Material Breakage Research Articles

Dual-channel mechano-phosphorescence: a combined locking effect with twisted molecular structures and robust interactions

Organic mechanoluminescence materials, featuring dual emission and ultralong phosphorescence characteristics, exhibit significant potential for applications in real-time stress sensing, pressure-sensitive lighting, advanced security marking techniques, and material breakage monitoring. However, due to immature molecular design strategies and unclear luminescence mechanisms, these materials remain rarely reported. In this study, we propose a valuable molecular design strategy to achieve dual-channel mechano-phosphorescence. By introducing the arylphosphine oxide group into a highly twisted molecular framework, enhanced intra- and intermolecular interactions could be achieved within rigid structures, leading to dual-channel mechanoluminescence with greatly promoted ultralong phosphorescence. Further investigations reveal the substantial boosting effect of intra- and intermolecular interactions on mechanoluminescence and ultralong phosphorescence properties by locking the highly twisted molecular skeleton. This work provides a concise and guiding route to develop novel smart responsive luminescence materials for widespread applications in material science.

Analysis and quantification of double-stranded DNA breaks in blood lymphocytes by detection of γ-H2AX foci during a body mass increase

The research aims to investigate the relationship of body mass index indicators on the appearance and nature of damage to the genetic material of lymphocyte cells in patients with diagnosed obesity without concomitant pathological conditions. The research methods included anthropometry, biochemical blood examination, immunofluorescence analysis, and static data processing. Characterization of nuclear damage was assessed by studying the phosphorylated histone protein γ-H2AX loci in circulating lymphocytes (computational tool – AKLIDES). The study sample comprised 235 adult patients, categorized into four groups based on body mass index, with randomization conducted for age and sex matching between the groups. BMI increased with higher degrees of obesity. DNA damage in lymphocytes showed significant differences among groups, particularly in overweight patients. Correlations between BMI and various DNA damage indices suggest a relationship between body weight and genetic material breakage in circulating lymphocytes. The analysis of the data revealed that the number of deoxyribonucleic acid double-strand breaks per lymphocyte as well as the number of nuclei with break foci and the break diameter itself correlated with the body mass index and in some cases with the waist/hip index as well as the waist/height index. The results of the work can be used to improve treatment protocols for obese patients, as well as implemented in preventive programs to prevent the development of overweight and type 2 diabetes mellitus.

Fluid-structure interaction study on the causes of mending material damage after sigmoid sinus wall reconstruction

Background and objectiveSigmoid Sinus (SS) Wall Reconstruction (SSWR) is the mainstream treatment for pulsatile tinnitus (PT), but it has a high risk of recurrence. The damage of mending material is the key cause of recurrence, and its hemodynamic mechanism is still unclear. The purpose of this study was to investigate the hemodynamic causes of mending material breakage. MethodsIn this study, six patient-specific geometric models were reconstructed based on the data of the computed tomography angiography (CTA). The transient fluid-structure coupling method was performed to clarify the hemodynamic state of sigmoid sinus and the biomechanical state of the mending material. The distribution of stress and displacement and the flow pattern were calculated to evaluate the hemodynamic and biomechanics difference at the mending material area. ResultsThe area of blood flow impact in some patients (2/6) was consistent with the damaged location of the mending material. The average stress (6/6) and average displacement (6/6) of damaged mending material were higher than those of complete mending material. All (6/6) patients showed that the high-stress and high-displacement proportion of the DMM region was higher than that of the CMM region. Moreover, the average stress fluctuation (6/6) and average displacement (6/6) fluctuation degree of damaged mending material is larger than that of complete mending material. ConclusionsThe impact of blood and the uneven stress and displacement fluctuation of the mending material may be the causes of mending material damage. High stress and high displacement might be the key causes of the mending material damage.

Implant breakage after shoulder arthroplasty: a systematic review of data from worldwide arthroplasty registries and clinical trials

