44 results on '"SCANNING electron microscopes"'
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2. Preparation and Mechanism of Calcium Carbonate Whiskers from DoLOMITE Refined Solution.
- Author
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Hua, Shu‐Yi, Zheng, Qiang, Yu, Feng, Qi, Ting‐Yu, Ma, Ya‐Li, Jia, Song‐Yan, Fan, Tian‐Bo, and Li, Xue
- Subjects
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CALCIUM carbonate , *CRYSTAL whiskers , *DOLOMITE , *X-ray powder diffraction , *SCANNING electron microscopes , *X-ray diffraction , *SIMULATION software - Abstract
The preparation of calcium carbonate whiskers by gas‐liquid contact method using low‐grade dolomite refining solution and CO2 as raw materials has attracted widespread attention. The effects of reaction temperature, Mg2+ concentration and pH value on the morphology, particle size, aspect ratio and crystal form of CaCO3(Calcium carbonate) whiskers are investigated in detail. SEM (Scanning Electron Microscope) and XRD (X‐ray powder diffraction) are combined to analyze the calcium carbonate whiskers. The results demonstrated that under the conditions such as 100 °C, Mg2+ concentration of 0.05 mol L−1 and pH value of 9.5, calcium carbonate whiskers with uniform distribution, aspect ratio of 15–20, and purity of 99.38% can be prepared. Through Material Studios simulation software and critical nucleation energy analysis, it is confirmed that the morphology of calcium carbonate whiskers emerged to be a long hexagonal prism. Mg2+ in the refined solution would adhere to the surface of calcium carbonate during carbonization, inhibit the formation of calcite phase, and promote the growth of face clusters connected by vertex angles between CaCO3 crystals. The initial pH condition determines the solubility of CO32− and the supersaturation of the solution, which in turn affected the formed calcium carbonate crystal form. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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3. Friction and wear properties of polyacrylonitrile‐ and pitch‐based carbon fiber‐reinforced polymer matrix composites containing silicon carbide nanoparticles.
- Author
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Naito, Kimiyoshi, Nakamura, Morimasa, and Matsuoka, Takashi
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CARBON fiber-reinforced plastics , *SILICON carbide , *MECHANICAL wear , *CARBON fibers , *WEAR resistance , *FRICTION , *FIBROUS composites , *SCANNING electron microscopes , *FIBER orientation - Abstract
This study investigated the friction and wear properties of high‐strength polyacrylonitrile (HS‐PAN)‐, high‐modulus polyacrylonitrile (HM‐PAN)‐, and high‐modulus pitch (HM‐pitch)‐based carbon fiber‐reinforced polymer matrix composites (CFRPs) with silicon carbide (SiC) nanoparticles. The fiber orientation of the CFRP specimens was set as 8‐ply unidirectional laminates, denoted as [0]8. Ball‐on‐disk (cyclic) wear testing was accompanied by laser, digital, and scanning electron microscope observations. For the HS‐PAN CFRP, the coefficient of friction and wear resistance were the highest among the HM‐PAN and HM‐pitch CFRPs and wear resistance was improved by the addition of SiC‐nanoparticles. Furthermore, there was no significant enhancement of wear resistance for the SiC‐nanoparticle‐filled and nanoparticle‐unfilled HM‐PAN CFRP. The wear resistance was improved by adding SiC‐nanoparticles for the HM‐pitch CFRP. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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4. Impatiens zhaojueensis (Balsaminaceae) sp. nov. from Sichuan, China.
- Author
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Qiang, Luo, Ying, Yuan, and Hong, Chen
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IMPATIENS , *POLLEN , *SCANNING electron microscopes , *ENGLISH ivy - Abstract
This paper describes and illustrates the morphological traits of Impatiens zhaojueensis Q. Luo (Balsaminaceae), a new species from the Sichuan Province of southwestern China. Using a scanning electron microscope (SEM), the micromorphological characteristics of its pollen grains and seeds are also described. The new species is closely related to Impatiens baishaensis, but it has larger flowers, obround dorsal petals, somewhat clawed lateral united petals, obround or obround‐dolabriform distal lobes and the ornamentation on the pollen grains has wider meshes. [ABSTRACT FROM AUTHOR]
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- 2023
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5. Slow Synthesis Methodology‐Directed Immiscible Octahedral PdxRh1−x Dual‐Atom‐Site Catalysts for Superior Three‐Way Catalytic Activities over Rh.
- Author
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Tan, Zhe, Haneda, Masaaki, Kitagawa, Hiroshi, and Huang, Bo
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CATALYTIC activity , *CATALYSTS , *TRANSMISSION electron microscopes , *X-ray powder diffraction , *RHODIUM catalysts , *SCANNING electron microscopes , *POWDERS - Abstract
This study provided an effective strategy to construct dual‐atom sites by solid–solution alloying. A slow synthesis methodology was established for the solid–solution preparations as dual‐atom‐site catalysts. The atomic‐level homogeneous PdxRh1−x dual‐atom‐site catalysts were successfully synthesized over the whole composition range, as evidenced by X‐ray powder diffraction and scanning transmission electron microscope energy‐dispersive X‐ray spectroscopy mapping measurements. The challenging morphology formation in the immiscible alloys was achieved by an energy‐controlling process as the octahedral Rh‐rich alloys. The Pd0.3Rh0.7 dual‐atom‐site catalyst had unique surface states to activate the key reactants of CO and NO in the complex three‐way catalytic reactions, and it performed significantly better than pure Rh. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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6. Slow Synthesis Methodology‐Directed Immiscible Octahedral PdxRh1−x Dual‐Atom‐Site Catalysts for Superior Three‐Way Catalytic Activities over Rh.
- Author
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Tan, Zhe, Haneda, Masaaki, Kitagawa, Hiroshi, and Huang, Bo
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CATALYTIC activity , *CATALYSTS , *TRANSMISSION electron microscopes , *X-ray powder diffraction , *RHODIUM catalysts , *SCANNING electron microscopes , *POWDERS - Abstract
This study provided an effective strategy to construct dual‐atom sites by solid–solution alloying. A slow synthesis methodology was established for the solid–solution preparations as dual‐atom‐site catalysts. The atomic‐level homogeneous PdxRh1−x dual‐atom‐site catalysts were successfully synthesized over the whole composition range, as evidenced by X‐ray powder diffraction and scanning transmission electron microscope energy‐dispersive X‐ray spectroscopy mapping measurements. The challenging morphology formation in the immiscible alloys was achieved by an energy‐controlling process as the octahedral Rh‐rich alloys. The Pd0.3Rh0.7 dual‐atom‐site catalyst had unique surface states to activate the key reactants of CO and NO in the complex three‐way catalytic reactions, and it performed significantly better than pure Rh. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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7. Growth of Aluminum Doped Zinc Oxide Nanostructure Thin Films by Nonconventional Sol‐Gel Method.
