bluuebunny/crossref_metadata_2025 huggingface dataset:
Pemahaman Konsep Matematika Ditinjau Dari Gaya Belajar Dan Kecerdasan Intelektual
Authors: Firdaus Ridwan Awalian
Published: April 2023

Tujuan dari penelitian ini adalah mengetahui masing-masing pengaruh gaya belajar dan kecerdasan intelektual terhadap pemahaman konsep matematika siswa pada kelas 10 SMA di Kota bogor. Selain itu pengaruh interaksi gaya belajar dan kecerdasan intelektual terhadap pemahaman konsep matematika siswa. Metode penelitian yang digunakan adalah expost facto. Sampel berukuran 123 siswa yang terdiri atas 32 siswa visual, 54 siswa auditori dan 37 siswa kinestetik. Teknik sampling yang digunakan yaitu cluster sampling. Pengumpulan data dilaksanakan dengan pemberian tes pemahaman konsep matematika dan penyebaran angket gaya belajar siswa. Hasil penelitian menunjukkan: 1).Terdapat pengaruh yang tidak signifikan gaya belajar terhadap pemahaman konsep matematika. Hal ini dibuktikan dengan sig.=0,573 (>0,05) dan FH=0,559. Jadi tidak ada perbedaan pemahaman konsep matematika antara kelompok siswa dengan gaya belajar visual, auditori maupun kinestetik. 2).Terdapat pengaruh yang signifikan kecerdasan intelektual terhadap pemahaman konsep matematika. Hal ini dibuktikan dengan sig.= 0,00(< 0,05) dan FH= 23,34. Jadi ada perbedaan pemahaman konsep matematika antara kelompok siswa dengan kecerdasan intelektual tinggi dengan kecerdasan intelektual rendah. 3). Terdapat pengaruh interaktif yang tidak signifikan gaya belajar  dan kecerdasan intelektual terhadap pemahaman konsep matematika. Hal tersebut dibuktikan dengan sig.=0,821(>0,05) dan FH=0,197 sehingga tidak diperlukan uji lanjut.
Factors Influencing Procurement Performance: Moderating Role of Ethical Leadership: A Case of Home Textile Industry of Pakistan
Authors: Zafar Toqeer Zafar , Chughtai Muhammad Ahsan , Ihsan Farooq , Ahsan Qurratulain
Published: April 2023

Procurement performance has been under reflection for past few decades due to its ever-swap measurements with the passage of time. Resource based theory explained the communication and relationship of Procurement Planning, Staff Competency, Procurement Procedures, Resource allocation along with moderator of Ethical Leadership on Procurement Performance. In this study, these variables were examined for the Home Textile Industry of Pakistan. The data was collected from 402 respondents working in Procurement sector of home textile industry of Pakistan. The data gathered was further analyzed through multiple regressions in SPSS. The results indicate that Procurement Planning, Staff Competency, Procurement Procedures, Resource allocation along with moderator of Ethical Leadership has positive impact on Procurement Performance. Practical and theoretical implications have also been discussed.
قاعدة "الضرر يزال" وتطبيقاتها من خلال فتاوى الشاطبي
Authors: أبوعطاء الله عائشة
Published: April 2023

هدفت الدراسة إلى بيان أن القواعد الفقهية علم كغيره من علوم الشريعة الإسلامية، بل هو العلم الذي لا ينضب معينه، وإن التعمق فيه يفسح المجال للفقيه المجتهد لاستنباط الأحكام المسايرة لكل عصر، المتجددة في الزمان والمكان، كما تهدف الدراسة أيضا لبيان جهود الشاطبي في الإفتاء، فرغم اعتماده على النص من القرآن والسنة، والتزامه بالمشهور من المذهب المالكي إلا أن ذلك لم يمنعه من الاجتهاد المبني على النظر والتعليل والتوجيه فيما لا يجد نصا فيه، ولا قولا لأحد من الفقهاء، كما اعتمد في فتاويه على مقاصد الشريعة الإسلامية المبنية على جلب المصالح ودرء المفاسد وإزالة الضرر الذي قد يلحق بالمستفتي، فكانت منهجيته تقوم على اعتبار الدليل الجزئي دون إغفال القواعد الفقهية القائمة على إقامة مصالح المكلفين الدنيوية والأخروية.

استخدمت الباحثة المنهجين الاستقرائي والتحليلي. وتوصلت الدراسات إلى مجموعة من النتائج اهمها: أن الشاطبي اهتم بالتطبيق الفعلي لقواعد الفقه وخاصة قاعدة: الضرر يزال وفروعها الفقهية، فكان حريصا على أن تظل هذه القواعد حية مطبقة في ميادينها، وخاصة ميدان الإفتاء، لارتباطه الوثيق بحياة الناس. وأوصت الدراسة بمجموعة من التوصيات أهمها: ضرورة زيادة بحث عن قاعدة الضرر يزال في فتاوى الشاطبي لإعادة قراءة هذه الفتاوى وجعلها مسايرة لكل الأزمنة.
تطوير تشكيل وأدوار مجالس أولياء أمور طلبة المدارس بسلطنة عُمان في ضوء نماذج بعض الدول
Authors: ابراهيم حسام الدين السيد محمد , المرزوقي أحمد بن سعيد بن عبدالله
Published: April 2023

