Investigation on Microstructural Characteristics and Mechanical Properties of Thermally Sprayed Fe-Base Composites Reinforced with Different Ceramic Particulates

2021 ◽  
Author(s):  
Fardad Azarmi ◽  
X.W. Tangpong
Keyword(s):  
Amorphous Structure ◽  
The Other ◽  
Microstructural Characteristics ◽  
Microstructural Observation ◽  
Steel Coating ◽  
Two Samples ◽  
Morphology And Structure ◽  
Detonation Gun ◽  
Thermally Sprayed ◽  
Spraying Process

Abstract Three different coatings were deposited using the Detonation Gun Spraying (DGS) technology from steel powders alone; and steel powers mixed with Fe3C and SiC particles; respectively. The microstructural characteristics of these coatings were examined and the hardness of each type of coating was studied. The morphology and structure of the feedstock powders were affected by the exposure to high temperature during the spraying process and rapid solidification of steel powders that resulted in the formation of an amorphous structure. The unreinforced steel coating had the highest hardness among the three types of coatings; possibly due to a higher degree of amorphization in the coating compared to the other two samples. The microstructural observation confirmed the formation of dense coatings with a layered structure with good connectivity between layers with minimum defects and porosities in the interfacial regions.

scholarly journals Hardening Properties of Cheeses by Latilactobacillus curvatus PD1 Isolated from Hardened Cheese-Ddukbokki Rice Cake

2021 ◽  
Vol 9 (5) ◽  
pp. 1044
Author(s):  
Jeong A Kim ◽  
Geun Su Kim ◽  
Se Mi Choi ◽  
Myeong Seon Kim ◽  
Do Young Kwon ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Acid Production ◽  
Lactobacillus Casei ◽  
Leuconostoc Mesenteroides ◽  
The Other ◽  
Rice Cake ◽  
Two Samples ◽  
High Protease Activity

Hardening of cheese is one of major issues that degrade the quality of Home Meal Replacement (HMR) foods containing cheese such as Cheese-ddukbokki rice cake (CD, stir-fried rice cakes with shredded cheese). The quality of cheese, such as pH, proteolytic, and flavor properties, depends on various lactic acid bacteria (LAB) used in cheese fermentation. The hardening of cheese is also caused by LAB. In this study, various LAB strains were isolated from CD samples that showed rapid hardening. The correlation of LAB with the hardening of cheese was investigated. Seven of the CD samples with different manufacturing dates were collected and tested for hardening properties of cheese. Among them, strong-hardening of cheese was confirmed for two samples and weak-hardening was confirmed for one sample. All LAB in two strong-hardening samples and 40% of LAB in one weak-hardening sample were identified as Latilactobacillus curvatus. On the other hand, most LAB in normal cheese samples were identified as Leuconostoc mesenteroides and Lactobacillus casei. We prepared cheese samples in which L. curvatus (LC-CD) and L. mesenteroides (LM-CD) were most dominant, respectively. Each CD made of the prepared cheese was subjected to quality test for 50 days at 10 °C. Hardening of cheese with LC-CD dominant appeared at 30 days. However, hardening of cheese with LM-CD dominant did not appear until 50 days. The pH of the LC-CD was 5.18 ± 0.04 at 30 days, lower than that of LM-CD. The proteolytic activity of LC-CD sample was 2993.67 ± 246.17 units/g, higher than that of LM-CD sample (1421.67 ± 174.5 units/g). These results indicate that high acid production and high protease activity of L. curvatus might have caused hardening of cheese.

Pressure Drop Measurements for Air Flow Through Open-Cell Aluminum Foam

2004 ◽  
Author(s):  
Nihad Dukhan ◽  
Angel Alvarez
Keyword(s):  
Reynolds Number ◽  
Pressure Drop ◽  
Flow Rate ◽  
Aluminum Foam ◽  
Flow Direction ◽  
The Other ◽  
Turbulent Regime ◽  
Thick Sample ◽  
Open Cell ◽  
Two Samples

Wind-tunnel pressure drop measurements for airflow through two samples of forty-pore-per-inch commercially available open-cell aluminum foam were undertaken. Each sample’s cross-sectional area perpendicular to the flow direction measured 10.16 cm by 24.13 cm. The thickness in the flow direction was 10.16 cm for one sample and 5.08 cm for the other. The flow rate ranged from 0.016 to 0.101 m3/s for the thick sample and from 0.025 to 0.134 m3/s for the other. The data were all in the fully turbulent regime. The pressure drop for both samples increased with increasing flow rate and followed a quadratic behavior. The permeability and the inertia coefficient showed some scatter with average values of 4.6 × 10−8 m2 and 2.9 × 10−8 m2, and 0.086 and 0.066 for the thick and the thin samples, respectively. The friction factor decayed with the Reynolds number and was weakly dependent on the Reynolds number for Reynolds number greater than 35.