- Author
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Alrefaee, Maher, Singh, Udai Pratap, and Das, Susanta Kumar
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ZINC oxide films , *ZINC oxide thin films , *SOL-gel processes , *THIN films , *CARRIER density , *HALL effect , *SCANNING electron microscopes - Abstract
The present work demonstrates the growth of undoped and Al doped ZnO (AZO) thin films by using nonconventional sol‐gel method. The structural, morphological, optical, and electrical properties of obtained thin films are studied. X‐ray diffraction (XRD) analysis confirms hexagonal wurtzite structures for both undoped and doped thin films. The crystallite size is found between 15 and 30 nm. Scanning electron microscope (SEM) images show that the films have approximately uniform morphologies, consisting in several flower‐like aggregates with nanosized multipetals. From the optical properties, it is found that with the increase in the doping concentration, there is a decrease in the absorption coefficient in the visible wavelength range. It is also noticed that the increase in doping concentration causes an increase in bandgap (Eg) and a decrease in extinction coefficient. Urbach energy decreases with increase in the doping concentration. In the Hall effect study, it is observed that the conductivity and carrier concentration increase sharply with increasing the aluminum quantity. The causes and significance of these observations are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2022
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8. First data about the preimaginal morphology of Austroscaeva occidentalis (Shannon, 1927) and re‐description of larvae and pupae of Dioprosopa clavata (Fabricius, 1794) (Diptera: Syrphidae).
- Author
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Lillo, Inés, Pérez‐Bañón, Celeste, Arcaya, Evelin, Mengual, Ximo, and Rojo, Santos
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PUPAE , *MORPHOLOGY , *DIPTERA , *LARVAE , *SCANNING electron microscopes , *SYRPHIDAE , *BIOLOGICAL rhythms - Abstract
Preimaginal morphology of Austroscaeva occidentalis (Shannon, 1927) is described for the first time, and the morphology of larvae and pupae of Dioprosopa clavata (Fabricius, 1794) is updated based on material obtained from captive rearing of wild females from Argentina and Venezuela, respectively. We describe the morphology of the third instar larva, head skeleton and puparium using optical microscopy, cryo‐scanning and scanning electron microscope. The immature stages of both New World flower fly species are analysed and compared with the known preimaginal morphology of other taxa that belong to the evolutionary lineage of Eupeodes‐Scaeva, where Austroscaeva Láska, Mazánek & Mengual, 2018, and Dioprosopa Hull, 1949, form a Neotropical radiation within, together with the genus Notosyrphus Vockeroth, 1969. Larvae of all members of this lineage have abdominal segments 5 and 6 with the tips of the locomotory prominences facing posteriorly, and the anal segment with a characteristic U‐shaped grasping organ. Two other larval synapomorphies of this group of genera are the presence of metathoracic setae accompanying ventral sensilla, and the abdominal segments 1–7 with an extra lobe on each locomotory prominence. These two last characters cannot be assessed for Macrosyrphus Matsumura, 1917, and Lapposyrphus Dušek & Láska, 1967, based on published information on larval descriptions. Despite a similar colouration pattern of the fully grown larvae, larval morphology of A. occidentalis and D. clavata are quite distinct. The preimaginal morphology of A. occidentalis has a mixture of morphological characters from the taxa Scaeva Fabricius, 1805, Semiscaeva Kuznetzov, 1985, and Dioprosopa. The larvae of D. clavata show several unique diagnostic features, such as the presence of a slightly serrate outline due to the great development of the segmental spines and a pinnate ornamentation of the setae of its dorsal and dorsolateral sensilla. Regarding their biological cycle, the length of the preadult stages of A. occidentalis is almost 5 days longer than the length observed for D. clavata. In addition, new DNA barcodes are provided for A. occidentalis. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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9. Study of the effects of Ni+ ion implantation on morphology, structure, hardness, and electrical conductivity of brass.
- Author
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Shahnawaz, Muhammad
- Subjects
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ELECTRIC conductivity , *ION implantation , *HARDNESS , *BRASS , *SCANNING electron microscopes - Abstract
In this study, nickel ions were implanted in brass at 2.0‐MeV energy doses ranging from 1.9 × 1014, 4.8 × 1014, and 1.0 × 1015 ions cm−2 at room temperature. Formation of micro size particle cluster, crater, void, rust, and flower‐like structure were observed in scanning electron microscope (SEM) micrographs. XRD patterns explain the plane (1 1 1) and plane (2 2 0) under abrupt fluctuations, but in plane (2 0 0), systematic changes occur after ion implantation. Modifications in crystallite size, lattice strain, and dislocation density were discussed. In all the implanted specimens, values of hardness were smaller as compared with the unimplanted one. Precise changes occurred in the value of d‐spacing that produced alteration in electrical conductivity at the initial ion doses. Therefore, electrical conductivity values were changed from 3.980E6 (S/m) to 2.966E7 (S/m). Further increment in the ion dose, electrical conductivity reduced to recover its value. Initial trend of hardness and electrical conductivity was nonlinear, but both tend to recuperate their values in the end. In FT‐IR spectra, three new bands were formed at 1261, 1417, and 1455 cm−1 after ion implantation that was due to change in bonding of brass. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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10. Rheological behavior, electrical conductivity, and morphology of multi‐walled carbon nanotube filled poly(ethylene‐co‐vinyl acetate)/poly(methyl methacrylate) nanocomposites: Effect of nanofiller content.
- Author
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Razavi‐Nouri, Mohammad, Saeedi, Fatemeh, and Ziaee, Farshid
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METHYL methacrylate , *ELECTRIC conductivity , *NANOCOMPOSITE materials , *SCANNING electron microscopes , *YIELD stress , *ACETATES - Abstract
Nanocomposites derived from poly(methyl methacrylate) (PMMA) and poly(ethylene‐co‐vinyl acetate) (EVA) with 30 wt% EVA and 0–10 wt% multi‐walled carbon nanotube (MWCNT) content were prepared. Scanning electron microscope images showed a two‐phase morphology for the unfilled blend in which the EVA droplets were dispersed within the PMMA domain. However, the size of EVA droplets was considerably smaller in the nanocomposites than that of the unfilled blend. The tensile results revealed that the maximum elastic modulus, tensile strength, yield stress, and strain at break were achieved for the nanocomposite containing 5 wt% MWCNT. The electrical conductivity sharply increased for the nanocomposite containing 2.5 wt% MWCNT, in comparison with that of the unfilled blend, beyond which the conductivity was less dependent on the MWCNT content. The rheological characterization showed that the normalized relaxation time increased up to 5 wt% nanofiller and remained reasonably constant for higher amounts of MWCNT. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
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11. The effects of sulfides and sulfur/phosphorus‐containing compounds on coke formation during thermal cracking of light naphtha.
- Author
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Ding, Xudong, Wang, Zhiyuan, Wang, Boyan, and Xing, Zhihong
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COKE (Coal product) , *SULFUR compounds , *SURFACE preparation , *NAPHTHA , *SCANNING electron microscopes , *METAL sulfides , *OXIDE coating - Abstract
In this study, coke deposits during thermal cracking of light naphtha in the presence of sulfur‐ and sulfur/phosphorous‐containing compounds with different addition methods were investigated from the points of morphology and structure. Sulfur/phosphorous‐containing compounds were applied by continuous addition, pretreatment, and pretreatment followed by continuous addition. As for continuous addition, the amount of coke was decreased with increasing the mass concentration of sulfides in short‐term cracking periods. Catalytic coke was inhibited because of passivating the metal by sulfides at the initial stage of coking process. When phosphides were combined with the mixture of sulfides, the coke formation was further decreased as the synergistic effects of adsorption of sulfur and phosphorous onto the metal led to the decreased activity of metal surface. In the case of pretreatment with sulfur/phosphorous, the reduction in coke formation at the initial stage of cracking process was due to the adsorption of S/P‐containing radicals on the oxide film. In further cracking operation, an enrichment of Fe and Ni in the oxide layer from the pretreatment process leads to the appearance of coke filaments in coke layers. The combined addition method, the surface pretreatment with dimethyl disulfide (DMDS)/triphenyl phosphite (TPPI) followed by continuous addition of sulfides/TPPI in the feed, shows the best coking inhibition performance. The inhibition rate is up to 88.8% and 78.5% respectively when the cracking time is 1 and 3 h. The combined application strengthened the coverage of catalytic activity sites by sulfur/phosphorous‐containing radicals. The scanning electron microscope (SEM) results showed that the structural characteristics of coke deposit at the applied conditions were mainly amorphous coke. Variant coke filaments were also observed at the conditions of pretreatment and pretreatment followed by continuous addition. The analyses of Raman spectra indicated that the application methods decreased the graphitization degree of coke deposited and increased the structure defects of the coke matrix. During naphtha cracking, sulfur/phosphorous‐containing compounds reduced dehydrogenation and condensation by which hydrocarbons were degraded to coke. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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12. Morphology of the tongue and laryngeal entrance in the Common pheasant (Phasianus colchicus); a light and scanning electron microscopic study.