هدفت الدراسة الحالية إلى تطوير تشكيل وأدوار مجالس أولياء أمور طلبة المدارس بسلطنة عُمان في ضوء نماذج بعض الدول، واستخدمت الدراسة المنهج الوصفي، كما استخدمت تحليل الوثائق في جمع البيانات والمعلومات. وتوصلت الدراسة إلى أن تشكيل مجالس أولياء أمور طلبة المدارس في بعض دول العالم يتضمن أربعة فئات هي: ممثلين عن أولياء الأمور، والمجتمع المحلي، والعاملين بالمدرسة، والطلبة، كما تقوم هذه المجالس بتشكيل لجان لتساعده في أداء أدواره، كما بينت النتائج أن مجالس أولياء أمور طلبة المدارس في بعض دول العالم يعتمدعملها على وجود أدوار محددة للأعضاء مثل: دور الرئيس، ونائب الرئيس، والسكرتير، وأمين الصندوق؛ بالإضافة إلى قيام المجالس بأدوار متعددة في مجالات التخطيط الاستراتيجي، والتمويل، وتقويم الأداء المدرسي، وبناء شراكات فعالة مع أولياء الأمور والمجتمع المحلي، كما توصلت النتائج إلى أن مجالس أولياء أمور طلبة المدارس بسلطنة عُمان لا يتضمن في تشكيلها ممثلين عن المجتمع المحلي والطلبة، ولا توجد أدوار محددة للأعضاء، ولا توجد لجان فرعية يتم تشكيلها، بالإضافة إلى غياب بعض المهام والمسؤوليات عن عمل المجلس مثل: التخطيط الاستراتيجي، وتقويم الأداء المدرسي.
دور العلماء المسلمين في تطوير الحركة الفكرية خلال العهد الإيلخاني
Authors: السعدي ناجي طالب هاشم
Published: April 2023

تعد فترة ما بعد سقوط بغداد على يد المغول (بعد عام 656هـ) من الفترات المهمة والحرجة في التاريخ الإسلامي، إذ إن هذه المدة لم تكن من الفترات المظلمة كما يصفها بعض المؤرخين، حيث يصفها البعض بفترة جمود وركود، وما تم ملاحظته في ثنايا هذا الأمر، خلاف ذلك.  ورغم صعوبة هذه الفترة الزمنية، والفوضى السياسية التي مرت بها، هنالك أنشطة فكرية وأديبة، إذ مارس العلماء دورهم في أداء مهامهم العلمية في العهد الإيلخاني، وبهذا كان تطورًا كبيرًا في الحركة العلمية في العراق والمشرق الإسلامي، إضافة إلى دور العلماء في تطور الحياة الفكرية وكذلك ظهور عدد من المدارس المتعلقة بهذا الشأن. وتوصلت الدراسة إلى مجموعة من النتائج أبرزها: لوحظ أن هناك دور كبير لعلماء الحلة في تطوير الحركة الفكرية من خلال الوفود العلمية التي قابلت هولاكو من الحفاظ على مدينتهم ومنهم سديد الدين الحلي، وابن إدريس الحلي، وابن نما، وفخر المحققين الحسن بن يوسف بن علي بن المطهر الأسدي، وعند مرافقة نصير الدين الطوسي لهولاكو عند غزوة بغداد، فقد جمع الطوسي أربعمائة ألف مجلد في بغداد.
المظهر التناصي في قصيدة الحكاية عند الشاعر حسب الشيخ جعفر
Authors: نعيمة حميد يعكوب , رسن اقبال حسين
Published: April 2023

هدفت الدراسة الى إبراز المظهر التناصي في القصائد الحكائية عند الشاعر حسب الشيخ جعفر، ولتحقيق هدف هذه الدراسة فقد استخدمت الباحثة المنهج التحليلي وتوصلت الدراسة الى مجموعة من النتائج أبرزها: إن قصيدة الحكاية في شعر حسب الشيخ جعفر شهدت تناصاً مع عدة مصادر تنوعت بين الدينية والتراثية والأدبية، وإن هذه التناصات هي حصيلة قراءات الشاعر والرصيد الثقافي الذي يمتلكه، وقد اغنى به نصوصه الشعرية. وأوصت الدراسة بمجموعة من التوصيات أبرزها: ضرورة اجراء دراسات للتناص في قصيدة الحكاية، وتسليط الضوء على دوره في تشكيل قصيد الحكاية شكلا ومضموناً، وكذلك ضرورة تسليط الضوء من قبل الباحثين والدارسين على المرجعيات ومدى هيمنتها على الخطابات الأدبية.
التنظيم التقليدي للمجال الفلاحي بالأطلس الكبير الغربي: بين هاجس الاستجابة للحاجات الاقتصادية ورهان استدامة الموارد الإيكولوجية
Authors: لحسن الفارسي مولاي
Published: April 2023

وضع المجتمع الجبلي بالأطلس الكبير الغربي تنظيما مجاليا تحقق في إطاره نوع من التوازن، وذلك باستغلال أمثل للموارد المتوفرة بالمحاط كوحدة مجالية تبرز، بجلاء، في تنظيمها مدى حرص الساكنة على تحقيق تكافؤ بين الخصائص الإيكولوجية والأنشطة الاقتصادية والحاجات البشرية، مستثمرة في ذلك العديد من المعارف الزراعية والرعوية المتوارثة.  وانطلاقا من ذلك، نجد أن المحاط ينتظم وفق ثالوث الزراعة والرعي والسكن، وبشكل يراعي استدامة الموارد المحدودة. غير أن التحولات العميقة التي أضحى يشهدها هذا المجال، خاصة مع توغل أنشطة غير فلاحية في مقدمتها السياحة، خلخلت التنظيم التقليدي الذي استجاب لأهداف جماعية مشتركة، وظهرت محددات أخرى لتنظيم المجال ذات أهداف أكثر فردانية ورِبحية.
In-situ computed tomography investigation of the compression behaviour of strut, and periodic surface lattices
Authors:   Örebro University, Jansson Anton ,   Örebro University, Pejryd Lars
Published: April 2023

