Cohesive Components Research Articles

Impacts of potential energy oscillations on the friction of graphene and BN lubricants

Abstract The frictional responses of graphene and boron nitride lubricants is studied from the perspective of the potential energy evolution. At a low normal load regime and high interface adhesion, friction can be effectively characterized by investigating the interfacial energy barrier formation process. By decomposing the energy evolution into strain and interfacial cohesive components, we find that the oscillation phase difference plays an essential role in the friction response and is controlled by the energy conversion between them. Analyses further reveal that the energy oscillations are excited by the vertical motion of the sliding asperity that induces periodic deformation and position changes in the lubrication systems. These new findings suggest the study of potential energy evolution is advantageous for understanding adhesive friction and infers the potential to leverage adhesion in 2D lubricant application through high conversion efficiency and out-of-phase oscillations between strain and cohesive energies.

Numerical and experimental 3-point bending quasi-static flexural behavior of single-strap joints joined using AF163-2K adhesive films

ABSTRACT This paper evaluated the mechanical characteristics of adhesive-single-bonded strap joints with varied numbers of adhesive layers subjected to flexural loads. Six samples were submitted to a 3-point bending test, three with the strap facing up and three with the strap facing down, and the failure behavior was analyzed. A 3-D finite element (FE) model was created in ABAQUS/Explicit. The adhesive layer (AF163-2K) failure was represented by cohesive zone components. It was discovered that the samples with the thickest adhesive layer obtained the highest load values. Furthermore, compared to samples with the strap facing down, those with the strap facing up demonstrated greater strength. Experiments were conducted to validate the constructed numerical model. Given that this type of configuration is one of the most commonly employed, especially in the repair of aeronautical structures, studying single-strap joints is deemed beneficial for designers.

Genomic and Pathologic Profiling of Very Well-Differentiated Gastric Adenocarcinoma of Intestinal Type: A Study With Emphasis on Diffuse-Type Transformation.

Very well-differentiated adenocarcinoma of intestinal type is a distinct subtype of gastric cancer characterized by anastomosing glands with a hand-in-hand pattern and low-grade cytologic atypia resembling intestinal metaplasia. This is a slow-growing neoplasm with an indolent clinical course; however, a subset demonstrates transformation into adenocarcinoma with higher-grade histology, typically diffuse-type carcinoma, and behaves aggressively. This study aimed to better characterize the genomic and pathologic features, with a focus on factors associated with diffuse-type transformation. A total of 58 cases with (n=31) and without (n=27) diffuse-type transformation were analyzed for molecular and pathologic features. First, comprehensive deep DNA sequencing was conducted in 18 cases (discovery cohort), followed by a digital droplet polymerase chain reaction of hot spot RHOA mutations in 40 cases (validation cohort). In total, RHOA mutations were the most common alteration (34%), followed by loss of ARID1A (12%), p53 alterations (10%), and CLDN18 :: ARHGAP26/6 fusions (3.4%). FGFR2 amplification was identified in an advanced case with a p53 alteration. Altered p53 expression was recognized only in higher-grade components and was significantly associated with advanced disease ( P =0.0015) and diffuse-type transformation ( P =0.026). A mixed mucin phenotype was also strongly correlated with advanced disease ( P <0.001) and diffuse-type transformation ( P <0.001). Decreased E-cadherin expression was frequently observed (74%) in poorly cohesive components. This study demonstrated that a subset of RHOA -mutant diffuse-type gastric cancers develops through the transformation of very well-differentiated adenocarcinoma of intestinal type. Our observations suggest a mixed mucin phenotype as a risk factor and alterations in p53 and E-cadherin as drivers of diffuse-type transformation.