- Author
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Mohammad Payam Elyasi, Seyed and Goodarzi, Nader
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PHEASANTS , *SALIVARY glands , *SCANNING electron microscopes , *SCANNING electron microscopy , *MORPHOLOGY , *HYPOGLOSSAL nerve , *GLOTTIS - Abstract
The present work was carried out to describe morphological features of the tongue and laryngeal entrance of the Common pheasantPhasianus colchicus, using light and scanning electron microscopy. The lingual apex was taper‐shaped with a shallow median sulcus. A V‐shaped papillary crest with 15–20 caudally directed conical papillae was located between the radix and corpus linguae. The second row of papillae consisting of three caudolaterally directed conical papillae was arranged caudal to the main papillary crest. The mons laryngealis was equipped caudally with a double‐layer of large conical papillae as pharyngeal crest, and few small conical papillae were seen around the glottis. Scanning electron microscope (SEM) observation showed that the apex linguae and corpus were covered with compact filiform papillae, while the radix linguae were free of papillae. Numerous openings of salivary gland can be seen on the radix linguae and mons laryngealis at higher magnification. On histological sections, all parts of the tongue and mons laryngealis were covered with a keratinised stratified squamous epithelium. The keratinised layer became thinner rostro‐caudally. The simple alveolar salivary glands were distributed in the submucosa from the apex linguae to the radix linguae as well as the mons laryngealis. PAS staining revealed mucin‐secreting activity of this glands. According to the findings, although the tongue and laryngeal entrance of the Common pheasant is characteristics of a galliform bird, it has some features similar to passeriformes and falconiformes. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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13. Structural and optical properties of novel CdSe nanoparticles produced via a facile synthetic route: Studies on the effects of cadmium sources.
- Author
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Kiprotich, Sharon, Dejene, Francis B., and Onani, Martin O.
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OPTICAL properties , *QUANTUM confinement effects , *CADMIUM , *SCANNING electron microscopes , *CADMIUM chloride , *INDUCTIVELY coupled plasma atomic emission spectrometry - Abstract
We report on the successful synthesis of CdSe nanoparticles (NPs) via a facile aqueous approach. Investigation on the effects of various cadmium sources in the precursor solution on the CdSe NPs is discussed. The structural and morphological properties characterized by the X‐ray diffraction (XRD) and scanning electron microscope (SEM) displayed good features of the as‐prepared CdSe NPs. The XRD pattern displayed a pure zinc blende crystal structure for all samples, with the most crystalline sample observed for CdSe NPs prepared using anhydrous cadmium chloride. The estimated crystallite sizes were below 6 nm for all the CdSe NPs samples. Mixed shapes of spherical and nanorods of varying sizes were observed from the SEM images for the as‐prepared NPs prepared using different cadmium sources. The optical studies conducted by photo‐spectroscopy pointed out the CdSe NPs prepared using anhydrous cadmium chloride gave the best optical properties. The emission wavelengths were in the range 565 to 574 nm while the optical band gaps were in the range 2.94 to 3.23 eV for all the as‐prepared CdSe NPs samples. All the samples, however, displayed quantum confinement effects giving room for further fabrication and engineering to suit specific applications in the biological field. The obtained results demonstrated that aqueous phase synthetic route employed in this study could be successfully adopted for production of high‐quality CdSe NPs because of its facile and inexpensive nature. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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14. First record of the subfamily Psallopinae (Heteroptera: Miridae) from Australia and discussion of its systematic position and diagnostic characters.
- Author
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Namyatova, Anna A. and Cassis, Gerasimos
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MIRIDAE , *SPECIES distribution , *SCANNING electron microscopes , *DISSECTING microscopes - Abstract
Psallopinae are the smallest subfamily within the heteropteran family Miridae, including only two extant genera and 18 species. This group is widely distributed in the Old World but previously has never been recorded from Australia. In this work, Psallopinae is recorded for the first time from the Australian continent, with the description of three new species of Psallops Usinger. A comparison of the Australian taxa with extralimital species is provided. The distribution of Psallops in Australia, the morphology of the genus and the systematic position of Psallopinae within Miridae are discussed. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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15. Discovery of the subfamily Lycorininae Cushman & Rohwer, 1920 (Hymenoptera: Ichneumonidae) from Indonesia, based on Lycorina longicauda Shimizu, sp. nov., with a key to the Oriental Lycorina species.
- Author
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Shimizu, So and Ogawa, Ryo
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ICHNEUMONIDAE , *SPECIES distribution , *PHYLOGENY , *MORPHOLOGY , *SCANNING electron microscopes - Abstract
The subfamily Lycorininae Cushman & Rohwer is discovered from Indonesia based on a single new species, Lycorina longicauda Shimizu, sp. nov., which can be easily distinguished from any other Lycorina species by its longer ovipositor sheath and colour pattern. We also provide a key to the five species of Lycorina known from the Oriental region. [ABSTRACT FROM AUTHOR]
- Published
- 2019
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16. Characterization of MnS Particles in Heavy Rail Steels Using Different Methods.
- Author
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Zhang, Xuewei, Zhang, Lifeng, Yang, Wen, and Dong, Yuanchi
- Subjects
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MANGANOUS sulfide , *CONTINUOUS casting , *IRON sulfides , *SCANNING electron microscopes , *INCLUSIONS in steel - Abstract
Characterization of the MnS particles in continuous casting (CC) blooms and rolled rails of U75V steel using the methods of traditional two-dimensional (2D) microscope observation, three-dimensional (3D) micro-CT detection, and electrolytic extraction is performed. MnS particles from the surface to the interior, inside of columnar dendritic zone, and the equiaxed zone of the CC bloom are discussed. The morphology of MnS changes from elliptical and spherical near the surface of bloom to strip-like, petal-like, polyhedral, and irregular in the center of bloom gradually. The size of both pure MnS particles and complex inclusions which consist of a MnS outer layer and an oxide core increase from the edge to the center of bloom. However, MnS is elongated along the rolling direction during rolling process. The morphology of the cross section of the elongated MnS particles presents as globular and flaggy shape in the head and bottom of rail, and spindle shape in the waist of rail. The precipitation of MnS particles is studied on the basis of thermodynamics, the calculating results show that MnS particles are generated towards the end of solidification (solid fraction fS = 0.94), the amount of MnS particles are affected by the initial concentration of Mn and S in molten steel during solidification. [ABSTRACT FROM AUTHOR]
- Published
- 2017
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17. Mechanism of the formation of copper-containing fractal-like crystallites in metal-organic thin films: Shape simulation and XANES analysis.
