Texture Dimensions Research Articles

Application of Texture and Fractal Dimension Analysis to Estimate Effectiveness of Oral Leukoplakia Treatment Using an Er:YAG Laser-A Prospective Study.

Background: Oral leukoplakia (OL) is a potential neoplasmic lesion. The aim of this study was to apply texture analysis (TA) and fractal dimension analysis (FDA) to estimate the effectiveness of OL treatment using an Er:YAG laser. Methods: Eighteen patients with 32 lesions were treated. Laser procedures were conducted using the LiteTouch™ Er:YAG Dental Laser. The diameter of the operational tip was 1.3 mm, the power was 50 mJ, the frequency was 50 Hz, and the wavelength was 2940 nm. TA was based on long and short-run emphasis inverse moments, difference entropy, inverse difference moment, and wavelet decomposition for two-dimensional photography. FDA was measured using the box-counting method. Results: Total response was achieved in 50% of lesions, partial response was observed in 47%, and 3% of lesions did not respond to treatment. Recurrence occurred in 34% of lesions. TA features indicated pathological images depicting leukoplakia and complete reconstruction of the correct mucosal image after laser ablation. The discrete wavelet transformation feature detects much larger structures than the properties derived from the run-length matrix and co-occurrence matrix. Conclusions: The Er:YAG laser is an effective treatment method in cases of oral leukoplakia. Leukoplakia treatment by Er:YAG laser is an effective modality, as revealed by the oral mucosa microstructure. TA and FDA are promising methods to estimate the effectiveness of OL treatment.

Myocardial extracellular volume fraction radiomics analysis for differentiation of reversible versus irreversible myocardial damage and prediction of left ventricular adverse remodeling after ST-elevation myocardial infarction.

Our study sought to explore the prognostic value of radiomic TA (texture analysis) on quantitative ECV (extracellular volume) fraction mapping to differentiate between reversible and irreversible myocardial damage and to predict left ventricular adverse remodeling in patients with reperfused STEMI (ST-elevation myocardial infarction). This observational prospective cohort study identified 70 patients (62 ± 9years, 62 men [85.70%]) with STEMI for TA who consecutively performed native and contrast T1 mapping. Texture features were extracted from each stack of ECV mapping based on ROI (region of interest) analysis. After texture feature selection and dimension reduction, five selected texture features were found to be statistically significant for differentiating the extent of myocardial injury. ROC (receiver operating characteristic) curve analysis for the differentiation of unsalvageable infarction and salvageable myocardium demonstrated a significantly higher AUC (area under the curve) (0.91 [95% CI, 0.86-0.96], p < 0.0001) for horizontal fraction than other texture features (p < 0.05). LVAR (left ventricular adverse remodeling) was predicted by those selected features. The differences in qualitative and quantitative baseline parameters and horizontal fractions were significant between the patients with and without LVAR. LGE (late gadolinium enhancement) and horizontal fraction features of infarcted myocardium in acute STEMI were the only two parameters selected in forming the optimal overall multivariable model for LVAR at 6months. Radiomic analysis of ECV could discriminate reversible from irreversible myocardial injury after STEMI. LGE as well as radiomics TA (texture analysis) of ECV may provide an alternative to predict LVAR and functional recovery. • ECV quantification was able to differentiate between infarcted myocardium and non-infarcted myocardium. • Radiomics analysis of ECV could discriminate reversible from irreversible myocardial injury. • Radiomics TA analysis shows a promising similarity with LGE findings which could aid the prognosis of myocardial infarction patients.

