scholarly journals Modified phosphate coatings applied to steel by cold method

2021 ◽  
Vol 2131 (4) ◽  
pp. 042027
Author(s):  
V Rumyantseva ◽  
V Konovalova ◽  
B Narmaniya
Keyword(s):  
Low Temperatures ◽  
Smooth Surface ◽  
Phosphate Coating ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Zinc Phosphates ◽  
Speed Up ◽  
Fine Crystalline Structure ◽  
Iron Manganese ◽  
Positive Effect

Abstract The deposition of phosphate coatings occurs on the surface of the product when it is immersed in a solution containing phosphoric acid. The formation of a film on the metal surface occurs during the deposition of insoluble two- and three-substituted phosphates of iron, manganese, and zinc from a solution. To speed up the process and conduct phosphating at low temperatures, nitrates, nitrites, and fluorides of active metals are introduced into the solution. Organic compounds, such as glucose, glycerin, Trilon A, and Trilon B, are buffer additives to maintain the pH of phosphating solutions in the range of 2.6-3.2. It was found that 10-15 minutes at a process temperature of 20-25 °C are sufficient for the formation of a protective phosphate coating from solutions containing modifiers. The content of zinc phosphates in the modified phosphate coatings is increased. Additives in cold phosphating solutions have a positive effect on the quality and protective properties of the resulting phosphate films. Modified phosphate coatings obtained by the cold method have a fine-crystalline structure, a smooth surface and low porosity.

scholarly journals Effect of Modifiers Introduced into Cold Phosphating Solutions on the Physical and Mechanical Properties of the Formed Phosphate Films

2021 ◽  
Vol 346 ◽  
pp. 01034
Author(s):  
Viktoriya Konovalova
Keyword(s):  
Low Temperatures ◽  
Traditional Method ◽  
Physical And Mechanical Properties ◽  
Active Centers ◽  
Protective Properties ◽  
Small Thickness ◽  
High Adhesion ◽  
Phosphate Coatings ◽  
Low Wear ◽  
Electrical Insulation Properties

This work is devoted to the study of the physical-mechanical and protective properties of modified phosphate coatings obtained on steel by cold method. Modifiers introduced into phosphating solutions are buffer additives, stabilize the phosphating process, allow the deposition of coatings at low temperatures, increase the number of active centers on the metal surface, resulting in fine-crystalline uniform coatings of small thickness. It was found that the corrosion rate of modified phosphate films is 2 times less than that of coatings obtained by the traditional method. When the temperature rises above 100 °C, the corrosion resistance of phosphate coatings decreases, and the satisfactory protective properties of the modified films are preserved when heated to 200 °C. Modified phosphate coatings have a high adhesion strength to the metal due to their small thickness. However, thin phosphate coatings have low wear resistance and medium electrical insulation properties.

A Comparative Study of GaN Films Grown on Different Faces of Sapphire by ECR-Assisted MBE

1992 ◽  
Vol 242 ◽  
Author(s):  
T. D. Moustakas ◽  
R. J. Molnar ◽  
T. Lei ◽  
G. Menon ◽  
C. R. Eddy
Keyword(s):  
Surface Morphology ◽  
Low Temperatures ◽  
Smooth Surface ◽  
Growth Process ◽  
X Ray Diffraction ◽  
Epitaxial Relationship ◽  
X Ray ◽  
Sapphire Substrates ◽  
Growth Method ◽  
Step Growth

ABSTRACTGaN films were grown on c-plane (0001), a-plane (1120) and r-plane (1102) sapphire substrates by the ECR-assisted MBE method. The films were grown using a two-step growth process, in which a GaN buffer is grown first at relatively low temperatures and the rest of the film is grown at higher temperatures. RHEED studies indicate that this growth method promotes lateral growth and leads to films with smooth surface morphology. The epitaxial relationship to the substrate, the crystalline quality and the surface morphology were investigated by RHEED, X-ray diffraction and SEM studies.

scholarly journals Behavior and Energy Losses of Cows during the Period of Low Temperatures

