Laser-Spark Modification of the Surfaces of Structural Materials by the Example of St3

2018 ◽  
Vol 284 ◽  
pp. 1268-1272
Author(s):  
S.G. Kuptsov ◽  
V.V. Shimov ◽  
R.S. Magomedova
Keyword(s):  
Wear Resistance ◽  
Construction Materials ◽  
Chemical Properties ◽  
Fold Increase ◽  
Hard Alloys ◽  
Laser Surface Modification ◽  
Abrasive Friction ◽  
Laser Spark ◽  
Physical And Chemical

The paper considers a technology for hardening construction materials using the hybrid (laser-spark) method by the example of steel St3 using hard alloys (VK8, stellite PR-V3K). A significant (several-fold) increase in the wear resistance of the coatings obtained is shown at resistance to abrasive friction due to the good quality of the coating layer and its microhardness (up to 60 GPa). Optimum modes for electrical spark and laser surface modification are proposed. Some physical and chemical properties of the coatings obtained (thickness, roughness, wear resistance, microhardness), as well as their dependence on the hybrid machining modes, are studied. The prospectivity of applying the hybrid (laser-spark) method for hardening of machine parts in order to increase their resistance to abrasive wear during friction is justified.

scholarly journals Effect of Slice Weight and Soaking Time on the Physico-Chemical Properties of Cassava Flour (Manihotesculentus) used for Bakery Products

2021 ◽  
pp. 10-24
Author(s):  
C. R. Abah ◽  
C. N. Ishiwu ◽  
J. E. Obiegbuna ◽  
E. F. Okpalanma ◽  
C. S. Anarado
Keyword(s):  
Chemical Properties ◽  
Process Variables ◽  
Soaking Time ◽  
Cassava Flour ◽  
Baked Goods ◽  
Cassava Root ◽  
Physico Chemical ◽  
Physical And Chemical ◽  
And Chemical Properties

Quality cassava(Manihotesculentus, Crantz) flour is often influenced by process variables such as slice weight and soaking time which may affect its nutritional quality. In this study, the effect of process variables (slice weight and soaking time) on quality of cassava flour was carried out. Cassava root was peeled, washed and cut into varied sizes (25.86 - 54.14 g) and soaked at varied time (7.03 - 40.97 h). The proximate composition, physical and chemical properties of the flour were carried out using standard methods. The result in our findings showed that slice weight and soaking time had significant increase (p<0.05) on the proximate and physico-chemical properties of the flour.The amylose and amylopectin content of the flour increased with increasing soaking time while the hydrogen cyanide content decreased with increase in soaking time. Overall, the quality cassava flour displayed desirable properties for its incorporation into baked goods.

scholarly journals The Effect of Coating as Antifungi of Harumanis Mango's Post Harvest Losses

2020 ◽  
Vol 1 (2) ◽  
pp. 7-16
Author(s):  
Winda Amilia ◽  
Andrew Setiawan Rusdianto ◽  
Arma Dwi Novemi
Keyword(s):  
Corn Starch ◽  
Chemical Properties ◽  
Inhibition Zone ◽  
Post Harvest ◽  
Physical Chemical ◽  
Chemical Content ◽  
Total Dissolved Solid ◽  
Tobacco Extract ◽  
Physical And Chemical

The amount of mango production in Indonesia is quite high, but the quality of postharvest mangoes is still quite low. The quality of the fruit will decline due to contamination; one of the contaminants is fungi. The way to reduce the damage of postharvest products is by coating applications. The purpose of this study was to study the physical, chemical and antifungal activities of harumanis mangoes’s quality which had been given coating during storage that could cause postharvest losses of harumanis mangoes. There are 3 treatments, each of them are respectively the provision of corn based coating  6% tobacco extract, 8% tobacco extract and 10% tobacco extract. The physical and chemical properties of the antifungal coating of tobacco extract made from corn coating for post-harvest damage on harumanis mangoes were obtained by weight loss, texture, colour, respiration rate, vitamin C and total dissolved solid. Preventing coating can prevent damage after harvest and protect the harumanis mango; therefore the quality of the mangoes can be maintained. The best results from the priority with the largest diameter inhibition zone were given corn starch 10% tobacco extract. Then the higher the concentration of extract used, the greater the diameter of the inhibition zone obtained. Based on all the tests performed (physical, chemical, and antifungal) the best treatment from the treatment was obtained that consisted of mangoes with antifungal layers of corn starch 10% tobacco extract. Because the P3 obtained the best results in maintaining physical, chemical content and fungi for 15 days.

