bluuebunny/crossref_metadata_2025_split huggingface dataset:
Potassium and Potassium Alloys
Authors: Burkhardt Elizabeth R. 
Published: December 2006

AbstractThe article contains sections titled:1.Potassium1.1.Properties1.2.Production1.3.Handling and Occupational Safety2.Potassium Alloys2.1.Properties of NaK Alloy2.2.Production of NaK Alloy2.3Handling and Occupational Safety of NaK Alloy3.Uses of Potassium and Potassium Compounds3.1.Potassium and NaK Alloy3.2.Potassium Hydride3.3.Potassium Bases3.3.1Potassium Alkoxides3.3.2Potassium Amides3.4.Potassium Superoxide4.AcknowledgementPotassium is the third element in the alkali metal group. This highly reactive metal is used to make potassium superoxide for use in self‐contained breathing apparatus. Potassium in the form of alloys with sodium is used in industrial synthesis of alkylated aromatic hydrocarbons such as isobutylbenzene. Compounds of potassium derived from alcohols and amines are routinely used as bases in pharmaceutical and agricultural synthesis.
Sulfur
Authors: Nehb Wolfgang , Vydra Karel 
Published: December 2006

AbstractThe article contains sections titled:1.Introduction2.Historical Background3.Properties3.1.Physical State3.2.Viscosity3.3.Other Physical Properties3.4.Chemical Properties4.Raw Materials for Sulfur Production4.1.Elemental Sulfur Resources4.2.Sulfide Ores4.3.Fossil Fuels4.4.Sulfates5.Production from Native Deposits5.1.Flotation5.2.Melting Out5.3.Distillation5.4.Flotation with Melting Out5.5.The Frasch Process5.5.1.Structure of “Fraschable” Sulfur Deposits5.5.2.Outline of the Process5.5.3.Sulfur Purity5.5.4.Energy Consumption5.5.5.The U.S. Frasch Industry5.5.6.The Mexican Frasch Industry6.The Claus Process6.1.Occurrence of Hydrogen Sulfide6.2.Hydrogen Sulfide Removal from Gases6.3.History of the Claus Process6.4.Chemistry of the Claus Process6.5.Claus Plant Configurations6.6.The Claus ‐ Oxygen Process6.7.Troubleshooting6.8.Optimization of Sulfur Recovery Units by Use of Analyzers7.Increased Sulfur Recovery7.1.Selective Oxidation7.1.1.The Superclaus Process, the Euroclaus®Process7.1.2.The Recycle Selectox Process7.1.3.The Once‐Through Selectox Process7.2.Tail Gas Treatment7.2.1.Sub‐Dewpoint Processes7.2.1.1.The Sulfreen, Hydrosulfreen, and Doxosulfreen Processes7.2.1.2.The CBA Process7.2.1.3.The MCRC Process7.2.2.Processes Working on Reduced Tail Gases7.2.2.1.The SCOT and Super‐SCOT Processes7.2.2.2.The Sulften Process7.2.2.3.Solvents for Regenerative H2S Removal7.2.2.4.The BSR/Selectox Process7.2.3.Processes Working on Oxidized Tail Gas7.2.3.1.The Wellman ‐ Lord Process7.2.3.2.The Clintox Process7.2.4.Biodesulfurization; Thiopaq Process7.3.Purification7.3.1.Arsenic and Selenium Removal7.3.2.Melting of Stretford Sulfur7.3.3.Degassing of Claus Sulfur7.4.Sulfur Management; the OmniSulf Process8.Gas‐Phase Reduction of Sulfur Dioxide8.1.The Allied Chemicals Process8.2.Other Processes with Gas as Reducing Agent8.3.Processes with Coke or Coal as Reducing Agent9.Commercial Grades and Forms of Sulfur9.1.Quality9.2.Commercial Forms for Bulk Transport9.2.1.Dry Bulk Sulfur9.2.2.Liquid Sulfur9.2.3.Formed Sulfur9.2.3.1.Slating9.2.3.2.Wet Pelletizing (Water Prilling)9.2.3.3.Air Prilling9.2.3.4.Other Prilling Processes9.2.3.5.Drum Granulation: The Procor GX Process9.2.3.6.Spouted Bed Granulation9.3.Special Forms and Grades10.Uses10.1.Agriculture10.2.Construction Materials10.3.Sulfur‐Containing Batteries10.4.Other Potential Uses
Mathematics in Chemical Engineering
Authors: Finlayson Bruce A. , Biegler Lorenz T. , Grossmann Ignacio E. 
Published: December 2006

Abstract
The article contains sections titled:

1.

