bluuebunny/crossref_metadata_2025 huggingface dataset:
Fluorescence Anisotropy Selective Technique (FAST): A New Approach to Multicomponent Fluorimetric Analysis
Authors: Bright Frank V.
Published: July 2005

A new analytical approach to multicomponent fluorimetric analysis is presented theoretically and is experimentally demonstrated. The new approach, termed fluorescence anisotropy selective technique (FAST), allows one to directly resolve the individual components in complex mixtures on the basis of differences in the rotational diffusion rates of the components. Importantly, unlike steady-state polarization-based approaches, FAST does not require a priori information regarding the number of individual components. By the use of FAST, the individual emission spectra of the same fluorophore in two different microenvironments can be simultaneously determined even if the fluorescence lifetimes and emission spectra of the two components are extremely similar. To demonstrate the power of FAST, we show results for the simultaneous resolution of dansylamide bound to beta-cyclodextrin and human serum albumin. In this example, the fluorescence lifetimes of the two components are essentially identical.
X-ray Total Reflection Fluorescence Analysis of Iron, Copper, Zinc, and Bromine in Human Serum
Authors: Yap C. T.
Published: July 2005

The method of total reflection fluorescence analysis was used to obtain concentrations of iron, copper, zinc, and bromine in human sera. It was first applied to the commercial control-serum preparation known as Seronorm, and the results obtained were in good agreement with quoted values. The method was then used to determine the concentrations of iron, copper, zinc, and bromine in a random sampling of 62 individuals in an essentially Chinese population. The results are discussed. We feel that this is a suitable method for trace-element analysis of blood in an average laboratory. It is rapid, simple, and economical, besides being multielemental and nondestructive and requiring very small quantities—which seems to be a must in pediatrics.
Quantum-Statistical Modeling of ICPs: He(I)
Authors: Fannin H. B. , Hurly J. J. , Meeks F. R.
Published: July 2005

Relative populations of excited states of He(I) in reduced-pressure ICPs have been shown to obey Fermi-Dirac statistical counting. A single thermodynamic temperature—2000 K—defines the distribution. The experimental relative populations and the Fermi-Dirac distributions agree within fractions of one percent.
Resonant Cell Laser-Based Photoacoustic Densitometer for Thin-Layer Chromatography
Authors: Kawazumi Hirofumi , Yeung Edward S.
Published: July 2005

Photoacoustic spectroscopy was applied to the in situ densitometry of thin-layer chromatographic plates. Fast laser-scanning detection with signal enhancement was demonstrated at a resonant frequency of the cell. The use of phase difference between signal and background provided higher signal-to-noise ratios. Detection limit for Orange G was 170 pg, and the analytical curve was linear over three orders of magnitude.
Entrainment and Transport of Laser Ablated Plumes for Subsequent Elemental Analysis
Authors: Arrowsmith Peter , Hughes Steven K.
Published: July 2005

Several cell designs have been systematically evaluated for gas flow entrainment and transport of laser ablated material to a secondary excitation source for elemental analysis. The best cell is not limited to samples of particular size or shape and is insensitive to sample surface irregularity. An annular gas sheath around the cell results in a transient response sufficiently fast to permit depth and lateral sampling of single samples or rapid throughput of different samples but slow enough to give a steady signal with laser repetition rates ≥10 Hz. Entrainment and transport of ablated particulates have been investigated experimentally and by model calculation for a test material (Mo metal). The equations for predicting diffusive and gravitational loss of particles in a horizontal tube are presented and discussed. The major loss mechanism appears to be gravitational deposition of relatively large particles formed during ablation and possibly by coalescence within the transfer tube. Entrainment of ablated Mo by the cell and mass transport from the cell to the secondary source were determined to be ∼90% and ∼40% efficient, respectively. Shot-to-shot fluctuation in particle size may cause corresponding variation in transport efficiency when the upper end of the ablated particle size distribution exceeds the size limit for particle transport.
Clean Room and Microwave Digestion Techniques: Improvement in Detection Limits for Aluminum Determination by GF-AAS
Authors: Skelly E. M. , Distefano F. T.
Published: July 2005

A rapid, precise, and accurate method for the determination of aluminum in part-per-billion concentrations in biological materials using graphite-furnace atomic absorption spectroscopy has been developed. In order that the necessary accuracy and precision for the analysis of aluminum in bone and brain tissue could be obtained, reduction of laboratory environmental contributions to the aluminum blank was required. Use of a closed-vessel microwave digestion system and a clean room for sample preparation accomplished this goal by reducing Al concentrations in the digestion blanks from 10 ppb to 1 ppb. Digestion time was decreased from many hours to several minutes, and the amount of acid required for digestion was reduced by 70%. Using less nitric acid improved precision in the analyzed solutions by significantly extending the lifetime and consistency in performance of the graphite tube atomizer.
Analytical Performance and Transport Studies Using Spark Sampling Followed by ICP Excitation with a Sequential Spectrometer
Authors: Prell L. J. , Koirtyohann S. R.
Published: July 2005

