scholarly journals Dependence between structure of cast Al-Ni-La alloys and their chemical composition

2021 ◽  
Vol 100 (4) ◽  
pp. 45-51
Author(s):  
M. M. Voron ◽  
Keyword(s):  
Chemical Composition ◽  
Structure Formation ◽  
Nickel Aluminide ◽  
Amorphous Materials ◽  
Structural Phase ◽  
Nickel Content ◽  
State Diagram ◽  
Cast Aluminum ◽  
Eutectic Concentration ◽  
Main Components

The peculiarities of cast Al-Ni-La alloys structure formation depending on the content and ratio of the main components are analyzed in the work. It is shown, that so far the studied system has been considered mainly for the creation of amorphous materials. At the same time, Al-Ni and Al-La systems have phase diagrams that allow us to consider double and triple alloys of these systems to create promising creep-resistant alloys for casting. At the same time, the peculiarities of their structure formation in this context were not determined. Samples with different contents of nickel and lanthanum were prepared for research and analyzed how each of the elements, their number and ratio affect the formation of their structural-phase state. It is shown, that low nickel content of about 2 wt. % and lanthanum up to 5 wt. % eutectic is formed like thin almost monolithic intermetallic plates. As the number of components increases and, accordingly, the number of eutectics increases, the dispersion of its components increases. The analysis of the alloy structure dependence due to studied system on their chemical composition showed that, most likely, during the formation of the eutectic, Al11La3 particles, which may have the form of nanosized fibers, are formed first of all. It should be noted that at the eutectic content of lanthanum in the alloys no primary-formed Al11La3 particles were found. This may indicate that nickel shifts the eutectic concentration of lanthanum toward higher values. At the same time, at the hypoeutectic concentration of lanthanum and the hypereutectic concentration of nickel, some Al11La3 formations were outside the regions of the main eutectic with nickel aluminide. Such questions necessitate further studies of the aluminum angle of the triple state diagram of the Al-Ni-La system. Keywords: Al-Ni-La system, creep-resistant cast aluminum alloys, structure, eutectic.

scholarly journals Avocado-Derived Biomass: Chemical Composition and Antioxidant Potential

Proceedings ◽  
2020 ◽  
Vol 70 (1) ◽  
pp. 100
Author(s):  
Minerva C. García-Vargas ◽  
María del Mar Contreras ◽  
Irene Gómez-Cruz ◽  
Juan Miguel Romero-García ◽  
Eulogio Castro
Keyword(s):  
Chemical Composition ◽  
Phenolic Content ◽  
Antioxidant Properties ◽  
Total Phenolic ◽  
Nutritional Properties ◽  
Aqueous Fraction ◽  
Extraction Solvent ◽  
Main Components ◽  
A Minor ◽  
Derivatives Of

Avocado has become fashionable due to its great organoleptic and nutritional properties. It is consumed as a fresh product and it is also processed to obtain salad oil and guacamole. In all cases, the only usable portion is the pulp. Therefore, to be a more sustainable and profitable agribusiness, it is important to recognize which compounds from the peel and the stone waste can be converted into valuable bio-products. Therefore, their chemical composition was determined according to the National Renewable Energy Laboratory, the total phenolic content by the Folin-Ciocalteu method and the antioxidant properties by the FRAP and TEAC assays. The main components of the peel and stone were acid-insoluble lignin (35.0% and 15.3%, respectively), polymeric sugars (23.6% and 43.9%, respectively), and the aqueous extractives (15.5% and 16.9%, respectively). Both biomasses contain lipids and protein, but a minor proportion (<6%). The valorization of lignin and sugars is of interest given the high content; stones are a rich source of glucose (93.2% of the polymeric fraction), which could be used to obtain biofuels or derivatives of interest. The extractive fraction of the peel contained the highest number of phenolic compounds (4.7 g/100 g biomass), mainly concentrated in the aqueous fraction (i.e., 87%) compared to the ethanol one, which was subsequently extracted. It correlated with major antioxidant activity and, therefore, the peel can be applied to obtain antioxidants and water can be used as an environmentally friendly extraction solvent.