Solution of Equations

1.1.

Matrix Properties

1.2.

Linear Algebraic Equations

1.3.

Nonlinear Algebraic Equations

1.4.

Linear Difference Equations

1.5.

Eigenvalues

2.

Approximation and Integration

2.1.

Introduction

2.2.

Global Polynomial Approximation

2.3.

Piecewise Approximation

2.4.

Quadrature

2.5.

Least Squares

2.6.

Fourier Transforms of Discrete Data

2.7.

Two‐Dimensional Interpolation and Quadrature

3.

Complex Variables

3.1.

Introduction to the Complex Plane

3.2.

Elementary Functions

3.3.

Analytic Functions of a Complex Variable

3.4.

Integration in the Complex Plane

3.5.

Other Results

4.

Integral Transforms

4.1.

Fourier Transforms

4.2.

Laplace Transforms

4.3.

Solution of Partial Differential Equations by Using Transforms

5.

Vector Analysis

6.

Ordinary Differential Equations as Initial Value Problems

6.1.

Solution by Quadrature

6.2.

Explicit Methods

6.3.

Implicit Methods

6.4.

Stiffness

6.5.

Differential ‐ Algebraic Systems

6.6.

Computer Software

6.7.

Stability, Bifurcations, Limit Cycles

6.8.

Sensitivity Analysis

6.9.

Molecular Dynamics

7.

Ordinary Differential Equations as Boundary Value Problems

7.1.

Solution by Quadrature

7.2.

Initial Value Methods

7.3.

Finite Difference Method

7.4.

Orthogonal Collocation

7.5.

Orthogonal Collocation on Finite Elements

7.6.

Galerkin Finite Element Method

7.7.

Cubic B‐Splines

7.8.

Adaptive Mesh Strategies

7.9.

Comparison

7.10.

Singular Problems and Infinite Domains

8.

Partial Differential Equations

8.1.

Classification of Equations

8.2.

Hyperbolic Equations

8.3.

Parabolic Equations in One Dimension

8.4.

Elliptic Equations

8.5.

Parabolic Equations in Two or Three Dimensions

8.6.

Special Methods for Fluid Mechanics

8.7.

Computer Software

9.

Integral Equations

9.1.

Classification

9.2.

Numerical Methods for Volterra Equations of the Second Kind

9.3.

Numerical Methods for Fredholm, Urysohn, and Hammerstein Equations of the Second Kind

9.4.

Numerical Methods for Eigenvalue Problems

9.5.

Green's Functions

9.6.

Boundary Integral Equations and Boundary Element Method

10.

Optimization

10.1.

Introduction

10.2.

Gradient Based Nonlinear Programming

10.3.

Optimization Methods without Derivatives

10.4.

Global Optimization

10.5.

Mixed Integer Programming

10.6.

Dynamic Optimization

10.7.

Development of Optimization Models

11.

Probability and Statistics

11.1.

Concepts

11.2.

Sampling and Statistical Decisions

11.3.

Error Analysis in Experiments

11.4.

Factorial Design of Experiments and Analysis of Variance

12.

Multivariable Calculus Applied to Thermodynamics

12.1.

State Functions

12.2.

Applications to Thermodynamics

12.3.

Partial Derivatives of All Thermodynamic Functions
Liquid–Solid Extraction
Authors: Voeste Theodor , Weber Klaus , Hiskey Brent , Brunner Gerd 
Published: December 2006

AbstractThe article contains sections titled:1.Introduction2.Extraction without Chemical Reaction2.1.General Comments2.2.Technical Principles and Process Design2.3.Extraction Processes and Typical Equipment2.3.1.Batch Extraction2.3.2.Continuous Extraction3.Chemical Leaching in Hydrometallurgy3.1.Methods3.2.Principles3.3.Typical Processes and Equipment3.3.1.Agitation Leaching of an Oxidized Gold Ore3.3.2.Pressure Leaching of Zinc Sulfide Concentrates3.3.3.Bioleaching of Refractory Precious‐Metal Concentrates4.Extraction with Supercritical Fluids4.1.Principles4.2.Process Design4.3.Equipment
Aerogels
Authors: Hüsing Nicola , Schubert Ulrich 
Published: December 2006

Abstract
The article contains sections titled:

1.

