bluuebunny/crossref_metadata_2025_split huggingface dataset:
Risky Sexual Behaviors Among Hispanic Young Adults In South Florida: Nativity, Age at Immigration And Gender Differences
Authors: Weiss Ursula Keller , Tillman Kathryn Harker 
Published: December 2009

CONTEXT: U.S. Hispanics are disadvantaged compared with whites in regard to sexual health, particularly early sexual initiation and contraceptive use. It is unclear whether differences in nativity and immigration are associated with risky sexual behaviors. METHODS: Data collected between 1998 and 2000 from a community sample in South Florida were analyzed to examine sexual behaviors among 709 Hispanic individuals aged 18–23. Associations between nativity and age at immigration and sexual behaviors were assessed separately by gender using chi‐square tests and analyses of covariance. RESULTS: Smaller proportions of sexually experienced women who had immigrated to the United States before age six than of similar U.S.‐born women reported having had vaginal sex (83% vs. 91%) and oral sex (71% vs. 86%) in the past year. Compared with U.S.‐born women, those who had immigrated at age six or older reported lower levels of oral sex (66% vs. 86% of those with sexual experience) and drug use in conjunction with sex in the past year (mean score, 1.2 vs. 1.6 on a scale of 1–5), and a lower average lifetime number of sexual partners (2.0 vs. 3.7 in the sample overall). Immigrant men were no less likely than U.S.‐born men to engage in risky sexual behavior. CONCLUSIONS: Given the diversity of nativity and immigration histories among Hispanics in the United States, it is important that research examine both factors. An understanding of their joint association with sexual activity, plus the conditioning effects of gender, could help professionals to develop effective education and prevention programs for young people who are at risk for engaging in potentially dangerous sexual behavior.
A Little Thing Called Love: Condom Use in High‐Risk Primary Heterosexual Relationships
Authors: Corbett A. Michelle , Dickson‐Gómez Julia , Hilario Helena , Weeks Margaret R. 
Published: December 2009

CONTEXT:Condoms are less likely to be used in primary relationships than in other relationship types. An understanding of what women and men expect when entering into these relationships, as well as how they make decisions about condom use and other prevention behaviors, is essential to eff orts to curb the spread of HIV.METHODS:Qualitative in‐depth interviews were conducted with 25 high‐risk heterosexual couples, including HIV‐serodiscordant couples, participating in a trial of the female condom in Hartford in 2004–2007. Data were codedand analyzed in an iterative inductive and deductive process.RESULTS:Participants described nonuse of condoms as a strategy to fi nd and maintain a primary relationship, establish trust and increase intimacy. Many had unprotected intercourse while recognizing their risk of HIV and other STDs, placing their love for their partner and other emotional needs over concerns about their health. Several couples reduced their STD risk by practicing negotiated safety (i.e., using condoms until their serostatus had been determined) or similar strategies, including sharing sexual or drug use history, disclosing HIV test results and using condoms until they decided that their relationship would be monogamous.CONCLUSIONS:HIV prevention approaches must recognize the importance of love and the needs that primary relationships satisfy if they are to be considered relevant by those at greatest risk. Negotiated safety and similar strategies may be an important risk reduction tool for heterosexuals, particularly those in HIV‐aff ected relationships, but their potential eff ectiveness may vary.
Relationships Between Perceived STD‐Related Stigma, STD‐Related Shame and STD Screening Among a Household Sample of Adolescents
Authors: Cunningham Shayna D. , Kerrigan Deanna L. , Jennings Jacky M. , Ellen Jonathan M. 
Published: December 2009