- Author
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Yalovega, Galina, Myasoedova, Tatiana, Funik, Anton, Plugotarenko, Nina, Brzhezinskaya, Maria, and Bahmatskaya, Alexandra
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COPPER , *THIN films , *MORPHOLOGY , *SCANNING electron microscopes , *X-ray absorption near edge structure - Abstract
Copper-containing thin films were synthesized by a citrate sol-gel method using ethylene glycol. The evolution of the shape and local atomic structure of the copper-containing fractal crystallites at different stages of growth was investigated by the combination of experimental and theoretical techniques. A surface morphological study of the deposited film samples was carried out using SEM. It revealed the evolution of the crystallite structures as a function of annealing temperature. To describe this mechanism diffusion-limiting aggregation and cluster-cluster models were used. X-ray absorption spectroscopy (XANES) was applied to show the dynamics of the local atomic structure of Cu ion and the copper oxidation state at different stages of crystallites formation. It was found that at temperatures up to 250 °C the Cu2Cl(OH)3 (atacamite phase) and chelate complex are formed. With temperature increases changes in the local atomic structure as well as in morphology take place and at 500 °C CuO formed. As a result of these processes, the fractal organization of the other level was observed. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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18. Plasmonic effects and the morphology changes on the active material P3HT:PCBM used in polymer solar cells using Raman spectroscopy.
- Author
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Yang, Yuzhao, Sun, Lu, Ou, Jiemei, He, Yiting, Lin, Xiaofeng, Yuan, Zhongke, Lin, Wensheng, Hong, Wei, Yu, Dingshan, Chen, Xudong, and Qiu, Zhiren
- Subjects
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NANOWIRES , *RAMAN microscopy , *SCANNING electron microscopes , *SPECTROMETRY , *SPECTRUM analysis , *RAMAN spectroscopy - Abstract
There is no consensus yet that the enhancement effects of plasmonic device are predominantly caused by plasmonic effects or induced morphology changes in the optoelectronic `materials. Herein, we present a detailed Raman characterization of a typical organic P3HT:PCBM system comprising silver nanowires (Ag NWs) with different size, which can simultaneously study the plasmonic effects and the morphology changes. The direct comparison of the Raman spectra of non-annealed and annealed samples indicates that the morphology of plasmonic samples has changed before annealing and the morphology of plasmonic samples and reference sample after annealing is not distinguishable. This indicates that the interaction between P3HT and Ag NWs with different size can be explained by plasmonic effects after annealing. Moreover, in-situ Raman spectroscopy is used to study the morphology changes in plasmonic samples with different diameters of Ag NWs during heating process. This method can distinguish the plasmonic effects and morphology changes of plasmonic device. Copyright © 2016 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2016
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19. Morphological, physicochemical, and antioxidant profile of noncommercial banana cultivars.
- Author
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Anyasi, Tonna A., Jideani, Afam I.O., and Mchau, Godwin A.
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ANTIOXIDANTS , *BANANA varieties , *FRUIT morphology , *POLYPHENOLS , *SCANNING electron microscopes , *ANALYSIS of variance - Abstract
Banana cultivars--Luvhele ( Musa ABB), Mabonde ( Musa AAA), and Muomva-red ( Musa balbisiana) --were characterized for morphological, physicochemical, and antioxidant properties. All three cultivars varied significantly ( P < 0.05) in their morphology, pH, titratable acidity and total soluble solids with no significant difference in their ash content. Individual cultivars showed variations in flour starch granule when observed using a scanning electron microscope. Characterization of cultivars for total polyphenols ( TPs) and antioxidant activity upon pretreatment with ascorbic, citric, and lactic acid shows that the 1,1-diphenyl-2-picrylhydrazyl ( DPPH) radical scavenging assay of samples varied significantly as Muomva-red cultivar (1.02 ± 0.01 mg GA/g) expressed the highest DPPH activity at lactic acid concentration of 20 g/L. Total polyphenol content was also highest for Muomva-red [1091.76 ± 122.81 mg GAE/100 g (d.w.)]. The high amount of TPs present in these cultivars make them suitable source of bio-nutrients with great medicinal and health functions. [ABSTRACT FROM AUTHOR]
- Published
- 2015
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20. Morphology of craters generated by hypervelocity impacts of micron-sized polypyrrole-coated olivine particles.
- Author
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Li, Y. W., Bugiel, S., Trieloff, M., Hillier, Jon K., Postberg, F., Price, M. C., Shu, A., Fiege, K., Fielding, L. A., Armes, S. P., Wu, Y. Y., Grün, E., and Srama, R.
- Subjects
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LOWS (Meteorology) , *MORPHOLOGY , *COSMIC dust , *METALLIC surfaces , *SCANNING electron microscopes , *BATHYMETRY - Abstract
To understand the process of cosmic dust particle impacts and translate crater morphology on smoothed metallic surfaces to dust properties, correct calibration of the experimental impact data is needed. This article presents the results of studies of crater morphology generated by impacts using micron-sized polypyrrole ( PPy)-coated olivine particles. The particles were accelerated by an electrostatic dust accelerator to high speeds before they impacted onto polished aluminum targets. The projectile diameter and velocity ranges were 0.3-1.2 μm and 3-7 km s−1. After impact, stereopair images of the craters were taken using scanning electron microscope and 3-D reconstructions made to provide diameter and depth measurements. In this study, not just the dimensions of crater diameters and depths, but also the shape and dimensions of crater lips were analyzed. The craters created by the coated olivine projectiles are shown to have complicated shapes believed to be due to the nonspherical shape of the projectiles. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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21. Comparative description of the hairy structures in two endemic Velia species ( Insecta: Hemiptera: Heteroptera: Veliidae): V. currens ( Fabricius, 1794) and V. gridellii Tamanini, 1947.
- Author
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Cianferoni, Fabio and Santini, Giacomo
- Subjects
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VELIA , *SCANNING electron microscopes , *HEMIPTERA , *SEMIAQUATIC bugs , *INSECT morphology , *HAIR - Abstract
This study provides the first description, based on SEM imagery, of the hairy structures related to life on the water surface of two Alpine- Apenninic species belonging to the genus Velia: V. currens ( Fabricius, 1794) and V. gridellii Tamanini, 1947. In general, no relevant differences in the organization and form of these structures were found between the two species. Similarly, few differences were observed between males and females, and in comparison with the only congeneric with hairy structures thus far described, V. caprai Tamanini, 1947, confirming a substantial homogeneity within the subgenus Plesiovelia. The discovery of a double layer of microtrichia in both our species allowed us to detect them even in V. caprai, for which only a single layer was previously described. Finally, the presence of a structure corresponding to the male grasping comb was discovered in females of V. gridellii and is reported for the first time in the genus and in the Old World Veliinae. A similar structure was not identified in V. currens. This difference may be relevant for better understanding the relationships among species belonging to this genus. [ABSTRACT FROM AUTHOR]
- Published
- 2014
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22. SEM observation of the live morphology of human red blood cells under high vacuum conditions using a novel RTIL.
