Assessment Of Defects Research Articles

MATHEMATICAL MODELING OF TECHNICAL CONDITION OF MECHANISMS

The research is aimed at revealing the problems of modeling technical diagnostics of mechanisms and machines. To assess the technical condition of machines and the formation of diagnostic features, a method based on the application of the mathematical theory of pattern recognition is proposed. It is shown that technical diagnostics of machines and mechanisms can be interpreted as the recognition of classes of technical condition of the object by the set of its technical characteristics. At the same time, it is established to what class the current recognized state belongs. The conducted studies are covered against the background of the assessment of gear defects. Such studies have shown that in the early stages of defect development there is a process when synchronous components do not grow, and all the extra power from the defect is concentrated in asynchronous harmonics.

Reliability and validity test of a novel three-dimensional acetabular bone defect classification system aided with additive manufacturing

BackgroundAccurate assessment of acetabular defects and designing precise and feasible surgical plans are essential for positive outcomes of hip revision arthroplasty. Additive manufacturing (AM) is a novel technique to print physical object models. We propose a three-dimensional acetabular bone defect classification system aided with AM model, and further assess its reliability and validity under blinded conditions.MethodsWe reviewed 104 consecutive patients who underwent hip revision arthroplasty at our department between January 2014 and December 2019, of whom 45 had AM models and were included in the reliability and validity tests. Three orthopedic surgeons retrospectively evaluated the bone defects of these 45 patients with our proposed classification, made surgical plans, and repeated the process after 2 weeks. The reliability and validity of the classification results and corresponding surgical plans were assessed using the intra-class correlation coefficient or kappa correlation coefficient.ResultsThe reliability and validity of the classification results were excellent. The mean initial intra-class correlation coefficient for inter-observer reliability was 0.947, which increased to 0.972 when tested a second time. The intra-observer reliability ranged from 0.958 to 0.980. Validity of the classification results also showed a high kappa correlation coefficient of 0.951–0.967. When considering corresponding surgical plans, the reliability and validity were also excellent, with intra-class correlation coefficients and kappa correlation coefficients measuring all over 0.9.ConclusionsThis three-dimensional acetabular defect classification has excellent reliability and validity. Using this classification system and AM models, accurate assessment of bone defect and reliable surgical plans could be achieved. This classification aided with AM is a promising tool for surgeons for preoperative evaluation.

Classification of Coffee Bean Defects Using Gray-Level Co-Occurrence Matrix and K-Nearest Neighbor

Defects in coffee beans can significantly affect the quality of coffee production so that defects in coffee beans can cause a decreasing the level of coffee production. The purpose of this study is to implement the GLCM (gray-level co-occurrence matrix) and the K-NN (k-nearest neighbor) method on a web-based program and provided a website to detect coffee bean defects. This study uses the GLCM algorithm to extract the features of the coffee images and uses the K-NN algorithm to classify the defect level of coffee beans. The system development was built using Unified Modeling Language. The development of this website was utilized the programming structure of PHP, HTML, CSS, Javascript, Mozilla Firefox as a browser for the website and MySql for the database management systems. The results show that the system can provide the output in the form of a classification level of the defect level of the coffee bean images. Then, the accuracy of the coffee bean defect assessment was achieved by 90%. Finally, this study concluded that the proposed system could help the coffee farmers determine the defect level of the coffee beans using images input.

Automated quantitative high-throughput multiplex immunofluorescence pipeline to evaluate OXPHOS defects in formalin-fixed human prostate tissue

Advances in multiplex immunofluorescence (mIF) and digital image analysis has enabled simultaneous assessment of protein defects in electron transport chain components. However, current manual methodology is time consuming and labour intensive. Therefore, we developed an automated high-throughput mIF workflow for quantitative single-cell level assessment of formalin fixed paraffin embedded tissue (FFPE), leveraging tyramide signal amplification on a Ventana Ultra platform coupled with automated multispectral imaging on a Vectra 3 platform. Utilising this protocol, we assessed the mitochondrial oxidative phosphorylation (OXPHOS) protein alterations in a cohort of benign and malignant prostate samples. Mitochondrial OXPHOS plays a critical role in cell metabolism, and OXPHOS perturbation is implicated in carcinogenesis. Marked inter-patient, intra-patient and spatial cellular heterogeneity in OXPHOS protein abundance was observed. We noted frequent Complex IV loss in benign prostate tissue and Complex I loss in age matched prostate cancer tissues. Malignant regions within prostate cancer samples more frequently contained cells with low Complex I & IV and high mitochondrial mass in comparison to benign–adjacent regions. This methodology can now be applied more widely to study the frequency and distribution of OXPHOS alterations in formalin-fixed tissues, and their impact on long-term clinical outcomes.

