bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of Surface Breaking Cracks in Concrete Members Using Rayleigh Waves
Authors: Zerwer A. , Polak M. A. , Santamarina J. C.
Published: November 2006

This study examines the use of Rayleigh waves for the detection and sizing of surface-breaking cracks in concrete members. First, finite element simulations are performed to define the conditions for Rayleigh wave propagation in members with rectangular cross-section followed by an experimental study with a concrete beam. Time histories recorded at different locations are 2D Fourier transformed into the frequency-wavenumber domain to enhance interpretation and data analysis. Rayleigh waves form at depths less than half the beam depth. With the introduction of a slot, Rayleigh waves are not observed behind the slot, except for the shortest slot depth, and the slot depth cannot be estimated in the frequency-wavenumber domain. Autospectrum calculations reveal strong Rayleigh wave reflections in front of the slot and by can be used to estimate slot depth when the wavelength is less than half the beam depth.
The Application of an Airborne Electromagnetic System in Groundwater Resource and Salinization Studies in Jilin, China
Authors: Meng Qingmin , Hu Hui , Yu Qinfan
Published: November 2006

Airborne electromagnetic (AEM) systems were first developed in the early 1950’s in Canada and Scandinavia. AEM systems have been applied in mineral exploration, geological mapping, geohydrological investigation and environmental monitoring in China since the 1980’s. A dual-frequency AEM system ([Formula: see text], [Formula: see text]) which was developed by IGGE in the early 1980’s has surveyed more than [Formula: see text]. A new three-frequency AEM system was also developed by IGGE in 1999. In 2001, a survey was conducted in Qian’an, Jilin Province, using the new AEM system. The purpose of this survey was to delineate salinization, to determine the freshwater∕saltwater interface and to explore the freshwater resource for catchment management such as drinking, agriculture, stock raising and wetland protection. The main purpose was achieved by this survey. For the salinization study, the upper frequency AEM data were used. By comparing the apparent resistivities calculated from the AEM data with the geohydrological data, the areas and intensity of salinization were identified. For the freshwater resource study, lower and middle frequency AEM data were applied. Two zones of fresh ground-water were determined within the achievable exploration depth (about [Formula: see text]) of the AEM system.
Geophone Coupling Match and Attenuation Compensation in Near-Surface Seismic Exploration
Authors: Tian Gang , Shi Zhanjie , Dong Shixue , Wang Zhejiang
Published: November 2006

An effective geophone-to-ground couple is often difficult to achieve in loose sediment. Unconsolidated sediment can significantly attenuate the high-frequency component of seismic data. Consequently, the resolution and signal-to-noise (S∕N) ratio of seismic data are adversely affected. In order to minimize these effects, two approaches for enhancing seismic reflection data on the basis of ancillary measurements are demonstrated. A coupling match filter was derived by using single trace seismic data from a Seismic Wave Detect System (SWDS) and common receivers under equivalent conditions. The filter was applied to convert a common shot gather to a SWDS shot gather. The high-frequency loss components in stacked data were corrected by an attenuation compensatory inverse filter constructed from uphole seismic data. The results show that the resolution of seismic data from the coupling match filter is nearly equivalent to that of the SWDS data. In addition, the resolution and S∕N ratio were enhanced by the compensatory attenuation inverse filter. These filters can be applied separately or in combination to improve the data quality and compensate high frequency loss in the seismic data without significantly affecting low frequency content.
Simulations of Seismic Wave Propagation and Ground Motion Acceleration in a Basin-like Structure
Authors: Zhao Zhixin , Xu Jiren
Published: November 2006

In this analysis, seismic wave propagation and ground motion acceleration in heterogeneous media are digitally simulated for both line and plane sources by using the pseudospectral method of staggered grid RFFT differentiation in order to show the complicated characteristics of ground motion distribution in a basin-like structure. We are particularly concerned with those frequencies that can cause damage to dams or buildings within the basin-like structure. The results show that the distribution of strong motion varies greatly with geological structure. The seismic energy transmitted into a sediment-filled basin-like structure from the bedrock may not reflect and refract back into the rock region under the bottom of the basin structure. The seismic energy is absorbed by the sediment and soil layers, and converted into the energy of the oscillations of the medium, with large amplitudes within the basin-like structures. The seismic wave propagating up and down within the basin structure may result in major damage to buildings and dams, both internal and external to the basin. It is perhaps the most notable characteristic of this modeling research. Interference occurring near the basin results in peak ground motions and high collapse ratios of buildings away from the earthquake fault. The interference strongly affects the distribution of maximum amplitudes of seismic waveforms in and around the basin structure. In addition to active fault and geological structural surveying, the simulation analyses suggest that a geophysical survey, including mapping the seismic velocity structure in the medium above the bedrock, is the most important task for aseismic studies and disaster mitigation. This study also demonstrates a need for shallow geophysics to image shallow structure in earthquake-prone areas.
Application of EM Methods for the Investigation of Qiyueshan Tunnel, China
Authors: He Lanfang , Feng Minghai , He Zhanxiang , Wang Xuben
Published: November 2006

