Research of Mo Powder’s Densification during Sintering

2011 ◽  
Vol 399-401 ◽  
pp. 103-108
Author(s):  
Ren Zhi Liu ◽  
Kuai She Wang ◽  
Yuan Jun Sun
Keyword(s):  
Sintering Temperature ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Cold Isostatic Pressing ◽  
Physical And Chemical Properties ◽  
Fracture Surface Morphology ◽  
Shrinkage Ratio ◽  
Physical And Chemical ◽  
Sintering Shrinkage ◽  
And Chemical Properties

Mo powder was pressed into rods by cold isostatic pressing and sintered by multi-function furnace. Physical and chemical properties of sintering samples at different temperature were tested such as chemical elements, density, area shrinkage ratio and fracture surface morphology. Through the investigation we can draw the conclusions as following: Mo powder softens at 1353K. The temperature of beginning metallization is 1833K. In the range of 1713K~1953K, impurity contents such as C and O drop down fast and density increases sharply. When sintering temperature rises from 1833K to 1953K, the grains of sintering rods are fine. When the sintering temperature surpasses 2073K, the grains grow up very fast. The sintering shrinkage ratio enlarges quickly.

Microporous Ceramics Made by Silicon Carbide Whiskers

2007 ◽  
Vol 336-338 ◽  
pp. 1904-1905
Author(s):  
Chang Hong Dai ◽  
Ru Zhao ◽  
Li Shui ◽  
Bao Bao Zhang
Keyword(s):  
Silicon Carbide ◽  
Flexural Strength ◽  
Pore Size ◽  
Sintering Temperature ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Sintering Aids ◽  
Silicon Carbide Whiskers ◽  
Physical And Chemical ◽  
And Chemical Properties

A new method for preparing microporous ceramics by the silicon carbide whiskers was studied in this paper. The physical and chemical properties and the microstructure of the microporous ceramics were tested, while some influencing factors for the product, such as the amount of sintering aids and sintering temperature, were discussed. The results suggest that the apparent porosity of the microporous ceramics is 55.7-59.8% and the flexural strength is 127-176MPa. The pore distribution of the microporous ceramics is uniformity and the diameter of the pore ranges between 0.5μm and 7μm. The porosity and pore size of the microporous ceramic can be controlled by adjusting the sintering temperature and the amount of sintering aids.

scholarly journals MgO Refractory Doped with ZrO2 Nanoparticles: Influence of Cold Isostatic and Uniaxial Pressing and Sintering Temperature in the Physical and Chemical Properties

Metals ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 1297 ◽  
Author(s):  
Cristian Gómez-Rodríguez ◽  
Daniel Fernández-González ◽  
Linda Viviana García-Quiñonez ◽  
Guadalupe Alan Castillo-Rodríguez ◽  
Josué Amilcar Aguilar-Martínez ◽  
...  
Keyword(s):  
Chemical Properties ◽  
Cold Isostatic Pressing ◽  
Zro2 Nanoparticles ◽  
Furnace Lining ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Isostatic Pressing ◽  
Physical And Chemical ◽  
The Impact ◽  
And Chemical Properties

The chemical environment and the internal conditions of the furnaces and ladles are extremely aggressive for the refractories, so metallurgical industries demand refractory linings with greater durability and resistance to avoid unforeseen stoppages and to reduce the changes of the furnace lining. Therefore, the current work aims to evaluate the impact of the additions of ZrO2-nanoparticles (1, 3, and 5 wt. %) in magnesia-based bricks. A comparative study of the physical and chemical properties in bricks obtained using two cold pressing techniques (uniaxial and isostatic pressing) and two sintering temperatures (1550 and 1650 °C) was carried out. The microstructure and crystalline phase characteristics obtained after the heat treatments and the slag corrosion test was studied using scanning electron microscopy/electron dispersive X-ray spectroscopy (SEM/EDX) and X-ray diffraction (XRD). The results reveal that the sample with 5 wt. % of ZrO2 nanoparticles (obtained by cold isostatic pressing and sintering at 1650 °C) has the lowest porosity and greatest resistance to penetration of blast furnace slag.

