bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis and NMR spectroscopic characterization of Si-substituted 1-silacyclobutene derivatives
Authors: Khan Ezzat , Wrackmeyer Bernd 
Published: November 2010

Abstract
Hydroboration of trialkyn-1-yl(organo)silanes with one equivalent and two equivalents of 9-borabicyclo[3.3.1]nonane, 9-BBN afford dialkyn-1-ylsilanes and alkyn-1-ylsilanes, respectively. The alkyn-1-ylsilane derivatives are stable at room temperature and can be store under dry argon for prolong period of time. These compounds are attractive materials for further rearrangements to afford novel 1-silacyclobutene derivatives bearing Si-alkenyl or Si-alkynyl functionalities. The hydroboration reaction is well controlled by the Si-R1 function, i.e., the starting silanes with R1 = Ph selectively afford hydroboration of one Si-C≡C bond with one equivalent of 9-BBN, leaving the other two functionalities untouched. Under mild reaction conditions (25°C), the starting silanes with R1 = Me lead to mixture containing dialkyn-1-ylsilane, alkyn-1-ylsilane and their respective 1-silacyclobutene derivatives. All new compounds are sensitive towards air and moisture and were studied by multinuclear magnetic resonance spectroscopy (1H, 13C, 11B, 29Si NMR) in solution.
Methylcellulose/SiO2 hybrids: sol-gel preparation and characterization by XRD, FTIR and AFM
Authors: Rangelova Nadezhda , Radev Lachezar , Nenkova Sanchi , Miranda Salvado Isabel , Vas Fernandes Maria , Herzog Michael 
Published: November 2010

Abstract
Methylcellulose (MC) / SiO2 organic / inorganic hybrid materials have been prepared from MC and methyltriethoxysilane or ethyltrimethoxysilane, and characterized by XRD, FTIR and AFM. XRD showed peak shifts. FTIR shows intermolecular hydrogen bonding between MC and SiO2. AFM depicts surface roughness which depends on the silica precursor and MC content.
Silver nanoparticles: synthesis through chemical methods in solution and biomedical applications
Authors: García-Barrasa Jorge , López-de-Luzuriaga José , Monge Miguel 
Published: November 2010

Abstract
Chemical methods provide an easy way to synthesize silver nanoparticles (Ag NPs) in solution. These metal nanoparticles have a great potential for biomedical applications as an antibacterial, antifungal, and antiviral agent or in wound healing. The adjustment of the parameters involved in these reactions permits a precise control over the size, shape, monodispersity, and the surfaces of the nanoparticles. These nanoparticles are being used in the design of new hybrid organic-inorganic or inorganic nanomaterials for biomedical applications.
Convection heat transfer in a Maxwell fluid at a non-isothermal surface
Authors: Vajravelu Kuppalapalle , Prasad Kerehalli , Sujatha Ashwatha 
Published: November 2010

Abstract
Analysis is carried out to study the convection heat transfer in an upper convected Maxwell fluid at a non-isothermal stretching surface. This is a generalization of the paper by Sadeghy et al. [21] to study the effects of free convection currents, variable thermal conductivity and the variable temperature at the stretching surface. Unlike in Sadeghy et al., here the governing nonlinear partial differential equations are coupled. These coupled equations are transformed in to a system of nonlinear ordinary differential equations and are solved numerically by a finite difference scheme (known as the Keller-Box method) and the numerical results are presented through graphs and tables for a wide range of governing parameters. The results obtained for the flow and heat transfer characteristics reveal many interesting behaviors that warrant further study of nonlinear convection heat transfer.
First-principles LCAO study of phonons in NiWO4
Authors: Kuzmin Alexei , Kalinko Aleksandr , Evarestov Robert 
Published: November 2010

Abstract
The electronic, structural and phonon properties of antiferromagnetic wolframite-type NiWO4 have been studied using first-principles spin-polarized LCAO calculations based on the hybrid Hartree-Fock (HF)/density functional (DFT) scheme. The influence of different percentages of HF contribution, i.e. different correlation strength, on the structure and phonon frequencies has been investigated and compared with the available experimental data.
Optical and electrical properties of nanocrystalline TiO2:Pd semiconducting oxides
Authors: Sieradzka Karolina , Kaczmarek Danuta , Domaradzki Jarosław , Prociów Eugeniusz , Mazur Michał , Górnicka Barbara 
Published: November 2010

