bluuebunny/crossref_metadata_2025 huggingface dataset:
Solvatochromism of Nile Red in Nonpolar Solvents
Authors: Yablon Dalia G. , Schilowitz Alan M.
Published: July 2004

The absorbance and fluorescence spectra of Nile Red (NR) were examined in a series of nonpolar solvents comprising linear alkanes and a range of poly alpha olefins (PAO). These solvents span a 1000-fold range in viscosity and possess very similar dielectric constants and refractive index properties. A high-energy double peak with vibronic structure is observed in both fluorescence and absorbance spectra, possibly indicating that a locally excited (LE) state is accessed in these solvents. In addition, a red shift in peak position is observed with increasing refractive index; however, it is unaccompanied by any changes in Stokes shift. This shift is attributed to changes in the high-frequency polarizability of the solvent, which is a function of the refractive index. Finally, an increase in quantum yield with viscosity is also observed.
Use of Infrared Spectroscopy for the Determination of Electronegativity of Rare Earth Elements
Authors: Frost Ray L. , Erickson Kristy L. , Weier Matt L. , McKinnon Adam R. , Williams Peter A. , Leverett Peter
Published: July 2004

Infrared spectroscopy has been used to study a series of synthetic agardite minerals. Four OH stretching bands are observed at around 3568, 3482, 3362, and 3296 cm−1. The first band is assigned to zeolitic, non-hydrogen-bonded water. The band at 3296 cm−1 is assigned to strongly hydrogen-bonded water with an H bond distance of 2.72 A. The water in agardites is better described as structured water and not as zeolitic water. Two bands at around 999 and 975 cm−1 are assigned to OH deformation modes. Two sets of AsO symmetric stretching vibrations were found and assigned to the vibrational modes of AsO4 and HAsO4 units. Linear relationships between positions of infrared bands associated with bonding to the OH units and the electronegativity of the rare earth elements were derived, with correlation coefficients >0.92. These linear functions were then used to calculate the electronegativity of Eu, for which a value of 1.1808 on the Pauling scale was found.
Detection of G-Quartet Structure in a DNA Aptamer Stationary Phase Using a Fluorescent Dye
Authors: Joyce Michelle Viglietta , McGown Linda B.
Published: July 2004

The fluorescent porphyrin dye N-methylmesoporphyrin IX (NMM) was used to provide direct evidence of intramolecular G-quartet formation by an oligonucleotide immobilized at the inner surface of a fused silica capillary. The oligonucleotide is the thrombin-binding DNA aptamer, which has been used in several analytical applications, including a stationary phase for open tubular capillary electrochromatography. Spectroscopic studies of the dye in batch solutions of the aptamer and of an oligonucleotide with the same base composition, but in a different, “scrambled” sequence that does not form an intramolecular G-quartet, provided evidence of selective fluorescence enhancement of NMM by the aptamer in the intramolecular G-quartet structure. On-column experiments compared results for injections of NMM onto an aptamer-coated capillary, a capillary coated with the scrambled sequence oligonucleotide, and a bare fused silica capillary. Results show that while NMM adsorbs to both coated capillaries, the selective fluorescence enhancement provides evidence of the intramolecular G-quartet structure on the aptamer-coated capillary.
Diode Laser Based Photoacoustic Water Vapor Detection System for Atmospheric Research
Authors: Szakáll Miklós , Bozóki Zoltán , Mohácsi Árpád , Varga Attila , Szabó Gábor
Published: July 2004

A wavelength modulated, distributed feedback diode laser based photoacoustic water vapor mixing ratio measuring system for atmospheric research applications is presented. Laser modulation parameters were optimized either at 180 or 500 mbar total pressure to enhance the system's sensitivity for low or high pressures (upper troposphere/lower stratosphere or biosphere exchange layer), respectively. A wavelength locking method was developed that ensured sub-picometer absolute (5 × 10−7 relative) wavelength stability of the laser while consuming minimum additional measurement time. At the calibration of the system, correction factors for the pressure- and temperature-dependence of the photoacoustic signal were determined, which were in turn applied to the calculation of the water vapor mixing ratio from the measured signal during the test operation of the system. The introduced features resulted in reliable, sub-ppm-level water vapor detection even under abrupt gas pressure or temperature variations typical in open atmospheric applications.
Maximum Likelihood Principal Components Regression on Wavelet-Compressed Data
Authors: Leger Marc N. , Wentzell Peter D.
Published: July 2004

