scholarly journals Optimization of Gas-Water Absorption Equilibrium of Carbon Dioxide for Algae Liquors: Selection of Alkaline Buffering Chemicals

2016 ◽  
Vol 2016 ◽  
pp. 1-5
Author(s):  
Wen-Hsi Cheng ◽  
Ming-Shean Chou
Keyword(s):  
Carbon Dioxide ◽  
Sodium Carbonate ◽  
Egeria Densa ◽  
Optimal Conditions ◽  
Liquid Equilibrium ◽  
Ph Values ◽  
Carbonate Concentration ◽  
Different Temperatures ◽  
The Mean ◽  
Selection Of

The apparent Henry’s Law constant (H′), which quantifies the concentration partition of a gas-liquid equilibrium of carbon dioxide (CO2), is used to optimize the absorption of carbon dioxide in algae liquors. The values ofH′were examined under various conditions: in water at different temperatures (27 and 37°C), in alkaline buffering chemicals (sodium hydroxide (NaOH) and sodium carbonate (Na2CO3)), and in aquatic algae plants (Egeria densaandAnubias barteri nana). The optimal conditions for CO2absorption can be obtained by controlling the aqueous pH values (around weak alkalinity with pH 9-10) using sodium carbonate as an alkaline buffering chemical at 27°C, yielding exactH′values of around 16.3–21.3 atm/M, which were obtained from the mean gaseous CO2concentration of 803 ppm and the total aqueous carbonate concentration of 4.085 mg/L. The experimental results reveal that an alkaline buffering compound, sodium carbonate, can be added to water to maintain a constant aqueous alkalinity enough for the fixation of carbon dioxide by the photosynthesis of green algae in a photobioreactor.

scholarly journals High Pressure Vapour-Liquid Equilibrium of Volatiles in Supercritical Carbon Dioxide

2013 ◽  
Vol 34 (3) ◽  
pp. 387-392 ◽  
Author(s):  
Karina Gurgenova ◽  
Rafał Bogeł-Łukasik ◽  
Paweł Wawrzyniak
Keyword(s):  
Experimental Data ◽  
Carbon Dioxide ◽  
High Pressure ◽  
Equation Of State ◽  
Supercritical Carbon Dioxide ◽  
Process Parameters ◽  
Liquid Equilibrium ◽  
Isothermal Conditions ◽  
Selection Of ◽  
Supercritical Carbon

Abstract Binary vapour-liquid equilibrium of thymoquinone and carbon dioxide at the isothermal conditions was carried out at temperature 323.15 K and pressures from 6 to 10 MPa. The experimental data were fitted to the Soave-Redlich-Kwong equation of state. Results could be used for selection of process parameters in separation of volatiles from raw oil or for evaluation of existing separation technologies.

scholarly journals Acidophilic chemolithotrophic microorganisms: prospects for use in biohydrometallurgy and microbial fuel cells

2021 ◽  
Vol 11 (1) ◽  
pp. 34-52
Author(s):  
O. B. Kalashnikova ◽  
A. V. Kashevskii ◽  
N. S. Vardanyan ◽  
D. Erdenechimeg ◽  
G. O. Zhdanova ◽  
...  
Keyword(s):  
Fuel Cells ◽  
Microbial Fuel Cells ◽  
Low Ph ◽  
Biofuel Cells ◽  
Mining Wastes ◽  
Optimal Conditions ◽  
Bioelectrochemical System ◽  
Ph Values ◽  
Sulphide Ores ◽  
Selection Of

Acidophilic chemolithotrophic microorganisms are used in biohydrometallurgy for the extraction of metals from sulphide ores. Some types of microorganisms belonging to this group are capable of generating electricity under certain conditions. This circumstance determined a recent upsurge of research interest in their use in biofuel cells. Under a constant supply of the substrate to the bioelectrochemical system, acidophilic chemolithotrophic microorganisms are capable of producing electricity for a prolonged period of time. The use of extremophiles in microbial fuel cells is of particular interest, since these microorganisms can serve as bioelectrocatalysts at extreme pH, salinity and temperature, while the vast majority of microorganisms are unable to survive under these conditions. Therefore, selection of optimal conditions and approaches to controlling the work of acidophilic chemolithotrophic microorganisms in such fuel cells is of particular importance. On this basis, a technology for the simulteneous bioleaching of metals from poor ores and the generation of electricity can be developed. Biofuel cells operating at low pH values using acidophilic chemolithotrophic microorganisms are yet to be investigated. The number of studies on acidophilic electroactive microorganisms is very limited. In this regard, the purpose of this review was to consider the prospects for the use of acidophilic chemolithotrophic microorganisms as bioagents in microbial fuel cells. The reviewed publications demonstrate that chemolithotrophic microorganisms can act as both anodic (metal-reducing, sulphur-oxidizing microorganisms) and cathodic (metal-oxidizing prokaryotes, sulfate reducers) highly efficient bioagents capable of using mining wastes as substrates.