It was established that a high-voltage spark is a viable method of sampling iron and aluminum-based alloys using a sequential spectrometer ICP. Calibration curves were linear over at least four orders of magnitude, detection limits were in the parts per million range in the solid, and precisions of 1–3% were readily demonstrated when the base metal was used as an internal standard. Fifteen elements could be determined in a three-minute burn. The best analytical performance was obtained when the gas flow sweeping particles to the plasma passed through the counter electrode. Experiments with a cascade impactor showed that most of the material reaching the plasma was in small particles (<0.4 μm), with a total sample transport rate of about 0.5 μg/s . Particles reaching the plasma were examined by the scanning electron microscope and appeared to be mostly aggregates of very small spheres of 500–1500 Å diameter. Under nonoptimum conditions, large spheres (∼1–5 μm diameter) and ablated material of irregular shape made up a significant amount of the transported material. The analytical performance is affected by particle size distribution, particle type, and sample transport rates.
Application of Two-Dimensional NMR Spectroscopy to the Study of Substituted Piperidine Derivatives. Part I: L-Methyl-2-Piperidine Methanol
Authors: Cholli Ashok L. , Pennino Donald J.
Published: July 2005

One- and two-dimensional NMR experiments are used to study substituted piperidine derivatives in both free base and salt form. The investigation of 1-methyl-2-piperidine methanol has resulted in stereostructural elucidation of this compound in the salt form.
A Sensitive Multichannel Detection System for Surface Raman Spectroscopy
Authors: Meier M. , Carron K. T. , Fluhr W. , Wokaun A.
Published: July 2005

A cooled multichannel detector has been developed that is based on a second-generation image intensifier tube and a Reticon photodiode array. The sensitivity of the device is characterized and discussed in terms of the limiting noise sources. For use in Raman spectroscopy, the detector has been optically matched to a triple spectrograph. Signal-to-noise ratios obtained with this detection system are compared with those of typical photon counting instruments. The required integration time (∼1000 s) and substrate properties to record unenhanced Raman signals from an adsorbed molecular monolayer on a surface are discussed.
Porous-Core Electrode for Emission Spectroscopy
Authors: Wang M. S.
Published: July 2005

A core was made of porous graphite to fit a preformed electrode. This porous-core electrode replaces old popular methods using graphite powder as an absorbent to accomplish concentration of liquid samples, but without causing contamination problems of Teflon® ware. When the amount of sample solution is not limited, a concentration of several thousand times is possible, to extend detection limits required by the modern electronics industry. High-purity water, solvents, volatile acids, and alkali were concentrated, and ultra trace impurities were determined. Some organic material can be ashed at 400°C on the electrode for arcing. Boron in trichlorosilane was separated with an addition of mannitol and routinely determined in low ppba range. The cost of this operation is a small fraction of that for new instrumentation required for achieving these sensitivities. The old spectrograph with a dc arc source unit and photographic detection has found some applications to meet new stringent requirements. The technique should be able to be easily applied to the determination of metallic impurities in trichlorosilane, dichlorosilane, hydrogen chloride, and others.
Design Considerations and Preliminary Characterizations of a Kilowatt-Plus Microwave-Induced Plasma
Authors: Cull Kevin B. , Carnahan Jon W.
Published: July 2005

A high-powered helium microwave-induced plasma was developed, and preliminary characterizations are presented. This kilowatt-plus microwave-induced plasma (KiP-MIP) was contained in a helical flow quartz torch. Power was transferred via waveguides from a 3.0-kW, 2.45-GHz, 120-pulses-per-second microwave generator to a waveguide-to-coaxial converter. A modified Beenakker TM010 resonator cavity was used to focus the energy. Effects of the magnitude of applied power on helium line emission intensities were studied, as well as comparisons of the temporal output of generator output and helium line emission. Introduction of gaseous halogens (Cl2, CBr4) produced intense ion emission which follows the intensity ratios commonly observed in He-MIPs.
Site-Selection Fluorescence Spectrometry of Polycyclic Aromatic Hydrocarbons in Vapor-Deposited Argon Matrices
Authors: Macdonald Brian F. , Hammons John L. , Gore Randy R. , Maple Jon R. , Wehry E. L.
Published: July 2005

The use of tunable laser excitation to effect significant sharpening in the inhomogeneously-broadened fluorescence spectra of polycyclic aromatic hydrocarbons (PAHs) isolated in argon matrices at 15 K is reported. The broad-band-excited fluorescence spectra of most PAHs in solid argon exhibit complex multiplet structures assumed due to the location of individual PAH molecules in different types of discrete “sites” in the polycrystalline matrix. Under laser excitation, the fluorescence spectra of PAHs are strongly dependent on excitation wavelength. For most PAHs, there exists an “optimum” excitation wavelength, at which a “single-site” fluorescence spectrum comprising one intense feature having a bandwidth of SO cm−1 or less is obtained. The excitation and emission wavelengths for site-selection fluorescence of eleven PAHs matrix isolated in argon are tabulated, and the trade-offs implicit in choice of optimum excitation wavelengths for site-selection fluorometric detection of PAHs in multicomponent samples are addressed. Quantitative results for five constituents of a sixteen-component standard reference material exhibit excellent agreement with certified values.
Low-Pressure Degenerate Four-Wave Mixing Spectroscopy with Flame Atomization
Authors: Nolan T. G. , Koutny L. B. , Blazewicz P. R. , Whitten W. B. , Ramsey J. M.
Published: July 2005