Effect of Scale and Sequence of Surface Textures on the Anti-adhesive Wear Performance of PVD Coated Tool in Dry Machining SLM-Produced Stainless Steel

During the dry post-machining processing of selective laser melting (SLM)-produced stainless steel with TiAlN coated tool, the elements of stainless steel chips can diffuse and adhere into the coated tool surface, causing serious adhesive wear. In this study, to inhibit the adhesion problem at the tool-chip interface, surface textures with different scales (micro-, nano- and micro/nano-textures) are produced on tool rake face by laser processing before and after physical vapor deposition (PVD) TiAlN coatings deposition. To investigate the cutting performance of these developed coated tools, dry machining tests of the SLM-produced stainless steel are carried out. And, the mechanical properties of textured TiAlN coatings such as the hardness, elastic modulus and critical load are also studied to explain the results from the machining tests. It can be found that the anti-adhesive wear performance of TiAlN coated tool is improved by laser surface texturing. The texture dimension significantly affects the mechanical properties and dry cutting performance of the TiAlN coated tool, and the micro/nano-textures are found to be optimum. Meanwhile, the sequence of surface textures also has an effect on the wear performance of the developed TiAlN coated tools. In the experiment, laser surface texturing before coatings is effective in acting as a barrier against flaking of the TiAlN film, providing a higher active surface for the subsequent TiAlN coatings and presenting a higher compressive residual stress. Thus, the developed cutting tool which is textured before TiAlN coatings deposition presents a milder wear compared to the developed one which is textured after TiAlN coatings deposition.

Deposition of biphasic calcium phosphate film on laser surface textured Ti–6Al–4V and its effect on different biological properties for orthopedic applications

Abstract The present study reports laser surface texturing (LST) of Ti–6Al–4V using a Nd-YAG laser with a particular set of parameters and three different overlapping factors (OF): 0%, 25% and 50%. Biphasic calcium phosphate (BCP) film was deposited on bare as well as textured Ti–6Al–4V specimens by using radio frequency (RF) sputtering. The simultaneous effect of texturing as well as BCP coating on different physical and biological properties was investigated. The study revealed that the surface wettability of bare Ti–6Al–4V enhanced after laser texturing (as contact angle reduced from 89° to 71°-77°). It was further improved upon BCP deposition to make the Ti–6Al–4V superhydrophilic (contact angle ≈ 17°-21°). It was also observed that the surface roughness of bare Ti–6Al–4V significantly increased from Ra ≈ 94 nm to Ra ≈ 0.98–1.84 μm for different micro-dimpled texture substrates. The dimensions of micro-dimpled texture did not change after BCP deposition; however, a non-uniform film is deposited with increase in surface roughness. Protein adsorption was found as a function of surface hydrophobicity, which increased from 5.3 to 7.11 μg/cm2 with the rise in hydrophobicity of modified surfaces. Compared to bare Ti–6Al–4V and BCP deposited bare-Ti-6Al–4V surfaces, the BCP deposited textured surfaces exhibit higher number of well spread MG63 osteoblast cells. For the same surface chemistry, increase in surface area (roughness) improves cellular behavior. With texturing of the substrate, the cell adhered percentage and average cell area improved significantly and BCP-(50% OF)–Ti–6Al–4V was found to have the maximum cell spreading and proliferation. Overall, these findings revealed that a micro-dimpled textured surface followed by BCP film deposition strategy improved the physio-chemical properties of surfaces such as surface roughness and wettability. This in turn enhanced the bioactivity, cell adhesion and proliferation of bone cells (MG63) on modified Ti–6Al–4V surfaces and based on the results we envisage that can be potentially used for orthopedic and dental applications.

The Development of a BMI-Guided Shape Morphing Technique and the Effects of an Individualized Figure Rating Scale on Self-Perception of Body Size

The creation of personalized avatars that may be morphed to simulate realistic changes in body size is useful when studying self-perception of body size. One drawback is that these methods are resource intensive compared to rating scales that rely upon generalized drawings. Little is known about how body perception ratings compare across different methods, particularly across differing levels of personalized detail in visualizations. This knowledge is essential to inform future decisions about the appropriate tradeoff between personalized realism and resource availability. The current study aimed to determine the impact of varying degrees of personalized realism on self-perception of body size. We explored this topic in young adult women, using a generalized line drawing scale, as well as several types of personalized avatars, including 3D textured images presented in immersive virtual reality (VR). Body perception ratings using generalized line drawings were often higher than responses using individualized visualization methods. While the personalized details seemed to help with identification, there were few differences among the three conditions containing different amounts of individualized realism (e.g., photo-realistic texture). These results suggest that using scales based on personalized texture and limb dimensions are beneficial, although presentation in immersive VR may not be essential.