scholarly journals Changes of soils properties in the process of spontaneous afforestation of arable land in the territory of the Upper Dnister Beskid (Ukrainian Carpathians)

2017 ◽  
pp. 382-389
Author(s):  
Iryna Shpakivska ◽  
Ivanna Storozhuk
Keyword(s):  
Organic Matter ◽  
Chemical Elements ◽  
Arable Land ◽  
Chemical Properties ◽  
Physical And Chemical Properties ◽  
Closed Forest ◽  
Actual Acidity ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Hydrolytic Acidity

The peculiarities soil transformation of stages of the spontaneous afforestation in the Upper Dnister Beskid region were evaluated. The afforestation ecosystems represented series of restoration succession of forest ecosystems: arable land → ruderal stage → grassland stage → shrub stage → closed forest. The changes of the basic physical and chemical properties of the brown soils of the Upper Dniester Beskid of different stages of the afforestation within the transect of v. Gvozdenec and v. Topilnytca (Starosambirsky district of the Lviv region) were investigated. It was established that the process of spontaneous afforestation of arable land on the territory of the Upper Dniester Beskid causes an increase in actual, potential and hydrolytic acidity in the direction from the arable land to the closed forest, as well as an increase in the amount of organic matter in the forest soils compared with the arable land. Want of agricultural cultivation of the territory and the process of spontaneous afforestation an increase in the content of organic acids and salts, in particular carbon (H2CO3), in the upper horizons of the soil, which leads to changes in the actual acidity in the soil profi le. In the direction from the arable land to the closed forest there are increases in the actual acidity. Spontaneous afforestation, especially due to coniferous trees, causes a change in the amount of hydrogen and aluminum in the soil solution. The upper humus horizons had higher hydrolytic acidity than humus transitions horizons, which is related plants fall on the soil surface and the redistribution of chemical elements in the soil profile. In post-arable soils, the amount of organic carbon increases due to want of organic fertilization with the economic part of the crops and its annual input from plant fallout. It was established that the arable plots content of organic matter is 2,97–3,32 % in forest areas – 4,02–4,30 %. Key words: brown soils, physical and chemical properties, afforestation, Upper Dnister Beskid.

scholarly journals SIFAT FISIKA DAN KIMIA TANAH PADA LAHAN HUTAN GAMBUT BEKAS TERBAKAR: STUDI KASUS KABUPATEN OGAN KOMERING ILIRSUMATERA SELATAN, INDONESIA PHYSICAL AND CHEMICAL PROPERTIES OF BURNT PEAT LAND FOREST: CASE STUDY IN OGAN KOMERING ILIR REGENCY, SOUTH SUMATRA, INDONESIA

2019 ◽  
Vol 8 (1) ◽  
pp. 1
Author(s):  
Lulu Yuningsih ◽  
Bastoni Bastoni ◽  
Taty Yulianty ◽  
Jun Harbi
Keyword(s):  
Bulk Density ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Germplasm Conservation ◽  
Physical And Chemical Properties ◽  
Comprehensive Information ◽  
Significant Difference ◽  
Physical And Chemical ◽  
Properties Of Soil ◽  
And Chemical Properties