A combination of degenerate four-wave mixing spectroscopy and a low-pressure sampling technique has been studied for isotopic analysis in an air-acetylene flame. Hyperfine spectra of D lines of sodium and several mixtures of lithium isotopes obtained in this way are presented.
Laser-Induced Intrinsic and Dye-Sensitized Photoconductivity in β-Carotene Glass
Authors: Tierney Michael , Lubman David M.
Published: July 2005

Photoconductivity is studied in thin films of β-carotenc glass, an amorphous mixture of β-carotene isomers. Photocurrents are produced by a pulsed dye laser and are on the order of microamperes. The mechanism for production of photocurrent is believed to be two-photon internal photoemission. Photoconduction is also investigated in a variety of organic dyes. These dyes and chlorophyll a are then used to sensitize the photoconduction of β-carotene glass to longer wavelengths than it would normally photoconduct. It is believed that chlorophyll and phthalocyanine donate holes to the carotene after photoexcitation, while the other dyes undergo an energy transfer process. The voltage, laser intensity, and wavelength dependences of the photocurrents are examined and compared with results from earlier studies.
Modulation of Commercial Hollow Cathode Lamps by a Magnetic Field in a Magnetron Configuration
Authors: Simonneau Regis , Sacks Richard
Published: July 2005

An oscillating magnetic field generated by an underdamped capacitive discharge in a large coil is used to modulate the intensity of commercial hollow cathode lamps. Lamps are oriented in the coil so that the magnetic field is coaxial with the hollow cathode. This results in a pseudo-magnetron configuration where the magnetic field is normal to the electric field in the cathode space charge. This configuration results in ExB and diamagnetic drift motions of positive ions and electrons, so that these particles are trapped in circular orbits parallel to the cathode surface. Radiation intensity vs. time profiles are presented for Mn, Cr, Hg, Ag, and V lamps. With relatively high magnetic field strengths and low lamp current, periods of very low lamp intensity are obtained with high-intensity spikes occurring when the magnetic field changes direction. With lower field strengths and higher lamp current, a variety of patterns of intensity modulation is observed.
Differential Photothermal Deflection Spectroscopy Using a Single Position Sensor
Authors: Spear J. D. , Russo R. E. , Silva R. J.
Published: July 2005

A differential dual-beam photothermal deflection spectrometer using a single position sensor is described. An excitation and a probe laser beam are directed simultaneously into a sample solution and a reference solution to provide real-time background correction. The probe beam that passes through the reference cell is folded back into the path of the sample-cell probe beam in such a way that only one position sensor is needed to monitor the deflection in both cells. Nd3+ solutions are used to demonstrate the effect of background correction and the sensitivity of this dual-beam photothermal deflection arrangement.
Modifications of a Diffuse Reflectance Cell to Allow the Characterization of Carbon-Supported Metals by DRIFTS
Authors: Venter J. J. , Vannice M. A.
Published: July 2005

Carbon-supported metal catalysts have been investigated with the use of Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS) for the first time. In order to successfully pretreat such catalysts, obtain IR spectra, and characterize these highly opaque materials, one must make extensive modifications of DRIFTS cells, commercial or otherwise. These modifications include the arrangements for capability and ease of sample height adjustment from outside the spectrometer chamber, the improvement of the thermal performance of the cell to provide high temperatures in flowing H2, the accurate measurement of sample temperature, and the guarantee of adequate gas flows through the catalyst bed. These capabilities are essential for proper in situ investigations of catalysts. This improved DRIFTS cell was used to follow the thermal decomposition of carbon-supported Os3(CO)12 for the first time. The cluster transformed rapidly in flowing H2 to a more stable H4Os4(CO)12 terra-nuclear cluster, similar to the reaction in solution, which then further decomposed at higher temperatures. The spectrum of CO adsorbed on carbon-supported Os crystallites after complete decomposition was also obtained, and it showed the presence of only reduced metallic Os. These findings provide the first IR evidence for the relative inertness of oxygen-free carbon, compared to oxide supports, towards the formation of stable, positive-valent Os species. In order to facilitate the effective use of DRIFTS for characterization of opaque materials in general, our modifications to a commercial DRIFTS cell are described and representative spectra are shown.
Examinations of the Matrix Isolation Fourier Transform Infrared Spectra of Organic Compounds: Part XI
Authors: Coleman W. M. , Gordon Bert M.
Published: July 2005

Matrix isolation Fourier transform infrared information has been presented on a series of aliphatic amines, anilines, and amides. The absorptions associated with NH stretches are found at essentially the same energies in both the vapor phase (VP) and matrix isolation (MI) phase. Both the VP and MI values are found at higher energy than the solid state (SS) phase. The similarity of the values for the MI and VP phases is a departure from results found previously for other types of organic compounds. The carbonyl absorptions for the amides (MI) were found to be intermediate between the VP (high) and SS (low) values. This is consistent with established trends for other carbonyl containing compounds. The absorptions for carbonyl groups for the majority of the compounds appear as split absorptions on the order of 20 cm−1 peak to peak. These split absorptions were ascribed to intramolecular hydrogen bonding and rotational conformer isolations. Minor aggregation effects were found to occur as band broadening effects when the ratio of matrix gas (argon) to analyte dropped below 1000:1.
Fiberoptic Oxygen Sensor Based on Fluorescence Quenching and Energy Transfer
Authors: Sharma Ashutosh , Wolfbeis Otto S.
Published: July 2005