Real-Time Instance Segmentation of Metal Screw Defects Based on Deep Learning Approach

Abstract In general, manual methods are often used to inspect defects in the production of metal screws. As deep learning shines in the field of visual detection, this study employs the You Only Look At CoefficienTs (YOLACT) algorithm to detect the surface defects of the metal screw heads. The raw images with different defects are collected by an automated microscopic camera scanning system to build the training and validation datasets. The experimental results demonstrate that the trained YOLACT is sufficient to achieve a mean average accuracy of 92.8 % with low missing and false rates. The processing speed of the trained YOLACT reaches 30 frames per second. Compared with other segmentation methods, the proposed model provides excellent performance in both segmentation and detection accuracy. Our efficient deep learning-based system may support the advancement of non-contact defect assessment methods for quality control of the screw manufacture.

‘Islamization of Knowledge’: a Utopian dream or a viable project? A critique of the views of two prominent Iranian proponents of the ‘Islamization Project’

ABSTRACT The main argument of the present paper is that although the intention of at least some of those individuals who are trying to produce ‘Islamized Knowledge’ may be admirable, the methods and approaches they have adopted is not conducive to the aim they have in mind. The paper consists of the following parts: a short introduction (Sec. 0); a brief history of the ‘Islamization of Knowledge’ (Sec. I); A brief account of the main tenets of the theoretical framework which informs the present study, namely, Critical Rationalism (Sec. II); a short assessment of the general defects of all projects of Islamization of knowledge (Sec. III); a critical evaluation of the views of two contemporary Iranian advocates of the ‘Islamization of Knowledge’ (Secs. IV & V); and the conclusion (Sec. VI).

Short Range Pipe Guided Wave Testing Using SH0 Plane Wave Imaging for Improved Quantification Accuracy.

Detection and criticality assessment of defects appearing in inaccessible locations in pipelines pose a great challenge for many industries. Inspection methods which allow for remote defect detection and accurate characterisation are needed. Guided wave testing (GWT) is capable of screening large lengths of pipes from a single device position, however it provides very limited individual feature characterisation. This paper adapts Plane Wave Imaging (PWI) to pipe GWT to improve defect characterization for inspection in nearby locations such as a few metres from the transducers. PWI performance is evaluated using finite element (FE) and experimental studies, and it is compared to other popular synthetic focusing imaging techniques. The study is concerned with part-circumferential part-depth planar cracks. It is shown that PWI achieves superior resolution compared to the common source method (CSM) and comparable resolution to the total focusing method (TFM). The techniques involving plane wave acquisition (PWI and CSM) are found to substantially outperform methods based on full matrix capture (FMC) in terms of signal-to-noise ratio (SNR). Therefore, it is concluded that PWI which achieves good resolution and high SNR is a more attractive choice for pipe GWT, compared to other considered techniques. Subsequently, a novel PWI transduction setup is proposed, and it is shown to suppresses the transmission of unwanted S0 mode, which further improves SNR of PWI.

Assessment of visual field defects and optic disc changes in patients with high myopia

Glaucoma is a leading cause of global irreversible blindness. Primary open angle glaucoma (POAG) is the most common form of glaucoma and affects 44.1 million individuals worldwide. Furthermore, there is a disproportionate burden of POAG in Asia, with Asians accounting for 53% (23.5 million) of POAG cases worldwide. While early detection of POAG is important in delaying or halting the progression of the disease, a better understanding of the interplay between major risk factors for POAG is crucial. aim of this study is to assess the effects of myopia on POAG in the patient attending MYH Indore OPD (central India). It is a hospital based, prospective, non-randomised case study. 60 eyes of high myopic patients and 60 eyes of general Ophthal OPD patients were evaluated. The statistical software namely SPSS 19.0, were used for the analysis of the data and Microsoft word and Excel have been used to generate graphs, tables etc. In our study, we found that, in high myopic patient, there were increase in chances of glaucomatous optic disc changes, and these changes were influenced by age and not influenced with gender, degree of myopia.