BackgroundImplant breakage after shoulder arthroplasty is a rare complication after aseptic loosening, infection or persistent pain, resulting in malfunction of the components requiring revision surgery. This correlates with a high burden for the patient and increasing costs. Specific data of complication rates and implant breakage are available in detailed arthroplasty registries, but due to the rare occurrence and possibly underestimated value rarely described in published studies. The aim of this systematic review was to point out the frequency of implant breakage after shoulder arthroplasty. We hypothesized that worldwide arthroplasty registry datasets record higher rates of implant breakage than clinical trials.MethodsPubMed, MEDLINE, EMBASE, CINHAL, and the Cochrane Central Register of Controlled Trials database were utilized for this systematic review using the items “(implant fracture/complication/breakage) OR (glenoid/baseplate complication/breakage) AND (shoulder arthroplasty)” according to the PRISMA guidelines on July 3rd, 2023. Study selection, quality assessment, and data extraction were conducted according to the Cochrane standards. Case reports and experimental studies were excluded to reduce bias. The breakage rate per 100,000 observed component years was used to compare data from national arthroplasty registries and clinical trials, published in peer-reviewed journals. Relevant types of shoulder prosthetics were analyzed and differences in implant breakage were considered.ResultsData of 5 registries and 15 studies were included. Rates of implant breakage after shoulder arthroplasty were reported with 0.06–0.86% in registries versus 0.01–6.65% in clinical studies. The breakage rate per 100,000 observed component years was 10 in clinical studies and 9 in registries. There was a revision rate of 0.09% for registry data and 0.1% for clinical studies within a 10-year period. The most frequently affected component in connection with implant fracture was the glenoid insert.ConclusionClinical studies revealed a similar incidence of implant failure compared to data of worldwide arthroplasty registries. These complications arise mainly due to breakage of screws and glenospheres and there seems to be a direct correlation to loosening. Periprosthetic joint infection might be associated with loosening of the prosthesis and subsequent material breakage. We believe that this analysis can help physicians to advise patients on potential risks after shoulder arthroplasty.Level of evidenceIII.

Incidence of secondary displacement after osteosynthesis of proximal humerus fractures: a retrospective study of 185 cases.

Proximal humerus fractures are the third most common fracture in patients over 65 years of age. There is no clear consensus regarding their treatment. The objective of this retrospective observational study was to calculate the incidence of secondary displacement after osteosynthesis of these fractures and to identify possible risk factors. 185 cases were reviewed and all osteosynthesized fractures between January 2008 and December 2016 were included. Data collected included age, sex, body mass index, alcohol and tobacco use, bone mineral density of the proximal humerus, fracture type, initial displacement, management time, type of treatment, surgeon's experience and expertise, and postoperative reduction quality. A radiographic follow-up was done at least 3 months following the fracture (until consolidation). The definition of secondary displacement was: varus/valgus displacement >10°, tuberosity translation >5 mm, articular effraction or material breakage. 53 secondary displacements were found, with an incidence of 28.6%. Seventy-two percent were diagnosed at the first follow-up visit, which occurred at an average of 29 days postoperatively. Among all factors studied, only two were statistically significant for secondary displacement: 1) low proximal humeral bone density (defined by a Tingart index <4) appears to be a risk factor, with a calculated relative risk of 2.71 (p = 0.04); and 2) the operator's specialization in the upper limb appears to be a protective factor, with a relative risk of 0.27 (p = 0.01). A similar high incidence of complications after osteosynthesis of the proximal humerus is found in the literature, confirming the difficulty in managing these fractures. More attention should be given to patients with low bone density.

Which non-infection related risk factors are associated with impaired proximal femur fracture healing in patients under the age of 70 years?

Background/purposeImpaired healing is a feared complication with devastating outcomes for each patient. Most studies focus on geriatric fracture fixation and assess well known risk factors such as infections. However, risk factors, others than infections, and impaired healing of proximal femur fractures in non-geriatric adults are marginally assessed. Therefore, this study aimed to identify non-infection related risk factors for impaired fracture healing of proximal femur fractures in non-geriatric trauma patients.MethodsThis study included non-geriatric patients (aged 69 years and younger) who were treated between 2013 and 2020 at one academic Level 1 trauma center due to a proximal femur fracture (PFF). Patients were stratified according to AO/OTA classification. Delayed union was defined as failed callus formation on 3 out of 4 cortices after 3 to 6 months. Nonunion was defined as lack of callus-formation after 6 months, material breakage, or requirement of revision surgery. Patient follow up was 12 months.ResultsThis study included 150 patients. Delayed union was observed in 32 (21.3%) patients and nonunion with subsequent revision surgery occurred in 14 (9.3%). With an increasing fracture classification (31 A1 up to 31 A3 type fractures), there was a significantly higher rate of delayed union. Additionally, open reduction and internal fixation (ORIF) (OR 6.17, (95% CI 1.54 to 24.70, p ≤ 0.01)) and diabetes mellitus type II (DM) (OR 5.74, (95% CI 1.39 to 23.72, p = 0.016)), were independent risk factors for delayed union. The rate of nonunion was independent of fracture morphology, patient’s characteristics or comorbidities.ConclusionIncreasing fracture complexity, ORIF and diabetes were found to be associated with delayed union of intertrochanteric femur fractures in non-geriatric patients. However, these factors were not associated with the development of nonunion.

