Portion Of Defects Research Articles

Finite element investigation for improving chest wall reconstruction process using ceramic and polymeric implants

Car accidents, infections caused by bacteria or viruses, metastatic lesions, tumors, and malignancies are the most frequent causes of chest wall damage, leading to the removal of the affected area. After excision, artificial bone or synthetic materials are used in chest wall reconstruction to restore the skeletal structure of the chest. Chest implants have traditionally been made from metallic materials like titanium alloys due to their biocompatibility and durability. However, the drawbacks of these materials have prompted researchers to seek alternative materials for use in the reconstruction process. This research aims to explore alternatives to metallic implants in order to overcome their drawbacks and enhance the performance of chest wall reconstruction using the finite element method. In this research, customized implants for the ribs and cartilages are used to repair the defective portion of the chest wall. The implants are made from various materials, including stiff bioceramics (alumina and zirconia), soft polymers (polyether ether ketone (PEEK) and polyethylene (PE)), and polymeric composites (carbon fiber-reinforced PEEK 30 and 60% (CFP 30 and 60%)) as alternatives for titanium. They are tested under normal breathing and impact loading conditions. The null hypothesis suggests that stiff implants will provide optimal results. The results illustrate that when using alumina implants, under normal breathing, the maximum tensile and compressive stresses increased to 11.41 and 15.86 MPa on ribs, while decreasing to 0.32 and 0.324 MPa, and 0.96 and 0.56 Pa on cartilages and lung respectively, compared to titanium. Conversely, when using PE implants, the maximum tensile and compressive stresses decreased to 5.69 and 8.2 MPa on ribs and increased to 0.4 and 0.42 MPa, and 1.71 and 1.1 MPa on cartilages and lung respectively. Under impact force, compared to titanium, the maximum tensile and compressive stresses increased to 47.5 and 49.8 MPa on ribs, and decreased to 1.91 and 6.15 MPa, and 4.56 and 7.7 Pa on cartilages and lung respectively, when using alumina implants. On the other hand, the maximum tensile and compressive stresses decreased to 31 and 23 MPa on ribs and increased to 2.52 and 7.83 MPa, and 5.8 and 9.3 MPa on cartilages and lung respectively, when using PE implants. The highest tensile and compressive strains on ribs were 6,162 and 6,235 µε when using alumina implants under impact force. Additionally, the highest tensile and compressive strains on cartilages and lung were 11,192 and 20,918 µε and 5,836 and 9,335 µε, respectively, when using PE implants. For screws, the peak values of von Mises stress were 61.6 MPa and 433.4 MPa under normal breathing and impact force respectively, when using PE implants. In fatigue analysis, alumina, PEEK, and PE implants failed under impact force as the maximum equivalent alternating stresses exceeded their fatigue limits, resulting in safety factors of less than one. It was concluded that stiff bioceramic implants (alumina and zirconia) produced the lowest stresses and strains on the surrounding cartilages and underlying lung, and the highest stresses and strains on the surrounding ribs, unlike soft PEEK and PE implants. Additionally, CFP 30% and 60% implants distributed stresses on the ribs, cartilages, and lungs similarly to titanium implants. Furthermore, the tensile and compressive stresses and strains on the ribs, cartilages, and lungs did not exceed allowable limits for all used implants. Finally, Zirconia, CFP 30%, and CFP 60% implants can be used as substitutes for titanium in chest wall reconstruction to restore damaged portions of the ribs and cartilage. However, stiff alumina implants and soft PEEK & PE implants were not recommended for use as they were susceptible to fracture under impact force.

Whole exome sequencing reveals genetic landscape associated with left ventricular outflow tract obstruction in Chinese Han population.

Left ventricular outflow tract obstruction (LVOTO), a major form of outflow tract malformation, accounts for a substantial portion of congenital heart defects (CHDs). Unlike its prevalence, the genetic architecture of LVOTO remains largely unknown. To unveil the genetic mutations and risk genes potentially associated with LVOTO, we enrolled a cohort of 106 LVOTO patients and 100 healthy controls and performed a whole-exome sequencing (WES). 71,430 rare deleterious mutations were found in LVOTO patients. By using gene-based burden testing, we further found 32 candidate genes enriched in LVOTO patient including known pathological genes such as GATA5 and GATA6. Most variants of 32 risk genes occur simultaneously rather exclusively suggesting polygenic inherence of LVOTO and 14 genes out of 32 risk genes interact with previously discovered CHD genes. Single cell RNA-seq further revealed dynamic expressions of GATA5, GATA6, FOXD3 and MYO6 in endocardium and neural crest lineage indicating the mutations of these genes lead to LVOTO possibly through different lineages. These findings uncover the genetic architecture of LVOTO which advances the current understanding of LVOTO genetics.