Some aspects of modeling of technical diagnostics of mechanisms

The research is aimed at revealing the problems of modeling technical diagnostics of mechanisms and machines. To assess the technical condition of machines and the formation of diagnostic features, a method based on the application of the mathematical theory of pattern recognition is proposed. It is shown that technical diagnostics of machines and mechanisms can be interpreted as the recognition of classes of technical condition of the object by the set of its technical characteristics. At the same time, it is established to what class the current recognized state belongs. The conducted studies are covered against the background of the assessment of gear defects. Such studies have shown that in the early stages of defect development there is a process when synchronous components do not grow, and all the extra power from the defect is concentrated in asynchronous harmonics.

Localization and assessment of breakage defect in cables based on time–frequency domain reflectometry

Cables are very important in urban power system due to the small occupied area and excellent electrical properties. However, the breakage defect caused by manufacturing errors and improper installation can lead to great loss to the power system. Thus, the localization and assessment of breakage defect is necessary. In this paper, a non-destructive method based on time–frequency​ domain reflectometry is utilized, and the position and degree of breakage defect can be obtained by the peaks of the localization curve. Besides, pseudo Wigner–Ville distribution is proposed to avoid the cross-term interference problem in time–frequency domain reflectometry. In experiments, breakage defects of different degrees were caused to the same position of the target cable. The defects are localized accurately with errors less than 1% of the entire cable length, and as the degree of damage increases, the peak value of the assessment curve at the defect becomes larger accordingly.

Feasibility of an accelerated 2D-multi-contrast knee MRI protocol using deep-learning image reconstruction: a prospective intraindividual comparison with a standard MRI protocol

ObjectivesThe aim of this study was to evaluate the image quality and diagnostic performance of a deep-learning (DL)–accelerated two–dimensional (2D) turbo spin echo (TSE) MRI of the knee at 1.5 and 3 T in clinical routine in comparison to standard MRI.Material and methodsSixty participants, who underwent knee MRI at 1.5 and 3 T between October/2020 and March/2021 with a protocol using standard 2D–TSE (TSES) and DL–accelerated 2D–TSE sequences (TSEDL), were enrolled in this prospective institutional review board–approved study. Three radiologists assessed the sequences regarding structural abnormalities and evaluated the images concerning overall image quality, artifacts, noise, sharpness, subjective signal-to-noise ratio, and diagnostic confidence using a Likert scale (1–5, 5 = best).ResultsOverall image quality for TSEDL was rated to be excellent (median 5, IQR 4–5), significantly higher compared to TSES (median 5, IQR 4 – 5, p < 0.05), showing significantly lower extents of noise and improved sharpness (p < 0.001). Inter- and intra-reader agreement was almost perfect (κ = 0.92–1.00) for the detection of internal derangement and substantial to almost perfect (κ = 0.58–0.98) for the assessment of cartilage defects. No difference was found concerning the detection of bone marrow edema and fractures. The diagnostic confidence of TSEDL was rated to be comparable to that of TSES (median 5, IQR 5–5, p > 0.05). Time of acquisition could be reduced to 6:11 min using TSEDL compared to 11:56 min for a protocol using TSES.ConclusionTSEDL of the knee is clinically feasible, showing excellent image quality and equivalent diagnostic performance compared to TSES, reducing the acquisition time about 50%.Key Points• Deep-learning reconstructed TSE imaging is able to almost halve the acquisition time of a three-plane knee MRI with proton density and T1-weighted images, from 11:56 min to 6:11 min at 3 T.• Deep-learning reconstructed TSE imaging of the knee provided significant improvement of noise levels (p < 0.001), providing higher image quality (p < 0.05) compared to conventional TSE imaging.• Deep-learning reconstructed TSE imaging of the knee had similar diagnostic performance for internal derangement of the knee compared to standard TSE.

Machine learning with knowledge constraints for process optimization of open-air perovskite solar cell manufacturing

Machine learning with knowledge constraints for process optimization of open-air perovskite solar cell manufacturing

Optimal Follow-Up Duration for Assessment of Birth Defects After In Vitro Fertilization-Embryo Transfer: A Multicenter 5-Year Cohort Study in China.