Trochanteric fracture pattern is associated with increased risk for nonunion independent of open or closed reduction technique

PurposeSoft tissue injury and soft tissue injury as risk factors for nonunion following trochanteric femur fractures (TFF) are marginally investigated. The aim of this study was to identify risk factors for impaired fracture healing in geriatric trauma patients with TFF following surgical treatment with a femoral nail.MethodsThis retrospective cohort study included geriatric trauma patients (aged > 70 years) with TFF who were treated with femoral nailing. Fractures were classified according to AO/OTA. Nonunion was defined as lack of callus-formation after 6 months, material breakage, and requirement of revision surgery. Risk factors for nonunion included variables of clinical interest (injury pattern, demographics, comorbidities), as well as type of approach (open versus closed) and were assessed with uni- and multivariate regression analyses.ResultsThis study included 225 geriatric trauma patients. Nonunion was significantly more frequently following AO/OTA 31A3 fractures (N = 10, 23.3%) compared with AO/OTA type 31A2 (N = 6, 6.9%) or AO/OTA 31A1 (N = 3, 3.2%, p < 0.001). Type 31A3 fractures had an increased risk for nonunion compared with type 31A1 (OR 10.3 95%CI 2.2 to 48.9, p = 0.003). Open reduction was not associated with increased risk for nonunion (OR 0.9, 95%CI 0.1 to 6.1. p = 0.942) as was not the use of cerclage (OR 1.0, 95%CI 0.2 to 6.5, p = 0.995). Factors such as osteoporosis, polytrauma or diabetes were not associated with delayed union or nonunion.ConclusionThe fracture morphology of TFF is an independent risk factor for nonunion in geriatric patients. The reduction technique is not associated with increased risk for nonunion, despite increased soft tissue damage following open reduction.

EBRA Migration Analysis of a Modular, Distally Fixed Stem in Hip Revision Arthroplasty: A Clinical and Radiological Study.

Background: Massive osteolysis of the proximal femur makes stem revision a challenging procedure. EBRA-FCA provides the opportunity to determine stem migration, which is considered a predictive factor for implant survival. In this study, we aimed to analyze the migration behavior of a modular, distally fixed reconstruction prosthesis. Methods: Applying a retrospective study design, we reviewed all consecutive patients who received a cementless MP reconstruction prosthesis (Waldemar Link GmbH & Co. KG, Hamburg, Germany) at our Department between 2005 and 2019. We reviewed medical histories and performed radiological measurements using EBRA-FCA software. Results: A total of 67 stems in 62 patients (female 26; male 36) fulfilled our inclusion criteria. Mean age at surgery was 68.0 (range 38.7–88.44) years. EBRA migration analysis showed a median subsidence of 1.6 mm (range 0.0–20.6) at 24 months. The angle between stem and femur axis was 0.3° (range 0.0°–2.9°) at final follow-up. No correlation between body mass index and increased subsidence was found (p > 0.05). Overall revision-free rate amounted to 92.5% and revision-free rate for aseptic loosening to 98.5%. Furthermore, no case of material breakage was detected. Conclusions: In summary, the MP reconstruction prosthesis showed low subsidence and reduction in the migration rate over the investigated follow-up. Based on this, the modular stem can be considered as a good therapy option in challenging stem revisions offering various options to address the individual anatomical situation.

On the use of sacrificial layer in ECDM process for form accuracy

During the electrochemical discharge machining (ECDM) process, major imperfections on work material occurs due to stray cutting caused by thermal energy. Some of these are re-solidification, melt flow over, thermal splashes, micro-cracks, work material breakage, hole over cut (HOC), and sudden taper. These thermal deteriorations are inherent in thermal-based processes like the ECDM process. Post-processing of these machined features at micron-level on glass material is a challenging task. To overcome this issue, in the present article, the depth up to which thermal damages occurred was predicted at given input energy conditions and the same thickness of glass wafer was bonded over the work material during machining. In order to find out the thickness, a pressurized tool feeding and dial gauge attachment was designed. Using this attachment, instantaneous depth was measured at every second of machining time and effective energy supplied to each plane of the work material was calculated analytically. The same was imported in to COMSOL Multiphysics software for simulating the heat flux gradient and temperature distribution on each plane of the work material. Using the simulation data, the depths from the hole entrance that are more prone to thermal deteriorations was identified. This depth was considered as critical depth for respective input energy conditions. Applied voltage, pulse on time, and glass wafer thickness were considered as input parametric conditions, and machined hole depth, HOC, and hole quality on work material were considered as output characteristics. Experiments were performed with various parametric conditions, and it was observed that the glass wafer carried away the major thermal deteriorations and leaving minimal damages on the work material. At the optimal parametric conditions, HOC was reduced by 71.5% and hole quality was improved significantly. Application of glass wafer compromises around 39% hole depth.