Maximum likelihood principal component regression (MLPCR) is an errors-in-variables method used to accommodate measurement error information when building multivariate calibration models. A hindrance of MLPCR has been the substantial demand on computational resources sometimes made by the algorithm, especially for certain types of error structures. Operations on these large matrices are memory intensive and time consuming, especially when techniques such as cross-validation are used. This work describes the use of wavelet transforms (WT) as a data compression method for MLPCR. It is shown that the error covariance matrix in the wavelet and spectral domains are related through a two-dimensional WT. This allows the user to account for any effects of the wavelet transform on spectral and error structures. The wavelet transform can be applied to MLPCR when using either the full error covariance matrix or the smaller pooled error covariance matrix. Simulated and experimental near-infrared data sets are used to demonstrate the benefits of using wavelets with the MLPCR algorithm. In all cases, significant compression can be obtained while maintaining favorable predictive ability. Considerable time savings were also attained, with improvements ranging from a factor of 2 to a factor of 720. Using the WT-compressed data in MLPCR gave a reduction in prediction errors compared to using the raw data in MLPCR. An analogous reduction in prediction errors was not always seen when using PCR.
A Faster Approach to Infrared Rheo-Optics Using a Planar Array Infrared Spectrograph
Authors: Pellerin Christian , Frisk Simon , Rabolt John F. , Chase D. Bruce
Published: July 2004

Infrared rheo-optics combines dynamic mechanical analysis with infrared spectroscopy to provide molecular level information about the segmental reorientation and the changes in local environment associated with the dynamic deformation of polymers. Up to now, the application of this technique has been limited by the amount of time necessary to perform the experiments. In this article, we demonstrate that the use of a planar array infrared (PA-IR) spectrograph can accelerate the acquisition time by as much as two orders of magnitude while maintaining a signal-to-noise ratio (SNR) similar to that obtained using step-scan Fourier transform infrared (FT-IR) spectrometry, and by more than three orders of magnitude at the expense of a reduced SNR. The advantages and drawbacks of this new technique are discussed.
Microchip Laser-Induced Breakdown Spectroscopy: A Preliminary Feasibility Investigation
Authors: Gornushkin I. B. , Amponsah-Manager K. , Smith B. W. , Omenetto N. , Winefordner J. D.
Published: July 2004

A commercial, 7 μJ/pulse, 550 ps microchip laser is used to induce plasma on Pb, Si, Cu, Fe, Ni, Ti, Zn, Ta, and Mo foils and a Si wafer. The measured plasma lifetime is comparable with the duration of the laser pulse (a few ns). The plasma continuum radiation is low, while some of the strong resonance lines (e.g., Zn 213.86 nm) show self-reversal. Quantitative analysis is possible using non-gated detectors but analytical lines should be chosen with care to avoid reduction in the linear dynamic range. The mass removed (0.5–20 ng/pulse) is sufficient to yield spectra that are detectable with portable grating spectrometers equipped with non-gated, non-intensified detector arrays. The spectrum of Cd is detected with a broadband portable spectrometer (200–950 nm). The combination of the broadband spectrometer and the microchip laser is very promising for material identification, especially in field applications.
Dynamics of Inter-Korean Conflict and North Korea's Recent Policy Changes: An Inter-Systemic View
Authors: Koh Dae-Won
Published: July 2004

This study examines, from an inter-systemic perspective, North Korea's recent economic and foreign policy changes. It shows that despite North Korea's comparative failure, its leadership has neither been fully disillusioned about the feasibility of the system-maintaining alternative nor found a way to reform its system without breaking it down.
Income Inequalities under Economic Restructuring in Hong Kong
Authors: Xiaobin Zhao , Li Zhang , Kelvin Sit Tak O
Published: July 2004

Hong Kong's income inequalities have long been situated at a relatively high level by international standards. This paper investigates the factors that have contributed to this prolonged phenomenon. We argue that in the absence of appropriate government actions, economic progress in a laissez-faire capitalist system cannot necessarily equalize income distribution.
The Christian Invention of Judaism: The Theodosian Empire and the Rabbinic Refusal of Religion
Authors: BOYARIN DANIEL
Published: July 2004

ABSTRACT In this paper, it is argued that a significant development takes place in the second half of the fourth century and the beginning of the fifth, a development that we might call the orthodox Christian invention of religion. The paper examines effects of this development as it touches on Jewish religious historyas well.
Staphylococci isolated from animals and food with phenotypically reduced susceptibility to β-lactamase-resistant β-lactam antibiotics
Authors: Kaszanyitzky Éva J. , Egyed Zsuzsanna , Jánosi Sz. , Keserű Judit , Gál Zsuzsanna , Szabó I. , Veres Zoltán , Somogyi P.
Published: July 2004

The antibiotic resistance pattern of 1921Staphylococcusstrains isolated from animals and food within the last two years were examined using diffusion tests. Among them there were only 35 strains ofS. aureushaving an inhibition zone diameter of 15 mm or less, and 4 strains of coagulase-negative staphylococci (CNS) having a zone diameter of 18 mm or less to 1-µg oxacillin disk. These 39 strains were examined also by E-test to oxacillin and for the detection of themecAgene by PCR in order to determine whether they might be real methicillin-resistant staphylococci. Among the 39 strains there were only two that were susceptible to penicillin by disk diffusion method; however, further examination by the penicillinase test showed that they produced ß-lactamase. While 19 (15S. aureus,4 CNS) strains were resistant and 7 strains were intermediate to oxacillin in disk diffusion test, the E-test gave 8 resistant and 5 intermediate results. Six out of the 8 oxacillin-resistant strains examined by disk diffusion and E-test harboured themecAgene. Thus only 6 out of the examined 1921 strains proved to bemecApositive. These methicillin-resistant,mecA-positive strains (5 of theS. aureusstrains and 1 of theS. epidermidis) originated from two dairy herds. The results prove that methicillin-resistantS. aureus(MRSA) strains in animals are really rare in Hungary. Eighteen strains were chosen and screened for minimal inhibitory concentration (MIC) of oxacillin with or without clavulanic acid or sulbactam, and three of them produced methicillinase enzyme.
The incidence of mastitis treated with antibiotics in large-scale Hungarian Holstein-Friesian dairy farms
Authors: Kikkers B. H. , Ózsvári L. , Van Eerdenburg F. J. C. M. , Börzsönyi L. , Szenci O.
Published: July 2004