ObjectiveTo investigate the impact of a 5-year follow-up on the incidence of identified birth defects in children conceived using assisted reproductive technologies (ART).MethodsA 5-year cohort study was performed in three ART centers from January 2013 to October 2018. 1,543 women with 1,985 infants who delivered successfully or underwent termination of pregnancy due to malformations were recruited in this study. Follow-up was conducted by phone interview, 7 days, 1 year, 3 years, and 5 years after birth. Collected data included whether one or more birth defects were diagnosed, the category of birth defects, and when the malformation was diagnosed. Cumulative incidence of birth defects and the loss to follow-up rate of each follow-up was compared.ResultsAccording to the diagnostic criterion of birth defects, 111 cases of one or more birth defects were recorded, with a total of 117 birth defects after the 5-year follow-up. 0.2% (4/1,985) of birth defects were diagnosed before delivery; 2.7% (54/1,985) at 7 days; 5.0% (100/1,985) after 1 year; 5.5% (109/1,985) after 3 years; and 5.6% (111/1,985) after 5 years. 3.4% (4/117) of defects were diagnosed prenatally, 45.3% (53/117) of defects diagnosed within the first 7 days after delivery, 40.2% (47/117) diagnosed during 7 days to 1 year, and 9.4% (11/117) of defects diagnosed in 1–3 years after birth. The remaining 1.7% (2/117) of defects were diagnosed between the ages of 3 and 5 years. Among the 1,543 patients, 99.9% patients (1,542/1,543) responded to the telephone interview at 7 days after delivery; the response rate was 89.0% (1,373/1,543) at 1 year, 81% (1,250/1,543) at 3 years, and 64.5% (995/1,543) after 5 years.ConclusionWe suggest that in ART, 1-year follow-up should be the minimum requirement and 3-year follow up the optimal length of follow-up that balances resource requirements with ascertainment completeness.

ЄВРОПЕЙСЬКА ПРАКТИКА ВИРІШЕННЯ ПРОБЛЕМ ЕФЕКТИВНОГО ФУНКЦІОНУВАННЯ ПОВЕРХНЕВОЇ ОБРОБКИ ПОКРИТТЯ. ВІДПОВІДНІСТЬ ХАРАКТЕРИСТИК ПОВЕРХНЕВОЇ ОБРОБКИ ТЕХНІЧНИМ УМОВАМ ДСТУ EN 12271:2021 (EN 12271:2006, IDT)

Introduction. The wearing course of a road pavement is in complicated operational conditions in combination with adverse weather and climatic factors that are characteristic of the country for most of the year. These factors make high demands on the wearing course, in particular arranged by the method of a surface dressing. European practice of solving these issues is based on the provisions of a set of standards that can serve to solve the problems of effective functioning of a surface dressing on roads in Ukraine. Problem statement. The introduction of the requirements of the Association Agreement between Ukraine and the EU [1] into the road sector on a new favorable regime for economic relations, improvement of trade and investment are key factors in economic modernization and sustainable development of the country. European realities indicate that one of the prerequisites for the effective functioning of the road network is, first of all, implementation of modern standards. Actually, in our country there is an urgent need for their updating, in particular for the modern practice of solving the issues for the arrangement of surface dressing of the pavement, especially its design and quality control of work. Therefore, for implementation of the requirements of this Agreement, “DerzhdorNDI” SE has prepared a comprehensive set of national standards in this area with an identical degree of compliance with European requirements. Purpose. The purpose of the work is to promote the implementation of national standards with an identical degree of compliance with European requirements for the efficient operation of layers, arranged by the method of surface dressing on the roads in Ukraine. In this regard, at the present stage, only those requirements are considered, which are set out in the DSTU EN 12271: 2021 (EN 12271: 2006, IDT) «Surface dressing. Specifications» which is being prepared for publication by the National Standardization Body of Ukraine. The related standards, which are applied as a whole, will be updated and presented after their entry into force in the following parts of the article for the acquaintance of the road community. These standards are: –– DSTU EN 12272-1:2021 (EN 12272-1:2002, IDT) Surface dressing - Test methods - Part 1: Rate of spread and accuracy of spread of binder and chippings [2]; –– DSTU EN 12272-2:2020 (EN 12272-2:2003, IDT) Surface dressing - Test methods - Part 2: Visual assessment of defects [3]; –– DSTU EN 12272-3:2020 (EN 12272-3:2003, IDT) Surface dressing. – Test method - Part 3: Determination of binder aggregate bonding by Vialit plate shock test method [4]. Materials and methods Analysis of the national standard DSTU EN 12271: 2021_ (EN 12271: 2006, IDT) Surface dressing - Requirements with identical degree of conformity EN 12271: 2006 (version en) Surface dressing - Requirements[5]. Results The requirements of the national standard for the effective functioning of the surface dressing of roads in Ukraine are considered, further use of which provides an opportunity to improve the performance of works for its arrangement. Conclusion.The implementation of the requirements of the standard will contribute to the establishment of scientifically sound standards for surface dressing. The priority approaches proposed in it regarding requirements, design process and quality control can be approved as modern, requiring application in the road industry. In particular, it is appropriate to introduce requirements for the mandatory arrangement of the test site to confirm surface dressing performance (Type Approval Installation Trial (TAIT)), or measures taking into account the specifics of Factory Production Control (FPC). The use of the requirements of the standard will be facilitated by the development of country regulations or practical recommendations based on regional local conditions, and their implementation in order to create the most relevant areas of effective forms of improving the quality of surface dressing.