A new type of oxygen sensor is described that is based on electronic energy transfer from a donor (whose fluorescence is efficiently quenched by molecular oxygen) to an acceptor (which is less affected by oxygen). We use pyrene as the donor and perylene as the acceptor. The fluorescence emission band of the donor shows good overlap with the absorption band of the acceptor. When excited at 320 nm, the two-fluorophore system shows strong fluorescence at 476 nm, where pyrene itself is nonfluorescent. Although perylene is not efficiently quenched by oxygen, the system strongly responds to oxygen because fluorescence is quenched with an efficiency that by far exceeds the quenching efficiency for pyrene or pyrelene alone. The principle has been applied in order to devise a fiberoptic oxygen sensor by incorporating the two dyes in a polymer matrix that has been attached to the end of an optical fiber. Oxygen can be detected in the 0–150 kPa range with ±0.3 kPa precision. The detection limit is 60 Pa oxygen.
Characterization of Solution-Cast Extracts from Biomer® by FT-IR and ESCA
Authors: Grobe George L. , Gardella Joseph A. , Chin Roland L. , Salvati Lawrence
Published: July 2005

Biomer® extracts have been cast from varying polarity solvents in an attempt to control surface composition and morphology. This polymer has previously been described as a block copolymer. FT-IR has been utilized to probe bulk and surface bonding and composition in these resulting extract cast films. FT-IR data was combined with x-ray photoelectron spectroscopic measurements to provide a detailed description of the surface composition. Results will show that a polydimethysiloxane contaminant in Biomer® can be preferentially segregated to the surface as a function of the Hildebrand parameter of the solvent that Biomer® extracts are cast from. Extracts of Biomer ® as solution-cast from varying polarity solvents had many different components. This suggests that Biomer® resembles a blend of copolymerized segments with different compositions and molecular weights, with a significant number of impurities including DMS.
Downstream Migration, Rearing Abundance, and Pool Habitat Associations of Juvenile Steelhead in the Lower Main Stem of a South-Central California Stream
Authors: Spina Anthony P. , Allen Mark A. , Clarke Michael
Published: July 2005

Unlike river main stems in the northern geographic range of steelhead Oncorhynchus mykiss, the surface flow of main stems in south-central and southern California can be extremely low, intermittent, or entirely lacking during the dry season. This has led to a general belief among biologists that main stems provide only migratory habitat, which has created challenges for fishery managers because some main stems are now perennial as a result of the continuous release of treated municipal wastewater. During 2000–2002, we monitored juvenile abundance and downstream migration of the south-central California coast evolutionarily significant unit of steelhead in the lower main stem (reaches proximate to the ocean) of a south-central California stream. This stream has a continuous discharge of tertiary-treated municipal wastewater that forms most, if not all, of the dry-season living space for steelhead. Our principal finding indicates that this artificial discharge provides oversummering habitat for juvenile steelhead.
Plasma beam alignment for the large‐area substrates: Equipment and process
Authors: Yaroshchuk O. V. , Kravchuk R. M. , Dobrovolskyy A. M. , Liu P. C. , Lee C. D.
Published: July 2005

Abstract— We have developed an effective method for liquid‐crystal alignment of the large‐area substrates. This method is based on the oblique treatment of the alignment substrates with a “sheet” of accelerated plasma generated by the anode layer source of the “race track” geometry. During this treatment, the substrate or source is cyclically translated in the direction perpendicular to the plasma “sheet.” This method provides planar, tilted, and vertical liquid‐crystal alignment with excellent uniformity and reproducibility and easy axis control in the azimuthal and polar planes.
Lanthanide‐doped sol‐gel‐derived films fabricated in mesoporous anodic alumina
Authors: Molchan I. S. , Gaponenko N. V. , Thompson G. E.
Published: July 2005

Abstract— Porous anodic alumina films with controllable morphology were fabricated under varied anodizing conditions and examined by scanning electron microscopy and photoluminescence analysis. Erbium‐, terbium‐, and europium‐doped xerogel films were formed inside the porous layer. Strong visible and infrared photoluminescence from the erbium‐doped xerogel/porous anodic alumina structure was observed. An electroluminescent cell based on xerogel/porous anodic alumina structure was also developed, with terbium‐ and europium‐related electroluminescence investigated.
A novel approach to LCD optimization
Authors: Yakovlev Dmitriy , Chigrinov Vladimir , Kwok Hoi Sing
Published: July 2005

Abstract— A novel approach to optimization liquid‐crystal displays (LCDs) is presented. The optimization module allows for a prediction with a high accuracy for the best results, which can be obtained for one or the other configuration of the polarizers and phase retarders in various electro‐optical modes, if the LC parameters and the operating voltages are fixed. The module is a part of our program, MOUSE‐LCD, which is efficient software for LCD optimization and modeling.
3‐D Holographic video image forming by acousto‐optical method
Authors: Petrov Vladimir V.
Published: July 2005

