Coat Surface Research Articles

Seed morphology of the subfamily Helleboroideae (Ranunculaceae) and its systematic implication

A comprehensive morphological and anatomical study was carried out on seeds of 28 species from three tribes and eight genera of subfamily Helleboroideae (Aconitum, Actaea, Caltha, Cimicifuga, Delphinium, Eranthis, Megaleranthis and Trollius) and two putatively related genera in Ranunculaceae (Adonis and Ranunculus) using scanning electron and light microscopy to evaluate seed characteristics for use in the examination of systematic relationships. Considerable differences were found in seed coat morphology and anatomy both among and within genera of the subfamily. There are four major types of seed coat surface: striate, lineate, colliculate and irregularly wrinkled. The shape of testal cells was either elongated rectangular, rectangular chiseled, irregular or polygonal to subpolygonal. The wall ornamentation was predominantly smooth and either without any ornamentation or having finely granulated or some ribbon like appendages. The mechanical layer of the seed coat was of the exotestal type except in all species of Eranthis, in which the seed coat mechanical layer was absent; such a seed coat was referred to as being an ‘undifferentiated seed-coat’. Maximum parsimony analysis of morphological features establishes three groupings within the studied genera: Aconitum/Delphinium, Actaea/Cimicifuga, and Caltha/Eranthis/Trollius/Megaleranthis. This study is congruent with the earlier groupings of the Helleboroideae based on morphology and also agrees in part with recent molecular studies. Our data convincingly support a close relationship between Caltha–Trollius–Megaleranthis and between Actaea and Cimicifuga. Another group supported strongly by the results of this study is Aconitum–Delphinium.

Healing of the Interface Between Splashed Particles and Underlying Bulk Coating and Its Influence on Isothermal Oxidation Behavior of LPPS MCrAlY Bond Coat

The thermally grown oxide formed on the bond coat surface plays an important role in determining the lifetime of thermal barrier coatings (TBCs). The splashed particles on the thermally sprayed MCrAlY bond coat surface are weakly bonded to the underlying bulk coating, leading to the formation of mixed oxides and contributing to the TBC failure. In this study, the healing behavior of the weakly bonded interface between splashed particles and underlying MCrAlY bulk coating deposited by low pressure plasma spraying was examined, and the influence of interface healing on the isothermal oxidation behavior of the bond coat was discussed. Results show that the granular particles resulting from splashing of molten droplets were exposed on smooth splats which make up the surface of bulk coating. After the pre-diffusion treatment in vacuum, the small granular splashed particles are immersed into the bulk coating resulting from the element diffusion on the interface between splashed particles and underlying bulk coating. After the vacuum heat treatment, the formation of mixed oxides was effectively restrained due to the healing of the splashed particle/underlying bulk coating interface.

Influence of bond coat surface roughness on the structure of axial suspension plasma spray thermal barrier coatings — Thermal and lifetime performance

Suspension plasma spraying has become a very promising candidate for the production of strain tolerant coatings for the gas turbine industry. Under certain process conditions suspension plasma spraying (SPS) generates column-like structures in the produced coatings. While a mechanism for column formation has been suggested previously based on columns forming on surface asperities, the effect of modification of surface structures on SPS coating properties has not been investigated.In this study, the surface topography of bond coats within a TBC system were modified by the combination of polishing and surface grit blasting. Yttria stabilized zirconia coatings were deposited using an axial feed suspension plasma spray gun. The surface topography of the resultant coatings was characterized using striped light projection. Samples were tested for thermo-cyclic fatigue lifetime at 1100°C during 1hour cycles. Thermal shock performance was evaluated using the burner rig test and thermal conductivity evaluated using the laser flash analysis. The results indicate that columnar SPS coating microstructure is strongly influenced by surface topography. Test results suggest that control of surface topography may be an important factor to improve the performance of SPS coatings.

Diversity of selected Lupinus angustifolius L. genotypes at the phenotypic and DNA level with respect to microscopic seed coat structure and thickness.