Fatigue behavior of a thermally sprayed low carbon steel coating

2000 ◽  
Vol 277 (1-2) ◽  
pp. 176-182 ◽  
Author(s):  
Pi Lin Liu ◽  
Jian Ku Shang ◽  
Oludele O Popoola
Keyword(s):  
Carbon Steel ◽  
Fatigue Behavior ◽  
Low Carbon Steel ◽  
Low Carbon ◽  
Steel Coating ◽  
Thermally Sprayed

Manipulating the Structure and Morphology of Cobalt-Boron Nanoparticles through a Chemical Approach

2013 ◽  
Vol 829 ◽  
pp. 762-766 ◽  
Author(s):  
Hooman Sabarou ◽  
Abolghasem Ataie
Keyword(s):  
Growth Process ◽  
Ph Value ◽  
Amorphous Structure ◽  
Detailed Characterization ◽  
Synthesis Mechanism ◽  
Subsequent Formation ◽  
Structure And Morphology ◽  
Morphology And Structure ◽  
Structure Phase

Cobalt-boron nanoparticles have been synthesized by a chemical reaction between NaBH4 and CoCl2.6H2O through manipulating pH value of the reaction mixture. The morphology, structure, phase composition, and thermal behavior have been examined via FESEM, TEM, XRD, EDS, and DSC techniques, respectively. It is demonstrated that the morphology and structure of ultimate nanoparticles completely depends on the pH value of reaction mixture. While the neutral pH value favors the smallest nanoparticles with a mean particle size of 50 nm and complete amorphous structure, the acidic condition promotes the growth process and the crystal structure. Furthermore, these nanoparticles transform into cobalt nanocrystallites after heated at 600°C, and retained the discrepancies in the morphology and the structure of the parent cobalt-boron nanoparticles. A detailed characterization of the nanoparticulates, discussions on the synthesis mechanism, and subsequent formation transformation have been provided.

Detrital and authigenic minerals in sediments from the western part of the Indian Ocean

1986 ◽  
Vol 50 (355) ◽  
pp. 69-74 ◽  
Author(s):  
A. E. Tsirambides
Keyword(s):  
Indian Ocean ◽  
Oxygen Isotope ◽  
Western Indian Ocean ◽  
The Other ◽  
Authigenic Minerals ◽  
Volcanic Material ◽  
Two Samples ◽  
The Indian Ocean ◽  
Isotope Analyses ◽  
Mn Oxides

AbstractMineralogical and oxygen isotope analyses have been performed on nine western Indian Ocean core samples in order to distinguish the detrital from authigenic minerals in the sediments. Following the removal of carbonates, organic constituents and Fe and Mn oxides, the residue was separated into five size fractions, the principal minerals present being feldspar, quartz, clinoptilolite, and clay minerals.Oxygen isotope compositions for two samples reflect an authigenic origin for clinoptilolite by the submarine alteration of volcanic material. Oxygen isotope compositions of two separates (free from feldspar and clays) suggest a detrital origin for the quartz in this area. The same mode of origin is apparent for the other components too, except possibly for some smectite which may have formed authigenically.

scholarly journals A Study of the Micropore Structure of Carbonized Rayon Yarn by Nitrogen Adsorption and Nonane Pre-Adsorption

1985 ◽  
Vol 2 (2) ◽  
pp. 89-95 ◽  
Author(s):  
J. N. Bohra ◽  
K. S. W. Sing
Keyword(s):  
External Surface ◽  
Nitrogen Adsorption ◽  
The Other ◽  
Adsorption Method ◽  
Micropore Structure ◽  
Surface Areas ◽  
Three Samples ◽  
Two Samples ◽  
Before And After ◽  
Gain Access

Adsorption isotherms of nitrogen have been determined at 77 K on three samples of carbonized rayon yarn, both before and after the pre-adsorption of n-nonane. In their original state the three samples were all highly microporous. Application of the αs-method of isotherm analysis reveals that their micropore volumes were 0·17–0·19 cm3g−1 and their external surface areas 20–27 m2g−1 (the corresponding BET areas being 427–483 m2g−1). Nonane pre-adsorption resulted in blockage of the entire micropore structure only in the case of one sample: micropore volumes ∼0·1 cm3g−1 were still available for nitrogen adsorption in the other two samples. It appears that nitrogen molecules were able to gain access to some parts of these micropore structures through wider pore entrances which were not completely blocked by the pre-adsorbed nonane. The work has shown that the nonane pre-adsorption method requires further investigation before it can be used with confidence for the assessment of microporosity.