Abstract—In this work, the principle of 3‐D holographic moving‐image reconstruction is considered, which is based on the acousto‐optical interaction effect. The excitation by a multi‐element system of transducers acoustical field represents, in fact, an electronically controlled “thick” optical hologram. The results of the numerical simulation of the image‐reconstruction process are presented. The advantages and shortcomings of the suggested method are discussed.
Linear Datalog and Bounded Path Duality of Relational Structures
Authors: Dalmau Victor
Published: July 2005

In this paper we systematically investigate the connections between logics with a finite number of variables, structures of bounded pathwidth, and linear Datalog Programs. We prove that, in the context of Constraint Satisfaction Problems, all these concepts correspond to different mathematical embodiments of a unique robust notion that we call bounded path duality. We also study the computational complexity implications of the notion of bounded path duality. We show that every constraint satisfaction problem $\csp(\best)$ with bounded path duality is solvable in NL and that this notion explains in a uniform way all families of CSPs known to be in NL. Finally, we use the results developed in the paper to identify new problems in NL.
The succinctness of first-order logic on linear orders
Authors: Grohe Martin , Schweikardt Nicole
Published: July 2005

Succinctness is a natural measure for comparing the strength of different
logics. Intuitively, a logic L_1 is more succinct than another logic L_2 if all
properties that can be expressed in L_2 can be expressed in L_1 by formulas of
(approximately) the same size, but some properties can be expressed in L_1 by
(significantly) smaller formulas.
We study the succinctness of logics on linear orders. Our first theorem is
concerned with the finite variable fragments of first-order logic. We prove
that:
(i) Up to a polynomial factor, the 2- and the 3-variable fragments of
first-order logic on linear orders have the same succinctness. (ii) The
4-variable fragment is exponentially more succinct than the 3-variable
fragment. Our second main result compares the succinctness of first-order logic
on linear orders with that of monadic second-order logic. We prove that the
fragment of monadic second-order logic that has the same expressiveness as
first-order logic on linear orders is non-elementarily more succinct than
first-order logic.
Adsorptive Separation of Oils
Authors: Proctor A. , Brooks D. D.
Published: July 2005

Vegetable oil refining processes, specifically, silica refining and bleaching, require a working understanding of adsorption or more specifically the physico‐chemical interaction between sorbent, substrate and contaminants. An understanding of adsorption theory and the factors affecting adsorption is useful in controlling these processes. Isotherms have been used as mathematical models to describe the relationship between adsorbed and non‐adsorbed molecules. The Langmuir isotherm theoretically describes oil pigment binding as reversible, monolayer chemisorption, where all adsorption sites are energetically equal. However, many systems conform to a Langmuir isotherm without these suppositions necessarily holding true. Langmuir behavior may provide useful practical information on the variables affecting the adsorption, but it does not provide proof of the adsorption mechanism. The Freundlich isotherm is supposed to describe reversible adsorption of a single solute at equilibrium at a fixed temperature. It also has been successfully used to describe pigment adsorption from vegetable oil and, likewise, has empirical value in describing the effect of processing variables on adsorption performance. In reality, pigment binding onto adsorbent clays is irreversible and there will be more than one oil solute competing for adsorption sites. Adsorptive binding of solute to adsorbent involves a number of forces, including chemisorption and physisorption, all of which affect bleaching efficiency. Adsorbent dosage, acidity, moisture in the system, temperature and pressure, all key factors that can be used to control the adsorption process.
Chemistry of Fatty Acids
Authors: Scrimgeour Charlie
Published: July 2005

Oils and fats consist of triacylglycerols containing a range of fatty acids. Commodity oils are predominantly sources of C16–C18fatty acids (corn, cottonseed, groundnut, linseed, olive, palm, rape, sesame, soybean, sunflower), whereas some contain short‐ and medium‐ chain fatty acids (butter, coconut, palm kernel) or long‐chain fatty acids (fish) in various proportions. Fatty acid and triacylglycerol composition determines the physical, chemical, and nutritional properties of oils and fats and their uses in both food and oleochemical manufacture. Fatty acids generally contain only two types of reactive functional groups, the terminal carboxyl and a number of carbon–carbon double bonds. Reaction at, or modification of, these groups is central to their industrial use. Oxidation (particularly oxidative degradation of edible fats), reduction (particularly partial hydrogenation), and reactions used to produce surfactants and oleochemicals (epoxidation, ozonolysis, metathesis, sulfonation, production of nitrogen‐containing derivatives) are described. A current concern is the environmental impact of industrial chemistry and new processes that use less solvent, milder conditions, and renewable resources, and that produce less waste are required. Oils and fats are a major renewable resource, and environmental concerns may be met through the use of enzymes and improved chemical catalysts as alternatives to current technology. Novel chemistry of oils, fats,and fatty acid derivatives with potential industrial application is highlighted, particularly that introducing new functionality to the alkyl chain.
Flax Oil and High Linolenic Oils
Authors: Przybylski Roman
Published: July 2005