Stabilizing α-FAPbI3 at FAPbI3/SnO2-X Interface By Reducing Oxygen Vacancies in SnO2-X

CH3NH3PbI3 (CH3NH3 + is denoted MA hereinafter) was selected as the photoactive material in the early stage of perovskite solar cell (PSC) research. However, MAPbI3 shows poor thermal stability due to high volatility of the MA organic cation. Replacing the MA organic cation with a CH(NH2)2 + (CH(NH2)2 + is denoted FA hereinafter) organic cation was suggested to resolve the thermal stability issue. Additionally, FAPbI3 holds higher potential for high-efficiency solar cells with a broader photoresponse range in the solar spectrum than MAPbI3. However, fabricating FAPbI3 thin films is more challenging than MAPbI3. FA exhibits a larger ionic size (2.56 Å) than MA (2.17 Å), making incorporation of FA into PbI6 octahedra difficult. Incorporating FA induces tilting of PbI6 octahedra, which causes reversible deformation of perovskite-phase FAPbI3 (α-phase) into unfavorable phases (δ-phase and PbI2) at room temperature. Several reports on stabilizing the α-phase of FAPbI3, such as through heterogeneous cation or anion mixing, have been presented. For example, mixing smaller ions such as MA, Cs, and Br reduces the unit cell volume of FAPbI3, enhancing hydrogen bonding between FA and the PbI6 octahedron. This hydrogen bonding prevents reversible deformation of and stabilizes the α-phase of FAPbI3 in ambient atmosphere. In conventional PSCs, the perovskite layer usually forms an interface with an electron or hole transport layer (ETL or HTL). The compatibility of materials forming the interface is significant for separating charges from the perovskite with minimal loss. Nevertheless, although stabilizing FAPbI3 in a bulk manner is widely studied, stabilizing FAPbI3 at the interface is relatively overlooked. Stabilizing FAPbI3 at the interface is more important since the interface contains a high portion of structural defects compared to the bulk, almost 100-fold. Unfavorable phases, such as δ-phase FAPbI3 and PbI2, formed at the interface will hinder the charge extraction process from FAPbI3 to the transport layer, similar to defects. Especially, in the n-i-p structure, the perovskite is epitaxially deposited over the ETL, and tuning the interface after deposition is nearly impossible, which stresses the importance of the surface structure of the ETL. In the case of FAPbI3/SnO2-x, Sn and O are the key atoms for stabilizing the PbI6 octahedron and organic cation, respectively, which affects the growth of the perovskite at the interface. Oxygen vacancies in the surface of SnO2-x can cause distortion of the perovskite structure at the interface, inducing unfavorable phases, such as the δ-phase, PbI2, or other unknown phases. Furthermore, oxygen vacancies are more prevalent issue in SnO2-x than TiO2-x due to the stronger multivalency of Sn, which further emphasizes control of oxygen vacancies in SnO2-x. Since the open-circuit voltage (Voc) and fill factor (FF) show greater potential for improvement than the short-circuit current density (Jsc), stabilizing α-FAPbI3 at the interface may be a necessary step for researchers to further increase the power conversion efficiency (PCE) and stability of PSCs. In this work, we systematically studied the formation of δ-phase FAPbI3 and PbI2 induced by oxygen vacancies of the SnO2-x surface at the FAPbI3/SnO2-x interface. Using X-ray diffraction (XRD) and transmission electron microscopy (TEM), we observed PbI2 segregation and δ-phase FAPbI3 formation adjacent to SnO2-x. The generation of iodine interstitials at the interface was revealed as the driving force of the unfavorable phase transition. The absence of oxygen atoms interacting with tin atoms lowered the energy barrier for iodine interstitial generation almost by half, and the iodine interstitials accelerated the unfavorable phase transition of FAPbI3. For the first time, organic cation loss at the FAPbI3/SnO2-x interface was also observed as a severe drawback to forming an ideal heterojunction. Oxygen vacancies in the SnO2-x surface, which act as hydrogen bonding sites for FA cations, induced withdrawal of FA cations, which was revealed by X-ray photoelectron spectroscopy (XPS) measurements. Inspired by this phenomenon, we fabricated a SnO2-x layer with reduced oxygen vacancies by using oxidized black phosphorus quantum dots (O-BPs). The multiple P=O bonds of O-BPs effectively assisted the formation of a SnO2-x layer with minimal oxygen vacancies. After P=O passivation, most of the detrimental effects were mitigated, showing highly stable α-FAPbI3 crystal structures. Consequently, we achieved a maximum PCE of 23.43% with enhanced thermal and operational stability.