Construction and Statistical Analysis of Discourse Cohesive Components in Modern Chinese

In discourse semantic analysis, the primary focus lies on cohesive elements that maintain discourse coherence. Additionally, attention is given to referring components and topic description structures that facilitate articulation. Various terms are used to refer to these cohesive elements, such as connecting components, logical connectives, relational words and cohesive components. However, there is a lack of unified terminology. The concept of cohesive components has been proposed before. In prior research, it primarily encompassed connectives, discourse markers and tone words, all of which contribute to discourse coherence. However, these definitions were relatively imprecise, and previous studies did not systematically categorize discourse cohesive components based on specific semantic functions. Consequently, they were inadequate for chapter-level semantic analysis. This paper extends the definition and scope of cohesive components based on existing research. It categorizes cohesive components according to both their formal characteristics and semantic functions. We extract cohesive components from the BLCU-CST tree bank, filter them based on specific scope and definition, and summarize a total of 247 logical connectives, 118 discourse connective markers and six types of numerical sequence connectives. In terms of semantic function, we analyze the distribution of 14 different logical-semantic relations that cohesive components indicate within discourse. This analysis not only enriches the understanding of discourse semantics for natural language comprehension but also offers valuable insights for linguistic ontology research.

Phacoemulsification with IOL implantation at a critical level of corneal endothelial cells

BACKGROUND: Cataract phacoemulsification is one of the most frequently performed surgical procedures, and a decrease in the corneal endothelial cell density (ECD) is the main postoperative complication leading to visual impairment. The average cell loss after phacoemulsification is 4.0112.94% within a year, and within 2 months 5.29.1%. The use of viscoelastics helps to reduce this loss, but it is impossible to completely prevent it.&#x0D; AIM: Сomparison of ECD in the pre- and postoperative period of phacoemulsification using viscoelastic of different percentages at a critical level of corneal endothelial cells.&#x0D; MATERIALS AND METHODS: The study included 60 eyes with emmetropic refraction: in the first group: 30 eyes with initial cataract and low ECD level (1694/1218 cells/mm2), an apyrogenic moderately cohesive viscoelastic 1.6% sodium hyaluronate solution (Kogevisk, Solopharm) was used, in the second group: 30 eyes with mature cataract and ECD level (1646/1183 cells/mm2) an apyrogenic, highly purified viscoelastic was used, consisting of medium-molecular fractions of chondroitin sodium sulfate 4% and sodium hyaluronate 3% (Adhevisk, Solopharm). Before surgery and a month after surgery, patients were tested for uncorrected visual acuity in the distance, ECD measurements, and intraocular pressure measurement.&#x0D; RESULTS: In phacoemulsification with IOL implantation, the use of viscoelastics of different percentages shows that the condition of the cornea remained stable a month after surgery. Postoperative ECD loss in all clinical cases, regardless of the stage of cataract, was less than 3%.&#x0D; CONCLUSIONS: Viscoelastics allow to solve the tasks set: in the case of cohesive maintaining the depth of the anterior chamber and the width of the pupil, adhesive protecting the corneal endothelium, good visualization. Rational consistent use of adhesive and cohesive components facilitates basic manipulations during phacoemulsification and IOL implantation. To do this, it is necessary to correctly use and select viscoelastic for a particular operation based on the number of endothelial cells.

PiouCrypt: Decentralized lattice-based method for visual symmetric cryptography

In recent years, establishing secure visual communications has turned into one of the essential problems for security engineers and researchers. However, only limited novel solutions are provided for image encryption, and limiting visual cryptography to only limited schemes can bring up negative consequences, especially with emerging quantum computational systems. This paper presents a novel algorithm for establishing secure private visual communication. The proposed method has a layered architecture with several cohesive components, and corresponded with an NP-hard problem, despite its symmetric structure. This two-step technique is not limited to gray-scale pictures, and furthermore, it is relatively secure from the theoretical dimension.

SoK: Run-time security for cloud microservices. Are we there yet?

The adoption of microservice architecture is rapidly growing, involving industries of every size. Their ability to scale and reconstitute complex functionalities into small, cohesive, and interconnected components (the microservices), and their limited use of isolation contribute to this success. Unfortunately but unsurprisingly, these very factors enlarge the attack surface and increase the security risks of today’s deployments. In this study, we performed a systematization of knowledge about the run-time security of microservices. Starting from a keyword search, we initially reviewed 807 papers available in digital libraries (e.g., Google Scholar and Scopus), which we filtered down to 48 by applying a number of selection criteria (e.g., the presence of a proof-of-concept implementation). We also considered over 30 industry tools that offer various security services for microservices. We categorized both papers and tools and highlighted areas where research is abundant, where it is lacking, and where it is misleading. We conclude that the run-time security of microservices is still in its infancy and we supplement our analyses with insights into addressing the key challenges.

