Characterisation of diode-connected SiGe BiCMOS HBTs for space applications

Science.gov (United States)

Venter, Johan; Sinha, Saurabh; Lambrechts, Wynand

2016-02-01

Silicon-germanium (SiGe) bipolar complementary metal-oxide semiconductor (BiCMOS) transistors have vertical doping profiles reaching deeper into the substrate when compared to lateral CMOS transistors. Apart from benefiting from high-speed, high current gain and low-output resistance due to its vertical profile, BiCMOS technology is increasingly becoming a preferred technology for researchers to realise next-generation space-based optoelectronic applications. BiCMOS transistors have inherent radiation hardening, to an extent predictable cryogenic performance and monolithic integration potential. SiGe BiCMOS transistors and p-n junction diodes have been researched and used as a primary active component for over the last two decades. However, further research can be conducted with diode-connected heterojunction bipolar transistors (HBTs) operating at cryogenic temperatures. This work investigates these characteristics and models devices by adapting standard fabrication technology components. This work focuses on measurements of the current-voltage relationship (I-V curves) and capacitance-voltage relationships (C-V curves) of diode-connected HBTs. One configuration is proposed and measured, which is emitterbase shorted. The I-V curves are measured for various temperature points ranging from room temperature (300 K) to the temperature of liquid nitrogen (77 K). The measured datasets are used to extract a model of the formed diode operating at cryogenic temperatures and used as a standard library component in computer aided software designs. The advantage of having broad-range temperature models of SiGe transistors becomes apparent when considering implementation of application-specific integrated circuits and silicon-based infrared radiation photodetectors on a single wafer, thus shortening interconnects and lowering parasitic interference, decreasing the overall die size and improving on overall cost-effectiveness. Primary applications include space-based geothermal

Color image segmentation using perceptual spaces through applets ...

African Journals Online (AJOL)

Color image segmentation using perceptual spaces through applets for determining and preventing diseases in chili peppers. JL González-Pérez, MC Espino-Gudiño, J Gudiño-Bazaldúa, JL Rojas-Rentería, V Rodríguez-Hernández, VM Castaño ...

Image Segmentation and Processing for Efficient Parking Space Analysis

OpenAIRE

Tutika, Chetan Sai; Vallapaneni, Charan; R, Karthik; KP, Bharath; Muthu, N Ruban Rajesh Kumar

2018-01-01

In this paper, we develop a method to detect vacant parking spaces in an environment with unclear segments and contours with the help of MATLAB image processing capabilities. Due to the anomalies present in the parking spaces, such as uneven illumination, distorted slot lines and overlapping of cars. The present-day conventional algorithms have difficulties processing the image for accurate results. The algorithm proposed uses a combination of image pre-processing and false contour detection ...

Reliability analysis of an LCL tuned track segmented bi-directional inductive power transfer system

DEFF Research Database (Denmark)

Asif Iqbal, S. M.; Madawala, U. K.; Thrimawithana, D. J.

2013-01-01

Bi-directional Inductive Power Transfer (BDIPT) technique is suitable for renewable energy based applications such as electric vehicles (EVs), for the implementation of vehicle-to-grid (V2G) systems. Recently, more efforts have been made by researchers to improve both efficiency and reliability...... of renewable energy systems to further enhance their economical sustainability. This paper presents a comparative reliability study between a typical BDIPT system and an individually controlled segmented BDIPT system. Steady state thermal simulation results are provided for different output power levels...... for a 1.5 kW BDIPT system in a MATLAB/Simulink environment. Reliability parameters such as failure rate and mean time between failures (MTBF) are compared between the two systems. A nonlinear programming (NP) model is developed for optimizing charging schedule for a stationery EV. A case study of EV...

Anterior segment developmental anomalies in a 33-week-old fetus with MIDAS syndrome.

Science.gov (United States)

Herwig, Martina C; Loeffler, Karin U; Gembruch, Ulrich; Kuchelmeister, Klaus; Müller, Annette M

2014-01-01

We report anterior segment abnormalities in both eyes of a 33-week-old fetus endorsing the diagnosis of MIDAS (microphthalmia, dermal aplasia, and sclerocornea) syndrome. After abortion, the fetus was examined by a standard pediatric autopsy that included macroscopic and microscopic examination of both eyes. Postmortem findings included craniofacial stigmata (such as hypertelorism, a flat nose and low-set ears) and an agenesis of the corpus callosum. Array comparative genomic hybridization revealed a deletion of the short arm of the X chromosome (region Xp22.2 to p22.32). Ophthalmopathologic examination of the eyes revealed microphthalmia with anterior segment developmental anomalies, in particular sclerocornea and Peters' anomaly, respectively. General pathology findings plus the ocular findings allowed the diagnosis of MIDAS syndrome. A discussion of differential diagnoses is provided. This case report indicates that ophthalmopathologic investigation of fetal eyes can be of great value for the further classification of syndromes.

