bluuebunny/crossref_metadata_2025 huggingface dataset:
Clays
Authors: Murray Haydn H.
Published: December 2006

The article contains sections titled:

1.Introduction2.Structure and Composition of Clay Minerals3.Geology and Occurrence of Major Clay Deposits3.1.Kaolin3.2.Smectite3.3.Palygorskite and Sepiolite3.4.Miscellaneous Clays4.Mining and Processing4.1.Kaolin4.1.1.Dry Process4.1.2.Wet Process4.1.3.Combined Dry and Wet Processing4.1.4.Special Processes4.2.Smectite4.3.Palygorskite and Sepiolite5.Properties and Uses5.1.Kaolin5.1.1.Physical Properties5.1.2.Paper5.1.3.Paint5.1.4.Ceramics5.1.5.Rubber5.1.6.Plastics5.1.7.Ink5.1.8.Catalysts5.1.9.Fiberglass5.2.Smectite5.3.Palygorskite and Sepiolites6.Environmental Aspects7.Production and Consumption

Clays are important industrial minerals that are utilized around the world. The clay minerals and materials discussed here are kaolins, smectites, palygorskite and sepiolite, and miscellaneous or common clays. Kaolin is both a rock term and a group minerals name for kaolinite, dickite, nacrite, and halloysite. Bentonite is a rock term and the dominant minerals in bentonite are smectites, which is a group mineral name. Important minerals in the smectite group are sodium, calcium, magnesium, iron, and lithium montmorillonites. Miscellaneous or common clays include shales, mudstones, soil clays, lacustrine clays, glacial tills, and so on, which are used for making brick, tile, other structural clay products, and stoneware pottery. They are usually comprised of a mixture of clay and nonclay minerals, the most common of which are illite, chlorite, mixed‐layer clays, and quartz. The geology and location of clay deposits that are marketed regionally and worldwide are described. Structure, composition, and chemical and physical properties of the clay minerals are discussed. These control the many industrial applications of clay minerals and materials. Important applications are described. World production figures of the various clays are given as of 2004. A brief discussion on health‐related and environmental issues is included.
Glucose and Glucose‐Containing Syrups
Authors: Schenck Fred W.
Published: December 2006

The article contains sections titled:

1.

Introduction and History

2.

Properties of Glucose

2.1.

Structure

2.2.

Physical Properties

2.3.

Chemical Properties

3.

Raw Materials

4.

General Principles of Starch Hydrolysis

4.1.

Production and Properties of Acid Glucose Syrups

4.2.

Production and Properties of Acid ‐ Enzyme Glucose Syrups

4.3.

Production and Properties of Enzyme ‐ Enzyme Glucose Syrups

5.

Production of Solid Glucose

5.1

Production of Total sugars

5.2

Production of Pure Crystalline Products

6.

Glucose ‐ Fructose Syrups

6.1.

Properties

6.2.

Production

6.3.

High‐Fructose Syrups from Inulin

7.

Analysis

8.

Legal Aspects

9.

Storage and Transportation

10.

Uses

11.

Economic Aspects

12.

Physiological Properties and Toxicology of Glucose
Phosphorus Compounds, Organic
Authors: Svara Jürgen , Weferling Norbert , Hofmann Thomas
Published: December 2006

The article contains sections titled:1.Introduction2.Phosphines2.1.Properties2.2.Production2.2.1.Primary and Secondary Phosphines2.2.2.Tertiary Phosphines2.3.Uses3.Halophosphines3.1.Properties3.2.Production3.3.Uses4.Phosphonium Salts4.1.Properties4.2.Production4.3.Uses5.Phosphine Oxides and Sulfides5.1.Properties5.2.Production5.3.Uses6.Phosphonous Acid Derivatives6.1.Production6.2.Properties and Uses7.Phosphinic Acids and their Derivatives7.1.Properties7.2.Production7.3.Phosphinic Acids and Phosphinate Esters7.4.Thiophosphinates7.5.Other Phosphinic Acid Derivatives8.Phosphites and Hydrogenphosphonates8.1.Properties8.2.Production8.3.Trialkyl Phosphites8.4.Triaryl Phosphites and Alkyl Aryl Phosphites8.5.Dialkyl and Diaryl Phosphonates8.6.Alkyl Phosphonates9.Phosphonic Acids and their Derivatives9.1.Properties9.2.Production9.3.Phosphonic Acids and Phosphonocarboxylic Acids9.4.Esters of Phosphonic Acid9.5.Other Derivatives of Phosphonic Acid10.Esters of Phosphoric Acid10.1.Properties10.2.Production10.3.Trialkyl Phosphates10.4.Triaryl and Alkyl Aryl Phosphates10.5.Mono‐ and Dialkyl Phosphates11.Esters of Thiophosphoric Acid11.1.Properties11.2.Production11.3.Monothiophosphates11.4.Dithiophosphates12.Economic Aspects13.Toxicology
Photoelectricity
Authors: Lutz Manfred
Published: December 2006

