Optical Photomicrographs Research Articles

Polydioxanone Bioactive Sutures-Acetyl Hexapeptide-8 (Argireline): An Intelligent System for Controlled Release in Facial Harmonization.

We propose a new facial lifting protocol using polydioxanone (PDO) threads embedded in acetyl hexapeptide-8 (Argireline [Arg]). We assume that Arg reinforces the effects of PDO threads, as it is a mimetic of botulinum toxin. Because the PDO suture is hydrolyzable, this assumption is analyzed by instrumental analysis. To demonstrate the capacity of the PDO suture as a system for the controlled release of acetyl hexapeptide-8 to apply in deep wrinkles of the upper third. Three segments of 1-cm long 21G PDO threads immersed in 1 mL of Arg. PDO threads were observed under an optical, electron microscope at 24, 48, and 72 h later. They were also weighed before and after being soaked in Arg, and employing ultraviolet (UV)-visible spectroscopy, the release rate of Arg from the PDO suture was measured. Finally, was insert the thread PDO-Arg following a protocol designed especially for deep static wrinkles in the upper third. The electronic weighing revealed that the PDO thread enjoys capillarity by the peptide, doubling its weight every 24 h. UV spectra revealed that PDO thread is a well-controlled release system for Arg, allowing its sustained release for 1 h. Optical and electronic photomicrographs confirm the swelling of the PDO thread by absorbing Arg by its capillarity, but this hydrophilicity does not lead to its premature physical degradation. The PDO thread system with Arg is an intelligent bioactive system useful in facial harmonization. It recommend conduct clinical trial to verify his superior lifting effect.

Quantification analysis of geometric characteristics of micro crack network on fault rock surface

Faults are common water conduits in coal mines, with variable permeability based upon the extent of cracks along the fault plane. In this study, three samples from a fault were obtained from a mining area in Southwest Shandong, China to determine the geometric characteristics, including crack density, fractal dimension, and crack connectivity. For microstructural analysis of fault rock specimens, scanning electron microscopy (SEM), x-ray diffraction (XRD), and plane-polarized light microscopy tests were used, and the geometric characteristics were calculated. A nonuniformity coefficient that considers the mineral composition is proposed to describe the micro-crack network of fault rocks. The results show that there is a significant positive correlation among three geometric characteristic parameters, and the nonuniformity coefficient is positively correlated with those parameters of the crack network. The crack extension forms of the three fault rock samples are different, which is related to the different fracture toughness of the mineral particles. The optical photomicrographs and SEM images show that crack networks are most developed in the samples with the least clay content. There is a negative correlation between clay content and the geometric parameters of the crack network, which may be related to the friction coefficient of clay.

Investigations on flexural strength of multi-material ABS based composite specimen fabricated through FDM technique

3D printing of thermoplastic polymers is one of the common techniques for fabricating structural and non-structural components for engineering, aerospace, construction and household applications. But hitherto very less work has been performed on 3D printing of secondary recycled acrylonitrile butadiene styrene reinforced with industrial wastes such as bakelite powder, Fe powder and wood dust. So, in this research work flexural specimens were printed through fused deposition modelling technique form composite filaments prepared in-house (secondary recycled ABS 90% by weight reinforced with equal percentage of bakelite powder, Fe powder and wood dust) as per Taguchi’s L9 orthogonal array. The influence of three FDM parameters (raster angle, infill density and infill speed) on the flexural strength of the fabricated specimen was also investigated and the results were analyzed using optical photomicrographs and scanning electron microscopy characterization. Optimal parametric settings for obtaining maximum peak strength (flexural) were 0° raster angle, 20 mm/sec printing speed and 80% infill density.

Study of the Behavior of Structural Materials Treated with Bioconsolidant.