CONTEXT: Important barriers to STD testing may include individuals' perceptions of STD‐related stigma (negative societal attitudes toward STD infection) and expectations of STD‐related shame (negative personal feelings) that would result from a positive STD test. Obtaining a clear understanding of the relationship between STD‐related stigma, STD‐related shame and STD testing may help inform programs and policies aimed at reducing STD transmission. METHODS: Measures derived from previously published scales were used to assess perceived STD‐related stigma, anticipated STD‐related shame and receipt of an STD test in the past year in an urban, household sample of 594 exually active 15–24‐year‐olds interviewed in 2004–2007. Logistic regression was used to examine associations between recent STD testing and perceived stigma, shame and other participant characteristics. RESULTS: Thirty‐seven percent of males and 70% of females reporting having had an STD test in the past year; the largest proportions of tests (42% among males and 59% among females) had occurred in the context of a routine health care visit, not because adolescents had had disease symptoms or were concerned about exposure to infection. For both males and females, the level of STD‐related stigma was negatively associated with the odds of having been tested (odds ratio, 0.5 for each). STD‐related shame was not related to STD testing. CONCLUSIONS: Adolescents who view STDs as stigmatizing have a reduced likelihood of being screened, but it is unclear whether this relationship refl ects their care seeking or providers' practice of off ering STD screening at a routine health visit.
Prospective Assessment of Pregnancy Intentions Using a Single‐ Versus a Multi‐Item Measure
Authors: Kavanaugh Megan L. , Schwarz Eleanor Bimla 
Published: December 2009

CONTEXT: Traditional measures of pregnancy intentions that are dichotomous and retrospective do not fully capture the complexity surrounding women's plans to become pregnant. METHODS: During January–June 2008, 249 women aged 15–44 awaiting pregnancy test results at family planning clinics in Pittsburgh completed a survey containing both single‐ and multi‐item measures of pregnancy intentions. Chi‐square analyses were used to assess differences between subgroups of women. RESULTS: Few women were trying to become or planning for pregnancy (11% on the single‐item measure; 20% on the multi‐item measure), while approximately one‐third of the sample were not trying to become or planning for pregnancy (31% on the single‐item and 36% on the multi‐item measure). The single‐item measure categorized more women as ambivalent about pregnancy (58%) than did the multi‐item measure (44%). Of women categorized as ambivalent by the single‐item measure, 62% were also categorized as ambivalent by the multi‐item measure. Overall, 68% of responses to the two measures were concordant. With both measures, women who were not planning or trying for pregnancy were more likely than those who were planning for pregnancy or who were ambivalent to indicate that they planned to have an abortion if their test was positive (27–29% vs. 0–2%). CONCLUSIONS: Prospective assessment of pregnancy intention with either a single‐ or a multi‐item measure may allow for a more nuanced assessment of pregnancy intention than current measures. The multi‐item measure may reduce the number of women categorized as ambivalent and aid the development of targeted contraceptive and preconception counseling interventions.
Determination of anionic groups in wood by time-of-flight secondary ion mass spectrometry and laser ablation-inductively coupled plasma-mass spectrometry
Authors: Tokareva Elena N. , Pranovich Andrey V. , Ek Paul , Holmbom Bjarne 
Published: December 2009

Abstract
A novel method for labelling of anionic groups on wood surfaces was developed and applied to spruce and aspen wood sections in the native state, and after acid washing and alkaline treatment. The metal ions Mg2+, Cu2+, Sr2+, and Zn2+ were used as markers and their patterns of attachment to anionic groups were assessed by time-of-flight secondary ion mass spectrometry (ToF-SIMS). Sr2+ was found to be a very suitable marker for labelling of anionic groups. In addition to ToF-SIMS, laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used for semi-quantitative analysis of labelled anionic groups in wood samples. ToF-SIMS imaging of Sr2+-labelled anionic groups revealed abundant anionic groups in bordered pit tori and ray parenchyma cell walls in spruce wood. LA-ICP-MS revealed that the relative concentration of Sr2+ in tori of bordered pits was approximately eight-fold higher than in fibre cell walls. After alkaline treatment the concentration of anionic groups in the fibre cell wall was approximately three-fold higher than in the original acid-washed spruce. In aspen wood, anionic groups were located mainly in pits between vessels and contact ray parenchyma cells, in ray cell walls and in certain fibre wall layers.
Analysis of products from the oxidation of technical lignins by oxygen and H3PMo12O40 in water and aqueous methanol by size-exclusion chromatography
Authors: Voitl Tobias , Nagel Marina V. , von Rohr Philipp Rudolf 
Published: December 2009