The paper investigates seed coat characteristics (as a percentage of overall seed diameter) in Lupinus angustifolius L., a potential forage crop. In the study ten L. angustifolius genotypes, including three Polish cultivars, two Australian cultivars, three mutants originated from cv. ‘Emir’, and one Belarusian and one Australian breeding line were evaluated. The highest seed coat percentage was recorded in cultivars ‘Sonet’ and ‘Emir’. The lowest seed coat thickness percentage (below 20%) was noted for breeding lines 11257-19, LAG24 and cultivar ‘Zeus’ (17.87%, 18.91% 19.60%, respectively). Despite having low seed weight, the Australian line no. 11257-19 was characterized by a desirable proportion of seed coat to the weight of seeds. In general, estimation of the correlation coefficient indicated a tendency that larger seeds had thinner coats. Scanning Electron Microscopy images showed low variation of seed coat sculpture and the top of seeds covered with a cuticle. Most of the studied genotypes were characterized by a cristatepapillate seed coat surface, formed by elongated polygonal cells. Only breeding line no. 11267-19 had a different shape of the cells building the surface layer of the coat. In order to illustrate genetic diversity among the genotypes tested, 24 ISSR primers were used. They generated a total of 161 polymorphic amplification products in 10 evaluated narrow-leaved lupin genotypes.

Tongue Inspection in TCM: Observations in a Study Sample of Patients Living with HIV.

Background: One of the principal diagnostic methods in Traditional Chinese Medicine (TCM) is the inspection of the tongue. This method involves examination of the shape, size, color, and texture of the tongue body and coat and helps reveal the state of organ functions and progression of conditions. Literature on tongue observations for patients who have human immunodeficiency virus (HIV) is minimal. Objective: The goal of this study was to provide a clinical "snapshot" of initial tongue assessments of 159 patients living with HIV, who participated in an acupuncture clinical trial for chronic nausea. The aim was to explore the similarities and differences observed in tongue assessments. Design: This study was part of a prospective, randomized, controlled, double-blinded (subjects and evaluators), parallel-groups, acupuncture clinical trial for treating chronic nausea. Setting: The study was conducted at a large urban New York City academic health center. Patients: The patients in this study were 159 individuals who had HIV infections and who had histories of chronic nausea for ≥3 months. Main Outcome Measures: Initial tongue assessments were recorded for seven basic characteristics: (1) tongue color; (2) tongue shape; (3) tongue body quality; (4) coat color; (5) coat weight; (6) coat surface; and (7) tongue action. Results: The overall tongue picture seen in these patients was that the tongue was swollen and toothmarked, had a pink body with cracks, and had a thick, dry white coat. Conclusions: The HIV disease itself and the use of long term medications affect the Blood, Qi, Yin, and Yang. The observation of the tongue provides a window into the process of the disease and, ultimately, insight for clinical care. This sample population snapshot illustrates the complex processes seen in long-term chronic conditions managed by pharmacologic medications.

Spore Formation and Toxin Production in Clostridium difficile Biofilms

The ability to grow as a biofilm can facilitate survival of bacteria in the environment and promote infection. To better characterize biofilm formation in the pathogen Clostridium difficile, we established a colony biofilm culture method for this organism on a polycarbonate filter, and analyzed the matrix and the cells in biofilms from a variety of clinical isolates over several days of biofilm culture. We found that biofilms readily formed in all strains analyzed, and that spores were abundant within about 6 days. We also found that extracellular DNA (eDNA), polysaccharide and protein was readily detected in the matrix of all strains, including the major toxins A and/or B, in toxigenic strains. All the strains we analyzed formed spores. Apart from strains 630 and VPI10463, which sporulated in the biofilm at relatively low frequencies, the frequencies of biofilm sporulation varied between 46 and 65%, suggesting that variations in sporulation levels among strains is unlikely to be a major factor in variation in the severity of disease. Spores in biofilms also had reduced germination efficiency compared to spores obtained by a conventional sporulation protocol. Transmission electron microscopy revealed that in 3 day-old biofilms, the outermost structure of the spore is a lightly staining coat. However, after 6 days, material that resembles cell debris in the matrix surrounds the spore, and darkly staining granules are closely associated with the spores surface. In 14 day-old biofilms, relatively few spores are surrounded by the apparent cell debris, and the surface-associated granules are present at higher density at the coat surface. Finally, we showed that biofilm cells possess 100-fold greater resistance to the antibiotic metronidazole then do cells cultured in liquid media. Taken together, our data suggest that C. difficile cells and spores in biofilms have specialized properties that may facilitate infection.