A successful case history of applying the high-frequency passive source electromagnetic (EM) method and controlled-source audiomagnetotellurics (CSAMT) to investigate the Qiyueshan (Q) Tunnel route is presented in this paper. The high-frequency EM system (EH-4, with frequency range from [Formula: see text]) and the CSAMT system (V6-A Multipurpose Receiver, with frequency range from [Formula: see text]) were used for the data acquisition. The orthogonal components of the electromagnetic field were measured in the high frequency EM method, while scalar measurements of the electrical and magnetic field components were used in the CSAMT method. The relevant electrical properties of the earth were extracted from the electromagnetic profiles. High frequency EM has high resolution in the shallow earth but a smaller depth of exploration, while the CSAMT method has a powerful signal but a lower resolution in the shallow earth. The integration of the two methods might be effective for the survey of the deep tunnel route. Q Tunnel, located in central south China, has a length of [Formula: see text] and a depth of up to [Formula: see text]. Half of the tunnel goes through karst terrain, where the geologic structures are very complex, due to cavities, underground rivers and faults. The EM mapping results distinguish the electrical resistivity of different rock formations. Five low-resistivity areas and four high-resistivity areas were found and nine faults were verified by the EM method. These findings were very useful for the later engineering design.
Crosshole Radar Tomography in a Fluvial Aquifer near Boise, Idaho
Authors: Clement William P. , Barrash Warren
Published: November 2006

To determine the distribution of heterogeneities in the saturated zone of an unconfined aquifer in Boise, ID, we compute tomograms for three adjacent well pairs. The fluvial deposits consist of unconsolidated cobbles and sands. We used a curved-ray, finite-difference approximation to the eikonal equation to generate the forward model. The inversion uses a linearized, iterative scheme to determine the slowness distribution from the first arrival traveltimes. The tomograms consist of a layered zone representing the saturated aquifer. The velocities in this saturated zone range between [Formula: see text]. We use a variety of methods to assess the reliability of our velocity models. Finally, we compare our results to neutron-derived porosity logs in the wells used for the tomograms. The comparison shows that the trends in porosity derived from the tomograms match the trends in porosity measured with the neutron probe.
Water and terrorism
Authors: Gleick Peter H.
Published: November 2006

The importance of freshwater and water infrastructure to human and ecosystem health and to the smooth functioning of a commercial and industrial economy makes water and water systems targets for terrorism. The chance that terrorists will strike at water systems is real; indeed, there is a long history of such attacks. Water infrastructure can be targeted directly or water can be contaminated through the introduction of poison or disease-causing agents. The damage is done by hurting people, rendering water unusable, or destroying purification and supply infrastructure. More uncertain, however, is how significant such threats are today, compared with other targets that may be subject to terrorist attack, or how effective such attacks would actually be. Analysis and historical evidence suggest that massive casualties from attacking water systems are difficult to produce, although there may be some significant exceptions. At the same time, the risk of societal disruptions, disarray, and even overreaction on the part of governments and the public from any attack, may be high. This paper reviews the history of past attacks on water systems and the most pressing vulnerabilities and risks facing modern water systems. Suggestions of ways to reduce those risks are also presented.
Obstruction of the small intestine by a trichobezoar in cattle: 15 cases (1992–2002)
Authors: Abutarbush Sameeh M. , Naylor Jonathan M.
Published: November 2006

Objective—To determine historical and clinical findings, treatment, and outcome for cattle with small intestinal obstruction caused by a trichobezoar.

Design—Retrospective case series.

Animals—15 cattle.

Procedures—Medical records of cattle with a diagnosis of small intestinal obstruction by a trichobezoar from 1992 to 2002 were reviewed. Information pertaining to various aspects of diagnosis, treatment, and outcome was collected from records.

Results—Trichobezoars were more common in young cattle, and affected cattle did not deteriorate clinically as rapidly as cattle with other types of intestinal obstruction. The most common initial owner complaints included decreased or absent fecal output, inappetance, abdominal distension, and signs of abdominal pain. Common clinical findings were dehydration, decreased or absent rumen motility, signs of depression, splashing sounds during succussion of the abdomen, and a pinging sound on percussion of the abdomen. The jejunum was obstructed in 10 cattle. Hypochloremic metabolic alkalosis and chronic inflammation were common laboratory findings. All 4 cattle that underwent abdominocentesis had peritonitis. The obstructing trichobezoar was removed surgically in 9 cattle, of which 7 survived and 2 died. The 6 cattle treated medically died or were euthanized.

Conclusions and Clinical Relevance—Obstruction of the small intestine by a trichobezoar is uncommon, but it should be considered as a differential diagnosis in cattle with signs of intestinal obstruction, particularly if they are younger than 4 years of age and have a history of nonacute signs of intestinal obstruction. Surgical removal appears to be a favorable method of treatment and should be considered when this condition is suspected.
Fabrication of nanostructure via self-assembly of nanowires within the AAO template
Authors: Wang Zhen , Brust Mathias
Published: November 2006

The novel nanostructures are fabricated by the spatial chemical modification of nanowires within the anodic aluminum oxide (AAO) template. To make the nanowires better dispersion in the aqueous solution, the copper is first deposited to fill the dendrite structure at the bottom of template. During the process of self-assembly, the dithiol compound was used as the connector between the nanowires and nanoparticles by a self-assembly method. The nanostructures of the nano cigars and structure which is containing particles junction are characterized by transmission electron microscopy (TEM). These kinds of novel nanostructure will be the building blocks for nanoelectronic and nanophotonic devices.
5‐Hydroxy fatty acid amides from δ‐lactones and alkyl glucamines
Authors: Frykman Hans B. , Isbell Terry , Cermak Steven C.
Published: November 2006

