bluuebunny/crossref_metadata_2025_split huggingface dataset:
On‐line nonlinear model‐based estimation and control of a polymer reactor
Authors: Mutha Rajendra K. , Cluett William R. , Penlidis Alexander 
Published: June 2004

AbstractPolymer reactor control problems often lack frequent measurements of polymer properties, while other reactor environment measurements, such as temperatures, are readily available. The experimental application of a new estimator for handling such multirate measurement systems is presented. The estimator, in conjunction with a detailed nonlinear model and all measurements at their respective sampling rates, is able to provide frequent predictions of the process variables related to the quality (weight‐average molecular weight) and quantity (monomer conversion) of the polymer product. The experimental application of a multivariable, nonlinear model‐based predictive controller using reactor temperature and initiator flow rate as the manipulated variables for controlling weight‐average molecular weight and monomer conversion is presented. The control strategy is designed to handle control nonaffine systems (nonlinear in the manipulated variables), while allowing for the incorporation of rate and amplitude constraints on the manipulated variables. A continuous methyl methacrylate solution polymerization pilot plant was used for the experiment.
Micromachined reactors for catalytic partial oxidation reactions
Authors: Srinivasan Ravi , Hsing I‐Ming , Berger Peter E. , Jensen Klavs F. , Firebaugh Samara L. , Schmidt Martin A. , Harold Michael P. , Lerou Jan J. , Ryley James F. 
Published: June 2004

AbstractSilicon‐based microfabrication of a novel chemical reactor (microreactor) having submillimeter flow channels with integrated heaters, and flow and temperature sensors is described. The potential application of this reactor to partial‐oxidation reactions is explored by using Pt‐catalyzed NH3oxidation as a model reaction. Investigation of reactor behavior as a function of operating conditions shows that conversion and selectivity behavior of conventional laboratory reactors can be reproduced and demonstrates the feasibility of conducting chemical reactions in microfabricated systems. Ignition‐extinction behavior is explored, along with high‐temperature microreactor materials degradation. Potential applications and scale‐up of microreactors are also discussed.
Deflagration and detonation in solid‐solid combustion
Authors: Viljoen Hendrik J. , Hlavacek Vladimir 
Published: June 2004

AbstractSolid‐solid combustion becomes self‐sustaining when the preheating of the fresh mixture is high enough to support a spontaneous chemical reaction. These reactions have high activation energies, requiring significant preheating. Traditionally, conduction has been considered as the main form of preheating, and propagation velocities in the order of a few mm to a few cm per second were found. When acoustic equations are included in the analysis, no significant changes occur for traditional SHS reactions. However, the analysis of a 1‐D model propagating at a constant velocity reveals the existence of two other solutions with propagation velocities which are much faster. An SHS deflagration wave is found with combustion temperature lower than the adiabatic value. The propagation velocity is less than the longitudinal sound speed of the medium, but typical Mach numbers vary between 0.6 and 0.95. The third solution is an SHS detonation with temperature above the adiabatic value and supersonic propagation velocity. Since the heat fluxes are extremely high, the hyperbolic conduction model is used.
Effects of injection location, flow ratio and geometry on kenics mixer performance
Authors: Hobbs D. M. , Muzzio F. J. 
Published: June 2004

AbstractThe performance of the Kenics static mixer for mixing small streams of passive tracer into the bulk flow is investigated as a function of injection location and flow ratio. Flow ratios of 1/99 and 10/90 are simulated at nine different injection locations, and two alternative geometries are considered in addition to the standard Kenics mixer. Mixing is evaluated qualitatively by examining the spread of the tracer on cross‐sectional slices from the mixer and quantitatively by computing the variation coefficient as a function of axial position. For the standard Kenics geometry, injection location strongly affects the extent of mixing only for the first few elements, after which the mixing rate is independent of injection location. In a sufficiently long mixer, material injected at any location spreads to the entire flow, but the least effective injection locations require up to four elements more than the most effective locations to achieve the same variation coefficient. A faster rate of decrease in variation coefficient is observed for a flow ratio of 1/99 us. 10/90. An alternative geometry in which the elements have 120° of twist instead of the standard 180° of twist shows a similar dependence on injection location and flow ratio, but is more energy‐efficient than the standard Kenics geometry. In another alternative geometry in which all elements have the same direction of twist, segregated islands exist in the flow. For injection locations inside the segregated islands, virtually no mixing takes place; for injection locations outside of the segregated islands, the tracer spreads to the remaining flow but does not penetrate the islands.
Plantwide control design procedure
Authors: Luyben Michael L. , Tyreus Bjorn D. , Luyben William L. 
Published: June 2004

