Anticorrosive Property of Potassium Dichromate Film on Galvanized Coating in Distilled Water

2015 ◽  
Vol 227 ◽  
pp. 135-138
Author(s):  
Olayide Rasaq Adetunji ◽  
Peter Olaitan Aiyedun ◽  
Oladimeji Suleiman Bello
Keyword(s):  
Potassium Dichromate ◽  
Optical Microscope ◽  
Distilled Water ◽  
White Rust ◽  
Steel Sheets ◽  
Weight Losses ◽  
Water Ph ◽  
Analysis Of Results ◽  
Galvanized Coating ◽  
Microsoft Office

Hot Dip Galvanized (HDG) coating protects steel from corrosion by providing a thick, tough metallic zinc envelope, which completely covers the steel surface and seals it from the corrosive action of its environment. The anti-corrosion ability of this sacrificial anode cathodic protection can be improved upon through the protective nature of passivation films on zinc like potassium dichromate.This study investigated the anti-corrosion effect of potassium dichromate (K2Cr2O7) film on freshly galvanized coating in distilled water (pH=7.92). The K2Cr2O7film passivity on the hot-dip zinc coated steel sheets (taken as treated in the context of this study) was used in direct comparison with their untreated counterparts. The test was run for 30 days at 120 hours interval during which the corresponding weight losses, corrosion rates, inhibitor efficiencies, and pH of the final solutions were obtained of the coupons. Analysis of results was made using Microsoft office applications. The surface morphology of the samples was obtained using Optical microscope. The results obtained revealed the greater influence of the action of the K2Cr2O7film on selected and examined HDG steel sheets corrosion performance. Weight losses increased with increase in immersion time. Inhibitor efficiency of 4.1% was achieved. The photomicrographs confirmed the occurrence of corrosion on untreated coating more than the treated ones. Conclusively, potassium dichromate was effective in passivating galvanized coating from white rust.

A Study of the Effect of Starch Content on the Water Absorption of PVA/starch Blends

2021 ◽  
Vol 39 (1B) ◽  
pp. 150-158
Author(s):  
Bushra H. Musa ◽  
Nahida J. Hameed
Keyword(s):  
Water Absorption ◽  
Corn Starch ◽  
Starch Content ◽  
Optical Microscope ◽  
Distilled Water ◽  
Swelling Ratio ◽  
Blend Films ◽  
Weight Losses ◽  
Starch Blends ◽  
Spherical Voids

The present work aims to study physical tests such as the water absorption   tests of PVA; PVA/corn starch blends at different mass percent (25, 30, 35, 40, and 50%) of corn starch after immersion in distilled water for ten minutes. The blends were also characterized by FTIR analysis, and an optical microscope. Casting method used to prepare samples. The results of water absorption exhibited that the weight losses of the sample increases the starch content rises in the PVA matrix. Also, it was found the highest value of the swelling ratio % at (50% PVA /50% Starch) blend, while minimum values of the swelling ratio % at (75%PVA /25%Starch) blend and pure PVA film.    It was observed from optical microscope that the starch granules disperse well at 25 and 30 wt.% of the starch in the blend films. Nevertheless, clustering could be observed in the polymer blend at 35, 40, and 50 wt.% of starch component. It was shown that porous and spherical voids after the samples were immersed in distilled water.  

scholarly journals The Influence of Salt Solution on Morphological Changes in a Geosynthetic Clay Liner

2016 ◽  
Vol 2016 ◽  
pp. 1-8 ◽  
Author(s):  
Mochamad Arief Budihardjo
Keyword(s):  
Salt Solution ◽  
Morphological Changes ◽  
Microscopic Analysis ◽  
Optical Microscope ◽  
Distilled Water ◽  
Nacl Solution ◽  
Geosynthetic Clay Liner ◽  
Clay Liner ◽  
Morphological Variations ◽  
Crystal Deposit

Morphological variations of geosynthetic clay liner (GCL) samples, hydrated with two different permeates, distilled water and NaCl solution (100 mM concentration), were observed in detail using microscopic analysis. After the GCL samples were hydrated with the NaCl solution, they were observed with an optical microscope. While the surface of the treated GCL samples was similar to the surface of the untreated GCL, a crystal deposit was found on the surface of the treated samples. Using a scanning electron microscope (SEM), a more solid appearance was observed for the bentonite particles contained in the GCL after the sample was hydrated with distilled water in comparison to the GCL sample that was hydrated with the NaCl solution. It appears that salt solution hydration results in less swelling of the bentonite particles. Furthermore, the energy-dispersive X-ray spectrometer (EDS) results showed that distilled water hydration had no effect on the distribution of the elements contained in the GCL samples. However, bound chlorine was observed, which demonstrated that the bentonite particles had absorbed the NaCl solution. In addition, changes in the hydraulic conductivity of the hydrated GCL samples were also observed.