Oils with different composition of fatty acids are available from plants. Sources of oils with high content of linolenic acid have recently received special attention because of the abnormal ratio of omega‐3 to omega‐6 fatty acids present in consumed oils and fats. Available commercial oils and fats mainly contain linoleic acid, and not many oils offer linolenic acid as a source of omega‐3 fatty acids. In this chapter, oils high in linolenic acid, namely, flax, perilla, camelina, and chia oils, are discussed. Content of linolenic acid in the oils reported is above 50%, and contribution of polyunsaturated fatty acids for all of them is above 70%. Oilseeds and oils from these crops are produced on an industrial scale, and they are available as health food products. Chemical composition, physical properties, and typical oil parameters for these oils are also discussed.
Structural Effects on Absorption, Metabolism, and Health Effects of Lipids
Authors: Christophe Armand B.
Published: July 2005

The structure of fatty acid‐containing lipid classes is defined as the grouping or positioning of fatty acids on the alcohol backbone. Alcohol backbones considered are glycerol, phytosterols/‐stanols, and sucrose. Health‐related nutritional effects of food lipids depend on the fatty acids they contain (not covered here), on the alcohol backbone, on the number of fatty acids esterified on the alcohol backbone if applicable (triacylglycerols vs. diacylglycerols vs. monoacylglycerols), and on the position the fatty acids occupy. The specificity of the lipases that are present in the intestinal tract are a major determinant of the digestion products that will be formed. Different digestion products will react differently in the intestinal lumen and after absorption will be metabolized differently in the intestinal cells. Specificity of lipases in combination with different handling of different fat digestion products are at the basis of structure‐related effects of food lipids. The position of fatty acids in triacylglycerols (inner or outer) can have an effect on digestibility (for saturated fatty acids), route of transport (for medium chain fatty acids), conversion in higher unsaturated fatty acids (for parent essential fatty acids), chylomicronemia, cholesterolemia, and atherogenicity. The well‐known cholesterolemic and atherogenic effects of different fatty acids are more pronounced when these fatty acids are esterified at the inner position of triglycerides. Partial glycerides have nutritional effects different from triglycerides with the same fatty acid composition. The nature of the alcohol backbone of food fats is also extremely important for their health‐related nutritional effects. Phytosterol/‐stanol esters, for instance, have cholesterol‐lowering effects, and sucrose polyesters cannot be absorbed from the intestinal tract.
Vegetable Oils
Authors: Gunstone Frank D.
Published: July 2005

This chapter provides a survey of the major and minor vegetable oils covering, in particular, their fatty acid and triacylglycerol composition and their production levels. This survey is supported with a number of related topics that include the biosynthesis of triacylglycerols in the plant kingdom, the important minor components present in vegetable oils, the need to modify the natural oils, and the ways in which this can be achieved. Finally, there is a brief account of current production levels of the major vegetable oils and of the trade in these commodities.
Polymorphism in Fats and Oils
Authors: Sato Kiyotaka , Ueno Satoru
Published: July 2005

This chapter reviews the polymorphism of principal triacylglycerols in single and binary mixture states. First, basic concepts of fat polymorphism, namely, thermal stability, subcell structure and chain length structure are explained together with phase equilibria of binary mixture systems. Then, polymorphic behavior of principal triacylglycerols are described. The phase behavior of the mixture systems of the principal TAGs is discussed with an emphasis of the influence of the polymorphism.
Crystallization of Fats and Oils
Authors: Metin Serpil , Hartel Richard W.
Published: July 2005

Control of crystallization of lipids is important in many food products, including margarine, chocolate, butter, and shortening. In these products, the aim is to produce the appropriate number and size distribution of crystals in the correct polymorphic form because the crystalline phase plays a large role in such food properties as appearance, texture, spreadability, and flavor release. Thus, understanding the processes that control crystallization is critical to controlling quality in these products. Controlling crystallization requires an understanding of the driving force that leads to crystallization, the process of forming the crystalline phase (nucleation), and then subsequent crystal growth and polymorphic transformation to obtain the final crystalline phase volume in equilibrium with the remaining liquid fat. Because of the complex composition of most natural fats, our understanding of these processes remains somewhat uncertain.
Cottonseed Oil
Authors: O'Brien Richard D. , Jones Lynn A. , King C. Clay , Wakelyn Phillip J. , Wan Peter J.
Published: July 2005

Cottonseed oil, America's original vegetable oil, dominated the United States vegetable oil market for almost 100 years. Cottonseed is a by‐product of cotton and difficult to process and refine due to its unique seed structure and high content of natural pigment. Through research and experimentation, chemists have developed a clear, odorless, bland flavored cottonseed oil and a creamy, white shortening that set the standards for edible fats and oils worldwide. The scientific and technical advances developed to process cottonseed and cottonseed oil became the cornerstones of the edible fats and oils industry as it is known today. Numerous processes were developed or perfected especially for cottonseed oil and cottonseed which later found application for other oils and oilseeds. These processes include screw press extraction, pre‐press solvent extraction, and direct and expander‐solvent extraction for the crude oil; caustic and miscella refining; fractionaton via winterization; deodorization; bleaching; hydrogenated basestock system; blending and formulating with various basestocks to achieve the desired performance and characteristics, etc. Today, vegetable oil processors worldwide have a wide range of raw materials to choose from, but cottonseed pioneered the American vegetable oil industry.
Deodorization
Authors: De Greyt W. , Kellens M.
Published: July 2005

All crude oils and fats, obtained after rendering, crushing, or solvent extraction, inevitably contain variable amounts of nonacylglycerol constituents such as free fatty acids, sterols, tocopherols, hydrocarbons, pigments (gossypol, chlorophyls), vitamins, contaminants (pesticides, polycyclic aromatic hydrocarbons, etc.), heavy metals, glycolipids, and protein fragments as well as resinous and mucilaginous materials.