Ion beam-based coincidence Doppler broadening spectroscopy of positron annihilation radiation: The experiences of Tehran Van de Graaff lab

Coincidence Doppler Broadening Spectroscopy of positron annihilation radiation is developed using high energy gamma-rays instead of standard positron source for defect assessment in thick samples. A 2.5 MeV proton beam of a Van de Graaff accelerator is used to generate high-energy gamma-ray through 19Fp,αγ16O nuclear reaction. The collimated gamma-ray is used to generate positron inside the sample. The performance of the technique to support the positron annihilation spectroscopy experiment is evaluated by investigation of the defect evolution of five low-carbon steel samples preloaded during the uniaxial tension test. The variation of the S-parameter versus strain is investigated and discussed considering the engineering stress-strain curve of the samples. Moreover, the advantages and limitations of the technique over the conventional CDBS are discussed. The developed spectrometer provides a systematic approach for the defect assessment in thick high-Z elements samples.

Risks Associated with the Use of Hydrogen as an Energy Carrier or Source

Hydrogen is a dangerous gas due to its low ignition energy, wide flammability range, promotion of the embrittlement of steel, and its high coefficient of permeation for polymers. The fracture toughness and failure elongation of pipe steels are strongly impacted by hydrogen embrittlement, whereas yield stress and ultimate strength are moderately impacted. Specific tools are required for the pipe defect assessment used for the transport of hydrogen, which is pure or blended with natural gas. The safety factors associated with cracks or scratches are obtained through the failure assessment diagram or the notch failure assessment diagram. The corrosion defects are assessed by limit analysis, and the estimated repair factor and dents are evaluated by computing the damage value under service pressure. The design factor in the calculation of the maximum admissible operating pressure (MAOP) is modified depending on the location of the pipes to account for the lethal risks from the torch effect or explosion. It is crucial to monitor the leaks due to hydrogen permeation through domestic hydrogen distribution networks, particularly in closed areas.

Identification and Categorization of Building Defects

The problem of building defects is one of the common problems that occur throughout the lifecycle of the building. The construction stakeholders consider it a critical issue that led to costs and time implications of reworks. Mostly, repairing construction defects requires a cost approximately ranging from 2.4% to 3.15% of the total cost of building. Therefore, the current study looks forward to discovering and classifying the common factors contributing to construction defects. To achieve this objective, the researcher adopted a qualitative method to collect and analyze the needed data through deep review of several previous studies that focused on the causes of building defects. Accordingly, this study identified 57 common contributing factors of building defects, which are classified into five groups according to their sources. These groups are Factors related to design, Factors related to construction, Factors related to materials, Factors related to human and External factors. Understanding the contributing factors of the building defects can help construction stakeholders take and develop various strategies to reduce the existence of defects in newly constructed buildings. Positively, the findings of this study could upgrade the management efficiency of the building defects assessment process in the future, which will help to avoid them as much as possible.

