bluuebunny/crossref_metadata_2025 huggingface dataset:
Electrical-prospecting method for hydrocarbon search using the induced-polarization effect
Authors: Davydycheva Sofia , Rykhlinski Nikolai , Legeido Peter
Published: August 2006

We propose a method of surface and marine electrical prospecting using controlled-source excitation. The method is designed to detect hydrocarbon deposits at depths of a few kilometers and to map their boundaries. The technique is based on imaging the induced-polarization (IP) parameters of the geologic formation. We use the fact that, because of the imaginary part of the electric conductivity, polarized media support wave propagation processes whose nature is similar to displacement currents induced by the dielectric permittivity. However, unlike displacement currents, these processes reveal themselves at much lower frequencies and, therefore, at greater depths. It is established that the ratio of the second and the first differences of the electric potential does not decay after the current turn-off in polarized media, whereas it decays quickly if the IP effect is absent. Thus, the IP response can be observed directly and separated from the electromagnetic (EM) response. We use a vertical focusing of the electric current to decrease the effect of laterally adjacent formations to apply a 1D layered model in a 3D environment. This method obtained promising results in several regions of Russia.
Effects of an off-centered tool on dipole and quadrupole logging
Authors: Byun Joongmoo , Nafi Toksöz M.
Published: August 2006

An acoustic logging tool in inclined or horizontal boreholes may be placed apart from the center and produce additional complicated wavefields. We investigate the effects of an off-centered tool on monopole, dipole, and quadrupole logs due to off-centering of the tool. In recent logging tools, monopole, dipole, and quadrupole logs can be obtained by adding or subtracting responses at four monopole (pressure) receiver arrays at right angles. We examine the responses of the four monopole receiver array system for three directions of eccentricity: inline direction of the dipole source (Off [Formula: see text] case), crossline direction (Off [Formula: see text] case), and [Formula: see text] to the dipole source (Off [Formula: see text] case). To simulate responses at each receiver array, we use the discrete wavenumber method. In a dipole tool positioned on the borehole axis, the inline receiver arrays have only the flexural wave while the cross receiver arrays have zero response. However, an off-centered dipole source produces nondipole modes as well as the dipole mode. For all cases with a dipole source, the dipole mode was enhanced by subtracting responses at one of the inline receiver arrays from those of the other receiver array, and we could extract the formation shear velocity. Similar to the dipole source, an off-centered quadrupole source introduces additional nonquadrupole modes. The quadrupole mode was enhanced by subtracting the sum of responses at receiver arrays below negative poles of a quadrupole source from the sum of responses at receiver arrays below positive poles for all cases. In addition, the formation shear velocity was obtained from the time semblance calculation.
Removing free-surface multiples from teleseismic transmission and constructed reflection responses using reciprocity and the inverse scattering series
Authors: Fan Chengliang , Pavlis Gary L. , Weglein Arthur B. , Nita Bogdan G.
Published: August 2006

We develop a new way to remove free-surface multiples from teleseismic P- transmission and constructed reflection responses. We consider two types of teleseismic waves with the presence of the free surface: One is the recorded waves under the real transmission geometry; the other is the constructed waves under a virtual reflection geometry. The theory presented is limited to 1D plane wave acoustic media, but this approximation is reasonable for the teleseismic P-wave problem resulting from the steep emergence angle of the wavefield. Using one-way wavefield reciprocity, we show how the teleseismic reflection responses can be reconstructed from the teleseismic transmission responses. We use the inverse scattering series to remove free-surface multiples from the original transmission data and from the reconstructed reflection response. We derive an alternative algorithm for reconstructing the reflection response from the transmission data that is obtained by taking the difference between the teleseismic transmission waves before and after free-surface multiple removal. Numerical tests with 1D acoustic layered earth models demonstrate the validity of the theory we develop. Noise test shows that the algorithm can work with S/N ratio as low as 5 compared to actual data with S/N ratio from 30 to 50. Testing with elastic synthetic data indicates that the acoustic algorithm is still effective for small incidence angles of typical teleseismic wavefields.
Using the inverse scattering series to predict the wavefield at depth and the transmitted wavefield without an assumption about the phase of the measured reflection data or back propagation in the overburden
Authors: Weglein A. B. , Nita B. G. , Innanen K. A. , Otnes E. , Shaw S. A. , Liu F. , Zhang H. , Ramírez A. C. , Zhang J. , Pavlis G. L. , Fan C.
Published: August 2006

The starting point for the derivation of a new set of approaches for predicting both the wavefield at depth in an unknown medium and transmission data from measured reflection data is the inverse scattering series. We present a selection of these maps that differ in order (i.e., linear or nonlinear), capability, and data requirements. They have their roots in the consideration of a data format known as the T-matrix and have direct applicability to the data construction techniques motivating this special issue. Of particular note, one of these, a construction of the wavefield at any depth (including the transmitted wavefield), order-by-order in the measured reflected wavefield, has an unusual set of capabilities (e.g., it does not involve an assumption regarding the minimum-phase nature of the data and is accomplished with processing in the simple reference medium only) and requirements (e.g., a suite of frequencies from surface data are required to compute a single frequency of the wavefield at depth when the subsurface is unknown). An alternative reflection-to-transmission data mapping (which does not require a knowledge of the wavelet, and in which the component of the unknown medium that is linear in the reflection data is used as a proxy for the component of the unknown medium that is linear in the transmission data) is also derivable from the inverse scattering series framework.
Experimental determination of bulk dielectric properties and porosity of porous asphalt and soils using GPR and a cyclic moisture variation technique
Authors: Lai W. L. , Tsang W. F. , Fang H. , Xiao D.
Published: August 2006

