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1.
Poult Sci ; 99(8): R4101, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33044919

RESUMO

This article has been retracted: please see Elsevier Policy on Article Withdrawal (http://www.elsevier.com/locate/withdrawalpolicy). The authors retract the above paper due to: 1) conflict of interest among the authors; and 2) addition of coauthor Dr. Muhammad Younus without his knowledge or permission. The authors apologize for these two grave mistakes.

2.
Bioresour Technol ; 262: 333-337, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29754765

RESUMO

The aim of this study was to investigate the impact of mixing intensity and mixing flow patterns on solid waste degradation, and production of valuable intermediate by-products such as acetic acid. Total suspended solids generally decreased, soluble chemical oxygen demand, dissolved organic carbon, and acetic acid concentration generally increased with the progress of the reaction and increase in the mixing intensity. The results showed that axial-radial flow pattern (using pitch blade impeller) and medium impeller speed (500 rpm) resulted in a higher degree of solid degradation and production of acetic acid.


Assuntos
Ácido Acético/química , Reatores Biológicos , Carbono/química , Análise da Demanda Biológica de Oxigênio , Hidrodinâmica , Oxirredução , Eliminação de Resíduos Líquidos
3.
ISA Trans ; 76: 167-177, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29563020

RESUMO

Industrial methanol production involves a multi component feed containing methanol, water and trace levels of ethanol being refined to produce AA grade methanol at high product recovery. Due to practical constraints, the bottoms discharge of the column is primarily water with only trace of methanol impurities. As a result of these constraints, ethanol, which is a non-key middle boiling component gets "trapped" near the side draw of the column forming an ethanol bulge, which in turn results in non-linear, inverse, time and state varying behaviour of the side draw ethanol composition. In this work, we established that the existence of the ethanol bulge creates the complex process behaviour of the side draw ethanol composition and that this bulge needs to be explicitly controlled. This type of explicit composition bulge analysis and subsequent control has not been attempted on methanol distillation columns before. For this purpose a novel, robust and practical side draw control scheme to detect and remedy the excess ethanol bulge movement using override control is presented. The side draw controller, together with other regulatory controllers is shown to maintain on-specification operations of the column. Disturbance rejection tests carried out illustrate that the side draw control scheme will keep the column operating within commercial specification. It is also shown that a traditional DV control structure is unable to achieve this objective.

4.
Waste Manag ; 71: 494-501, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29017873

RESUMO

Food waste is gaining increasing attention worldwide due to growing concerns over its environmental and economic costs. Understanding the rheological behaviour of food waste is critical for effective processing so rheological measurements were carried out for different food waste compositions at 25, 35 and 45 °C. Food waste samples of various origins (carbohydrates, vegetables & fruits, and meat), anaerobically digested and diluted samples were used in this study. The results showed that food waste exhibits shear-thinning flow behaviour and viscosity of food waste is a function of temperature and composition. The composition of food waste affected the flow properties. Viscosity decreased at a given temperature as the proportion of carbohydrate increased. This may be due to the high water content of vegetable & fruits as the total solids fraction is likely to be a key controlling factor of the rheology. The Herschel-Bulkley model was used successfully to model food waste flow behaviour. Also, a higher strain was needed to break down the structure of the food waste as digestion time increased.


Assuntos
Alimentos , Reologia , Resíduos Sólidos , Esgotos , Temperatura , Viscosidade
5.
Bioresour Technol ; 245(Pt A): 234-241, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28892696

RESUMO

Sewage sludge is a significant by-product from wastewater treatment plants but is potentially hazardous due to its pathogenic or harmful contents, such as toxic metals. Subcritical water wet oxidation (SCWO) is one method of hydrothermal processing which has recently been used in research and industry for treating sludge. This study investigated the effect of SCWO on metals such as Al, Cu, Fe, and Zn in sludge, including the content of metals in the liquid or solid phase after SCWO and their stability distributions according to Tessier's method. During SCWO, most metals were significantly accumulated and stabilised in the solid phase with very limited leaching. The temperature was found to be the most significant factor for metals immobilisation, followed by reaction time, while pH had negligible effect. The optimal conditions of SCWO on metals were found at 240°C, 60min, pH 5 in this study.


Assuntos
Metais , Esgotos , Metais Pesados , Oxirredução , Temperatura , Água
6.
Bioresour Technol ; 239: 171-179, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28521226

RESUMO

New technologies are needed to recover phosphate from organic wastes, such as sewage sludge. Sewage sludge can be hydrothermally treated to make it safe but this process is expensive. Recovering a valuable by-product, such as phosphate, could improve the economics of hydrothermal treatment. Therefore, the technical and preliminary differential cost analysis of combining hydrothermal treatment with phosphate recovery (by precipitation of magnesium ammonium phosphate (struvite)) was investigated. The effects of pH, magnesium ion dose, and either wet oxidation or thermal hydrolysis hydrothermal treatment were examined. Phosphate recovery was more sensitive to pH than magnesium ion concentration, with diminishing rates of recovery at high levels of both. Also, more struvite was recovered following wet oxidation treatment than thermal hydrolysis. Preliminary differential cost analysis showed that wet oxidation combined with precipitation at an optimal pH and magnesium ion dose could generate revenue.