Combined effects of tool surface texturing, cutting parameters and minimum quantity lubrication (MQL) pressure on micro-grinding of BK7 glass

Capability of sintered micro-grinding tool is limited by low chip space, ineffective lubrication access and premature loading which results in high cutting forces and brittle mode fractures on the work surfaces. Usage of textured tool is one of the methods to avoid aforesaid phenomena and to achieve high cutting performance. On machine fabrication of textured micro-tools and correlating their cutting mechanism with texture dimension are some of the primary challenges. A new electric discharge texturing method for on-machine fabrication of textured tools is devised and the tools with optimum intermittent ratio but varying texture dimensions are fabricated. Micro-grinding experiments are carried out on BK7 glass to establish the correlation between cutting performance with texture dimension, cutting parameters and MQL (minimum quantity lubrication) pressure. It is concluded that tool with small size and large number of texture units reduced the cutting forces, surface roughness and edge chipping by 25–35 % of those obtained by a tool without texture at depth of cut 10 μm and feed rate 5 mm/min. The amount of reductions of these two process parameters even reached to 50–60 % at high depth of cut 40 μm and feed rate 11 mm/min. The reduction in output parameters is supported by the observation of effective migration of chips in the passive areas. It is also established in this study that MQL spray droplet size should be very close to the texture dimension to ensure maximum cutting fluid access in the machining zone. Analytical derivation of penetration depth for textured tools indicated delayed chances of ductile to brittle transition when the tools with small size texture units are used in place of the tools with large size texture units.

The quality evaluation method of tilapia fillets stored at 3 and −2°C based on fractal dimension changes

AbstractIn this work, a correlation model of tilapia fillets quality evaluation was established by principal component analysis (PCA) based on fractal dimension change. The tilapia fillets were stored at 3 and −2°C, respectively, and the pH, color, electrical conductivity (EC), total volatile base nitrogen (TVB‐N), texture, and fractal dimension were periodically measured. A major component was extracted and it explained 82.726% of the total variance. Then the comprehensive quality score was calculated during the storage of the fillets. Three function correlation models including linear function, logarithmic function, and quadratic function were obtained by establishing the relationship between the comprehensive quality score of fillets and the fractal dimension. The determination coefficient R2 of quadratic function correlation model reached 0.841 and 0.962 under 3 and −2°C, respectively. This result indicated that the quality evaluation was accurate under low‐temperature storage conditions by quadratic function correlation model based on the change of fractal dimension.Practical applicationsThe conventional quality evaluation methods of tilapia fillets are time‐consuming and cumbersome. This work used PCA to integrate many tilapia fillets quality indicators into a comprehensive quality indicator. Then a correlation function model was established between comprehensive quality indicator and fractal dimension. The quality of tilapia fillets would be evaluated by the change of fractal dimension in profile. The result showed that this method was simple and fast, and laid a foundation for the application of fractal dimension in tilapia processing and transportation.

RESEARCH ON 3D BUILDING VISUALIZATION BASED ON TEXTURE SIMPLIFICATION AND FRACTAL COMPRESSION

Abstract. There are some problems in the visualization of 3D model of buildings at present, such as redundant texture data and large memory occupation of loading texture data, which pose challenges to the smooth loading of 3D building visualization. In this paper, we propose a method which using fractal quadtrees to simplify texture data and compress management. Firstly, this method uses the fractal self-similarity and the feature that the same texture has the same fractal dimension to screen all the textures, when the fractal dimension of multiple textures is within the threshold range. Radon transform will be performed on these textures to calculate their standard deviation and further simplify the texture. Secondly, we use fractal texture compression to create a multi-resolution texture data structure with quadtree structure, so that the building 3D model can achieve dynamic visualization of different scales. Finally, the parallel texture mapping of all faces of the 3D model of the building is implemented according to the texture calling rules. Experimental results demonstrate that the texture is managed by the method proposed in this paper, which shortens the loading time of texture and reduces the memory occupation by about 48.92%. Therefore, the method of texture simplification and compression proposed in this paper has a significant effect in the process of building 3D model visualization.

