scholarly journals A New Approach to Assess the Effect of Various Humic Compounds on the Metabolic Activity of Cells Participating in Methanogenesis

2019 ◽  
Vol 11 (11) ◽  
pp. 3158 ◽  
Author(s):  
Nikolay Stepanov ◽  
Olga Senko ◽  
Irina Perminova ◽  
Elena Efremenko
Keyword(s):  
Metabolic Activity ◽  
Fulvic Acids ◽  
Energy Status ◽  
Potassium Humate ◽  
New Approach ◽  
Humic Compounds ◽  
Atp Concentration ◽  
The Media ◽  
Adequate Evaluation ◽  
Kinetics Of

The possible use of the concentration of intracellular adenosine triphosphate (ATP) as a parameter enabling quick and adequate evaluation of the metabolic activity of methanogenic cells was demonstrated in the work. This approach was used to analyze the effect of introducing potassium humate and fulvic acids (1–10 g/L) into media with four different methanogenic consortia producing biogas. The ATP concentration was analyzed by the bioluminescent luciferin–luciferase method at the beginning and end of the process. During the entire process, the biogas composition, biogas efficiency, and the kinetics of methanogenesis in the presence of humic compounds were determined. The increase in the concentration of potassium humate led to a decrease in the overall energy status of the cells and reduced methanogenesis efficiency. However, fulvic acids introduced into the media stimulated methanogenesis in half of the tested consortia, which was accompanied by an increase in ATP concentration in cell samples. So, a positive correlation between the metabolic activity of cells in biogas formation and the concentration of ATP was observed. ATP concentration control appears to be an attractive tool for finding compounds that suppress methanogenesis in landfills.

scholarly journals Suppression of Methane Generation during Methanogenesis by Chemically Modified Humic Compounds

Antioxidants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1140
Author(s):  
Elena Efremenko ◽  
Olga Senko ◽  
Nikolay Stepanov ◽  
Nikita Mareev ◽  
Alexander Volikov ◽  
...  
Keyword(s):  
Antioxidant Properties ◽  
Nutrient Media ◽  
Potassium Humate ◽  
Methane Generation ◽  
Chemically Modified ◽  
Humic Compounds ◽  
Negative Effect ◽  
The Media ◽  
First Time ◽  
Derivatives Of

The introduction of various concentrations of chemically modified humic compounds (HC) with different redox characteristics into the media with free and immobilized anaerobic consortia accumulating landfill gases was studied as approach to their functioning management. For this purpose, quinone (hydroquinone, naphthoquinone or methylhydroquinone) derivatives of HC were synthesized, which made it possible to vary the redox and antioxidant properties of HC as terminal electron acceptors in methanogenic systems. The highest acceptor properties were obtained with potassium humate modified by naphthoquinone. To control possible negative effect of HC on the cells of natural methanogenic consortia, different bioluminescent analytical methods were used. The addition of HC derivatives, enriched with quinonones, to nutrient media at concentrations above 1 g/L decreased the energetic status of cells and the efficiency of the methanogenesis. For the first time, the significant decrease in accumulation of biogas was reached as effect of synthetic HC derivatives, whereas both notable change of biogas composition towards increase in the CO2 content and decrease in CH4 were revealed. Thus, modification with quinones makes it possible to obtain low-potential HC derivatives with strongly pronounced acceptor properties, promising for inhibition of biogas synthesis by methanogenic communities.

Influence of medium on alkaline hydrolysis of succinic acid monomethyl and monopropyl esters

1980 ◽  
Vol 45 (11) ◽  
pp. 2873-2882
Author(s):  
Vladislav Holba ◽  
Ján Benko
Keyword(s):  
Succinic Acid ◽  
Kinetic Parameters ◽  
Alkaline Hydrolysis ◽  
Specific Interactions ◽  
Nonaqueous Media ◽  
The Media ◽  
Kinetics Of ◽  
Hydrolysis Of

The kinetics of alkaline hydrolysis of succinic acid monomethyl and monopropyl esters were studied in mixed aqueous-nonaqueous media at various temperatures and ionic strengths. The results of measurements are discussed in terms of electrostatic and specific interactions between the reactants and other components of the reaction mixture. The kinetic parameters in the media under study are related to the influence of the cosolvent on the solvation sphere of the reactants.

scholarly journals Comparison of Conventional and Flash Spark Plasma Sintering of Cu–Cr Pseudo-Alloys: Kinetics, Structure, Properties