Liquid–Liquid Equilibrium of Two-Phase Aqueous Systems Composed of PEG 400, Na2SO4, and Water at Different Temperatures and pH Values: Correlation and Thermodynamic Modeling

2018 ◽  
Vol 63 (5) ◽  
pp. 1352-1362 ◽  
Author(s):  
Rui Gomes Nascimento ◽  
Rafael da Costa Ilhéu Fontan ◽  
Renata Cristina Ferreira Bonomo ◽  
Cristiane Martins Veloso ◽  
Sérgio de Sousa Castro ◽  
...  
Keyword(s):  
Thermodynamic Modeling ◽  
Aqueous Systems ◽  
Liquid Equilibrium ◽  
Two Phase ◽  
Ph Values ◽  
Peg 400 ◽  
Different Temperatures

Der Sommer und Herbst 2003 aus phänologischer Sicht | Summer and autumn 2003 from a phenological point of view

2004 ◽  
Vol 155 (5) ◽  
pp. 142-145 ◽  
Author(s):  
Claudio Defila
Keyword(s):  
Time Series ◽  
New Record ◽  
Point Of View ◽  
Late Spring ◽  
Mean Deviation ◽  
Leaf Shedding ◽  
The Mean ◽  
Very High ◽  
Selection Of

The record-breaking heatwave of 2003 also had an impact on the vegetation in Switzerland. To examine its influences seven phenological late spring and summer phases were evaluated together with six phases in the autumn from a selection of stations. 30% of the 122 chosen phenological time series in late spring and summer phases set a new record (earliest arrival). The proportion of very early arrivals is very high and the mean deviation from the norm is between 10 and 20 days. The situation was less extreme in autumn, where 20% of the 103 time series chosen set a new record. The majority of the phenological arrivals were found in the class «normal» but the class«very early» is still well represented. The mean precocity lies between five and twenty days. As far as the leaf shedding of the beech is concerned, there was even a slight delay of around six days. The evaluation serves to show that the heatwave of 2003 strongly influenced the phenological events of summer and spring.

Computational simulation applied to improve fuel bioethanol distillation

2013 ◽  
pp. 645-650
Author(s):  
Fabio R.M. Batista ◽  
Antonio J.A. Meirelles
Keyword(s):  
Experimental Validation ◽  
Computational Simulation ◽  
Industrial Plant ◽  
Careful Study ◽  
Optimal Conditions ◽  
Liquid Equilibrium ◽  
Steam Consumption ◽  
Wine Composition ◽  
Standard Solution ◽  
Central Composite

Experimental validation of the process simulation a typical industrial bioethanol unit was conducted, comparing the obtained results with the information collected in an industrial plant. A standard solution containing water, ethanol and 17 congeners was chosen to represent the fermented must, whose composition was selected according to analyses of samples of industrial wines. A careful study of the vapour-liquid equilibrium of the wine components was performed. An attempt to optimise the industrial plant was conducted considering two optimising approaches: the central composite design (CCD) and the Sequential Quadratic Programming (SQP). The process was investigated in terms of bioethanol alcoholic graduation, ethanol recovery, energy consumption and ethanol loss. The results showed that the simulation approach was capable of correctly reproducing a real plant of bioethanol distillation and that the optimal conditions are slightly different from those used at the industrial plant investigated. Substantial fluctuations in wine composition were easily controlled for the two loop controls preventing an off-specification product. The optimised conditions indicate a distillation process able to produce bioethanol according to the legislation requirements and with appropriate steam consumption and loss of ethanol. However, for the production of alcohols with superior qualities, substantial changes in the production system may be required.

Caracterização da Peneira Média em Clones de Coffea canephora

REVISTA FIMCA ◽  
2018 ◽  
Vol 5 (2) ◽  
pp. 28-31
Author(s):  
Darlan Darlan Sanches Barbosa Alves ◽  
Victor Mouzinho Spinelli ◽  
Marcos Santana Moraes ◽  
Carolina Augusto De Souza ◽  
Rodrigo da Silva Ribeiro ◽  
...  
Keyword(s):  
Genetic Improvement ◽  
Block Design ◽  
Coffea Canephora ◽  
Coffee Production ◽  
Randomized Block Design ◽  
Significant Difference ◽  
The Mean ◽  
Four Blocks ◽  
Selection Of