Kebakaran di hutan gambut telah mengubah karakteristik lahan tersebut. Ironisnya, saat ini perhatian berupa riset terhadap sifat fisik dan kimia lahan gambut yang mengalami perubahan tersebut masih sangat rendah. Padahal sifat fisik dan kimia gambut merupakan faktor penting yang mempengaruhi kemampuan tanah untuk berproses. Sehingga tujuan dari penelitian ini adalah untuk kondisi fisik dan kimia tanah pada lahan gambut pasca kebakaran tahun 2006 dan 2015. Studi ini dilakukan pada tahun 2017 di Kebun Konservasi Plasma Nutfah, Indonesia dan analisis dilakukan di Laboratorium Ilmu Tanah, Universitas Sriwijaya dan Balai Riset Standarisasi Industri Palembang (Baristand). Berdasarkan analisis uji lanjutan Beda Nyata Jujur (BNJ) pada sifat fisika tanah menunjukkan bahwa ada perbedaan nyata terhadap perubahan kadar air dan bulk density di lahan pasca terbakar tahun 2015 dan lahan pasca terbakar tahun 2006 yang sudah dilakukan kegiatan rehabilitasi. Pada sifat kimia, pH, C-Organik, Phospor, dan Kalium menunjukkan adanya perubahan nyata terhadap kebakaran di lahan gambut pasca terbakar tahun 2006 dan di lahan gambut pasca terbakar tahun 2015, akan tetapi terhadap N-total adanya perubahan akan tetapi tidak terlalu nyata di kedua lokasi. Masih dibutuhkan informasi lebih komprehensif terhadap unsur fisika dan kimia lainnya serta  sifat biologi tanah sehingga dapat menjadi acuan yang lebih presisi. Fires in peat forests have changed the characteristics of the land. Ironically, current attention includes research on the physical and chemical properties of peatlands that have changed is still scarce. Though the physical and chemical properties of peatlands is an essential factor affecting the ability of the soil to process. So, the purpose of this research is to analyze the physical and chemical properties of soil on peatlands after burning in 2006 and 2015. This study was conducted in 2017 at the Kebun Konservasi Plasma Nutfah (Germplasm Conservation Garden), Indonesia and analysis were carried out at the Soil Science Laboratory, Sriwijaya University and the Palembang Industrial Standardization Research Center (Baristand). Based on further analysis of Honest Significant Difference (BNJ) on the physical properties of soil shows that there are significant differences in changes of water content and bulk density in post-burnt land in 2015 and post-burnt land in 2006 that have been carried out rehabilitation activities. In the analysis of chemical properties consisting of analysis of pH, C-Organic, Phosphor, and Potassium showed a real change in fires in peatlands after burning in 2006 and peatlands after burning in 2015. However, at the N-total values, changes occurred but not too real in both locations. More comprehensive information is still needed on other physical and chemical elements as well as soil biological characteristics so that they can become more precise references.

Atomic Structure and Isotopes

2009 ◽  
Author(s):  
Christopher O. Oriakhi
Keyword(s):  
Chemical Elements ◽  
Chemical Properties ◽  
Central Nucleus ◽  
Physical And Chemical Properties ◽  
Whole Numbers ◽  
The Law ◽  
Simple Ratio ◽  
A Charge ◽  
Physical And Chemical ◽  
And Chemical Properties

John Dalton proposed his theory of the atom in 1808 based on experimental data and chemical laws known in his day. The theory states that: 1. All chemical elements are made up of tiny indivisible particles called atoms. 2. Atoms cannot be created or destroyed. Chemical reactions only rearrange the manner in which atoms are combined. 3. Atoms of the same element are identical in all respects and have the same masses and physical and chemical properties. Atoms of different elements have different masses as well as different physical and chemical properties. 4. Combination of elements to form a compound occurs between small, whole-number ratios of atoms. Dalton’s theory resulted in the formulation of the law of conservation of mass and the law of multiple proportions. In a chemical reaction matter is neither created nor destroyed. The mass of products is equal to the mass of the reactants. If two elements form more than one compound between them, the masses of one element that combine with a fixed mass of the second element are in a ratio of whole numbers. Nitrogen and oxygen combine to form different compounds such as NO, NO2, and N2O. According to this law the number of nitrogen to oxygen atoms in these compounds should be a simple ratio of two small whole numbers. This is one of the basic laws of stoichiometry, as we shall see in chapter 9. An atom consists of a central nucleus, which contains roughly 99.9% of the total mass of the atom, and a surrounding cloud of electrons. The nucleus is composed of two kinds of particles, the protons and the neutrons, which are collectively known as the nucleons. The proton is positively charged while the neutron is electrically neutral. The electrons have a negative charge and surround the nucleus in “shells” of definite energy levels. (Note: energy level will be discussed in chapter 10.) In a neutral (unreacted) atom, the number of electrons is equal to the number of protons, so the atom has a charge of zero.

scholarly journals Characteristics of Lateritic Nickel Mineralization In Mid Part of Madang and Serakaman Areas, Sebuku Island, South Kalimantan