scholarly journals Some physical and chemical properties of substrates designed for container production of spruce (Picea abies (L) Karst)

2004 ◽  
pp. 79-90
Author(s):  
Vesna Vratusa
Keyword(s):  
Woody Plants ◽  
Low Cost ◽  
Chemical Properties ◽  
Foreign Markets ◽  
Urban Green Spaces ◽  
Nursery Production ◽  
Countries In Transition ◽  
Physical And Chemical ◽  
And Chemical Properties

Efficient nursery production of woody plants, as well as the level of their successful application in urban green spaces, greatly depends upon properties of substrates in which these individuals grow, develop and endure. Furthermore, quality of substrate does not only affect the quality of future product (plant individual or green space), but distinctly determines its price. This element, extremely significant for all countries in transition, thus Serbia as well, commands finding ways of making qualitative, but least expensive substrate. The most logical solution is to use mixtures/substrates of precisely defined properties, composed of domestic components. Results presented in this paper imply that it is possible to create precisely such standard mixtures from domestic resources at relatively low cost, adjusted to needs of particular species, which would ultimately lead to successful, non-expensive nursery production and application of produced stock, both on domestic and foreign markets.

scholarly journals EFFECT OF THE LOG STORAGE OF Pinus taeda L. ON THE QUALITY OF KRAFT PULP

FLORESTA ◽  
2020 ◽  
Vol 50 (4) ◽  
pp. 1844
Author(s):  
Guilherme Giesel ◽  
Martha Andreia Brand ◽  
Flaviana Reis Milagres ◽  
Renato Augusto Pereira Damasio
Keyword(s):  
Pinus Taeda ◽  
Storage Time ◽  
Chemical Properties ◽  
Storage Period ◽  
Wood Properties ◽  
Pinus Taeda L ◽  
Solids Content ◽  
Physical And Chemical ◽  
Soluble Lignin

In pulp production, wood in logs is stored for periods that can range from a few weeks to several months. During storage, changes in the wood properties that affect the pulping process and the quality of the pulp may occur. The objective of this study was to determine the ideal timing of wood storage in logs by evaluating the variations (a) in the chemical properties of wood (b) in the parameters of the pulping process and (c) the quality of the Pinus taeda pulp. Logs were stored in an industrial courtyard for 30, 60, 90, 120 and 150 days. In each storage period, the physical and chemical properties of the wood, the cooking parameters, and the properties of the pulp were analyzed. The chemical properties of wood varied throughout storage, but only the solubility in sodium hydroxide showed a positive and significant correlation with storage time. In pulping, the yield and tailings had an inversely proportional correlation with the storage time, while the organic and total solids content had a positive correlation. As for cellulose quality, arabinan and soluble lignin contents did not vary during storage. The mannan content had a positive and significant correlation with the storage time. Taking into account all the variables analyzed, the storage time of P. taeda logs should be up to 30 days.

scholarly journals Effect of Bentonite on the Pelleting Properties of Iron Concentrate

2017 ◽  
Vol 2017 ◽  
pp. 1-6 ◽  
Author(s):  
Hao Liu ◽  
Bing Xie ◽  
Yue-lin Qin
Keyword(s):  
Water Absorption ◽  
Chemical Properties ◽  
Poor Quality ◽  
Physical And Chemical Properties ◽  
Iron Concentrate ◽  
Green Ball ◽  
Shock Temperature ◽  
Physical And Chemical ◽  
And Chemical Properties

The physical and chemical properties such as particle size, montmorillonite content, swelling degree, water absorption, and blue absorption of A, B, and C bentonites were studied under laboratory conditions. The effects of adding different quality and different proportion of bentonite on falling strength, compression strength, and shock temperature of green pellet were investigated. The experimental results show that the montmorillonite content, water absorption, and methylene blue absorption of bentonite-B are the highest. And the quality of bentonite-B is the best, followed by bentonite-C and bentonite-A poor quality. When the amount of bentonite-B reduced from 1.5% to 1.0%, the strength of green pellets and the shock temperature both decrease. As the same proportion of A, B, and C bentonites, the green-ball strength and shock temperature are as follows: bentonite-A > bentonite-B > bentonite-C.