Cohesive components in coal and their cohesive mechanism during pyrolysis

The cohesive components in coals and their detailed structure were investigated. The results show that the caking index of Linfen fat coal after extracting by benzene and tetrahydrofuran (THF) decreases from 89 to 43. Through analyzes of FT-IR and synchronous fluorescence spectrometry, anthanthrene is considered as the primary cohesive component to determine the cohesiveness of coal, and it is 42.4 wt% in the extract by THF from fat coal. Meanwhile, 1-naphthol, the secondary cohesive component to influence the cohesiveness of coal, is 22.8 wt% in the extract by benzene from fat coal. The cohesive phenomenon of coal has a positive correlation with the maximum aromaticity index (fa), and the cohesive phenomenon cannot be found during pyrolysis when the maximum fa of samples is smaller than 0.640, which are found from SEM images and XRD spectra of the carbonized samples. Moreover, the addition of anthanthrene makes Shenfu sub-bituminous coal produce cohesive phenomenon that coal particles connect together through the formation of a uniform surface. Based on these findings, a possible cohesive mechanism of coal was proposed.

The Clinicopathological Features of Mixed Carcinoma in 7,215 Patients with Gastric Cancer in a Tertiary Hospital in South Korea.

There are few reports regarding mixed carcinoma, defined as a mixture of glandular and poorly cohesive components, in patients with gastric cancer (GC). The aim of this study was to evaluate the proportion and characteristics of mixed carcinoma in GC patients. A total of 7,215 patients diagnosed with GC at Seoul National University Bundang Hospital were enrolled from March 2011 to February 2020. GC was divided into four groups (well-moderately differentiated GC, poorly differentiated GC, poorly cohesive carcinoma, and mixed carcinoma). The proportion of each GC type and the clinicopathological features were analyzed and divided into early GC and advanced GC. The proportion of mixed carcinoma was 10.9% (n=787). In early GC, submucosal invasion was the most common in poorly differentiated (53.7%), and mixed carcinoma ranked second (41.1%). Mixed carcinoma showed the highest proportion of lymph node metastasis in early GC (23.0%) and advanced GC (78.3%). In advanced GC, the rate of distant metastasis was 3.6% and 3.9% in well-moderately differentiated GC and mixed carcinoma, respectively, lower than that in poorly differentiated GC (6.4%) and poorly cohesive carcinoma (5.7%), without statistical significance. Mixed carcinoma was associated with lymph node metastasis compared to other histological GC subtypes. And it showed relatively common submucosal invasion in early GC, but the rates of venous invasion and distant metastasis were lower in advanced GC. Further research is needed to uncover the mechanism underlying these characteristics of mixed carcinoma (Trial registration number: NCT04973631).

Topographic thresholds for gully head formation in badlands

AbstractGully erosion is a particularly damaging process which is not yet sufficiently understood and parameterized. Gully head topographic threshold relative to Hortonian runoff have been studied in cropland, rangeland and forest. This study extends such modelling approach to badlands. Different badlands (eight sites) have been studied in the Mediterranean environment in Italy and Spain, characterized by diversified climatic, lithological, and geological settings under different anthropogenic conditioning. Many badlands have been characterized by their specific human history in addition to their geomorphological properties. Land use, as part of the human history, strongly affected many badland formation and development, through extremely impacting land exploitation (usually overgrazing). The effect of geological and geomorphological processes are usually particularly well visible. While the weakening effect of joints is confirmed, the different geological layer bedding orientation with respect to the slope aspect generates a different development of badland morphologies and different values of gully head thresholds values (as shown in two badlands sites on the same geological material and climate.The selection of Curve Number values, at the base of the introduction of land use into the gully head thresholds, has been more objectively defined in order to reduce arbitrariness in threshold application. The study additionally revises some of the physical basics behind the gully head threshold concept, requiring a description of the soil resistance in terms of frictional and cohesive components. This implies the explicit inclusion of rock fragment into the grain size distribution, which cannot be limited to fine grains. It results into an enriched threshold formulation that allows to describe the condition for gully head initiation and retreat as the result of the tradeoff between the frictional and cohesive components of the soil resistance forces. Eventually, the gully head threshold concept is confirmed and extended to include badlands.