2021 ◽  
Vol 24 (5) ◽  
pp. 46-53
Author(s):  
Oleksandr O. Borshch ◽  
Oleksandr V. Borshch ◽  
Yurii Mashkin ◽  
Vasyl Malina ◽  
Maxim Fedorchenko
Keyword(s):  
Low Temperatures ◽  
Heat Insulation ◽  
Energy Losses ◽  
Strong Wind ◽  
The Past ◽  
Air Temperatures ◽  
The Difference ◽  
And Behavior ◽  
Positive Effect ◽  
Moderate Climate

Over the past 20 years, dairy farms in Ukraine have been actively introducing the keeping of cows in easy-to-assemble premises. However, in a moderate climate (with four distinct year seasons), the issues of microclimate, energy losses of animals and their behavior during the cold period of the year for keeping in such premises have not been fully studied. The purpose of this work was to study the influence of the heat insulation elements use of side curtains in easy-to-assemble premises during the period of low temperatures on microclimate, energy outgoings for thermoregulation and behavior of cows. The research conducted in the central part of Ukraine (Kyiv region). The research was conducted during January-February (29-43 days of the year) 2021. This period characterized by low average daily temperatures of -12.2– -18.7°С, strong wind gusts and daily precipitation in the form of snow. Two easy-toassemble premises for 400 heads were used for research. Parameters of placements (LxWxH): 150х32х10.5 m. The first one was without the use of curtains heat insulation elements, and the second one was with these elements of heat insulation. It was found that the use of polycarbonate wall heat insulation elements had a positive effect on the microclimate in the placement during the period of low temperatures. Indicators of average daily air temperatures in the placement were 3.2 and 8.8°C higher compared to the temperature in the same premise without the use of heat insulation elements and the environment. The wind speed also differed by 0.18 and 11.04 m/s, respectively. In addition, the heat insulation of the walls affected the temperature under the lying cow (+1.8°C), energy outgoings for thermoregulation (-1.93 MJ) and the number of cows that lay in the period of the lowest temperatures (+3.23-9.83%) compared to the placement without heat insulation elements. The difference in temperature of rubber carpet in the compared premises was significant: +3.3°C in the premises with heat insulation elements compared to the premises without heat insulation

The protective properties of various phosphate coatings on steel

2007 ◽  
Vol 4 (11) ◽  
pp. 581-595 ◽  
Author(s):  
J. F. Andrew ◽  
S. G. Clarke ◽  
E. E. Longhurst
Keyword(s):  
Protective Properties ◽  
Phosphate Coatings

Radiometric Study of Phosphate Coatings Formed on Steel in Pretreatment Baths★

CORROSION ◽  
1954 ◽  
Vol 10 (9) ◽  
pp. 285-288 ◽  
Author(s):  
THOMAS F. BOYD ◽  
MICHAEL GALAN ◽  
LEONARD MARKOWITZ
Keyword(s):  
Phosphoric Acid ◽  
Sodium Nitrite ◽  
Sodium Phosphate ◽  
Diammonium Phosphate ◽  
Phosphate Coating ◽  
Sodium Dichromate ◽  
Corrosion Resistant ◽  
Phosphate Coatings ◽  
Corrosion Resistant Coatings ◽  
Sodium Phosphates

Abstract An investigation has been made of the amount of phosphate coating formed on steel by various rustinhibiting solutions. The treatments used were phosphoric acid, phosphoric acid with sodium dichromate and sodium nitrite with diammonium phosphate and with sodium phosphates. No correlation was found between the amount of phosphate coating formed and corrosion resistance. The nature of the coating appears to be the significant factor. The most corrosion resistant coatings were formed by diammonium phosphate-sodium nitrite and sodium phosphate-sodium nitrite treatments, the least by phosphoric acid alone.

scholarly journals Effect of spatial characteristics on campus open space uses of youth: Example of KTU Kanuni CampusGençlerin kampüs açık mekân kullanımlarına mekânsal özelliklerin etkisi: KTÜ Kanuni Kampüsü örneği

2017 ◽  
Vol 14 (3) ◽  
pp. 2417
Author(s):  
Tuğba Düzenli ◽  
Elif Merve Alpak ◽  
Ali Özbilen
Keyword(s):  
Young People ◽  
Open Space ◽  
Development Process ◽  
Personality Development ◽  
Environmental Design ◽  
Open Spaces ◽  
University Campuses ◽  
Friendship Relations ◽  
Speed Up ◽  
Positive Effect