Introduction

2.

Synthesis

2.1.

Network Formation and Structure

2.1.1.

Inorganic Aerogels

2.1.1.1.

SiO
2
Aerogels

2.1.1.2.

Metal Oxide Aerogels

2.1.2.

Inorganic/Organic Hybrid Aerogels

2.1.3.

Organic Aerogels

2.2.

Drying Methods

2.2.1.

Supercritical Drying

2.2.1.1.

Drying in Organic Solvents

2.2.1.2.

Supercritical Drying with CO
2

2.2.2.

Freeze Drying

2.2.3.

Ambient Pressure Drying

2.3.

Modification of Aerogels after Drying

3.

Properties

3.1.

Structural Properties

3.2.

Physical and Chemical Properties

3.2.1.

Optical Properties

3.2.2.

Mechanical and Acoustic Properties

3.2.3.

Thermal Conductivity

3.2.4.

Hydrophobicity

4.

Applications

4.1.

Çerenkov Detectors

4.2.

Thermal Insulation

4.3.

Catalysis

4.4.

Application as Storage Media

4.5.

Electrical and Electronic Applications

4.6.

Acoustic and Mechanical Applications

4.7.

Optical Applications

4.8.

Other Applications

5.

Future Perspectives

Aerogels are unique among solid materials. They have extremely low densities (up to 95 % of their volume is air), large open pores, and a high inner surface area. This combination of properties results in interesting physical properties, e.g., for silica aerogels extremely low thermal conductivities and low sound velocities are combined with optical transparency. Aerogels are typically prepared via wet chemical processes, such as sol – gel processing, and thus their pore system is initially filled with liquid. Only special drying techniques allow for exchange of the pore liquid against air while maintaining the filigrane solid framework. The most common drying technique is supercritical extraction, and sometimes chemical modification of the inner surface can be used to facilitate drying. The structure of the gel network, and thus the physical properties of aerogels, decisively depends on the choice of the precursors and the chemical reaction parameters for preparing the gels. Therefore, the later materials properties can be deliberately designed in the starting reaction solution.
On‐Line Monitoring of Chemical Reactions
Authors: Hergeth Wolf‐Dieter 
Published: December 2006

AbstractThe article contains sections titled:1.Introduction2.Reaction Calorimetry2.1.Introduction2.2.Heat Flow Balance and Principles of Measurement2.2.1.Heat Flow Balance2.2.2.Basic Modes of Operation2.3.Applications and Instrumentation3.Ultrasonic Methods3.1.Introduction3.2.Theory3.3.Applications4.Dielectric Spectroscopy4.1.Theory and Mechanisms4.2.Instrumentation and Applications5.Optical Spectroscopy5.1.Introduction5.2.Instrumentation for Reaction Monitoring5.3.Applications of Optical Spectroscopy5.3.1.UV – VIS Spectroscopy5.3.2.NIR Spectroscopy5.3.3.IR Spectroscopy5.3.4.Raman Spectroscopy5.3.5.Fluorescence5.3.6.Other Spectroscopic Techniques6.Particle Size Analysis6.1.Scattering Techniques6.1.1.Turbidimetry6.1.2.Angular Static Light Scattering6.1.3.Dynamic Light Scattering6.1.4.Other Optical Techniques6.2.Separation Techniques7.Chromatography7.1.Introduction7.2.GC Hardware Components7.3.Applications of Gas Chromatography7.4.Other Chromatographic Techniques8.Electroanalytical Methods8.1.Introduction8.2.Conductometry8.3.Potentiometry8.4.Amperometry, Voltammetry, and Coulometry9.Miscellaneous Methods9.1.Mass Spectrometry9.2.Densimetry and Dilatometry9.3.Rheometry9.4.NMR Spectroscopy
Design of Poly(vinyldiaminotriazine)‐Based Nonviral Vectors via Specific Hydrogen Bonding with Nucleic Acid Base Pairs
Authors: Cao Z. Q. , Liu W. G. , Liang D. C. , Guo G. , Zhang J. Y. 
Published: December 2006