Morphology of the seed coat of Oxalis spp. from Buenos Aires Province (Argentina)

The aim of the present study is to provide detailed morphological descriptions of the seed coat in 10 species of Oxalis from Buenos Aires Province, Argentina, using light microscopy and scanning electron microscopy. The seed is ovate and brown, and its surface is smooth. Oxalis has a mechanism of spermobolia by which a part of the seed coat is detached by the rupture of cells, leaving exposed a layer of opened cells, generally with oxalate crystals. This new coat surface has different characteristics in the species studied in this work. Three types are recognized, mostly on the basis of anatomical and ultrastructural characteristics of the seed coat. The species grouped in each of the 3 types of seeds belong to different sections of the genus; thus, the seed morphology could be of taxonomic value for the genus Oxalis.

Parasites of domestic owned cats in Europe: co-infestations and risk factors.

BackgroundDomestic cats can be infested by a large range of parasite species. Parasitic infestations may cause very different clinical signs. Endoparasites and ectoparasites are rarely explored in the same study and therefore multiparasitism is poorly documented. The present survey aimed to improve knowledge of the prevalence and risk factors associated with ecto- and endoparasite infestations in owned cats in Europe.MethodsFrom March 2012 to May 2013, 1519 owned cats were included in a multicenter study conducted in 9 veterinary faculties throughout Europe (Austria, Belgium, France, Hungary, Italy, Romania and Spain). For each cat, ectoparasites were checked by combing of the coat surface associated with otoscopic evaluation and microscopy on cerumen samples. Endoparasites were identified by standard coproscopical examinations performed on fresh faecal samples. Risk factors and their influence on parasitism were evaluated by univariate analysis followed by a multivariate statistical analysis (including center of examination, age, outdoor access, multipet status, and frequency of treatments as main criteria) with logistic regression models.ResultsOverall, 50.7% of cats resulted positive for at least one internal or one external parasite species. Ectoparasites were found in 29.6% of cats (CI95 27.3-32.0%). Otodectes cynotis was the most frequently identified species (17.4%), followed by fleas (15.5%). Endoparasites were identified in 35.1% of the cats (CI95 32.7-35.7%), including gastro-intestinal helminths in 25.7% (CI95 23.5-28.0), respiratory nematodes in 5.5% (CI95 4.2-7.0%) and protozoans in 13.5% (CI95 11.8-15.3%). Toxocara cati was the most commonly diagnosed endoparasite (19.7%, CI95 17.8-21.8%). Co-infestation with endoparasites and ectoparasites was found in 14.0% of the cats, and 11.9% harbored both ectoparasites and gastro-intestinal helminths.Age, outdoor access, living with other pets, and anthelmintic or insecticide treatments were significantly associated with the prevalence of various parasites.ConclusionsThis survey demonstrates that parasitism is not a rare event in European owned cat populations. The prevalence of multi-parasitism is significantly greater than expected by chance and hence there is tendency for some individual cats to be more prone to infestation by both endo- and ectoparasites due to common risk factors.

Enhancement of Seed Germination in Trema orientalis (L.) Blume—Potential Plant Species in Revegetation of Mine Wastelands

Natural forest succession takes a long time to accumulate sufficient nutrients to support plant growth and enhance soil microbial activity. Human intervention in selecting native pioneer plant species is therefore required to accelerate sustainable restoration. Trema orientalis (L.) Blume, a fast growing pioneer plant species, has the ability to grow in nutrient deficient soils and proves to have reclamation potential in mine wastelands. However, its use has been limited due to low germination percentages and nonsynchronous seed germination. In the present study we tested the effect of sulphuric acid (H2SO4), hydrochloric acid (HCl), gibberellic acid (GA3), and potassium nitrate (KNO3) in varying concentrations and time durations on germination percentages and seed germination synchrony. We found that all treatments had a significant effect in predicting seed germination probabilities. Logistic regression analysis revealed that treatment solution and concentration had a significant effect on seed germination. Treatment with concentrated H2SO4 for 15 min increased germination up to 92% within 20 days with the least imbibition time (8 days) and highest Seedling Vigor Index (491). The scanning electron microscope images of seeds treated with H2SO4 showed complete dissolution of the honeycomb-like network of deposits on the seed coat surface removing the physical barrier and enhancing germination.