In this article, the effectiveness of the bioconsolidation technique applied to degraded structural materials is illustrated as a new method of consolidation and conservation of the existing building heritage in a less invasive way. Satisfactory results have been obtained by an experimental campaign carried out through non-destructive diagnostic tests, static destructive mechanical tests, and microstructural analyses on a series of natural stone material specimens and artificial stone materials before and after the use of bioconsolidants. The consolidated specimens have been tested after three to four weeks after the application of the M3P nutritional solution on each specimen. The effect on the microstructure of this technique has also been observed using scanning electron microscope and optical photomicrograph, the formation of new calcium carbonate crystals promoting the structural consolidation of the materials under examination was observed in all the specimens analyzed.

On flexural, wear and morphological properties of 3D printed almond skin powder reinforced PLA matrix

ABSTRACT In past one decade, some studies have been reported on use of natural fibre-reinforced thermoplastic matrix such as polylactic acid (PLA)-based 3D-printed functional prototypes for biomedical applications. But hitherto little has been reported on the flexural, wear and morphological properties of almond skin powder–-reinforced PLA matrixbased 3D-printed functional prototypes prepared by fused filament fabrication (FFF) as biomedical scaffold/implant. In this study, the 3D-printed functional parts were subjected to flexural, wear and morphological investigations. The results suggested that maximum flexural strength at break and peak was observed as 57.38 MPa and 63.761 MPa, respectively (while printing with FFF at infill density 60%, infill angle 60° and infill speed 70 mm/s). The results are supported with the optical photomicrographs and surface topography analysis, which shows that there is relation between mechanical and surface properties of functional prototypes. The minimum surface roughness (Ra) 19.98 nm has been observed for 3D-printed flexural samples at proposed settings.

Thermomechanical and morphological properties of sustainable mortars employing blast furnace slag and fly ash reinforced cement

The blast furnace slag (BFS) is non-metallic co-product (such as silicates and alumina silicates etc.) which absorbs sulphur from the charge and comprises of around 20% (by weight) of Fe production and its use as reinforcement in cement mortar has been widely explored to improve thermal and compressive properties along with addressing the sustainability issues related to Fe production. But hitherto little has been reported on effect of BFS and fly ash (FA) reinforced cement mortar from surface topography, thermal stability and morphological properties view point. This paper reports the comparison of compressive, thermal and morphological properties of cement mortar with air cooled BFS and FA reinforced cement mortar as a case study. The results of study suggests that 80% of BFS and 20% FA reinforced cement mortar (cement: (BFS+FA): 1: (0.8+0.2) by weight%) possess lowest thermal conductivity (0.65W/mK), greatest porosity (29.65%) and acceptable compressive strength (6.6MPa) in comparison to cement mortar comprising of cement: sand as 1:1. The results are supported with compressive strength data, optical photo micrographs, thermal analysis based upon differential scanning calorimetry (DSC), surface topography (based upon 3D rendered images).

Friction-stir-spot welding of 3D printed ABS and PA6 composites: flexural, thermal and morphological investigations

ABSTRACT In past one decade friction-stir-spot welding (FSSW) has been established as one of the commercially acceptable joining process for thermoplastics. But hitherto little has been reported on the effects of semi-consumable/fully consumable rapid tooling (RT) in FSSW. The present study reports the joining of fused deposition modelling (FDM) printed dissimilar thermoplastic composite materials (acrylonitrile butadiene styrene (ABS) and polyamide6 (PA6) both extrusion grade) as a case study of FSSW by using melt flow compatible RT. The study suggested that 15% Al metal particulate reinforcement to ABS and 50% Al reinforcement to PA6 exhibits melt flow compatibility with feasibility of FSSW. The FSSW of dissimilar materials suggested that 1400 rpm rotational speed; 20 s stirring time and 2 mm pin depth of RT resulted into superior flexural strength (FS) and thermal properties. The results are also supported by thermal images, force measurement and optical photo-micrographs.

