bluuebunny/crossref_metadata_2025_split huggingface dataset:
Relation between Citric Acid Production and Respiration Rate of Aspergillus niger in Solid‐State Fermentation
Authors: Prado F.C. , Vandenberghe L.P.S. , Lisboa C. , Paca J. , Pandey A. , Soccol C.R. 
Published: April 2004

AbstractAmong the organic acids produced industrially, citric acid is the most important in quantitative terms. Solid‐state fermentation (SSF) has been an alternative method for citric acid production using agro‐industrial residues such as cassava bagasse (CB). The use of CB as a substrate can avoid environmental problems caused by its disposal into the environment. This study was developed to verify the influence of the treated bagasse amount, and consequently, the influence of the gelatinization degree of CB starch on citric acid production by SSF in Erlenmeyer flasks, horizontal drums, and trays. The best results were obtained in a horizontal drum bioreactor using 100 % of treated CB. However, trays showed advantages and good perspectives for large‐scale citric acid production due to economic reasons such as energy costs. A kinetic study was also carried out in order to compare citric acid production in glass columns (laboratory scale) and horizontal drum bioreactors (semi‐pilot scale). This study was accomplished in order to follow the influence of aeration on citric acid accumulation. In addition, the production of CO2 was evaluated as an indirect method of biomass estimation. Citric acid production was higher in glass columns (309.70 g/kg of dry CB) than in HD bioreactors (268.94 g/kg of dry CB). Finally, it was possible to show that citric acid production was favored by a limited biomass production, which occurred with low aeration rates. Biomass production is related to CO2 production and as a result, a respirometry analysis could be used for biomass estimation.
Biofiltration of Butyl Acetate and Xylene Mixtures Using a Trickle‐Bed Air Biofilter
Authors: Lu C. , Chang K. 
Published: April 2004

AbstractButyl acetate and xylene mixtures are commonly encountered from the manufacture of semi‐conductor or opto‐electronic apparatuses. The release of these substances into the ambient air may have a negative effect on the air quality. This study attempts to employ a trickle‐bed air biofilter for treating butyl acetate and xylene mixtures under different gas flow rates and influent concentrations. Almost complete VOC removal could be attained with influent carbon loadings of BA (butyl acetate) and X (xylene) below 40 and 15 g/m3h, respectively. As the influent carbon loadings of BA and X were increased up to 150 and 110 g/m3h, removal efficiencies higher than 80 % were achieved. Therefore, the trickle‐bed air biofilter (TBAB) appeared efficient in the control of emissions containing mixtures of butyl acetate and xylene with low to medium carbon loadings. The removal efficiencies of butyl acetate were higher than those of xylene, indicating that butyl acetate was the substrate preferred in the utilization of butyl acetate and xylene mixtures by the microorganisms. Carbon recoveries of 98–101 % were achieved, demonstrating the accuracy of results. The carbon mass rate of the liquid effluent was approximately two to three orders of magnitude less than that of the CO2 effluent, indicating that the dissolved VOCs and their derivatives in the leachate were present in a negligible amount in the reactor. Applicable operating conditions of the TBAB unit for treating BA and X mixtures were suggested.
Aeolian modification of moraine soils, Whiskey Basin, Wyoming, USA
Authors: Applegarth Michael T. , Dahms Dennis E. 
Published: April 2004

AbstractSoils along catenas of Pinedale (15–20 ka) and Bull Lake (100–130 ka) age moraines at Whiskey Basin in the Wind River Range, Wyoming, USA, were sampled to assess the effects of aeolian processes on soil development here. Aeolian processes appear to have inﬂuenced soils by both depositing sediments and eroding topsoils. Pedogenic silt (often used as an indicator of wind deposition) accumulated in the Bull Lake soils moderately correlate with pedogenic clay accumulated, suggesting that ﬁne sediments may have been deposited and incorporated into soil formation here. Following removal of previous topsoil by wind during Pinedale glaciation, Bull Lake B horizons have developed into contemporary A horizons. These data further link aeolian processes to soil development on piedmont moraines throughout the Wind River Range. Copyright © 2004 John Wiley & Sons, Ltd.
A hillslope hydrology approach for catchment‐scale slope stability analysis
Authors: Hennrich Kirsten , Crozier Michael J. 
Published: April 2004