FRACTAL TEXTURE AND STRUCTURE OF CENTRAL PLACE SYSTEMS

The boundaries of central place models proved to be fractal lines, which compose fractal texture of central place networks. However, the fractal texture cannot be verified by empirical analyses based on observed data. On the other hand, fractal structure of central place systems in the real world can be empirically confirmed by positive studies, but there are no corresponding models. The spatial structure of classic central place models bears Euclidean dimension [Formula: see text] rather than fractal dimensions [Formula: see text]. This paper is devoted to deriving structural fractals of central place models from the textural fractals. The method is theoretical deduction based on the dimension rules of fractal sets. The main results and findings are as follows. First, the central place fractals were formulated by the [Formula: see text] numbers and [Formula: see text] numbers. Second, three structural fractal models were constructed for central place systems according to the corresponding fractal dimensions. Third, the classic central place models proved to comprise Koch snowflake curve, Sierpinski space filling curve, and Gosper snowflake curve. Moreover, the traffic principle plays a leading role in urban and rural settlements evolution. A conclusion was reached that the textural fractal dimensions of central place models can be converted into the structural fractal dimensions and vice versa, and the structural dimensions can be directly used to appraise human settlement distributions in reality. Thus, the textural fractals can be indirectly employed to characterize the systems of human settlements.

Towards Multisensory Perception: Modeling and Rendering Sounds of Tool-Surface Interactions.

Touch-produced sounds in tool-surface interactions convey rich information about textured surface properties and provide direct feedback about how users interact with the surface. This article presents a statistical learning-based approach for modeling and rendering touch-produced sounds in real time. We apply a data-driven modeling method, which recreates highly realistic sounds using audio signals recorded from unconstrained tool-surface interactions. The recorded sound is segmented, and each segment is labeled with the average velocity during that time. We model each segment with wavelet tree models using a moving window approach. Each window is analyzed by fast wavelet transform and is then broken down into a tree structure. During rendering, we use the user's current velocity to select tree models and synthesize new sounds by breadth-first search and inverse wavelet transform. We conducted a user study to evaluate the realism of our virtual sounds and their effect on human's perception of the texture dimensions in the presence of simultaneous real haptic cues. The results showed that in the presence of haptic cues, the virtual sound can more completely capture the texture's roughness and hardness than haptic cues alone. However, the perception on slipperiness depended mainly on touch.

Food-texture dimensions expressed by Japanese onomatopoeic words.

This study examined perceptual dimensions of food texture using Japanese onomatopoeic words. Photographs of 56 foods were presented to the participants, and they reported onomatopoeic (mimetic) words suitable for the texture of the foods. The participants' responses were collated into a contingency table of photographs by onomatopoeic words. Correspondence analysis was applied to the table, and 15 dimensions were extracted. The biplot of the configurations was rotated by the technique of sparse coding. The obtained dimensions were smoothness/sounds in slurping noodles; adhesiveness; crumbliness/dryness/fluffiness of breads; popping/juiciness of spherical‐shaped foods; soft elasticity/smoothness of gel, wateriness/creaminess; bendability of sticky foods; crispness/crunchiness of snacks; crispness of fruits; elasticity; crunchiness of vegetables; breakability of rod‐like foods; sizzle (high temperature and oiliness); and two dimensions specifically expressing textures of lemon and pickled plum. These are considered to be basic food‐texture dimensions expressed by Japanese onomatopoeic words.

Stiffness and Strength Estimation of Damaged Unreinforced Masonry Walls Using Crack Pattern

ABSTRACT After an earthquake, the residual stiffness and strength of structural elements are typically estimated based on a qualitative visual inspection of cracks that is prone to error. In this paper a new approach is proposed to automatically estimate the updated stiffness and strength of damaged unreinforced masonry walls by characterization of crack patterns by a mathematical index. It is shown that structural and textural fractal dimensions of a crack pattern reflect the extent of cracking and the type of cracking or crushing, i.e., whether the cracks pass through joints or whether bricks have been damaged and crushed. Using results of six quasi-static cyclic tests on unreinforced brick masonry walls with different failure modes at various drift ratios, it is shown that the structural and textural fractal dimensions of the crack patterns are an accurate predictor of the stiffness and strength degradation. This procedure seems therefore a promising approach for replacing the traditional assessment methods that are based on visual inspection and engineering judgment by an analytical procedure based on image processing that can eventually be completely automated.