A Software Verification Method for the Internet of Things and Cyber-Physical Systems

With the proliferation of the Internet of Things devices and cyber-physical systems, there is a growing demand for highly functional and high-quality software. To address this demand, it is crucial to employ effective software verification methods. The proposed method is based on the use of physical quantities defined by the International System of Units, which have specific physical dimensions. Additionally, a transformation of the physical value orientation introduced by Siano is utilized. To evaluate the effectiveness of this method, specialized software defect models have been developed. These models are based on the statistical characteristics of the open-source C/C++ code used in drone applications. The advantages of the proposed method include early detection of software defects during compile-time, reduced testing duration, cost savings by identifying a significant portion of latent defects, improved software quality by enhancing reliability, robustness, and performance, as well as complementing existing verification techniques by focusing on latent defects based on software characteristics. By implementing this method, significant reductions in testing time and improvements in both reliability and software quality can be achieved. The method aims to detect 90% of incorrect uses of software variables and over 50% of incorrect uses of operations at both compile-time and run-time.

Effects of Polycrystalline Silicon Plug Defect on DRAM Characteristics

This study first demonstrates the effect of polycrystalline silicon plug defects, including voids and seams in dynamic random access memory (DRAM) storage node contact (SNC), on product characteristics. The defect portion of SNC has increased continually due to a reduction in the contact area, an increase in the doping concentration, and low-pressure chemical vapor deposition (LPCVD) process limitations. We validate the effect through defect removal experiments. Numerous methods, such as the cyclic deposition/etch/deposition process of silicon, ion implantation, and laser annealing, are used. The experiments are successful without any side effects using a high-density laser annealing process. The contact resistance of the sample-removed polysilicon defect decreases by 59% and the cell drain current increases by 6%. In addition, the overlap capacitance of the drain node and cell gate edge (Cov) variations by the SNC dopant diffusion forming the source and drain junction of the cell transistor is improved by 6%. Finally, we conduct the row precharge delay from the last data-in (tRDL) time delay reliability test using mass production test technology and it was confirmed that the contact area standard that satisfies the product quality target is improved by 10%. We propose a new direction for polycrystalline silicon SNC development for a sub-20-nm DRAM device based on this experiment.

Fancm has dual roles in the limiting of meiotic crossovers and germ cell maintenance in mammals

Meiotic crossovers are required for accurate chromosome segregation and producing new allelic combinations. Meiotic crossover numbers are tightly regulated within a narrow range, despite an excess of initiating DNA double-strand breaks. Here, we reveal the tumor suppressor FANCM as a meiotic anti-crossover factor in mammals. We use unique large-scale crossover analyses with both single-gamete sequencing and pedigree-based bulk-sequencing datasets to identify a genome-wide increase in crossover frequencies in Fancm-deficient mice. Gametogenesis is heavily perturbed in Fancm loss-of-function mice, which is consistent with the reproductive defects reported in humans with biallelic FANCM mutations. A portion of the gametogenesis defects can be attributed to the cGAS-STING pathway after birth. Despite the gametogenesis phenotypes in Fancm mutants, both sexes are capable of producing offspring. We propose that the anti-crossoverfunction and role in gametogenesis of Fancm are separable and will inform diagnostic pathways for human genomic instability disorders.