The study of the specific defects occurrence at electron-beam welding (EBW) of titanium alloys

The article presents an analytical assessment of specific defects in electron-beam welding of titanium alloys; the defects distribution locations in areas of the welding joint are established. It was found by analysis that the formation of specific defects (dark streaks, pore chains) and their locations are influenced by EBL modes (welding speed, amperage) and technological operations of preparing edges for welding (presence of capillary-condensed moisture). Other defects (faulty fusion and incomplete fusion) are affected by the EBL modes, the error in the adjustment of the electron beam, the insufficient heat input and the penetrating power of the beam.

Advanced quantitative 3D imaging improves the reliability of the classification of acetabular defects.

Classifying complex acetabular defects in revision total hip arthroplasty (THA) by means of conventional radiographs comes with significant limitations. Statistical shape modelling allows the virtual reconstruction of the native pelvic morphology, hereby enabling an analytic acetabular defect assessment. Our objective was to evaluate the effect of advanced imaging augmented with analytic representations of the defect on (1) intra- and inter-rater reliability, and (2) up- or downscaling of classification scores when evaluating acetabular defects in patients undergoing revision THA. The acetabular defects of 50 patients undergoing revision THA were evaluated by three independent, fellowship-trained orthopaedic surgeons. Defects were classified according to the acetabular defect classification (ADC) using four different imaging-based representations, namely, standard radiographs, CT imaging, a virtual three-dimensional (3D) model and a quantitative analytic representation of the defect based on a statistical shape model reconstruction. Intra- and inter-rater reliabilities were quantified using Fleiss' and Cohen's kappa scores, respectively. Up- and downscaling of classification scores were compared for each of the imaging-based representations and differences were tested. Overall inter-rater agreement across all imaging-based representations for the classification was fair (κ 0.29 95% CI 0.28-0.30). Inter-rater agreement was lowest for radiographs (κ 0.21 95% CI 0.19-0.22) and increased for other representations with agreement being highest when using analytic defect models (κ 0.46 95% CI 0.43-0.48). Overall intra-rater agreement was moderate (κ 0.51 95% CI 0.42-0.60). Intra-rater agreement was lowest for radiographs (κ 0.40 95% CI 0.23-0.57), and highest for ratings including analytic defect models (κ 0.64:95% CI 0.46-0.82). Virtual 3D models with quantitative analytic defect representations upscaled acetabular defect scores in comparison to standard radiographs. Using 3D CT imaging with statistical shape models doubles the intra- and inter-rater reliability and results in upscaling of acetabular defect classification when compared to standard radiographs. This method of evaluating defects will aid in planning surgical reconstruction and stimulate the development of new classification systems based on advanced imaging techniques.

A new class of alumina-forming superalloy for 3D printing

A new class of crack-resistant nickel-based superalloy containing high γ′ fraction is studied for the laser-powder bed fusion (L-PBF) process. The effects of the (Nb+Ta)/Al ratio is emphasized, a strategy that is shown to confer excellent low-temperature strength whilst maintaining oxidation resistance at high temperatures via stable alumina scale formation. The processability of the new alloys is characterized with respect to defect assessment by micro-focus X-ray computed tomography; use is made of a prototype turbine blade geometry and the heritage alloy CM247LC as a benchmark. In all cases, some processing-related porosity is present in thin wall sections such as the trailing edge, but this can be avoided by judicious processing. The cracking seen in CM247LC – in solid-state, liquation and solidification forms – is avoided. A novel sub-solvus heat treatment strategy is proposed which takes advantage of AM not requiring solutioning; super-solvus heat treatment is inappropriate since it embrittles the material by deterioration of the texture and coarsening of grain boundary carbides. The tensile strength of the new superalloy is greatest when the Nb+Ta content is highest and exceeds that of CM247LC up to ∼900°C. The oxidation resistance is best when Al content is highest, and oxidation-assisted cracking resistance maximized when the (Nb+Ta)/Al ratio is balanced. In all cases these are equivalent or superior to that of CM247LC. Nevertheless, the creep resistance of the new alloys is somewhat inferior to that of CM247LC for which the γ′, C, and B contents are higher; this implies a processing/property trade-off which requires further clarification.