Diversity and prevalence of gut parasites in urban macaques

2020 ◽  
Vol 1 (1) ◽  
pp. 34-41
Author(s):  
Bikram Sapkota ◽  
Roshan Babu Adhikari ◽  
Ganga Ram Regmi ◽  
Bishnu Prasad Bhattarai ◽  
Tirth Raj Ghimire
Keyword(s):  
Potassium Dichromate ◽  
Rhesus Macaques ◽  
Public Awareness ◽  
Parasitic Infection ◽  
Optical Microscope ◽  
Reservoir Host ◽  
Potassium Dichromate Solution ◽  
Gut Health ◽  
Fecal Samples ◽  
The Status

Rhesus macaques (Macaca mulatta) are commonly found to inhabit various religious sites and cities in Nepal. Similar to other nonhuman primates, they are also the natural or reservoir host of several gut parasites. However, the status of gut parasitism, particularly in the urban dweller macaques, remains largely unexplored in the country. This study aimed to assess the prevalence and diversity of gut parasites in the monkeys inhabiting Bajrabarahee, an urban temple area in Lalitpur District, Nepal. A total of 42 fresh fecal samples of macaques belonging to five different troops, were collected and preserved in 2.5% (w/v) potassium dichromate solution. The fecal samples were processed by direct wet mount, concentration, and acid-fast techniques and examined under an optical microscope. All the fecal samples were positive with gut parasites. The parasites detected were Ascarid spp., Balantidium coli, Cryptosporidium sp., Eimeria sp., Entamoeba coli, Entamoeba spp., Giardia sp., hookworm, Strongyloides sp., Strongylid spp., Trichomonas sp., and Trichuris sp. Cent percent prevalence rate and high species richness with 12 parasites may indicate that they have impact on the gut health of these monkeys. This suggests the need of deworming the macaque population and enhancing public awareness for pro-active control of parasitic infection as well as of adopting the preventive measures to lessen the zoonotic transmission of the pathogenic parasites.

scholarly journals Application of Bonded Joints for Quantitative Analysis of Adhesion

2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Jarmila Trpčevská ◽  
Mária Kollárová ◽  
Eva Zdravecká ◽  
Jana Tkáčová
Keyword(s):  
Steel Substrate ◽  
Zinc Coating ◽  
Experimental Tests ◽  
Coated Steel ◽  
Bonded Joints ◽  
Steel Sheets ◽  
Galvanized Coating ◽  
Zinc Coatings ◽  
Peel Tests

The performance of hot-dip coated steel sheets is associated with properties of the zinc coatings on steel substrate. For the characterization of the adhesion behaviour of zinc coating on steel various tests were employed. The study was focused on quantification assessment of galvanized coating adhesion to substrates. Methods for evaluation of the bonding strength of zinc coating by the shear strength and the T-peel tests applying four special types of adhesives were used. The experimental tests of bonded joints show that the adhesion of the zinc coating to the substrate was higher than that of the applied adhesive with the highest strength.

scholarly journals Leaching of Pb2+ and Te4+ in Yb3+ doped lead tellurite glasses in aqueous solution

2014 ◽  
Vol 8 (4) ◽  
Author(s):  
Khaidzir Hamzah ◽  
M. Abdullah Izat Mohd Yassin ◽  
Md. Rahim Sahar ◽  
Sib Krishna Ghoshal
Keyword(s):  
Aqueous Solution ◽  
Quantitative Analysis ◽  
Mass Spectrometer ◽  
Alkaline Solution ◽  
Acidic Solution ◽  
Distilled Water ◽  
Tellurite Glasses ◽  
Melt Quenching ◽  
Icp Ms ◽  
Water Ph

A series of Yb doped lead oxychloride tellurite glasses with composition of (80-x)TeO2-10PbO-10PbCl2-xYb2O3 were prepared using conventional melt quenching technique. These glasses were then immersed in distilled water (pH 4 and pH 9) for 10 days. The quantitative analysis of Pb2+ and Te4+ were made using induced coupled plasma-mass spectrometer (ICP-MS). The results showed that Te4+ and Pb2+ were highly leached in acidic solution or at lower pH compared to alkaline solution and the addition of Yb3+ in the glass system had reduced or maintained the leaching of Te4+ and Pb2+ from the glasses.