Predictive Modelling of Benign and Malignant Tumors Using Binary Logistic, Support Vector Machine and Extreme Gradient Boosting Models

Breast cancer is the leading type of cancer among women worldwide, with about 2 million new cases and 627,000 deaths every year. The breast tumors can be malignant or benign. Medical screening can be used to detect the type of a diagnosed tumor. Alternatively, predictive modelling can also be used to predict whether a tumor is malignant or benign. However, the accuracy of the prediction algorithms is important since any incidence of false negatives may have dire consequence since a person cannot be put under medication, which can lead to death. Moreover, cases of false positives may subject an individual to unnecessary stress and medication. Therefore, this study sought to develop and validate a new predictive model based on binary logistic, support vector machine and extreme gradient boosting models in order to improve the prediction accuracy of the cancer tumors. This study used the Breast Cancer Wilcosin data set available on Kaggle. The dependent variable was whether a tumor is malignant or benign. The regressors were the tumor features such as radius, texture, area, perimeter, smoothness, compactness, concavity, concave points, symmetry and fractional dimension of the tumor. Data analysis was done using the R-statistical software and it involved, generation of descriptive statistics, data reduction, feature selection and model fitting. Before model fitting was done, the reduced data was split into the train set and the validation set. The results showed that the binary logistic, support vector machine and extreme gradient boosting models had predictive accuracies of 96.97%, 98.01% and 97.73%. This showed an improvement compared to already existing models. The results of this study showed that support vector machine and extreme gradient boosting have better prediction power for cancer tumors compared to binary logistic. This study recommends the use of support vector machine and extreme gradient boosting in cancer tumor prediction and also recommends further investigations for other algorithms that can improve prediction.

Picosecond laser texturing on titanium alloy for biomedical implants in cell proliferation and vascularization.

Introducing specific textures to titanium alloy implant surface is helpful to modify the surface properties of materials. In this article, biomedical TC4 (Ti-6Al-4V) alloy was textured by a 10-ps infrared laser. Laser parameters that directly affected the detailed dimension of textures and its characteristics were optimized within laser power, defocusing amount, and scanning parameters via response surface methodology. These textures consisted of groove array about 30-90 μm in depth and 100 μm in width were prepared and their surface property (including surface morphology, element composition, wetting behavior, and biocompatibility) was analyzed. Surface characteristic analysis indicated that picosecond laser texturing improved surface properties and biocompatibility mainly by altering the microstructure and morphology of materials. In addition, laser textured groove array promoted contact area and hydrophobicity of material surface. Cell culture experiments and animal studies showed that titanium alloy implants with 30- and 60-μm-deep groove arrays on the surface-enhanced cell proliferation and adhesion. Meanwhile, compared to the polished samples, these groove arrays promoted the growth of new blood vessels and enhanced the combination of blood vessel and implants in vivo. That is, the deeper groove array was, and the better vascularizing effect the blood vessel exhibited.

Production and Tribological Characterization of Tailored Laser-Induced Surface 3D Microtextures

The aim of the present study was firstly to determine the manufacturing feasibility of a specific surface 3D-microtexturing on steel through an ultra-short pulsed laser, and secondly to investigate the tribological properties under 2 different lubrication conditions: oil-lubricated and antifriction coated. The selected 3D-microtexture consisted of 2 different levels of quadratic micropillars having side dimensions of approximately 45 µm, heights of about 35 µm and periods of 80 µm. It was shown that the production of specific 3D-microtextures on steel substrates using an ultra-short pulsed laser was feasible, and that the reproducibility of the texture dimensions over the entire textured region was extremely good. Frictional investigations have shown that, in comparison to the benchmark (untextured samples), the 3D-microtextured samples do not induce any significant improvements in the coefficient of friction (COF) under oil-lubricated conditions, but that under antifriction coated conditions, significant improvements in the friction coefficients may be achieved. Wear-based tribological tests have shown that the antifriction coating on benchmark samples was completely depleted, which greatly influenced their friction and wear behavior, since steel-steel contact occurred during testing. For the 3D-microtexture, the antifriction coating was also partially depleted; however, it accumulated itself in the microtexture which acted as a potential lubricant reservoir.