The article contains sections titled:1.Introduction2.External Photoeffect3.Internal Photoeffect4.Applications4.1.Light Sensors and Detectors4.2.Solar Cells4.3.Imaging Systems

Photoelectricity is one of the key phenomena of today's imaging and communication technologies. In general, photoelectricity is understood as the interaction of photons with solids, resulting either in a liberation of electrons (external photoeffect) or in an enhanced electrical conductivity (internal photoeffect). Both effects are discussed particularly with regard to the basic principles and materials involved.

Photoelectricity with its link between light flux and electrical current was the basis for a huge technical and scientific effort directed to enhance, extend, and diversify devices in their functions as light sensors and detectors and later as image pick‐up systems which enable transmission, processing, display, and printout of the received optical information; e.g., solar cells and sensor arrays for digital still and video cameras.
Potassium and Potassium Alloys
Authors: Burkhardt Elizabeth R.
Published: December 2006

The 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.Acknowledgement

Potassium 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

The 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

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

The 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

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

The 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

A 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

It 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

Liquid 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

An 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

Little 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

Food 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

We 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.
Biodegradable polymers. XI. Spectral, thermal, morphological, and biodegradability properties of environment‐friendly green plastics of soy protein modified with thiosemicarbazide
Authors: Nanda Prativa K. , Krishna Rao K. , Nayak Padma L.
Published: December 2006

The demand for biodegradable polymers produced from renewable natural resources continues to grow as environmental concerns increase. Biodegradable plastics derived from agricultural feedstock are a new generation of materials capable of reducing the environmental impact in terms of energy consumption and greenhouse effect in specific applications to perform as traditional/conventional plastics when in use and are completely biodegradable within a composting cycle through the action of living/micro‐organisms. The objective of this study is to examine the potentiality and performance pattern of soy protein isolate (SPI) resin, modified with various concentrations of thiosemicarbazide (TSC), as a thermoplastic to substitute some conventional petroleum‐based plastics. The spectral, thermal, morphological properties and the biodegradability of the modified resin have been investigated. The spectral studies indicate that TSC is not crosslinked with the protein moiety; rather, it acts as a modifier. Thermogravimetric analysis of the modified material has been followed using a computer analysis method (LOTUS package) developed by us for assigning the degradation mechanism. A number of equations have been used to evaluate the kinetic parameters. The degradation mechanism has been ascertained on the basis of the kinetic parameters. It is expected that, this environment‐friendly, fully biodegradable and sustainable TSC‐modified SPI green plastic could be commercially used for making molded products. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3134–3142, 2007
Preparation and properties of magnetorheological elastomers based on silicon rubber/polystyrene blend matrix
Authors: Wang Yinling , Hu Yuan , Gong Xinglong , Jiang Wanquan , Zhang Peiqiang , Chen Zuyao
Published: December 2006

Magnetorheological (MR) elastomers, which are mainly composed of magnetic particles and elastic polymer, are a new kind of smart materials whose modulus can be controlled by changing the strength of magnetic fields. In this article, MR elastomers based on immiscible silicon rubber/polystyrene (SR/PS) blend matrix were fabricated successfully via cosolvent method and the MR effect, electric and mechanical properties, and the microstructures of the corresponding materials were studied. SEM studies showed that the dispersion of iron particles in blend matrix were different from that in single polymer, which could be further proved by the different electric conductivity. The MR effect of MR elastomers based on blend matrix varied with the different ratios of SR and PS, which was discussed in detail from the special dispersion of iron particles and of zero‐modulus of MR elastomers. In addition, the MR elastomers based on SR/PS blend matrix had enhanced mechanical properties, which made them more hopeful to be applied in practice. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3143–3149, 2007
Preparation and properties of cyanate ester modified by epoxy resin and phenolic resin
Authors: Lu Sheng‐Hua , Zhou Zhi‐Wei , Fang Li , Liang Guo‐Zheng , Wang Jie‐Liang
Published: December 2006