In this work the effects of fabrication errors in the Body Centered Cubic strut lattice, and the periodic surface lattice Schwarz Diamond has been investigated. The lattices were both fabricated as-is and with induced errors to evaluate the lattices response to fabrication errors. The behaviour of the lattices were studied using compression test and in-situ computed tomography investigation. The results show that the Schwarz Diamond lattices in general are stronger than the Body Centered Cubic lattices in all of the measured aspects. Often up to five times stronger. It was also found that the elastic behaviour of the Schwarz Diamond lattices were mainly unaffected by fabrication errors while the Body Centered Cubic lattices experienced severe losses in performance. The behaviour of the lattices under compression could be followed using computed tomography which aided in the understanding of their behaviour.
Error Investigations for a CT and Additive Manufacturing based Reverse Engineering Workflow
Authors:   Siemens AG,  Corporate Technology (CT), Bauer Fabian ,   Siemens Healthineers, Schrapp Michael ,   Siemens Power Generation Services,, Szijarto Janos
Published: April 2023

A typically occurring task when maintaining gas turbines is the replacement of broken or worn out turbine blades. In order to shorten costly downtimes, it is essential to provide spare parts with minimal lead time; this can turn out problematic in particular for older devices for which blueprints or type designations are not readily available. To overcome this limitation, reverse engineering (RE) methods can provide a remedy, since a geometrical representation of the piece can be obtained at short notice. Due to advances in additive manufacturing (AM) based production, it is also possible to print complex shapes with little additional effort. We present a framework that uses reverse engineering based on Computed Tomography (CT) and optical scanning to obtain the geometry of an AM-printed turbine blade test part and produces a duplicate thereof via the same fabrication technique. To verify the feasibility of the applied RE and manufacturing methods in practice, aberration of both procedures were investigated separately. Combining the results allowed us to review the replicated spare part for geometrical conformance with both, the original turbine blade and the initial design for the part. For this purpose we rely on a simplified approach based on standard deviation and shift of the mean value of error distributions that are obtained by comparing two known geometries to one another. We found that our workflow is capable of deriving the original part’s shape with adequate accuracy and offers the capability for obtaining a good baseline geometry that can be used for further treatment. The framework used is also able to provide meaningful information concerning manufacturing and imaging quality and quantify occurring aberrations of the workpiece. The replica itself exhibits acceptable geometrical deviations for actual productive service when compared to the initial design as well as the original part.
An attempt to detect anomalies in CT-data of car body parts using machine learning algorithms
Authors:   BMW AG, Schromm Thomas ,   Technical University of Munich (TUM), Diewald Fabian ,   Technical University of Munich (TUM), Grosse Christian U.
Published: April 2023

Industries, which produce hundreds of terabyte of CT data per year, demand automated evaluation approaches. This work provides a first glance of an attempt to automatically detect and characterize possible defects and/or anomalies which formed during common joining processes. We investigated a standard riveting process with respect to the resulting final head height of steel selfpiercing half-hollow rivets. The methods include conventional image processing algorithms, like edge-detection, thresholding and principle component analysis (PCA) which were used to pre-process the CT data. In order to automatically evaluate the reconstructed volumes, which contained several of the aforementioned rivets, we compared the performance of different, publicly available, convolutional neural network (CNN) architectures. Furthermore, we investigated the impact of data augmentation and showed by means of a k-fold cross-validation that the training data causes no overfitting of the network. The obtained results suggest that an automated evaluation of the generated computed tomography scans, with regard to a rivet’s final head height, is feasible. However, in order to increase the network’s reliability and accuracy, the amount of training data needs to be further enlarged and diversified.
Virtual qualification of novel heat exchanger components with the image-based finite element method
Authors:   Swansea Institute, Evans Llion M. ,   Culham Science Centre, Minniti Triestino ,   Culham Science Centre, Barrett Tom ,   Max-Planck-Institut für Plasmaphysik, Von Müller Alexander ,   University of Manchester, Margetts Lee
Published: April 2023

This paper presents the application of the image-based finite element method (IBFEM) to quantify the impact of micro-structure caused by manufacturing processes on the performance of fusion energy heat exchangers. The components, containing tungsten, were imaged with high-power lab-based X-ray CT and neutron CT. Volume data was converted into part-specific IBFEM meshes using the software ScanIP. The open source software ParaFEM was used to simulate the microstructurally faithful models using boundary conditions to simulate the extreme environment within a nuclear fusion reactor. By comparison with design-based simulations the impact of minor deviations from the design introduced during manufacturing were estimated. By digitally testing ‘real’ components, results can be interrogated through the sample’s full volume. This provides more sophisticated information than pass/fail experimental tests which can be used to rate components in a manner similar to material purity for optimised usage.
Comparison of different measures for the single point uncertainty in industrial X-ray computed tomography
Authors:   University of Erlangen-Nürnberg (FAU), Müller Andreas Michael ,   University of Erlangen-Nürnberg (FAU), Hausotte Tino
Published: April 2023