Importance of birthcoat for lamb survival and growth in the Romane sheep breed extensively managed on rangelands

The Romane sheep breed proved to be adapted to harsh conditions with high prolificacy and lamb survival in outdoor farming, even under bad climate conditions. This breed shows large variability in its fleece type at birth and it has been suggested that lamb survival could be related to birthcoat type. The aim of the present study was to: i) characterize the coat of the lamb at birth and quantify lamb survival in relation to the birthcoat type and its protective properties concerning heat loss in the Romane breed raised under permanent exposure outdoors from birth, and ii) estimate genetic parameters of birthcoat type in relation to lamb survival and live body weight. A total of 7,880 lambs from 104 sires and 1,664 dams were used in a 14-yr experiment. The pedigree file included 9,625 individuals over 15 generations. Birthcoat type, coat surface temperature, coat depth, lamb survival, and growth were measured from birth to weaning. Weather data (temperature, wind speed, relative humidity, and precipitation) were recorded daily during lambing time. Two types of coats were observed at birth: hairy coat (62.9% of lambs) with a long coat depth (average 23.3 mm) or woolly 1 (37.1% of lambs) with a short coat depth (average 8.3 mm). Birthcoat type was an important factor affecting lamb survival and growth from birth in the Romane breed. Total mortality rate was significantly less in hairy-bearing coat lambs than in short-woolly coat ones: 7.0% vs. 9.6%, 11.6 % vs. 14.8%, and 15.7 % vs. 20.1 % at 2, 10, and 50 d, respectively, and the relative risks of death increased by 37%, 67%, and 46 % at 2, 10, and 50 d of age, respectively, in short-woolly lambs. At birth, a significant lower coat surface temperature, indicating less heat loss, was observed in long-hairy coat lambs compared with others (21.1°C vs. 26.1°C). Heavier body weights and better growth performances up to the age of 50 d were observed in long-hairy-bearing coat lambs. Lamb survival was positively correlated to weather conditions at lambing time in short-woolly lambs, whereas no relation was observed in hairy-coat lambs. Heritability estimate of birthcoat type (hairy or woolly) is high (0.88). Genetic correlations between birthcoat type, lamb survival, and live body weight at birth were positive and moderate, suggesting that it would be beneficial to take birthcoat into account as an adaptive trait in any genetic strategies for sheep production in harsh conditions on rangelands.

Determination of seal coat deterioration using image processing methods

Seal coat is the most commonly used asphalt pavement type due to its low initial construction cost and ease of application in countries such as Turkey, Australia, South Africa and New Zealand. Seal coat deterioration occurs over time because of the effect of various factors such as weather, traffic, etc. The determination and assessment of deterioration is an important components of pavement management systems (PMS). This article presents, digital image processing (DIP) techniques as effective and reliable measurement techniques for the determination of bleeding deterioration in seal coats. The developed technique was applied to a total of 140 images, taken from four survey sites in four different Highway Districts. These images were obtained with an image acquisition device that was developed to take images for this study. Each image was classified in one of two categories, namely, bleeding or satisfactory. One hundred seal coat images were classified as bleeding surfaces and the others were satisfactory surfaces. The edge detection algorithm was developed using the image processing toolbox of Matlab software. Aggregate edge patterns of bleeding or satisfactory seal coat surfaces differ significantly. Therefore, in this study was examined the edges of aggregate particles using seal coat images. The results show that bleeding deterioration on seal coat was determined accurately using the developed algorithm in the scope of study. The results also indicate that this system is a promising tool in seal coat surface condition evaluation, potentially aiding pavement engineers in prioritizing seal coat projects in a quantitative rather than qualitative manner.