This paper describes a new method for determining porosities in two porous construction and geologic materials (asphalt and soil) by using ground-penetrating radar (GPR) over a wide range of controlled degrees of water saturation [Formula: see text]. We call this method a cyclic moisture variation technique (CMVT). Freshwater is used as an enhancer or a tracer to allow GPR to easily detect and differentiate amounts of water or other moisture in these materials. The CMVT is based on measuring the changes of real permittivity [Formula: see text] and [Formula: see text] in the test materials as they transition from partially saturated states to a fully saturated state via cycles of water permeation and dewatering. This method does not disturb the test materials, as do the methods associated with traditional laboratory testing on cored samples. It also tests a large mass of in situ material, compared with the small mass tested by the conventional or electromagnetic coaxial transmission line (EMCTL) method (also known as a dielectric cell) and the time-domain reflectometry (TDR) method. Porosity values of asphalt [Formula: see text] and of soils [Formula: see text] were determined by fitting the data into the complex refractive index model (CRIM). Dielectric hysteresis of both soils and asphalt also is observable during the tests and shows that the pathways of water-ingress and water-egress processes are not identical in the plot of [Formula: see text] versus degrees of water saturation [Formula: see text].
Seismic Retrofit Using Spring Damper Devices on High-Voltage Equipment Stands
Authors: Riley Michael , Stark Chemelle , Kempner Leon , Mueller Wendelin
Published: August 2006

The Bonneville Power Administration (BPA) operates a significant portion of the electrical high-voltage transmission grid in the Pacific Northwest. As part of a long-term seismic mitigation program, BPA sponsors research into ways to minimize the vulnerability of existing electrical substation equipment. Passive energy dissipation devices add supplemental damping to improve the dynamic response of structures to earthquakes. One such mechanism, a friction spring damping device, utilizes a primary and secondary set of self-centering ring springs installed around a single end-mount load shaft to reduce peak accelerations. The adaptation of this technology to seismically retrofit existing high-voltage substation equipment single-pedestal support stand is the subject of this paper. Dynamic properties were determined from force-displacement and vibration tests. Full-scale earthquake transient tests conducted on a support stand equipped with friction spring devices resulted in substantial reductions of the in-plane peak accelerations in comparison to tests performed without the friction spring devices.
Investigation into the Effects of Foundation Uplift on Simplified Seismic Design Procedures
Authors: Harden Chad , Hutchinson Tara , Moore Mark
Published: August 2006

Uplifting of and yielding below shallow foundations supporting rigid lateral force–resisting elements can provide additional nonlinearity into a system's overall force-deformation behavior. While this nonlinearity may be advantageous, potentially reducing seismic demands, displacement compatibility may result in overstress of lateral and/or gravity-resisting elements. Incorporating this balance of benefit versus consequence in structural design is one goal of performance-based earthquake engineering (PBEE). There are a variety of approaches in design codes for estimating seismic demands and incorporating “performance” as a design goal. Such methods generally account for the displacement of an equivalent SDOF system by reducing the design strength, however, not explicitly for the case of foundation uplift. To address this shortcoming, this paper investigates the relationship between the strength ratio R and the displacement ratio C1 using the beam on nonlinear Winkler foundation (BNWF) concept. Numerical models were constructed considering a range of soil-structure natural periods and a range of design R values. Nineteen ground motions with a broad range of characteristics are used to conduct nonlinear time-history analyses. Results from these simulations indicate that current suggestions for C1- R relations are highly unconservative when uplifting foundations are anticipated. Revised C1- R relations for uplifting foundations are presented and an example numerical comparison provided.
Real-Time Seismic Monitoring of the New Cape Girardeau Bridge and Preliminary Analyses of Recorded Data: An Overview
Authors: Çelebi Mehmet
Published: August 2006

This paper introduces the state-of-the-art seismic monitoring system implemented for the 1,206-m-long (3,956 ft) cable-stayed Bill Emerson Memorial Bridge in Cape Girardeau (Missouri), a new Mississippi River crossing, approximately 80 km from the epicentral region of the 1811 and 1812 New Madrid earthquakes. The real-time seismic monitoring system for the bridge includes a broadband network consisting of superstructure and free-field arrays and comprises a total of 84 channels of accelerometers deployed on the superstructure (towers and deck), pier foundations (caisson tops and bents), and in the vicinity of the bridge (e.g., free-field, both surface and downhole). The paper also introduces the high-quality response data obtained from the broadband network that otherwise would not have been possible with older instruments. Such data is aimed to be used by the owner, researchers, and engineers to (1) assess the performance of the bridge, (2) check design parameters, including the comparison of dynamic characteristics with actual response, and (3) better design future similar bridges. Preliminary spectral analyses of low-amplitude ambient vibration data and that from a small earthquake reveal specific response characteristics of this new bridge and the free-field in its proximity. There is coherent tower-cable-deck interaction that sometimes results in amplified ambient motions. Also, while the motions at the lowest (triaxial) downhole accelerometers on both Missouri and Illinois sides are practically free from any feedback of motions of the bridge, the motions at the middle downhole and surface accelerometers are influenced significantly even by amplified ambient motions of the bridge.
Implementation of Inelastic Displacement Patterns in Direct Displacement-Based Design of Continuous Bridge Structures
Authors: Dwairi Hazim , Kowalsky Mervyn
Published: August 2006