Experimental evaluation of cohesive laws components of mixed-mode I + II fracture characterization of cortical bone

Mixed-mode I + II fracture characterization of cortical bone tissue is addressed in this work. The mixed-mode bending test was used to impose different mode ratios. An equivalent crack length data reduction method was considered to obtain the strain energy release rate components. Crack opening and shear displacements were measured by means of digital image correlation. These quantities were then integrated to propose a direct evaluation of cohesive laws. The components of the cohesive laws for each mixed-mode loading were obtained by the uncoupled and Högberg’s methods. The later provided consistent evolution of strain energy release rate and peak stresses components in function of mode-ratio, revealing its appropriateness regarding the fracture characterization of cortical bone under mixed-mode I + II loading.

Micro‐IDE: A tool platform for generating efficient deployment alternatives based on microservices

AbstractMicroservice architecture (MSA) is a paradigm to design and develop scalable distributed applications using loosely coupled, highly cohesive components that can be deployed independently. The applications that realize the MSA may contain thousands of services that together form the overall system. Microservices interact with each other by producing and consuming data. Deploying frequently communicating services to the same physical resource would reduce network utilization, which is vital for reducing costs and improving scalability. Since the physical resources have limited capacity, it is not always possible to deploy communicating services to the same resource. Therefore, automated efficient deployment alternatives need to be generated for MSA in the design phase. To address this problem, we proposed an algorithmic approach to generate efficient microservice deployment configurations to available cloud resources in our previous study. In this study, a tool (Micro‐IDE) has been proposed to realize and evaluate this approach. The Micro‐IDE tool has been validated using a case study inspired by the Spotify application.

Formulation of Biopharmaceutical Dry Powder Inhaler Using the Void Forming Index (VFI) to Detect and Avoid Powder Caking in Dry Powder Inhaler Formulations.

It is mandatory to detect the powder cohesiveness of biopharmaceutical dry powder inhaler (Bio-DPI) formulations and their effect on their performance. Normally, Bio-DPI formulations consist of highly cohesive components with higher drug amounts than small molecules. Herein, a formulation study of a high-drug-ratio Bio-DPI was performed, detecting the risk of powder caking in DPI formulations. The Bio-DPI formulation was manufactured via the spray-dry method followed by mixing with excipients. Powder caking was detected through the void forming index (VFI), which was calculated using pressure drop measured by inverse gas chromatography (iGC). Since VFI can be used to evaluate the structural changes induced by powder caking over time with less than 1 g of sample, VFI is considered suitalbe to apply for DPI formulation screening. The risk of powder caking was detected in spray dryed particles at more than 45% relative humidity (RH) humidity condition, mannitol (as a carrier particle) and magnesium stearate (as a lubricant) were added to the formulations. With formulation screening, addition of more than 40% of mannitol was suggested to reduce the risk of powder caking. Selected DPI formulation remained higher emitted ratio (95.6%), than spray dried particle (52.5%) at 25 °C 65% RH condition for 1-month storage. In conclusion, VFI measurement is useful for selecting the DPI formulation by mitigating powder caking risk with limited samples.

Determination of Adhesive and Cohesive Strength in Metal Coatings Deposited by Hypersonic Metallization

. It is known that at present, methods of thermal spraying are widely used to restore and strengthen various worn-out machine parts. As a rule, metal coatings applied by thermal spraying have lower strength characteristics than solid materials. It is believed that the strength of coatings is proportional to their adhesive and cohesive strength. The value of adhesive and cohesive strength depends on various factors, including the nature of the materials and the technology of coating. An important factor characterizing the possibility of using metal coatings in various industries is the strength of adhesion of coatings to the base metal. The paper presents the determination of the adhesive and cohesive strength of coatings from different materials, applied by the method of hypersonic metallization. The results of testing the strength of metal coatings made of ER316LSi-grade wire, nichrome (Cr20Ni80) and molybdenum wire are given in the paper. Based on the results of metallographic studies, the proportion of the participation of cohesive and adhesive components in the strength of coatings has been determined, and some features of coating destruction have been described. It has been found that the participation of the cohesive and adhesive components of the coating strength differs depending on the material used. The cohesive component prevails in the strength of coatings made of high-alloy wire of the ER316LSi-grade, at which destruction mainly occurs along the coating-base boundary. For nichrome coatings and especially for coatings made of molybdenum, the cohesive component is predominant, in which the destruction of the coating occurs not along the coating-base boundary, but between the coating layers.