The concept of single point uncertainty describes a methodology to statistically evaluate the local measurement results of a
measurement series with respect to the associated reference geometry. The single point uncertainties can be used as local quality
parameters or weighting factors in subsequent processing of a measurement and can therefore have a significant impact on the
final measurement results. The core routine used in former work at the Institute of Manufacturing Metrology, which is based on
ray-triangle intersection tests, provided accurate results under most conditions. Nevertheless, some disadvantages were observed,
including the very high computational demand and an inaccurate sampling of edge regions. In order to compensate for these
deficiencies, another distance measure utilizing an expanded nearest neighbour approach was implemented and compared to the
existing solution. It could be shown that the alternative solution for the determination of the single point uncertainty in repeated
computed tomography (CT) measurements can provide very similar results while having substantially less computational
requirements on the hardware used.
Realistic Image Synthesis of Imperfect Specimens using Generative Networks
Authors:   University of Erlangen-Nürnberg (FAU), Neufeld Deniz ,   University of Erlangen-Nürnberg (FAU), Würfl Tobias ,   Fraunhofer Institute for Integrated Circuits (IIS), Gruber Roland ,   Fraunhofer Institute for Integrated Circuits (IIS), Schön Tobias ,   University of Erlangen-Nürnberg (FAU), Maier Andreas
Published: April 2023

This work explores conditional Generative Adversarial Networks (cGANs) as a tool to create realistic appearing CT slice images
with pre-defined imperfections for the verification of automated defect detection algorithms. We aim to create an effective and
efficient technique to simulate defects in CT slice images by implementing a new method which can simulate realistic textures
and shapes. The problem is stated as an image to image translation task, where a new image is generated based on a given
semantic description of the desired realistic image. This semantic description is a material based segmentation of the image with
additional circular segments indicating the rough size and position of the intended defect. Based upon related work on cGANs,
a convolutional neural network architecture is introduced and applied to our task. This method was trained and evaluated using
2D slice images derived from industrial CT datasets of automotive pistons. Our method showed promising results, producing
convincing images in under one minute of computation with image resolutions of 256 by 256 pixels.
Synthesis and characterization of metal-ceramic composite 316l/sycro
Authors:   Rio de Janeiro State University (UERJ), Alves Haimon ,   International Foundation for Electoral Systems (IFES), Firmino José ,   Federal University of Espírito Santo (UFES), Cavichini Arthur ,   Federal University of Espírito Santo (UFES), Orlando Marcos ,   Federal University of Rio de Janeiro (UFRJ), Tadeu Ricardo
Published: April 2023

The composite formed by 316L steel with 10% of Sr1,8Y0,2CrReO6 (SYCRO) double perovskite was successfully sintered using Top Down nanotechnology associated with powder metallurgy. SEM images showed that the SYCRO nanoparticles were deposited on the steel surface homogeneously. The scattering spectra of the images confirmed the presence of the Sr and Re elements scattered homogeneously on the surface of the composite, which corroborates the images observed by SEM. X-ray microtomography showed a solid build, with few pores and cracks, and a 3D distribution of the main components. X-ray diffraction measurements showed that SYCRO particles were embedded in the 316L steel matrix. Magnetic susceptibility a.c. showed that the composite has ferromagnetism and Tc close to that found in the literature for the ceramic composite Sr1,8Y0,2CrReO6, which certifies that the sintering of the composite was obtained successfully.
2D Contour Reconstruction for Industrial Computed Tomography using Crease Cluster
Authors:   University of Lübeck, Wattenberg Maximilian ,   University of Lübeck, Stille Maik ,   YXLON International GmbH, Klein Philipp ,   University of Lübeck, Buzug Thorsten M.
Published: April 2023

One task of industrial computed tomography in dimensional metrology is to provide surface models of examined objects. Currently,

in the standard approach polygonal surface meshes from reconstructed tomograms are extracted. Precise surface meshes

require a high resolution tomogram, leading to time-consuming reconstruction algorithms. In order to overcome this problem, we

propose a method to approximate the contour by a point cloud of folds, which resemble the most characteristic parts of the object.

These creases are reconstructed from filtered projection images directly in Cartesian space. This cloud of creases will serve as a

basis for the creation of meshes. Initial results of a 2D phantom study indicate that the method reaches reconstruction accuracies

comparable to standard methods while the number of necessary projections is reduced significantly, leading to a notable decrease

in scan time.
Fast detection of cracks in ultrasonically welded parts by inline X-ray inspection
Authors:   University of Antwerpen, Janssens Eline ,   University of Antwerpen, Sijbers Jan ,   University of Ghent (UGent), Dierick Manuel ,   University of Antwerpen, De Beenhouwer Jan
Published: April 2023

Individual inspection of medical devices is crucial to guarantee high quality products but it is also very demanding. Therefore,
in this work, a next generation inline approach is proposed for inspection of ultrasonically welded parts with X-rays in a
production line. The focus of the inspection is in the detection of cracks at the welded interface of these parts. The approach
consists of a two-step procedure in which first, images are reconstructed from a small number of X-ray radiographs and secondly,
crack detection is applied. Results show that implementation of the inline inspection during the production process is feasible in
terms of time and quality constraints.
Automated ROI Localization On Tomographic Projections
Authors:   Moscow State University (MSU), Ivanov Dmitry ,   Russian Academy of Sciences (RAS), Chukalina Marina ,   Russian Academy of Sciences (RAS), Ingacheva Anastasia ,   Russian Academy of Sciences (RAS), Buzmakov Alexey
Published: April 2023

In this study we present an algorithm, used to truncate the empty space outside ROI on a stack of 2D tomographic projections. In this work we will consider the following definition of the region of interest – ROI is the area of the detector which only receives rays incident to the object, during each measurement. We evaluate our method on a phantom data, to get the idea of how the amount of truncated pixels influence reconstruction time and signal-to-noise ratio. We consider SART method as our primary tool of reconstruction. The method is also applied to the real dataset. Significant improvement of the reconstruction time is achieved in both cases.
Analysis of bone microdamage with Twinned Orthogonal Adjustable Tomograph towards fatigue fracture prevention
Authors:   Czech Academy of Sciences (CAS), Presbitero Gerardo ,   Czech Academy of Sciences (CAS), Vopalensky Michal ,   Czech Academy of Sciences (CAS), Kumpova Ivana ,   Czech Academy of Sciences (CAS), Pithartova Katerina
Published: April 2023