Abstract
Electrical and optical properties of TiO2:Pd thin films deposited from Ti-Pd mosaic targets sputtered in reactive oxygen plasma have been studied. The properties were investigated for thin films with the Pd amount of 5.5 at. %, 8.4 at. % and 23 at. %. Based on resistivity measurements a drop from 103 down to almost 10−3Ωcm has been recorded when the Pd amount was varied from 5.5 at. % to 23 at. %, respectively. Moreover, it was shown that doping with different amounts of Pd results in the possibility of obtaining both types of electrical conduction: n-type for the TiO2 with 5.5 at. % and 8.4 at. % of Pd and p-type for the TiO2 with 23 at. % of Pd thin films. From optical measurements it has been found that as the Pd amount was increased the transmission through the thin films was reduced and position of the fundamental absorption edge was shifted toward a longer wavelength range of up to 600 nm. The optical band gap was calculated for direct and indirect transitions from optical absorption spectra. Structural properties were characterized by X-ray diffraction (XRD) and atomic force microscopy (AFM). The XRD patterns displayed occurrence of the crystalline, TiO2-rutile for lower Pd amounts (5.5 at. %, 8.4 at. %), while the TiO2:Pd (23 at. %) thin films displayed XRD-amorphous behaviour. Images obtained from AFM displayed dense, nanocrystalline structure with homogenous distribution of crystallites. Additionally performed secondary ion mass spectroscopy investigation confirmed homogenous distribution of Pd in the whole thickness of the prepared thin films.
Geodetic precession and frame dragging observed far from massive objects and close to a gyroscope
Authors: Trenčevski Kostadin , Celakoska Emilija 
Published: November 2010

Abstract
Total precession (geodetic precession and frame dragging) depends on the velocity of each source of gravitation, which means that it depends on the choice of the coordinate system. We consider the latter as an anomaly specifically in the Gravity Probe B experiment, we investigated it and solved this anomaly. Thus, we proved that if our present expression for the geodetic precession is correct, then the frame dragging should be 25% less than its predicted value.
Cyclic patterns of malaria incidence in Burundi
Authors: Dimitrov Borislav , Valev Dimitar , Werner Rolf , Atanassova Penka 
Published: November 2010

Abstract
Best available descriptions of malaria incidence and mortality dynamics are important to improve and evaluate the implementation of programs to monitor (e.g., remote sensing) and control disease, especially in endemic zones. High-frequency (e.g., semi-annual and seasonal) cycles in malaria incidence have been observed in various countries and they coincide with cycles in the natural environment (e.g., temperature, heliogeophysical activity, etc.). However, neither trend nor cyclical oscillations beyond a 6-month (0.5-year) period for this vector-borne disease were reported in a recent analysis on monthly notifications in Burundi for the years 1997–2003. Since the examination of graphical plots indicated an eventual existence of trans-year (multiannual) variations, we further analyzed the same data in more detail. Here we explore whether low-frequency cycles (beyond seasonality) might exist (e.g., trans-year cycles with periods of 13–24 months or longer). Monthly incidence rate per 100 inhabitants from the Province of Karuzi, Burundi, over the years 1997–2003 was analysed. The exploration of underlying chronomes (time structures) was done by linear and non-linear parametric regression models, autocorrelation, spectral analysis (e.g., fast Fourier transforms), periodogram regression analysis (PRA) and wavelet transform (WT). By using a periodogram regression analysis, we describe a multicomponent cyclic chronome with periods T>12 months (19 and 86 months, all at P<0.05). Notably, the strongest cyclic pattern in the periodogram of the detrended malaria rates (whereas the peak was suppressed and beyond the semi-annual cycle of 6 months) was ≈1.5–1.6 years (T=19.0 months, R=0.32). A dynamic pattern of “shortening” of the length (period) of the cycles was observed during the pre-epidemic interval (from 8–9 to 5–6 months and from 20–22 to 16–18 months in years 1997–2000) that can be used to anticipate a forthcoming incidence increase and epidemic levels of malaria at a regional level. Indeed, these cycles in malaria incidence correspond to cyclic components of heliogeophysical activity (HGA) such as the sunspot cycle impulses of 0.5–2.0 years as well as the quasi-biennial solar magnetic cycle of 1.5–2.5 years and further, detailed analyses are warranted to investigate such relationships. A multicomponent dynamic cyclical pattern of malaria incidence variations in Burundi (1997–2003) exists thus allowing further, more specific analyses and modelling as well as correlations with similar environmental cycles to be explored. These results might also contribute to better estimates for forecasting, prevention and understanding of malaria dynamics and aetiology.
Fast ferritin immunoassay on PDMS microchips
Authors: Schrott Walter , Nebyla Marek , Meisterová Lucie , Přibyl Michal 
Published: November 2010