The objective of the refining process is to remove the unwanted constituents from the oil with the least possible negative effect on triacylglycerols and minimal loss of the desirable constituents. To be able to meet the ever‐increasing quality requirements (mainly regarding the nutritional quality) and to further reduce the processing costs, equipment manufacturers are obliged to continuously improve their technology. Industrial deodorization technology and operating conditions have been adapted to meet the required organoleptic and nutritional quality standards.
Shortenings: Types and Formulations
Authors: O'Brien Richard D.
Published: July 2005

Shortening was once the reference to naturally occurring fats that are solid at room temperature and were used to “shorten” or tenderize baked foods. The material makeup of shortening has changed from a natural fat to blends of oils with hard fats to hydrogenated liquid oils to blend with additives such as emulsifiers, antioxidants, antifoamers, metal scavengers, and antispattering agents. Shortenings are still intended to tenderize baked goods and to provide other functional attributes. Today's shortenings are essential ingredients in every type of prepared food product. Shortenings affect the structure, stability, flavor, storage quality, eating characteristics, and eye appeal of the foods prepared.

Specific topics discussed in this chapter are source oils, shortening attributes, a base stock system that uses a limited number of hydrogenated stocks for blending, formulations, crystallization, plasticized shortening consistency, liquid opaque shortenings, and shortening chips and flakes.
Fatty Acids and Derivatives from Coconut Oil
Authors: Gervajio Gregorio C.
Published: July 2005

Coconut oil and palm kernel oil are import feedstocks in the oleochemical industry. Oleochemicals are defined as chemicals made from oils. Coconut oil is well positioned because it has the unique advantage of having its fatty acid composition falling within the carbon‐chain spectrum desired for the production of oleochemicals. C12–C14 fractions are highly sought after. The caproic to capric (C6–C10) fatty acid fractions are good materials for plasticizer range alcohol and for polyol esters. The latter are used in high‐performance oil for jet engines and for a new generation of lubricants. These fractions are also basic to the preparation of medium‐chain triglycerides, a highly valued dietary fat. The C12–C18 fractions are the primary raw materials for detergent‐grade fatty alcohols.

Coconut fatty acids can be converted to other derivatives. Principles and methods in the manufacture of various oleochemicals are discussed.

Detailed information is given for the following: fatty acids and fat‐splitting procedures; methyl esters and their advantages; fatty alcohols, which are gaining favor as surfactants because they are biodegradable and a renewable resource; glycerine; monoalkyl phosphates, which are used for fireproofing, foam inhibitors, in extreme pressure lubricants, and for cosmetic preparations; and alkanolamides, used as nonionic surfactants. Preparation of other surfactants prepared from vegetable oils is discussed. These surfactants find broad use in all industries, for example, as the main ingredients in detergents, emulsifiers and sanitizers in the food industry, and as flotation agents in the mining industry. Tertiary amines are used as starting materials for the manufacture of quaternary ammonium compounds and in the preparation of amine oxides. These oxides are used in cosmetic preparation.
Leather and Textile Uses of Fats and Oils
Authors: Kronick Paul , Kamath Y. K.
Published: July 2005

Although most of the 20‐odd steps of leathermaking use fats and oils as detergents, by far the majority of these materials are used as additives to soften leather. Oils are usually applied in aqueous emulsions while the leather is still wet from tanning. Several oils are conventionally used, often made self‐emulsifying by partial sulfation or sulfonation by treating with sulfuric acid. These oils are called
fatliquors
.

Aside from softening, a smaller amount of oils and fats as detergents are also used in preliminary cleaning of the raw skins and hides; to suspend lime particles, buffer the alkaline solution that removes the epidermis and hair, and suspend these materials when they come off; to remove grease; to tan certain types of leather; and to control the penetration of dyes.

The discussion shows the importance of oils and fats in the processing of textiles. As a result of oxidative stability, synthetic oils have superseded their natural counterparts. However, fatty acids from natural oils still play an important role in the processing of textiles. There is considerable pressure on the textile industry to reduce the amounts of these additives, or to eliminate them completely, because of the environmental implications of the effluents. In response to this, considerable effort is being made in the industry to develop additive‐free processes.
Confectionery Lipids
Authors: Shukla Vijai K. S.
Published: July 2005

Chocolate not only has nutritional value, but it is an emotional confection—it can be used to comfort, apologize, celebrate, and as a token of gratitude. Chocolate is derived from the cocoa bean, which in turn comes from the cacao (ka‐ka‐o) tree,
Theobroma cacao
. Theobroma means “food of the gods,” and cacao is as rich in history as it is in flavor.

