Major advances have been made in recent years in the production of electric resistance-welded (ERW) and high-frequency induction (HFI)-welded line pipe, particularly in the area of automated process control procedures designed to ensure uniform, high-quality seam welds. ERW/HFI pipe produced from microalloyed, controlled-rolled steels can be obtained in larger diameters and heavier wall thicknesses than were formerly available, and with reportedly excellent seam-weld quality as well as pipe body properties. Thus, it is feasible to consider the application of ERW/HFI pipe in a number of additional applications in gas-transmission lines. The lower cost of the ERW/HFI pipe compared with double submerged arc welded (DSAW) pipe of comparable size has resulted in increased interest in the greater use of this product. This work was undertaken to determine whether the seam weld quality of modern ERW/HFI pipe has been improved to justify more widespread use, particularly in critical locations, with resultant reductions in construction costs. The report describes the test protocol and results from six samples ranging from X60 through X70 pipe provided by PRCI member companies. Variations in weld zone properties in one of the samples are reviewed and attributed in some detail.
2
Lacerda Silva, P., G. R. Chalmers, A. M. M. Bustin, and R. M. Bustin. Gas geochemistry and the origins of H2S in the Montney Formation. Natural Resources Canada/CMSS/Information Management, 2022. http://dx.doi.org/10.4095/329794.
Abstract:
The geology of the Montney Formation and the geochemistry of its produced fluids, including nonhydrocarbon gases such as hydrogen sulfide were investigated for both Alberta and BC play areas. Key parameters for understanding a complex petroleum system like the Montney play include changes in thickness, depth of burial, mass balance calculations, timing and magnitudes of paleotemperature exposure, as well as kerogen concentration and types to determine the distribution of hydrocarbon composition, H2S concentrations and CO2 concentrations. Results show that there is first-, second- and third- order variations in the maturation patterns that impact the hydrocarbon composition. Isomer ratio calculations for butane and propane, in combination with excess methane estimation from produced fluids, are powerful tools to highlight effects of migration in the hydrocarbon distribution. The present-day distribution of hydrocarbons is a result of fluid mixing between hydrocarbons generated in-situ with shorter-chained hydrocarbons (i.e., methane) migrated from deeper, more mature areas proximal to the deformation front, along structural elements like the Fort St. John Graben, as well as through areas of lithology with higher permeability. The BC Montney play appears to have hydrocarbon composition that reflects a larger contribution from in-situ generation, while the Montney play in Alberta has a higher proportion of its hydrocarbon volumes from migrated hydrocarbons. Hydrogen sulphide is observed to be laterally discontinuous and found in discrete zones or pockets. The locations of higher concentrations of hydrogen sulphide do not align with the sulphate-rich facies of the Charlie Lake Formation but can be seen to underlie areas of higher sulphate ion concentrations in the formation water. There is some alignment between CO2 and H2S, particularly south of Dawson Creek; however, the cross-plot of CO2 and H2S illustrates some deviation away from any correlation and there must be other processes at play (i.e., decomposition of kerogen or carbonate dissolution). The sources of sulphur in the produced H2S were investigated through isotopic analyses coupled with scanning electron microscopy, energy dispersive spectroscopy, and mineralogy by X-ray diffraction. The Montney Formation in BC can contain small discrete amounts of sulphur in the form of anhydrite as shown by XRD and SEM-EDX results. Sulphur isotopic analyses indicate that the most likely source of sulphur is from Triassic rocks, in particular, the Charlie Lake Formation, due to its close proximity, its high concentration of anhydrite (18-42%), and the evidence that dissolved sulphate ions migrated within the groundwater in fractures and transported anhydrite into the Halfway Formation and into the Montney Formation. The isotopic signature shows the sulphur isotopic ratio of the anhydrite in the Montney Formation is in the same range as the sulphur within the H2S gas and is a lighter ratio than what is found in Devonian anhydrite and H2S gas. This integrated study contributes to a better understanding of the hydrocarbon system for enhancing the efficiency of and optimizing the planning of drilling and production operations. Operators in BC should include mapping of the Charlie Lake evaporites and structural elements, three-dimensional seismic and sulphate ion concentrations in the connate water, when planning wells, in order to reduce the risk of encountering unexpected souring.
3
Holdren. L51934 Feasibility of Nd-Yag Laser-Arc Welding Processes for Girth Welding. Chantilly, Virginia: Pipeline Research Council International, Inc. (PRCI), December 2002. http://dx.doi.org/10.55274/r0010632.