AbstractA heterogeneous sandwich immunoassay of ferritin on a poly(dimethylsiloxane) microfluidic chip is proposed. An undemanding “prepolymerization technique” based on wet treatment of a phosphor bronze substrate was used for the microchip fabrication. Receptor rabbit antibodies were immobilized via passive sorption directly on microchannel walls. After the incubation of ferritin samples, secondary biotinylated antibodies were introduced. A solution of avidin molecules labeled by fluorescein isothiocyanate was finally added into the microchannels. Lamp-based fluorescence detection of the immunocomplex was then carried out. Dynamic detection range of the method was in the interval from 100 ng mL−1 to 10 μg mL−1.
Effect of fiber modification with carboxymethyl cellulose on the efficiency of a microparticle flocculation system
Authors: Ondaral Sedat , Kurtuluş Orçuun , Usta Mustafa 
Published: November 2010

AbstractCarboxymethyl cellulose (CMC) has been used widely to enhance dry strength of paper and uniformity of sheet in the papermaking industry. Besides these positive effects, it may affect the fines retention and dewatering processes negatively. These negative effects are mainly seen when fiber modifications with high CMC dosages are studied in laboratory scale. In this paper, the effect of fiber modification with CMC on the deposition of precipitated calcium carbonate (PCC) and on the dewatering process in the presence of cationic polyacrylamide (CPAM)/bentonite microparticle flocculation system is examined. It was determined that fiber modification with 10 mg g−1 of CMC decreased PCC deposition at the initial addition of CPAM and gave better PCC deposition at 2 mg g−1 of CPAM. It was also observed that PCC deposition on unmodified fibers is higher at lower CPAM concentration. PCC deposition was found as almost stable after a maximum value obtained at 0.5 mg g−1 of bentonite concentration for fiber modified with 40 mg g−1 of CMC. This indicates that interaction between CPAM and bentonite particles changed due to higher surface charge and CMC conformation on fibers. Results of the dewatering experiments showed that CMC modification increased the drainage time due to a denser and more plugged sheet. This negative effect was compensated with higher concentrations of CPAM and bentonite. On the other hand, dewatering is also affected by the mass ratio of CMC and CPAM, which was not the optimum one in this study at lower of CPAM. Thus, the increase in the drainage time in the presence of CMC on the fiber surface could be also caused by incorrect ratios of chemicals because the effect of CMC on the drainage time was not observed at higher concentrations of CPAM.
The future of the CAVE
Authors: DeFanti Thomas , Acevedo Daniel , Ainsworth Richard , Brown Maxine , Cutchin Steven , Dawe Gregory , Doerr Kai-Uwe , Johnson Andrew , Knox Chris , Kooima Robert , Kuester Falko , Leigh Jason , Long Lance , Otto Peter , Petrovic Vid , Ponto Kevin , Prudhomme Andrew , Rao Ramesh , Renambot Luc , Sandin Daniel , Schulze Jurgen , Smarr Larry , Srinivasan Madhu , Weber Philip , Wickham Gregory 
Published: November 2010