Multi material 3D printing of PLA-PA6/TiO2 polymeric matrix: Flexural, wear and morphological properties

The poly-lactic acid (PLA), bio compatible polyamide (PA6) and TiO2 has established bio-medical applications especially in 3D printing of scaffolds. But hitherto little has been reported on improving the performance of multi-material matrix for PLA-PA6/TiO2 especially in 3D printing application of biomedical scaffolds. The anti-bacterial properties of PA6/TiO2 make it worthy to be explored with PLA matrix in multi layered fashion on the platform of fused deposition modeling (FDM) being low cost 3D printing technology for in house development of scaffolds. In this work an effort has been made for in-house development of feedstock filaments of PLA and PA6/TiO2 based polymeric composite matrix on twin screw extrusion (TSE) machine. Further the feedstock filament wires were used on FDM to establish the flexural, wear and morphological properties of multi-material 3D printed functional prototype. The results of the study suggest that for flexural strength, infill speed: 90mm/s; infill pattern: triangular and layer combination as 5 consecutive layers of PLA and 5 consecutive layers of PA6/TiO2 are the optimized conditions for FDM printing. The wear testing results suggest that the composite of PA6/TiO2 held low wear rate (823 µm) in comparison to PLA (wear rate: 1092 µm). Further porosity testing (based upon optical photomicrographs) at ×100 and fractured surface analysis at ×30 supported the observed trends for flexural and wear testing. The photomicrographs of fractured surface were 3D rendered to predict the role of surface roughness (Ra) profile for flexural properties. The mechanical and morphological observations are also supported with scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analysis.

3D printed tensile and flexural prototypes of thermoplastic matrix reinforced with multi-materials: A statistical analysis

Fused deposition modelling (FDM) is one of the established low cost 3D printing techniques for preparation of functional/ non functional prototypes from thermoplastic composite matrix (prepared as multi/ hybrid blended material). But hitherto little has been reported on multi material reinforced thermoplastic matrix in successive 3D printed layers from repeatability view point. Since the adaptability of any processing technique is dependent upon repeatability/ reproducibility (for which the process output must be statistically controlled), this work reports the statistical analysis of 3D printed tensile and flexural samples printed on FDM as functional prototypes of poly lactic acid (PLA) matrix reinforced with multi materials (poly vinyl chloride (PVC), wood dust and magnetite (Fe 3 O 4 ) powder) as functionally graded thermoplastic matrix. Further in this work functional prototypes of tensile and flexural sample were 3D printed and tested for their mechanical properties to analyze the process capability index (Cp and Cpk) along with morphological characteristics using optical images of the fractured surfaces. The result of the study suggests that the process was observed to be in statistical control as Cp and Cpk was found to be more than 1 for tensile and flexural properties. Based upon optical photo micrographs it has been ascertained that the optimized 3D printing parameters resulted into uniform morphological features (based upon surface roughness (Ra) and amplitude distribution function (ADF), peak count (PC) and bearing ratio (BR) curve).

Green Synthesis Characterization and Thermotropic Behaviour of O-Linked Glycopyranosides of Phenolic Esters

Focusing on green chemistry protocols, a series of carbohydrate derivatives (5a–l) have been synthesized by Fischer glycosylation of α-D-glucose, D-xylose, and α-maltose with several nonpolar phenolic ester aglycones (3a–d) derived from menthol by employing solid-supported Si-H+ as the catalyst. In order to study the extent of mesomorphism in target molecules, the thermotropic behaviour has been studied by using the thermoanalytic DSC/TGA technique and polarized optical microscope. Phase transitions in the DSC thermograms of 5a–l with two endothermic melting point peaks and various exothermic crystalline transitions exhibits the existence of mesophases. However, optical photomicrographs revealed that the new glycopyranosides formed smectic A phases. Moreover, all the compounds (3a–d and 5a–l) were confirmed by FTIR and 1H NMR.