AbstractA novel gene transfer system that complexes plasmid DNA (pDNA) through complementary hydrogen bonding of guests with base pairs is reported. Poly(vinyldiaminotriazine) (PVDT) homopolymer and its copolymers with poly(1‐vinyl‐2‐pyrrolidone) are synthesized via conventional radical random polymerization, and water‐soluble fractions are collected. These PVDT‐based polymers efficiently complex pDNA and displace ethidium bromide (EB) in EB‐intercalated pDNA solutions because of the hydrogen‐bonding‐induced constrained state of pDNA. It is also found that upon complexation, pDNA seems to undergo B–C conformation change and circular dichroism spectra assumed a polymer‐and‐salt‐induced (psi)‐type pattern that is rationally ascribed to a certain change in the high‐order structure of DNA condensates. Transmission electron microscopy presented several morphologies of spheres and toroids within aggregates ≥ 100 nm, resembling DNA condensation induced by cationics. In transfection studies using pDNA‐encoding luciferase or enhanced green fluorescent protein, this system could efficiently transfect COS‐1 cells. Compared to the commercial polycation system, ExGen 500, these H‐bonding vectors display several merits such as higher transfection efficiency, lower cytotoxicity, better serum compatibility, and stability in the presence of bovine serum albumin (BSA). The results suggest that PVDT‐based polymers are superior to polycation counterparts with regard to their potential in vivo applications.
Hierarchical Porosity in Self‐Assembled Polymers: Post‐Modification of Block Copolymer–Phenolic Resin Complexes by Pyrolysis Allows the Control of Micro‐ and Mesoporosity
Authors: Valkama S. , Nykänen A. , Kosonen H. , Ramani R. , Tuomisto F. , Engelhardt P. , ten Brinke G. , Ikkala O. , Ruokolainen J. 
Published: December 2006

AbstractIt is shown that self‐assembled hierarchical porosity in organic polymers can be obtained in a facile manner based on pyrolyzed block‐copolymer–phenolic resin nanocomposites and that a given starting composition can be post‐modified in a wide range from monomodal mesoporous materials to hierarchical micro‐mesoporous materials with a high density of pores and large surface area per volume unit (up to 500–600 m2 g–1). For that purpose, self‐assembled cured composites are used where phenolic resin is templated by a diblock copolymer poly(4‐vinylpyridine)‐block‐polystyrene (P4VP‐b‐PS). Mild pyrolysis conditions lead only to monomodal mesoscale porosity, as essentially only the PS block is removed (length scale of tens of nanometers), whereas during more severe conditions under prolonged isothermal pyrolysis at 420 °C the P4VP chains within the phenolic matrix are also removed, leading to additional microporosity (sub‐nanometer length scale). The porosity is analyzed using transmission electron microscopy (TEM), small‐angle X‐ray scattering, electron microscopy tomography (3D‐TEM), positron annihilation lifetime spectroscopy (PALS), and surface‐area Brunauer–Emmett–Teller (BET) measurements. Furthermore, the relative amount of micro‐ and mesopores can be tuned in situ by post modification. As controlled pyrolysis leaves phenolic hydroxyl groups at the pore walls and the thermoset resin‐based materials can be easily molded into a desired shape, it is expected that such materials could be useful for sensors, separation materials, filters, and templates for catalysis.
Quantitative measurements of liquid holdup and drainage in foam using NMRI
Authors: Stevenson Paul , Mantle Michael D. , Sederman Andrew J. , Gladden Lynn F. 
Published: December 2006