37 RESTORING REPROGRAMMING ABNORMALITIES IN A CLONED DOG HAVING ECTOPIC LIVER AND GALL BLADDER BY RECLONING

The risk of reprogramming abnormalities such as placental hyperdevelopment, excessive fetal growth, or abnormalities of the immune system in cloned neonates is one of the major concerns in cloning research. However, until now, relatively few studies about birth defects have been reported in dog cloning, which might be due to the short in vitro manipulated procedure in this species. Here, we report a cloned dog having abnormal liver and investigated whether the abnormal liver was due to genetic modification. A cloned beagle was produced from a fibroblast derived from a 10-year-old donor, but accidentally died due to cannibalism of a nanny dog on the day of birth. During autopsy, an abnormal liver structure was found; 7 lobes were presented at the normal liver position inside the abdomen, but there was no gall bladder. Interestingly, 3 additional lobes with a gall bladder were found in between the rib and the skin. There were no other macroscopic anomalies observed in this puppy. To evaluate the heredity of this liver abnormality, the liver structure of the donor dog was diagnosed by computed tomography (CT). Also, to assess the possibility of restoring the liver abnormality, recloning was performed using a fibroblast cell line established from the dead pup, and liver positions in the recloned dogs were diagnosed by CT after puberty. In results, 2 recipients delivered 5 recloned dogs with birthweights of 510, 250, 460, 400, and 410 g. The smallest one showed severe bow-legged phenotype in its hind leg, and a unique coat pattern that showed the largest white coat surface. The pup died 10 days after birth, and no other abnormal phenotype was found during autopsy. The other 4 pups showed normal morphology at birth. The CT results showed normal positioning of the liver and gall bladder in all experimental dogs, including the original cell donor dog and recloned dogs. To our knowledge, there have been no reported cases of an ectopic liver and gall bladder present between rib and skin in both cloned and noncloned animals, and we consider that these abnormalities are not a due to genetic cause. Further studies regarding aberrant epigenetic reprogramming in the abnormal liver formation are needed.

Características morfológicas do pelame de vacas holandesas puras por cruza na região semiárida de Minas Gerais

O objetivo do trabalho foi avaliar as características morfológicas como densidade numérica e espessura do pelame e comprimento dos pelos de vacas Holandesas predominantemente negras, puras por cruza em lactação na região de Montes Claros no norte de Minas Gerais. O estudo foi conduzido em duas fases, A: julho/agosto e B: outubro/novembro de 2010, utilizando 12 fêmeas Holandesas em lactação, puras por cruza de pelame predominante negro. Foram medidas as características de densidade numérica (nº pelos/cm²), espessura (mm), comprimento (mm) e a temperatura da superfície do pelame (TPE). Os resultados mostraram que o pelame foi menos denso, com pelos mais curtos na fase B, no entanto a espessura não variou entre as duas fases. No período em que ocorreu maior densidade numérica houve menor TPE. As características do pelame das vacas Holandesas puras por cruza observadas indicam uma boa adequação às condições ambientais da região em estudo.

Virtual Geometrical Data Definition of Part with Unspecified Shape

The contribution deals with the geometrical data definition of part with unspecified variable radius by means of modern equipment and computer aid. There are described some problems that originate at the real part digitizing. The possibility of virtual 3D model creating is given due to the modern equipment so called scanners. After the sections of scanned model were created,their contours were interpolated or approximated by curves of Bezier and Spline type. The curves were covered with a coat surface created as a Pro/Engineering systems own element, so the geometrical data were readable also for CAM system area. The virtual model serves for the generating of CL data to make new part on NC/CNC machine. The manufacturing of the part with CNC machine utilization enables to increase the production efficiency and the part quality.

Temperature and thermal stress analyses of a ceramic-coated aluminum alloy piston used in a diesel engine

The goal of this paper is to determine both temperature and thermal stress distributions in a plasma-sprayed magnesia-stabilized zirconia coating on an aluminum piston crown to improve the performance of a diesel engine. Effects of the coating thickness on temperature and thermal stress distributions are investigated, including comparisons with results from an uncoated piston by means of the finite element method. Temperature and thermal stress analyses are performed for various coating thicknesses from 0.2 to 1.6 mm excluding the bond coat layer. Temperature at the coated surface is significantly higher than that of the uncoated piston. It is observed that the coating surface temperature increases with coating thickness by decreasing rate. Increase in the maximum temperature according to the uncoated piston is 64.3% for 1.0 mm thick coating. The higher combustion chamber temperature provided by means of coating results in the better thermal efficiency of the engine. It also provides for a reduction in the substrate surface temperature. The normal stress on the coated surface decreases with increasing coating thickness. Maximum normal stress occurs on the bond coat surface. Its value is approximately two and three times greater than substrate and coating surfaces respectively. Maximum shear stress occurs on the bond coat surface and its magnitude is nearly double that of the substrate surface.