AbstractThe CAVE, a walk-in virtual reality environment typically consisting of 4–6 3 m-by-3 m sides of a room made of rear-projected screens, was first conceived and built in 1991. In the nearly two decades since its conception, the supporting technology has improved so that current CAVEs are much brighter, at much higher resolution, and have dramatically improved graphics performance. However, rear-projection-based CAVEs typically must be housed in a 10 m-by-10 m-by-10 m room (allowing space behind the screen walls for the projectors), which limits their deployment to large spaces. The CAVE of the future will be made of tessellated panel displays, eliminating the projection distance, but the implementation of such displays is challenging. Early multi-tile, panel-based, virtual-reality displays have been designed, prototyped, and built for the King Abdullah University of Science and Technology (KAUST) in Saudi Arabia by researchers at the University of California, San Diego, and the University of Illinois at Chicago. New means of image generation and control are considered key contributions to the future viability of the CAVE as a virtual-reality device.
Status and Prospects for Combined GPS LOD and VLBI UT1 Measurements
Authors: Senior K. , Kouba J. , Ray J. 
Published: November 2010

Status and Prospects for Combined GPS LOD and VLBI UT1 Measurements
A Kalman filter was developed to combine VLBI estimates of UT1-TAI with biased length of day (LOD) estimates from GPS. The VLBI results are the analyses of the NASA Goddard Space Flight Center group from 24-hr multi-station observing sessions several times per week and the nearly daily 1-hr single-baseline sessions. Daily GPS LOD estimates from the International GNSS Service (IGS) are combined with the VLBI UT1-TAI by modeling the natural excitation of LOD as the integral of a white noise process (i.e., as a random walk) and the UT1 variations as the integration of LOD, similar to the method described by Morabito et al. (1988). To account for GPS technique errors, which express themselves mostly as temporally correlated biases in the LOD measurements, a Gauss-Markov model has been added to assimilate the IGS data, together with a fortnightly sinusoidal term to capture errors in the IGS treatments of tidal effects. Evaluated against independent atmospheric and oceanic axial angular momentum (AAM + OAM) excitations and compared to other UT1/LOD combinations, ours performs best overall in terms of lowest RMS residual and highest correlation with (AAM + OAM) over sliding intervals down to 3 d. The IERS 05C04 and Bulletin A combinations show strong high-frequency smoothing and other problems. Until modified, the JPL SPACE series suffered in the high frequencies from not including any GPS-based LODs. We find, surprisingly, that further improvements are possible in the Kalman filter combination by selective rejection of some VLBI data. The best combined results are obtained by excluding all the 1-hr single-baseline UT1 data as well as those 24-hr UT1 measurements with formal errors greater than 5 μs (about 18% of the multi-baseline sessions). A rescaling of the VLBI formal errors, rather than rejection, was not an effective strategy. These results suggest that the UT1 errors of the 1-hr and weaker 24-hr VLBI sessions are non-Gaussian and more heterogeneous than expected, possibly due to the diversity of observing geometries used, other neglected systematic effects, or to the much shorter observational averaging interval of the single-baseline sessions. UT1 prediction services could benefit from better handling of VLBI inputs together with proper assimilation of IGS LOD products, including using the Ultra-rapid series that is updated four times daily with 15 hr delay.
Dynamical Modeling and Excitation Reconstruction as Fundamental of Earth Rotation Prediction
Authors: Zotov L. 
Published: November 2010

Dynamical Modeling and Excitation Reconstruction as Fundamental of Earth Rotation Prediction
Though pure mathematical approximations such as regression models and neural networks show good results in Earth rotation forecasting, dynamical modeling remains the only base for the physically meaningful prediction. That assumes the knowledge of cause-effect relationships and physical model of the rotating Earth. Excitation reconstruction from the observed Earth orientation parameters (EOP) is a crucial stage, needed for comparison with known causes, such as tidal forcing, atmospheric (AAM), oceanic (OAM) angular momentum changes, and uncovering unknown ones. We demonstrate different approaches, which can be used to avoid ill-conditionality and amplification of noises during the inversion. We present amplitude and phase studies of the model and reconstructed excitations of Chandler wobble. We found out, that modulation of Chandler excitation is synchronous with 18-yr tidal effects in the Earth's rotation rate changes. The results of the study can be used for excitation and EOP forecast. The key issues of the EOP prediction are discussed.
From Probate Inventories to a Data Set for the History of the Consumer Society
Authors: Schuurman Anton , Pastoor Gabriël 
Published: November 2010