δ‐Lactones derived from unsaturated fatty acids are useful precursors to fatty amides due to their enhanced reactivity. Consequently, temperature‐sensitive glucamines were easily converted to their 5‐hydroxy fatty acid amides in high yield (52–97%) by reaction with C18 and C20 δ‐lactones. High yields of amides (52–97%) were obtained with little or no solvent at 90°C in less than 24 h. C18 δ‐lactones were more miscible in the glucamine than the C20 δ‐lactones and thus increased reaction rates and yields of amides. In addition, amidation reactions run in the absence of catalyst gave good yields, whereas reactions in the presence of base catalysts completely inhibited the reaction. The 1‐(N‐alkyl‐5‐hydroxy fatty acid amido)‐d‐glucitols are expected to have useful properties as biodegradable components in detergents.
Combined monte carlo/thermodynamic model of formation of microporous aggregate structure like silica from quaternary ammonium silicate solutions
Authors: Romm Freddy , Karchevsky Valeria , Figovsky Oleg
Published: November 2006

Quaternary ammonium silicate is a surfactant with very high content of silica that allows its use for preparation of protective coatings. The problem of silica aggregation from quaternary ammonium solution in limited volume is the focus of this paper. The system is described by a model based on a Monte Carbo approach with thermodynamic limitations. Thermodynamic characteristics are estimated by statistical polymer method. The model is employed for estimation of such properties as monomer concentration and tortuosity. The results of computer simulation are used for forecasting properties of coatings and for practical preparation of samples coated with quaternary ammonium silicate‐based composition.
Hydrophobic hydration of cationic mixed micelles by alkoxyethanols in aqueous media
Authors: Singh Bakshi Mandeep , Doe Hidekazu
Published: November 2006

The conductances of hexadecylpyridinium chloride (HPyCl) + tetradecyltrimethylammonium bromide (TTAB) mixtures over the entire mole fraction range of HPyCl (αHPyCl) were measured in aqueous binary mixtures of ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, and diethylene glycol monobutyl ether containing 10 to 30 wt% additive in their respective binary mixtures at 30°C. Each conductivity curve showed a single break over the whole mole fraction range of HPyCl + TTAB mixtures. From the break in the conductivity curve, various micellar parameters were calculated and the results were discussed on the basis of alkoxyethanol's hydrophobic hydration of the mixed micelle. The micellar parameters of HPyCl, TTAB, and of their mixtures showed a strong dependence both on the amount and on the number of repeating units of ethylene and diethylene glycol derivatives. The hydrophobic hydration was considerably higher in the case of diethylene glycol derivatives owing to the presence of an extra ether oxygen. An evaluation of the non‐ideality in the HPyCl + TTAB mixtures in the presence of additives revealed that alkoxyethanols reduce the unlike surfactant monomer interactions in order to form the mixed micelles in comparison to those in pure water. It has also been observed that such interactions systematically decrease with an increase in the number of repeating units from monomethyl ether to monobutyl ether, both in the case of ethylene and diethylene glycol derivatives.
Analysis of surfactants: Part II
Authors: Morelli John J. , Szajer Gerald
Published: November 2006

We present a comprehensive review of the literature devoted to the analysis of surfactants. The period covered is 1995 through 1998. We address patents, reviews, books, journal articles, and any conference proceedings abstracted by Chemical Abstract Services. We consider classical, instrumental, and state‐of‐the‐art analytical applications, including those not in common practice but in a developmental stage. We also include analytical techniques that make use of surfactants for improved performance, although such treatment is not comprehensive. Literature from foreign language sources is covered as completely as practical.
High‐performance poly(butylene oxide)/poly (ethylene oxide) block copolymer surfactants for the preparation of water‐in‐oil high internal phase emulsions
Authors: Mork Steven W. , Rose Gene D. , Green D. Patrick
Published: November 2006

High‐performance surfactants have been developed for the preparation of water‐in‐oil high internal phase emulsions (HIPE), particularly for the preparation of polymerized HIPE foams. High‐efficiency surfactants with poly(butylene oxide)/poly(ethylene oxide) (BO/EO) block copolymer backbones have been developed that can stabilize an HIPE through polymerization at concentrations as low as 0.006 wt% based on total emulsion weight. Polymerizable versions have been developed that bind into the polymeric foam backbone. BO/EO block copolymer surfactants also allow preparation of polymerized HIPE foams without salt in the aqueous phase. HIPE with the BO/EO surfactants have been prepared at room temperature and polymerized at temperatures exceeding 90°C. By minimizing the required amount of surfactant, allowing the surfactant to react during HIPE polymerizations, eliminating the need for salt, and stabilizing over a broad range of temperatures, BO/EO block copolymer surfactants have demonstrated their place as high‐performance HIPE surfactants.
A perspective on the contribution of surfactants and lipids toward “Green Chemistry”: Present states and future potential
Authors: Urata Kouichi , Takaishi Naotake
Published: November 2006

“Green Chemistry” has become a subject of increasing interest in recent years. The goal of efforts in this area is to develop environmentally friendly methods and processes to replace traditional reactions that use organic solvents, consume much energy, and generate undesirable by‐products and/or waste. Utilization of renewable resources is an important component of Green Chemistry. Fats and oils represent one such resource. They can give rise to many types of surfactants and lipids that can modify properties of boundary phases between different phases. Thus, phase‐transfer catalysts (PTC) based on surfactants or lipids have been reported to be useful in reactions such as oxidation and hydration reactions and in glycidyl ether formation. Another approach to satisfying Green Chemistry requirements is the recovery and recycling of reactants and/or substrates used. In the preparation of alkyl glyceryl ethers, the intermediate 1,3‐dioxolane compounds prepared by addition of acetone to alkyl glycidyl ethers can be hydrolyzed to regenerate reusable acetone. Other examples of methodologies based on surfactants or lipids are summarized, and their potential contribution to Green Chemistry is discussed.
Contact angle of surfactant solutions on precipitated surfactant surfaces
Authors: Luangpirom Natthakeeraya , Dechabumphen Nimit , Saiwan Chintana , Scamehorn John F.
Published: November 2006

