BACTERIAL DECOMPOSITION PROCESSES IN LAKE WINGRA SEDIMENTS DURING WINTER1

1973 ◽  
Vol 18 (4) ◽  
pp. 628-634 ◽  
Author(s):  
Charles Boylen ◽  
Thomas D. Brock
Keyword(s):  
Decomposition Processes ◽  
Bacterial Decomposition

Spontaneous Coagulation of Rubber Latex

1939 ◽  
Vol 12 (3) ◽  
pp. 469-469
Author(s):  
Paul Stamberger
Keyword(s):  
Contact Resistance ◽  
Hevea Brasiliensis ◽  
Gel Formation ◽  
Conductivity Measurements ◽  
Rubber Latex ◽  
Decomposition Processes ◽  
Bacterial Decomposition ◽  
Conductivity Cell ◽  
Serum Components

Abstract As early as 1913, Whitby advanced the view that spontaneous coagulation in rubber latex takes place before decomposition processes begin. Arguments against this view have since been advanced by several investigators, and the opinion generally held at present is that the coagulation of fresh latex is caused by formation of acid from the bacterial decomposition of the serum components. Recent investigations made on latex of Hevea brasiliensis have provided confirmation of the view held by Whitby. Experiments were conducted throughout on latex obtained immediately after collection from the trees, which had been tapped three or four hours previously. The formation of ions from decomposition of latex was followed by conductivity measurements. The conductivity of latex did not change until coagulation was complete. This occurred 6–11 hours after collection of the latex, varying from sample to sample. The resistance of the conductivity cell increased after gel formation, due to contact resistance on the electrodes.

The Chemistry Decomposition in Human Corpses

2017 ◽  
Vol 68 (6) ◽  
pp. 1352-1356 ◽  
Author(s):  
Beatrice Gabriela Ioan ◽  
Cristiana Manea ◽  
Bianca Hanganu ◽  
Laura Statescu ◽  
Laura Gheuca Solovastru ◽  
...  
Keyword(s):  
Chemical Compounds ◽  
Human Remains ◽  
Organic Substances ◽  
Chemical Decomposition ◽  
Factors Influencing ◽  
Human Decomposition ◽  
Decomposition Processes ◽  
Human Cadavers ◽  
The Subject ◽  
Decomposition Stages

Human body is a complex of organic substances (proteins, lipids, carbohydrates), which undergo chemical decomposition processes soon after death. The compounds released during decomposition characterize the development of different stages of this process: e.g. biogenic amines resulted from the proteins decomposition will confer the particular smell of a cadaver, gases resulted from carbohydrates fermentation will give the bloating aspect of the cadaver. The study of cadaver decomposition and the products resulted from this process is the subject of human taphonomy and is realized nowadays in special facilities in USA and Australia. Identification and analysis of the chemical compounds emerged after human decomposition (gases, liquids, salts) give valuable information to forensic pathologists for estimating the postmortem interval (PMI). More, volatile compounds � which give the odor signature�specific to human remains � may be utilized in identifying clandestine burials, human remains or victims entrapped under ruins in cases of natural disasters. In this paper the authors describe the chemical decomposition stages of human cadavers, the factors influencing these processes and utility for the forensic activity of the results of human taphonomic studies.

A Thorough Investigation of Photo-catalytic Degradation of ortho and para-Nitro Phenols in binary mixtures: New Insights into Evaluating Degradations Progress Using Chemometrics Approaches

2021 ◽  
Author(s):  
S. Maryam Sajjadi ◽  
Zeinab Asadollah-pour ◽  
S. Hashem Sajjadi ◽  
S. Nasrin Nabavi ◽  
Zahra Abed ◽  
...  
Keyword(s):  
Binary Mixtures ◽  
Zno Nanoparticles ◽  
Catalytic Degradation ◽  
Solar Irradiation ◽  
Photo Catalyst ◽  
Decomposition Processes ◽  
Simulated Solar Irradiation ◽  
Photo Decomposition

In this study, photocatalytic degradations of 2-nitrophenol and 4-nitrophenol were carried out efficiently using ZnO nanoparticles photo-catalyst under simulated solar irradiation. The photo-decomposition processes were optimized simultaneously by employing central...

