Engineering Commons^™

Biochemical Characterization Of The Major Sorghum Grain Peroxidase, Mamoudou H. Dicko, Harry Gruppen, Riet Hilhorst, Alphons G. J. Voragen, Willen W. H. Van Berkel

Pr. Mamoudou H. DICKO, PhD

Coupling Between Lysozyme And Trehalose Dynamics: Microscopic Insights From Molecular-Dynamics Simulations, Taner E. Dirama, Joseph E. Curtis, Gustavo A. Carri, Alexei P. Sokolov

Gustavo A. Carri

We have carried out molecular-dynamics simulations on fully flexible all-atom models of the protein lysozyme immersed in trehalose, an effective biopreservative, with the purpose of exploring the nature and extent of the dynamical coupling between them. Our study shows a strong coupling over a wide range of temperatures. We found that the onset of anharmonic behavior was dictated by changes in the dynamics and relaxation processes in the trehalose glass. The physical origin of protein-trehalose coupling was traced to the hydrogen bonds formed at the interface between the protein and the solvent. Moreover, protein-solvent hydrogen bonding was found to control …

Thermoeconomics Of Seasonal Latent Heat Storage System, Yasar Demirel, H.H Ozturk

YASAR DEMIREL

A simple thermoeconomic analysis is performed for a seasonal latent heat storage system for heating a greenhouse. The system consists of three units that are a set of 18 packed-bed solar air heaters, a latent heat storage tank with 6000 kg of technical grade paraffin wax as phase-changing material, and a greenhouse of 180m2. The cost rate balance for the output of a unit is used to estimate the specific cost of exergy for a yearly operation. Based on the cost rate of exergy, fixed capital investment, operating cost, and economic data, approximate cash-flow diagrams have been prepared. The systems …

Preparation Of Conducting Polyaniline/Nylon 6 Blend Fiber By Wet Sppinning Technique, A Mirmohseni, D Salari, Reza Nabavi

Seyed Reza nabavi

No abstract provided.

Assessment Of Thermodynamic Performances For Distillation Columns, Yasar Demirel

YASAR DEMIREL

This study uses the results of converged mass and energy balances and exergy loss profiles by the Aspen Plus simulator to assess the thermodynamic performances of existing continuous distillation columns. Distillation is highly irreversible and energy intensive process. Such an assessment identifies the level of exergy loss due to irreversibility, the avoidable part of exergy loss, and exergy efficiency. The case studies assessed are the separation sections of methanol and vinyl chloride monomer production plants, and a 15-component two-column system. These systems contain two columns in series, which separate multicomponent feeds, produce side products, and operate with integrated process heat …

Non-Isothermal Reaction-Diffusion Systems With Thermodynamically Coupled Heat And Mass Transfer, Yasar Demirel

YASAR DEMIREL

Non-isothermal reaction-diffusion (RD) systems control the behavior of many transport and rate processes in physical, chemical, and biological systems. A considerable work has been published on mathematically coupled nonlinear differential equations of RD systems by neglecting the possible thermodynamic couplings among heat and mass fluxes, and reaction velocities. Here, the thermodynamic coupling refers that a flux occurs without its primary thermodynamic driving force, which may be gradient of temperature, or chemical potential, or reaction affinity. This study presents the modeling equations of non-isothermal RD systems with coupled heat and mass fluxes excluding the coupling of chemical reactions using the linear …

Optimization Of Fed-Batch Saccharomyces Cerevisiae Fermentation Using Dynamic Flux Balance Models, Jared L. Hjersted, Michael A. Henson

Michael A Henson

We developed a dynamic flux balance model for fed-batch Saccharomyces cereVisiae fermentation that couples a detailed steady-state description of primary carbon metabolism with dynamic mass balances on key extracellular species. Model-based dynamic optimization is performed to determine fed-batch operating policies that maximize ethanol productivity and/or ethanol yield on glucose. The initial volume and glucose concentrations, the feed flow rate and dissolved oxygen concentration profiles, and the final batch time are treated as decision variables in the dynamic optimization problem. Optimal solutions are generated to analyze the tradeoff between maximal productivity and yield objectives. We find that for both cases the …

Kaedah Analitik Untuk Penentuan Ciri-Ciri Terpilih Bagi 3-Hidroksipropionaldehyde, Chuen-Tat Kang

Kang Chuen Tat (江俊达)

3-hidroksipropionaldehyde (HPA) merupakan metabolit peralihan bagi metabolisma gliserol ke arah pembentukan 1,3-propanediol. Voisenet (1910) sebenarnya telah memerhatikan bahawa bahan tersebut dan pembentukannya dari gliserol ketika pemusnahan win oleh bakteria walaupun 3-HPA merupakan sejenis antibiotik dan bahan pemula bagi plastik berkualiti tinggi, namun masih belum ada data analitik yang lengkap untuk bahan tersebut. Merujuk kepada data eksperimen bagi kertas ini, penggunaan 2-H untuk analisis NMR menunjukkan bahawa ikatan –CHO boleh diperhatikan pada δ9.5, RCH3 pada δ1.37, R2CH2 pada δ3.68, R3CH pada δ1.9 dan sebagainya. Spektrum NMR bagi karbon-13 menunjukkan enam petunjuk, pada shif kimia 40.1, 46.3, 56.2, 58.7, 89.7, dan 207.7 …

Optimization Of The Thermal Utilisation Of Sewage Sludge In An Installation With A Bubbling Fluidised Bed Reactor, Jerzy Baron, Malgorzata Olek, Witold Zukowski

Witold Zukowski

Tests on the burning sewage sludge so as to minimise the emissions of CO, NOx and dust are described. The fluidised bed process used sewage sludge with 50 - 80% of water together with wood chips. The results obtained indicate that the NOx concentration in the flue gases can be reduced by controlling the fuel/air ratio. The conditions can be optimised by using sufficiently high temperatures and keeping the CO concentration down. It is proposed that the quality of the operation of the installation should be assessed by means of a dimensionless parameter, the toxicity index and supporting evidence is …

Small Scale Biomass Incinerator With A Bubbling Fluidised Bed. Ii. Combustion Of Feathers And Mbm, Jerzy Baron, Stanislaw Kandefer, Malgorzata Olek, Malgorzata Pilawska, Witold Zukowski

Witold Zukowski

The paper presents the results from a study of the combustion of wastes of animal origin - feathers and meat and bone meal in a 1.5 MW bubbling fluidised bed reactor. The process of thermal utili-sation is stable and short - term fluctuations on the composition of the wastes are not a problem, since the operational parameters of the combustor are constantly monitored and controlled. The process does not require conventional supporting fuel and the level of CO in the flue gases is com-parable to that observed with some low quality coals, but NOx and SO2 emissions are present, because …

Distribution Of Heavy Metals Between Gas, Liquid And Solid Wastes From Sewage Sludge Combustion, Jerzy Baron, Witold Zukowski, Stanislaw Kandefer

Witold Zukowski

Results are presented on the partitioning of metals between the different waste streams produced from the co-combustion of sewage sludge with wood chips in an installation with a bubbling fluidised be combustor, equipped with a flue gas cleaning system. The system consisted of a dust separator and two wet scrubbers in series. For selected metals, their concentrations were determined in the fuel and in the ashes as well as carried with the flue gas stream. Heavy metals were mostly found in the dust carried with the flue gases, either as vapours condensing on solid surfaces or present in the fines …