AbstractPlantwide control involves the systems and strategies required to control an entire chemical plant consisting of many interconnected unit operations. A general heuristic design procedure is presented that generates an effective plantwide control structure for an entire complex process flowsheet and not simply individual units. The nine steps of the proposed procedure center around the fundamental principles of plantwide control: energy management; production rate; product quality; operational, environmental and safety constraints; liquid‐level and gas‐pressure inventories; makeup of reactants; component balances; and economic or process optimization. Application of the procedure is illustrated with three industrial examples: the vinyl acetate monomer process, the Eastman plantwide‐control process, and the HDA process.
Fundamental continuous‐pulp‐digester model for simulation and control
Authors: Wisnewski Philip A. , Doyle Francis J. , Kayihan Ferhan 
Published: June 2004

AbstractA model of a continuous digester was developed as an extension of the well‐known Purdue model. A lumped‐parameter approximation is used to describe the flow transport mechanism of the digester, and a model based on the fundamental principles of mass and energy is derived. Mass bases and volume fractions are defined to allow fewer simplifying assumptions in the model derivation than in previous model versions. The steady‐state profiles and dynamic responses of the digester model are compared with a previous version of the Purdue model, and the significant differences between the two models are highlighted. The digester model is also compared to the Weyerhaeuser benchmark digester model, and a parametric sensitivity analysis to several model parameters is performed. Physical explanations are given for the demonstrated model behaviors. Model implementation is straightforward, making it useful for process control, optimization and design studies.
New autosomal recessive syndrome with short stature and facio–auriculo–thoracic malformations
Authors: Mégarbané André , Daou Linda , Mégarbané Hala , Cave Hélène , Chouery Eliane , Verloes Alain 
Published: June 2004

AbstractTwo sibs, a boy and a girl, from a Lebanese consanguineous family presented with short stature, microcephaly, ptosis, small, dysplastic, low set ears, short neck, and pectum excavatum and carinatum. In addition, the boy had a high arched palate, a cardiac malformation, and at the X‐rays an absence of fusion of the posterior hemi‐arches of C7 and a fusion between L5 and S1 with a sagittal‐cleft vertebral body of L5, while his sister had a cleft lip/palate and at the X‐rays an abnormal odontoid peg and a malformation of the articular facets between C1 and C2, and bilateral cervical ribs. Other laboratory and radiological investigations were normal. Sequencing of PTPN11 exons 2, 3, 4, 7, 8, 12, and 13 did not reveal any variations. Two other sibs presented almost the same dysmorphic features; one girl died at age 6¼ years after an acute episode of renal insufficiency, and one boy died at 40 days of age. Differential diagnosis is discussed and the possibility of the report of a new autosomal recessive syndrome with variable expressivity is raised. © 2004 Wiley‐Liss, Inc.
Effect of the inclusion of PEG on the solid‐state properties and drug release from polylactic acid films and microcapsules
Authors: Jonnalagadda Sriramakamal , Robinson Dennis H. 
Published: June 2004