We work in the consolidation of previous studies performed by us concerning microdamage developments in bones with use of conventional basic fuchsin staining, in which we stated that age and gamma radiation had a direct influence on the increase in the generation and growth of microfractures, to provoke the fracture of bones by fatigue by means of a novel theoretical model based on a concept called characteristic length. The mentioned conventional staining technique has the disadvantage of being invasive, destructive, two-dimensional (2-D), and tedious. For this reason, the aim of our current work was the use of a world-unique patented computed tomography device – TORATOM. With the use of precipitation barium sulfate process, we identified individual microcracks, which will be analysed in further studies to define better predictive models to understand and prevent fatigue fractures due to stress and fragility related to osteoporosis, which will be useful in developing new clinical approaches to the problem of osteoporosis.
Porosity determination in additively manufactured Ti parts using X-ray tomography
Authors:   Upper Austrian University of Applied Sciences (FH OÖ), Glinz Jonathan ,   Upper Austrian University of Applied Sciences (FH OÖ), Reiter Michael ,   Upper Austrian University of Applied Sciences (FH OÖ), Gastinger Tanja ,   Upper Austrian University of Applied Sciences (FH OÖ), Huskic Aziz ,   Upper Austrian University of Applied Sciences (FH OÖ), Plank Bernhard ,   Upper Austrian University of Applied Sciences (FH OÖ), Kastner Johann ,   Upper Austrian University of Applied Sciences (FH OÖ), Senck Sascha
Published: April 2023

Ti6Al4V is a suitable titanium alloy for all kinds of medical implants and prostheses because of its high durability and biocompatibility. Furthermore, components of high complexity can be produced via additive manufacturing which allows for more flexibility and easy prototyping of patient specific implants. However, this flexibility implies the risk of internal defects resulting from the manufacturing process. The nondestructive investigation of critical components is therefore crucial to avoid premature failure. X-ray micro-computed tomography (XCT) is a method that can resolve internal structures three dimensionally in a non-destructive way. Nevertheless, the probability to detect defects is limited by the achievable resolution and image quality of a scan. In this contribution, we performed a systematic study to determine the pore size distribution in additively manufactured Ti6Al4V parts using XCT. We focused on the influence of scanning parameters such as voxel size, tube voltage and current on the image quality that determines the outcome of the porosity analysis. Image quality was assessed via contrast to noise ratio (CNR) and slanted-edge modulation transfer function (MTF) according to ISO 12233. Furthermore, we optimized the beam hardening correction for the scans and investigated influences of different image denoising algorithms. Results showed that tube voltage and current greatly influence the CNR of the data set while the MTF is, within limits, almost constant as long as the electron beam focus is optimized. With higher physical resolution, smaller defects can be detected, which leads to porosity values of 0.36, 1.35 and 2.54% at 10, 5 and 2.5 μm resolution respectively. Image post-processing can further influence porosity outcome because of the segmentation of noise induced particles. Different image denoising algorithms therefore can heavily reduce porosity values depending on spatial resolution.
Suppression of residual gradients in the flat-field corrected images
Authors:   Czech Academy of Sciences (CAS), Vopalensky Michal ,   Czech Academy of Sciences (CAS), Kumpova Ivana ,   Czech Academy of Sciences (CAS), Vavrik Daniel
Published: April 2023

Flat field correction, based on using the open beam and the dark field images, is a basic method used for correction of the projection images acquired in computed tomography process. The correction suppresses the stationary noise of the detector, caused by non-uniform gain and offset of each pixel, as well as the non-uniformity of intensity caused by the non-flat intensity profile of the incident X-rays beam. In an ideal case, the corrected image should have a constant intensity in the open-beam areas, i.e., everywhere outside the investigated object. However, this is not always true due to several factors, such as drifts of the spot position, wearing out of the target (pitting), etc. In such a case, the background in the flat-field corrected image is not really “flat” or constant. Particularly in radiography, this is an undesired effect, because the intensity values are also influenced in the object area, leading thus to a possible misinterpretation of the image (even for a constant thickness area, the intensity distribution looks like if the thickness was varying). In this paper, a method is described how to compensate this effect in rather an effective way.
Optimisation of surface determination to improve the accuracy and repeatability of detecting unfused powder in AM Aluminum component
Authors:   University of Huddersfield, Tawfik Ahmed ,   University of Huddersfield, Blunt Liam ,   University of Huddersfield, Dawson Christopher ,   University of Huddersfield, Racasan Radu ,   HiETA Technologies Ltd, Bacheva Desi ,   University of Huddersfield, Bills Paul
Published: April 2023