Through the use of nonlinear time-history analysis, the displacement patterns of bridges subjected to transverse seismic attack are investigated. The variables considered in the study consist of bridge geometry, superstructure stiffness, substructure strength and stiffness, abutment support conditions, and earthquake ground motion. A series of three inelastic displacement pattern scenarios were identified: (1) rigid body translation (2) rigid body translation with rotation, and (3) flexible pattern. A relative stiffness index that is a function of the superstructure and substructure stiffness was shown to be a key variable in determining the type of displacement pattern a bridge is likely to follow. The results described in this paper have significant implications for performance-based seismic design procedures such as direct displacement-based design (DDBD). If the displacement pattern for a bridge can be identified with significant confidence at the start of the design process, application of approaches such as DDBD can be simplified. However, if the characteristics of the bridge are such that prescribing a pattern at the start of the process is not feasible, then an alternative approach must be employed for DDBD to proceed. Of the three displacement pattern scenarios defined in this paper, the first two require minimal effort in the design. For the third scenario, an iterative algorithm is proposed. Lastly, as a means for verification and demonstration, a series of bridges with various configurations was designed using DDBD for rigid body translation and flexible pattern scenarios. The designs for the flexible scenario showed good agreement with selected target profiles for bridges with up to five spans.
Phase II Trial of Capecitabine and Weekly Paclitaxel As First-Line Therapy for Metastatic Breast Cancer
Authors: Blum Joanne L. , Dees E. Claire , Chacko Aparna , Doane Lisa , Ethirajan Sukumar , Hopkins Judith , McMahon Richard , Merten Suzan , Negron Angel , Neubauer Marcus , Ilegbodu Des , Boehm Kristi A. , Asmar Lina , O'Shaughnessy Joyce A.
Published: August 2006

Purpose

The taxanes and capecitabine have synergistic antitumor activity in preclinical models. This trial was designed to determine the efficacy and tolerability of weekly paclitaxel plus capecitabine as first-line treatment for metastatic breast cancer (MBC).

Patients and Methods

Participants had histologically proven breast cancer, with measurable metastatic disease by Response Evaluation Criteria in Solid Tumors Group. Exclusion criteria included prior taxane therapy or any prior capecitabine or infusional fluorouracil. Participants received capecitabine 825 mg/m2/dose orally bid (1,650 mg/m2/d) for days 1 to 14. Paclitaxel 80 mg/m2 was administered intravenously weekly on days 1 and 8. Cycles were repeated every 3 weeks. Responders (complete or partial) or those with stable disease were treated until progression of disease or intolerable toxicity.

Results

Fifty-five women were enrolled; 94% received study therapy as first-line treatment for MBC. In the intent-to-treat population, objective responses (partial) were achieved in 30 patients (55%; 95% CI, 40% to 69%), and six additional patients had stable disease for 6 months or longer (clinical benefit rate of 65%). The median duration of response was 10 months (range, 2.5 to 18.7 months). Dose modifications and reductions were common, particularly for capecitabine, leading to a delivered dose-intensity of 75% for capecitabine and 91% for paclitaxel. The most frequent grade 3 to 4 treatment-related adverse events were hand-foot skin reaction (n = 10); neutropenia (n = 7); fatigue (n = 4); and leukopenia, diarrhea, and pain (n = 3 each).

Conclusion

Capecitabine in combination with weekly paclitaxel is an active and tolerable regimen as first-line therapy for women with MBC.
Development of Neuropathy in Patients With Myeloma Treated With Thalidomide: Patterns of Occurrence and the Role of Electrophysiologic Monitoring
Authors: Mileshkin Linda , Stark Richard , Day Bruce , Seymour John F. , Zeldis Jerome B. , Prince H. Miles
Published: August 2006

Purpose

Peripheral neuropathy frequently limits the duration of treatment with thalidomide for patients with multiple myeloma. We assessed the time course of occurrence, possible predictive factors, and the utility of serial nerve electrophysiological studies (NES) for detecting onset of neuropathy.

Patients and Methods

Seventy-five patients with relapsed/refractory myeloma were enrolled onto a multicenter trial of dose-escalating thalidomide with or without interferon. Patients underwent clinical assessment plus NES at baseline and every 3 months. Time to development of neuropathy according to clinical or NES criteria was compared. Patient and treatment-related factors were compared as predictors of neuropathy.

Results

Thirty-nine percent had some NES abnormalities at baseline. Patients received thalidomide at a median dose-intensity of 373 mg/d. Thirty-one of 75 patients (41%) developed neuropathy during thalidomide treatment; 11 patients (15%) discontinued treatment with thalidomide due to neuropathy. The actuarial incidence of neuropathy increased from 38% at 6 months to 73% at 12 months, with 81% of responding patients developing this complication. Serial NES did not reliably predict the imminent development of clinical neuropathy requiring thalidomide cessation, nor were patient age, sex, or prior therapy predictive. Patients who developed neuropathy had a longer duration of thalidomide exposure (median, 268 v 89 days; P = .0001). Cumulative dose or dose-intensity received was not predictive.