- Author
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Hyono, Atsushi, Yonezawa, Tetsu, Kawai, Koji, Abe, Shigeaki, Fujihara, Mitsuhiro, Azuma, Hiroshi, and Wakamoto, Shinobu
- Subjects
- *
SCANNING electron microscopes , *MORPHOLOGY , *ERYTHROCYTES , *VACUUM , *HYDROPHILIC compounds - Abstract
In this study, we succeed in visualizing a 'living' morphology of red blood cells (RBCs) by a rapid and simple scanning electron microscope (SEM) pretreatment using a hydrophilic room temperature ionic liquid (RTIL) with asymmetrical structure. The conventional pretreatment induces size shrinkage of the cells, and the diameter observed in an SEM (less than 6 µm) was smaller than that in an optical microscope (8 µm). Though RBCs are well-known to be easily deformed with the environmental conditions, the cells did not show the deformation when they were pretreated with our RTILs. Since the chemical structure of our RTIL resembles a 'choline', which is a typical bioactive material, and has biocompatibilities, they may make it avoid from the deformation of RBCs. In fact, only immersing RBCs, our novel RTIL can provide a clear SEM image without size shrinkage and deformation. Interestingly, the obtained SEM image shows 8 µm in the diameter, almost same size as that in optical microscope. Therefore, this method is expected for novel SEM pretreatment for various biological samples observation as 'living' matter. Copyright © 2014 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
23. Spectroscopic ellipsometry investigations of porous SiO2 films prepared by glancing angle deposition.
- Author
-
Yang, Shenghong and Zhang, Yueli
- Subjects
- *
ELLIPSOMETRY , *POROUS materials , *MORPHOLOGY , *THIN films , *SCANNING electron microscopes - Abstract
We present the optical and the structural properties of porous SiO2 films fabricated by using a glancing angle deposition technique. The influence of the glancing angle on the pseudorefractive index of porous SiO2 films was studied by spectroscopic ellipsometry in the UV-visible region. The relationships among the pseudorefractive index, the porosity, and the glancing angle are determined. The results show that the pseudorefractive index decreases and the porosity increases with the increase of glancing angle. The minimum pseudorefractive index is found to be 1.11 at 532 nm for the porous SiO2 film deposited at a glancing angle of 87°. The structural and surface morphology of these samples was also investigated by using a scanning electron microscope. The results indicate that the as-deposited SiO2 thin films are porous with a tilted-columnar structure and low pseudorefractive index. Copyright © 2013 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
24. The effect of Bi addition on the microstructure and tensile properties of cast Al-15%Mg2Si composite.
- Author
-
Akrami, A., Emamy, M., and Mousavian, H.
- Subjects
- *
BISMUTH , *MICROSTRUCTURE , *CRYSTAL morphology , *TENSILE tests , *SCANNING electron microscopes - Abstract
In the current research, the influence of different concentrations of Bi (0.01-0.3 wt.%) on the microstructure and tensile properties of Al-15 wt.% Mg2Si in-situ metal matrix composite (MMC) has been investigated. It was found that 0.03 wt.% Bi changes the primary Mg2Si shape from large to irregular or dendritic to polyhedral shape. The average particle size of Mg2Si also decreases from 65 μm to 20 μm by adding 0.03% Bi. Microstructural observations by scanning electron microscope (SEM) also depicted that the morphology of the eutectic Mg2Si phase alters from flake-like to fine fiber or dot like. Further investigations on tensile testing revealed that the optimum amount of Bi level is 0.03% for improving both ultimate tensile test (UTS) and elongation values. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
25. Organic photovoltaics: Challenges and opportunities.
- Author
-
Gaudiana, Russell
- Subjects
- *
PHOTOVOLTAIC power generation , *COST effectiveness , *SOLAR radiation , *SILICON solar cells , *SCANNING electron microscopes , *HETEROJUNCTIONS - Abstract
Challenges remain overcome on the road to manufacturing stable, high-performance organic photovoltaic modules in high volume at low cost. The major challenges are centered on stability to high-intensity solar radiation, which represents one of the many accelerated aging tests, and module efficiency. Several of the underlying problems for both of these will be discussed in the text, and some will be addressed in the following papers. © 2012 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2012 [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
26. TAXONOMIC REVISION OF THE DINOFLAGELLATE AMPHIDOMA CAUDATA: TRANSFER TO THE GENUS AZADINIUM (DINOPHYCEAE) AND PROPOSAL OF TWO VARIETIES, BASED ON MORPHOLOGICAL AND MOLECULAR PHYLOGENETIC ANALYSES1 TAXONOMIC REVISION OF THE DINOFLAGELLATE AMPHIDOMA CAUDATA: TRANSFER TO THE GENUS AZADINIUM (DINOPHYCEAE) AND PROPOSAL OF TWO VARIETIES, BASED ON MORPHOLOGICAL AND MOLECULAR PHYLOGENETIC ANALYSES
- Author
-
Nézan, Elisabeth, Tillmann, Urban, Bilien, Gwenae¨ l, Boulben, Sylviane, Chèze, Karine, Zentz, Frédéric, Salas, Rafael, and Chomérat, Nicolas
- Subjects
- *
ALGAL evolution , *DINOFLAGELLATES , *ALGAE , *PHYLOGENY , *SCANNING electron microscopes , *CLADISTIC analysis , *RIBOSOMAL RNA , *CLUSTER analysis (Statistics) , *CULTIVARS - Abstract
The systematic position of Amphidoma caudata Halldal within the genus Amphidoma has remained uncertain as a result of its plate formula and the absence of molecular phylogenetic data. Also, this thecate dinoflagellate taxon has been used to designate two distinct morphotypes. The present study aims to clarify the generic affiliation of Amphidoma caudata and the taxonomic value of two different morphotypes M1 and M2. The new examination of the plate formula using SEM showed that it was the same for both morphotypes and that it corresponded to the tabulation of the recent erected genus Azadinium Elbrächter et Tillmann. Morphometric analysis, using cell size, length of apical projection in conjunction with the cell length, and the ratio of horn and spine showed that M1 and M2 formed two distinct groups. These results were supported by a molecular approach, revealing notable differences in the sequences of LSU rDNA and ITS region between these two morphotypes. Phylogenetic analyses inferred either from LSU and combined SSU, ITS region and COI data positioned M1 and M2 in a sister cluster of Azadinium species while Amphidoma languida Tillmann, Salas et Elbrächter, the only species of Amphidoma for which sequence data were available, was situated in a basal position of the Azadinium clade. Thus, we propose the transfer of Amphidoma caudata to the genus Azadinium and, consequently, the rehabilitation of the original tabulation of the genus Amphidoma Stein. To discriminate the two morphotypes, we propose a rank of variety with the following designations: Azadinium caudatum var. caudatum and Azadinium caudatum var. margalefii. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
27. Lagrange time delay estimation for scanning electron microscope image magnification.
- Author
-
SIM, K.-S., THONG, L. W., TING, H. Y., and TSO, C. P.