Abstract:
Laser beam welding (LBW) has become standard in many high-production and critical applications where the return on investment can be quickly realized due to the process' inherent efficiency in terms of weld penetration and travel speed. Also, some promising work has been done internationally related to the use of hybrid laser/arc welding (HLAW) for some applications (primarily shipbuilding), so this process variation was also included in the study. However, virtually all of the current LBW or HLAW applications are considered 'factory' applications, and therefore do not represent the logistical challenge associated with bringing laser technology to on or offshore pipeline welding operations. This project was aimed at studying the feasibility of overcoming those logistical challenges in order to realize the potential cost savings of applying this high production process. This study was limited to the application of Nd:YAG lasers (which can be delivered via fiber-optic cable) since the logistics of incorporating higher power CO2 lasers was felt to be impractical. The focus of the project was to study the potential productivity of the LBW and HLAW processes in terms of the thickness of material that could be welded in a single pass at a given travel speed. Additionally, the robustness of the process was determined using weld joints with less than ideal fit up. Potential feasibility of the processes were then determined by considering both the practical aspects of their application as well as the economic justification.
4
Sun, S., F. R. Brunton, T. R. Carter, J. R. Clarke, H. A J Russell, K. Yeung, A. Cachunjua, and J. Jin. Porosity and permeability variations in the Silurian Lockport Group and A-1 carbonate unit, southwestern Ontario. Natural Resources Canada/CMSS/Information Management, 2023. http://dx.doi.org/10.4095/331902.
Abstract:
This is the first regional porosity/permeability study to incorporate petroleum industry laboratory core analyses submitted to the Ontario government and managed by Ontario's Oil Gas and Salt Resources Library. This study comprises 11,759 analyses for the Early Silurian Lockport Group of southwestern Ontario from 150 drill cores. The Lockport Group consists of a cyclic succession of dolostones and minor limestones comprising, in ascending order: Gasport, Goat Island, Eramosa, and Guelph formations. This stacked carbonate succession was deposited on an eastward-deepening carbonate ramp, extending from Michigan, through southwestern Ontario, to Ohio, Pennsylvania and New York. It is overlain disconformably by restricted marine carbonates, evaporites and mixed shales of the Salina Group, whereas unconformably underlain by one of four formations that include, the Lions Head (a stratigraphic equivalent of part of the Rochester), DeCew, Rochester and Irondequoit. To ensure appropriate stratigraphic assignment of the laboratory test intervals, a quality assurance/quality control review on formational tops was carried out on the 150 cores that were tested. This regional subsurface work resulted in the reassignment of 846 formation tops that were verified by examination of drill core, drill cuttings, and geophysical well data including gamma-ray, neutron and density logs. Core analysis datasets have been validated by summarizing laboratory protocols and standards and reconciling data fields in the core analysis database with auxiliary data, including geophysical logs, thin sections, and core examinaion. This auxiliary data was then used to identify data outliers to update the core analysis database. The measurements of porosity and permeability were then assigned a formation rank plotted on a subregional scale. Average porosity and permeability values have been divided into statistical populations for each formation assigned by three depositional realms. The southwestern Ontario study area has been divided into three paleogeographic settings, based on distinctive lithofacies that correspond to different carbonate depositional regimes and regions of paleokarstification. From northwest to southeast, the lithofacies reflect an inner to outer carbonate ramp setting designated as area 1-3 from northwest to southeast. Area 1 is the inter-pinnacle karst region and includes some of thepinnacle structures within the Lockport Group. This region has the most significant paleokarstification of the upper Lockport Group (Guelph and Goat Island formations) and overlying Salina Group A-unit. Area 2 has rare pinnacle structures, where no porosity/permeability core analyses data are available. Area 3 is the middle to outer portion of the Lockport carbonate ramp, with local development of reef mound phases in the lower Goat Island and Gasport formations. The porosity and permeability variability corresponds with areal distribution of paleokarstification and resulting diagenetic phases in Area 1, and lithofacies variations and temporal/spatial history of karstification in Area 3. Higher porosity and permeability generally coincide with greater thicknesses of the oil and gas reservoir within pinnacles in Area 1 and reef mound phases of Lockport Group and lower Salina Group A-1 Carbonate in Area 3. Within inter-pinnacle karst regions in Area 1, average porosity for each formation is consistently high with little variations. In Area 3, a general increase of porosity and permeability towards the southeast corresponds with lithofacies ranging from restricted lagoonal/platform interior deposits to carbonate bank deposits with local development of reef mound phases in the Gasport and Goat Island formations. There has been significant erosion and karstification within and at the tops of these pinnacles, resulting in higher porosity and permeability of the Guelph and upper Goat Island formations, and the overlying Salina Group A-1 unit. Paleokarstic events have enhanced various porosity types, including intercrystalline, moldic, irregular and fenestral vugs, and cavities.