Direct Evaluation of Mixed Mode I+II Cohesive Laws of Wood by Coupling MMB Test with DIC.

Governing cohesive laws in mixed mode I+II loading of Pinus pinaster Ait. are directly identified by coupling the mixed mode bending test with full-field displacements measured at the crack tip by Digital Image Correlation (DIC). A sequence of mixed mode ratios is studied. The proposed data reduction relies on: (i) the compliance-based beam method for evaluating strain energy release rate; (ii) the local measurement of displacements to compute the crack tip opening displacement; and (iii) an uncoupled approach for the reconstruction of the cohesive laws and its mode I and mode II components. Quantitative parameters are extracted from the set of cohesive laws components in function of the global phase angle. Linear functions were adjusted to reflect the observed trends and the pure modes (I and II) fracture parameters were estimated by extrapolation. Results show that the obtained assessments agree with previous experimental measurements addressing pure modes (I and II) loadings on this wood species, which reveals the appropriateness of the proposed methodology to evaluate the cohesive law under mixed mode loading and its components.

Determining Interface Fracture Toughness in Multi Layered Environmental Barrier Coatings with Laser Textured Silicon Bond Coat

In the high temperature combustion atmosphere inside of aircraft turbines, the currently used ceramic matrix composites require a protective environmental barrier coating (EBC) to mitigate corrosion of the turbine parts. Besides thermomechanical and thermochemical properties like matching thermal expansion coefficient (CTE) and a high resistance against corrosive media, mechanical properties like a high adhesion strength are also necessary for a long lifetime of the EBC. In the present work, the adhesion between an air plasma sprayed silicon bond coat and a vacuum plasma sprayed ytterbium disilicate topcoat was aimed to be enhanced by a laser surface structuring of the Si bond coat. An increase in interface toughness was assumed, since the introduction of structures would lead to an increased mechanical interlocking at the rougher bond coat interface. The interface toughness was measured by a new testing method, which allows the testing of specific interfaces. The results demonstrate a clear increase of the toughness from an original bond coat/topcoat interface (8.6 J/m2) compared to a laser structured interface (14.7 J/m2). Observations in the crack propagation indicates that the laser structuring may have led to a strengthening of the upper bond coat area by sintering. Furthermore, in addition to cohesive failure components, adhesive components can also be observed, which could have influenced the determined toughness.

Исследование пигментов и связующих красочных слоев росписей храма X–XIII вв. на плато Эски-Кермен

In 2018–2019, the excavations of an aisleless church dated from the tenth to thirteenth centuries and located in quarter II on the territory of a provincial Byzantine town atop of the plateau of Eski-Kermen discovered fragments of wall-plaster with polychrome painting. There are several shades of green, two shades of red, white (beige), yellow (ochre), and grey-brown colours. This paper presents the results of studies of the colour layer, determines pigments and cohesive colour components, and uncovers the features of the painting technique applied to the walls of the church. Four groups of samples were selected for the study featuring: 1 – white, 2 – yellow, 3 – red, and 4 – green colours. The elemental composition of the colour layer was studied by scanning electron microscopy combined with energy-dispersive X-ray microanalysis (SEM/EDX). The phase constitution of the samples was investigated by X-ray powder diffraction (XRD) method with the use of diffractometers operated in a transmission mode at the Kurchatov synchrotron radiation source. The chemical composition of colour layers was studied by infrared spectroscopy, and the study of cohesive colour materials was carried out by gas chromatography with mass spectrometry (GC/MS). The elemental composition and phase constitution of the white colour indicated the use of lime whitewash. Yellow ochre (goethite) was used as yellow colour. Red colour features the presence of hematite typical for the group of pigments united under the name of red soils. However, the discovery of 1% goethite typical for yellow ochres in the phase constitution of one sample allows the possibility that burnt yellow ochre was used as a red pigment. The green colour was green soil (glauconite and celadonite). It should be noted that none of the examined samples of red pigment contained traces of vermilion, which occurred in ancient paintings in the Crimea and was typical for Byzantine wall-paintings. In all the samples of pigments contained a significant degree of calcite (36-98%), possibly due to the presence of particles of undercolour in the measured samples of wall paintings, or diluting the pigment with lime water for the making of wall-painting featuring fresco technique. The use of the latter technique is also indicated by the presence of white lime colour. The traces of cohesive component in the form of fish glue and protein products from chicken eggs found in the red and green paint samples also suggests the use of the dry painting technique. Therefore, there are reasons to suppose that the painting of the quarter church of Eski-Kermen used two techniques, fresco and dry plaster paintings.