Conclusion

The majority of patients will develop peripheral neuropathy given sufficient length of treatment with thalidomide. To minimize the risk of neurotoxicity, therapy should be limited to less than 6 months. Electrophysiologic monitoring provides no clear benefit versus careful clinical evaluation for the development of clinically significant neuropathy.
Reduced Bone Mineral Density and Increased Bone Metabolism Rate in Young Adult Patients with 21-Hydroxylase Deficiency
Authors: Sciannamblo Mariateresa , Russo Gianni , Cuccato Debora , Chiumello Giuseppe , Mora Stefano
Published: August 2006

Context: Patients with congenital adrenal hyperplasia (CAH) receive glucocorticoids as replacement therapy. Glucocorticoid therapy is the most frequent cause of drug-induced osteoporosis.

Objective: The objective of the study was to evaluate bone mineral density (BMD) and bone metabolism in CAH patients.

Design: This was a cross-sectional observational study.

Setting: The study was conducted at a referral center for pediatric endocrinology.

Patients and Other Participants: Thirty young patients with the classical form of CAH (aged 16.4–29.7 yr) treated with glucocorticoid from diagnosis (duration of treatment 16.4–29.5 yr) and 138 healthy controls (aged 16.0–30.0 yr) were enrolled.

Main Outcome Measures: BMD was measured in the lumbar spine and whole body by dual-energy x-ray absorptiometry. Bone formation and resorption rates were estimated by serum measurements of bone-specific alkaline phosphatase and C-terminal telopeptide of type I collagen, respectively.

Results: CAH patients were shorter than controls (women −6.8 and men −13.3 cm). Therefore, several methods were used to account for the effect of this difference on bone measurements. Whole-body BMD measurements were significantly lower, compared with controls (P < 0.03), after controlling for height (on average −2.5% in females and −9.3% in male patients). No differences were found in lumbar spine measurements. Bone-specific alkaline phosphatase and C-terminal telopeptide of type I collagen serum concentrations were higher in CAH patients than control subjects (P < 0.04). BMD measurements and bone metabolism markers did not correlate with the actual glucocorticoid dose or mean dose over the previous 7 yr.

Conclusions: Young adult patients with the classical form of CAH have decreased bone density values, compared with healthy controls. This may put them at risk of developing osteoporosis early in life.
Adiponectin in Childhood and Adolescent Obesity and Its Association with Inflammatory Markers and Components of the Metabolic Syndrome
Authors: Winer Jeffrey C. , Zern Tosca L. , Taksali Sara E. , Dziura James , Cali Anna M. G. , Wollschlager Margaret , Seyal Aisha A. , Weiss Ram , Burgert Tania S. , Caprio Sonia
Published: August 2006

Context: Adiponectin levels are lower in obese children and adolescents, whereas markers of inflammation and proinflammatory cytokines are higher. Hypoadiponectinemia may contribute to the low-grade systemic chronic inflammatory state associated with childhood obesity.

Objective: We investigated whether C-reactive protein (CRP), the prototype of inflammation, is related to adiponectin levels independently of insulin resistance and adiposity.

Design, Setting, Participants, and Main Outcome Measures: In a multiethnic cohort of 589 obese children and adolescents, we administered a standard oral glucose tolerance test and obtained baseline measurements for adiponectin, plasma lipid profile, CRP, IL-6, and leptin.

Results: Stratifying the cohort into quartiles of adiponectin levels and adjusting for potential confounding variables, such as age, gender, ethnicity, body mass index z-score, pubertal status, and insulin sensitivity, the present study revealed that low levels of adiponectin are associated not only with higher CRP levels, but also with components of the metabolic syndrome, such as low high-density lipoprotein cholesterol and a high triglyceride-to-high-density-lipoprotein ratio.

Conclusions: The link between adiponectin levels and a strong marker of inflammation, CRP, is independent of insulin resistance and adiposity in obese children and adolescents. Adiponectin may be one of the signals linking inflammation and obesity. Thus, adiponectin may function as a biomarker of the metabolic syndrome in childhood obesity.
Opposing Influences of Prenatal and Postnatal Growth on the Timing of Menarche
Authors: Tam Charmaine S. , de Zegher Francis , Garnett Sarah P. , Baur Louise A. , Cowell Christopher T.
Published: August 2006

Context and Objective: Menarche is a milestone of reproductive development, and its timing may be differentially influenced by the growth conditions before birth and those between birth and puberty. The present study explored the relationships among menarcheal timing and markers of prenatal and midchildhood growth in healthy Australian girls.

Setting, Design, and Patients: A total of 156 girls aged 8 yr from a birth cohort of full-term babies had height, weight, and waist circumference measured. One hundred three girls had dual x-ray absorptiometry performed and blood analyzed for insulin, leptin, IGF-I, estradiol, and dehydroepiandrosterone sulfate levels. Girls were followed up at age 15 yr and their age of menarche was recorded.