Review: Low intensity ultrasonics in food technology / Revisión: Ultrasonidos de baja intensidad en tecnología de alimentos

1999 ◽  
Vol 5 (4) ◽  
pp. 285-297 ◽  
Author(s):  
A. Mulet ◽  
J. Benedito ◽  
J. Bon ◽  
N. Sanjuan
Keyword(s):  
Chemical Properties ◽  
Food Technology ◽  
Basic Principles ◽  
Low Intensity ◽  
Ultrasonic Techniques ◽  
Quality Of Food ◽  
Ultrasonic Parameters ◽  
Physical And Chemical ◽  
Non Destructive

Ultrasonic applications can be classified into low intensity or high intensity applications. The latter are used to modify a process or product with ultrasonics, while in low intensity applications the process or product modifies the ultrasonic signal, thus providing information about the product. Low inten sity ultrasonics in food technology can be used to monitor a process (liquid level, flowmeters) or to determine the quality of food products. Since ultrasonic techniques are rapid, non-destructive, easy to automate and relatively inexpensive, the number of applications is rapidly growing in this field. Ultrasonics can also be considered for use in laboratory testing devices to determine physical and chemical properties of foods. Ultrasonics has been used to determine texture, composition and physical state in liquid and solid foods. The commonly measured ultrasonic parameters are velocity, attenua tion and frequency spectrum composition. Velocity is the parameter used most since it is the simplest and most reliable measurement. This paper reviews the basic principles of ultrasonics, the most suit able techniques for each type of application, the testing devices needed to make measurements and the most interesting applications.

Effect of Elemental Sulfur on Corrosion in Sour Gas Systems

CORROSION ◽  
1991 ◽  
Vol 47 (4) ◽  
pp. 285-308 ◽  
Author(s):  
G. Schmitt
Keyword(s):  
Elemental Sulfur ◽  
Construction Materials ◽  
Chemical Properties ◽  
Medium Composition ◽  
Carbon Steels ◽  
Austenitic Steels ◽  
Partial Pressures ◽  
Corrosion Mechanisms ◽  
Liquid States ◽  
Physical And Chemical

Abstract The corrosive interaction of wet elemental sulfur with construction materials is reviewed, emphasizing effects of alloy composition (carbon steels, ferritic steels, austenitic steels, ferritic-austenitic [duplex] steels, Ni- and Co-base alloys, and titanium and its alloys), medium composition (salts, partial pressures of H2S and CO2, and acetic acid), and environmental conditions (temperature 20 to 250°C, stress). A summary of relevant physical and chemical properties of elemental sulfur is given to provide the fundamental basis for the understanding of sulfur corrosion. The different corrosion mechanisms found in the literature are critically discussed. Considering all data available, a mechanism is proposed explaining the electrochemical role of sulfur in the (physically) dissolved, solid, and liquid states. Methods for corrosion protection are outlined for carbon steels and corrosion-resistant alloys (CRA).

scholarly journals EFEITOS DE DIFERENTES SUBSTRATOS NA PRODUÇÃO DE MUDAS DE Sebastiania commersoniana

FLORESTA ◽  
2013 ◽  
Vol 43 (3) ◽  
pp. 407 ◽  
Author(s):  
Horácia Celina Armando Mula Boene ◽  
Antonio Carlos Nogueira ◽  
Nilton José Sousa ◽  
Dagma Kratz ◽  
Paulo Vitor Dutra de Souza
Keyword(s):  
Chemical Properties ◽  
Pine Bark ◽  
Forest Nursery ◽  
Coconut Fiber ◽  
Technical Feasibility ◽  
Rice Hulls ◽  
Controlled Irrigation ◽  
Physical And Chemical ◽  
And Chemical Properties

O objetivo do presente trabalho foi avaliar a viabilidade técnica da utilização de diferentes substratos para a produção de mudas de Sebastiania commersoniana e relacionar suas características físicas e químicas com a qualidade das mudas produzidas. Para tanto, foram formulados 22 substratos, os quais tiveram suas propriedades físicas e químicas avaliadas, sendo a semeadura realizada em tubetes de 120 cm³, acondicionados em casa de sombra, com irrigação controlada. Para a análise dos resultados, foram feitas avaliações de altura, diâmetro de colo, biomassa seca aérea e radicial, facilidade de retirada do tubete, agregação das raízes ao substrato, índice de qualidade de Dickson e relação altura e diâmetro de colo aos 180 dias. De acordo com os resultados obtidos, conclui-se que o melhor substrato testado foi o substrato comercial à base de casca de pinus. Os componentes renováveis, casca de arroz carbonizada, fibra de coco e substrato comercial à base de casca de pinus, apresentaram-se viáveis tecnicamente para produção de mudas de branquilho, enquanto que a casca de arroz carbonizada pura e vermiculita fina não apresentaram viabilidade. No que se refere às propriedades dos substratos, apenas a densidade aparente, pH, Ca e P apresentaram correlação com as variáveis biométricas das mudas. AbstractEffects of different substrates in production of Sebastiania commersoniana seedling. The aim of this research was to evaluate technical feasibility of using different substrates for production of seedlings of Sebastiania commersoniana and relate physical and chemical characteristics to the quality of the produced seedlings. In order to that, 22 substrates were formulated, with their physical and chemical properties evaluated, sowed in tubes of 120 cc, and put in shade, under controlled irrigation. For the results analysis, it evaluated height, stem diameter, air and radicial biomass, ease of removability, root aggregation to the substrate, Dickson quality index, and relation of height and diameter at 180 days. According to the obtained results, the best substrate tested was the commercial pine bark based substrate. The renewable components, carbonized rice hulls, coconut fiber, and commercial pine bark based substrate presented technical feasibility to produce Sebastiania commersoniana seedlings, on the other hand pure carbonized rice hulls and fine vermiculite did not. Towards the properties of the substrates, only bulk density, pH, Ca, and P correlated with biometric variables of the seedlings.Keywords: Branquilho; carbonized rice hulls; coconut fiber; pine bark; forest nursery.