An optimization approach for studying the effect of lattice unit cell's design-based factors on additively manufactured poly methyl methacrylate cranio-implant

In craniomaxillofacial surgery the inclusion of lattice structure on the Cranio-implants for the surgical procedure of cranial defects is difficult. Additive manufacturing open ups a huge space for the development of intricate profiles for complex surgical practices. Designing lattice structures with various design topologies has gained more interest in the medical community for reducing the weight of the implants in the cranial region. This research proposes the mimicking of cranial defective portion concerning bone-like porous structure by means of Poly methyl methacrylate (PMMA) material via 3D printing technology. The experiments were optimized by incorporating square-type porous lattice structure in the development of cranial implants. The design-based factors of the unit cell were enhanced with the aid of the Design of experiments (DOE) technique. L9 orthogonal array is developed by incorporating various design-based factors of the lattice unit cell like unit cell size (mm), skewing angle (°), wall thickness (mm), and unit cell orientation (°). The experiments are optimized with respect to obtaining better compressive strength and compressive strength/density of the prepared lattice structure incorporated polymeric samples. The result shows that for obtaining the maximum compressive strength in the porous square lattice-structured PMMA compression samples will be a lower cell size of 2 mm, a higher skewing angle of 30°, a higher wall thickness of 1 mm, and a unit cell orientation of 90°. The experimental optimized condition results of the design-based factors achieve the maximum compressive strength and compressive strength/density of 83.37 MPa and 189.73 MPa/g mm−3. The lattice structure orientated with 90° has a significant contribution towards reducing the development of structural deviations of incorporating square lattice structure on the PMMA polymeric material. Therefore, the topologically modified square lattice structure incorporated 3D printed PMMA material has a potential scope for the replacement of conventional maxillofacial cranial implants.

Internal defect detection and characterization of samarium-cobalt sintered magnets by ultrasonic testing technique

Excessive quantities of samarium-cobalt (Sm-Co) magnet material are being scrapped needlessly due to a lack of understanding of inhomogeneity distribution and unacceptable internal defects. If there is a way to identify, locate, characterize and when needed separate the defective portions of magnet material, utilization can be increased and product quality improved. Further, the magnets’ magnetic and mechanical performance can be improved by reducing the occurrence of internal defects. This paper reports on a cost-effective and efficient nondestructive evaluation method based on an ultrasonic testing (UT) technique applied for detecting and characterizing internal defects in Sm-Co sintered magnets. Applying the UT technique will allow users to comprehensively analyze internal defects, such as inclusions, porosity, microcracks, and other structural irregularities, check for homogeneity and anomalous regions and give the locations of these internal anomalies and defects within the Sm-Co sintered magnets. The UT technique can also be applied to other rare-earth permanent magnets, such as sintered or die-upset neodymium-iron-boron (Nd-Fe-B) magnets. The UT technique can effectively guide quality control and acceptable product selection, in addition to optimizing the magnet alloy design and production processes. Thus, it can facilitate the improvement of magnet manufacturing efficiency and machinability, reduce scrap, prolong service life, increase the use of what would be post-production waste, and enhance product reuse and recycling at end-of-life disposition.

Low-temperature ozone treatment for p-xylene perm-selective MFI type zeolite membranes: Unprecedented revelation of performance-negating cracks larger than 10 nm in polycrystalline membrane structures

We report that low-temperature ozone calcination allowed MFI type polycrystalline zeolite membranes to maximize their p-/o-xylene separation factor (as high as ca. 2000) by suppressing defect formation. Conventional high-temperature calcination and rapid thermal processing, which provide poor and marked p-/o-xylene separation abilities, respectively, were used for comparison. The corresponding defect structures were quantitatively analyzed by image processing of fluorescence confocal optical microscopy images combined with membrane permeation modeling, revealing the main defects (grain boundary defects and cracks) and their tortuosity, porosity, and size. To the best of our knowledge, we, for the first time, demonstrated that in contrast to common belief, the minor portion of wider cracks instead of the major portion of narrower grain boundary defects determined the final permeation rates. Specifically, the MFI membrane prepared by high-temperature calcination contained many grain boundary defects (narrow; ca. 1 nm) and few cracks (wide; ca. 20 nm) that accounted for ca. 0.1% and 99.8%, respectively, of the slowly permeating o-xylene molar flux. In contrast, the ozone-treated MFI membranes, which only possessed grain boundary defects, achieved the high p-/o-xylene separation performance, underlining the need for the selective reduction in the number of wider cracks rather than ubiquitous, narrow grain boundary defects.