An analytical model for strength of jointed rock masses

An analytical model of rock mass with non-persistent joints is utilized to develop linear and nonlinear failure criteria based on intact rock strength, joint shear strength and joint persistence. The analytical model matches the solutions for the strength of fracture-free and fully jointed rocks and provides a reasonable transition of strength for rocks with non-persistent joints. Consistent with empirical evidence, the model predicts that increasing joint intensity and decreasing joint shear strength cause a reduction in the cohesive and frictional components of rock mass strength. Joint persistence in the analytical model has not only a physical definition as the normalized jointed area, but also a mechanical interpretation as the normalized reduction in strength due to the presence of joints. The relationship between the analytical model and the empirical Hoek-Brown failure criterion with Geological Strength Index (GSI) is explored. The analytical model of rock mass is utilized to develop and calibrate a quantitative GSI chart. The analytical model is validated using the results of comprehensive tests on undisturbed samples of naturally jointed Panguna andesite and thermally granulated Carrara marble. Practical application of the analytical model is illustrated by numerical back analysis of displacements around the Nathpa Jhakri powerhouse cavern.

PCI-PSO: Preference-Based Component Identification Using Particle Swarm Optimization

Abstract Nowadays, component identification is one of the main challenges of software analysis and design. The component identification process aims at clustering classes into components and subcomponents. There are a number of methods to identify components in the literature; however, most of them cannot be customized to software architect’s preferences. To address this limitation, in this paper, we propose a preference-based method by the name of preference-based component identification using particle swarm optimization (PCI-PSO) to identify logical components. PCI-PSO provides a novel method to handle the software architect’s preferences using an interactive (i.e. human in the loop) search. PCI-PSO employs a customized PSO to automatically classify classes into suitable logical components and avoid the problem of identifying the proper number of components. We evaluated the effectiveness of PCI-PSO with four real-world cases. Results revealed that PCI-PSO has an ability to identify more cohesive and independent components with respect to the software architect’s preferences in comparison to the existing component identification methods.

Bond behavior of NiTiNb SMA wires embedded in CFRP composites

This article summarizes the details of an experimental and analytical program that was conducted to study the bond behavior between nickel‐titanium‐niobium shape memory alloy wires and fiber reinforced polymer composites. Understanding this bond behavior will facilitate the design of composite systems that are fabricated using both materials and which would exhibit unique properties that cannot be achieved using either material separately. A total of nine pull‐out specimens were fabricated and tested. A digital image correlation (DIC) noncontact measurement system was used to identify the onset and propagation of the debonding. The experimental results indicated that the interfacial bond transfer consists of two components: cohesion (before the onset of debonding) and friction (after the onset of debonding). A 3‐D nonlinear finite element analysis (FEA) was conducted to investigate the debonding mechanism of the pull‐out specimens. A trilinear cohesive zone model was used to model the interface taking into account the cohesive and friction components of the stress transfer at the interface. The debonding mechanism predicted by the FEA matches the experimental observations that were obtained using conventional instruments and the DIC system, well. POLYM. COMPOS., 39:3780–3791, 2018. © 2017 Society of Plastics Engineers