Treated mastitis episodes at large Hungarian dairy farms were studied to determine the distribution of mastitis treated with antibiotics among quarters of the udder. Data were detailed records of all mastitis episodes that occurred during 1976 lactations in Farm A infected withStaphylococcus aureus(from May 1995 through July 1998) and 808 lactations in Farm B free fromS. aureus(from January 1999 through March 2001). The distribution of treated quarters was compared with mathematical expectations based upon a random distribution in the case of Farm A. Results on mastitis incidences for different lactation stage groups showed an increasing incidence within subsequent lactation stage groups in Farm A. In contrast, in Farm B the mastitis incidence for lactation stage group between 35 and 100 days was the highest, but beyond 100 days the incidence decreased and reached the lowest value. Results gave strong evidence that the four quarters within the udder are not distributed randomly with respect to naturally occurring episodes of treated mastitis. More episodes than expected occurred in which only one or all four quarters were treated. Fewer episodes than expected with two or three treated quarters were observed. In both farms, the mastitis rate for rear quarters was higher than for front quarters, and the incidence of right quarter mastitis episodes was higher than that of left quarter mastitis episodes.
Mode‐selective stereomutation tunneling as compared to parity violation in hydrogen diselenide isotopomers 1,2,3H280Se2
Authors: Gottselig Michael , Quack Martin , Willeke Martin
Published: July 2004

We present quantitative calculations of the mode‐selective stereomutation tunneling in the chiral hydrogen diselenide isotopomers X2Se2 with X = H, D, and T. The torsional tunneling stereomutation dynamics were investigated with a quasi‐adiabatic channel quasi‐harmonic reaction path Hamiltonian approach, which treats the torsional motion anharmonically in detail and all remaining coordinates as harmonic (but anharmonically coupled to the reaction coordinate). We also investigated the influence of the excitation of fundamental modes on the stereomutation dynamics and predict which modes should be promoting or inhibiting. Our stereomutation dynamics results and the influence of parity violation on these are discussed in relation to our recent investigations for the analogous molecules H2O2, HSOH, H2S2, and Cl2S2. The electronic potential energy barrier heights for the torsional motion of hydrogen diselenide are similar to those of HSOH, whereas the torsional tunneling splittings are similar to the corresponding values of HSSH. The ground‐state torsional tunneling splittings calculated here for D2Se2 are of the same order as the parity‐violating energy difference reported by Laerdahl and Schwerdtfeger (Phys. Rev. A 1999, 60, 4439), whereas for T2Se2 the corresponding tunneling splitting is about three orders of magnitude smaller.
Relation between macroscopic and microscopic dielectric relaxation times in water dynamics
Authors: Arkhipov Vladimir I. , Agmon Noam , Arkhipov Vladimir I.
Published: July 2004

A simplified derivation for the ratio of macroscopic to microscopic relaxation times of polar liquids is based on the Mori‐Zwanzig projection‐operator technique, with added statistical assumptions. We obtain several useful forms for the lifetime ratio, which we apply to the dynamics of liquid water. Our theoretical single‐molecule relaxation times agree with the second Debye relaxation times as measured by frequency‐domain dielectric spectroscopy of water and alcohols. From the theory, fast relaxation modes couple to the Debye relaxation time, τd, through very large water clusters, and their temperature dependence is similar to that of τd. Slower modes are localized to smaller water clusters and exhibit weaker temperature dependence. This is exemplified by the lifetime ratios measured by time‐domain dielectric spectroscopy and optical Kerr effect spectroscopy, respectively.
Separating the photofragments of randomly oriented symmetric reactants by IR + UV laser pulses: Quantum simulations for FHF− → F + FH + e
Authors: Elghobashi Nadia , Manz Jörn
Published: July 2004

A linearly polarized intense few‐cycle infrared (IR) laser pulse causes dynamical symmetry‐breaking of symmetric ions or molecules, e.g., by stretching a selective bond, while compressing the equivalent other one. A well‐timed linearly polarized ultrashort ultraviolet (UV) pulse may then break the selected pre‐excited bond, e.g., the stretched one. The resulting product yield and directionality depend on the molecular orientation relative to the laser polarizations. As a consequence, the IR + UV laser pulses photodissociate preferentially the subset of well‐oriented reactants and drive their photofragments toward predetermined opposite directions, while leaving the other reactants unaffected. This approach to photodissociation and spatial separation of the fragments by IR + UV laser pulses is demonstrated by quantum simulations for the model system FHF‐ → F + FH + e.
Estimates of quantum chemical molecular characteristics for complete basis sets
Authors: Zahradník Rudolf , Šroubková Libuše
Published: July 2004