In this study, the contact angle of a saturated aqueous surfactant solution onto the surface of a precipitate of that surfactant is investigated. Those precipitates include fatty acids (C10, C12, C14, C16, and C18), sodium salts of fatty acids (C14, C16, and C18), calcium salts of fatty acids (C8, C10, C12, C14, C16, and C18). On virgin surfaces, free fatty acids and calcium salts of fatty acids have advancing contact angles (θA) between 77 and 92°, with little dependence on alkyl chain length for C12 and higher alkyl chains. The sodium salt of a fatty acid has a lower θA than the free fatty or the calcium salt of the soap. The calcium salt of dodecyl sulfate has a lower θA than the calcium salt of dodecanoic acid (θA = 46 vs. 82°), but the calcium salt of the 18‐carbon hydrophobes showed nearly the same contact angle for the soap and the alkyl sulfate. Greasiness, or slipperyness, or a scummy feel of a precipitated surfactant does not necessarily correspond to a hydrophobic surface.
Synthesis and surfactant properties of a new “extended” glucidoamphiphile made from D‐glucose
Authors: Scorzza C. , Godé P. , Martin P. , Miñana‐Pérez M. , Salager J. L. , Villa P. , Goethals G.
Published: November 2006

We prepared a new nonionic surfactant, 8, in which the n‐dodecyl chain is attached at the C‐3 carbon of the D‐glucose‐based glucopyranose moiety by the linkage Z=−O‐(α‐PP‐O)n with −O‐(α‐PP‐O)n being a commercial poly‐(α‐propyloxy) oligomeric mixture (with average ñ=6). This amphiphilic behavior study showed that, when compared to the reference compound 3‐O‐dodecyl‐D‐glucopyranose (Z=O), compound 8 exhibits (i) a water solubility that is 100‐fold higher, (ii) a hydrophilic‐lipophilic balance value increase from 8.5 to 12.6 units, and (iii) a slighly lower critical micelle concentration.
An alternative synthesis and mobile phase ion chromatography of alkanedisulfates
Authors: Cormier James F. , Dower Andrea , Boucher Sheryl , Blair Shamus , Marangoni D. Gerrard , Smith‐Palmer Truis
Published: November 2006

Preparation of alkane disulfates using chlorosulfonic acid results in a crude product containing significant amounts of chloride, sulfate, and hydroxyalkanesulfates. This paper describes an alternative synthesis using trimethylamine:sulfur dioxide complex in anhydrous pyridine. Workup with sodium hydroxide and washing in acetone results in a crude product with less than 1% inorganic impurity and ∼0–3% hydroxyalkanesulfate. Recrystallization from acetone reduces the inorganic impurity to less than 0.1%. Alkanedisulfates can be separated from the corresponding hydroxyalkanesulfates, chloride, and sulfate using mobile phase ion chromatography with tetrabutylammonium hydroxide (TBAOH) as the ion‐pairing agent and acetonitrile as the organic modifier. With the crude octanedisulfate and decanedisulfate product mixes, the alkanedisulfate is retained more strongly by the ion‐pairing effect; but with the tetradecane species, hydrophobic interaction dominates and the tetradecanedisulfate elutes before the hydroxytetradecanesulfate. The choice of acetonitrile gradient and TBAOH is particularly important for the separation of the dodecane derivatives because the opposing effects of polarity (hydrophobic effect) and electrostatic interaction with TBAOH are of similar strength.
Mixed monolayer and mixed micelle formation in binary mixture of surfactants—Systems for trioxyethylenated dodecyl sulfonate and some polyoxyethylenated fatty alcohol ether nonionic surfactants
Authors: Wang Zhong‐Ni , Li Gan‐Zuo , Mu Jian‐Hai , Zhang Wen‐Xia
Published: November 2006

The interaction and synergism of some polyoxyethylenated fatty alcohol ether (POE) nonionic surfactants (C12E2, C12E3, C10E5, C10E7, where Cx indicates number of carbon atoms in the chain and Ey indicates number of oxyethylene glycol ethers) with trioxyethylenated dodecyl sulfonate (C12E3S) in mixed monolayer formation at the surface and in mixed micelle formation in aqueous solutions were studied at 25 and 40°C by calculating interaction parameters (βα, βM) from surface tension‐concentration data by use of Rosen's equations based on the nonideal solution theory. All the systems investigated adapt reasonably well to the nonideal model, with negative values of βσ and βM (where M means micelle and σ refers to the air‐liquid interface) indicating a favorable interaction between the mixed surfactants. Either at a monolayer or in a mixed micelle, the attractive interaction becomes stronger when the alkyl chain in the POE surfactant is longer, i.e., when the POE becomes more hydrophobic. The interaction increases in the order C10E7<C10E5<C12E3, C12E2. For the two C10En (n= 5,7)/C12E3S systems, as temperature increases from 25 to 40°C, the interaction increases in a mixed micelle, but it decreases in a mixed monolayer. Synergism in mixed micelle formation exists for C12E3S/C10En mixtures when X1M, the mole fraction of POE in a mixed micelle, is ≈0.4–0.8, whereas synergism does not occur in the systems of C12E3S/C12Em due to the large difference between CMC1 and CMC2, i.e., large |In(C1M/C2M)| value (where CMC=critical micelle concentration). The degree of synergism in mixed micelle formation is temperature independent and is 0.23, 0.18, and close to zero for C10E5/C12E3S, C10E7/C12E3S, and C12Em(m=2,3)/C12E3S systems, respectively. Synergism in surface tension reduction effectiveness occurs in C12E3S/C12E2 and C12E3S/C12E3 systems. The mole fractions of POE in the solution phase are 0.302 and 0.333 for the two mixtures at the point of maximum synergism.
Self‐assembly of compounds based on a glycerin skeleton as C‐3 building block. Part II
Authors: Urata Kouichi , Takaishi Naotake
Published: November 2006