Neogene Tree Trunk Fossils from the Meshgin Shahr Area, Northwest Iran

In 2016, an extensive fossil forest was discovered near Meshgin Shahr, northwest Iran. Silicified tree trunks occur in Miocene fluvial sediments and at multiple stratigraphic levels within a 27-m thick sequence of Pleistocene volcaniclastics. The Miocene trunks likely represent stream transport. Pleistocene examples originated during repeated eruptive events when volcaniclastic sediments buried a standing forest. The site, informally named Meshgin Shahr Fossil Forest, was registered in 2017 as a national natural monument by the Iranian Cultural, Handicraft and Tourism Organization. To date, 16 fossilized trunks have been found, all but one of them representing gymnosperms. The ancient coniferous forest was very different from modern forests in Iran and adjacent Azerbaijan, a result of climatic changes that were principally caused by the demise of the Paratethys Sea and by rain shadow effects caused by the uplift of the Alborz and Zagros mountain ranges. X-ray diffraction patterns reveal that woods from the fossil forest contain three types of silica: opal-CT, pure quartz, and a mixture of opal-CT and quartz. In addition, optical photomicrographs show the abundant presence of amorphous opal-A. Mineralogic variations occur among different fossil trees and within a single trunk. These silica polymorphs resulted from a combination of processes: silica minerals precipitated in multiple episodes under differing geochemical conditions and the diagenetic transformation of an opaline parent material.

On multi-factor optimisation of Ni-Cr-based partial dentures by centrifugal casting

ABSTRACT The conventional centrifugal casting of Ni-Cr (N)-based alloys is commercially established process for the preparation of partial/complete dentures. But hitherto little has been reported on the multi-factor optimisation of N-based alloys in conventional centrifugal casting. This study concentrates on preparation of N-based partial dentures by using lost wax technique in different proportions (by weight %) of Ni (R) as an input parameter. The other input parameters were investment powder to water ratio (P) and pH value (Q) of water used (for mixing the investment). The samples prepared were subjected to measurement of dimensional deviation/accuracy (Δd), surface roughness (Ra) and micro hardness (HV). Finally, after obtaining required properties, multi-factor optimisation has been performed. The results are supported by optical photomicrographs (2D and 3D rendered images). The results of study highlight that N-based partial denture cast at best settings of input parameters (i.e. P (100/12), Q (pH 7) of water with R (61%) gives overall better performance and in-vitro analysis indicates that the partial dentures cast with R (65%) showed the maximum biocompatibility with NIH3T3 cells and are capable of supporting cell proliferation and cell adhesion.

Secondary recycled acrylonitrile–butadiene–styrene and graphene composite for 3D/4D applications: Rheological, thermal, magnetometric, and mechanical analyses

This study reports investigation on nano-sized (5–10 nm) graphene (Gr)-reinforced, secondary (2°) recycled acrylonitrile–butadiene–styrene (ABS) as a smart composite material for 3D and 4D applications. Gr was blended (in different weight proportions) with 2°-recycled ABS granules mechanically for selection of composition/proportion after ascertaining rheological property (based upon melt flow index according to ASTM D 1238), thermal stability based upon differential scanning calorimetry, and magnetic property based upon vibration sample magnetometry. The selected compositions/proportions of ABS-Gr composite was further processed with a twin-screw extruder by varying screw temperature and torque. The results of the study suggest that as regards to mechanical properties (peak strength and Shore D hardness) are concerned, the best settings are 20 wt% Gr reinforcement in ABS at a screw temperature 210°C with torque of 0.4 Nm. The corresponding heat capacity and magnetization for the selected composition/proportion was observed as 0.77 J/g and 0.10 × 10−5 emu (+magnetization), 0.080 × 10−5 emu (−magnetization), respectively. The coercivity of the selected compositions ranges from 79.19 Oe to 1260.34 Oe (+coercivity) and 4.64 Oe to 639.50 Oe (−coercivity), whereas the retentivity of the investigated compositions ranges from 2.36 × 10−5 G to 5.44 × 10−4 G (+retentivity) and 4.31 × 10−5 G to 3.48 × 10−5 G (−retentivity). The results have been counter verified based upon optical photo micrographs, porosity analysis, scanning electron microscopy analysis, and energy-dispersive spectroscopy analysis.