Color segmentation in the HSI color space using the K-means algorithm

Science.gov (United States)

Weeks, Arthur R.; Hague, G. Eric

1997-04-01

Segmentation of images is an important aspect of image recognition. While grayscale image segmentation has become quite a mature field, much less work has been done with regard to color image segmentation. Until recently, this was predominantly due to the lack of available computing power and color display hardware that is required to manipulate true color images (24-bit). TOday, it is not uncommon to find a standard desktop computer system with a true-color 24-bit display, at least 8 million bytes of memory, and 2 gigabytes of hard disk storage. Segmentation of color images is not as simple as segmenting each of the three RGB color components separately. The difficulty of using the RGB color space is that it doesn't closely model the psychological understanding of color. A better color model, which closely follows that of human visual perception is the hue, saturation, intensity model. This color model separates the color components in terms of chromatic and achromatic information. Strickland et al. was able to show the importance of color in the extraction of edge features form an image. His method enhances the edges that are detectable in the luminance image with information from the saturation image. Segmentation of both the saturation and intensity components is easily accomplished with any gray scale segmentation algorithm, since these spaces are linear. The modulus 2(pi) nature of the hue color component makes its segmentation difficult. For example, a hue of 0 and 2(pi) yields the same color tint. Instead of applying separate image segmentation to each of the hue, saturation, and intensity components, a better method is to segment the chromatic component separately from the intensity component because of the importance that the chromatic information plays in the segmentation of color images. This paper presents a method of using the gray scale K-means algorithm to segment 24-bit color images. Additionally, this paper will show the importance the hue

Space growth studies of Ce-doped Bi12SiO20 single crystal

International Nuclear Information System (INIS)

Zhou, Y.F.; Wang, J.C.; Tang, L.A.; Pan, Z.L.; Chen, N.F.; Chen, W.C.; Huang, Y.Y.; He, W.

2004-01-01

Ce-doped Bi 12 SiO 20 (BSO) single crystal was grown on board of the Chinese Spacecraft-Shenzhou No. 3. A cylindrical crystal, 10 mm in diameter and 40 mm in length, was obtained. The morphology of crystals is significantly different for ground- and space-grown portions. The space- and ground-grown crystals have been characterized by Ce concentration distribution, X-ray rocking curve absorption spectrum and micro-Raman spectrum. The results show that the quality of Ce-doped BSO crystal grown in space is more homogeneous and more perfect than that of ground grown one

Categories of dicompact BI- T 2 texture spaces and a Banach-stone ...

African Journals Online (AJOL)

The principal aim of this paper is to consider various aspects of the theory of dicompact bi-T2 texture spaces, and place them in a categorical setting. It culminates in a version of the Banach-Stone theorem. On the way, a new class of textures, called here nearly plain textures, is seen to play a crucial role in the development ...

High Energy, Low Temperature Gelled Bi-Propellant Formulation for Long-Duration In-Space Propulsion, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Development of a candidate bi-propellant system consisting of a gelled hydrocarbon fuel coupled with a highly energetic gelled oxidizer suitable for outer planetary...

Performance of a highly segmented scintillating fibres electromagnetic calorimeter

International Nuclear Information System (INIS)

Asmone, A.; Bertino, M.; Bini, C.; De Zorzi, G.; Diambrini Palazzi, G.; Di Cosimo, G.; Di Domenico, A.; Garufi, F.; Gauzzi, P.; Zanello, D.

1993-01-01

A prototype of scintillating fibres electromagnetic calorimeter has been constructed and tested with 2, 4 and 8 GeV electron beams at the CERN PS. The calorimeter modules consist of a Bi-Pb-Sn alloy and scintillating fibres. The fibres are parallel to the modules longer axis, and nearly parallel to the incident electrons direction. The calorimeter has two different segmentation regions of 24x24 mm 2 and 8x24 mm 2 cross area respectively. Results on energy and impact point space resolution are obtained and compared for the two different granularities. (orig.)