AbstractRegional analysis of slope stability is often constrained by availability of data. Model requirements for input data cannot be met at the desired spatial resolution because data are either site‐speciﬁc or non‐existent. Faced with these difﬁculties it has often been the practice to assume that certain parameters are uniform throughout the area of interest. An alternative approach proposed here allows a more detailed discrimination of slope stability conditions. Based on the principles of hillslope hydrology, hydrologic information can be generated at sufﬁcient resolution to allow higher resolution slope stability analysis. Measurements from an instrumented network in a small area have been used to establish index‐based models for topographic and climate‐related controls of piezometric response. The ability to relate groundwater levels to rainfall and topographic parameters provides a means of up‐scaling to larger catchments and ultimately the opportunity to generate a catchment‐wide prediction of the distribution, magnitude and frequency of rainstorm‐generated groundwater levels. The example provided in this study uses the topography index of TOPMODEL in GIS to predict the spatial patterns of groundwater elevation for seasonal soil moisture conditions and given rainfall inputs. This allows modelling of catchment‐wide response of soil water to rainstorms with different return periods (representing different magnitudes), and is an essential prerequisite for a probabilistic regional slope stability analysis. Copyright © 2004 John Wiley & Sons, Ltd.
System capacity with smart antennas under the presence of angular power spread
Authors: Muñoz‐Rodríguez David , Orozco Edgar , Vargas Cesar , Rodríguez‐Cruz José Ramón , Donis Gerardo 
Published: April 2004

AbstractSmart antennas are a suitable technology to increase the capacity of cellular systems. However, under severe channel conditions, the capacity gain may be small. This work presents a general methodology for the analysis of the effect of the angular power dispersion on the capacity gain for a CDMA system when using smart antennas. System capacity is expressed in terms of a supportable mean number of subscribers per angular sector and it is shown that maximum and mean number of subscribers criteria can be considered equivalent. Formulations for a single cell as well as for multi‐tier scenarios are presented. Omni‐directional case and non‐spread scenarios are shown to be particular cases of the methodology introduced. Capacity is determined for a smart antenna system, both for general antenna beam patterns and general spread characteristics. Copyright © 2004 AEI
In‐band coding technique to promptly enhance SDH/SONET fiber‐optic channels with FEC capabilities
Authors: Tychopoulos Afxendios , Koufopavlou Odysseas 
Published: April 2004

AbstractIn the present paper, we discuss FEC‐methods for SDH/SONET networks under the perspective of DWDM. The lightwave channels are assumed to have a burst‐error character. First, a FEC‐strategy is outlined by means of fundamental performance criteria. The SDH/SONET frame‐overhead is also explored for possible allocation of error‐correction bits inside. Then, different FEC methods are rated by the above criteria in a systematic manner. We eventually propose a section‐ and line‐layer, in‐band coding (IBC) approach that should deal with a very wide range of optical network applications in a straightforward, uniform and effective fashion. Comparison with past work on this subject reveals clear advantages. Extensive simulations, implementation and laboratory measurements prove the feasibility and efficiency of the proposed FEC method with RS(244,240,9), provided that a portion of the SDH/SONET overhead is available. Copyright © 2004 AEI
A new mutual authentication and key exchange protocol with balanced computational power for wireless settings
Authors: Yang Chou‐Chen , Li Jian‐Wei , Hwang Min‐Shiang 
Published: April 2004

