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1.
Math Biosci Eng ; 19(6): 6072-6087, 2022 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-35603391

RESUMO

In this paper, we study stationary patterns of bistable reaction-diffusion cellular automata, i.e., models with discrete time, space and state. We show the rich variability based on the interplay of the capacity and viability and the specific form of reaction functions. While stationary k-periodic patterns occur naturally in many situations in large (exponential) numbers, there exist extreme situations for which there are no heterogeneous patterns. Moreover, nonmonotone dependence of the number of stationary patterns on the diffusion parameter is shown to be natural in the fully discrete setting.


Assuntos
Autômato Celular , Modelos Biológicos , Difusão , Idioma
2.
Appl Biochem Biotechnol ; 174(4): 1299-1308, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-25104003

RESUMO

Waste paper belongs to a group of quantitatively the most produced waste types. Enzymatic hydrolysis is becoming a suitable way to treat this type of waste and at the same time, to produce a valuable liquid biofuel, because reducing sugars solutions that are formed during the process of saccharification can be a precursor for following or simultaneous fermentation. If it will be possible to make the enzymatic hydrolysis of the waste paper economically viable, it could serve as one of the new ways to lower the dependence of the transport sector on oil in the future. Only several studies comparing the enzymatic hydrolysis of different waste papers were performed in the past; they are summarized in this manuscript. In our experimental trials, suitable technological conditions for waste paper enzymatic hydrolysis using enzymes from Novozymes® biomass kit: enzymes NS50013 and NS50010 were investigated. The following enzymatic hydrolysis parameters in laboratory scale trials were verified on high cellulose content substrates-filter paper and cellulose pulp: type of buffer, pH, temperature, concentration of the substrate, loading of the enzyme and rate of stirring.


Assuntos
Celulases/química , Celulose/química , Papel , Eliminação de Resíduos/métodos , Hidrólise
3.
Bioresour Technol ; 152: 543-7, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24314601

RESUMO

Enzymatic hydrolysis of waste paper is becoming a perspective way to obtain raw material for production of liquid biofuels. Reducing sugars solutions that arise from the process of saccharification are a precursors for following or simultaneous fermentation to ethanol. Different types of waste paper were evaluated, in terms of composition and usability, in order to select the appropriate type of the waste paper for the enzymatic hydrolysis process. Novozymes® enzymes NS50013 and NS50010 were used in a laboratory scale trials. Technological conditions, which seem to be the most suitable for hydrolysis after testing on cellulose pulp and filter paper, were applied to hydrolysis of widely available waste papers - offset paper, cardboard, recycled paper in two qualities, matte MYsol offset paper and for comparison again on model materials. The highest yields were achieved for the cardboard, which was further tested using various pretreatment combinations in purpose of increasing the hydrolysis yields.


Assuntos
Biotecnologia/métodos , Lipase/metabolismo , Papel , Resíduos , Biocombustíveis , Soluções Tampão , Hidrólise , Solubilidade , Soluções
4.
Waste Manag ; 22(4): 443-51, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12099503

RESUMO

This paper describes possible ways of prediction of nitrogen oxides formation during combustion of hydrocarbon fuels. Mathematical model based on experimental data acquired from the testing facility has been developed. The model enables to predict--at a high probability measure--the extent of nitrogen oxides emissions. The mathematical model of nitrogen oxide formation relies on the application of simplified kinetic equations describing the formation of nitrogen oxides at so-called equivalent temperature. It is a semi-empirical model that comes out of experimental knowledge. An important role played by the burner design itself has been emphasized and therefore an important supplementary parameter of the model is the characteristic of the burner design. It has been established that there was a good agreement between experimental data and those calculated by the application of the model to various conditions marked out by different combustion parameters in the combustion chamber. The results obtained by application of the model respect the influence of parameters validated by industrial practice that control the formation of nitrogen oxides in the course of fuel combustion. Such parameters-first of all-tare the temperature in the combustion chamber and the concentration of the substances taking part in the reaction. By application of the model, it is possible to assess the consequence of, for example the surplus of combustion air, the increase of temperature of combustion air, the supply of inert gas, etc. on the nitrogen oxides emissions of the operating burner under evaluation. Efficient combining of experience and sophisticated approach together with importance of thus access for an improved design are shown.


Assuntos
Combustíveis Fósseis , Modelos Teóricos , Óxidos de Nitrogênio/análise , Poluentes Atmosféricos , Desenho de Equipamento , Previsões , Incineração
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