Ultrasonic measurements of grouted tendon ducts in the concrete structure using Elop Insight Scanner

Infrastructures such as bridges, tunnels, dams, retaining walls, docks, parking garages and buildings are constructed from reinforced concrete. These structures deteriorate due to cyclic temperature and loading variations, aging, as well as physical causes such as accidents and aggressive chemical attack from the environment. Post tension tendon ducts commonly used in bridges are filled with grout and steel tendons. The voids in the grout inside the tendon ducts can occur due various reasons such as improper filling, material mixing, blockage due to tendons etc. The water can penetrate in these voids inside the tendon ducts which can initiate corrosion. It is therefore vital to detect voids/ unfilled or defective portions of the tendon ducts at an early stage of the construction phase to ensure the strength and safety of the structure. Different types of NDT (Non-Destructive Testing) methods are frequently used for monitoring such infrastructures during regular operation to prevent failure, increase life span and improve safety. One of these NDT techniques, ultrasonic testing, is relatively simple in operation and gives more accurate description of air pockets, voids, cracks, and delaminations in the concrete structures compared to other NDT methods. ELOP has developed a rolling ultrasonic scanner COBRI (COncrete and BRidge Inspection) together with a complete software solution for asset management of structures for faster and better inspection and monitoring of the internal condition of the concrete. It will provide asset owners with information about when, where and how to inspect, maintain and more accurately assess damages and overall condition of their structures. The COBRI scanner contains an array of transducers assembled in two separate rollers used in pitch-catch mode. It uses a patented elastomer solution to provide dry coupling to the concrete surface during scanner movement, without the need for any added fluid couplant. The system uses SAFT (Synthetic Aperture Focusing Technique) algorithm for image reconstruction to increase image quality and signal to noise ratio. It will provide users with improved tomographic (B, C and D-scan) image quality and 3D imaging. In the current work, we have used the COBRI scanner to explore its ability to image grouting defects inside tendon ducts used in concrete structures. The concrete specimen used in the evaluation has two tendon ducts positioned at 8 cm from the top surface with dimensions of 70 cm in length, 55 cm in width and 25 cm in thickness with average aggregate size of 22 mm. One of the tendon ducts is completely empty. The second one is half-length fully filled with grouting along the prestressed steel and other half only three quarters filled, leaving an air cavity on the top. The scanner is rolled approximately 50 cm over the concrete surface and the tomographic (B, C and D-scan) SAFT images are generated at different locations of the concrete specimen together with a 3D volume image. The results showed that the COBRI scanner is able to differentiate the filled and partially filled tendon ducts in the concrete structure. As COBRI is a rolling ultrasound scanner, it will help the bridge owners to scan and assess the grouting defects in the tendon ducts much more efficiently than other scanners available in the market.

Research on improvement of defect detection accuracy by resonance judgment for noncontact acoustic inspection method by acoustic irradiation-induced vibration

Noncontact acoustic inspection methods using acoustic irradiation-induced vibration and laser Doppler vibrometer that can perform defect exploration from a distance are being studied. This method has the feature that it can measure a wide range of measurement objects such as composite materials used for aerospace as well as concrete structures such as tunnels and bridges without contact. From the experimental results, it was found that the increase in noise level due to the decrease in the return light of the laser due to the condition of the measurement surface causes a decrease in the estimation accuracy of defect exploration. Therefore, it has been clarified that the detection accuracy of the defect position can be improved by devising a resonance judgement process for discriminating the signal and noise due to the resonance of the defect portion.

The Analysis of Lean Manufacturing in Waste Reduction During Rosin Ester Production at PT XYZ

Waste are commonly generated during the utilization of raw materials. Therefore, they are become important to consider lean manufacturing to achieve the overall business objectives. PT XYZ is a major company in processing pine resin and its derivatives, including gum rosin, turpentine and rosin ester, mainly used as featured commodities. During production, a certain amount of unwanted materials in the form of defect and in the form of work-in-process (WIP) that caused waiting wastes are obtained, particularly at the rosin ester floor. This study aims to identify the waste types and their dominant factors that caused waste occurred in PT XYZ, as well as recommend improvement strategies in boosting production efficiency. Based on the identification results, two dominant wastes occurred in the form of defects and waiting. The defect and scrap portions were prevalent in gum rosin drops, flakes, brushed dust and products that did not fulfill color and size specifications at 63.72 kg/shift that equal to 2,08% scrap rate per shift. Meanwhile, waiting waste refers to work-in-process (WIP) on Oleo Pine Resin (OPR) storage and delay interval for a complete sampling process. The WIP circumstance was also observed at the packaging workstation. Furthermore, repairing tank leaks, allocating special workers to flaking workstations, extending workers’ supervision, combining flake cooling and transportation processes, procuring cooling conveyors and increasing the quantity of esterification reactors were recommendations for optimum production. These proposed activities have the capacity to enhance the process cycle efficiency (PCE) value from 4.65 to 6.34%.