AbstractThe use of poly(lactic acid) (PLA) for controlled drug delivery applications was limited by unfavorable physical properties such as hydrophobicity, high intrinsic crystallinity, low permeability, and high glass transition temperatures. This research used polyethylene glycols (PEGs) of varying molecular weights (300–18,500 g/mol) and concentrations (0–50% w/w) to modify the permeability, intrinsic crystallinity, glass transition temperature, residual solvent levels, and release of a model drug, 5‐flurouracil (5FU), from monolithic films and microcapsules fabricated with PLA. The films were fabricated by solvent casting from methylene chloride. The microcapsules were formed by a coacervation method by using a methylene chloride/hexane solvent/nonsolvent system. Compared to PLA films, all PLA : PEG films showed the following: (1) a glass transition temperature between 40 and 55°C, (2) 5–8% lower residual solvent levels, and (3) enhanced permeability to 5FU. These results suggested that the incorporation of PEG improves the physical properties of PLA films to enable fabrication of controlled release delivery systems. Similar to the films, incorporation of PEG also enhanced the permeability of PLA microcapsules to 5FU. However, high intrinsic crystallinity, dual endothermal character for PLA melting, and significant burst release of 5FU in PLA : PEG microcapsules may limit their development for controlled drug delivery applications. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2025–2030, 2004
Reactive microspheres as active fillers for epoxy resins
Authors: Carfagna C. , Ambrogi V. , Cicala G. , Pollicino A. , Recca A. , Costa G. 
Published: June 2004

AbstractPhysical properties of epoxy resins filled with microparticles are presented and discussed. Microparticles were synthesized in the form of micron‐sized, crosslinked spherical particles, with an excess of reactive amino groups on their outer surface, and subsequently blended with EPON828‐3,3′DDS in different weight percents (10 and 20 wt %). Differential scanning calorimetry and scanning electronic microscopy were applied to investigate microsphere properties such as morphology, shape, size, and size distribution. Electron spectroscopy for chemical analysis was applied on particles to relate surface composition and reactivity of microspheres. Rheological, dynamic–mechanical, and mechanical properties of the cured blends were analyzed and related to the pure resin and to the same resin modified with PES180. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 93: 2031–2044, 2004
Chemiluminescence detection of Escherichia coli in fresh produce obtained from different sources
Authors: Mathew Finny P. , Alagesan Deepa , Alocilja Evangelyn C. 
Published: June 2004

AbstractA chemiluminescence‐based assay is developed for the rapid detection of Escherichia coli in fresh produce. The assay was based on the reaction of β‐galactosidase enzyme from E. coli with a phenylgalactosidase‐substituted dioxetane substrate. Light emitted from the reaction was measured in a luminometer and data correlated with counts of E. coli enumerated on sorbitol–MacConkey agar plates. A strain of E. coli O157:H7 was used to inoculate samples of fresh produce to differentiate the inoculum from the natural E. coli potentially present on the produce. Fresh market samples were tested for generic E. coli and E. coli O157:H7. Signiﬁcant differences in light emission were found in samples with high initial E. coli counts when market samples were compared to respective heat‐treated samples. The assay was able to detect E. coli in all produce tested, particularly at higher contamination or inoculation levels. The sensitivity of the assay ranged between 102–105 CFU within 30 min. The chemiluminescence assay provides a simple and rapid method for detection of viable E. coli, an important step towards enhancing food safety. Copyright © 2004 John Wiley & Sons, Ltd.
Damage control in the abdomen and beyond
Authors: Loveland J A , Boffard K D 
Published: June 2004

Abstract

Background
Damage control is not a modern concept, but the application of this approach represents a new paradigm in surgery, borne out of a need to care for patients sustaining multiple high-energy injuries.

Methods
A Medline search was performed to locate English language articles relating to damage control procedures in trauma patients. The retrieved articles were manually cross-referenced, and additional academic and historical articles were identified.

Results and conclusion
Damage control surgery, sometimes known as ‘damage limitation surgery’ or ‘abbreviated laparotomy’, is best defined as creating a stable anatomical environment to prevent the patient from progressing to an unsalvageable metabolic state. Patients are more likely to die from metabolic failure than from failure to complete organ repairs. It is with this awareness that damage control surgery is performed, enabling the patient to maintain a sustainable physiological envelope.
Simultaneous determination of some active ingredients in anti‐viral preparations of traditional Chinese medicine by micellar electrokinetic chromatography
Authors: Chen Xiaofeng , Zhang Jiyou , Xue Chunxia , Chen Xingguo , Hu Zhide 
Published: June 2004