scholarly journals The simplistic nitrogen input and output balance in Lake Łebsko – case study

2016 ◽  
Vol 45 (3) ◽  
Author(s):  
Roman Cieśliński
Keyword(s):  
Water Chemistry ◽  
Drainage Basin ◽  
Chemical Properties ◽  
Standard Pattern ◽  
Coastal Lakes ◽  
Lake Water Chemistry ◽  
Short Time ◽  
Physical And Chemical

AbstractThe paper is based on the hypothesis that coastal lakes significantly affect changes in the quality of freshwater coming from catchments, which is best reflected in the reduction of biogenic loads. Some of the main reasons for this phenomenon include unique geographic locations of coastal lakes and physical and chemical properties of their waters as well as other hydrographic determinants that affect water circulation in catchments. The study area covered the direct drainage basin of Lake Lebsko, which is located in Słowiński National Park in northern Poland, on the coast of the southern Baltic Sea. The study was conducted from June 2008 to October 2010. Fieldwork was the main part of the research project and included hydrographic mapping, water sampling for laboratory analysis, and measurement of the discharge in all tributaries and outflows of the studied lake. Water chemistry data for Lake Lebsko indicate a significant accumulation of biogenic materials in the lake, which proves a strong effect exerted by the lake on the incoming water. This is true for both total chemical loads per year as well as concentrations of selected ions over short time intervals. This standard pattern may be interrupted by seawater intrusions that alter water chemistry in the whole lake.

scholarly journals Vigor and Viability of Cagaita (Eugenia dysenterica DC.) Seeds Subjected to Different Substrates

2020 ◽  
pp. 52-56
Author(s):  
Helber Véras Nunes ◽  
Daniella Inácio Barros ◽  
João Pedro Pereira dos Santos ◽  
Kaio Rodrigues dos Santos de Oliveira ◽  
Bruna Azevedo Barbosa ◽  
...  
Keyword(s):  
Poultry Manure ◽  
Chemical Properties ◽  
Black Soil ◽  
Urban Region ◽  
Brazilian Cerrado ◽  
Federal Institute ◽  
Eugenia Dysenterica ◽  
Physical And Chemical ◽  
And Chemical Properties

Cagaita originates from the Brazilian Cerrado and belongs to the Myrtaceae family. It is a fruit tree and widely disseminated in the Brazilian Cerrado, and can reach up to 10 meters high. To obtain quality seedlings it is necessary to use substrates that have physical and chemical properties suitable for plant development. Also, the quality of the substrate is directly related to the proportions and the material that makes up the mixture. The experiment was conducted in a greenhouse at the Federal Institute of Education (IFTO), Science and Technology of Tocantins, Gurupi/TO city, from November 1, 2017, to February 26, 2018. Cagaita (Eugenia dysenterica DC.) seeds taken directly from the fruit were used to perform the experiment, which was collected in the urban region of Peixe - To in October 2017. Six types of substrates were used for the installation of the experiment, which was: Washed Sand; Washed Sand + Coconut Shell + Black Soil + Poultry Manure; Black Soil; Pine Bark + Poultry Manure + 25% Commercial Substrate Plantmax®; Earthworm Humus + Black Soil + 25% Commercial Substrate Plantmax®; 25% Commercial Substrate Plantmax® + Poultry Manure + Black soil + washed sand. The substrates of earthworm humus + Black Soil + 25% commercial substrate Plantmax® and 25% Commercial Substrate Plantmax® + Poultry Manure + Black Soil + Washed Sand provided the highest values of viability and vigor in Cagaita seeds.

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