Part I reviewed the properties of alkyl glyceryl ethers and their derivatives in forming self‐assemblies such as liquid crystals. Part II covers strategies for the synthesis of several types of artificial ether lipids with a glycerin backbone, such as dicephalic surfactants, gemini surfactants, calamitic bola‐amphiphiles, dendrimers, and membrane components of archaebacteria, which have been reported to constitute unique self‐assemblies useful as materials for future nanochemistry.
Synthesis and study of the surface properties of long‐chain alkylnaphthalene sulfonates
Authors: Tan Xiaoli , Zhang Lu , Zhao Sui , Yu Jiayong , An Jingyi
Published: November 2006

Long‐chain alkylnaphthalene sulfonates were synthesized by means of a Wurtz‐Fittig reaction, and the basic properties were studied in water at 30°C. Through surface tension measurements, the following values were determined: the critical micelle concentration (CMC) and the surface tension at the CMC (γCMC). The following values were calculated: area per molecule at the CMC (ACMC), standard free energy change of micellization (ΔGmico), standard free energy of adsorption (ΔGado), and the “efficiency” of a surfactant in reducing surface tension (pC20). The micelle aggregation numbers were measured through steady‐state fluorescence‐quenching methods. As the chain length of the hydrocarbon of n‐alkylnaphthalene sulfonate increased, the Krafft temperature increased, the surface tension decreased, the value of CMC decreased, pC20 increased, ΔGado and ΔGmico became more negative, and the micelle aggregation number increased. The results showed that sodium α‐(n‐decyl)naphthalene sulfonate (DNS) had a high pC20, low Krafft temperature, and lower CMC than other surfactants in this study. Thus, DNS and the other n‐alkylnaphthalene surfactants studied exhibit desirable properties that may be of value in some fields such as detergency, oil recovery, and dyes.
Characterization of alcohol ethoxylates as alcohol ethoxy sulfate derivatives by liquid chromatography‐Mass spectrometry
Authors: Cassani Giorgio , Pratesi Claudio , Faccetti Lorella , Pravettoni Stefano , Nucci Giancarlo , Andriollo Nunzio , Valtorta Luigi , Matheson Lee
Published: November 2006

The characterization of alcohol ethoxylates (AE) to determine ethylene oxide (EO) adduct distribution has been studied in our laboratory for many years by using high‐performance liquid chromatography‐mass spectrometry (LC‐MS). This paper describes the LC‐MS approach being used to analyze both nonderivatized and derivatized AE. We conclude that the best way to determine EO adduct distribution is by first converting the AE to alcohol ethoxy sulfates (AES) and then by using LC‐MS with electrospray ionization in the negative ion mode. A convenient laboratory technique for converting small‐scale samples of AE to AES has been discovered and is reported herein. Several examples of EO adduct distribution determined by this method are presented for both linear and isomeric AE samples.
Synthesis and evaluation of new amphiphilic polyethylene glycol‐based triblock copolymer surfactants
Authors: Mohamed M. Z. , Ismail D. A. , Mohamed A. S.
Published: November 2006

We report in this investigation the synthesis of a new series of amphiphilic ABA‐triblock copolymers consisting of double‐chain hydrophobic moieties (A) of different chain lengths attached to each end of polyethylene glycols of different molecular weights (B). The identities of the prepared compounds were confirmed by elemental and Fourier transform infrared analyses. The prepared compounds showed good water solubility. Some of their surface properties, such as the critical micelle concentration, effectiveness of water surface tension reduction, surface excess concentration, standard free energies of adsorption and micellization, and surface area per molecule, were determined.
Monitoring the linear alkylbenzene sulfonation process using high‐temperature gas chromatography
Authors: Molever K.
Published: November 2006

Controlling the linear alkylbenzene sulfonate (LAS) sulfonation process is a critical part of the LAS manufacturing process; this process can be monitored by assaying for LAS content, unsulfonated linear alkylbenzene (LAB), and LAB sulfones. Traditionally, assaying the LAB and LAB sulfone contents has been time consuming and not straightforward. A simple and rapid procedure is described for the isolation and simultaneous capillary gas chromatographic (GC) quantification of LAB and LAB sulfones in LAS. The procedure involves extraction of the unsulfonated LAB and the LAB sulfones into n‐heptane; sodium linear alkylbenzenesulfonate or linear alkylbenzenesulfonic acid (reacted to form sodium linear alkylbenzenesulfonate) remains in the aqueous extraction solvent layer. High‐temperature capillary GC using a specialty metal capillary column enables both LAB and high molecular weight LAB sulfones to be quantified.
Phase behavior of fatty acid/oil/water systems: Effect of the alkyl length chain acid
Authors: Bravo B. , Márquez N. , Ysambertt F. , Chávez G. , Cáceres A. , Bauza R. , Graciaa A. , Lachaise J. , Salager J. L.
Published: November 2006