AbstractA simple and rapid micellar electrokinetic chromatography method was developed for the simultaneous determination of quercetin, gentiopicrin, forsythin, chlorogenic acid and caffeic acid in anti‐viral preparations of traditional Chinese medicine (apTCM). In this method, the effects of buffer pH, concentration of the borax and SDS, organic modiﬁers, applied voltage and temperature on the separation were tested and discussed. The results showed that the ﬁve analytes could be well separated within 11 min under conditions of 40 mm borax (pH 9.65) containing 20 mm SDS, 20 kV, at 25°C. In the tested concentration range, regression equations revealed good linear relationships (correlation coefﬁcients 0.9920–0.9991) between the peak areas and corresponding concentrations. In addition, a multiple linear regression QSPR model was constructed to predict the migration times of the analytes and the results were satisfactory. The method was validated by analysis of the ﬁve compounds in three representative apTCM samples with recoveries ranging from 89.2 to 106.6%. Copyright © 2004 John Wiley & Sons, Ltd.
Physiological and intravascular ultrasound assessment of an ambiguous left main coronary artery stenosis
Authors: Leesar Massoud A. , Masden Ronald , Jasti Venu 
Published: June 2004

AbstractThe angiographic assessment of an ambiguous left main coronary artery (LMCA) stenosis is often difficult and not reliable. Intravascular ultrasound (IVUS) and fractional flow reserve (FFR) have improved the diagnostic utility of an ambiguous LMCA stenosis. The combined role of FFR and IVUS in patients with an ambiguous LMCA stenosis is discussed. Catheter Cardiovasc Interv 2004;62:349–357. © 2004 Wiley‐Liss, Inc.
Elective sirolimus‐eluting stent implantation for left main coronary artery disease: Six‐month angiographic follow‐up and 1‐year clinical outcome
Authors: Arampatzis Chourmouzios A. , Lemos Pedro A. , Hoye Angela , Saia Francesco , Tanabe Kengo , van der Giessen Willem J. , Smits Pieter C. , McFadden Eugene , de Feyter Pim , Serruys Patrick W. 
Published: June 2004

AbstractThe effectiveness of sirolimus‐eluting stent (SES) implantation in patients treated electively for left main (LM) stenoses has not been yet ascertained. The present study reports on the clinical and angiographic outcome of 16 consecutive patients treated electively for de novo stenoses in the LM. The impact of SES implantation on major adverse cardiac events was evaluated. Mean age was 65 ± 11 years. Unprotected LM was present in nine (56%), and eight patients (50%) received stents extending into both the left anterior descending and circumflex arteries for stenoses of the distal left main bifurcation. In‐house mortality and reintervention rate was zero. One patient developed a non‐Q‐wave myocardial infarction related to the index procedure. At 1‐year clinical follow‐up, there were no deaths or further myocardial infarctions; one (6%) patient required target lesion revascularization. A total of 12 patients (75%) underwent 6‐month angiographic follow‐up with a late lumen loss of 0.04 ± 0.65 mm and one focal restenosis (8% of patients). Elective SES implantation for LM disease was associated with zero mortality and a very low incidence of additional major adverse events at 1 year. Catheter Cardiovasc Interv 2004; 62:292–296. 2004 Wiley‐Liss, Inc.
Slide‐based cytometry and predictive medicine: The 8th Leipziger workshop and the 1st international workshop on slide‐based cytometry
Authors: Sack Ulrich , Bocsi Jozsef , Tárnok Attila 
Published: June 2004

AbstractSlide‐based cytometry (SBC) and related techniques offer unique tools to perform complex diagnostic procedures at very early disease stages. Multicolor or polychromatic analysis of cells by SBC is of special importance, not only as a cytomics technology platform, but for patients with low blood volume such as neonates. The exact knowledge of the location of each cell on the slide allows the specimen to be restained and subsequently reanalyzed. These separate measurements can be fused to one data file (merging), increasing the information obtained per cell. Relocalization and optical evaluation of the cells, a typical feature of SBC, can be of integral importance for cytometric analysis. Predictive medicine is aimed at the detection of changes in the patient's state prior to the manifestation of deterioration or improvement. Such instances are concerned with multiorgan failure in sepsis or noninfectious posttraumatic shock in intensive care patients, or the pretherapeutic identification of high risk patients in cancer cytostatic therapy. Early anti‐infectious or anti‐shock therapy, as well as curative chemotherapy in combination with stem cell transplantation, may provide better survival chances for the patient as well as concomitant cost containment. Predictive medicine–guided, individualized, early reduction or cessation of therapy may lower or abrogate potential therapeutic side effects (individualized medicine). With the 8th Leipziger Workshop and the 1st International Workshop on Slide‐Based Cytometry, cytomics technologies moved to more practical applications in the clinics and the clinical laboratory. This development will be continued in 2004, at the upcoming Leipziger Workshop and the International Workshop on Slide‐Based Cytometry. © 2004 Wiley‐Liss, Inc.
Quantitative trait loci (QTL) analysis reveals a close linkage between the hinge region and trimeric IgA dominancy in a high IgA strain (HIGA) of ddY mice
Authors: Oida Emi , Nogaki Fumiaki , Kobayashi Ikei , Kamata Tadashi , Ono Takahiko , Miyawaki Shigeki , Serikawa Tadao , Yoshida Haruyoshi , Kita Toru , Muso Eri 
Published: June 2004