Interface functional groups protected by confinement effect for flexible supercapacitor and capacitive deionization

Biomass, as one of the most promising carbon precursors, mainly focuses on its special original nanostructures at present. However, the biological diversity and uncontrollability are not conducive to its application in high-precision fields. In this work, the biomass, separated into soluble substances, are applied to the multi-cavity nanospheres (NC-PPD) and ultra-thin nanosheets (BC-PPD) modified by functional group (p-phenylenediamine) interface, thus without depending on their original morphology. On account of similar carbon components from the same precursor, the single-factor function relation, the confinement effect on surface functional groups and its influence law in flexible supercapacitor (SC) and capacitive deionization applications, are studied in detail. Overall, the interface modification optimizes the hydrophilicity of the material, increases its actual reachable specific surface area and pseudocapacitance contribution. Most importantly, the confinement effect enhances the stability of surface functional groups, and reduces the material damage from capacitive reaction (retains 80.2% initial capacitance after 104 cycles). Moreover, the multi-chamber structure strengthens the material stability and alleviates the adverse effects of material breakage. For SC, the NC-PPD//NC-PPD device provides large energy density of 8.8 Wh kg−1 and maximum power density of 2.5 k W kg−1. For CDI, salt adsorption capacity can be up to 33.2 mg g−1.

Inverse estimation method for internal defects based on surface stress of carbon-fiber-reinforced plastics using machine learning

Carbon-fiber-reinforced plastic (CFRP) is a composite material whose base material is plastic and reinforcement material is carbon fibers. CFRP is widely used in various fields for laminating prepregs. The laminated plate tends to sustain damage, such as delamination, fiber breakage, and base material breakage; hence, we must conduct high-precision and efficient nondestructive testing (NDT). Examples of NDT are ultrasonic examination, X-ray tomography, and infrared stress analysis. With most NDT methods, it is difficult to easily obtain detailed correct information of defects, such as their depth, position, and size. To solve this problem, we develop a machine-learning-aided inverse analysis model that predicts the spatial information of defects from the sum of the principal stresses on the surface calculated from the temperature change measured by infrared analysis, and we propose it as an alternative method to the existing damage analysis. Applying the proposed method to the simulated stress distributions of quasi-isotropic CFRP laminates with defects, the results showed over 99% success to recognize the detail information of defects. Additionally, we examine the properties of the dataset using a forward analysis model and a variational autoencoder. Our method with a convolutional neural network enables us to successfully estimate the information of defects at high speed. Experimental data can be applicable as well as the simulation results to our proposed method, and we believe our method will be a powerful supporting tool for the current NDT for CFRPs.

Understanding the machining characteristic of plain weave ceramic matrix composite in ultrasonic-assisted grinding

The machining of silicon carbide (SiC) ceramic matrix composites is a significant challenge because of the severe material damage that may occur during material removal, which might shorten the service life of the composite parts. In this study, the effects of different fibre orientations of two-dimensional woven carbon-fibre-reinforced silicon carbide matrix composites (2D-C f /SiC) on the grinding force, surface roughness, and surface/subsurface micromorphology were investigated to clarify the material removal and breakage mechanism in ultrasonic-assisted grinding of ceramic matrix composites. The results show that the predominant material removal mode in ultrasonic-assisted grinding is brittle fracture. The forms of material breakage are matrix cracking, fibre fracture, fibre pull-out, interfacial debonding, and interfacial fracture. Compared with conventional grinding, the normal force, tangential force, and surface roughness in ultrasonic-assisted grinding decreased by approximately 20%, 18%, and 9%, respectively. The machining parameters significantly impacted the grinding force and surface roughness. The material removal modes varied for different fibre orientations. Ultrasonic-assisted grinding can effectively decrease the grinding force and improve the surface integrity. The findings of this study can be applied to predict the grinding force and surface integrity of 2D-C f /SiC and contribute to the design and manufacturing of this type of material.

