Substrate Selection by Tubificid Oligochaetes

1983 ◽  
Vol 40 (10) ◽  
pp. 1639-1646 ◽  
Author(s):  
M. J. McMurtry ◽  
D. J. Rapport ◽  
K. E. Chua
Keyword(s):  
Chemical Elements ◽  
Chemical Properties ◽  
Organic Content ◽  
Tubifex Tubifex ◽  
Aerobic Bacteria ◽  
Substrate Selection ◽  
Limnodrilus Hoffmeisteri ◽  
Selection Experiments ◽  
Physical And Chemical ◽  
And Chemical Properties

Groups composed of Tubifex tubifex and Limnodrilus hoffmeisteri collected from Keating Channel and Hanlan's Point in Toronto Harbor, Lake Ontario, preferred Keating Channel sediment over Hanlan's Point sediment in laboratory substrate selection experiments. The degree of preference did not differ between the two species. Substrate selection appears to be a taxic response to dispersing microbiota or molecules with molecular weight greater than 12 000–14 000. Percent organic content, concentrations of selected chemical elements and particle size do not account for the observed preference. However, there was a significant correlation between the abundance of heterotrophic aerobic bacteria in sediment and tubificid preference. We suggest that the microbial constituents of the sediment are more important than its physical and chemical properties in influencing substrate selection by tubificids.

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 Post-pyrogenic changes in the properties of grey forest podzolic soils of ecogeosystems of pine forests under conditions of anthropogenicloading

2018 ◽  
Vol 27 (2) ◽  
pp. 175-183 ◽  
Author(s):  
V. Asotskyi ◽  
Y. Buts ◽  
O. Kraynyuk ◽  
R. Ponomarenko
Keyword(s):  
Chemical Composition ◽  
Chemical Elements ◽  
Chemical Properties ◽  
Heavy Metal Concentration ◽  
Forest Litter ◽  
Negative Influence ◽  
Exchange Cations ◽  
Chemical Properties Of Soils ◽  
Physical And Chemical ◽  
And Chemical Properties

This article presents the analysis of results of experimental data of postpyrogenic change of soils of ecological systems of pine forests.Ground fires transform the surface organogenic horizons of soils. The negative influence of low-intensity fires of different intensity on the change of humus stock, qualitative fractional composition of organogenic soil horizons and their chemical composition is shown.Post-pyrogenic transformations of physical and chemical soil characteristics are found, which are not simply their corresponding reaction to the pyrogenic effect, but a clear signal reflecting the state of the soil immediately after the fire, taking into account its strength and intensity, and after a certain period of time. There is a certain dependence of the degree of pyrogenicity on the duration of the effect of fire on the soil. The recent influence of a medium intensity fire on the soil is marked by a clear reaction of the complex of its properties.Physical and chemical properties of soils after fires deteriorate: humus burns, the content of nitrate nitrogen decreases.Forest fires sharply change the morphological state of the upper part of the soil profile. The nature of the surface horizons of soils changes, a new pyrogenic horizon is formed, which differs from natural analogues in terms of physical and chemical properties and the content of ash elements. Under the influence of fire there are changes in such properties as: pH, content of exchange cations, gross and moving forms of nitrogen, etc.The heavy metal concentration in surface horizons increases several times and exceeds the background values due to the mineralization of forest litter and herbaceous vegetation from the combustion and subsequent migration of chemical elements , which presents an environmental hazard.The change in the chemical composition of soils can create conditions for the impossibility of the existence of a root ecosystem, its death, and development, after a certain time, of another modified ecogeosystem.

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.

Modification of Etching Patterns in Bovine Dental Enamel

1979 ◽  
Vol 58 (8) ◽  
pp. 1840-1847 ◽  
Author(s):  
S. Lees ◽  
P.L. Trombly ◽  
Z. Skobe ◽  
E.E. Gariepy ◽  
A.F. Trull
Keyword(s):  
Organic Material ◽  
Chemical Properties ◽  
Dental Enamel ◽  
Organic Content ◽  
Tooth Surface ◽  
Physical And Chemical Properties ◽  
Etching Pattern ◽  
Naoh Solution ◽  
Physical And Chemical ◽  
And Chemical Properties

It is presumed that the etching pattern is controlled by the residual organic content of dental enamel. Pretreatment with 1.ON NaOH should remove the organic material and modify the etching pattern. SEM studies and other tests for physical and chemical properties show that the predicted modification of the etching pattern, when the tooth surface is pretreated with NaOH solution, occurs apparently without other changes of properties.

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.

scholarly journals Eco-Friendly Preparation and Characterization of Bioplastic Films from Marine Fish Wastes

2021 ◽  
Author(s):  
Parthasarathy Surya ◽  
Sundaramanickam Arumugam ◽  
Ajith Nithin ◽  
Parthasarathy Iswarya
Keyword(s):  
Corn Starch ◽  
Chemical Properties ◽  
Organic Content ◽  
Hot Water ◽  
Fish Scale ◽  
Casting Technique ◽  
Physical And Chemical ◽  
And Chemical Properties ◽  
Surface Changes

Abstract Synthetic plastics are highly hazardous contaminants; hence they must be replaced with alternatives. This study aimed to prepare corn starch-based bioplastics using fish scale through film casting technique as an alternative to synthetic plastics. In this work, four types of bioplastic films containing different percentages of fish-scale powder and corn starch were prepared. Physical and chemical properties such as texture, color, solubility in hot water, tensile strength, organic content, and morphology of all the four types of the synthesized biopolymer were analyzed. The mixture of fish-scale powder and corn-flour powder in the ratio of 1: 3 yielded the best results. In the biodegradability test, degradation was noticed after 7 days of treatment with organic waste. The degradation was confirmed by surface changes in the morphology and the development of Aspergillus sp. The produced bioplastics were synthesized from eco-friendly, inexpensive, and natural materials. Thus, the present research has provided a viable alternative to synthetic plastics.

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.

Synthesis and Characterization of Zn doped Li(Li0.21Mn0.54Ni0.125Co0.125)O2 as the Layer Materials For Battery Applications

2018 ◽  
Vol 21 (2) ◽  
pp. 127-131
Author(s):  
S. Rumh. Kadhim ◽  
Reihan Etefagh ◽  
H. Arabi
Keyword(s):  
Infrared Spectroscopy ◽  
Chemical Elements ◽  
Sol Gel ◽  
Chemical Properties ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Physical And Chemical ◽  
And Chemical Properties

In this paper, pure and impure nanopowders of Li(Li0.021Mn0.54Ni0.125Co0.125)O2 were prepared with different percentages (x=0.02%, 0.05%, 0.075%, 0.10%) of Zn impurity by sol-gel method, and the effect of different percentages were investigated on the structural, physical and chemical properties of the samples. These properties of samples characterized by X-ray diffraction (XRD), field-scattering microscopy (FESEM), X-ray energy spectroscopy (EDS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), differential thermal analysis (DTA), infrared spectroscopy (FTIR), and the results of characterization were investigation. All the reflection peaks indicate that the samples have standard α-NaFeO2 layered structure with the space group R3m, except for the super lattice ordering between 22°-25°.The FESEM images have shown that these nanoparticles have Hexagonal structures for doped and undoped nanopowders. The particle size of nanopowders in the range of 30-80 nm the chemical analysis of EDS has proven the presence of Zn in the samples. TG /DTA measurements showed weight loss in pure and impure of nanopowders. In infrared spectroscopy (FTIR), the connection bonds and chemical elements used in these nanopowders have been investigated.

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.

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