Management of Two Unusual Patients With Vascular Anomalies

Vascular anomalies form a significant portion of congenital defects and venous malformations are the most prevalent type among adults. Multiple imaging modalities have been proposed for pre-operation assessments. Although some studies have reported Magnetic Resonance Imaging (MRI) as the most valuable modality, in many situations, CT scan remains the equipment of choice due to its availability. In each case, a precise assessment of the malformation is needed. In two cases mentioned in our study, prior to the operations, only a monophasic CT scan was performed that resulted in missing evidence of severity and extent of venous malformation. One of the imaging procedures is a three-phase CT scan. Although in the monophasic CT scans, a delay of 65 seconds is applied, in three-phase CT, both filling in and washing out are notable, which gives three-phase CT a more predictive value about flow pattern over monophasic CT.

Reliability of non-destructive sonic tomography for detection of defects in old Zelkova serrata (Thunb.) Makino trees

Zelkova serrata (Thunb.) Makino trees, which account for a large proportion of cultural assets and protected trees and have considerable historical and cultural symbolic meaning in South Korea. To verify the reliability of the nondestructive sonic tomography (SoT) method on Z. serrata trees, this study compared the results of SoT with those obtained with the destructive resistance micro-drilling method. With SoT measurement, defects were found in approximately 75% of the target Z. serrata trees and two of these trees were evaluated as having a high risk because their defective portions accounted for approximately 70% or more of the entire cross section. The independent samples t-test indicated that the two methods did not show a significant difference between measurements. Regression analysis indicated that the measurement values of the two methods showed a positive relationship with a high explanatory power of 76%, thus, verifying the reliability of SoT.

PROSTHETIC REHABILITATION OF A MAXILLECTOMY PATIENT WITH A TITANIUM CLOSED HOLLOW BULB OBTURATOR USING LOST WAX BOLUS TECHNIQUE - A CASE REPORT

Maxillary intraoral defects due to surgical resection create an open link between the oral and nasal cavities causing difficulty in deglutition, speech, and an unaesthetic appearance . Maxillary obturator prosthesis is a more frequent treatment modality than surgical reconstruction for maxillectomy in patients suffering from oral cancer. The obturators often become heavy and hence are hollowed out in the defect portion to reduce its weight as a standard practice. This case report describes the prosthetic rehabilitation of a maxillectomy patient with a titanium cast hollow obturator using lost wax bolus technique.

Optimal pricing and ordering policy for defective items under temporary price reduction with inspection errors and price sensitive demand

<p style='text-indent:20px;'>This paper studies the retailer's optimal promotional pricing, special order quantity and screening rate for defective items when a temporary price reduction (i.e., TPR) is offered. Although previous studies have examined the similar issue, they assume a constant demand and an error-free screening process. A subversion of these two assumptions differentiates our paper. First, using a price-sensitive demand, we analyze that the original screening rate may be insufficient, and propose the CPD (i.e., control the promotional demand) and the ISR (i.e., increase the screening rate through investment) strategy to handle it. Second, we incorporate both Type I and Type II inspection errors into our model. Then we establish an inventory model aiming to maximize the retailer's profit under CPD and ISR, respectively. Finally, numerical examples are conducted and several results are obtained: (1) a higher portion of defects makes ISR more profitable; (2) both a higher probability of a Type I error and a Type II error decrease the profit under CPD and ISR, but a Type I error has a more pronounced negative impact; and (3) comparing with the existing studies with a constant demand, our model generates a higher profit especially in markets with a higher price sensitivity.</p>

Surface Characterization and Conductivity of Two Types of Lithium-Based Glass Ceramics after Accelerating Ageing.

In this study, two different dental ceramics, based on zirconia-reinforced lithium-silicate (LS1) glass-ceramics (Celtra Duo, Dentsply Sirona, Bensheim, Germany) and lithium disilicate (LS2) ceramics (IPS e.max CAD, Ivoclar, Vivadent, Schaan, Liechtenstein) were examined. They were tested prior to and after the crystallization by sintering in the dental furnace. Additionally, the impact of ageing on ceramic degradability was investigated by immersing it in 4% acetic acid at 80 °C for 16 h. The degradability of the materials was monitored by Impedance Spectroscopy (IS), X-Ray Powder Diffraction (XRPD), and Field Emission Scanning Electron Microscope (FE-SEM) techniques. It was detected that LS2 (vs. LS1) samples had a lower conductivity, which can be explained by reduced portions of structural defects. XRPD analyses also showed that the ageing increased the portion of defects in ceramics, which facilitated the ion diffusion and degradation of samples. To summarize, this study suggests that the non-destructive IS technique can be employed to probe the ageing properties of the investigated LS1 and LS2 ceramics materials.