Thermal behavior of glass–ceramic bond coat in a TBC system

Thermal behavior of a glass–ceramic bonded thermal barrier coating (TBC) system was evaluated in terms of oxidation resistance and thermal gradient. It was observed that the weight gain of the glass–ceramic bonded TBC system was significantly lower than that of the conventional TBC system during thermal exposure of 500 h at 1200 °C. Thermal gradient between the top coat and substrate of the present TBC system was found to be 757 °C when the top coat surface temperature was kept at 1200 °C. The present TBC with high oxidation resistance and thermal gradient properties was found to be effective for next generation gas turbine applications.

Effect of grit blasting on the thermal cycling behavior of diffusion aluminide/YSZ TBCs

Abstract Thermal barrier coating system (TBCs) including of chemical vapor deposited NiAl bond coat and electron beam physical vapor deposited Y2O3–stabilized-ZrO2 (YSZ) ceramic coating with and without grit blasting process were investigated. The phase structures, surface and cross-sectional morphologies, cyclic oxidation behaviors of these coatings were studied in detail. Grain boundary ridges form on the surface of aluminide bond coat prior to the deposition of the ceramic coating by EB-PVD, which are shown to be the sites for spallation damage initiation in aluminide/YSZ TBCs. When these ridges are removed, there is no cavity formation and this damage initiation mode is suppressed. Damage initiation and progression occurs at the bond coat to TGO interface leading to a buckling failure behavior. A buckle failure once started may be arrested when it runs into a region of high bond coat to TGO interface toughness. Thus, complete failure requires further loss in toughness of the bond coat to TGO interface with additional cycling. From the result of thermal cycling, an averaged four folds lifetime improvement can be achieved with samples after grit blasting of bond coat surface as compared with those samples existence in ridges on the bond coats’ surface.

Morfo-anatomía, imbibición, viabilidad y germinación de las semillas de <i>Anadenanthera colubrina</i> var. <i>cebil</i> (Fabaceae)

Seed biology is a relevant aspect of tropical forests because it is central to the understanding of processes of plant establishment, succession and natural regeneration. Anadenanthera colubrina var. cebil is a timber tree from South America that produces large seeds with thin weak teguments, which is uncommon among legumes. This study describes the morphology and anatomy of the seed coat, the viability, imbibition, and germination in this species. Seeds used during the essays came from 10 trees that grow naturally in Horco Molle, province of Tucumán, Argentina. Seed morphology was described from a sample of 20 units. The seed coat surface was examined with a scanning electron microscope. Transverse sections of hydrated and non-hydrated seeds were employed to describe the histological structure of the seed coat. Hydration, viability and germination experiments were performed under laboratory controlled conditions; and the experimental design consisted of 10 replicas of 10 seeds each. Viability and germination tests were conducted using freshly fallen seeds and seeds stored for five months. Morphologically the seeds of A. colubrina var. cebil are circular to subcircular, laterally compressed, smooth, bright brown and have a horseshoe fissure line (= pleurogram) on both sides. The seed coat comprises five tissue layers and a double (external and internal) cuticle. The outer cuticle (on the epidermis) is smooth and interrupted by microcracks and pores of variable depth. The epidermis consists of macroesclereids with non-lignified secondary walls. This layer is separated from the underlying ones during seed hydration. The other layers of internal tissues are comprised of osteosclereids, parenchyma, osteosclereids, and macrosclereids. The percentage of viable seeds was 93%, decreasing to 75% in seeds with five months old. Seed mass increased 76% after the first eight hours of hydration. Germination percentage was 75% after 76 hours. Germination of seeds stored for five months decreased to 12%. The results showed that seeds of A. colubrina var. cebil are highly permeable and germinate directly without a dormant period.