The large number of quantum chemical procedures and modifications thereof has for decades made difficult the comparison of results from various laboratories. In the realm of nonempirical calculations it has become possible to overcome the most serious source of errors (and simultaneously to contribute to unification of procedures), that is, the truncation of the one‐electron basis set, which concerns all levels ranging from the Hartree‐Fock (HF) to highly correlated levels. In this paper, extrapolations to a complete basis set (CBS) have been carried out by means of the simplest two‐parameter equation (Fi = F∞ + a/ni, where Fi is energy or another molecular characteristic resulting from a calculation with a basis set having ni one‐electron functions, F∞ is the sought‐after characteristic for CBS, and a is a constant). Besides total energies, also HF orbital energies (and related physical characteristics), features of molecular geometry, characteristics derived from the wave function (electric dipole and quadrupole moments), as well as vibrational characteristics acquired on the basis of the Wilson matrix analysis have been studied. Because of the main interest in properties of polyatomic systems, in addition to the coupled‐cluster method (CCSD(T)), systematic attention has been paid to less demanding techniques (HF, density functional theory (DFT), and Møsller‐Plesset second‐order correlation energy correction (MP2)) suitable not only for bigger systems but also for fitting constants of empirical potentials. Besides correlation‐consistent polarized‐valence basis sets (cc‐pVXZ, where X mostly assumes values from 2 through 5), augmented basis sets have been used also for selected systems. Altogether, 39 systems (molecules, ions, radicals, radical‐ions, van der Waals molecules, and an activated complex) have been investigated. In order to keep the length of this paper within reasonable bounds, only illustrative results are presented, with all other results available on request from the authors. As energy and energy changes have a special position among investigated quantities, it is appropriate to mention that linear plots of total energies carried out with simple and augmented basis sets have a common limit for 1/n = 0. The same is true for energy differences (δE) where, moreover, also δE with and without considering the basis set superposition error assumes the same or nearly the same common limit. The result is that a fair estimate of the CBS energy change can be based on mere simple basis set calculations for two sufficiently good basis sets, e.g., TZ and QZ. In the scope of this study, the experience with DZ basis set calculations is not satisfactory, and therefore these calculations should not be included in extrapolations.
One‐dimensional coordination polymers based on first‐row transition metals: A solid‐state study of weak backbone interactions
Authors: Russell Seidel S. , Tabellion Frank M. , Arif Atta M. , Stang Peter J.
Published: July 2004

We present further data on the solid‐state structures of one‐dimensional coordination polymers based upon dipositive transition metal hexafluoro‐acetylacetonate (hfacac) complexes. A variety of linking subunits are employed in order to investigate and probe the relatively weak interactions that make up the backbones of these polymers. Reported in this study are metal complexes containing manganese, zinc, copper, and cobalt and a range of donor building blocks encompassing an array of bonding motifs, including pyridyl—metal, pyridyl(N‐oxide)—metal, and hydrogen bonding. The specific linkers utilized are 4,4′‐dipyridyl N,N′‐dioxide hydrate, 2,5‐bis(4‐ethynylpyridyl)furan, 4,4′‐trimethylenedipyridine, and trans‐1‐(2‐pyridyl)‐2‐(4‐pyridyl)‐ethylene. A detailed discussion of the products is presented, as is a comparison to known compounds of a similar nature. All compounds are characterized via single‐crystal X‐ray diffraction and elemental analysis for the bulk of the sample.
A catalytic route to acyclic chiral building blocks: Applications of the catalytic asymmetric conjugate addition of organozinc reagents to cyclic enones
Authors: Jagt Richard B. C. , Imbos Rosalinde , Naasz Robert , Minnaard Adriaan J. , Feringa Ben L.
Published: July 2004

Through the Cu‐phosphoramidite‐catalyzed asymmetric conjugate addition a number of chiral cyclic enones are available with high ee. Here we report the sequential conjugate addition to these enones as a route towards multisubstituted chiral cyclic ketones. A subsequent Baeyer—Villiger oxidation followed by ring‐opening results in various linear synthons containing multiple stereocenters. This procedure represents a short, catalytic, and highly enantioselective route to a variety of acyclic chiral building blocks.
Reactivity studies of 2,3,5,6‐Tetra(2‐pyridyl) pyrazine (tppz) with first‐row transition metal ions
Authors: Campos‐Fernández Cristian S. , Smucker Bradley W. , Clérac Rodolphe , Dunbar Kim R.
Published: July 2004