The phase behavior of different fatty acids (FA) in pseudo‐ternary mixtures [(water)/(FA) + (alcohol)/(oil)] was studied. The Winsor I‐III‐II transitions of ionized compounds were attained by varying the FA composition through the formulation scan. The middle‐phase volume, the pH of the optimum system, and the partition coefficient increased with the chain length of FA. Conversely, the acid partition coefficient allows calculation of the Gibbs free energy of transfer of a CH2 group from oil to water, which is found to be +0.87 J/mol.
Quick identification of polyterephthalate in laundry detergents by simultaneous pyrolysis methylation‐gas chromatography/mass spectrometry
Authors: Uchiyama Toshihiko , Kawauchi Akihiko
Published: November 2006

This report summarizes method development for the identification of polyterephthalates using simultaneous pyrolysis methylation‐gas chromatography with mass spectrometry. Ground detergent products are directly pyrolyzed together with the methylation reagent tetramethylammonium hydroxide. Key fragments separated via gas chromatography are detected by a mass selective detector. Trace levels of polyterephthalates in laundry detergent products were identified within 20 min without interference from surfactants or other organics. Detection limit was 0.05% by weight in product.
Hydrotropic properties of some short‐chain alkylbenzene‐ and alkylnaphthalene sulfonates
Authors: Burns Robert L.
Published: November 2006

Alkylbenzene sulfonates based on toluene, xylene and cumene, and alkylnaphthalene sulfonates act as hydrotropes in surfactant systems. One measure of hydrotropicity is the amount of hydrotrope required to clear a cloudy detergent formulation; some hydrotropes are more effective than others, depending on the surfactant formulation. Another measure is the modification of the viscosity of surfactant formulations; the change in the viscosity depends on the amount and type of hydrotrope used and on the specific formulation involved. Additionally, alkylnaphthalene sulfonate hydrotropes change the solubility of nonionic surfactants in water, and both types of hydrotrope raise the cloud point of nonionic surfactant solutions; however, the naphthalene‐based hydrotropes are more efficient. Ross‐Miles foam test data are used to compare the foam characteristics of different alkylnaphthalene sulfonates. A critical micelle concentration (CMC) was determined for the alkylnaphthalene sulfonates, but although alkylbenzene sulfonates do show some surface activity, a CMC could not be found for these materials.
Interfacial activity of narrow‐range alcohol oxyethylates
Authors: Blaszczak Jan , Zimoch Jolanta , Hreczuch Wieslaw , Matuszewski Aleksander , Szymanowski Jan
Published: November 2006

Surface and interfacial tension isotherms for narrow‐range distribution ALFOL 1214 alcohol oxyethylates were determined and compared with those obtained for broad‐range alcohol oxyethylates. Various adsorption parameters were estimated. The effectiveness of surface tension reduction decreases when the length of polyoxyethylene hydrophile increases. Micellization is observed at log cmc ranging from −4.7 to −3.3. Effects of the length and distribution of the polyoxyethylene chain on cmc are very small. A minimum of Amin/Nav0.5 is obtained for Nav=8, where Amin and Nav denote the minimum interfacial area occupied by a statistical molecule at the saturated interface and the average degree of oxyethylation, respectively. The interface becomes saturated at pC20=−5.61±0.35, where pC20 denotes the logarithm of concentration required to obtain the surface pressure equal to 20 mNm−1. The highest and lowest values of the surface excess at saturation and the free energy of adsorption, respectively, are obtained for an average degree of oxyethylation equal to 8. Parameters are correlated with the average degree of oxyethylation and the oxyethylene chain distribution parameter according to empirical second‐order polynomials. Small differences in adsorption abilities at the water/air interface are only observed for narrow‐ and broad‐range distributed oxyethylates. The differences become important for adsorption at the hexadecane/water interface. The lowest values of interfacial tension are obtained for narrow‐range oxyethylates with Nav=7 and 8. The Krefeld fabric detergency tests indicated that the best detergency was observed for alcohol oxyethylates with Nav=5–7. Narrow‐range oxyethylates exhibit somewhat better washing abilities than the broad‐range products. No relationship between detergency of alcohol oxyethylates and their abilities to adsorb at the water/air and water/hydrocarbon interfaces is observed.
Surface activity of mixtures of narrow‐range distributed alcohol oxyethylates and sodium dodecylbenzenesulfonate
Authors: Zimoch J. , Błaszczak J. , Szarzyńska K. , Hrecuch W. , Szymanowski J.
Published: November 2006

Surface and interfacial tension, emulsion inversion temperature, and detergency were determined for mixtures of sodium dodecylbenzenesulfonate and narrow‐range distributed alcohol C12−C14 oxyethylates of different hydrophilicity. The mixtures of ionic and nonionic surfactants behave similarly to nonionic and ionic surfactants at the air/water and hydrocarbon/water interfaces, respectively. The air/water interface is mainly occupied by nonionic surfactant molecules. However, the interfacial tensions for mixtures of nonionic and ionic surfactants are similar to those of sodium dodecylbenzenesulfonate. Mixtures of narrow‐range distributed oxyethylates and sodium dodecylbenzenesulfonate have a higher detergency at 40°C than individual components.
Hydrotropic properties of a novel alkylnaphthalene sulfonate
Authors: Burns Robert L.
Published: November 2006