scholarly journals The Cold Gas Content of Elliptical Galaxies

1996 ◽  
Vol 171 ◽  
pp. 393-393
Author(s):  
W.K. Huchtmeier ◽  
L.J. Sage ◽  
C. Henkel
Keyword(s):  
Molecular Hydrogen ◽  
Neutral Hydrogen ◽  
Elliptical Galaxies ◽  
Radial Velocities ◽  
The Other ◽  
Gas Content ◽  
Global Properties ◽  
Two Samples ◽  
Nearby Galaxies ◽  
Cold Gas

The 100m radiotelescope at Effelsberg has been used to observe two samples of elliptical galaxies in the 21cm line of neutral hydrogen. One sample is defined by the elliptical galaxies in the Revised-Shapely-Ames catalog (RSA) (Huchtmeier 1994, Astron.Astrophys 286, p.389); the other sample is defined by all elliptical galaxies with IRAS 100 μ fluxes ≥ 500mJy north of declination –310 (Huchtmeier, Sage, Henkel 1995 Astron.Astrophys. in press). Among the detected galaxies there are 23 (RSA) and 24 (IRAS) isolated elliptical galaxies free of confusion by nearby galaxies with similar radial velocities. Global properties of these two samples of elliptical galaxies are discussed: their HI-properties, optical and IR luminosities, their optical colors, their masses of dust and of molecular hydrogen.

scholarly journals Genetic variability in four samples of Neoplecostomus yapo (Teleostei: Loricariidae) from the rio Paranapanema basin, Brazil

2009 ◽  
Vol 7 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Juliana S. Philippsen ◽  
Erasmo Renesto ◽  
Ana Maria Gealh ◽  
Roberto F. Artoni ◽  
Oscar A. Shibatta ◽  
...  
Keyword(s):  
Genetic Variability ◽  
Genetic Distance ◽  
Corn Starch ◽  
The Other ◽  
Allozyme Electrophoresis ◽  
Polymorphic Loci ◽  
Two Samples ◽  
Starch Gel ◽  
The Mean ◽  
Electrophoresis Technique

Four samples of Neoplecostomus yapo were analyzed through the allozyme electrophoresis technique in corn starch gel. The allozyme pattern was similar to those found in N. paranensis with 24 loci scored. Two samples (ribeirão Atlântico and ribeirão Uraí) showed monomorphic bands for all 24 loci, whereas the other two (rio Verde and rio Fortaleza) showed 8.3% of polymorphic loci. The He genetic variability estimates for the rios Verde and Fortaleza populations were 0.0195 and 0.0179, respectively, too much inferior to the mean heterozygosity summed to species from the whole world (0.051). The Wright statistical values F IS = 0.5181, F IT = 0.5681 and F ST = 0.1039 and the genetic distance of Nei values showed that the four samples are genetically very similar to each other and that there is homozygote excess in the polymorphic loci.

Microbiological Sampling of Carcasses by Excision or Swabbing with Three Types of Sponge or Gauze

2010 ◽  
Vol 73 (1) ◽  
pp. 81-87 ◽  
Author(s):  
BERNARDO MARTÍNEZ ◽  
M. FELICIDAD CELDA ◽  
BEGOÑA ANASTASIO ◽  
INÉS GARCÍA ◽  
M. CARMEN LÓPEZ-MENDOZA
Keyword(s):  
Production Process ◽  
Animal Species ◽  
The Other ◽  
Aerobic Bacteria ◽  
Cellulose Sponge ◽  
Two Samples ◽  
Viable Bacteria ◽  
Polyurethane Sponge ◽  
The Mean

Fifty-five bovine, 50 equine, 60 ovine, and 50 porcine carcasses were sampled in a slaughterhouse in eastern Spain. Two samples were taken from each carcass, one using the excision method and the other using the swabbing method. Four different materials were used for swabbing: cellulose, polyurethane, or viscose sponges, and medical gauze. Samples were collected at the end of the process by four different people before the carcasses were taken to the cooler. The samples were examined for total viable bacteria counts (TVCs) and Enterobacteriaceae counts (ECs). The mean TVC for all species sampled by excision was 4.50 log CFU/cm2, which was significantly higher than the 3.53 log CFU/cm2 obtained by swabbing. The TVCs obtained using gauze and the cellulose and polyurethane sponges were significantly higher (P < 0.05) than the corresponding TVCs obtained using viscose sponges. Animal species, the person who collected the samples, and microbiological load also had a significant effect on TVC. ECs were obtained from 82.8% of excision samples, from larger percentages of samples obtained using cellulose or polyurethane sponges or gauze swabs, but from smaller percentages of samples obtained using viscose sponges. The Enterobacteriaceae load significantly influenced the EC. In contrast, animal species and the person who collected the samples had no significant effect. The cellulose sponge, polyurethane sponge, and gauze gave high mean log counts of aerobic bacteria and Enterobacteriaceae, which makes these swab types suitable for use in slaughterhouses for the purpose of assessing production process hygiene.

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