Inclusion-induced fatigue crack initiation in powder bed fusion of Alloy 718

Abstract Fatigue crack initiation of Alloy 718 additively manufactured via electron beam-powder bed fusion (EB-PBF) process was investigated. The melt parameters were chosen to achieve sufficient energy input and minimize process-induced defects. A line offset of 200 µm with enough line energy was used, leading to the formation of wide and deep melt pools. This strategy facilitated the formation of equiaxed grains at the melt pools bottom, and short columnar grains within the melt pools aligned parallel to the build direction. The mixed grain morphology and texture were retained after various thermal post-treatments, including heat treatment (HT), hot isostatic pressing (HIP), and HIP-HT. Micron-sized non-metallic inclusions in the feedstock powder, such as Al-rich oxide and titanium nitride clustered during the EB-PBF process, and remained intact during the post-treatments. Low cycle fatigue cracks mainly originated from the non-metallic inclusions found near the surface of the test specimens. HIPing was able to remove a portion of the internal defects, including round-shaped and shrinkage pores; therefore, a small fatigue life enhancement was observed in HIP-HT compared to HT.

Research and Application of Label Defect Detection Method Based on Machine Vision

For the problems of scratches and false detections such as wrinkles and other defects in the printing process, the HALCON software is used for programming, and the product label defects are detected in real time based on the photometric stereo vision technology. Firstly, by dimming the product labels of four different orientations, different orientation maps are obtained, the illumination map is calculated to obtain the albedo map, and then the four-source photometric stereo technology is used on the basis of the traditional photometric stereo technology. After obtaining the surface gradient information of the tag to be tested, the measurement image is subjected to morphological processing using the gradient information to obtain a curvature image. The curvature image is then image processed. Finally, the defective portion is filtered to effectively segment the surface defect area of the label. This method is implemented using HALCON software and is implemented in conjunction with C# mixed programming.

Clinical outcomes following injections of leukocyte-rich platelet-rich plasma in osteoarthritis patients

BackgroundScientists are trying to discover how to repair cartilage defects in knee osteoarthritis (KOA). In our previous study, we found a fibrocartilage-rich cover over the defective portions of cartilage after administering leukocyte-rich platelet-rich plasma (LR-PRP). This study aimed to investigate the efficacy of multiple injections of LR-PRP for the treatment of KOA and determine an LR-PRP treatment protocol for KOA in actual clinical practice. HypothesisWe hypothesized that using abundant LR-PRP would improve outcomes in patients with KOA. Study designProspective, cross-sectional, interventional, randomized trial. MethodsIntra-articular LR-PRP injections were administered to 50 knees. Patients received six injections of LR-PRP in total, which were administered at 4-week intervals. Patients were evaluated based on clinical outcomes, including visual analog scale (VAS) scores, Knee injury and Osteoarthritis Outcome Scores (KOOS), and magnetic resonance images (MRI) and radiographic findings before treatment and at 3 and 6 months after treatment. We investigated the recurrence of pain and presence/absence of MRI changes. Furthermore, we examined the Outcome Measures In Rheumatology-Osteoarthritis Research Society International (OMERACT-OARSI) responder criteria. ResultsThe mean improvement rate, as assessed by VAS, was 61.6% (P < .0001). Concerning OMERACT-OARSI, 37 of 50 knees (74%) were considered responders. There was a significant difference in the follow-up MRI findings, as assessed by the MRI Osteoarthritis Knee Score for bone marrow lesions (P < .007). No significant difference in osteoarthritis grade was observed. ConclusionOur LR-PRP procedure resulted in 74% of knees being classified as responders, regardless of the degree of knee deformation. Multiple injections of LR-PRP was effective for advanced grades of KOA. Thus, based on the results of our study, we believe that LR-PRP should be implemented as an additional conservative treatment option for non-operative management of OA. Trial registrationJapan Medical Association Center for Clinical Trials (JMA-XXX).