In this article we present a set of computer applications for handling (probate) inventories. The programs have been developed at the Department of Rural History within the framework of aresearch programme for the history of consumption in the Netherlands: the MatCult Project. This project studies the development of consumer behaviour in the Netherlands from the sixteenth to the twentieth century. Special attention is given to regional and to town-country differences. The main sources are probate inventories. After a short overview of the history of the use of computers in inventory research, the Dbase TVapplications MatStore and MatCode are discussed. These programs allow the researcher to be flexible, detailed and economic. Firstly, the information from the inventories is stored as literally as possible in the computer. Secondly, this input is encoded and adapted for analysis using general statistical packages. Thus the programs provide a research tool that is capable of analysing inventories from different periods and locations and that allows international comparisons.
Estimating the time period between infection and diagnosis based on CD4+ counts at first diagnosis among HIV-1 antiretroviral naïve patients in Nigeria
Authors: Forbi Joseph C , Forbi Thanda D , Agwale Simon M 
Published: November 2010

Introduction: CD4+ T-cell levels are an important criterion for categorizing HIV-related clinical conditions. Late diagnosis of infection contributes to poor medical outcomes and the continuation of viral transmission. This population-based cohort study in north central Nigeria reports the initial CD4+ lymphocyte counts at the time of first HIV diagnosis and determines the approximate time interval when HIV infection was acquired.. Methodology: Confirmed HIV-1 infected individuals (n = 588) for whom the dates of first HIV diagnosis were known were enrolled in this study. CD4+ lymphocyte counts were measured using a Fluorescence Activated Cell Sorter (FACS) platform that automatically quantifies CD4+ lymphocytes as absolute numbers of lymphocytes per μL of blood. The estimated time interval between HIV infection and time of first HIV diagnosis was determined as a function of the CD4+ lymphocytes' decay rate per calendar year. Results: The results showed that 22.1% and 49.7% of HIV-infected individuals present late with advanced (CD4+: 200-349 cells/mL) and severe (CD4+: < 200 cells/mL) immunosuppression respectively, while only 12.1% present with CD4+ 500 cells/mL and 16.2%with CD4+ between 350-499 cells/mL. Mean CD4+ counts for females were higher when compared to those of males (p > 0.05), The time interval between HIV infection and first diagnosis was approximately 6.1 years for males and 7.3 years for females. Conclusion: The majority of HIV-infected individuals in this study accessed health care at late stages of infection, suggesting many HIV-infected individuals in Nigeria are unaware of their HIV status. More efficient programs for early diagnosis of HIV to prevent transmission are urgently required.
Influenza immunization rates, knowledge, attitudes and practices of health care workers in Iran
Authors: Khazaeipour Zahra , Ranjbarnovin Neda , Hoseini Najmesadat 
Published: November 2010

Introduction: This study aimed to determine influenza vaccine coverage and evaluate the knowledge, attitudes and practice about influenza and vaccine of health care workers in Tehran, Iran. Methodology: This cross-sectional survey involved 144 health care workers (HCWs) at the Tehran University of Medical Science between October 2008 and February 2009. Participants received a self-administered questionnaire directed at 35 items of knowledge and every correct response was scored one point. Results: Influenza vaccination coverage for the 2008-2009 season was 66.9 % (range, 45% to 62%). Most HCWs (80.6%) had received an influenza vaccination in the past, and 65.4% intended to receive vaccination in the coming year. The main reason given for being immunized was the effectiveness of the influenza vaccine (51.4%). The main reason given for not being immunized was concern about adverse effects (23.1%). The knowledge score for the 35 items ranged from 0 to 34 (mean 17.37). Mean knowledge scores differed between educational levels. There was no significant difference in mean knowledge scores between females and males (P > 0.05). Independent variables (age, sex, marital status, having children aged ≤ 16 years, educational level) were not significant predictors of taking influenza immunization. Conclusion: Despite the high coverage rate of influenza vaccination in our study, we would expect a higher rate because of free vaccine availability. The results indicate the need for on-going education of influenza disease among HCWs to increase vaccination rates.