Abstract
One kraft lignin and two lignosulfonates were oxidized in aqueous acidic solutions containing a polyoxometalate (POM). The degradations were carried out in H2O or MeOH/H2O mixtures in the presence of oxygen. The treatment with aqueous H3PMo12O40 led to the dissolution of the studied lignins in the acidic medium (pH 1–2) and to the formation of up to 6.5 wt% vanillin and 6.2 wt% methyl vanillate based on the weight of dry lignin. The lignin oxidation products were analyzed by size-exclusion chromatography (SEC). For this purpose, a SEC method was developed, which allows the analysis of kraft lignin, lignosulfonates, and reaction products thereof without the need to remove the homogeneous catalyst. This method allows the direct observation of depolymerization and repolymerization reactions and hence the provision of a tool for studying the underlying chemistry. It has been demonstrated that the depolymerization of kraft lignin in water is accompanied by counterproductive condensation reactions. These repolymerization reactions were effectively prevented by addition of methanol, which couples competitively with lignin intermediates.
Hydrolysis of cellulose and wood powder treated with DMDHEU by a hydrolase enzyme complex, Fenton's reagent, and in a liquid culture of Trametes versicolor
Authors: Verma Pradeep , Mai Carsten 
Published: December 2009

AbstractCellulose was treated with various concentrations of 1,3-dimethylol-4,5-dihydroxyethylene urea (DMDHEU) to obtain different DMDHEU contents in the cellulose preparation. The release of sugars due to hydrolysis by a cellulase enzyme complex clearly decreased with increasing DMDHEU content. When the cellulose preparation with the highest DMDHEU content was subjected to pretreatment with Fenton's reagent (Fe2+, H2O2), the sugar release increased 4.5-fold. Incubation of modified cellulose with only H2O2did not increase sugar release by cellulase. Compared to cellulose, the sugar release from milled wood powder induced by cellulase was very low but still decreased due to treatment with DMDHEU. Sole incubation of wood powder with Fenton's reagent did barely cause more sugar release compared to the storage of wood powder in buffer, but when the pretreated wood was incubated with cellulase the sugar release was higher than without pretreatment. Release of sugar from untreated cellulose in liquid cultures of the white-rot fungusTrametes versicolorwas detected after 7 days and increased linearly with incubation time. Sugar release from DMDHEU-treated cellulose was much lower and was not detectable before 21 days of incubation. Total protein content in the cultures was low, but was slightly higher in the cultures of untreated cellulose. Laccase activity was not different in the presence of untreated and DMDHEU-treated cellulose after 7 and 14 days, but increased with increasing DMDHEU content after 21 and 28 days.
Effects of sample preparation on NIR spectroscopic estimation of chemical properties of Eucalyptus urophylla S.T. Blake wood
Authors: Gherardi Hein Paulo Ricardo , Lima José Tarcísio , Chaix Gilles 
Published: December 2009

AbstractMany studies have successfully applied near infrared (NIR) spectroscopy to estimate important wood traits. Some of them have reported the effects of wood surfaces on NIR spectra information and their influence on the performance of the predictive model. However, limited information is available concerning the effect of sample preparation on the model performance to estimate chemical properties inEucalyptuswood. Hence, the aim of this study was to investigate the influence of the milling procedure, particle size, and quality of the solid wood surface on the performance of the partial least squares regression to predict chemical properties ofEucalyptus urophyllawood by NIR spectroscopy. Adequate models were built to predict klason lignin content, acid-soluble lignin content, and syringyl-to-guaiacyl ratio inEucalyptus urophyllawood. Sample preparation strongly influences the ratio of performance to deviation (RPD) of these predictive models. The effect of the sample presentation (solid or milled wood) was stronger than the effect of the particle size difference between thin and thick powder. The best calibrations were developed using NIR spectra measured on wood powder (RDP values from 1.99 to 2.97), but satisfactory calibrations were developed from NIR spectra measured on solid samples (RPD values from 1.68 to 2.16).
Effects of timing and intensity of thinning on wood structure and chemistry in Norway spruce
Authors: Jyske Tuula , Kaakinen Seija , Nilsson Urban , Saranpää Pekka , Vapaavuori Elina 
Published: December 2009