Assuntos
Esgotos , Estruvita , Eliminação de Resíduos Líquidos , Precipitação Química , Hidrólise , Compostos de Magnésio , Fosfatos , Fósforo
7.
Br Poult Sci ; 57(4): 451-61, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27057651

RESUMO

The study was designed to investigate the replication of a re-assortant H9N2 avian influenza virus (AIV) and induction of the interferon (IFNγ) response after aerosol or intranasal inoculation with the virus in guinea fowl. To determine virus shedding pattern, oropharyngeal and cloacal swabs and tissue specimens of trachea, lungs, spleen and caecal tonsils were collected post-inoculation (pi). Infected guinea fowl showed mild clinical signs, while negative control guinea fowl remained healthy and active throughout the experiment irrespective of the inoculation route. However, the clinical signs were more prominent in guinea fowl infected through the aerosol route. Virus was detected in all oropharyngeal and cloacal swabs up to 7 d pi in guinea fowl from both inoculation groups. However, virus was detected more frequently and in higher titres in oropharyngeal swabs and specimens of trachea and lungs from the group exposed to aerosols than in the group given intranasal drops. In accordance with viral replication findings, expression of IFNγ was up-regulated on 1, 2 and 4 d pi to a significantly higher level in lung tissue specimens from the group exposed to virus aerosol than from controls treated with PBS intranasally. On the other hand, IFNγ was up-regulated above that of controls in lung tissue specimens from the group treated with intranasal drops of virus only on 4 d pi. These findings indicate that virus administered in aerosols was more efficient in infecting the lower respiratory tract and in inducing activity of the IFNγ gene than virus administered as intranasal drops. The results of this study suggest that virus aerosols cause more intense respiratory infection and increase the shedding of the H9N2 AIV in guinea fowl, highlighting the potential role of guinea fowl as a mixing bowl for transmission and maintenance of H9N2 AIV between poultry premises.


Assuntos
Galinhas , Galliformes , Regulação da Expressão Gênica , Vírus da Influenza A Subtipo H9N2/fisiologia , Influenza Aviária/genética , Doenças das Aves Domésticas/genética , Replicação Viral , Administração Intranasal/veterinária , Aerossóis/administração & dosagem , Animais , Proteínas Aviárias/genética , Proteínas Aviárias/metabolismo , Ceco/virologia , Regulação da Expressão Gênica/imunologia , Influenza Aviária/metabolismo , Influenza Aviária/virologia , Interferons/genética , Interferons/metabolismo , Doenças das Aves Domésticas/metabolismo , Doenças das Aves Domésticas/virologia , Sistema Respiratório/virologia , Baço/virologia
8.
J Dairy Sci ; 99(5): 3380-3395, 2016 May.
Artigo em Inglês | MEDLINE | ID: mdl-26971156

RESUMO

The modeling of dairy processing using a generic process simulator suffers from shortcomings, given that many simulators do not contain milk components in their component libraries. Recently, pseudo-milk components for a commercial process simulator were proposed for simulation and the current work extends this pseudo-milk concept by studying the effect of both total milk solids and temperature on key physical properties such as thermal conductivity, density, viscosity, and heat capacity. This paper also uses expanded fluid and power law models to predict milk viscosity over the temperature range from 4 to 75°C and develops a succinct regressed model for heat capacity as a function of temperature and fat composition. The pseudo-milk was validated by comparing the simulated and actual values of the physical properties of milk. The milk thermal conductivity, density, viscosity, and heat capacity showed differences of less than 2, 4, 3, and 1.5%, respectively, between the simulated results and actual values. This work extends the capabilities of the previously proposed pseudo-milk and of a process simulator to model dairy processes, processing different types of milk (e.g., whole milk, skim milk, and concentrated milk) with different intrinsic compositions, and to predict correct material and energy balances for dairy processes.


Assuntos
Indústria de Laticínios/métodos , Leite/química , Modelos Teóricos , Animais , Manipulação de Alimentos , Temperatura Alta , Temperatura , Termodinâmica , Viscosidade
10.
ISA Trans ; 52(1): 162-9, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23089301

RESUMO

Since the eco-efficiency of all industrial processes/plants has become increasingly important, engineers need to find a way to integrate the control loop configuration and the measurements of eco-efficiency. A new measure of eco-efficiency, the exergy eco-efficiency factor, for control loop configuration, is proposed in this paper. The exergy eco-efficiency factor is based on the thermodynamic concept of exergy which can be used to analyse a process in terms of its efficiency associated with the control configuration. The combination of control pairing configuration techniques (such as the relative gain array, RGA and Niederlinski index, NI) and the proposed exergy eco-efficiency factor will guide the process designer to reach the optimal control design with low operational cost (i.e., energy consumption). The exergy eco-efficiency factor is implemented in the process simulation case study and the reliability of the proposed method is demonstrated by dynamic simulation results.


Assuntos
Algoritmos , Conservação dos Recursos Naturais , Retroalimentação , Indústrias/economia , Indústrias/instrumentação , Modelos Teóricos , Simulação por Computador
11.
ISA Trans ; 51(6): 827-33, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22717392

RESUMO

Software is a powerful tool to help us analyze industrial information and control processes. In this paper, we will show our recently development of a software algorithm/package which can help us select the more eco-efficient control configuration. Nowadays, the eco-efficiency of all industrial processes/plants has become more and more important; engineers need to find a way to integrate control loop configuration and measurements of eco-efficiency. The exergy eco-efficiency factor; a new measure of eco-efficiency for control loop configuration has been developed. This software algorithm/package will combine a commercial simulator, VMGSim, and Excel together to calculate the exergy eco-efficiency factor.


Assuntos
Algoritmos , Conservação dos Recursos Naturais , Transferência de Energia , Indústrias/métodos , Software
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