Main Outcome Measures: Measures included age of menarche; birth weight and birth length; height, weight, waist circumference, and body composition by dual x-ray absorptiometry; and plasma insulin, leptin, IGF-I, estradiol, and dehydroepiandrosterone sulfate at age 8 yr.

Results: Girls with earlier menarche were light and long at birth and had higher total and central adiposity and IGF-I and estradiol levels in midchildhood, compared with those with later menarche. Age of menarche was best predicted by combining size at birth and body mass index z score at age 8 yr (r2 = 0.12; P < 0.001).

Conclusions: The timing of menarche appears to be influenced in opposing directions by pre- and postnatal growth. Menarche was found to occur earlier in girls who were long and light at birth and who had a higher fat mass and circulating IGF-I in childhood. These findings may partly explain ethnic differences and secular trends in the age of menarche.
Molecular basis of oocyte-paracrine signalling that promotes granulosa cell proliferation
Authors: Gilchrist Robert B. , Ritter Lesley J. , Myllymaa Samu , Kaivo-Oja Noora , Dragovic Rebecca A. , Hickey Theresa E. , Ritvos Olli , Mottershead David G.
Published: August 2006

Oocytes regulate follicle growth by secreting paracrine growth factors that act on neighbouring granulosa cells (GCs). Those factors identified to date are mainly members of the transforming growth factor-β (TGFβ) superfamily, but little is known about which specific receptor/signalling system(s) they employ. This study was conducted to determine the requisite pathways utilised by oocytes to promote GC proliferation. We used an established oocyte-secreted mitogen bioassay, where denuded mouse oocytes are co-cultured with mural GCs. Oocytes, growth differentiation factor-9 (GDF9), TGFβ1 and activin-A all promoted GC DNA synthesis, but bone-morphogenetic protein 6 (BMP6) did not. Subsequently, we tested the capacity of various TGFβ superfamily receptor ectodomains (ECD) to neutralise oocyte- or specific growth factor-stimulated GC proliferation. The BMP type-II receptor (BMPR-II) ECD antagonised oocyte and GDF9 bioactivity dose-dependently, but had no or minimal effect on TGFβ1 and activin-A bioactivity, demonstrating its specificity. The TGFβR-II, activinR-IIA and activinR-IIB ECDs all failed to neutralise oocyte- or GDF9-stimulated GC DNA synthesis, whereas they did antagonise the activity of their respective native ligands. An activin receptor-like kinase (ALK) 4/5/7 inhibitor, SB431542, also antagonised both oocyte and GDF9 bioactivity in a dose-dependent manner. Consistent with these findings, oocytes, GDF9 and TGFβ1 all activated SMAD2/3 reporter constructs in transfected GC, and led to phosphorylation of SMAD2 proteins in treated cells. Surprisingly, oocytes did not activate the SMAD1/5/8 pathway in transfected GCs although exogenous BMP6 did. This study indicates that oocyte paracrine factors primarily utilise a similar signalling pathway first identified for GDF9 that employs an unusual combination of TGFβ superfamily receptors, the BMPR-II and a SMAD2/3 stimulatory ALK (4, 5 or 7), for transmitting their mitogenic actions in GC. This cell-signalling pathway may also have relevance in the hypothalamic-pituitary axis and in germ-somatic cell interactions in the testis.
Preparation of NaA Zeolite Membrane with High Permeability by Using a Modified VPT Method
Authors: Cheng Zhi-Lin , Chao Zi-Sheng , Wan Hui-Lin
Published: August 2006

A novel method was developed for the preparation of NaA zeolite membrane with high quality. The method consisted of two stages, i.e., preseeding and secondary growth, and the two stages were both performed under the condition of vapor-phase transformation (VPT).
The Local Structure around Sodium Ions in Poly(ethylene-ran-methacrylic acid) Ionomers Studied by 23Na Solid-state NMR under a High Magnetic Field, 21.9 T
Authors: Yamamoto Yusuke , Murakami Miwa , Ikeda Ryuichi , Deguchi Kenzo , Tansho Masataka , Shimizu Tadashi
Published: August 2006

The local structure of sodium ions in poly(ethylene-ran-methacrylic acid) ionomer neutralized by sodium hydroxide has been investigated using 23Na MAS and multiple-quantum-magic-angle-spinning (MQMAS) NMR techniques at a high magnetic field. Isotropic chemical shifts and quadrupolar coupling products of three kinds of nonequivalent 23Na ions, i.e., isolated, hydrated, and aggregated 23Na ions were estimated from peak positions in 23Na MQMAS spectra. The MQMAS technique at high magnetic fields is expected to be a powerful tool to investigate the local structure in amorphous systems containing quadrupole nuclei.
Control of Stereoselectivity in 4-tert-Butylphenol Hydrogenation over a Carbon-supported Rhodium Catalyst by Carbon Dioxide Solvent
Authors: Hiyoshi Norihito , Mine Eiichi , Rode Chandrashekhar V , Sato Osamu , Ebina Takeo , Shirai Masayuki
Published: August 2006

cis-4-tert-Butylcyclohexanol was obtained with a high cis ratio (cis/(cis + trans) = 0.9) in the hydrogenation of 4-tert-butylphenol over a carbon-supported rhodium catalyst along with hydrochloric acid in supercritical carbon dioxide solvent.
Conditions on Single-walled Carbon Nanotubes for “Specific” Interactions with “Nonspecifically” Adsorbed Hemoglobin
Authors: Kato Ken , Sano Masahito
Published: August 2006