On compressive and morphological features of 3D printed almond skin powder reinforced PLA matrix

This paper reports the compressive, morphological and surface hardness properties of almond skin powder reinforced polylactic acid (PLA) matrix based 3D printed functional prototypes prepared by fused filament fabrication (FFF) as biomedical scaffolds. In this study the 3D printed functional parts were subjected to compression, morphological and Shore D hardness investigations. The results of this study highlight that maximum compressive strength at peak (37.712 MPa), maximum compressive strength at break (33.93 MPa) and Young’s modulus (387.80 MPa) was observed in case of sample printed at infill density 100%, infill angle 90° and infill speed 70 mm s−1 (as per ASTM D695). The maximum modulus of toughness as 3.47 MPa was observed in the case of printed sample at infill density 60%, infill angle 60° and infill speed 70 mm s−1. The results are supported by optical photomicrographs and Shore D hardness. Finally mathematical equations were developed (as empirical model) to predict different mechanical properties (based upon historical data approach) supported by Taguchi analysis.

A simple morphometric analysis method for dermal microstructure using color thresholding and moments.

Proper assessment of dermal collagen fibers by dermatologists and researchers is essential. Histologic evaluation methods have limitations. We present a simple method for measurement of collagen fibers in human skin using Masson's trichrome staining. Normal skin specimens from a cadaver were processed with Masson's trichrome, which can effectively stain collagen fibers blue with aniline dye. Optical photomicrographs of these slides were analyzed using ImageJ software. Color image processing, a histogram-based function of ImageJ for image segmentation, was performed with color moments thresholding technique. We selected blue areas by adjusting the blue channel to include specific values. The selected areas were highlighted and evaluated. We divided the image into layers of 0.09-mm2 areas from the top to bottom of the dermis. Each area was cropped and evaluated. Quantitative assessment yielded the quantitative size occupied by collagen fibers in an area of 0.09mm2 . Calculation of the percentage in each area can be used to determine the density of collagen fibers. Measurements obtained with our method can be applied to research on dermal collagen fibers. We present a convenient quantitative assessment method for the dermal constituents in Masson's trichrome-stained slides.

Researches Concerning Chemical Modifications of Hair Keratin

The work presents chemical procedures used to obtain a film or a hydrogel after hydrolyze treatment of hair at the temperature of 150oC and the pressure of 4.9 atm. In order to obtain the hydrogel, this treatment is followed by a stage of oxidation with hydrogen peroxide, and a stage of reduction with Na2S2O4 or, in another variant, a stage of oxidation with hydrogen peroxide and a treatment with NaOH in alcoholic medium, to form natrium cationic groups. The protein chains with sulphonic groups and natrium cations determine opposite electrostatic interactions, with the formation of a polymer loop that incorporate water. The evaluation of formed hydrogel was carried out by determining the swelling degree. We have used optical and SEM photomicrographs to determine morphological organization, and EDAX micropictures for chemical modifications. A cellulose film realized by growing Gluconoacetobacter xylinus bacteria was used as control sample.

Novel optical image analysis coke characterisation and its application to study of the relationships between coke Structure, coke strength and parent coal composition

To better understand the connection between parent coal blend, coke structure, and coke strength novel structural identification and characterisation techniques for processing high resolution optical photomicrographs of coke were developed. Automated segmentation of inert maceral derived components (IMDC) and reactive maceral derived components (RMDC) allowed measurement of a broad range of parameters characterising coke structure. The characterisation included separate characterisation of IMDC and RMDC, IMDC boundaries including calculation of parameters characterising connections between IMDC and RMDC, coke porosity and, separately, IMDC porosity.Several other novel approaches using image analysis software were investigated, such as:•Separation of large porosity objects into individual pores (Separated Pores),•Removal of weak walls and hence potential identification and measurement of Weak Areas,•Identification of nodes (relatively thick agglomerations in the coke structure) and walls (part of the coke matrix connecting nodes),•Measurement of Modified Wall Thickness (when only walls are taken into account), Wall Neck Thickness (weakest points in walls) and Specific Neck Thickness (sum of all necks per unit area).Application of these novel characterisation techniques to a set of coke samples produced a substantial amount of data, which revealed many strong correlations between novel parameters characterising coke structure, and also between these parameters, coke strength indices and parent coal composition. This demonstrated the usefulness of the newly developed characterisation methodologies and gave a significantly improved understanding of coke structure and its connection with coke strength and parent coal blend. It should also be noted that these novel approaches to structural/textural characterisation can be applied to carbonaceous materials other than coke or other structural materials such as sinter, ore, and ceramics.