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 141
Author(s):  
Kirill V. Kuskov ◽  
Mohammad Abedi ◽  
Dmitry O. Moskovskikh ◽  
Illia Serhiienko ◽  
Alexander S. Mukasyan
Keyword(s):  
Heating Rate ◽  
Spark Plasma Sintering ◽  
Electric Circuits ◽  
Nanostructured Particles ◽  
Plasma Sintering ◽  
Spark Plasma ◽  
The Media ◽  
Copper Chromium ◽  
Kinetics Of ◽  
Structure Properties

Spark plasma sintering (SPS) is widely used for the consolidation of different materials. Copper-based pseudo alloys have found a variety of applications including as electrodes in vacuum interrupters of high-voltage electric circuits. How does the kinetics of SPS consolidation for such alloys depend on the heating rate? Do SPS kinetics depend on the microstructure of the media to be sintered? These questions were addressed by the investigation of SPS kinetics in the heating rate range of 0.1 to 50 K/s. The latter conditions were achieved through flash spark plasma sintering (FSPS). We also compared the sintering kinetics for the conventional copper–chromium mixture and for the mechanically induced copper/chromium nanostructured particles. It was shown that, under FSPS conditions, the observed maximum consolidation rates were 20–30 times higher than that for conventional SPS with a heating rate of 100 K/min. Under the investigated conditions, the sintering rate for mechanically induced composite Cu/Cr particles was 2–4 times higher compared to the conventional Cu + Cr mixtures. The apparent sintering activation energy for the Cu/Cr powder was twice less than that for Cu–Cr mixture. It was concluded that the FSPS of nanostructured powders is an efficient approach for the fabrication of pseudo-alloys.

scholarly journals Simulation of Folding Kinetics for Aligned RNAs

Genes ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 347
Author(s):  
Jiabin Huang ◽  
Björn Voß
Keyword(s):  
Evolutionary Conservation ◽  
Folding Kinetics ◽  
New Approach ◽  
Computational Approaches ◽  
Reasonable Time ◽  
Valuable Method ◽  
Kinetics Of ◽  
Insight Into ◽  
Folding Space ◽  
Standing Problem

Studying the folding kinetics of an RNA can provide insight into its function and is thus a valuable method for RNA analyses. Computational approaches to the simulation of folding kinetics suffer from the exponentially large folding space that needs to be evaluated. Here, we present a new approach that combines structure abstraction with evolutionary conservation to restrict the analysis to common parts of folding spaces of related RNAs. The resulting algorithm can recapitulate the folding kinetics known for single RNAs and is able to analyse even long RNAs in reasonable time. Our program RNAliHiKinetics is the first algorithm for the simulation of consensus folding kinetics and addresses a long-standing problem in a new and unique way.

Studies on the structure and function of the mammalian testis V. Steroid metabolism by isolated interstitium and seminiferous tubules of the human testis

1974 ◽  
Vol 186 (1083) ◽  
pp. 99-120 ◽  
Keyword(s):  
Metabolic Activity ◽  
General Pattern ◽  
Steroid Metabolism ◽  
Human Testis ◽  
Clinical Aspects ◽  
Seminiferous Tubules ◽  
Bicarbonate Buffer ◽  
The Media ◽  
The Individual ◽  
And Function

Tissue was obtained from the testes of three men, two in the age range 72-75 years (subjects A and B) and one aged 25 years (subject C). Parts of the testes were dissected to obtain samples of interstitium and tubules. The individual components and whole tissue were each incubated with equimolar concentrations of [7 α - 3 H]pregnenolone and [4- 14 C]progesterone in Krebs-Ringer bicarbonate buffer pH 7.4, at 35 °C with the addition of glucose but without cofactors. Some incubations were carried out with the substrates [4- 14 C]androstenedione and [7 α - 3 H]testosterone. The media were extracted both at various time intervals throughout the incubation for a kinetic study of the metabolic activity and after a fixed interval of time at the end of the incubations. In some incubations with whole tissue both media and tissue were extracted. Both the tubules and interstitium displayed steroid metabolic activity. Qualitatively they yielded the same range of metabolites, one series leading to the formation of testosterone (∆ 5 pathway) and the other to a variety of C 21 compounds as represented by 5 α -pregnan-3 β -ol-20-one. With similar amounts of tissue there was little difference in the yields of the main products formed by the tubules as compared with those formed by the interstitium; in incubations with [4- 14 C]androstenedione the rate of conversion to [ 14 C ]testosterone by the tubules greatly exceeded that due to the interstitium. Marked differences were found in the pattern of steroid metabolism by whole tissue as compared to the general pattern presented by the corresponding tubules and interstitium. It is concluded that the seminiferous tubules and interstitium of the human testis are both capable of steroid metabolism and hence that whole tissue incubations alone are of limited value and could give rise to misleading data. Some clinical aspects of the results are briefly discussed.