- Subjects
- *
INTERPOLATION , *SCANNING electron microscopes , *ELECTRON microscopes , *MORPHOLOGY , *COMPARATIVE anatomy - Abstract
Interpolation techniques that are used for image magnification to obtain more useful details of the surface such as morphology and mechanical contrast usually rely on the signal information distributed around edges and areas of sharp changes and these signal information can also be used to predict missing details from the sample image. However, many of these interpolation methods tend to smooth or blur out image details around the edges. In the present study, a Lagrange time delay estimation interpolator method is proposed and this method only requires a small filter order and has no noticeable estimation bias. Comparing results with the original scanning electron microscope magnification and results of various other interpolation methods, the Lagrange time delay estimation interpolator is found to be more efficient, more robust and easier to execute. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
28. Microstructure and Electromagnetic Properties of SrTiO3/Ni0.8Zn0.2Fe2O4 Composites by Hybrid Process.
- Author
-
Haibo Yang, Hong Wang, Feng Xiang, and Xi Yao
- Subjects
- *
MICROSTRUCTURE , *ELECTROMAGNETISM , *MORPHOLOGY , *DIELECTRICS , *ELECTROMAGNETIC interference , *ANTENNAS (Electronics) , *SCANNING electron microscopes , *X-ray diffraction - Abstract
High permittivity and low-loss SrTiO3/Ni0.8Zn0.2Fe2O4 (STO/NZO) composites with concrete-like morphology were prepared through hybrid processing route. The dielectric properties in the low-frequency range (100 Hz–1 MHz) follow the rule of Maxwell–Wagner interfacial polarization. The dielectric and magnetic properties in the high-frequency range (10 MHz–1 GHz) exhibit a well integration of dielectric and magnetic properties in the composites with low dielectric and magnetic losses. The STO/NZO composites show good dielectric properties and magnetic properties with low loss in high-frequency to microwave-frequency range. The results show that this kind of magnetic–dielectric composites can be used in high-frequency communications for the capacitor–inductor integrating devices such as electromagnetic interference filters and antennas. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
29. Pollen Morphology of Tundra Shrubs and Submarginal Plants from Barrow, Alaska.
- Author
-
Ling-Yu Tang, Xiao-Ping Zhang, Jian-Wen Shao, Zhong-Ze Zhou, and Qing-Song Zhang
- Subjects
- *
PLANT morphology , *TUNDRA plants , *POLLEN , *SCANNING electron microscopes , *MORPHOLOGY - Abstract
Investigation of plant morphological features, pollen, and habitat have been made for two shrub species from Barrow, Alaska, namely Dryas integrifolia M. Vahl and Salix rotundifolia Trautv., both of which are endemic to the Arctic floristic area. The former species has small lanceolate or plate leaves, whereas the latter has rounded leaves with distinct veins, rich in vitamin C. Both have dwarf and sprawling habits. Pollen studies showed that the pollen grains of the two species are spheroidal to sub-spheroidal or prolate. The type of aperture was tricolporate; pollen size 26.3–31.3 μm; ornamentation finely reticulate under a light microscope (LM) and striate-reticulate under a scanning electron microscope (SEM) for D. integrafolia and finely reticulate under the LM and SEM for S. rotundifolia. Comparisons were made between the pollen from the same species from Arctic collections with those from China and Japan. Investigation of pollen morphology of tundra plants can provide significant data for comparative studies of fossil pollen and for the reconstruction of paleovegetation and paleoclimate in the Barrow area. (Managing editor: Ya-Qin Han) [ABSTRACT FROM AUTHOR]
- Published
- 2006
- Full Text
- View/download PDF
30. Effect of chemical composition of Ni-Cr dental casting alloys on the bonding characterization between porcelain and metal.
- Author
-
HUANG, H.‐H., LIN, M.‐C., LEE, T.‐H., YANG, H.‐W., CHEN, F.‐l., WU, S.‐C., and HSU, C.‐C.
- Subjects
- *
DENTAL casting , *ALLOYS , *PORCELAIN , *SCANNING electron microscopes , *MORPHOLOGY , *SPECTROMETERS , *BONE fractures - Abstract
The purpose of this study was to investigate the influence of chemical composition of Ni-Cr dental casting alloys on the bonding behaviour between porcelain and metal. A three-point bending test was used to measure the fracture load of alloy after porcelain firing. A scanning electron microscope, accompanied by an energy dispersion spectrometer, was used to analyse the morphology and chemical composition of the fracture surface. An X-ray photoelectron spectrometer and glow discharge spectrometer were used to identify the structure and cross-sectional chemical composition, respectively, of oxide layers on Ni-Cr alloys after heat treatment at 990 °C for 5 min. Results showed that the oxide layers formed on all Ni-Cr alloys contained mainly Cr2O3, NiO, and trace MoO3. The Ni-Cr alloy with a higher Cr content had a thicker oxide layer, as well as a weaker bonding behaviour of porcelain/metal interface. The presence of Al (as Al2O3) and Be (as BeO) on the oxide layer suppressed the growth of the oxide layer, leading to a better porcelain/metal bonding behaviour. However, the presence of a small amount of Ti (as TiO2) on the oxide layer did not have any influence on the bonding behaviour. The fracture propagated along the interface between the opaque porcelain and metal, and exhibited an adhesive type of fracture morphology. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
31. High-concentrated carbamide peroxide bleaching agents effects on enamel surface.
- Author
-
Cavalli, V., Arrais, C. A. G., Giannini, M., and Ambrosano, G. M. B.
- Subjects
- *
TOOTH whitening , *COLLOIDS , *PEROXIDES , *STAINS & staining (Microscopy) , *MORPHOLOGY , *SCANNING electron microscopes , *DENTISTRY - Abstract
Concern has been expressed regarding the adverse effects of peroxide-containing tooth bleaching agents on enamel surface. This study examined enamel average surface roughness before (baseline) and after an in-office bleaching protocol and investigated the influence of high concentrations of carbamide peroxide gels on its surface staining and morphology. Flat enamel surfaces were submitted to 35 and 37% carbamide peroxide or to no bleaching treatment ( n = 10) and evaluated with a profilometer. Eight specimens from each group were randomly selected and immersed in a 2% methylene blue solution. Afterwards, specimens were ground into powder and prepared for the spectrophotometric analysis. Two remained specimens of each group were examined using a scanning electron microscope. Data were subjected to analysis of variance and Tukey test ( P > 0·05). Baseline roughness average was statistically similar for all groups, however, 35% carbamide peroxide produced the roughest enamel surfaces. Different concentrations of carbamide peroxide produced similar staining means and enamel surface morphological alterations. [ABSTRACT FROM AUTHOR]
- Published
- 2004
- Full Text
- View/download PDF
32. Morphological study of the marine planktonic diatom Chaetoceros okamurai (Chaetocerotales, Bacillariophyceae) from the Gulf of Mexico.
- Author
-
Hernández-Becerril, David U.
- Subjects
- *
MARINE plankton , *SCANNING electron microscopes , *MORPHOLOGY - Abstract
Examines the morphology of the marine planktonic diatom Chaetoceros okamurai from the Gulf of Mexico. Use of light scanning electron microscopy in studying the morphology of the species; Characteristics of the species; Detail of the complete intercalary cell of C. okamurai.
- Published
- 1998
- Full Text
- View/download PDF
33. LEAF MICROMORPHOLOGY OF SEA CLIFF AND INLAND PLANTS OF AGROSTIS STOLONIFERA L., DACTYLUS GLOMERATA L. AND HOLCUS LANATUS L.
- Author
-
McNeilly, T., Ashraf, M., and Veltkamp, C.