Confection science is extremely complicated because of the great diversity of triacylglycerol molecules and the presence of several surface‐active components that play a major role in defining the quality of the final products.

Sophisticated analytical methodologies play a major role in unfolding the mysteries of speciality fats in chocolate. Recent harmonization of European Union law for speciality fats in chocolates will demand newer sources of exotics to be evaluated to fulfill future requirements.
Packaging
Authors: Caudill Vance
Published: July 2005

Packaging systems for oils and fat products have become more complex as the demands for containing, protecting, and identifying products have increased for manufacturers. The packaging system must be designed to produce an economical product that satisfies regulatory guidelines, consumer demands, and production requirements. This chapter discusses the design methodology for implementing an integrated oil‐fat packaging line and the major line components and includes a description of typical edible oils lines and bulk filling lines. A further discussion of the design methodology explores the three phases involved: conceptual‐definition phase, preliminary engineering, and final engineering.
Tree Nut Oils
Authors: Shahidi Fereidoon , Miraliakbari Homan
Published: July 2005

Tree nut oils are primarily composed of triacylglycerols, but also contain diacylglycerols, monoacylglycerols, free fatty acids, and other minor components, including natural antioxidants and fat‐soluble vitamins. The chemical composition of edible fats and oils largely determines their stability, quality, nutritional value, sensory properties, and potential health effects. Tree nuts, in many cases, provide rich sources of food lipids; up to 75% lipid on a weight basis. With a few exceptions, tree nut lipids exist as oils at room temperature. Generally, tree nuts are rich in monounsaturated fatty acids, predominantly oleic acid, but contain much lower amounts of polyunsaturated fatty acids, predominantly linoleic acid and small amounts of saturated lipids. In many parts of the world, such as the Middle East and Asia, tree nuts are cultivated for use as oil crops and are important sources of energy and essential dietary nutrients as well as phytochemicals. Tree nut oils are also used as components of some skin moisturizers and cosmetic products.

Tree nuts, tree nut oils, and tree nut byproducts (defatted meals and hulls) are known to contain several bioactive and health‐promoting components. Epidemiological evidence indicates that the consumption of tree nuts may exert several cardioprotective effects, which are speculated to derive from their lipid component that includes unsaturated fatty acids, phytosterols, and tocols. Recent investigations have also shown that dietary consumption of tree nut oils may exert even more beneficial effects than consumption of whole tree nuts, possibly due to the replacement of dietary carbohydrate with unsaturated lipids or other components present in the oil extracts. Tree nut byproducts are used as sources of dietary protein and as health‐promoting phytochemicals such as natural antioxidants. This chapter summarizes the characteristics and potential health effects of several tree nut oils and their byproducts, including almond oil, hazelnut oil, pecan oil, walnut oil, pistachio oil, Brazil nut oil, pine nut oil, and macadamia nut oil, among others. Protein compositions of tree nut byproducts are also discussed collectively at the end of this chapter, with emphasis on the completeness of these proteins based on their amino acid compositions.
Vegetable Oils in Production of Polymers and Plastics
Authors: Narine Suresh S. , Kong Xiaohua
Published: July 2005

Plastics are ubiquitous in our modern environment. In fact, plastic as a class of material is manufactured in greater abundance than both steel and paper. As the world arrives closer to the global realization of our dwindling fossil resources, however, the fact that plastics are produced mainly from petroleum derivatives has become a source of concern and efforts to utilize renewable feedstock sources. This communication provides a short introduction to the use of renewable feedstock for the production of polymers, and focuses on the use of triacylglycerol oils as feedstock for the production of polyurethanes and chemicals used as additives in other plastics.
Lipid Oxidation: Measurement Methods
Authors: Shahidi Fereidoon , Zhong Ying
Published: July 2005

Numerous analytical methods are routinely used for measuring lipid oxidation in foods. However, there is no uniform and standard method for detecting all oxidative changes in all food systems. Therefore, it is necessary to select a proper and adequate method for a particular application. The available methods to monitor lipid oxidation in foods can be classified into five groups based on what they measure: the absorption of oxygen, the loss of initial substrates, the formation of free radicals, and the formation of primary and secondary oxidation products. A number of physical and chemical tests, including instrumental analyses, have been employed in laboratories and the industry for measurement of various lipid oxidation parameters. These include the weight‐gain and headspace oxygen uptake method for oxygen absorption: chromatographic analysis for changes in reactants; iodometric titration, ferric ion complexes, and Fourier transform infrared (FTIR) method for peroxide value; spectrometry for conjugated dienes and trienes, 2‐thio‐barbituric acid (TBA) value,
p
‐anisidine value (
p
‐AnV), and carbonyl value; Rancimat and Oxidative Stability Instrument method for oil stability index; and electron spin resonance (ESR) spectrometric assay for free‐radical type and concentration. Other techniques based on different principles, such as differential scanning calorimetry (DSC) and nuclear magnetic resonance (NMR), have also been used for measuring lipid oxidation. In addition, sensory tests provide subjective or objective evaluation of oxidative deterioration, depending on certain details.