Water decolorization using UV radiation and hydrogen peroxide: A kinetic study

2001 ◽  
Vol 44 (5) ◽  
pp. 53-60 ◽  
Author(s):  
C.A. Martín ◽  
O.M. Alfano ◽  
A.E. Cassano
Keyword(s):  
Hydrogen Peroxide ◽  
Uv Radiation ◽  
Absorption Rate ◽  
Fulvic Acids ◽  
Photon Absorption ◽  
Contaminant Concentration ◽  
Organic Substances ◽  
Mechanistic Approach ◽  
Natural Contamination ◽  
Kinetics Of

Sometimes, provision of water for domiciliary consumption faces the problem of natural contamination originated by the presence of organic substances such as humic or fulvic acids. Very often, after conventional sanitary treatments this water exhibits a persistent yellowish coloration that affects its use. Moreover, these substances may act as precursors of tri-halomethanes formation during pre-desinfection with chlorine. This paper presents, with a simplified mechanistic approach, the intrinsic reaction kinetics of natural water decolorization employing UV radiation and hydrogen peroxide. The main variables for the model are: contaminant concentration expressed as TOC, hydrogen peroxide concentration and the photon absorption rate.

Performing the ‘lifeworld’ in public education campaigns

2010 ◽  
Vol 1 (2) ◽  
pp. 284-310 ◽  
Author(s):  
Michelle M. Lazar
Keyword(s):  
Public Education ◽  
Rap Music ◽  
Dual Processes ◽  
Public Performance ◽  
New Approach ◽  
The Public ◽  
Local Television ◽  
The Media ◽  
Education Campaigns ◽  
Real Person

In Singapore, top down public education campaigns have long been a mode of governance by which the conduct of citizens is constantly regulated. This article examines how in two fairly recent campaigns, a new approach to campaign communication is used that involves media interdiscursivity, viz., the mixing of discourses and genres in which the media constitute a significant element. The present approach involves the appropriation of a popular local television character, ‘Phua Chu Kang’, in order to address the public through educational rap music videos. Media interdiscursivity is based on an attempt to engage the public via a discourse of the ‘lifeworld’. The present article analyzes the ‘lifeworld’ discourse in terms of a combination of two processes, ‘informalization’ (the use of informal and conversational modes of address) and ‘communitization’ (the semiotic construction of a community of people). The dual processes are examined and discussed in relation to the choice of Phua Chu Kang as an ‘ordinary’ and almost ‘real’ person, including his informal register and speech style; his use of Singlish; and his construction of ‘community.’ The presence of Singlish, in particular, is interesting because (despite the official disdain for the language) it is included as part of PCK’s public performance of the lifeworld. The article concludes by considering this form of media interdiscursivity as the government’s shrewd way of achieving its social governance goals.

New Fields in Classifying Algorithms for Content Awareness

2012 ◽  
Vol 7 (2) ◽  
pp. 1-15
Author(s):  
Radu-Dinel Miruta ◽  
Cosmin Stanuica ◽  
Eugen Borcoci
Keyword(s):  
Packet Classification ◽  
Tuple Space ◽  
New Approach ◽  
Data Packets ◽  
Server Side ◽  
The Media ◽  
Bit Vector ◽  
Edge Router ◽  
Content Aware

The content aware (CA) packet classification and processing at network level is a new approach leading to significant increase of delivery quality of the multimedia traffic in Internet. This paper presents a solution for a new multi-dimensional packet classifier of an edge router, based on content - related new fields embedded in the data packets. The technique is applicable to content aware networks. The classification algorithm is using three new packet fields named Virtual Content Aware Network (VCAN), Service Type (STYPE), and U (unicast/multicast) which are part of the Content Awareness Transport Information (CATI) header. A CATI header is inserted into the transmitted data packets at the Service/Content Provider server side, in accordance with the media service definition, and enables the content awareness features at a new overlay Content Aware Network layer. The functionality of the CATI header within the classification process is then analyzed. Two possibilities are considered: the adaptation of the Lucent Bit vector algorithm and, respectively, of the tuple space search, in order to respond to the suggested multi-fields classifier. The results are very promising and they prove that theoretical model of inserting new packet fields for content aware classification can be implemented and can work in a real time classifier.

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