Reactions of 2,3,5,6‐tetra(2‐pyridyl) pyrazine (tppz) with [ML6][X]2 (L = CH3CN, H2O;X = [BF4]−, [ClO4]−, [NO3]− [BArF]−(BArF ‐ B[3,5‐C6H3(CF3)2]4) lead to the high‐yield formation of mononuclear [M(tppz)2]2+, (M = MnII, FeII, CoII, and NiII) and dinuclear [Ni2(tppz)(CH3CN)6]4+ species. The new compounds were fully characterized by X‐ray crystallographic, spectroscopic, and magnetic susceptibility measurements. Surprisingly, the 2:1 M:tppz reactions did not lead to isolation of the dinuclear species except in the case of Ni(II). It was further noted that even in the case of the Ni reactions, the nuclearity of the product depends on the choice of anions and the reaction conditions. Magnetic measurements of the mononuclear species [Co(tppz)2]2+ revealed thermally induced spin‐crossover behavior from a high‐spin S = 3/2 at higher temperatures to a low‐spin S = 1/2 complex at lower temperatures. The dinuclear compound [Ni2(tppz)(CH3CN)6]4+ exhibits a weak anti‐ferromagnetic interaction through the bridging tppz ligand.
‘Undesirable’ and ‘desirable’ shifts in children's responses to repeated questions: age differences in the effect of providing a rationale for repetition
Authors: Howie Pauline , Sheehan Melanie , Mojarrad Tayebeh , Wrzesinska Monika
Published: July 2004

This study examined factors influencing children's tendency to shift responses when questions are repeated within an interview. Forty nine 4–5‐year‐olds and 40 7–8‐year‐olds were questioned about a video they had seen, with questions repeated by the same or a different interviewer. Half the children were given a rationale for question repetition, and half were not. Overall, the older children shifted less than the younger children, and, unlike the younger children, more to misleading than unbiased questions. The rationale did not affect overall shifting, but reduced the probability of ‘undesirable’ shifts (towards inaccuracy) in the younger children, and increased ‘desirable’ shifts (towards accuracy) at both ages. In the younger children, the rationale reduced total number of shifts, but only with the same interviewer, while in the older children the reverse applied. The results suggest developmental progression in the relative contributions of memorial and social/motivational factors to shifting. Implications for investigative interviewing with children are discussed. Copyright © 2004 John Wiley & Sons, Ltd.
The stirred tank reactor polymer electrolyte membrane fuel cell
Authors: Benziger Jay , Chia E. , Karnas E. , Moxley J. , Teuscher C. , Kevrekidis I. G.
Published: July 2004

The design and operation of a differential polymer electrolyte membrane (PEM) fuel cell is described. The fuel cell design is based on coupled stirred tank reactors (STRs) coupled through a membrane; the gas phase in each reactor compartment is well mixed. The characteristic times for reactant flow, gas phase diffusion, and reaction were chosen so that the gas compositions at both the anode and cathode are uniform. The STR PEM fuel cell is one‐dimensional; the only spatial gradients are transverse to the membrane. The cell is used to examine start‐up, and dynamic responses to changes in load, temperature, and reactant flow rates. Multiple time scales in the system's response are found to correspond to water absorption by the membrane, water transport through the membrane, and stress‐related mechanical changes of the membrane. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1889–1900, 2004
Prediction of the limit of the metastable zone in the “CaCO3CO2H2O” system
Authors: Elfil H. , Roques H.
Published: July 2004

The surpassing of the solubility product of the anhydrous forms of calcium carbonate—calcite, aragonite, and vaterite—is not sufficient to induce spontaneous precipitation. The existence of a metastable zone, in the nucleation of the calcium carbonate, is still an experimental phenomenon. A thermodynamic demarcation of the metastable zone in the “CaCO3CO2H2O” system, where only a secondary nucleation can occur, has been delimited for the first time. Through experimental exploration of a large supersaturation field, results obtained by the bubbling method are treated with the use of thermodynamic data of different varieties of CaCO3. At temperatures ranging between 25 and 60°C, a primary nucleation (spontaneous precipitation) occurs when the ionic activity product of the calco–carbonic solution surpasses the solubility product of CaCO3·H2O. No spontaneous nucleation occurs when the ionic activity product stabilizes between the solubility products of calcite and monohydrated calcium carbonate, which means that the solution remains in a metastable state. The metastability can be broken by seeding with calcium carbonate crystals (aragonite in this case) and then the germination is a secondary one. A model for the prediction of the limit of the metastable zone, presented in this report, is in agreement with experimental results. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1908–1916, 2004
Role of fine clays in bitumen extraction from oil sands
Authors: Liu Jianjun , Xu Zhenghe , Masliyah Jacob
Published: July 2004

Clay minerals such as montmorillonite and kaolinite are considered as fine solids that could adversely affect bitumen extraction from oil sands. Colloidal forces between bitumen and fine clays and between bitumen and bitumen in the presence of montmorillonite clays were measured with an atomic force microscope. Although long‐range repulsive forces between bitumen and kaolinite or montmorillonite were similar, stronger adhesion forces were measured between bitumen and montmorillonite than between bitumen and kaolinite, in particular when calcium ions were present. The presence of montmorillonite clays with calcium addition diminished the adhesive forces between bitumen surfaces. Zeta potential distributions of bitumen droplets and clays, individually or in a mixture, were measured in the presence of 1 mM calcium ions. The results showed that kaolinite clays deposited weakly on the bitumen surface, whereas montmorillonite clays attached strongly to bitumen. Such strong montmorillonite clay attachment set a barrier for bitumen droplets to coagulate with each other and to attach to air bubbles. This behavior accounts for the observed detrimental synergetic effect of montmorillonite clays and calcium ions on bitumen recovery by flotation. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1917–1927, 2004
Property integration: Componentless design techniques and visualization tools
Authors: El‐Halwagi Mahmoud M. , Glasgow Ian M. , Qin Xiaoyun , Eden Mario R.
Published: July 2004