AbstractThe effects of thinning intensity on wood structure and chemistry of Norway spruce [Picea abies(L.) Karst.] have been studied in a long-term thinning experiment established in the 1960s in south-western Sweden. The experiment comprised datasets of unthinned control trees and trees of four thinning treatments, in which thinning operations of different intensities were carried out. These thinning operations were applied either once, three, or five times over the course of the stand rotation. Thinning intensities varied from 0% to 60% based on the stand basal area (BA) before thinning: (A) 5×20% (i.e., 20% of the BA removed five times); (B) 3×40% (i.e., 40% of the BA removed three times); (C) 1×60% (i.e., 60% of the BA removed once); and (D) 5×40% (i.e., 40% of the BA removed five times). Altogether 60 trees that were 67 years old were sampled 38 years after the treatment onset. Radial growth rate, wood density, tracheid properties, and the chemical composition of wood were studied in detail. All four thinning treatments increased growth rate and decreased wood density; however, treatment D showed the greatest change. Single, heavy thinning in treatment C resulted in unfavourable intra-stem variation in ring width and wood density. No significant differences in tracheid properties and wood chemistry were found between the treatments. We conclude that only a remarkable increase in growth rate would induce detrimental changes in tracheid properties and wood chemistry in the context of thinning.
A Transparent Water-Based Polymer for Simulating Multiphase Flow
Authors: Lo Hung-Chieh (Jay) , Tabe Kazunori , Iskander Magued , Yoon Sung-Ho 
Published: December 2009

Abstract
This study proposes a new water-based transparent material called Aquabeads for modeling flow in natural soils. Three types of this material were used to model miscible and multiphase flow transport process in layered soil systems. An optical system was set up to trace flow movements in a two-dimensional (2D) physical model of a soil profile, analyzed using digital image processing to define images of 2D concentration profiles in the model. Model surfactant flushing tests were conducted using a layered soil system and two contaminants, mineral oil and motor oil, in order to illustrate the feasibility of using this water-based polymer to visualize geoenvironmental contamination problems. A surfactant solution made of Triton X-100 mixed with sec-butanol alcohol and xanthan gum was used to achieve a recovery ratio of 88.5 % of motor oil and 95.8 % of mineral oil. Because a transparent soil is used, the optical systems allows for visualizing surfactant flushing. Addition of xanthan gum to increase viscosity prevents mineral oil’s downward migration, thus significantly enhancing the oil recovery. The increase in viscosity of the surfactant prevents motor oil from bypassing the plume, thus enhancing recovery by up to 20 times. The study demonstrates that Aquabeads are suitable for modeling multiphase flow, particularly in educational settings.
A Simple Green Method for Biodiesel Iodine Number Determination
Authors: Aricetti Juliana Aparecida , Maciel Antonio José da Silva , Lopes Osvaldo Cândido , Tubino Matthieu 
Published: December 2009

Abstract
A simple and green method for the determination of the iodine number in biodiesel is proposed based on the Friedmann procedure for oils and fats adapted for biodiesel. The reagent solutions used are prepared in water with the exception of the standard iodine and the biodiesel solutions that are dissolved in ethanol 96 %. The method was compared with the procedure recommended by the norm EN 14111, which is essentially the Wijs method. Biodiesel derived from several oils and fats were analyzed using the two methods. A statistical comparison between them shows that both offer equivalent results and precision.
Capability Testing Based on Subsamples: A Case on Photolithography Process Control in Wafer Fabrication
Authors: Liao Mou-Yuan , Kang He-Yau , Lee Amy H. I. , Wu Chien-Wei 
Published: December 2009

Abstract
Photolithography is considered as the bottleneck in semiconductor manufacturing, and a good control of critical dimension, alignment accuracy, and photoresist thickness is essential for maintaining a high quality level of wafers. In this study, a photolithography process in a semiconductor factory is investigated, and the process performance of critical dimension, alignment accuracy, and photoresist thickness measurement is tested based on the process capability index CPMK. Critical values required for hypothesis testing are obtained based on subsamples. This investigation is useful to practitioners in making reliable decision in capability determination. By applying our research results to analyze the process performance with the three critical parameters, a production department can trace and improve the photolithography process.
Method for Measuring Thermal Conductivity of Small Highly Insulating Specimens
Authors: Miller Robert A. , Kuczmarski Maria A. 
Published: December 2009