“Nonspecificity” is commonly observed in adsorption of proteins onto single-walled carbon nanotubes (SWCNTs). We show that, although any forms of SWCNT adsorb hemoglobin, only individually isolated, small diameter SWCNTs can induce specific responses of hemoglobin against a functional group attached to the SWCNTs.
Fe3O4-modified Carbon Nanotubes: A Facile and Efficient Method to Orientate Alignment in Magnetic Field
Authors: Shan Yan , Gao Lian
Published: August 2006

The orientation of carbon nanotubes (both SWNTs and MWNTs) has been demonstrated in magnetic field through modification with magnetic particles Fe3O4. The process of Fe3O4-modified CNTs composites is that acid-treated CNTs were refluxed in 2-pyrrolidone containing ferric triacetylacetonate at the solution’s boiling point with the protection of nitrogen gas. The composites are ideal materials to help the CNTs to be aligned in magnetic field.
Control of Anisotropic Tunnel Etching of Al by Indentation
Authors: Nishio Kazuyuki , Kanezawa Kenji , Masuda Hideki
Published: August 2006

Pitting sites on Al foil for electrolytic capacitors were controlled by the deformation of Al using a nanoindenter. During anodic etching of Al in hydrochloric acid solution, pitting was initiated at the edge of a triangular impression, and square pits were grown as a result of anisotropic dissolution of Al. Using this technique, 4 × 4 arrays of square pits were also obtained.
A Branch-and-Cut Procedure for the Multimode Resource-Constrained Project-Scheduling Problem
Authors: Zhu Guidong , Bard Jonathan F. , Yu Gang
Published: August 2006

This paper considers the multimode resource-constrained project-scheduling problem (MRCPSP) with a minimum-makespan objective. An exact branch and cut algorithm is presented based on the integer linear programming (ILP) formulation of the problem. In the preprocessing stage, lower bounds on the distance between each pair of precedence-constrained activities are derived. These bounds are used to reduce the number of variables in the model and to generate cuts that tighten the linear programming relaxation. The solution process is accelerated by an adaptive branching scheme in conjunction with a bound-tightening scheme that is called iteratively after branching. To find good feasible solutions in the early stages of the computations, a high-level neighborhood search strategy known as local branching is included. Here, a neighborhood of a feasible solution is defined by the linear inequalities in the ILP model and is searched first. As implemented, the full algorithm is exact rather than heuristic in nature. Numerical results are reported for 20- and 30-activity benchmark problems. These are the largest instances available and are generally viewed to be notoriously difficult. Up until now, there were no confirmed optimal solutions for any of the 552 30-activity instances. We were able to find several better solutions and to show that at least 506 are optimal.
Tonal Description of Polyphonic Audio for Music Content Processing
Authors: Gómez Emilia
Published: August 2006

We present a method to extract a description of the tonal aspects of music from polyphonic audio signals. We define this tonal description using different levels of abstraction, differentiating between low-level signal descriptors and high-level textual labels. We also establish different temporal scales for description, defining some features as being attached to a certain time instant, and other global descriptors as related to a wider segment. The description is validated by estimating the key of a piece. We also propose the description as a tonal representation of the polyphonic audio signal to measure tonal similarity between audio excerpts and to establish the tonal structure of a musical piece.
Methodologies for Evaluation of Note-Based Music-Retrieval Systems
Authors: Uitdenbogerd Alexandra L. , Chattaraj Abhijit , Zobel Justin
Published: August 2006

There have been many proposed music-retrieval systems, based on a variety of principles. How the effectiveness of these systems compares is not clear. The evaluation of some systems has been informal, without the rigor applied in other areas of information retrieval, and comparison of systems is difficult because of the lack of a common data set, queries, or relevance judgments. In this paper we explain how we collected artificial and expert music queries and name-based relevance judgments, and describe software we developed for collection of manual relevance judgments. Together with a collection of downloaded musical instrument digital interface (MIDI) files, these sets of queries and relevance judgments provide valuable tools for measuring music-retrieval systems. As an example of the value of these tools, we use them to compare the effect of using the expert queries and manual judgments to that of the artificial queries and manual judgments used in our earlier experiments.
Methylprednisolone-Induced Toxic Hepatitis
Authors: Topal Firdevs , Özaslan Ersan , Akbulut Sabiye , Küçükazman Metin , Yüksel Osman , Altiparmak Emin
Published: August 2006

Objective:

To report the third published case, as of April 8, 2006, of methylprednisolone-induced toxic hepatitis.