Standard techniques for process design are based on tracking individual chemical species. Component material balances are at the heart of any design approach. Nonetheless, many design problems are not component dependent, but are driven by properties. Recently, the concept of clustering has been introduced to enable the conserved tracking of surrogate properties. Hence, the process design can be optimized, based on integrating properties instead of chemical species. Systematic techniques have been developed for this new paradigm of property integration to illustrate its applicability. Property integration is defined as a functionality‐based, holistic approach to the allocation and manipulation of streams and processing units, which is based on tracking, adjusting, assigning, and matching functionalities throughout the process. Revised lever arm rules are devised to allow optimal allocation while maintaining intra‐ and interstream conservation of the property‐based clusters. The property integration problem is mapped into the cluster domain. This dual problem is solved in terms of clusters and then mapped to the primal problem in the property domain. Several new rules are derived for graphical techniques. Particularly, systematic rules and visualization techniques for the identification of optimal mixing of streams and their allocation to units. Furthermore, a derivation of the correspondence between clustering arms and fractional contribution of streams is presented. This correspondence is employed to minimize the usage of fresh resources by minimizing cluster arms. The selection of optimal values of the augmented property index is also developed. Finally, graphical tools are devised for task identification of property adjustment. The new techniques are illustrated using a case study on fiber recovery in papermaking. © 2004 American Institute of Chemical Engineers AIChE J, 50: 1854–1869, 2004
Population and group structure of western lowland gorillas (Gorilla gorilla gorilla) at Lokoué, Republic of Congo
Authors: Gatti Sylvain , Levréro Florence , Ménard Nelly , Gautier‐Hion Annie
Published: July 2004

During a 17‐month study at the Lokoué clearing in Odzala National Park, Republic of Congo, we identified 377 western lowland gorillas. This population included 31 solitary males, 37 breeding groups, and eight nonbreeding groups. Its age‐ and sex‐class structure was similar to those observed at two other clearings in the same forest block. However, the size of breeding groups varied with site (either clearing or forest sites). At Lokoué, breeding groups (mean size: 8.2 gorillas; range: 3–15) included a single silverback male and, on average, 3.2 adult females. Nonbreeding groups (mean size: 5.5; range: 2–15) were devoid of adult females. Five of the nonbreeding groups were composed predominantly of blackbacks, subadult males, and juveniles, and thus fit the definition of all‐male groups previously observed in mountain gorillas. Our study confirms that 1) one‐male breeding groups are the norm in western gorillas, and 2) all‐male groups occur in this species. Despite frequent changes in members due to migrations of the males, the persistence of these all‐male groups indicates that they may play an important role in the life of migrating males. Variations in population structure, and group composition and type among gorilla populations are discussed. However, a further understanding of the evolution of group‐living in gorillas requires detailed ecological studies conducted in parallel with studies of the population structure and dynamics of these groups. Am. J. Primatol. 63:111–123, 2004. © 2004 Wiley‐Liss, Inc.
Ecological correlates of abundance in the Tana mangabey (Cercocebus galeritus)
Authors: Wieczkowski Julie
Published: July 2004

I investigated the ecological correlates of abundance in the Tana mangabey (Cercocebus galeritus), one of the world's most endangered primates, with the goal of recommending management strategies. I systematically selected 31 forest fragments throughout the mangabey's 60‐km distribution along the lower Tana River in southeastern Kenya. Within the 31 fragments, I measured vegetation structure, food abundance, and human forest product use in 107 belt transects, and conducted 370 mangabey surveys. I used a weighted multiple regression analysis to determine whether there was a dependence between the selected forest attributes and the mean number of mangabey groups per fragment. Fragment area and density of trees ≥10 cm diameter at breast height (DBH) were the only variables that significantly correlated with the variation in mangabey abundance. No additional variables were significant when the analysis was limited to forest fragments inside the Tana River Primate National Reserve (TRPNR) or to fragments outside the TRPNR. When I estimated the resources available before recent human forest product use by adding nonharvested and harvested variables, the total basal area of the top 15 food species became significant. This was only within the TRPNR, however. Management, therefore, should focus on increasing forest area, density of trees ≥10 cm DBH, and coverage of food trees throughout the mangabey's distribution. Solutions must be found for the problem of forest clearing, and forest product use must be better managed to protect the habitat of this critically endangered primate. The significance of food abundance only within the TRPNR suggests a need to collect dietary data from mangabey groups in fragments toward the southern limit of the mangabey's distribution, where plant species composition differs from that in fragments in which dietary data have been previously collected. Am. J. Primatol. 63:125–138, 2004. © 2004 Wiley‐Liss, Inc.
Nuclear integrations of mitochondrial DNA in gorillas
Authors: Jensen‐Seaman Michael I. , Sarmiento Esteban E. , Deinard Amos S. , Kidd Kenneth K.
Published: July 2004