2018 ◽  
Vol 159 ◽  
pp. 01038
Author(s):  
Yoga Aribowo ◽  
Yudi Syahputra ◽  
Dian Agus Widiarso
Keyword(s):  
Chemical Elements ◽  
Chemical Properties ◽  
Geological Mapping ◽  
Drill Core ◽  
Physical And Chemical Properties ◽  
X Ray ◽  
Xrf Analysis ◽  
Lateritic Nickel ◽  
Physical And Chemical ◽  
And Chemical Properties

The research was conducted in Madang and Serakaman Tengah area, Sebuku Island Subdistrict, Kotabaru Regency, South Kalimantan Province which is one of the nickel potential areas in Indonesia. The aim of this research is to know the characteristic and distribution of laterite nickel mineralization. The rocks present in the study area are serpentinized dunite, serpentinized harzburgite, gabbro, silicified gabbro, tuff, and basalt. Methods used in this research were surface geological mapping, rock observation and sampling from outcrop and drill core representing each laterite horizon from limonite horizon to bedrock. Laboratory analysis consist of X-Ray Fluorescene (XRF) analysis is used to determine the abundance of certain chemical elements and compound which characterized the mineralization stage zonation in the laterite profile. The laterite deposite in the study area can be divided based on physical and chemical properties into four zones; red limonite, yellow limonite, saprolite, and bedrock. Saprolite is dominated by a group of hydrocylicic minerals (serpentine) so it can be predicted that the laterite types are developing laterite oxide and laterite silicate types.

Statistical criteria of stellar population types

1966 ◽  
Vol 24 ◽  
pp. 101-110
Author(s):  
W. Iwanowska
Keyword(s):  
Stellar Population ◽  
Chemical Properties ◽  
Spectrophotometric Study ◽  
Physical And Chemical Properties ◽  
Population Type ◽  
The Galaxy ◽  
Distribution Parameters ◽  
Physical And Chemical ◽  
Statistical Criteria ◽  
And Chemical Properties

In connection with the spectrophotometric study of population-type characteristics of various kinds of stars, a statistical analysis of kinematical and distribution parameters of the same stars is performed at the Toruń Observatory. This has a twofold purpose: first, to provide a practical guide in selecting stars for observing programmes, second, to contribute to the understanding of relations existing between the physical and chemical properties of stars and their kinematics and distribution in the Galaxy.

Response of corn (Zea mays L.) to various organic-based fertilizers in marginal upland of Sta. Rita, Samar

2017 ◽  
pp. 31-43
Author(s):  
Berta Ratilla ◽  
Loreme Cagande ◽  
Othello Capuno
Keyword(s):  
Block Design ◽  
Management Strategies ◽  
Chemical Properties ◽  
Organic Fertilizers ◽  
Growth And Yield ◽  
Physical And Chemical Properties ◽  
Total N ◽  
Randomized Complete Block Design ◽  
Physical And Chemical ◽  
And Chemical Properties

Organic farming is one of the management strategies that improve productivity of marginal uplands. The study aimed to: (1) evaluate effects of various organic-based fertilizers on the growth and yield of corn; (2) determine the appropriate combination for optimum yield; and (3) assess changes on the soil physical and chemical properties. Experiment was laid out in Randomized Complete Block Design, with 3 replications and 7 treatments, namely; T0=(0-0-0); T1=1t ha-1 Evans + 45-30-30kg N, P2O5, K2O ha-1; T2=t ha-1 Wellgrow + 45-30-30kg N, P2O5, K2O ha-1; T3=15t ha-1 chicken dung; T4=10t ha-1 chicken dung + 45-30-30kg N, P2O5, K2O ha-1; T5=15t ha-1 Vermicast; and T6=10t ha-1 Vermicast + 45-30-30kg N, P2O5, K2O ha-1. Application of organic-based fertilizers with or without inorganic fertilizers promoted growth of corn than the control. But due to high infestation of corn silk beetle(Monolepta bifasciata Horns), its grain yield was greatly affected. In the second cropping, except for Evans, any of these fertilizers applied alone or combined with 45-30-30kg N, P2O5, K2O ha-1 appeared appropriate in increasing corn earyield. Soil physical and chemical properties changed with addition of organic fertilizers. While bulk density decreased irrespective of treatments, pH, total N, available P and exchangeable K generally increased more with chicken dung application.

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