scholarly journals Research on milk homogenization in the stream homogenizer with separate cream feeding

10.5219/1289 ◽  
2020 ◽  
Vol 14 ◽  
pp. 142-148
Author(s):  
Kyrylo Samoichuk ◽  
Dmytro Zhuravel ◽  
Olga Viunyk ◽  
Dmytro Milko ◽  
Andrii Bondar ◽  
...  
Keyword(s):  
Milk Fat ◽  
Experimental Studies ◽  
Skim Milk ◽  
Digital Camera ◽  
Optical Microscope ◽  
Fat Globules ◽  
Fat Globule ◽  
Average Size ◽  
Microsoft Office

Homogenization, which is used in the technological schemes of production of most dairy products, is the most energy-intensive of the processes of mechanical processing of milk. One promising way to increase the energy efficiency of homogenization is to use separate homogenization and to use a little-researched stream homogenizer with separate cream feeding. The principle of its action is to pre-divide milk into cream and skim milk, and feed the fat phase with a thin stream into the stream of skim milk. This creates the conditions for achieving the high value of the Weber criterion – the main factor in the dispersion of milk fat. The purpose of these researches is to conduct experimental studies and determine the energy consumption and quality of homogenization of milk after treatment in a stream homogenizer. To achieve this goal, a designed experimental setup was used. The dispersive indices of the milk emulsion were determined by computer analysis of micrographs of milk samples obtained with an optical microscope and a digital camera using Microsoft Office Excel and Microsoft Visual Studio C # software using the OpenCV Sharp library. As a result of experimental studies, the critical value of the Weber criterion for homogenization of milk was determined, which is 28. The regularities of dispersion of milk fat in a stream homogenizer with separate feeding of the fat phase have been established. It is determined that the milk treatment in the experimental homogenizer allows us to achieve an emulsion with an average size of fat globules of about 0.8 μm (at the level of valve homogenizers). The value of the homogenization coefficient is obtained for the disruption of the fat globule in the conditions: subject to a single effect on the emulsion, without the influence of vibration and cavitation. This homogenization coefficient equals 3300 m3/2.s-1.

scholarly journals Influence of electrical conductivity on water uptake and vase life of cut gladiolus stems

2015 ◽  
Vol 21 (2) ◽  
pp. 221
Author(s):  
Lucas Cavalcante Da Costa ◽  
Fernanda Ferreira De Araújo ◽  
Teresa Drummond Correia Mendes ◽  
Fernando Luiz Finger
Keyword(s):  
Electrical Conductivity ◽  
Water Uptake ◽  
Room Temperature ◽  
Tap Water ◽  
Vase Life ◽  
Distilled Water ◽  
Cut Flowers ◽  
Water Ph ◽  
Maximum Water ◽  
Standard Composition

<p>Several experiments reveal that distilled water varies among different laboratories and also does not have a standard composition. Water electrical conductivity (EC) of vase solution is one of the parameters that influence the water uptake by cut flowers. Therefore, the objective of this work was to evaluate the influence of electrical conductivity on water uptake and vase life in cut stems of gladiolus. The stems harvested and kept in distilled water (pH 6.6, EC &lt;0.01dS m-1) and tap water (pH 7.0, EC 0.75 dS m-1) at room temperature. Flowers kept in tap water showed lower fresh weight loss after the second day and higher water uptake during vase life. In a second set of experiments, we verified the limit EC saturation supported by the flower. For this, flowers were placed in individual test tubes containing four different solutions with varying ion concentrations. Solution 2 (EC 0.60 dS m-1) promoted increased vase life and allowed maximum water uptake by the flowers. The results show that the electrical conductivity of vase solution is a major parameter in experiments with vase life of cut gladiolus. The presence of ions in the vase solution increases the overall vase life and improves water uptake of flowers with favorable optimal EC between 0.60 to 0.87 dS m-1.</p>

Culture studies on the mycobiont of Caloplaca erythrantha (Tuck.) Zahlbr. (Teloschistaceae): high production of major lichen secondary metabolites

2012 ◽  
Vol 44 (4) ◽  
pp. 533-542 ◽  
Author(s):  
Alejandra T. FAZIO ◽  
Mónica T. ADLER ◽  
María D. BERTONI ◽  
Marta S. MAIER
Keyword(s):  
Secondary Metabolites ◽  
Yeast Extract ◽  
Carbon Sources ◽  
Basal Medium ◽  
Secondary Compounds ◽  
Optical Microscope ◽  
Malt Extract ◽  
Distilled Water ◽  
Solid Media ◽  
High Concentrations