AbstractMutual authentication and key exchange protocols (MAKEP) provide two parties in communication with guarantee of true identity. And then the two parties end up sharing a common session key for privacy and data integrity during the session. In MAKEP, public‐key‐based schemes and symmetric‐key‐based schemes are often used. However, the former requires high computation complexity and hence, it is not suitable for applications in wireless settings. The latter has to maintain many distinct keys for different parties. Wong et al. proposed the Linear MAKEP to solve these problems. But in term of storage space, it is not optimal. In this paper, we propose a scheme that uses the geometric properties of line to achieve mutual authentication and key exchange. Compared with Wong et al.'s scheme, our scheme is efficient and requires less storage space. It can withstand the replay attack and the unknown key‐share attack, and the server does not bear much more computation cost than the client in each session, hence we call it a protocal with balanced computational power. Copyright © 2004 AEI
Construction, analysis and performance of generalised woven codes
Authors: Bossert Martin , Dieterich Hans , Schnug Walter , Shavgulidze Sergo 
Published: April 2004

AbstractGeneralised woven codes (WC) are constructed by combining the woven code structure with the idea of generalised concatenated codes, also known as multi‐level codes. The required nested inner convolutional code is analysed. The encoder structure of this new class of codes is described and fundamental code parameters are derived. It is shown that generalised WC have a free distance which is superior to that of comparable WC. Several iterative and non‐iterative decoding strategies are discussed. It is shown that the decoding complexity of the nested inner code is not larger than the decoding complexity of its mother code. Finally, bit error rates obtained from simulations are discussed and compared with other code structures like WC. Copyright © 2004 AEI
Performance analysis of integrated voice and multiple classes of data with a finite number of sessions
Authors: Mahdavi M. , Edwards R. M. , Ivey P. 
Published: April 2004

AbstractThis paper discusses a TDM multi‐access channel that supports hybrid switching including circuit switched voice and packet switched data asKCclasses with a finite number of open sessions. The channel is partitioned intoKCsub‐channels that are assigned to classes. Applications are hybrid switching in mobile TDMA (e.g. GSM/GPRS cellular networks) and time division multiplexing systems. Herein, an original analysis for such mixed services is derived. In this paper, a new Markov model for voice traffic in each sub‐channel is shown. The system is modelled with an irreducible continuous time and aperiodic Markov process and a non‐homogenous finite QBD process based on macrostructure model of TDM channel is derived. A novel computational algorithm is then formulated. Using the computational algorithm, performance metrics of the system such as mean delay in the queue as well as average number of data users in queue will be obtained. QoS is defined and the advantage of channel sharing is highlighted. Numerical results are corroborated by simulation. Copyright © 2004 AEI
Hybrid location systems: delivering non‐standardized assistance data in GSM/GPRS networks
Authors: Martin‐Escalona Israel , Barceló Francisco , Paradells Josep 
Published: April 2004

AbstractHybrid location systems overcome some of the limitations of location techniques when they are used as standalone. Coverage and accuracy improve when hybridization is carried out by combining time measurements prior to determining location co‐ordinates, rather than mixing position co‐ordinates. However, for the best performance, certain hybridization methods need to transmit assistance data that are not included in current location protocols and standards. This assistance information includes data that may be used to synchronize the different positioning systems for hybridization. This study introduces two proposals that allow the required assistance information to be delivered from the network to the terminal without changing the existing standards. Both proposals are discussed in detail and compared. Copyright © 2004 AEI
Perceptual Evaluation of JPEG2000
Authors: Samet Amine , Ben Ayed Mohamed Ali , Loulou Mourad , Masmoudi Nouri 
Published: April 2004

AbstractWith the increasing usage of multimedia technologies, image compression requires higher performances as well as new features. To address these needs in the specific area of continuous tone still image encoding, a new standard is currently being developed, the JPEG2000. It is not only intended to provide rate‐distortion and subjective image quality performance superior to existing standards, but also to provide new features and functionalities that current standards can either not address them efficiently or in many cases cannot address them at all. Copyright © 2004 AEI
Numerical simulations of large falling drops
Authors: Gottesdiener Louis , Gueyffier Denis , Abdelouahab Mohammed , Gatignol Renée , Zaleski Stéphane 
Published: April 2004