AbstractLiquid fraction profiles of a column of draining aqueous foam stabilized with sodium dodecyl sulfate were studied by nuclear magnetic resonance imaging (NMRI) at high spatial and temporal resolution. It was observed that the liquid holdup in the column is not locally homogeneous in the direction of the column axis with liquid holdup exhibiting periodic variation in time. This creates “ripples” in the liquid content profiles (that is, an approximately sinusoidal variation of liquid fraction in space). These ripples are seen to actually rise in the column as liquid drains down through the foam. This behavior may be explained by a simple mass balance: the rising velocity of the ripples multiplied by the gas fraction in the foam is equivalent to the liquid superficial drainage rate. Thus, NMRI is proposed as a powerful tool for studying drainage of foams because it provides a noninvasive method of measuring superficial drainage rate in foams that yields time‐resolved instantaneous drainage rates as a function of position in the column. The measured liquid drainage rates were compared with a dimensionless expression for the liquid drainage rate and excellent agreement was achieved. © 2006 American Institute of Chemical Engineers AIChE J, 2007
Mitochondrial DNA variation within and among regional populations of longtail macaques (Macaca fascicularis) in relation to other species of the fascicularis group of macaques
Authors: Smith David Glenn , Mcdonough John W. , George Debra A. 
Published: December 2006

AbstractAn 835 base pair (bp) fragment of mitochondrial DNA (mtDNA) was sequenced to characterize genetic variation within and among 1,053 samples comprising five regional populations each of longtail macaques (Macaca fascicularis) and rhesus macaques (Macaca mulatta), and one sample each of Japanese (M. fuscata) and Taiwanese (M. cyclopis) macaques. The mtDNA haplotypes of longtail macaques clustered in two large highly structured clades (Fas1 and Fas2) of a neighbor‐joining tree that were reciprocally monophyletic with respect to those representing rhesus macaques, Japanese macaques, and Taiwanese macaques. Both clades exhibited haplotypes of Indonesian and Malaysian longtail macaques widely dispersed throughout them; however, longtail macaques from Indochina, Philippines, and Mauritius each clustered in a separate well‐defined clade together with one or a few Malaysian and/or Indonesian longtail macaques, suggesting origins on the Sunda shelf. Longtail macaques from Malaysia and Indonesia were far more genetically diverse, and those from Mauritius were far less diverse than any other population studied. Nucleotide diversity between mtDNA sequences of longtail macaques from different geographic regions is, in some cases, greater than that between Indian and Chinese rhesus macaques. Approximately equal amounts of genetic diversity are due to differences among animals in the same regional population, different regional populations, and different species. A greater proportion of genetic variance was explained by interspecies differences when Japanese and Taiwanese macaques were regarded as regional populations of rhesus macaques than when they were treated as separate species. Rhesus macaques from China were more closely related to both Taiwanese and Japanese macaques than to their own conspecifics from India. Am. J. Primatol. 69:1–17, 2007. © 2006 Wiley‐Liss, Inc.
Molecular analyses of the intestinal microbiota of chimpanzees in the wild and in captivity
Authors: Uenishi Gentaro , Fujita Shiho , Ohashi Gaku , Kato Akino , Yamauchi Shino , Matsuzawa Tetsuro , Ushida Kazunari 
Published: December 2006

AbstractLittle information is available regarding the intestinal bacteria of chimpanzees in the wild, due to the technical difficulties of studying intestinal bacteria in the field. In this study, molecular‐based bacterial analyses were performed to overcome this difficulty because polymerase chain reaction (PCR)‐based methods, such as temperature gradient gel electrophoresis (TGGE) and amplified ribosomal DNA restriction analysis (ARDRA), of the bacterial 16S rRNA gene can be applied to ethanol‐fixed fecal samples. The common presence of bacteria belonging to the Clostridium rRNA sub‐group XIVa, such as Ruminococcus obeum and Eubacterium sp., was indicated for Bossou wild chimpanzees by ARDRA. TGGE on partial 16S rDNA followed by hierarchical clustering analysis showed a systematic difference in the composition of intestinal microbiota between wild and captive chimpanzees. However, several TGGE bands commonly shared by wild and captured chimpanzees were excised, and their sequences were obtained. They were suggested to be the Clostridium leptum subgroup bacteria, Lactobacillus gasseri‐like bacterium, and Bifidobacterium pseudocatenulatum‐ or B. catenulatum‐like bacterium. These may be considered as common intestinal bacteria for chimpanzees, and may be transmitted vertically over generations. Am. J. Primatol. 69:1–10, 2007. © 2006 Wiley‐Liss, Inc.
Predicting the frequency of food‐related agonism in white‐faced capuchin monkeys (Cebus capucinus), using a novel focal‐tree method
Authors: Vogel E.R. , Janson C.H. 
Published: December 2006