Structure formation of cast aluminum-silicon alloy during thixotropic treatment

2021 ◽  
Author(s):  
Tat’yana Renatovna Gilmanshina ◽  
Aleksey Ivanovich Anikin ◽  
Angelina Adol’fovna Kovaleva ◽  
Svetlana Igorevna Lytkina ◽  
Sergey Aleksandrovich Khudonogov ◽  
...  
Keyword(s):  
Structure Formation ◽  
Cast Aluminum ◽  
Silicon Alloy ◽  
Aluminum Silicon Alloy ◽  
Aluminum Silicon

scholarly journals Variation of the Chemical Composition of Waste Cooking Oils upon Bentonite Filtration

Resources ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 108 ◽  
Author(s):  
Alberto Mannu ◽  
Gina Vlahopoulou ◽  
Paolo Urgeghe ◽  
Monica Ferro ◽  
Alessandra Del Caro ◽  
...  
Keyword(s):  
Particle Size ◽  
Chemical Composition ◽  
Solid Phase ◽  
Volatile Fraction ◽  
X Ray Diffraction ◽  
Specific Chemical ◽  
Waste Cooking Oils ◽  
Main Components ◽  
Cooking Oils ◽  
Chemical Groups

The chemical composition and the color of samples of waste cooking oils (WCOs) were determined prior to and after filtration on two different pads of bentonite differing in particle size. The volatile fraction was monitored by headspace solid-phase microextraction (HS-SPME) coupled with gas-chromatography, while the variation of the composition of the main components was analyzed by 1H NMR. Both techniques allowed the detection of some decomposition products, such as polymers, terpenes, and derivatives of the Maillard process. The analysis of the chemical composition prior to and after bentonite treatment revealed a tendency for the clays to retain specific chemical groups (such as carboxylic acids or double bonds), independent of their particle size. A pair comparison test was conducted in order to detect the sensory differences of the intensity of aroma between the WCO treated with the two different bentonites. In addition, characterization of the bentonite by means of powder X-ray diffraction (XRD) and thermogravimetric measurements (TG) was performed.

scholarly journals Chemical Composition and Antimicrobial Activity of the Essential Oil from Flowers of Eryngium triquetrum (Apiaceae) Collected Wild in Sicily

2016 ◽  
Vol 11 (7) ◽  
pp. 1934578X1601100
Author(s):  
Simona Casiglia ◽  
Maurizio Bruno ◽  
Sergio Rosselli ◽  
Felice Senatore
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Antifungal Activities ◽  
Antibacterial And Antifungal Activities ◽  
Art Works ◽  
Main Components ◽  
Antibacterial And Antifungal ◽  
Historical Art

The chemical composition of the essential oil from flowers of Eringium triquetrum Vahl. collected in Sicily was evaluated by GC and GC-MS. The main components were pulegone (50.6%), piperitenone (30.5%) and menthone (7.0%). Comparison of this oil with other studied oils of Eringium species is discussed. The oil showed good antibacterial and antifungal activities against some microorganisms that infest historical art works.

Elaboration of weatherproof steel 06гн3мд for structures of bridges exploited in coastal zone

2021 ◽  
Vol 77 (7) ◽  
pp. 811-819
Author(s):  
G. A. Kunitsin ◽  
А. А. Pridein ◽  
O. V. Samokhina ◽  
D. V. Nizhel’skii ◽  
E. M. Gitman
Keyword(s):  
Corrosion Resistance ◽  
Chemical Composition ◽  
Nickel Content ◽  
Research Work ◽  
Steel Structures ◽  
Surface Cleaning ◽  
Protective Film ◽  
Laboratory Studies ◽  
Specific Chemical ◽  
Climate Conditions

At present decreasing of costs and increasing of efficiency are the most priority directions in any industry. Developing in this way, JSC “Ural steel” together with FGUP “CNIIchermet after I.P. Barding” had mastered production of sheet metal product with increased resistivity against atmosphere corrosion made of steel 14ХГНДЦ for construction of bridges. Because of specific chemical composition of the steel, in the process of metal structures running in the open air, a solid strong oxide film is formed on the metal of the structures which prevents further corrosion without painting. For bridge builders elimination of costly operation of painting of span structures will enable to decrease considerably the costs of bridges construction and running. Having many advantages, steel 14ХГНДЦ has some restrictions in applications for steel structures without painting, as follows: - in sea zone according to domestic norms no close than 500 m from coastline; - in case of disorderly conditions of protective film formation and/or application of salt solutions for surface cleaning (as a rule the restrictions refer to traffic area of bridge span). In view of that for JSC “Ural Steel”, as the leading producer of bridge steel in Russia, an actual task erose: to elaborate and create a weatherproof steel, which could not only operate the whole period of a bridge running without additional protection at bridges con­struction through sea areas or close to coastline, but also withstand severe climate conditions of our country, including areas of High North with temperature lower -50°С. To solve the task together with OJSC “Institute Giprostroymost” and JSC BNIIZhT, a research work was accomplished to elaborate a system of alloying new steel 06ГН3МД with nickel content ~3.0 %, as well as production modes ensuring required corrosion resistance for operation in sea zone. Results of laboratory studies of the new weatherproof steel 06ГН3МД for application in bridge  structures for coastal conditions and sea areas presented. Results of mechanical, technological, corrosion as well as fatigue tests of rolling products of the elaborated steel presented. It was established by laboratory studies that the new steel is weatherproofed and ensures lower corrosion losses, higher impact toughness at negative temperatures and plasticity comparing with steels used at present. It was shown that the strength class, technology and modes of factory welding of steel 06ГН3МД meet the  requirements to steel span structures of bridges. Base on the results of the studies, the chemical composition of the steel 06ГН3МД was specified, as well as modes of heat treatment, ensuring the required characteristics with significant acceding. It was established that samples of the new steel 06ГН3МД showed considerably higher corrosion resistance - in average by 20% comparing with steel 14ХГНДЦ. At that corrosion resistance tests of welded joints of the new steel showed even higher resistance of the seam comparing with the basic metal, which speaks about quality selection of welding modes and welding materials.