Numerical and experimental studies on the grinding of cemented carbide with textured monolayer diamond wheels

Textured grinding wheels could provide more excellent grinding performances than conventional grinding wheels, which have been experimentally confirmed. However, for lack of in-depth understandings of the grains-workpiece micro contact and interactions, experimental methods can only obtain the macro grinding performances, and the key issues on textured grinding wheels cannot be experimentally explained. In this paper, the combination method of numerical analysis and experiment is proposed. The experiments are conducted to evaluate the machining performances of grinding wheels from a macro level. Meanwhile, numerical methods are used to analyze the distribution characteristics of undeformed chip thickness in micro cutting process. The effects of material removal rate, texture dimension (TD) and radial dressing of grinding wheels on the distribution characteristics of undeformed chip thickness are revealed. The strong correlations between the macro grinding performances and the distribution characteristics of undeformed chip thickness are proved, and what kind of distribution characteristics are beneficial to good grinding results can be discerned, which provides a theoretical basis for tool optimization. Then, optimization strategy and steps of grinding performances are proposed. A conventional grinding wheel with same geometric parameters and grain size is used as reference grinding wheel, and the distribution of undeformed chip thickness generated in stable wear stage by the reference grinding wheel is taken as optimization starting point. After optimization, a desired distribution of undeformed chip thickness can be obtained. Finally, grinding experiments are conducted to confirm the optimization effects. In this way, using the distribution characteristics of undeformed chip thickness as a pointer, the deeper understanding of key issues on textured grinding wheel will be reached.

Neural Coding for Shape and Texture in Macaque Area V4.

The distinct visual sensations of shape and texture have been studied separately in cortex; therefore, it remains unknown whether separate neuronal populations encode each of these properties or one population carries a joint encoding. We directly compared shape and texture selectivity of individual V4 neurons in awake macaques (1 male, 1 female) and found that V4 neurons lie along a continuum from strong tuning for boundary curvature of shapes to strong tuning for perceptual dimensions of texture. Among neurons tuned to both attributes, tuning for shape and texture were largely separable, with the latter delayed by ∼30 ms. We also found that shape stimuli typically evoked stronger, more selective responses than did texture patches, regardless of whether the latter were contained within or extended beyond the receptive field. These results suggest that there are separate specializations in mid-level cortical processing for visual attributes of shape and texture.SIGNIFICANCE STATEMENT Object recognition depends on our ability to see both the shape of the boundaries of objects and properties of their surfaces. However, neuroscientists have never before examined how shape and texture are linked together in mid-level visual cortex. In this study, we used systematically designed sets of simple shapes and texture patches to probe the responses of individual neurons in the primate visual cortex. Our results provide the first evidence that some cortical neurons specialize in processing shape whereas others specialize in processing textures. Most neurons lie between the ends of this continuum, and in these neurons we find that shape and texture encoding are largely independent.

The Development and Assessment of Crayons that Produce Textured Lines for Individuals Who Are Visually Impaired