AbstractA strain of the lichen mycobiont of Caloplaca erythrantha, isolated from ascospores, was cultured axenically on different solid media. Four of the media employed supported the development of colonies and production of the two major lichen secondary metabolites. These media were: BMYE (mannitol 2%, yeast extract 0·1%, in Bold's basal medium); MEYE (malt extract 2%, yeast extract 0·2%, in distilled water); Hamada's MY10 (malt extract 1%, yeast extract 0·4%, sucrose 10%, in distilled water); and the new BMRM (Bold mannitol rich medium, mannitol 5·3%, malt extract 1%, yeast extract 0·4% in Bold's mineral medium). Percentages refer to final medium volume. The fungal colonies developed well on the four media and produced emodin and 7-chloroemodin, the major secondary compounds of the lichen apothecia. Crystals deposited richly on the external surface of the hyphae, as observed with an optical microscope. The two anthraquinones were purified from the lichen thallus, apothecia and cultured mycelia, and identified by chromatographic (TLC, HPLC) and spectroscopic (NMR, MS) methods. The analysis of lichen apothecia revealed the presence of emodin (0·90% w/w) and 7-chloroemodin (0·56% w/w), whereas colonies cultured for five months generally produced higher percentages than the lichen: 1·72% emodin and 0·30% 7-chloroemodin on BMYE; 0·21% and 0·95% on MEYE; 7·82% and 7·48% on MY10; and 11·70% and 10·80% on BMRM. These results show that the production of both anthraquinones was promoted significantly in mycobiont cultures with high concentrations of the carbon sources sucrose or mannitol, with a higher effect being observed with the latter.

Tribological Properties of Nano-Al2O3/PEEK Composites

2007 ◽  
Vol 330-332 ◽  
pp. 1239-1242 ◽  
Author(s):  
Dang Sheng Xiong ◽  
Jian Ming Lin ◽  
Ling Ling Liu
Keyword(s):  
Wear Resistance ◽  
Tribological Properties ◽  
Physiological Saline ◽  
Optical Microscope ◽  
Distilled Water ◽  
Fatigue Wear ◽  
Poly Ether Ether Ketone ◽  
Mass Fractions ◽  
Cause Of Failure ◽  
Worn Surfaces

Wear is the primary cause of failure of joint replacement prostheses. Poly(ether-ether-ketone)(PEEK) was reinforced with nano-Al2O3 particals of various mass fractions in this study. The effect of nanometer Al2O3 mass fractions on the contacted angle of the reinforced PEEK composites was investigated. Tribological properties of composites under distilled water and physiological saline lubrication condition was measured. And the morphologies of the worn surfaces were observed with optical microscope. The results shows that the wettability and wear resistance were all improved with appropriate nano-Al2O3.The wear resistance of composites filled with 7% nano-Al2O3 was the best under both distilled water and physiological saline lubrication. In addition, it can be found that there is serious plough on the surface of pure PEEK. This indicated that serious fatigue wear occurred on the worn surface of pure PEEK. Moreover, there are only light fatigue wear on the worn surfaces of PEEK composites filled with nano-Al2O3.

scholarly journals The Action of the -Glucosidase of Staohybotrys Atra on P-Nitrophenyl P-Quinovoside

1963 ◽  
Vol 16 (4) ◽  
pp. 926 ◽  
Author(s):  
MA Jermyn
Keyword(s):  
Aqueous Solution ◽  
Distilled Water ◽  
Michaelis Constant ◽  
Water Ph ◽  
Order Of Magnitude

p-Nitrophenyl /l-D-quinovopyranoside has been prepared and found to be a substrate for S. atra /l-glucosidase. The affinity of the enzyme for this substrate was an order of magnitude less than for p-nitrophenyl /l-glucoside, but of the same order as for many ortho-substituted aryl /l-glucosides. The Michaelis constant was 3�4 X 1O-4M (3�2 X 1O-5M for p-nitrophenyl /l-glucoside); the ratio V:h.x.!V~ax. was 0 �20 for the two p-nitrophenyl glycosides. It was rather difficult to make accurate measurements with the quinovoside since it was fairly unstable in aqueous solution. The rate of spontaneous decomposition of its solutions in distilled water (pH about 5�5) was some 20 times that of solutions of the glucoside.

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