- Subjects
- *
SCANNING electron microscopes , *MORPHOLOGY , *CREEPING bentgrass , *EPIDERMIS , *ORCHARD grass , *GRASSES - Abstract
Scanning electron microscope examination of the morphology of adaxial and abaxial leaf surfaces of salt spray-tolerant and normal plants of Agrostis stolonifera L., Dactylis glomerata L. and Holcus lanatus L. was carried out. Differences were found in degree and types of waxiness of epidermal cells, number and size of macro-hairs and prickles, epidermal cell lengths and extent to which stomata were sunken. These differences were consistent with a reduction of the wettability, and hence salt spray damage, to adaxial leaf surfaces. Abaxial leaf surface differences were much less pronounced. [ABSTRACT FROM AUTHOR]
- Published
- 1987
- Full Text
- View/download PDF
34. Morphology of the second- and third-instar larvae of Dermatobia hominis by scanning electron microscopy.
- Author
-
DE FILIPPIS, THELMA, LEITE, and LEITE
- Subjects
- *
DERMATOBIA hominis , *LARVAE , *SCANNING electron microscopes , *MORPHOLOGY - Abstract
Larvae of Dermatobia hominis 10–27 days old were collected from experimentally infected rats and their morphology was studied by scanning electron microscopy. The moult from the second to third instar occurs at 18 days, with emergence from the host at 30 days post-infection. The second-instar larvae bear on the pseudocephalon, antennae (coeloconic sensilla), and coeloconic and basicoconic sensilla on the maxillary sensory complex. The thoracic segments bear small backwardly-directed spines anteriorly and ventral trichoid and campaniform sensilla. The first four abdominal segments have small and large backwardly-directed spines that are absent on segments five and six. The seventh and eighth abdominal segments have medium-sized forwardly-directed spines. Abdominal segments are encircled by campaniform sensilla. The terminal end of the eighth abdominal segment bears the anus, prominent anal lobes and two spiracular openings on each spiracular plate. Spiracular plates show a radial sun ray pattern. The rear abdomen also bears an ecdysal aperture, several pores and eight coeloconic sensilla. Although there are slight morphological differences, the spines (predominantly flat and thorn-like) and sensilla (campaniform and coeloconic) of the third-instar larvae show a similar arrangement to that of second-instar larvae. Thoracic trichoid sensilla are not seen in third-instar larvae. A perispiracular gland aperture is situated above each posterior spiracular opening. These morphological features are compared with those of other cuterebrid larvae. [ABSTRACT FROM AUTHOR]
- Published
- 1998
- Full Text
- View/download PDF
35. Correlative light microscopic and scanning electron microscopic study of completely and incompletely orthokeratinized rat oral epithelium.
- Author
-
Philipsen, Hans P., Cleaton-Jones, Peter, and Fisker, Anders V.
- Subjects
- *
CELL membranes , *ORAL mucosa , *MICROSCOPES , *SCANNING electron microscopes , *MORPHOLOGY , *EPITHELIUM - Abstract
Using light microscope (LM) and scanning electron microscope(SEM) a study of the surface morphology of rat oral epithelium was undertaken. A good correlation was found between the LM and SEM findings in the demonstration of the characteristic differences in surface structure between completely and incompletely orthokeratinized areas of the rat oral epithelium. Completely keratinized epithelium (hard palate and attached gingiva) shows a surface layer of orderly arranged, closely approximated and overlapping cells. The individual cell surface shows a honeycomb pattern of interconnecting ridges surrounding depressions or micropits. Incompletely keratinized epithelium (buccal mucosa, alveolar sulci, gingival crest and interpapillary area of the dorsum of the tongue) shows a very uneven, corrugated surface layer. There is considerable loss of cell cohesion with the formation of wide intercellular clefts. The individual cell surface is characterized by microplications of irregular size and arrangement. The findings of the present investigation are discussed in the light of an idea previously put forward by the authors that a correlation exists between surface morphology of the keratinized rat oral mucosa and colonization and penetration of Candida organisms in experimental candidosis. [ABSTRACT FROM AUTHOR]
- Published
- 1982
- Full Text
- View/download PDF
36. Tinea Versicolor: A Scanning Electron Microscopic View.
- Author
-
Marinaro, R. E., Gershenbaum, M. R., Roisen, F. J., and Papa, C. M.
- Subjects
- *
SCANNING electron microscopes , *SAMPLING (Process) , *MORPHOLOGY , *BIOPSY , *DISEASES , *INFECTION - Abstract
Tinea versicolor (TV) infections were studied in the scanning electron microscope utilizing several different sampling and preparatory techniques. Scalpel scrapings provided information only on the morphology of individual spores and hyphae, while biopsies and cyanoacrylate adhesive slides demonstrated the topography of the disease as well as providing information on how the infection spreads and recurs. Critical point drying was necessary to maintain the fine ultrastructure previously described. The deep follicular location of the spores seen in this study probably explains the tendency for TV to recur. The follicular packing was specific, since the eccrine pores seem to be exempt from the infection. [ABSTRACT FROM AUTHOR]
- Published
- 1978
- Full Text
- View/download PDF
37. Scanning electron microscopic studies on <em>Cyclotella obliquata</em> Ii et YangI).
- Author
-
Yu-zao Qi and Jing-rong Yang
- Subjects
- *
ALGAE , *PHYCOLOGY , *PHYTOPLANKTON , *AQUATIC resources , *SCANNING electron microscopes - Abstract
Reports on the result of the scanning electron microscopic studies on Cyclotella obliquata collected from Sichuan Province, China. Occurrence of the species in early Pleistocene deposits; Material and methods used; Description of the external and internal structure of C. obliquata; Difference of C. obliquata Qi et Yang from Cyclotella bodanical comta.
- Published
- 1987
38. Ultrastructure of hypersensitive and non-sensitive dentine: A study on replica models.
- Author
-
Rimondini, Lia, Baroni, Chiara, and Carrassi, Antonio
- Subjects
- *
DENTISTRY , *DENTIN , *OPTICAL instruments , *SCANNING electron microscopes , *ALLERGIES , *MORPHOLOGY - Abstract
Patients with cervical dentine exposures do not always complain of dentine hypersensitivity. The identification of morphological features connected to symptoms is important for both prevention and management of dentine hypersensitivity. The aim of the study was to determine the relationship between the dentine ultrastructure and clinical symptoms in patients with cervical dentine exposures. Replica models for a total of 28 teeth (from 10 patients) with cervical non caroius lesions and dentine exposures were obtained before and after acid etching. The replica models were studied blindly in the scanning electron microscope (SEM). 12 of these were classified clinically as hypersensitive and 16 as non-sensitive. Because of the morphological heterogeneity of all specimens. A grid was used to isolate smaller, more homogeneous areas. 120 (75 non-sensitive and 45 hypersensitive areas grid areas randomly selected from the 28 dentine surfaces were analyzed. The presence and morphology (amorphous or crystalline) of smear layers and the density and diameter of dentine tubules were recorded. The χ² test was used for statistical analysis. In unetched specimens, the surfaces classified as non-sensitive were frequently coated by an amorphous smear layer (88.0%) and occasionally by a crystalline smear layer (2.7%). Only a few and narrow tubules were observed (9.3%). On the other hand, the unetched specimens of the hypersensitive dentine exhibited less frequently (31.3%) an amorphous smear layer. The presence of crystalline smear layer 33.3%), many and wider patent tubules and, sometimes, loss of intertubular dentine manifested as grooves between tubules, were observed 35.6%). The differences were significant (p<.001). In hypersensitive dentine, the acid etching always removed the smear layer whereas removal in non-sensitive dentine was partial or absent. These morphological findings underline the role of smear layer in reducing permeability of dentine in patients with dentine sensitivity. [ABSTRACT FROM AUTHOR]
- Published
- 1995
- Full Text
- View/download PDF
39. Morphology of the root canal wall and arrangement of underlying dentinal tubules.
- Author
-
Wakabayashi, H., Matstumoto, K., Nakamura, Y., and Shirasuka, T.