Additive manufacturing (AM) is quickly being recognized as a core technology for producing complex and customized components, so the need for well understood non-destructive testing is more urgent than ever. The mechanical properties of cast components are well studied and non-destructive testing is well established by various methods like XCT and ultrasound. On the other hand, there are big challenges for NDT with regard to additive manufactured components as the pores are different in nature from those found in cast alternatives. In additive manufactured components, the pores could be hollow, filled with partially fused powder or unfused powder. Furthermore, porosity could be due lack of fusion of un-melted powder (low laser energy) or balling up effect (too high laser energy). There is also the possibility of unfused powder within the internal architecture of complex components. In such cases XCT becomes an essential detection tool.
This paper presents the design of an Aluminum (AlSi10Mg) AM artefact / sample with built-in unfused and semi fused powder features. Several defects with different shapes and dimensions were created. Two 1mm cylinder defects were placed inside an 8mm aluminum cylinder artefact. The first defect was located 200μm from the outside envelope of the surface and the second defect was located centrally 1mm from the top surface of the artefact. The built-in defects were used as markers to identify the determined powder grey value. A Nikon XTH 225 (Nikon Metrology, Tring) industrial XCT was used to analyze the pores/ defects’ location and volume. This threshold was utilized to ascertain the optimum ISO value for surface determination. Data processing, surface determination process and defect analysis was carried out using VG Studio Max 3.1 (Volume Graphics, Heidelberg).The artefact was then sectioned to confirm the actual location and dimensions of the designed defects using an Alicona G4 (Alicona, Graz) focus variation instrument.. The results of the scans were determined using two different surface determination strategies. The results obtained from each of the defect analysis were compared to the designed value and the focus variation.
The focus of the study is on providing best practice for selecting inspection parameters, optimizing ISO value for porosity detection and identifying unfused and semi fused powder in AM SLM component.
Generating Meaningful Synthetic Ground Truth for Pore Detection in Cast Aluminum Parts
Authors:   Universität Heidelberg, Fuchs Patrick ,   Volume Graphics GmbH, Kröger Thorben ,   Volume Graphics GmbH, Dierig Tobias ,   Universität Heidelberg, Garbe Christoph S.
Published: April 2023

Labeling a data set is a tedious task, especially when identifying small pores in an artifact-prone three-dimensional computed

tomography (CT) scan of a die cast. Modern deep learning algorithms have the ability to increase the quality and speed of

automated inspection. However, they crave vast amounts of labeled data. Thus, we demonstrate a method to simulate a realistic

CT-data set which allows ground truth labels to be derived automatically. We place procedurally generated pores inside lifelike

material samples, yielding virtual aluminum parts. Using properties of real materials during the simulation, we are able to

create scans comprising the typical CT-artifacts which impede the detection of defects, especially noise, beam hardening, and

ring artifacts. To validate the realism of this data set, we use the simulated data to train different defect detection algorithms,

including convolutional neural networks, and measure their prediction performance on real data showing the aforementioned

artifacts. The corresponding ground truth labeling was derived from scans of higher quality of the same parts.
Study on Energy Weighting Imaging Technology in Multispectral CT
Authors:   Chinese Academy of Science (CAS), Zhiwei Cheng ,   Chinese Academy of Science (CAS), Mohan Li ,   Chinese Academy of Science (CAS), Zhidu Zhang ,   Chinese Academy of Science (CAS), Cunfeng Wie ,   Chinese Academy of Science (CAS), Qiong Xu ,   Chinese Academy of Science (CAS), Baodong Liu ,   Chinese Academy of Science (CAS), Long Wie ,   Chinese Academy of Science (CAS), Zhe Wang
Published: April 2023

The attenuation of X-ray in matter is related to photon energy and material property. The traditional CT imaging technology adopts charge integrating detector, which cannot effectively utilize the photon energy information in imaging. With the ability to distinguish the photon energy, photon counting detector can improve the image quality if appropriate energy weights are chosen according to the attenuation change of matter under different X-ray energies. This paper focuses on the energy weighting imaging method based on the photon counting detector CT. In this paper, various kinds of materials are selected to explore the image-based energy weighting. Imaging experiments show that the energy weighting method can obtain higher contrast-to-noise ratio (CNR) than the conventional photon counting imaging and charge integrating imaging.
Non Destructive Testing of CMC Engine Internal Parts from X-ray Tomographic Images
Authors:   Voxaya SAS, Rodriguez Olivier ,   Voxaya SAS, Porcher Thierry ,   Voxaya SAS, Planes Valentin ,   IRT Saint-Exupery, Mecuson Gautier ,   IRT Saint-Exupery, Bouvier Remi
Published: April 2023

The introduction of Ceramic Matrix Composites (CMCs) for aircraft engines gas turbine components aims at increasing the turbine performance and in-service life on the one hand, and on the other hand saving weight, hence reducing fuel consumption. Material health control of turbine parts is an essential procedure, given the criticality of their operating performance. X-ray tomography is a particularly suitable technique for non destructive testing. However, the images produced by this 3D imaging method can be very large, making computations very time- and memory consuming, especially for characterizing complex porous materials such as CMCs.

Voxaya SAS and IRT Saint-Exupery designed and tested a specific non destructive testing workflow based on Voxaya’s software, Voxilon, for the analysis of CMC engine internal parts from X-ray tomographic images. We present how Voxilon’s innovative architecture and rapid algorithms allows swiftly processing a large number of tomographic images and automatizing the sensitivity analysis of input parameters.
Experimental investigation on the accuracy of XCT measurement of fiber length in fiber reinforced polymers
Authors:   University of Padova (UNIPD), Zanini Filippo ,   University of Padova (UNIPD), Gerardi Giovanni ,   Upper Austrian University of Applied Sciences (FH OÖ), Weissenböck Johannes ,   Upper Austrian University of Applied Sciences (FH OÖ), Heinzl Christoph ,   Upper Austrian University of Applied Sciences (FH OÖ), Kastner Johann ,   University of Padova (UNIPD), Carmignato Simone
Published: April 2023