The effect of the grafted chains on the crystallization of PLLA/PLLA-grafted SiO2 nanocomposites

Two types of homemade poly(l-lactide) (PLLA)-grafted SiO2 nanoparticles with totally different topological structures are introduced into PLLA to prepare PLLA nanocomposites with different interface interactions and study the effect of the topology of polymer grafted nanoparticle on crystallization of PLLA. Differential scanning calorimetry (DSC) and polarized optical photomicrographs (POM) results show that the crystallization rate of PLLA has been greatly improved by the introduction of grafted SiO2, due to the improved heterogeneous nucleating effect. The nucleation constant of the two modified nanoparticles is evaluated by Hoffman–Lauritzen analysis; it is suggested that by introducing modified nanoparticles with long grafted chains, the interaction between the nanofiller and PLLA matrix will be enhanced, leading to the improved nucleation effective (the larger nucleation constant Kg), and the changed crystalline morphology, from large spherocrystals to tiny crystals. These observations are explained on the basis of different nucleation mechanism caused by the different surface structures of grafted SiO2, through the application of time-resolved Fourier transform infrared (FTIR) spectroscopy in the molecular level. The special long grafted PLLA chains can be acted as a more efficient nucleating agent for PLLA, and the conformational ordering of PLLA during the crystallization is significantly influenced by the topology of modified nanoparticles.

Microscopic study of the morphology and metabolic activity of Fusarium oxysporum f. sp. gladioli treated with Jatropha curcas oil and derivatives

The fungus Fusarium oxysporum f. sp. gladioli is one of the main pathogenic microorganisms of the ornamental genus Gladiolus. The attack of this microorganism includes corms and different plant phenological stages. In this study, different microscopic techniques and fluorochromes were used to evaluate the effect of J. curcas oil and acylglycerides, namely trilinolein, triolein, monomyristin and dimyristin, on the morphology, membrane integrity (%), viability (%) and germination (%) of F. oxsporum f sp. gladioli. Phase-contrast optical photomicrographs and scanning microscopy showed that J. curcas oil and the triglycerides triolein and trilinolein caused the formation of numerous vacuoles, alterations in the morphology of the outer covering of the mycelium and conidia, and inhibition of membrane activity in the fungus during 24h of incubation. The fluorochromes used detected no permanent damage to the viability of the conidia. The high germination percentage of the conidia of Fusarium oxysporum f. sp. gladioli indicates that the damage caused by the application of the treatments was fungistatic rather than fungicidal and did not cause cell death.

Mechanical properties of low alloy high phosphorus weathering steel

Mechanical behaviour of two low alloy steels (G11 and G12) was studied with respect to different phosphorus contents. Tensile strength and yield strength increased while percentage elongation at fracture decreased on increasing phosphorus content. The SEM and light optical photomicrograph of low phosphorus steel (G11) revealed ferrite and pearlite microstructure. On increasing phosphorus content from 0.25 wt.% to 0.42 wt.%, the morphology of grain changed from equiaxed shape to pan-cake shape and grain size also increased. The Charpy V notch (CVN) impact energy of G11 and G12 steel at room temperature was 32 J and 4 J respectively and their fractographs revealed brittle rupture with cleavage facets for both the steels. However, the fractograph of G11 steel after tensile test exhibited ductile mode of fracture with conical equiaxed dimple while that of G12 steel containing 0.42 wt. % P exhibited transgranular cleavage fracture. Based on this study, G11 steel containing 0.25 wt. % P could be explored as a candidate material for weathering application purpose where the 20?C toughness requirement is 27 J as per CSN EN10025-2:2004 specification.