- Subjects
- *
ELECTRON microscopes , *SCANNING electron microscopes , *DENTIN , *DENTAL pulp cavities , *MICROSCOPY , *MORPHOLOGY - Abstract
The morphology of the root canal wall and the arrangement of the dentinal tubules underlying it were investigated in this study. Fifty clinically sound single-rooted human teeth were cut for longitudinal and transverse sections. After dissolving the organic components and removing the smear layer, the specimens were prepared for scanning electron microscopy. In the upper root level, semiglobular calcospherites were present on the canal wall and a convergent arrangement of the dentinal tubules was found on the transverse sections. At the mid-root level, an irregular area of calcification comprising of compressed calcospherites began to appear on the proximal wall and increased towards the apex. The transverse sections showed the crowding and convoluted arrangement of the dentinal tubules near the canal wall, in the proximal area. A correlation was noticed between the irregular calcification on the wall and a convoluted tubular arrangement below the wall. These features were common in most of the specimens. This irregular secondary dentine does not appear to be pathological but physiological: associated with the normal ageing of the root. [ABSTRACT FROM AUTHOR]
- Published
- 1993
- Full Text
- View/download PDF
40. Bruxism and its effect on the teeth.
- Author
-
Xhonga, Frida A.
- Subjects
- *
TEETH abnormalities , *BRUXISM , *MORPHOLOGY , *SCANNING electron microscopes , *ORAL habits , *DENTISTRY - Abstract
This study presents the progress of tooth wear and the change in structural morphology on individual teeth of bruxist subjects, compared with non-bruxers. From the results of this investigation it can be concluded that the tooth wear progressed faster in bruxers than in non-bruxers, Scanning electron microscope investigations revealed in 10 teeth the same pattern of deep grooves and striations on the wear-facets of active bruxers. [ABSTRACT FROM AUTHOR]
- Published
- 1977
- Full Text
- View/download PDF
41. Sensory Organs on the Antennae of Micropterix calthella L. (Lepidoptera, Micropterigidae).
- Author
-
Faucheux, Michel J.
- Subjects
- *
MOTHS , *SENSORY receptors , *MORPHOLOGY , *SCANNING electron microscopes , *LEPIDOPTERA , *ELECTRON microscopes - Abstract
Antennal sensilla of Micropterix calthella were studied with the scanning electron microscope to determine their morphological types, relative abundance, distribution, location and possible functions. Of the 12 types occurring in both male and female moths, seven are found in most higher Lepidoptera: sensilla trichodea, multiporous s. basiconica, s. coeloconica, s. styloconica, s. chaetica, s. campaniformia and Bohm's bristles. Two types (uniporous s. basiconica and cupuliform organs) are found only in a few families. Three structures are peculiar to Micropterix: ascoid sensilla, multiporous s. placodea and circular organs. All types of sensilla have characteristic distribution and location pattern similar in both sexes. [ABSTRACT FROM AUTHOR]
- Published
- 1997
- Full Text
- View/download PDF
42. Morphology of α′H-Ca2SiO4 Solid Solution Crystals.
- Author
-
Fukuda, Koichiro and Kurokawa, Daisuke
- Subjects
- *
MORPHOLOGY , *SILICON oxide , *LIME (Minerals) , *CRYSTALS , *SCANNING electron microscopes , *CRYSTALLIZATION , *INDUSTRIAL chemistry , *CERAMICS , *CRYSTAL lattices - Abstract
Single crystals of α′L-(Sr0.3Ca1.7)SiO4 with well-developed smooth faces were grown by heating at 1473 K in a SrCl2 flux. A euhedral prismatic crystal ∼200 μm ×∼300 μm ×∼1000 μm in size was selected and examined by the combined use of the precession method and scanning electron microscope. Because the crystal developed within the stable temperature region of the α′H-phase, the faces were successfully identified as {111}, {011}, and {021} on the basis of the former α′H-phase lattice. The faces {011} and {021} constitute a zone with the zone axis [100], which was parallel to the elongation direction of the crystal. A similar morphology was confirmed for the belite crystals in a belite–gehlenite clinker, which were crystallized out of a melt within the stable temperature region of the α′H-phase. [ABSTRACT FROM AUTHOR]
- Published
- 2010
- Full Text
- View/download PDF
43. Structural and Optical Properties of Triclinic CuWO4 Prepared by Solid‐State Reaction Technique.
- Author
-
Yadav, Pritam and Sinha, Ela
- Subjects
- *
OPTICAL properties , *ABSORPTION spectra , *RAMAN spectroscopy , *SCANNING electron microscopes , *CRYSTAL symmetry , *VIBRATIONAL spectra - Abstract
Copper tungstate CuWO4 ceramic is prepared by solid‐state reaction route at 850 °C for 3 h. The X‐ray diffraction (XRD) study proves that the synthesized composition possesses a monophasic triclinic structure with space group P1¯. The structural analysis (crystal symmetry and unit cell parameters) is investigated systematically using Rietveld refinement of the XRD patterns. Scanning electron microscope analysis of the sintered ceramics reveals the formation of dense microstructure with non‐uniform grains. The 16 active vibrational modes are observed in Raman spectra from 100 to 1000 cm−1. UV–vis absorption spectra revealed a direct allowed transition with band gap Eg = 2.23 eV. The photoluminescence (PL) emission spectra show intense yellow emission at room temperature. These results suggest the applications of CuWO4 as photocatalysts, photoanodes, and phosphors. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
44. Influence of Particle Size and Phase Connectivity on the Fracture Behavior of PA6/EOR Blends.
- Author
-
Heyn, Johannes and Bonten, Christian
- Subjects
- *
HYGROTHERMOELASTICITY , *POLYAMIDES , *PARTICLES , *GLASS transition temperature , *SCANNING electron microscopes , *MIXING - Abstract
Structure–property relations between the blend morphology and the fracture mechanical behavior of immiscible polyamide 6/ethylene‐octene copolymer (PA6/EOR) blends are investigated. The influence of a moisture uptake of the PA6 on the blend behavior is also demonstrated. Different blend formulations lead to different blend morphologies, which vary in particle sizes, interparticle spacing, and intensity of the phase connectivity between the blend partners. The intensity of the phase connectivity is described by the rheological behavior. The morphology, defined by the particle size and the calculated interparticle spacing, is analyzed optically by a scanning electron microscope. The shift of the glass transition temperature of the blends due to moisture uptake is demonstrated via dynamical mechanical analyses. All parameters are linked to the fracture mechanical properties determined by the method of the essential work of fracture. By means of the method of the essential work of fracture it is shown that the toughness increase by a given material combination and a constant soft phase amount depends only on the particle size. However, a basic requirement is always strong phase connectivity between the blend partners. Thus, by a given material combination the smaller the soft phase particles within the matrix, the higher the increase in toughness. A moisture uptake does influence the blend properties in many ways and also leads to a change in the fracture behavior. Therefore, it is not possible to predict the fracture mechanical behavior of hydrophilic blends from one condition state to another. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
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