AbstractThe numerical simulation in a two‐phase medium of falling drops allows their velocities and shapes during the fall to be calculated. The terminal velocities and shapes for bromoform and chlorobenzene drops falling into water have been obtained. Although the method used calculates the flow inside and around the drop, it has not been possible to give results independent of the spatial discretization and the boundary effects. However, taking these influences into account, the numerical results agree with the experimental data given and the study consists of a good validation of the SURFER code used. Copyright © 2004 John Wiley & Sons, Ltd.
A projection scheme for incompressible multiphase flow using adaptive Eulerian grid
Authors: Chen T. , Minev P. D. , Nandakumar K. 
Published: April 2004

AbstractThis paper presents a finite element method for incompressible multiphase flows with capillary interfaces based on a (formally) second‐order projection scheme. The discretization is on a fixed Eulerian grid. The fluid phases are identified and advected using a level set function. The grid is temporarily adapted around the interfaces in order to maintain optimal interpolations accounting for the pressure jump and the discontinuity of the normal velocity derivatives. The least‐squares method for computing the curvature is used, combined with piecewise linear approximation to the interface. The time integration is based on a formally second order splitting scheme. The convection substep is integrated over an Eulerian grid using an explicit scheme. The remaining generalized Stokes problem is solved by means of a formally second order pressure‐stabilized projection scheme. The pressure boundary condition on the free interface is imposed in a strong form (pointwise) at the pressure‐computation substep. This allows capturing significant pressure jumps across the interface without creating spurious instabilities. This method is simple and efficient, as demonstrated by the numerical experiments on a wide range of free‐surface problems. Copyright © 2004 John Wiley & Sons, Ltd.
Mesh adaptation as a tool for certified computational aerodynamics
Authors: Schall E. , Leservoisier D. , Dervieux A. , Koobus B. 
Published: April 2004

AbstractMesh convergence order is a key for certification of the accuracy of numerical solutions. A few available results and tools in mesh adaption are synthetized in order to specify a mesh converging method for adaptive calculation of compressible flows including shocks or viscous layers. The main design property for this method is early second‐order convergence, where early means that the second‐order convergence is obtained with coarse meshes. Copyright © 2004 John Wiley & Sons, Ltd.
A projection method for solving incompressible viscous flows on domains with moving boundaries
Authors: Pan Hua , Pan Lun Sheng , Xu Diao , Ng Teng Yong , Liu Gui Rong 
Published: April 2004

AbstractIn this paper, a projection method is presented for solving the flow problems in domains with moving boundaries. In order to track the movement of the domain boundaries, arbitrary‐Lagrangian–Eulerian (ALE) co‐ordinates are used. The unsteady incompressible Navier–Stokes equations on the ALE co‐ordinates are solved by using a projection method developed in this paper. This projection method is based on the Bell's Godunov‐projection method. However, substantial changes are made so that this algorithm is capable of solving the ALE form of incompressible Navier–Stokes equations. Multi‐block structured grids are used to discretize the flow domains. The grid velocity is not explicitly computed; instead the volume change is used to account for the effect of grid movement. A new method is also proposed to compute the freestream capturing metrics so that the geometric conservation law (GCL) can be satisfied exactly in this algorithm. This projection method is also parallelized so that the state of the art high performance computers can be used to match the computation cost associated with the moving grid calculations. Several test cases are solved to verify the performance of this moving‐grid projection method. Copyright © 2004 John Wiley Sons, Ltd.
An accurate moving grid Eulerian Lagrangian localized adjoint method for solving the one‐dimensional variable‐coefficient ADE
Authors: Younes Anis 
Published: April 2004

AbstractAn accurate finite‐volume Eulerian Lagrangian localized adjoint method (ELLAM) is presented for solving the one‐dimensional variable coefficients advection dispersion equation that governs transport of solute in porous medium. The method uses a moving grid to define the solution and test functions. Consequently, the need for spatial interpolation, or equivalently numerical integration, which is a major issue in conventional ELLAM formulations, is avoided.After reviewing the one‐dimensional method of ELLAM, we present our strategy and detailed calculations for both saturated and unsaturated porous medium. Numerical results for a constant‐coefficient problem and a variable‐coefficient problem are very close to analytical and fine‐grid solutions, respectively. The strength of the developed method is shown for a large range of CFL and grid Peclet numbers. Copyright 2004 John Wiley & Sons, Ltd.
Numerical approximation of optimal control of unsteady flows using SQP and time decomposition
Authors: Ravindran S. S. 
Published: April 2004