It is necessary to assess the environment in terms of the development of young people; Young people need to spend time in appropriate places to speed up the development process and increase the influence of the youth process on personality development. When assessed from the perspective of environmental design, university campuses are one of the most important places where young people's friendship relations intensify and social roles begin to develop as well as to acquire skills related to their professions. In this study, open spaces of Karadeniz Technical University Kanuni Campus were first classified in terms of the characteristics (mobility, naturalness, openness) that should be possessed by the youth places determined in the literature and then the use of youth was observed in these places. 3 of them were high in terms of the determined characteristics and 3 were low. A total of 6 campus locations were observed and how young people used the spaces. As a result, it was found that spaces with higher levels of characteristics were more successful, more used by younger people, and group use was more intense. In other words, mobility, naturalness and openness were found to have a positive effect on campus.Extended English abstract is in the end of PDF (TURKISH) file. ÖzetGençlerin gelişimi açısından çevreyi değerlendirmek gereklidir; gençlerin gelişim sürecini hızlandırmak, gençlik sürecinin kişilik gelişimine etkisini arttırmak için uygun mekânlarda zaman geçirmeleri gerekir. Çevre tasarımı açısından değerlendirildiğinde, meslekleriyle ilgili donanımlarını kazanmaları yanında gençlerin arkadaşlık ilişkilerinin yoğunlaştığı ve sosyal roller geliştirmeye başladığı önemli mekânlardan biri de üniversite kampüsleridir. Bu çalışmada da Karadeniz Teknik Üniversitesi Kanuni Kampüsü açık mekânları önce literatürden belirlenen genç mekânlarının sahip olması gereken özellikler (hareketlilik, doğallık, açıklık) bakımından sınıflandırılmış, daha sonra bu mekânlarda gençlerin kullanımları gözlemlenmiştir. 3’ü belirlenen özellikler bakımından yüksek, 3 ü düşük olmak üzere toplam 6 kampüs mekânında davranış gözlemi yapılmış, gençlerin mekânları nasıl kullandığı incelenmiştir. Sonuçta özellikler açısından düzeyleri yüksek olan mekânların dahabaşarılı olduğu ve daha çok genç tarafından kullanıldığı ve grup kullanımının yoğunluktaolduğu ortaya çıkmıştır. Yani hareketlilik, doğallık, açıklık özelliklerinin kampüs mekân kullanımını olumlu yönde etkilediği belirlenmiştir.// Annotate Highlight

scholarly journals Effect of Additive of Polymetallic Ores’ Tailin gs on Properties of Composite Cements

2016 ◽  
Vol 18 (2) ◽  
pp. 153 ◽  
Author(s):  
A.Zh. Aymenov ◽  
N.B. Sarsenbayev ◽  
T.M. Khudyakova ◽  
B.K. Sarsenbayev ◽  
A.T. Batyrkhanov ◽  
...  
Keyword(s):  
High Strength ◽  
Chemical Processes ◽  
High Tech ◽  
X Rays ◽  
Protective Properties ◽  
X Ray ◽  
Physical Chemical ◽  
Technological Production ◽  
Composite Cements ◽  
Positive Effect

The article analyzes the use of polymetallic ores’ tailings as a basis for production of composite cements and concrete, having protective properties against gamma and X-rays radiation, as well as high strength and lifetime. The main practically significant result is: the development of scientific and technological production bases of new high-tech type of multicomponent hydraulic binders for concretes – composite cements; the identification of new hydration products in composite cements with addition of polymetallic ores’ tailings; the development of optimal compositions of composite cements for concretes. It is established that the composite cements, that developed by us on the basis of polymetallic ores’ tailings, meet modern requirements i.e. its improve the construction-technical properties of material, have positive effect to the environment situation and allow to reduce the production cost of the final product. Their technology is low metal-intensive and<br />power-consuming. Studies of physical-chemical processes of composite cements structure formation with addition of polymetallic ores’ tailings have been conducted using methods such as chemical, X-ray phase, differential-thermal and electronmicroscopic analysis methods.