Stiff and brittle cyanate ester (CE) resin was modified by copolymerizing it with epoxy resin (ER) and phenolic resin (PR) to improve its toughness and flexibility. The cure process of the modified CE resin was characterized by gel time curves and differential scanning calorimetry curves. The Fourier transform infrared spectra of the modified CE resin showed its chemical structure during the curing process. The mechanical properties, thermal behavior, dielectric properties, and morphology of the modified CE resins were investigated. The results showed that an increase in epoxy and phenolic resins resulted in improved flexibility while maintaining thermal stability. When the mass ratio of CE/ER/PR was 70 : 15 : 15 (w/w), flexural strength and impact strength of the modified CE resin increased from 113.6 MPa and 5.2 kJ/m2 to 134.5 MPa and 16.7 kJ/m2, respectively. Little of the thermal stabilityand dielectric properties was sacrificed in the modification of the CE. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3150–3156, 2007
Synthesis of novel sulfonium salts and cationic polymerization of epoxides and vinyl ether
Authors: Hyun Dong Hun , Patil Prashant , Kim Jun Young , Kim Tae Ho
Published: December 2006

Novel 1‐methoxycarbonylethylmethylphenylsulfonium salts with nonnucleophilic anions, namely, hexafluorophosphate, hexafluoroantimonate, and tetrafluoroborate, were synthesized by the reaction of 1‐methoxycarbonylethylphenylsulfide and dimethyl sulfate followed by anion exchange with potassium hexafluorophosphate, sodium hexafluoroantimonate, and sodium tetrafluoroborate, respectively. The cationic polymerization (photopolymerization and thermal polymerization) of epoxy and vinyl ether monomers was carried out to demonstrate the applicability of the newly synthesized sulfonium salts. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3157–3163, 2007
Performance of concretes produced with superplasticizer
Authors: Kılınçkale F. M. , Doǧan G. G.
Published: December 2006

Nowadays, additive chemical substances are used in the production of high‐performance concrete composites. These additives increase the fresh workability of concrete by decreasing the water/cement (W/C) ratio. The aim of this study was to examine the effects of water‐soluble polymers on concrete performance. For this purpose concretes with and without additives were produced with W/C values of 0.52, 0.56, and 0.60. Chemical admixtures such as naphthalene formaldehyde sulfonate (N), melamine formaldehyde sulfonate (S), and a hyperplasticizers admixture (a special type of melamine sulfonated polymer) (H) were used in concrete. The amounts of these admixtures were at a ratio of 0.3, 0.5, and 1.0 wt % of the cement's weight. Experiments assessing slump, VeBe, percentage of air, and unit weight were done for comparison with the test results of the characteristics of fresh concrete with and without admixtures. The compressive strength of concretes was determined at 7, 28, and 56 days. The effects of chemical admixtures were studied by comparing the properties of fresh and hardened concrete samples with and without admixtures. When the W/C ratios were 0.56, 0.60, and H was 1 wt %, the biggest slump was obtained and found to be 22 cm. Concrete with a W/C ratio of 0.52 and H of 1% has the highest compressive strength. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3214–3219, 2007
Effects of nanoclay on the properties of cardanol‐modified‐resol‐epoxy‐novolac composite material
Authors: Nguyen Le Huong , Nguyen Dac Thanh , La Thai Ha , Phan Kim Xuyen , Nguyen Thi Thanh Thao , Nguyen Huu Nieu
Published: December 2006

A nanocomposite based on nanoclay and resol that was modified with cardanol, a natural alkyl phenol, shows improvement for the glass‐fiber‐reinforced epoxy‐composite system. Dispersion of the nanocomposite was investigated by X‐ray, showing good results obtained by the in situ polymerization method. The mechanical properties of the final composites were improved by doping a 6 wt% of nanoclay in cardanol‐modified‐resol (CMR) into the epoxy matrix. The results show that a 15 wt% of CMR in epoxy is a most suitable ratio. Using polyamide as a curing agent instead of other traditional systems, such as anhydrides or amines for epoxy resin, overcame important limitations, further allowing for improved processability. The overall composite performance was enhanced. Additionally, the thermal stability of the system was investigated by thermal gravimetric analysis. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3238–3242, 2007
Influence of the initiator system on the spatial inhomogeneity in acrylamide‐based hydrogels
Authors: Orakdogen Nermin , Okay Oguz
Published: December 2006