Case Summary:

A 47-year-old woman was admitted to our clinic with weakness, fatigue, pruritus, and scleral icterus that had developed 10 days prior to presentation. She had been taking topiramate for one year for treatment of chronic isolated central nervous system vasculitis. One week before her symptoms developed, she had completed a self-prescribed 7 day course of oral methylprednisolone for treatment of left arm weakness. She believed that methylprednisolone was appropriate since it had been used previously for acute episodes of vasculitis. Results of liver function tests performed on admission were alanine aminotransferase 2478 U/L, aspartate aminotransferase 1600 U/L, total bilirubin 10 mg/dL, direct bilirubin 8 mg/dL, alkaline phosphatase 138 U/L, and γ-glutamyl transferase 242 U/L. Topiramate and methylprednisolone were the only drugs she had been taking before admission, and no other causes of liver dysfunction (eg, infection, ischemia, systemic disease) were identified. Topiramate was stopped, and enzyme levels decreased to normal values within 45 days without treatment. There had been no increase in enzyme levels during hospitalization upon the accidental use of topiramate. Based on the history and laboratory findings, the final diagnosis was mixed hepatocellular and cholestatic liver injury caused by methylprednisolone.

Discussion:

Steroids have rarely been associated with hepatotoxicity; moreover, they are the treatment of choice for severe hepatitis. To date, only 2 cases of methylprednisolone-induced hepatotoxicity have previously been reported. Our case is similar to those with regard to mixed hepatocellular and cholestatic liver injury. Resolution of the hepatotoxicity occurred after discontinuation of the drug, with conservative treatment measures. An objective causality assessment based on the Naranjo scale suggests that hepatotoxicity was probably related to methylprednisolone.

Conclusions:

Although rare, hepatotoxicity related to methylprednisolone should be considered in patients who develop elevated enzyme levels while receiving this steroid.
Some Observations on Montmorillonite-Organic Complexes
Authors: Byrne P. J. S
Published: August 2006

Fifteen pure montmorillonites selected on the basis of minor differences in x-ray diffraction and differential thermal analysis data were treated with ethylene glycol, piperidine, and dodecylamine. X-ray and differential thermal data of the resulting complexes lead to the following conclusions:

(1) The complexes of montmorillonites with a given organic compound show differences ascribable to differences in the character of the montmorillonites. Attempts to relate variations in organic complexes to exchangeable cations, chemical composition, and collodial properties of the montmorillonites met with very limited success.

(2) All montmorillonites are mixed-layer sequences; i.e. adjacent layers differ from one another in composition, structure, or some other factor. It is suggested that mixed layering of this nature may also occur in other three-layer clay minerals.
Stability and Swell Pressure Characteristics of Compacted Clays
Authors: Seed H. B.
Published: August 2006

This paper discusses some of the factors affecting the density vs. stability relationships of compacted clays and some of the limitations of the concept that the stability of a compacted soil increases with an increase in density.

A series of tests performed on silty clay, in which stability was measured by triaxial compression tests, are described. It is shown that the relationship between density and stability of a soil depends on the criterion used to define stability; the greater the permissible strain before a sample is considered unstable, the greater is the possibility that an increase in density will cause an increase in stability. For the silty clay, when the stability is defined as the load required to cause 10 percent strain or less, an increase in density at a given water content caused an increase or decrease in stability depending upon the water content and the range of densities involved; at constant degrees of saturation, however, an increase in density always caused an increase in stability.

The effect of compaction method on the density vs. stability relationship is illustrated. Test data are presented for two soils, a silty clay and a sandy clay, comparing the stabilities, at various water contents and densities, of partially saturated samples compacted by impact methods, static pressure and kneading action. It is shown that, at equal water contents and densities, samples compacted by static pressures exhibit higher stabilities than samples compacted by impact or kneading methods; also, that the stabilities of samples at equal densities and water contents, compacted by impact and kneading methods, are very similar, with kneading compaction producing somewhat higher stabilities at lower degrees of saturation, and impact compaction producing slightly higher stabilities at higher degrees of saturation. For static compaction, both soils showed an increase of stability with increase in density at all water contents, while for samples compacted by impact and kneading methods, an increase in density at a given water content did not necessarily lead to an increase in stability.

The effect of saturation on the stability of compacted clays is shown and the influence of water content at compaction on the stability of saturated samples having the same density and water content is illustrated.

Finally, a comparison is made of the stability and swell pressures developed at various densities of samples of the sandy clay compacted by kneading action and static pressure and subsequently saturated by exudation of moisture from the samples under static loads. It is shown that very much higher swell pressures and stabilities are exhibited by the statically compacted samples than by the samples prepared by kneading action.
Shapes of Halloysite Particles in Japanese Clays
Authors: Sudo Toshio , Takahashi Hiroshi
Published: August 2006

Hydrated halloysite clays altered from glassy tuff during weathering were examined in detail by x-ray, thermal, and electron micrographic methods. The electron micrographs show fibrous crystals of hydrated halloysite associated with many rounded grains, the former frequently jutting out from the latter. X-ray powder diffraction data and thermal curves show clearly the presence of hydrated halloysite, and on closer examination dehydrated halloysite and a small amount of montmorillonite can be detected. The presence of allophane as an accessory mineral is suggested in certain specimens. Furthermore the degree of crystallinity of hydrated halloysite varies slightly from specimen to specimen. The variation of the degree of crystallinity of the hydrated halloysite and of the kinds and amounts of accessory clay minerals, and the variation of the shapes of the particles observed in the electron micrographs are generally related to each other. Hydrated halloysite of a relatively well-crystallized sort generally co-exists with halloysite (dehydrated) and consists of elongated crystals having sharp edges; rounded grains are composed entirely of these fibrous crystals. On the other hand, a poorly crystallized sort tends to be associated with allophane and to show extremely fine hairlike, twisted fibers; these are associated with well-defined rounded grains. A genetic process of clay-mineral formation from volcanic glass is considered.
Reactions of Molten Salts with Layer-Lattice Silicates
Authors: White Joe L.
Published: August 2006