Abstract
A hot plate method for the measurement of thermal conductivity is described, which is unique in that it combines all the following capabilities: (1) Measurements of very small specimens, (2) measurements of specimens with thermal conductivity on the same order of that as air, and (3) the ability to use air as a reference material. As with other approaches, care is taken to ensure that the heat flow through the test specimen is essentially one-dimensional. However, unlike other approaches, no attempt is made to use heated guards to minimize the flow of heat from the hot plate to the surroundings. Results indicate that since large correction factors must be applied to account for guard imperfections when specimen dimensions are small, simply measuring and correcting for heat from the heater disk that does not flow into the specimen may be preferable. Extensive computational heat transfer modeling and experimental measurements taken in a prototype apparatus show that this approach is feasible. Suggestions are made for further improvements based on analyses of the generated data.
A diminished thermal conductivity of Si/SiGe multilayers established through heating current frequency variation
Authors: Dooraghi Alex , Bandaru Prabhakar , Krommenhoek Dan , Elsner Norbert 
Published: December 2009

AbstractWe report on the measurement of the thermal conductivity of Si/Si0.8Ge0.2 multilayers on Si substrates through a variation of the 3? method. We exploit the frequency dependent variation of the thermal wave, through invoking the thermal penetration depth (TPD), which is inversely proportional to the frequency. Consequently, spectral measurements covering decades of frequency were used to finely probe the substrate and the overlying Si and Si0.8Ge0.2 thin film layers. Both in-phase and out-of phase measurements yielded comparable values of the thermal conductivity in the range of 3-5 W/mK, much lower than the reported bulk values. Our results provide proof of the potential of multilayered media to be used for reduced thermal conductance applications such as thermoelectrics, heat insulation etc.
Reduced-Order Models for Reservoir Simulation
Authors: Cardoso M. A. 
Published: December 2009

Abstract
The determination of optimal well settings is very demanding computationally, as the simulation model must be run many times during the course of the optimization. For this reason, reduced-order modeling procedures, which are a family of techniques that enable highly efficient simulations, may be very useful for optimization problems. In this paper we describe a recently developed reduced-order modeling technique which has been used in other application areas, the trajectory piecewise linear (TPWL) procedure, and incorporate it in production optimization computations. The TPWL methodology represents solutions encountered during the optimization runs in terms of Taylor series expansions around previously simulated states. This requires a small number of preprocessing (training) simulations using the full (high-fidelity) model, during which pressure and saturation states and Jacobian matrices are saved. These states and matrices are then projected into a low-dimensional space using proper orthogonal decomposition. Simulations in this reduced space can be performed very efficiently; in this work we observe runtime speedups of a factor of 1000. Overall speedups are, however, less due to the preprocessing overhead.
We assess the TPWL representation for simulations of waterflood in a heterogeneous 3D model containing 36,000 grid blocks and six wells. The high degree of accuracy of the TPWL model is first demonstrated for several testing simulations in which producer and injector well settings differ from those used in the training runs. The TPWL representations are then used in a computationally demanding multiobjective optimization problem, for which the Pareto front is determined. Limited high-fidelity simulations demonstrate the accuracy and applicability of TPWL for this optimization. Our overall conclusion is that the TPWL representation may be quite useful in production optimization problems.
Photovoltaic cells based on nickel phthalocyanine and zinc oxide formed by atomic layer deposition
Authors: Stakhira Pavlo , Pakhomov Georgij , Cherpak Vlad , Volynyuk Dmitro , Luka Grzegorz , Godlewski Marek , Guziewicz Elżbieta , Hotra Zenon 
Published: December 2009

Abstract
The introduction of an ultrathin zinc oxide (ZnO) layer formed by the atomic layer deposition (ALD) technique was found to improve the operation parameters of nickel phthalocyanine (NiPc) based photovoltaic cells with a transparent bottom electrode, indium tin oxide (ITO). This improvement is attributed to several reasons, such as I) increase of photovoltaic yield in ITO/p-NiPc/n-ZnO/Al cells incorporating a hybrid heterojunction as compared to single-layer ITO/NiPc/Al cells, II) enhancement of the overall spectral response in the double-layer cells and III) extension of long-term operational stability.