The effect of the initiator system used in the gel preparation on the spatial inhomogeneity in poly(acrylamide) (PAAm) and poly(N,N‐dimethylacrylamide) (PDMA) hydrogels was investigated by static light scattering and elasticity measurements. The hydrogels were prepared by free‐radical crosslinking copolymerization of the monomers acrylamide (AAm) or N,N‐dimethylacrylamide (DMA) with N,N′‐methylenebisacrylamide as a crosslinker. Two different redox‐initiator systems, ammonium persulfate (APS)–N,N,N′,N′‐tetramethylethylenediamine (TEMED) and APS–sodium metabisulfite (SPS), were used to initiate the gelation reactions. Compared to the APS–TEMED redox pair, no significant scattered light intensity rise was observed during the crosslinking polymerization reactions initiated by the APS–SPS system. It was found that both PAAm and PDMA gels are much more homogeneous when the APS–SPS redox pair was used as the initiator. The results are explained by the formation of shorter primary chains as well as the delay of the gel point in APS–SPS initiated gel formation reactions. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3228–3237, 2007
Macroporous chelating resins incorporating heterocyclic functional groups via hydrophilic PEG spacer arms. I. Synthesis and characterization
Authors: Ji Chunnuan , Qu Rongjun , Sun Changmei , Wang Chunhua , Xu Qiang , Sun Yanzhi , Li Chunxian , Guo Shuhua
Published: December 2006

A series of novel chelating resins were synthesized by incorporating heterocyclic functional groups such as 2‐aminopyridine (AP), 2‐amino‐5‐methylthio‐1,3,4‐thiadizole (AMTZ), 2‐amino‐5‐ethyl‐1,3,4‐thiadizole (AETZ), and 2‐mercaptobenzothiazole (MBZ) into macroporous crosslinked polystyrene via a hydrophilic spacer arm of polyethylene glycol containing sulfur. Structures of the above‐mentioned resins were characterized by elemental analysis, Fourier transform‐infrared spectra (FTIR), ASAP‐2020 surface area and porosity analyzer, and scanning electron microscopy (SEM). © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3220–3227, 2007
Synthesis and characterization of alkali‐modified styrene‐maleic anhydride copolymer for dispersion of TiO2
Authors: Kumari Suman , Nigam Dhirendra , Agarwal Devendra , Nigam Indira
Published: December 2006

A copolymer of styrene and maleic anhydride was synthesized by free radical polymerization at 80°C using N,N‐dimethylformamide (DMF) as solvent and benzoylperoxide as initiator. The monomer feed ratio of styrene to maleic anhydride was varied in the range of 1 : 1 : to 3 : 1. The polymer yield was found to decrease with increase in styrene in the feed. The molecular weight of copolymers which were formed by taking styrene to maleic anhydride ratio of 1 : 1, 2 : 1, and 3 : 1, as determined by Ostwald Viscometery were about 1862, 2015, and 2276 respectively. The acid values of abovementioned three copolymers were found to be 480, 357, and 295, respectively. The typical viscosity values of 20% solids in ammonical solution of copolymers formed by taking feed ratios of Sty : MAn as 1 : 1 and 2 : 1 were 26 and 136 cp, respectively. For the feed ratio 3 : 1, a gel was formed. The synthesized copolymers were hydrolyzed by alkalis, namely, NaOH, KOH, and NH4OH. The dispersing ability of hydrolyzed styrene‐maleic anhydride (SMA) copolymers for dispersion of titanium dioxide was studied. The modified SMA copolymers were found to be effective dispersants for TiO2. Among the three alkalis studied, the Sodium salts of SMA were found to give better dispersion. The copolymer having a 1 : 1 feed ratio showed the best dispersing ability for TiO2 particles among the three ratios studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3194–3205, 2007
Construction of a novel sensor based on electropolymerization of carmine for voltammetric determination of 4‐nitrophenol
Authors: Li Chunya
Published: December 2006

4‐Nitrophenol (4‐NP) has been determined with voltammetric technique based on a novel sensor fabricated by electropolymerization of carmine on a glassy carbon electrode (GCE). An obvious reduction peak located at about −0.700 V and a couple of redox peaks that were not well‐defined were observed in the potential range of −1.00 to 0.600 V. Compared with its voltammetric behavior on a bare GCE, the reduction peak potential shifted positively and the peak current increased significantly. All experimental parameters were optimized and linear sweep voltammetry was proposed for its determination. In the optimal conditions, the reduction peak current was proportional to the 4‐NP concentration over the concentration range from 5.00 × 10−8 to 1.00 × 10−5 mol L−1, and the detection limit was 1.00 × 10−8 mol L−1 after 200 s of accumulation. The high sensitivity and selectivity of the sensor was demonstrated by its practical application for the determination of trace amounts of 4‐NP in lake water. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3271–3277, 2007
Master curve and time–temperature–transformation cure diagram of lignin–phenolic and phenolic resol resins
Authors: Alonso M. V. , Oliet M. , García J. , Rodríguez F. , Echeverría J.
Published: December 2006