Introduction: This article describes the development and initial assessment of a set of tactile crayons that can produce different textured lines and areas on standard paper. Method: An assessment of the need for tactile crayons was performed through the use of surveys and focus groups from which a set of six tactile crayons was developed. Development was focused on being able to differentiate the crayons along the texture dimensions of sticky or slippery, rough or smooth, and hard or soft in informal dimensional analysis. Preliminary discrimination testing was performed to determine the viability of the six selected crayons. The main assessment determined whether individuals were able to identify each of the crayons by number from feeling scribbles on paper. Results: User needs assessment showed that many practitioners felt the development of tactile crayons would aid in teaching and fill a needs gap. The participants were able to discriminate the six crayons with a mean accuracy (standard error) of 77% (4%), and of those six, they could identify the four most easily discriminable with 86% (3%) accuracy. Discussion: Many families and teachers showed interest in the potential of tactile crayons as a learning tool. Four of the six tactile crayons were both highly discriminable and identifiable by adults who are visually impaired. This finding shows promise for discriminability and identifiability of these crayons by children who are visually impaired and their potential as a learning tool in both formal and informal learning environments. Implications for practitioners: The use of the developed tactile crayons has the potential to aid childhood development and student learning. In addition, the use of the crayons by teachers could help reduce the time needed to produce tactile diagrams.

Differences in Chromatin Texture and Nuclear Fractal Dimension Between Hashimoto's and Lymphocytic Thyroiditis Lymphocytes.

Previous evidence suggested that lymphocytic thyroiditis (LT) was a variant of Hashimoto's thyroiditis (HT), thus the aim of the current study is to quantify structural changes in histological specimens taken from HT and LT patients. A total of 600 images containing a single lymphocyte nucleus (300 nuclei per group) were obtained from 20 patients with HT and LT. In order to quantify changes in the nuclear architecture of investigated lymphocytes, the fractal dimension (FD) and some gray-level co-occurrence matrix texture parameters (angular second moment, inverse difference moment, contrast, entropy, and correlation) were calculated for each nucleus. A statistically significant difference in the FD of the "binary-outlined" nucleus and that of the corresponding "black-and-white" nucleus was detected between HT and LT lymphocyte nuclei. In addition, there was also a statistically significant difference in contrast and correlation between HT and LT lymphocyte nuclei. In conclusion, the results of this study suggested that there was a difference in structural complexity between investigated lymphocyte nuclei; additionally, LT lymphocytes possessed probably more complex texture and larger variations as well as more asymmetrical nuclei compared with HT lymphocytes. Accordingly, these findings indicate that LT is probably not a variant of HT; however, more complex studies are necessary to estimate differences between these types of thyroiditis.

On-machine texturing of PCD micro-tools for dry micro-slot grinding of BK7 glass

While using diamond micro-tools for micro-grinding, tool re-clamping errors and low chip removal space from machining zone are the primary factors which cause large vibrations, higher grinding forces and poor surface quality. On-machine tool preparation and tool texturing prior to micro-grinding can reduce tool re-clamping error. It can further help to reduce the tool-workpiece contact area along with enhanced chip removal from the machining zone specifically essential during dry micro-grinding as usage of the cutting fluid should be minimized or completely avoided for environmental aspects. In this study, end faces of polycrystalline diamond (PCD) micro-tools have been on-machine textured using micro electro-discharge machining (micro-EDM) process. Four types of textured tools are envisaged viz. tool with one micro-cavity at the center of the end face (T2), one micro-groove along the end face diameter (T3), two intersecting micro-grooves at the end face (T4) and four intersecting micro-grooves at the end face (T5). A new term “contact area ratio” is defined to explain the texture dimension on the end face of the micro-grinding tools. Performances of different micro-textured tools (T2, T3, T4 and T5) with respect to a normal commercial tool (T1) in terms of grinding force, surface roughness and micro-slot quality are investigated for micro-slot grinding of BK7 glass. It is observed that micro-textured micro-grinding tool efficiently serves the purpose of provisional chip collection in passive grinding areas of the tool whereas chip adhesion or wear on the active grinding areas significantly gets reduced as compared to un-textured tools. Maximum reductions in the x and y direction forces are observed with tool type T5 compared to all other tool types. Reduction in z direction force is comparable for both tool types T2 and T3. Average surface roughness decreased from tool type T1 to type T2, T3 and up to tool type T4 whereas it again increased for tool type T5. The current study shows that textured micro-grinding tools are capable of reducing high normal forces, surface roughness and material dragging which are major concerns during micro-grinding with flat-end polycrystalline diamond tools.