Introdução: O estado de Rondônia se destaca como tradicional produtor de café, sendo o segundo maior produtor brasileiro de C. canephora. No melhoramento genético de C. canephora, a seleção de plantas de elevada peneira média está associada à bebida de qualidade superior. Objetivos: O objetivo desse estudo foi avaliar a variabilidade genética de clones de C. canephora para o tamanho dos grãos, mensurado a partir da avaliação da peneira média (PM). Materiais e Métodos: Para isso, foi conduzido ao longo de dois anos agrícolas experimento no campo experimental da Embrapa no município de Ouro Preto do Oeste-RO, para a avaliação da peneira média de 130 genótipos (clones) com características das variedades botânicas Conilon, Robusta e híbridos intervarietais. O delineamento experimental utilizado foi de blocos ao acaso, com quatro repetições de quatro plantas por parcela. Resultados: Não houve resultados significativos para a interação clones X anos, indicando uma maior consistência no comportamento das plantas ao longo do tempo. Porém foram observadas diferenças significativas para o tamanho dos grãos entre os genótipos avaliados, possibilitando selecionar genótipos superiores. Conclusão: Os genótipos agruparam-se em cinco classes de acordo com o teste de média, subsidiando a caracterização de um gradiente de variabilidade da característica avaliada ABSTRACTIntroduction: Coffea canephora accounts for approximately 35% of the world's coffee production. The state of Rondônia stands out as a traditional coffee producer, being the second largest Brazilian producer of C. canephora. In the classical genetic improvement of C. anephora, the selection of plants of high average sieve is associated with a drink of superior quality. Objectives: The objective of this udy was to evaluate the genetic variability of Coffea canephora clones for the agronomic medium sieve (PM). Materials and Methods: The experiment was conducted in the experimental field of Embrapa, municipality of OuroPreto do Oeste-RO, located at coordinates 10º44'53 "S and 62º12'57". One hundred thirty genotypes (clones) of botanical characteristics Conilon, Robusta and intervarietal hybrids were evaluated in the agricultural years 2013-2014 and 2014-2015. The experimental design was a randomized block design with four blocks and four plants per plot, spacing 3.5 x 1.5 meters between plants. Results: Significant difference was found for the grain size. According to the F test, at 5% probability, the genotypes were grouped into five classes according to the mean test. Conclusion: The results obtained subsidized the characterization of a variability gradient of the evaluated trait.

Excess entropy of the systems of molecules differing in size and shape

1983 ◽  
Vol 48 (1) ◽  
pp. 192-198 ◽  
Author(s):  
Tomáš Boublík
Keyword(s):  
Equation Of State ◽  
Hard Spheres ◽  
Excess Entropy ◽  
Convex Bodies ◽  
Pure Substance ◽  
Liquid Equilibrium ◽  
Simple Rules ◽  
Different Shapes ◽  
The Mean

The excess entropy of mixing of mixtures of hard spheres and spherocylinders is determined from an equation of state of hard convex bodies. The obtained dependence of excess entropy on composition was used to find the accuracy of determining ΔSE from relations employed for the correlation and prediction of vapour-liquid equilibrium. Simple rules were proposed for establishing the mean parameter of nonsphericity for mixtures of hard bodies of different shapes allowing to describe the P-V-T behaviour of solutions in terms of the equation of state fo pure substance. The determination of ΔSE by means of these rules is discussed.

scholarly journals Comparative Analysis of Different Local Anesthetic Solutions Available in Market: An In Vitro and Clinical Study

2021 ◽  
Author(s):  
Eisha Imran ◽  
Faisal Moeen ◽  
Beenish Abbas ◽  
Bakhtawar Yaqoob ◽  
Mehreen Wajahat ◽  
...  
Keyword(s):  
Comparative Analysis ◽  
Local Anesthetic ◽  
Compositional Analysis ◽  
Bacterial Activity ◽  
Similar Composition ◽  
Ph Values ◽  
Significant Difference ◽  
The Mean ◽  
The Difference

Abstract Objectives The study aimed to evaluate and compare various commercially available local anesthetic solutions. Materials and Methods A total of 150 commercially available local anesthetic cartridges of similar composition (2% lidocaine with epinephrine 1:100,000) were randomly collected and divided into 3 groups. The designations of groups were selected from their product names such that each group consisted of 60 cartridges. Group S (Septodont, France) Group M (Medicaine, Korea) and Group H (HD-Caine, Pakistan). The samples were divided into five sub-groups, each consisting of 10 cartridges from each group to investigate each parameter. Results The acquired data was statistically analyzed and compared (using SPSS version 12). Compositional analysis revealed a non-significant (P>0.05) difference when the three Groups were compared with standard lidocaine and epinephrine solutions. The mean pH values of samples from group S, M and H respectively fell within the range of pH values of commercially available solutions. Non-significant difference in EPT values of Group S and H was found when efficacy was compared (p = 0.3), however a significant difference (p < 0.01) was observed in contrast to Group M. Anti-bacterial activity was observed in all the group and a non-significant difference in cell viability values of Group S and M was found (p = 0.6), while the difference was significant in comparison to Group H. Conclusion Within the limitations of these investigations, it appears that the properties of different manufacturers fall within the recommended ranges as mentioned in literature and do not appear to be statistically different in the variables we have tested.

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