X-ray computed tomography (XCT) allows performing non-destructive measurements of fibers in fiber-reinforced polymeric materials. The accurate evaluation of fiber orientation and fiber length distribution is particularly useful as these factors have a strong influence on physical and mechanical properties of such materials. XCT data is already successfully used for fiber orientation analysis, whereas the fiber length measurement is more complex as it requires the individual fibers to be identified and segmented. Software tools able to cope with such tasks are available, but the accuracy of XCT fiber length measurement has not been thoroughly investigated so far. In this work, an experimental methodology was developed to determine the accuracy of XCT based fiber length measurements, using a reference object that was specifically designed, produced and calibrated for this purpose.
Convergence Behaviour of Numerical Measurement Uncertainty Evaluation using a Virtual Metrological Computed Tomography System
Authors:   University of Erlangen-Nürnberg (FAU), Wohlgemuth Florian ,   University of Erlangen-Nürnberg (FAU), Hausotte Tino
Published: April 2023

Digital twins of measurement devices offer fascinating applications, e.g. systematic error correction [12] or numerical uncertainty evaluation according to GUM Supplement 1 [5]. The latter is state of the art for tactile coordinate measurements [3]. For Computed Tomography (CT), this is currently not the case [18]. Prior work at the Institute of Manufacturing Metrology showed the potential to numerically evaluate task-specific measurement uncertainties in good agreement with values determined experimentally in accordance with the VDI/VDE standard 2630 Part 2.1 [18] for an unproblematic measurement task (see [8]). Details on the digital twin and the Monte Carlo method used can be found in [19]. In this prior work, the number of simulations for the Monte Carlo trials was chosen based on computational feasibility and expert knowledge. A systematic study of the convergence behaviour is the object of this contribution. Other contributions towards the numerical evaluation of task-specific measurement uncertainties can be found in [9, 15].
Uncertainty of CT dimensional measurements performed on metal additively manufactured lattice structures
Authors:   University of Padova (UNIPD), Zanini Filippo ,   University of Padova (UNIPD), Sorgato Marco ,   University of Padova (UNIPD), Savio Enrico ,   University of Padova (UNIPD), Carmignato Simone
Published: April 2023

Metal parts with controlled lattice structures can effectively be produced via additive manufacturing (AM) technologies. However, one of the critical aspects of metal AM products is the dimensional and geometrical accuracy. X-ray computed tomography (CT) can be applied to enable advanced control methods that are fundamental for improving the geometrical characteristics and the quality of complex metal AM parts. In this work, Ti6Al4V lattice structures produced by laser powder bed fusion were analysed using a metrological X-ray CT system. Two different approaches for determining the uncertainty of dimensional measurements based on the CT reconstructed volumes were implemented and compared: the "substitution method" and the "multiple measurements" approach. Advantages and limitations of both approaches are identified and discussed.
Influence of different mounting strategies on the random measurement error in industrial computed tomography
Authors:   Karlsruhe Institute of Technology (KIT), Schild Leonard ,   Karlsruhe Institute of Technology (KIT), Jung Max ,   Karlsruhe Institute of Technology (KIT), Häfner Benjamin ,   Karlsruhe Institute of Technology (KIT), Lanza Gisela
Published: April 2023

In order to perform measurements in industrial computed tomography (CT), the specimen in question has to be mounted on the kinematic system of the CT device. In principle this applies to all measuring machines, however, it is an especially critical step of a CT measurement as there are no companies providing mounting systems in particular for CT applications that have been tried and tested by many years of usage. As a mounting system for CT applications should not interfere with x-ray beams to ensure an uncorrupted measurement, many users rely on special mountings cut from foam, 3D printed mounts or custom- made parts. However, there has not been a systematic survey on which mounting strategy leads to minimal random error in measurement results. Therefore, this paper aims at determining the influence of different mounting strategies on the random measurement error and image quality of the resulting scans. To this end, measurements of a defined test-object using different mountings are performed and compared with respect to these quality parameters. Finally, a recommendation for the optimal choice of a mounting system based on the results is given.
Traceable measurement of the instrument transfer function in dXCT
Authors:   Physikalisch-Technische Bundesanstalt (PTB), Illemann Jens
Published: April 2023

In dimensional X-ray CT (dXCT), the definition of a resolution describing parameter (metrological structural resolution) is not standardized conclusively yet. The instrument transfer function (ITF) is currently being discussed in national and international standardization bodies as one candidate for such a parameter. The ITF describes the wavelength-dependent transfer of a surface modulation - which is the main focus of dXCT - in contrast to the modulation transfer function (MTF), a well-known parameter which describes the grey-value amplitude transfer function after volume reconstruction without including a surface determination. In this article, a practical implementation of two differently sized new ITF reference standards is presented. Their idea is to use a height profile - with nearly constant spectral amplitude and bandwidth-limited - which is extended periodically. This profile is diamond-turned on the outer side of a tube and can be segmented to obtain identical pieces. One piece is calibrated pars pro toto with a high-resolution tactile scanner (HRTS) to obtain the reference ITF. Comparisons, CT parameter dependency tests and simulations highlight the benefit of this new type of standards for the determination of the ITF as a measure for resolution.
Surface Point Determination in Subvoxel Accuracy from Pre-Segmented Multi-Material Volume Data for Metrological Applications
Authors:   Dresden University of Technology (TU Dresden), Stopp Lukas Joachim ,   Dresden University of Technology (TU Dresden), Christoph Raoul ,   Dresden University of Technology (TU Dresden), Weise Hartmut
Published: April 2023