scholarly journals Obtaining Luminous Phosphate Coatings on Steel by Cold Method

2022 ◽  
Author(s):  
V.S. Konovalova
Keyword(s):  
Uniform Distribution ◽  
Organic Additives ◽  
Green Phosphor ◽  
Protective Properties ◽  
Phosphate Coatings ◽  
Steel Surfaces ◽  
Phosphate Film

Abstract. The possibility of obtaining luminous phosphate coatings on steel by cold method has been studied. Modified cold phosphating solutions containing organic additives (glycerin, trilon B, OS-20 emulsifier) were selected as the basis to maintain the pH, stabilize the solution and improve the quality and structure of the deposited coatings. To obtain the glow effect, a green phosphor based on Zn2SiO4 containing manganese as a sensitizer was added to the phosphating solution. During deposition, phosphate coatings are obtained that glow with spots, but constant mixing of the solution during deposition contributes to the uniform distribution of phosphor in the phosphate film. Luminous phosphate coatings have good protective properties, they can be used as an independent protection of steel surfaces from corrosion.

scholarly journals Anaerobic methanotrophic communities thrive in deep submarine permafrost

2017 ◽  
Author(s):  
Matthias Winkel ◽  
Julia Mitzscherling ◽  
Pier P. Overduin ◽  
Fabian Horn ◽  
Maria Winterfeld ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Marker Genes ◽  
Anaerobic Oxidation Of Methane ◽  
Oxidation Of Methane ◽  
Iron Manganese ◽  
Archaeal Communities ◽  
Permafrost Sediments ◽  
Methane Concentrations ◽  
Methanotrophic Communities

AbstractThawing submarine permafrost is a source of methane to the subsurface biosphere. Methane oxidation in submarine permafrost sediments has been proposed, but the responsible microorganisms remain uncharacterized. We analyzed archaeal communities and identified distinct anaerobic methanotrophic (ANME-2a/b, ANME-2d) assemblages in frozen and completely thawed submarine permafrost sediments. Besides archaea potentially involved in AOM we found a large diversity of archaea mainly belonging to Bathyarchaeota, Thaumarchaeota, and Euryarchaeota. Methane concentrations and δ13C-methane signatures distinguish horizons of potential anaerobic oxidation of methane (AOM) coupled either to sulfate reduction in a sulfate-methane transition zone (SMTZ) or to the reduction of other electron acceptors, such as iron, manganese or nitrate. Analysis of functional marker genes (mcrA) and fluorescence in situ hybridization (FISH) corroborate AOM communities in submarine permafrost sediments potentially active at low temperatures. Extrapolating potential AOM rates, when scaled to the total area of expected submarine permafrost thaw, reveals that methane could be consumed at rates between 8 and 120 Tg C per year, which is comparable to other AOM habitats such as seeps, continental SMTZ and wetlands. We thus propose that AOM is active where submarine permafrost thaws and needs to be accounted for in global methane budgets.

Study of magnetic and transport properties of Bi2Se3/FeSe2 bilayer thin films

2021 ◽  
Vol 35 (02) ◽  
pp. 2150022
Author(s):  
J. Zhang ◽  
K. Zhao ◽  
X. S. Yang ◽  
Y. Zhao
Keyword(s):  
Thin Films ◽  
Proximity Effect ◽  
Low Temperatures ◽  
Smooth Surface ◽  
Room Temperature ◽  
Magnetic Order ◽  
Spin Orbit Coupling ◽  
Bilayer Films ◽  
Linear Magnetoresistance ◽  
Strong Spin

Thin films of topological insulator (TI) Bi2Se3 were grown onto the surfaces of FeSe2 layers of different thicknesses on Si (100) substrates by magnetron sputtering, forming bilayer films with smooth surface. Magnetic and transport measurements indicate ferromagnetism in these bilayer samples. Large coercive fields at low-temperatures and a room-temperature magnetic order were observed. Moreover, nonsaturated high-filed linear magnetoresistance (MR) and weak anti-localization effect were found in these bilayer thin films. These results indicate that the bilayer samples could have both strong spin–orbit coupling and ferromagnetic proximity effect, which are the desired features.

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