Разработка пленкообразующего состава и технологии нанесения полимерной оболочки на таблетки Индотрил

Introduction. In previous researches we grounded expedience of «Indotril» tablets development; formulation and technology of Indotril tablet cores were developed. Received tablet cores should be covered by protective polymeric film with the purpose of unpleasant taste elimination, increase of tablets expiration date. Objective. The aim of our investigation was to develop the film forming composition and technology of polymeric film coating on «Indotril» tablets in pseudo-fluidized layer. Materials and Methods. As “Indotril” tablets cores should be covered by protective polymeric film we performed research designed to select efficient film forming solution. Thus modern filming agents were studied, besides such factors were investigated: concentration of film forming suspension, increase of tablet coat in mass, air temperature under gas distribution grid. Obtained tablets were checked according to pharmacopeia methods. Results and discussion. First we studied tablet compression force influence on main parameters of «Indotril» cores tablets: on crushing strength, abrasion in pseudo-fluidized layer unit and disintegration. Then for further investigation we chose «Indotril» cores tablets with crushing strength near 70 H, abrasion - up to 0,5% and disintegration time - not more than 10 minutes. We performed research to select film forming solution for covering “Indotril” tablets in pseudo-fluidized layer unit. As filming agents we used different samples of hydroxypropyl methylcellulose (HPMC) by Japan company Shin-Etsu Chemical Co and English company Colorcon. Water HPMC solutions were prepared which contained plasticizer (propylene glycol), pigment (titanium IV dioxide) and dye (tartrazine). Coating process of “Indotril” tablets was performed in laboratory pseudo-fluidized layer unit with the air temperature 75oC under gas distribution grid. Variance analysis of experimental data on quality of coat surface showed insignificance as for nature of studied filming agents. Homogeneity in bulk of coated “Indotril” tablets also did not differ significantly as for filming agents’ nature. Divergence in mass of coated tablets did not differ significantly from uncoated ones; it testifies identity of filming process over all tablets surface. Strength of coated “Indotril” tablets as compared with uncoated ones increases in average on 15-20 H. Variance analysis of experimental data concerning tablets disintegration resistance showed that there was no significant difference between studied filming agents. While defining disintegration time statistical significance of filming agents’ nature was determined. Ranking is the following: 6% solution of HPMC Pharmacoat 603 > 5% solution of Opadray II WHITE > 5% solution of HPMC Pharmacoat 606 > 4% solution of HPMC Pharmacoat 615. But the difference between filming agents’ nature is not more than 2 minutes. Opadray II WHITE has been chosen for further study; it comes to the enterprise (“Arterium” Corporation) where the results of investigation are planned to be introduced for the manufacture of other tablet dosage forms. On the next stage of our investigation we defined optimal values of quantitative factors, notably the influence of air temperature under gas distribution grid, concentration of film forming suspension and film thickness on the properties of coated “Indotril” tablets. Conclusion. Influence of filming agent nature on properties of coated tablets «Indotril» was studied, namely on appearance, homogeneity in bulk, mechanical strength, disintegration time . Opadray II WHITE was proposed for coating “Indotril” tablets by protective polymeric coat in pseudo-fluidized layer. Worked out formulation of filming agent solution and technology of its application were included into technological regulation of «Indotril» tablets production.

The influence of laser treatment on thermal shock resistance of plasma-sprayed nanostructured yttria stabilized zirconia thermal barrier coatings

Abstract The main goal of this paper was to evaluate the effects of laser glazing on the microstructure and thermal shock resistance of nanostructured thermal barrier coatings (TBCs). To this end, nanostructured yttria stabilized zirconia (YSZ) top coat and NiCrAlY bond coat were deposited on Inconel 738LC substrate by air plasma spraying (APS). The Nd:YAG pulsed laser was used for laser treatment of top coat surface. The thermal shock behavior of plasma-sprayed and laser-glazed coatings was investigated by quenching the samples in cold water from 1000 °C. The microstructure and phase composition of the coatings were characterized by scanning electron microscopy (SEM) and X-ray diffractometry (XRD). Energy dispersive spectroscopy (EDS) was used to analyze the interface diffusion behavior of the bond coat elements. The results of SEM revealed that the laser glazing process reduced the surface roughness, eliminated the porosity of the surface and produced network cracks perpendicular to the surface. XRD results also indicated that both as-sprayed and laser glazed coatings consisted of non-transformable (T′) phase. Thermal shock test results showed that the lifetimes of the plasma-sprayed TBCs were almost doubled by laser glazing. Continuous network of segmented cracks perpendicular to the surface produced by laser glazing improved the strain accommodation and recognized it as the main enhancement mechanism for TBC life extension.