When using X-ray computed tomography in coordinate metrology, methods for the determination of surface points at subvoxel accuracy (hereinafter subvoxeling) are essential. In recent years, the demand to measure objects consisting of several materials has increased. While subvoxeling edge detection operators proven for mono-material applications are rarely suitable for multi-material specimens, a number of algorithms enable segmentation at voxel resolution. To overcome the gap, a new method has been developed. In a first step, volumes of material probabilities are calculated using a (pre-)segmentation while obtaining the implicitly given subvoxel-accurate information. The surface points can then be calculated using common edge detection operators. Initial results of the validation based on selected examples are presented.
Single-shot, high sensitivity X-ray phase contrast imaging system based on a Hartmann mask
Authors:   Imagine Optic, De La Rochefoucauld Ombeline ,   Sapienza University of Rome, Begani Provinciali Ginevra ,   Sapienza University of Rome, Cedola Alessia ,   Brookhaven National Laboratory, Idir Mourad ,   Imagine Optic, Dovillaire Guillaume ,   Imagine Optic, Harms Fabrice ,   Imagine Optic, Legrand Jérôme ,   Imagine Optic, Levecq Xavier ,   Institut Bergonié, Mastropietro Francesca ,   Imagine Optic, Nicolas Lionel ,   Imagine Optic, Oudjedi Laura ,   Imagine Optic, Piponnier Martin ,   ENSTA ParisTech, Zeitoun Philippe
Published: April 2023

Significant efforts are currently ongoing in X-Ray imaging to provide multimodal imaging systems, targeting better sensitivity and specificity for both biomedical or non-destructive testing (NDT) applications. X-Ray Phase Contrast Imaging (X-PCI) shows great capability to differentiate elements with similar absorption. For example, in the medical field, knowing the chemical composition of breast microcalcifications would help to differentiate malign and benign tumors. The composition can be determined from the measurement of the phase as the optical index of materials is directly related to the composition. We propose a novel, high-sensitivity X-ray quantitative phase imaging system based on a Hartmann wavefront sensor. The system provides high resolution (20?m without magnification) and high sensitivity (~100 nrad), and is compatible with tomographic experiments using both synchrotron beamlines or laboratory sources. We present here our first X-PCI prototype as well as the first images obtained. We also present an alternative design based on the same approach, providing larger field-of-view at the cost of some trade-off regarding resolution and sensitivity and the first tomographic results obtained with this imaging system.
Industrial applications of computed microtomography (microCT) technique
Authors:   Federal University of Rio de Janeiro (UFRJ), Machado Alessandra Silveira ,   Federal University of Rio de Janeiro (UFRJ), Silva Aline Saddock ,   Federal University of Rio de Janeiro (UFRJ), De Araujo Olga Oliveira ,   Federal University of Rio de Janeiro (UFRJ), De Oliveira Davi Ferreira ,   Federal University of Rio de Janeiro (UFRJ), Lopes Ricardo Tadeu
Published: April 2023

Microcomputed tomography is a non-invasive and non-destructive essential tool for morphological and topological studies of internal structures of different materials allowing 3D visualizations. Currently, many studies focusing industrial applications using microCT as a tool are being developed. In all applications, microCT proved to be an adequate technique for the characterization of different materials allowing accurate and reliable qualitative and quantitative assessments.
Computed tomography with fast-neutron sources
Authors:   Lawrence Livermore National Laboratory, Johnson Micah S. ,   Lawrence Livermore National Laboratory, Anderson Scott G. ,   Lawrence Livermore National Laboratory, Bleuel Darren ,   Lawrence Livermore National Laboratory, Caggiano Joseph A. ,   Lawrence Livermore National Laboratory, Fitsos Peter J. ,   Lawrence Livermore National Laboratory, Gibson David ,   Lawrence Livermore National Laboratory, Hall James M. ,   Lawrence Livermore National Laboratory, Marsh Roark ,   Lawrence Livermore National Laboratory, Ratkiewicz Andrew ,   Lawrence Livermore National Laboratory, Rusnak Brian
Published: April 2023

Lawrence Livermore National Laboratory (LLNL) is near-completion of a quasi-monoenergetic neutron source for fastneutron imaging and computed tomography (CT). The source is expected to produce 10-MeV neutrons with an on-axis flux of ~1011 per second per steradian through a collimated aperture with a ~7-degree opening angle. The application for this source is imaging and CT of low-Z materials heavily shielded by high-Z materials. Fast-neutron imaging and CT is a non-destructive technique for very thick objects. We have radiographed a variety of objects using various sources of fast neutrons. We will discuss our CT reconstruction methods and results from these measurements. We will also discuss our results as they relate to our expectations of the near-complete neutron source at LLNL.
Scattering Correction of CBCT Projections for the Quality Enhanced CT Reconstruction Using an Efficient Monte Carlo Photon Transport Model
Authors:   University of Stuttgart, Alsaffar Ammar ,   University of Stuttgart, Mammadov Gasim Mammadov ,   University of Stuttgart, Simon Sven
Published: April 2023

In industrial computed tomography, cone beam computed tomography (CBCT) setups are state-of-art because of its capabilities and speed. However, this technique highly suffers from the effect of scatter in comparison to fan beam computed tomography due to the large scanning 2D field of view. CBCT is more preferable to be used since it is considerably faster. In this work a fast Monte Carlo forward projection model based on photon transport has been developed to subtract the scatter from the measured X-ray projections. The ability of this forward model to compute any complex object from CAD models based on meshes polyhedron validate the proposed scatter subtraction algorithm. Depending on the number of photons used, the complexity and the size of the object each X-ray projection is obtained within two minute or less with this model. In addition to the use of the variance reduction techniques for a fast calculation of the scatter, the proposed scatter subtraction algorithm has been further reduced in computation time by the use of smoothing filters, mainly by the use of Savitzky-Golay filter which is a type of a squares polynomial approximation filter, this kind of smoothing plays significant role in the reduction of the computations time.