AbstractIn this paper, we present numerical approximations of optimal control of unsteady flow problems using sequential quadratic programming method (SQP) and time domain decomposition. The SQP method is considered superior due to its fast convergence and its ability to take advantage of existing numerical techniques for fluid flow problems. It iteratively solves a sequence of linear quadratic optimal control problems converging to the solution of the non‐linear optimal control problem. The solution to the linear quadratic problem is characterized by the Karush–Kuhn–Tucker (KKT) optimality system which in the present context is a formidable system to solve. As a remedy various time domain decompositions, inexact SQP implementations and block iterative methods to solve the KKT systems are examined. Numerical results are presented showing the efficiency and feasibility of the algorithms. Copyright © 2004 John Wiley & Sons, Ltd.
Effect of low‐zinc status and essential fatty acids deficiency on the activities of aspartate aminotransferase and alanine aminotransferase in liver and serum of albino rats
Authors: Ajayi Olubunmi Bolanle , Odutuga Adewale 
Published: April 2004

AbstractThe effects of dietary deficiencies of zinc and essential fatty acids (EFAs) or both on aspartate aminotransferase (AST) and alanine aminotransferase (ALT) were investigated in young growing rats. Four groups of albino rats were fed diets deficient in either EFA (4% hydrogenated coconut oil) or zinc (6 ppm) or both. The control diet was adequate in EFA (4% soybean oil) and zinc (100 ppm). The feeding trial lasted eight weeks and the activities of AST and ALT were determined in the liver and serum. EFA deficiency had no significant (p > 0.05) effect on liver AST. However, zinc and the double deficiencies depressed AST activity in the organ. Deficiencies of EFA, zinc and their combination depressed ALT activity in the liver significantly (p < 0.05) with a concomitant increase recorded in the serum. The data suggested alteration in endothelial permeability of the plasma membrane and thus leakage of membrane constituents in the tissue studied. It is therefore considered that these deficient diets may affect liver tissue negatively in view of the role of these enzymes in amino acid metabolism.
Nutritional value of broad bean seeds. Part 3: Changes of dietary fibre and starch in the production of commercial flours
Authors: Giczewska Anna , Borowska Julitta 
Published: April 2004

AbstractWe report on the impact of flour production from small‐ and large‐seed varieties of broad bean on the quantitative and qualitative distribution of dietary fibre and starch. The experimental material consisted of the seeds of small‐seed varieties of broad bean: Gobik and Goral, large‐seed varieties of broad bean: Windsor Bialy and Bartom, and pea seeds of Albatros, Karat and Miko varieties (for comparison). The seeds were at full physiological maturity. Soaking and hydrothermal processing were shown to cause multidirectional, statistically significant changes in dietary fibre and starch, depending on both parameters of the process and type of the seeds. The flours of both small‐seed broad bean varieties contained 20.15%–28.31%, flours of the large‐seed broad bean 23.10%–27.50%, and those from pea seeds 20.13%–22.81% total dietary fibre. Attention should be paid to the considerable, approximately 2‐fold increase in the soluble dietary fibre (SDF) content, compared to the raw material. The processing of seeds caused significant changes also with reference to starch. The most considerable changes were observed when the variant with the longest times of soaking (18 h) and heating (45 min) was applied. In the broad bean flours, the content of analytically available starch decreased by 22.94–30.60% and its digestibility was observed to decrease up to 30.25%. The pea flours, however, were characterised by an increased concentration of both forms of starch, especially significant for the digestible starch. The calculated content of resistant starch (RS) differentiated, to a high extent, the flours obtained. Under the same processing conditions, the flours of small‐seed Gobik and Goral varieties of broad bean were characterised by a significantly higher RS content than those obtained from the large‐seed varieties. A decrease in the starch digestibility rate index (SDRI) values, especially high for the small‐seed varieties, should also be emphasised. The results obtained indicate that the nutritional value of flours can be determined by controlled processing parameters.