scholarly journals Anion Coordination Improves High-Temperature Performance and Stability of NaPF6-Based Electrolytes for Supercapacitors

Energies ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4409
Author(s):  
J. Landon Tyler ◽  
Robert L. Sacci ◽  
Jagjit Nanda
Keyword(s):  
Thermal Stability ◽  
Electrolyte Solution ◽  
Elevated Temperatures ◽  
Electrochemical Impedance ◽  
Cycle Life ◽  
Stable Complex ◽  
Complexing Agents ◽  
Anion Coordination ◽  
Decomposition Processes ◽  
Hexamethyl Phosphoramide

Electrolyte stability can be improved by incorporating complexing agents that bind key decomposition intermediates and slow down decomposition. We show that hexamethyl-phosphoramide (HMPA) extends both the thermal stability threshold of sodium hexafluorophosphate (NaPF6) in dimethoxyethane (DME) electrolyte and the cycle life of double-layer capacitors. HMPA forms a stable complex with PF5, an intermediate in PF6 anion thermal degradation. Unbound, this intermediate leads to autocatalytic degradation of the electrolyte solution. The results of electrochemical impedance spectroscopy (EIS) and galvanostatic cycling measurements show large changes in the cell without the presence of HMPA at higher temperatures (≥60 °C). Fourier transform infrared spectroscopy (FTIR) on the liquid and gas phase of the electrolyte shows without HMPA the formation of measurable amounts of PF5 and HF. The complimentary results of these measurements proved the usefulness of using Lewis bases such as HMPA to inhibit the degradation of the electrolyte solution at elevated temperatures and potentially lead to improve cycle life of a nonaqueous capacitor. The results showed a large increase in capacitance retention during cycling (72% retention after 750,000 cycles). The results also provide evidence of major decomposition processes (0% capacitance retention after 100,000 cycles) that take place at higher temperatures without the additive of a thermal stability additive such as HMPA.

scholarly journals Investigation of the Formation and Decomposition Processes of the Sredneviluisky GCF Natural Gas Hydrates in Dispersed Media

2021 ◽  
Vol 1079 (4) ◽  
pp. 042028
Author(s):  
L P Kalacheva ◽  
I K Ivanova ◽  
A S Portnyagin ◽  
S A Solovieva ◽  
D R Egorov ◽  
...  
Keyword(s):  
Natural Gas ◽  
Gas Hydrates ◽  
Natural Gas Hydrates ◽  
Decomposition Processes ◽  
Dispersed Media

scholarly journals THE STEREOCHEMISTRY OF THE BACTERIAL DECOMPOSITION OF ALBUMIN

1917 ◽  
Vol 32 (3) ◽  
pp. 533-538
Author(s):  
Takaoki Sasaki ◽  
Ichiro Otsuka
Keyword(s):  
Bacterial Decomposition

scholarly journals Carbons Formed in Methane Thermal and Thermocatalytic Decomposition Processes: Properties and Applications

2021 ◽  
Vol 7 (3) ◽  
pp. 50
Author(s):  
Emmi Välimäki ◽  
Lasse Yli-Varo ◽  
Henrik Romar ◽  
Ulla Lassi
Keyword(s):  
Thermal Decomposition ◽  
Hydrogen Production ◽  
Energy Systems ◽  
Hydrogen Gas ◽  
Solid Carbon ◽  
Hydrogen Economy ◽  
Decomposition Processes ◽  
Different Types ◽  
Decomposition Of Methane ◽  
Thermocatalytic Decomposition

The hydrogen economy will play a key role in future energy systems. Several thermal and catalytic methods for hydrogen production have been presented. In this review, methane thermocatalytic and thermal decomposition into hydrogen gas and solid carbon are considered. These processes, known as the thermal decomposition of methane (TDM) and thermocatalytic decomposition (TCD) of methane, respectively, appear to have the greatest potential for hydrogen production. In particular, the focus is on the different types and properties of carbons formed during the decomposition processes. The applications for carbons are also investigated.