Multi-fidelity kinetic theory-based approach for the prediction of particle attrition: Application to jet cup attrition system

The timescale difference between the “fast” flow dynamics of fluidized bed reactors and the relatively “slow” rate of particle degradation makes the direct computational prediction of attrition challenging. An approach to this challenge is a multi-fidelity strategy where a high fidelity model for the flow dynamics is coupled with a lower fidelity model for the long-time resolution of the bulk attrition of the reactor inventory. We implement this approach using high-fidelity kinetic theory simulations to calculate the flow dynamics which are post-processed to calculate the frequency and intensity of the particle-particle and particle-wall collisions (e.g. collision energy spectra). This is combined with the particle breakage properties to construct the coefficients for a low-fidelity model [e.g. Monazam et al., 2018, Powder Technology 340, p. 528–536]. Simulations are performed of a jet cup attrition system containing Canadian hematite (Monazam et al. 2018). These are first analyzed using the collision energy spectra. Quantitative predictions of the mass loss are made using a low-fidelity model derived from the collision-spectra and a calibrated material breakage coefficient. The results are found to compare favorably with the experimental measurements.

Pyrocarbon implants for the basal thumb arthritis

Silicone implants for the treatment of basal thumb arthritis were first proposed in the 1970’s by Swanson. They became extremely popular and despite good functional results, the high rate of complications such as instability, material breakage and foreign body reactions led to them being progressively abandoned by most surgeons. Pyrocarbon implants were introduced at the beginning of the 2000’s. A large range of different implant models that can be used for either hemiarthroplasty or interposition arthroplasty. For some implants, a supplemental ligamentoplasty procedure is required to avoid instability. Miniaturization of some implants provides new options for minimally invasive surgery, which is relevant in low and medium grades of osteoarthritis, especially for young, active patients. Medium- and long-term follow-up have now been reached by some pyrocarbon interpositions. Their results confirm that these implants are a reliable alternative to other techniques. This paper focuses on the surgical techniques and outcomes of pyrocarbon implants for the treatment of basal thumb arthritis. It is based on published data and the author’s experience.

Assessment of Cases of Complete Denture Fracture.

Background:There are many causes and reasons associated with fractures of complete dentures. The present study assessed case of complete denture fracture.Materials and Methods:One hundred and fifty complete denture wearers reported to the department of prosthodontics for correction of complete denture fracture were examined carefully. The factors such as retention, stability, and occlusal errors were recorded. Cause of denture fracture was recorded too.Results:Out of 150 patients, males were 80 and females were 70. The site of fracture was incisor area in 25, canine area in 30, midline in 50, molar area in 10, and maxillary tuberosity/retromolar pad area in 35 cases. The etiology of denture fracture was accidental fall in 42, poor fit in 28, poor occlusion in 40, material breakage in 25, and acrylic base defect in 15 cases. The difference was statistically significant (P < 0.05).Conclusion:Most common cause of denture fracture was accidental fall, poor fit, poor occlusion, and material breakage.

Research advancements in machining of metal matrix composites through wire electro discharge machining technique

Abstract Wire electric discharge machining, a major variant of electric discharge machining have greater capability to machine complex and intricate shape of conductive materials which cannot be machined by the conventional machining. Metal matrix composite with properties like great wear resistance, ultra lightweight, high specific strength and significant hardness are machined by wire electric discharge machining by the modern researchers. The compositions of metal matrix composites exhibit very significant role on the machining characteristics of this process such as rate of material removal, surface finish, kerf width and breakage of wire etc. A comprehensive understanding of wire electric discharge machining of metal matrix composites are discussed in this article with special attention to the effects of particles. Also, recent modifications in the machining techniques are also mentioned. Finally, the article is concluded with the scope for future work on wire EDM of metal matrix composite.

High Volumetric Energy Density of LiFePO4 Battery Based on Ultrasonic Vibration Combined with Thermal Drying Process

Increasing the compaction density of electrodes is an effective way to increase the volumetric energy density of the full battery. To avoid the problem of low compaction density, material breakage, and porosity decrease during the process of calendering, which greatly deteriorate the electrochemical performance of the battery, in this paper, for the first time, we use ultrasonic vibration-assisted densification technology combining with thermal drying technology to prepare the electrodes. Ultrasonic vibration reduces the friction among the powder particles during the drying process, so that the particles of active materials could aggregate more closely. And then, there are smaller displacements and sliding during the calendering process in ultrasonic vibration-assisted (UV–A) electrode than ordinary ones, which not only avoid the failure of the binder and the shedding of the carbon layer, also increase the number of connection points between material particles. The results show that the UV–A densification technology leads to improved volumetric energy density (increased by 5.3%, 6.6%, 7.6%, 11.6%, 13.4%, and 13.0% compared to the ordinary battery at 0.2C, 0.5C, 1C, 2C, 5C, and 10C, respectively), cycle performance and ion conductivity of full battery.