Alkylbenzenesulfonates based on toluene, xylene, as well as cumene, and alkylnaphthalenesulfonates, act as hydrotropes in surfactant systems. A novel sodium diisopropyl‐naphthalene sulfonate (SDIPNS) has been devepoped that contains about 92% diisopropylnaphthalene sulfonate, compared to other diisopropylnaphthalene sulfonate preparations that contain less than 50% diisopropylnaphthalene sulfonate. This material is both a hydrotrope and a surfactant. The color of a 35% solution is light yellow, Gardner 3, significantly lighter than comparable materials. Draves wetting time for a 0.5% solution is about 30 s. The Ross‐Miles foam test (1% solution) indicates a significant level of initial foam, but the foam is unstable. The solubilites of toluene and limonene in SDIPNS are much higher than in other hydrotropes tested. Hydrotropes raise the cloud point of nonionic surfactants; SDIPNS is the most efficient hydrotrope found for this application. Another measure of hydrotropicity is the amount of hydrotrope required to clear a cloudy detergent formulation; this hydrotrope is quite effective. Another measure is the modification of surfactant formulation viscosity; SDIPNS is quite effective. Additionally, SDIPNS changes the solubility of nonionic surfactants in water. SDIPNS is a surfactant as well as a hydrotrope, demonstrating a critical micelle concentration at about 1%.
Micellar thin‐layer chromatographic separation of heavy metal cations: Effect of organic and inorganic additives on migration behavior
Authors: Mohammad Ali , Iraqi Eram , Khan Iftkhar Alam
Published: November 2006

The migration behavior of heavy metal cations on cellulose layers using aqueous micellar, hydro‐organic, and water‐organic‐surfactant mobile phases was investigated. Anionic, cationic, and nonionic surfactant systems were examined over a 0.001–5% concentration range. Brij‐35, a nonionic surfactant capable of forming charged complexes with some metal ions, was identified as the best surfactant. The effect of the presence of organic additives, such as dimethylsulfoxide, dimethylformamide, methanol and acetone, on the mobility of metal ions was also studied. Acetone was found to be the most effective additive at 10% concentration with 3% Brij. Quantitative determination of UO22+ by spectrophotometry after preliminary thin‐layer chromatographic (TLC) separation from Fe3+ and Hg2+ was also performed. A maximal recovery of 93% was obtained. This TLC method is rapid, with development times averaging 2 min.
Synthesis and physicochemical studies of methyl‐12‐[1′‐β‐d‐lactosyl]‐octadec‐9‐ene‐1‐oate: A novel biosurfactant analog
Authors: Kanjilal Sanjit , Maiti S. , Kaimal T. N. B.
Published: November 2006

Synthesis of a new glycolipid and biosurfactant analog, methyl‐12‐[1′‐β‐d‐lactosyl]‐octadec‐9‐ene‐1‐oate (LOD), has been done from easily accessible renewable resources, namely, lactose and ricinoleic acid from castor oil. Surface and thermodynamic properties at the air/water interface including critical micelle concentration (CMC), aggregation number (), maximal densities (Γmax), minimal area per molecule (Amin), surface pressure at the CMC (ΠCMC) free energy of adsorption (ΔGad0), and free energy of micelle formation per mole of monomer unit (ΔGm0) were investigated. The results indicate that this particular glycolipid, because of branching in the hydrophobic chain, has a comparatively large Amin value and hence a very low CMC, aggregation number, and less free energy of micellization and adsorption at the air/water inter‐face than molecules with a straight hydrophobe, for example, n‐dodecyl‐β‐d‐maltoside. The effects of electrolytes (NaCl, KCl, CaCl2, and AlCl3) of the same ionic strength and of increasing ionic strength on the interfacial microenvironment of LOD were also investigated. For the same anion, Cl−, and the same ionic strength, different cations were found to have different effects on the CMC of LOD. With increasing ionic strength, different electrolytes were found to have different effects on the interfacially located, highly hydrated aqueous layer of the LOD micelle. The water structure‐making or‐breaking ability of different cations from the interfacial microenvironment of LOD was found to depend on the charge/radius ratio of the cations.
Effect of sesamin on mitochondrial and peroxisomal β‐oxidation of arachidonic and eicosapentaenoic acids in rat liver
Authors: Umeda‐Sawada Rumi , Ogawa Megumi , Nakamura Mayumi , Igarashi Osamu
Published: November 2006