Great ape systematics, particularly at the species level and below, is currently under debate, due in part to the recent influx of molecular data. The phylogenies of previously published mitochondrial control region (or D‐loop) DNA sequences in gorillas show deep splits within West African gorillas (Gorilla gorilla gorilla), and very high levels of nucleotide diversity in this subspecies. Here we demonstrate that several previously reported D‐loop haplotypes from West African gorillas are in all likelihood nuclear integrations of mitochondrial DNA. Revised estimates of the amount and pattern of mitochondrial DNA diversity in gorillas are provided, revealing two reciprocally monophyletic and highly divergent groups of gorillas, concurrent with their geographic distribution. Am. J. Primatol. 63:139–147, 2004. © 2004 Wiley‐Liss, Inc.
Evaluating the quality of research publications: A pilot study of school librarianship
Authors: Clyde Laurel A.
Published: July 2004

Evaluation of research quality is becoming more important in the field of library and information science, as in other fields. This pilot study is a preliminary attempt to address issues associated with determining the quality of the published research in one area of library and information science, specifically school librarianship. The main aims were (1) to test the extent to which experienced evaluators agreed in their rankings of published research articles on the basis of quality and (2) to investigate the approaches to evaluation used by the experienced evaluators. A qualitative, naturalistic research design was used. On the basis of a comprehensive literature review, four approaches to evaluation were identified; they were generally supported through an analysis of the responses of the experienced evaluators. However, although the majority of the evaluators agreed on the article ranked lowest, basic statistical analyses showed less agreement about the other articles. Although subject knowledge (of the field of school librarianship in this case) may have some influence on the evaluations, cluster analysis suggests that there may be differences in the value perceptions of the evaluators that also carry weight. More research would be needed to gain a better understanding of these value perceptions and their relationship, if any, to the four approaches to evaluation that were identified through the literature.
Are two document clusters better than one? The Cluster Performance Question for information retrieval
Authors: Losee Robert M. , Church, Jr. Lewis
Published: July 2004

When do information retrieval systems using two document clusters provide better retrieval performance than systems using no clustering? We answer this question for one set of assumptions and suggest how this may be studied with other assumptions. The “Cluster Hypothesis” asks an empirical question about the relationships between documents and user‐supplied relevance judgments, while the “Cluster Performance Question” proposed here focuses on the when and why of information retrieval or digital library performance for clustered and unclustered text databases. This may be generalized to study the relative performance of m versus n clusters.
The effects of the Children's Internet Protection Act (CIPA) in public libraries and its implications for research: A statistical, policy, and legal analysis
Authors: Jaeger Paul T. , Bertot John Carlo , McClure Charles R.
Published: July 2004

In upholding the Children's Internet Protection Act (CIPA), the U.S. Supreme Court has forced public libraries to face difficult issues about filtering Internet content. The implementation of filters creates a range of practical issues for libraries and also raises myriad research issues related to the effects of CIPA on public library services and on access to Internet‐based information in public libraries. Using a multimethod, iterative research strategy, this article explores selected areas related to filtering that may affect the provision of Internet content and services in public libraries. This study presents preliminary data about the impact of CIPA on public libraries and offers a perspective of what research is necessary to provide a better understanding of the impacts of CIPA and to determine what research would need to be conducted for potential future legal challenges to the application of CIPA in public libraries.
Engineering education in sustainable development: sustainability as a tool to open up the windows of engineering institutions
Authors: Mulder Karel
Published: July 2004

Engineering faces a crisis throughout Western society. The number of engineering students is dropping considerably. The prestige of technology and engineering has dropped simultaneously. In the 1950s, nobody doubted the role of technology as the engine of progress, but the demystification of technology in the 1970s focused around various controversies, like that of nuclear energy, and criticism gave rise to changes. However, mainstream engineering was generally not affected.

 Sustainability was initially regarded by many engineers as a new attack, as various accepted cleaning technologies (such as sewerage clearing or filtering) were often criticized as ‘end of pipe’. Gradually, the message that sustainable development (SD) is a challenge and not a burden for the engineering community has grown. Integrating SD cannot be achieved just by putting a social science course into an engineering curriculum: the cultural divide is too large to be bridged in this way. This article will analyse recent changes that have taken place in two technical universities, and will offer some guidelines for successful implementation of SD in engineering curricula. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Business, environmental reform and technological innovation in Hong Kong
Authors: Hills Peter , Lam Jacqueline , Welford Richard
Published: July 2004

Within a framework of ecological modernization theory this paper focuses on the process of environmental reform in Hong Kong. It argues that there is significant inertia within the environmental policy process in Hong Kong, but that with leadership from the business sector there exists the potential for positive change. We identify ways to further drive the process of environmental reform through an emphasis on the role of the business sector and technological innovation. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Stakeholders and environmental management practices: an institutional framework
Authors: Delmas Magali , Toffel Michael W.
Published: July 2004