A Research on Strength Characteristics of Compact Tension Specimens with Heterogeneous Composite Materials Bonded by Adhesives

With CT specimen models of CFRP with cracks and adhesive interfaces, this study aims at investigating the strength characteristics of heterogeneous composite materials bonded by adhesives through the analyses. Even minor cracks or defects that may occur inside a composite material in the manufacturing process can result in the stress concentration, and this will lead to the material breakage. So, we designed CT specimen models with CFRP alone and CFRP with stainless steel or aluminum by using their material properties of CFRP, stainless steel, and aluminum. The simulation analyses were carried out and their strength characteristics were investigated. It is necessary to prepare a way to relieve stress concentration at the stage of design under the assumption those cracks actually occur at manufacturing process. By combining CFRP with stainless steel or aluminum, both of which have good ductility, we found that the deformation and deformation energy increased and the maximum equivalent stress decreased. It is thought that this material can lower the risk of material breakage by changing some of the impact energy which may damage CFRP, into the deformation energy. This deformation energy brings about the good ductility by utilizing stainless steel and aluminum under the situations where the sudden tension and impact loads are expected or applied. The results revealed that when CFRP was combined with the heterogeneous metal, it was possible for CFRP to be used where otherwise it could not be used alone and provided CFRP with better material property and more diverse process-ability So, this composite material can be prevented from breakage in the process of manufacturing and increase the safe use. As CFRP with the rigidity better than metals can be applied to composites, the composites with CFRP can be improved to have better material property and more diverse process-ability

Comparing the Influence of Different Overhand/Underhand Stacking Combinations of Reversing Half-Hitches on Alternating Posts on Arthroscopic Knot Security

Previous literature demonstrated the importance of stacking at least three reversing half-hitches on alternating posts (RHAPs) following arthroscopic knot placement. However, RHAPs construction involves looping the suture in either an "overhand" or an "underhand" manner as it relates to the post, which may affect knot security. This study investigated the presently unidentified influence of different stacking combinations of three RHAPs and suture material on arthroscopic knot security. Four different RHAPs stacking combinations were tied with three different suture materials. Ten knots of each configuration were tied using each suture material, resulting in 120 evaluated knots. A single load-to-failure test was performed. The mode of failure and mean ultimate clinical failure load were recorded. Different overhand/underhand stacking combinations of three RHAPs had a statistically significant effect on arthroscopic knot strength and security; however, all combinations surpassed the minimum ultimate clinical failure threshold. Knots constructed with either Force Fiber® or braided fishing line had mean ultimate clinical failure loads of greater than 200 N and most commonly failed due to suture material breakage (100%, 60 - 80% respectively). Conversely, FiberWire® demonstrated lower mean ultimate clinical failure loads and had a higher incidence of elongated but intact failure (60 - 90%). Different overhand/underhand stacking combinations of three RHAPs yielded an arthroscopic knot capable of secure tissue fixation. A significant effect was observed for suture materials on the knot strength. This study increases our understanding of suitable RHAPs construction following arthroscopic knot placement that can lead to improving the ultimate clinical failure loads of constructed arthroscopic knots observed between orthopedic surgeons.

High-pressure grinding rolls: model validation and function parameters dependency on process conditions

A model for High Pressure Grinding Rolls (HPGR) was developed in this work based on the widely used Population Balance Model (PBM). This approach uses a variety of different functions one of which is the breakage distribution function. The methodology to determine the function parameters is presented and using these values, the model was compared with real processed materials from an HPGR pilot plant, with tungsten ore as the test material. The results of the model parameter determination, and the product of the comminution in the HPGR, showed the dependency of material breakage on the material characteristics, and on the operative and process conditions. The model presented is reasonably robust, showing less error than the 3.0 Root Mean Square Error when compared with a heterogeneous feed particle size distribution material. The operational gap was also studied, and its dependency on the feed particle size, porosity, moisture, and specific pressing force was proven.