A preliminary x-ray diffraction study of the effect of treatment of typical layer-lattice silicates with molten lithium, sodium, and potassium nitrates has been made. Treatment of Wyoming bentonite (Upton, Wyoming) with molten lithium nitrate produced random interstratification of spacings of 9.6 and 17.8 A when specimens were glycerol-solvated, with approximately 20 percent expanded layers. Treatment with sodium nitrate at 320° G produced a very high degree of preferred orientation in film specimens dried from water, whereas treatment with molten potassium nitrate produced a more random orientation in the specimen. The bentonite treated with molten sodium nitrate expanded completely to 17.8 A with glycerol; treatment with potassium nitrate resulted in a small amount of random interstratification, the proportion of expanded layers being about 80 percent.

Treatment of the <5μ fraction of Delamica (muscovite) with molten lithium nitrate removed a large portion of the potassium from the mica, and lithium was fixed in a not readily exchangeable manner. When barium-saturated and glycerol-solvated, the treated material gave an 001 spacing of 17.8 A, the basal spacing for glycerol-montmorillonoids. The amount of potassium removed from the muscovite varied with the muscovite/lithium-nitrate ratio and length of treatment.
Summary of Clay-Mineral Studies in Germany, 1954 and 1955
Authors: Hofmann Ulrich
Published: August 2006

Correns and Lippmann have extended the work carried out in England on swelling chlorites by some investigations on Keuper clays.

Dietzel has succeeded in showing that the infrared absorption band of kaolinite at 2.7 μ has two peaks which can be correlated with two different kinds of (OH) groups in the structure.

The “fire-clay” type of clay mineral has been found in Grossalmeroder clay by Lippmann and in Frantex clay from Provins by von Engelhardt. In Frantex clay especially the layer sequence is highly disordered. Halloysite is distinguished from these minerals by its greater layer spacing and metahalloysite by its tubular morphology.

Winkler has studied the particle size distribution of numerous brick clays and has established that the mineral must have a certain proportion of fine and coarse clay and fine sand, but also a very smooth particle size distribution curve from the finest to the coarsest particles if the clay is to be suitable for thin-walled ware.

The clay mineral section of the Deutsche Keramische Gesellschaft tested various methods for quantitative clay mineral analysis. More than 20 laboratories used the following methods: x-ray analysis, dilatometer analysis, D.T.A., dehydration curves, microscopic analysis, and the determination of free silica by solution in phosphoric acid.

By the investigation of mixtures made up of the purest quartz, feldspar, halloysite, illite, kaolinite, montmorillonite and “fire-clay” mineral, the correct values were found for the most part within a few percent.

In the investigation of natural clays, greater differences were found, amounting to as much as 10 percent. Von Engelhardt especially investigated the errors arising with Geiger counter x-ray equipment.
Intracrystalline Swelling, Cation Exchange, and Anion Exchange of Minerals of the Montmoril-Lonite Group and of Kaolinite
Authors: Hofmann Ulrich , Weiss Armin , Koch G. , Mehler A. , Scholz A.
Published: August 2006

The structural formulas were determined of very pure specimens of montmorillonite, bei-dellite, saponite, nontronite, hectorite, wolchonskoite, vermiculite, and batavite. The lattice perfection of these minerals and the nature and variation of their crystalline swelling depend significantly on the surface density of the exchangeable cations between the silicate sheets.

In a neutral solution of NH4F, OH ions were replaced by F ions. The exchange capacity is smaller the greater the diameter of the silicate layers of the various montmorillonite minerals. Since the anion-exchange capacity of nontronite can be increased through oxidation of Fe2 it is probable that the exchangeable OH ions are located on the boundaries of the octahedral layers.

With kaolinite, the cation-exchange capacity decreases with increasing thickness of the crystal plates. The OH ions of the basal surface can be exchanged with F ions, which leads to the destruction of the lattice.

A one-dimensional Fourier synthesis of K-batavite, like the investigations of Walker on vermiculite and of Brown and also Méring on montmorillonite, provides confirmation of the structure and enables the lattice positions of the K ions to be determined.
Regularly Interstratified Montmorillonite-Chlorite in Basalt
Authors: Earley J. W. , Milne I. H.
Published: August 2006

The dominant clay mineral in an amygdaloidal basalt from Mozambique is a mixed-layer variety having a highly regular alternation of montmorillonite-like and chlorite-like layers. The montmorillonite-chlorite occurs in the amygdules as green rosettes having a fine fibrous structure.

X-ray examination of this mineral shows a long spacing of about 29 A in air and a fairly well-developed sequence of basal spacings. The long spacing shows some variation which is dependent on the relative humidity of the air surrounding the sample. The montmorillonite-like layers expand with glycerol and contract with heat treatment similar to montmorillonite, while the chiorite-like layers show modified reflection intensities on heating similar to chlorite. The mineral shows a 31.7 A spacing when glycerol saturated and a 23.3 A spacing when fully dehydrated.