AbstractPolymerization of IgA has been suggested as one of the causes of mesangial deposition in IgA nephropathy. HIGA mice are an inbred model of IgA nephropathy, established by selective mating of ddY mice. This strain is characterized by a unique profile of the IgA molecule that is dominantly polymeric and has high serum levels with intense IgA deposition on the mesangium. We carried out quantitative trait loci (QTL) analysis, using F2 generations by crossing HIGA with BALB/c mice. Significant linkage of polymeric IgA in serum samples was identified around D12Mit263, which is close to the gene of the immunoglobulin heavy chain on chromosome 12. The amino acid sequence of the α heavy chain revealed marked differences between BALB/c and HIGA mice. Furthermore, most differences were focussed on the hinge region. The DBA/2J strain, which has the same amino acid sequence in the hinge region as the HIGA strain, also showed polymeric IgA dominance but low IgA levels in sera. Size fraction analysis revealed that these polymeric IgA showed trimer dominance in both DBA/2J and HIGA mice. In conclusion, the hinge region plays a key role in trimeric IgA formation in HIGA mice.
Characterization of HLA‐DR‐ and TCR‐binding residues of an immunodominant and genetically permissive peptide of the 16‐kDa protein of Mycobacterium tuberculosis
Authors: Caccamo Nadia , Meraviglia Serena , La Mendola Carmela , Bosze Szylvia , Hudecz Ferencz , Ivanyi Juraj , Dieli Francesco , Salerno Alfredo 
Published: June 2004

AbstractThe16‐kDa protein of Mycobacterium tuberculosis represents an important antigenic target during bacillary latency and, consequently, should be considered as candidate subunit vaccine component. In this study, we have used CD4 T cell clones that recognize the peptide p91–110, an immunodominant and genetically permissive epitope, in the context of five different HLA‐DR molecules and truncated and substituted variants of this peptide, to identify the minimal binding sequence (HLA‐DR‐binding core) and the minimal stimulatory sequence (TCR‐binding core), as well as the residuesthat contact HLA‐DR molecules and the TCR. We have found a common 9‐mer sequence, spanning amino acids 93–101, as the binding core for HLA‐DR1, ‐DR11, ‐DR13 and ‐DR7, but a longer (13‐mer) sequencespanning amino acids 92–104 was required for binding to the HLA‐DR15 molecules. F93 was required for binding to all the tested HLA‐DR molecules, hence allowing us to identify it as the N‐terminal primary anchor residue (P1). Additionally, the binding requirements for other residues varied considerably between the tested alleles: A94 for HLA‐DR15, V99 for HLA‐DR1, ‐DR15, ‐DR11 and ‐DR7, R100 for HLA‐DR11 and ‐DR13, and L104 for HLA‐DR15. Concerning the residues of p91–110 peptide required for binding to the TCR, the pepscan analysis results would support the contention that P(–1) E92, P6 F98 would be important TCR contact sites because their substitutions led to full loss of T cell activation. Moreover, P8 R100 is found to be critical residue in binding to HLA‐DR11‐ and ‐DR13‐restricted T cell clones, without influencing binding to the relevant HLA‐DR molecule. Our results could be useful to design peptides with altered HLA anchor residues or TCR interaction sites to achieve remarkable increase in activity and to study their vaccine potential.