AbstractFood abundance and distribution have played a central role in the conceptual theory of primate socioecology [Janson, Behaviour 105:53–76, 1988; Isbell, Behavioral Ecology 2:143–155, 1991; Sterck et al., Behavioral Ecology and Sociobiology 41:291–309, 1997; van Schaik, In: Standen V, Foley RA, editors, Comparative Socioecology. Oxford: Blackwell. p 195–218, 1989]. This theory predicts that agonistic (“contest”) competition should occur when food is distributed in discrete, defensible patches; in contrast, when food sources are distributed uniformly or randomly, non‐agonistic (“scramble”) competition is expected. Primatologists usually measure resource density and patchiness from a botanical perspective, ignoring the biology of the animal being studied. Such an approach may be irrelevant in terms of how animals view the dispersion of resources. Using a novel focal‐tree method that measures resource availability on a scale that is both spatially and temporally relevant to the animal under investigation, we take a cost‐benefit approach to predict the frequency of food‐related agonism in white‐faced capuchin monkeys (Cebus capucinus) from 11 ecological and social variables. We retained four variables in the regression model: two representing the opportunity for aggression (i.e., feeding bout length and the number of feeding adult females), and two representing opportunity costs (i.e., fruit abundance and the number of potential feeding sites in the focal tree). The results of this study indicate that the amount of food‐related aggression in white‐faced capuchins can be predicted by variables representing the costs and benefits of contesting a food resource. Am. J. Primatol. 69:533–550, 2007. © 2006 Wiley‐Liss, Inc.
Cortisol response and ovarian hormones in juvenile and cycling female Cebus monkeys: effect of stress and dexamethasone
Authors: Lahoz Monica M. , Nagle Carlos A. , Porta Margarita , Farinati Zulema , Manzur Teresita D. 
Published: December 2006

AbstractWe examined cortisol profiles in relation to ovarian hormones and their response to a repeated composite stressor with and without dexamethasone suppression. To evaluate the day‐to‐day changes in circulating cortisol relative to ovarian hormones, we subjected five adult female Cebus apella monkeys daily to restraint, sedation, transport to a neighboring room for femoral venipuncture, and return to the cage throughout the menstrual cycle. The cortisol response to the repeated stressor for blood collection, its relationship with the ovarian function, and the effects of dexamethasone were evaluated in six juveniles (18–24 months old) and five adult females in the luteal phase. Blood was sampled at time 0; then the monkeys received the vehicle and their blood was sampled again at 1, 2, 4, and 24 hr. This experiment was repeated 3 weeks later, with dexamethasone (i.m. 2 mg/Kg) injected instead of vehicle. Plasma aliquots were assayed for cortisol, progesterone, and estradiol. The results revealed that from middle infancy and throughout adulthood, hypercortisolism is the norm in female Cebus monkeys. The high cortisol values remained unchanged across the cycle despite the cyclic changes in estradiol and progesterone levels. Juvenile monkeys exhibited a higher cortisol response to stress than adults, and both juvenile and adult monkeys exhibited the typical suppression by dexamethasone. A rapid suppression of progesterone co‐occurred in parallel with cortisol after dexamethasone injection in juvenile monkeys, suggesting that most circulating progesterone originates in the adrenals. In contrast, adult females exhibited an overincrement of progesterone levels, in parallel with a rise in cortisol, in response to the stressor, and this effect was exacerbated by dexamethasone. The findings suggest that hypercortisolism is insufficient to disrupt ovarian development toward a normal cyclical function, and that ovarian steroids have no influence on day‐to‐day circulating cortisol levels. On the other hand, the overincrement of progesterone levels induced by stress and/or glucocorticoids during the early luteal phase is unlikely to interfere with the development of this phase and implantation in this monkey species. Am. J. Primatol. 69:551–561, 2007. © 2006 Wiley‐Liss, Inc.