Despite burgeoning research on companies' environmental strategies and environmental management practices, it remains unclear why some firms adopt environmental management practices beyond regulatory compliance. This paper leverages institutional theory by proposing that stakeholders – including governments, regulators, customers, competitors, community and environmental interest groups, and industry associations – impose coercive and normative pressures on firms. However, the way in which managers perceive and act upon these pressures at the plant level depends upon plant‐ and parent‐company‐specific factors, including their track record of environmental performance, the competitive position of the parent company and the organizational structure of the plant. Beyond providing a framework of how institutional pressures influence plants' environmental management practices, various measures are proposed to quantify institutional pressures, key plant‐level and parent‐company‐level characteristics and plant‐level environmental management practices. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Environmental upgrading of Third World enterprises through linkages to transnational corporations. Theoretical perspectives and preliminary evidence
Authors: Jeppesen Soeren , Hansen Michael W.
Published: July 2004

With economic globalization, Third World enterprises are increasingly collaborating with foreign firms through trade, subcontracting and equity linkages. The paper examines under which conditions linkages to foreign firms lead to environmental upgrading of Third World enterprises. Derived from the authors' research in a number of developing countries, the paper presents preliminary evidence of such upgrading. As the existing literature on environmental upgrading has a normative bias and tends to ignore economic mandates and constraints, the remaining part of the paper presents four theoretical frameworks based on standard business economics that may explain under which conditions linkages between Third World enterprises and foreign firms may be accompanied by environmental upgrading. It is argued that environmental upgrading in the value chain must be understood partly as a result of external industry and market forces, and partly as a result of the internal resources and competitive strategies of the companies involved. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Building innovations for sustainability: 11th international conference of the Greening of Industry Network
Authors: Hines Frances , Marin Otilia
Published: July 2004

This essay provides an overview of the 11th International Conference of the Greening of Industry Network held in San Francisco, USA, on 12–15 October 2003. The conference gave Greening of Industry Network (GIN) members the opportunity to debate issues around the theme of Innovating for Sustainability in a location central to technological innovation in the United States. This special issue of Business Strategy and the Environment focuses on the diverse interpretations of innovation and their impacts on the different strands of sustainability. The conference was timely in its debates about the nature of innovation from system level to product level, and from technological innovation to innovations in the management of a wide range of stakeholders and the resulting impacts on environmental, economic, social and ethical sustainability. This essay briefly discusses the relationship between innovation and sustainability, and considers the factors that either facilitate progress towards a more sustainable future, or present barriers to achieving sustainability. Copyright © 2004 John Wiley & Sons, Ltd and ERP Environment.
Bounds and normalization of the composite linkage disequilibrium coefficient
Authors: Zaykin Dmitri V.
Published: July 2004

The composite linkage disequilibrium (LD) measure is often calculated for two‐locus genotypic data, especially when coupling and repulsion double heterozygotes cannot be distinguished. This measure was reported to have good statistical properties and was suggested for routine testing of LD, regardless of Hardy‐Weinberg equilibrium at either of two loci (Weir [1979] Biometrics 35:235–254; Schaid [2004] Genetics 166:505–512). However, the bounds for this measure have not been yet reported. These bounds are derived here as functions of one‐locus genotype or allele frequencies. They provide standardized measures of composite linkage disequilibrium, defined as the proportion of its maximum attainable value, given observed allele or genotype frequencies. © 2004 Wiley‐Liss, Inc.
Energetic and topological analysis of the reaction of Mo and Mo2 with NH3, C2H2, and C2H4 molecules
Authors: Michelini Maria Del Carmen , Russo Nino , Alikhani Mohammad Esmaïl , Silvi Bernard
Published: July 2004

The Density functional theory has been applied to characterize the structural features of Mo1,2NH3,C2H4, and C2H2 compounds. Coordination modes, geometrical structures, and binding energies have been calculated for several spin multiplets. It has been shown that in contrast to the conserved spin cases (Mo1,2NH3), the interaction between Mo (or Mo2) and C2H4 (or C2H2) are the low‐spin (MoC2H4 and C2H2) and high‐spin (Mo2C2H4 and C2H2) complexes. In the ground state of Mo1,2C2H4 and C2H2, the metal‐center always reacts with the CC center. The spontaneous formation of the global minima is found to be possible due to the crossing between the potential energy surfaces (ground and excited states with respect to the metallic center). The bonding characterization has been performed using the topological analysis of the Electron Localization Function. It has been shown that the most stable electronic structure for a π‐acceptor ligand correlates with a maximum charge transfer from the metal center to the CC bond of the unsaturated hydrocarbons, resulting in the formation of two new basins located on the carbon atoms (away from hydrogen atoms) and the reduction of the number of attractors of the CC basin. The interaction between Mo1,2 and C2H4 (or C2H2) should be considered as a chemical reaction, which causes the multiplicity change. Contrarily, there is no charge transfer between Mo1,2 and NH3, and the partners are bound by an electrostatic interaction. © 2004 Wiley Periodicals, Inc. J Comput Chem 25: 1647–1655, 2004