Research on causes of hot-tearing of AA3003 aluminum billet during DC casting process

2021 ◽  
Vol 95 ◽  
pp. 29-37
Author(s):  
Bach Dao Hong ◽  
◽  
Trung Trinh Van
Keyword(s):  
Chemical Composition ◽  
Casting Process ◽  
Direct Chill ◽  
Hot Tearing ◽  
Cast Aluminum ◽  
Allowable Limit ◽  
Chemical Composition Distribution ◽  
Electron Microscopes ◽  
Scanning Electron Microscopes ◽  
Direct Chill Casting Process

AA3003 aluminum alloy made from raw scrap materials that have the advantage of economical use, but hottearing often occurs in the product billets of the direct chill casting process. This study used ANOVA analysis method for determination of chemical composition of AA3003 aluminum billet products to show influence of chemical composition on hot-tearing ability. The evaluation of the microstructure and chemical composition distribution of the elements by optical and scanning electron microscopes combined with energy dispersive spectroscopy showed the existence of impurities such as Cu, Zn, Fe, Pb exceeding the allowable limit in aluminum billets, especially at grain boundary, which can be the main reason for the hot-tearing of cast aluminum billets.

scholarly journals Comparison of the Chemical Composition and Antimicrobial Activity of Thymus serpyllum Essential Oils

2015 ◽  
Vol 43 (2) ◽  
pp. 432-438 ◽  
Author(s):  
Aneta WESOŁOWSKA ◽  
Monika GRZESZCZUK ◽  
Dorota JADCZAK ◽  
Paweł NAWROTEK ◽  
Magdalena STRUK
Keyword(s):  
Antimicrobial Activity ◽  
Chemical Composition ◽  
Essential Oil ◽  
Essential Oils ◽  
Micrococcus Luteus ◽  
Gas Chromatography Mass Spectrometry ◽  
E Coli ◽  
Thymus Serpyllum ◽  
Main Components ◽  
Total Oil

The chemical composition of the essential oils obtained by hydrodistillation from the aerial parts of Thymus serpyllum and Thymus serpyllum‘Aureus’ has been investigated by gas chromatography-mass spectrometry (GC-MS). Forty-seven compounds (99.67% of the total oil) wereidentified in the essential oil of T. serpyllum. The main components found in the oil were carvacrol (37.49%), -terpinene (10.79%), -caryophyllene (6.51%), p-cymene (6.06%), (E)--ocimene (4.63%) and -bisabolene (4.51%). Similarly, carvacrol (44.93%), -terpinene(10.08%), p-cymene (7.39%) and -caryophyllene (6.77%) dominated in the oil of T. serpyllum ‘Aureus’. A total of forty three compounds wereidentified in this oil, representing 99.49% of the total oil content. On the basis of the obtained data it was proved that the content of 1-octen-3-ol,eucalyptol, (Z)--ocimene, (E)--ocimene, -terpinene, carvacrol methyl ether, germacrene D and -bisabolene was significantly higher for T.serpyllum while T. serpyllum ‘Aureus’ was characterized by a significantly higher content of 3-octanone, 3-octanol, p-cymene, borneol andcarvacrol. The isolated essential oils were evaluated for their antimicrobial activity against nine reference strains (Escherichia coli, Staphylococcusaureus, Staphylococcus epidermidis, Streptococcus agalactiae, Enterococcus faecalis, Bacillus cereus, Micrococcus luteus, Proteus vulgaris and Candidaalbicans) by the microdilution technique. Based on this test, the minimum inhibitory concentrations (MIC) of essential oil were calculated. Thevolatile oil obtained from T. serpyllum showed the highest antimicrobial activity relative to the strain of E. coli (MIC=0.025 μL/mL) and to theyeast C. albicans (MIC=0.05 μL/mL). Similarly, a significant antimicrobial activity exhibited T. serpyllum ‘Aureus’ essential oil, although the MICvalues obtained in that case for E. coli and C. albicans strains were twice as high and were respectively 0.05 μL/mL and 0.1 μL/mL.

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