scholarly journals Effect of Biofertilizers Application on Soil Biodiversity and Litter Degradation in a Commercial Apricot Orchard

Agronomy ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1116
Author(s):  
Elena Baldi ◽  
Paola Gioacchini ◽  
Daniela Montecchio ◽  
Stefano Mocali ◽  
Livio Antonielli ◽  
...  
Keyword(s):  
Nir Spectroscopy ◽  
Microbial Composition ◽  
Trichoderma Spp ◽  
Soil Biodiversity ◽  
Decomposition Processes ◽  
Dta Analysis ◽  
Litter Deposition ◽  
Litter Degradation ◽  
Bacteria And Fungi ◽  
One Year

The aim of the present experiment was to determine if the supply of biofertilizers could differently stimulate the native microbiota, thus determining different patterns of organic material decomposition processes. The microbial composition of soil and litter was investigated by next generation sequencing using a metabarcoding approach. The chemical structure of the decomposing litterbags was investigated through the TG-DTA analysis and NIR spectroscopy. The study was conducted in an apricot orchard in Italy, and two different type of biofertilizers (AMF and Trichoderma spp.) were compared to unfertilized control over one year. Bacteria and fungi in soil, 162 days from litter deposition, evidenced differentiated clusters for control and both biofertilizers; on the other hand, only fungal composition of litterbags was modified as a consequence of Trichoderma spp. supply; no effect was observed in the bacterial community of litterbags. NIR and TG-DTA analysis evidenced a significant change over time of the chemical composition of litterbags with a faster degradation as a consequence of Trichoderma spp. supply testified by a higher degradation coefficient (1.9) than control (1.6) and AMF (1.7). The supply of biofertilizers partially modified the bacteria community of soil, while Trichoderma spp. Influenced the fungal community of the litter. Moreover, Trichoderma spp. Evidenced a faster and higher degradation of litter than AMF-biofertilizers, laying the foundation for an efficient use in orchard.

Natural Vulcanization Accelerators in Hevea Latex

1948 ◽  
Vol 21 (4) ◽  
pp. 853-859
Author(s):  
R. F. A. Altman
Keyword(s):  
Amino Acids ◽  
Experimental Results ◽  
The Other ◽  
Active Nitrogen ◽  
Nitrogen Bases ◽  
Other Hand ◽  
Decomposition Processes ◽  
Volatile Products ◽  
Nitrogenous Substances ◽  
The One

Abstract As numerous investigators have shown, some of the nonrubber components of Hevea latex have a decided accelerating action on the process of vulcanization. A survey of the literature on this subject points to the validity of certain general facts. 1. Among the nonrubber components of latex which have been investigated, certain nitrogenous bases appear to be most important for accelerating the rate of vulcanization. 2. These nitrogen bases apparently occur partly naturally in fresh latex, and partly as the result of putrefaction, heating, and other decomposition processes. 3. The nitrogen bases naturally present in fresh latex at later stages have been identified by Altman to be trigonelline, stachhydrine, betonicine, choline, methylamine, trimethylamine, and ammonia. These bases are markedly active in vulcanization, as will be seen in the section on experimental results. 4. The nitrogenous substances formed by the decomposition processes have only partly been identified, on the one hand as tetra- and pentamethylene diamine and some amino acids, on the other hand as alkaloids, proline, diamino acids, etc. 5. It has been generally accepted that these nitrogenous substances are derived from the proteins of the latex. 6. Decomposition appears to be connected with the formation of a considerable amount of acids. 7. The production of volatile nitrogen bases as a rule accompanies the decomposition processes. These volatile products have not been identified. 8. The active nitrogen bases, either already formed or derived from complex nitrogenous substances, seem to be soluble in water but only slightly soluble in acetone.

Activation energies of thermal decomposition processes of MgBr2.6H2O

1989 ◽  
Vol 148 ◽  
pp. 197-203 ◽  
Author(s):  
Yoram Kirsh ◽  
Shlomo Shoval ◽  
Shmuel Yariv
Keyword(s):  
Thermal Decomposition ◽  
Activation Energies ◽  
Decomposition Processes
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