The effects of dietary sesamin on the hepatic metabolism of arachidonic (AA) and eicosapentaenoic (EPA) acids, were investigated with respect to their β‐oxidation and secretion as triacylglycerol (TG). For 2 wk, rats were fed three types of dietary oils: (i) corn oil (control) group; (ii) FPA group: FPA ethyl esters/rapeseed oil=2∶3; (iii) AA group: AA ethyl esters/palm oil/perilla oil=2∶2∶1, with or without 0.5% (w/w) of sesamin. Dietary sesamin significantly increased the activities of hepatic mitochondrial and peroxisomal fatty acid oxidation enzymes (mitochondrial carnitine acyltransferase I, acyl‐CoA dehydrogenase, and peroxisomal acyl‐CoA oxidase). Dietary FPA increased mitochondrial carnitine acyltransferase I and peroxisomal acyl‐CoA oxidase. Dietary AA, however, had an effect on peroxisomal acyl‐CoA oxidase only. In whole liver and the TG fraction, EPA and AA concentrations were significantly increased by dietary EPA and AA, respectively, and were decreased by dietary sesamin. In hepatic mitochondria and peroxisomes, EPA concentration was increased by dietary EPA, but AA was not changed by dietary AA. The addition of dietary sesamin to the EPA‐supplemented diet significantly decreased the EPA concentration compared to concentrations found with consumption of dietary EPA alone. These results suggest that sesamin increased β‐oxidation enzyme activities and reduced hepatic EPA and AA concentrations by degradation. The stimulating effect of sesamin on β‐oxidation, however, was more significant in the EPA group than in the AA group. Hepatic AA concentration was altered by the joint effect of sesamin through esterification into TG and the stimulation of β‐oxidation.
Effect of fenitrothion on the physical properties of crustacean lipoproteins
Authors: Garcia C. F. , Cunningham M. , González‐Baró M. R. , Garda H. , Pollero R.
Published: November 2006

The effect of the liposoluble organophosphorus insecticide fenitrothion (FS) on lipid packing and rotation of two crustacean plasma HDL was investigated. These lipoproteins, HDL‐1 and HDL‐2, differed in their lipid composition, but their lipid/protein ratios were similar. The rotational behavior of the fluorescent probes 1,6‐diphenyl‐1,3,5‐hexatriene (DPH) and 3‐(p‐(6‐phenyl)‐1,3,5‐hexatrienyl) phenylpropionic acid (DPH‐PA) was used to obtain information about the lipid dynamics in the outer and inner regions, respectively, of the lipid phase of the lipoproteins. Fluorescent steady‐state anisotropy (rs), lifetime (τ), rotational correlation time (τr), and the limiting anisotropy (r∞) of these probes were measured in the lipoproteins exposed to different concentrations of FS in vitro. The results showed the penetration of FS into both plasma lipoproteins, altering the lipid dynamics of the inner as well as the outer regions. The overall effect of the insecticide was to induce an increase in the lipid order in a concentration‐dependent fashion. DPH and DPH‐PA fluorescence‐lifetime shortening indicated that FS increased the polarity of the probe environment, suggesting an enhanced water penetration into the lipoprotein lipid phase, may be due to the induction of failures in the lipid packing. Even in the absence of FS, a higher ordering of the lipid phase was found in HDL‐2 compared to HDL‐1, a fact that might be attributed to a higher percentage of sphingomyelin in HDL‐2.
From gallstones to genes: Two hundred years of sterol research. A tribute to George J. Schroepfer Jr.
Authors: Gibbons Geoffrey F.
Published: November 2006

The origins of cholesterol research can be traced to prerevolutionary France. The discovery of cholesterol as a single substance, present in human gallstones, owes much to the scientists of l'Académie Française, including Lavoisier, who contributed so much to the emergence of chemistry as a modern scientific discipline. Since that time, cholesterol probably has been the most intensively scrutinized natural product of all time, and it has been the subject of Nobel Prizes for several who have studied its structure, biosynthesis, and regulation. The pace of research into cholesterol shows no sign of diminishing, and recent discoveries have led to the recognition that the regulation of cholesterol metabolism is intimately linked with that of other metabolic pathways. Details of these interactions are only just emerging, but it is becoming apparent that under some circumstances it is difficult to reconcile, in a conventional manner, changes in regulatory gene expression with corresponding changes in pathway carbon flux. The present review includes some of our studies on the roles of the transcription factors sterol regulatory element‐binding protein, liver X‐receptor α, and peroxisome proliferator activated receptor α in the coordination of cholesterol and fatty acid synthesis and describes how some of the results obtained can best be interpreted from a Metabolic Control Analysis perspective of the regulation of pathway carbon fluxes.
4‐hydroxy‐3‐methoxycinnamate esters of milkweed oil: Synthesis and characterization
Authors: Harry‐O'kuru Rogers E.
Published: November 2006

The common milkweed (Asclepias syriaca L.) is a new industrial crop. Its seed oil (TAG) is highly polyunsaturated. In the search for novel applications for milkweed seed oil, the olefinic groups in the TAG were oxidized to polyhydroxy TAG via epoxidation and subsequent epoxy ring‐opening reactions. These polyhydroxy TAG exhibit unique industrially desirable emulsoid properties in water. Esterification of the secondary polyhydroxy functionalities of the TAG derivatives of the oil with trans‐4‐hydroxy‐3‐methoxycinnamic acid (ferulic acid) has resulted in the development of novel cinnamate esters of milkweed oil. These cinnamates are also obtainable via direct ring‐opening of the epoxy TAG intermediate with ferulic acid. Among the interesting characteristics of the ester derivatives is their UV radiation‐absorbing property.
Influence of dietary saturated fatty acids on the regulation of plasma cholesterol concentration
Authors: Wilke Michaelann S. , Clandinin M. Thomas
Published: November 2006

The specific effects of individual fatty acids (FA) on plasma cholesterol levels, in the range habitually consumed by humans, is not usually presented by the literature. Conclusions have been made regarding the cholesterolemic effect of individual FA, even though these FA cannot be tested individually. It appears that FA balance of the diet may be more important than individual FA intakes. Variation in plasma cholesterol response to diet is influenced by many factors, such as gene‐nutrient interactions. The effect on human health of current processes used in the food industry that are certain to change dietary fat composition and TG structure is yet to be fully explored. Some of the relevant research regarding dietary fat and plasma cholesterol levels is reviewed.