The aim of this work is to generate both a master curve of resol resins based on the time–temperature superposition principle and their TTT cure diagrams. The samples used for this purpose were lignin–phenolic and phenol–formaldehyde resol resins. A TMA technique was employed to study the gelation of resol resins. In addition, a DSC technique was employed to determine the kinetic parameters through the Ozawa method, which allowed us to obtain isoconversional curves from the data fit to the Arrhenius expression. Establishing the relationship between the glass‐transition temperature and curing degree allowed the determination of the vitrification lines of the resol resins. Thus, using the experimental data obtained by TMA and DSC, we generated a TTT cure diagram for each of resins studied. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3362–3369, 2007
Isothermal crystallization kinetics in binary miscible blend of poly(ε‐caprolactone)/tetramethyl polycarbonate
Authors: Madbouly Samy A.
Published: December 2006

The crystallization kinetics of pure poly(ε‐caprolactone) (PCL) and its blends with bisphenol‐A tetramethyl polycarbonate (TMPC) was investigated isothermally as a function of composition and crystallization temperature (Tc) using differential scanning calorimetric (DSC) and polarized optical microscope techniques. Only a single glass‐transition temperature, Tg, was determined for each mixture indicating that this binary blend is miscible over the entire range of composition. The composition dependence of the Tg for this blend was well described by Gordon–Taylor equation with k = 1.8 (higher than unity) indicating strong intermolecular interaction between the two polymer components. The presence of a high Tg amorphous component (TMPC) had a strong influence on the crystallization kinetics of PCL in the blends. A substantial decrease in the crystallization kinetics was observed as the concentration of TMPC rose in the blends. The crystallization half‐time t0.5 increased monotonically with the crystallization temperature for all composition. At any crystallization temperature (Tc) the t0.5 of the blends are longer than the corresponding value for pure PCL. This behavior was attributed to the favorable thermodynamics interaction between PCL and TMPC which in turn led to a depression in the equilibrium melting point along with a simultaneous retardation in the crystallization of PC. The isothermal crystallization kinetics was analyzed on the basis of the Avrami equation. Linear behavior was held true for the augmentation of the radii of spherulites with time for all mixtures, regardless of the blend composition. However, the spherulites growth rate decreased exponentially with increasing the concentration of TMPC in the blends. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 103: 3307–3315, 2007
Reduction in orofacial clefts following folic acid fortification of the U.S. grain supply
Authors: Yazdy Mahsa M. , Honein Margaret A. , Xing Jian
Published: December 2006

BACKGROUND:

Folic acid fortification in the United States became mandatory January 1, 1998, to reduce the occurrence of neural tube defects (NTDs). We evaluated the impact of folic acid fortification on orofacial clefts using United States birth certificate data for 45 states and the District of Columbia.

METHODS:

Prevalence ratios (PRs) were calculated comparing orofacial cleft prevalence among births prefortification (1/1990–12/1996) and postfortification (10/1998–12/2002), based on fortification status at conception. The JoinPoint Regression Program and exponentially weighted moving average charts (EWMA) were used to assess the timing of any statistically significant changes in prevalence. Data were stratified by maternal race/ethnicity, age, smoking, and timing of prenatal care.

RESULTS:

Orofacial clefts declined following folic acid fortification (PR = 0.94; 95% CI: 0.92–0.96). The EWMA chart flagged a significant decrease in the fourth quarter of 1998. The JoinPoint graph had one change in slope, with a significant quarterly percent change (−0.34) between 1996 and 2002. The decline in orofacial clefts occurred in non‐Hispanic Whites but not other racial/ethnic groups, nonsmokers but not women who reported smoking during pregnancy, and women who received prenatal care in the first trimester but not women who began receiving care later in pregnancy.

CONCLUSION:

Folic acid fortification in the United States was associated with a small decrease in orofacial cleft prevalence, with the timing of the decline consistent with the introduction of fortification. The decline is much smaller than that observed for NTDs, but nonetheless suggests an additional benefit of this public health intervention. Birth Defects Research (Part A) © 2006 Wiley‐Liss, Inc.