Strength of tensed and compressed concrete segments in crack spacing under short-term dynamic load

Directory of Open Access Journals (Sweden)

Galyautdinov Zaur

2018-01-01

Full Text Available Formation of model describing dynamic straining of reinforced concrete requires taking into account the basic aspects influencing the stress-strain state of structures. Strength of concrete segments in crack spacing is one of the crucial aspects that affect general strain behavior of reinforced concrete. Experimental results demonstrate significant change in strength of tensed and compressed concrete segments in crack spacing both under static and under dynamic loading. In this case, strength depends on tensile strain level and the slope angle of rebars towards the cracks direction. Existing theoretical and experimental studies estimate strength of concrete segments in crack spacing under static loading. The present work presents results of experimental and theoretical studies of dynamic strength of plates between cracks subjected to compression-tension. Experimental data was analyzed statistically; the dependences were suggested to describe dynamic strength of concrete segments depending on tensile strain level and slope angle of rebars to cracks direction.

Frictionless segmented mechanics for controlled space closure.

Science.gov (United States)

Andrade, Ildeu

2017-02-01

Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO) in partial fulfillment of the requirements for Diplomate certification.

Microstructure Of MnBi/Bi Eutectic Alloy

Science.gov (United States)

Wilcox, William R.; Eisa, G. F.; Baskaran, B.; Richardson, Donald C.

1988-01-01

Collection of three reports describes studies of directional solidification of MnBi/Bi eutectic alloy. Two of the reports, "Influence of Convection on Lamellar Spacing of Eutectics" and "Influence of Convection on Eutectic Microstructure," establish theoretical foundation for remaining document. Reports seek to quantify effect of convection on concentration field of growing lamellar eutectic. Remaining report, "Study of Eutectic Formation," begins by continuing theoretical developments. New technique under development by one of the authors helps to reveal three-dimensional microstructures of alloys.

Decomposing the Hounsfield unit: probabilistic segmentation of brain tissue in computed tomography.

Science.gov (United States)

Kemmling, A; Wersching, H; Berger, K; Knecht, S; Groden, C; Nölte, I

2012-03-01

The aim of this study was to present and evaluate a standardized technique for brain segmentation of cranial computed tomography (CT) using probabilistic partial volume tissue maps based on a database of high resolution T1 magnetic resonance images (MRI). Probabilistic tissue maps of white matter (WM), gray matter (GM) and cerebrospinal fluid (CSF) were derived from 600 normal brain MRIs (3.0 Tesla, T1-3D-turbo-field-echo) of 2 large community-based population studies (BiDirect and SEARCH Health studies). After partial tissue segmentation (FAST 4.0), MR images were linearly registered to MNI-152 standard space (FLIRT 5.5) with non-linear refinement (FNIRT 1.0) to obtain non-binary probabilistic volume images for each tissue class which were subsequently used for CT segmentation. From 150 normal cerebral CT scans a customized reference image in standard space was constructed with iterative non-linear registration to MNI-152 space. The inverse warp of tissue-specific probability maps to CT space (MNI-152 to individual CT) was used to decompose a CT image into tissue specific components (GM, WM, CSF). Potential benefits and utility of this novel approach with regard to unsupervised quantification of CT images and possible visual enhancement are addressed. Illustrative examples of tissue segmentation in different pathological cases including perfusion CT are presented. Automated tissue segmentation of cranial CT images using highly refined tissue probability maps derived from high resolution MR images is feasible. Potential applications include automated quantification of WM in leukoaraiosis, CSF in hydrocephalic patients, GM in neurodegeneration and ischemia and perfusion maps with separate assessment of GM and WM.

The k-space origins of scattering in Bi2Sr2CaCu2O8+x.

Science.gov (United States)

Alldredge, Jacob W; Calleja, Eduardo M; Dai, Jixia; Eisaki, H; Uchida, S; McElroy, Kyle

2013-08-21

We demonstrate a general, computer automated procedure that inverts the reciprocal space scattering data (q-space) that are measured by spectroscopic imaging scanning tunnelling microscopy (SI-STM) in order to determine the momentum space (k-space) scattering structure. This allows a detailed examination of the k-space origins of the quasiparticle interference (QPI) pattern in Bi2Sr2CaCu2O8+x within the theoretical constraints of the joint density of states (JDOS). Our new method allows measurement of the differences between the positive and negative energy dispersions, the gap structure and an energy dependent scattering length scale. Furthermore, it resolves the transition between the dispersive QPI and the checkerboard ([Formula: see text] excitation). We have measured the k-space scattering structure over a wide range of doping (p ∼ 0.22-0.08), including regions where the octet model is not applicable. Our technique allows the complete mapping of the k-space scattering origins of the spatial excitations in Bi2Sr2CaCu2O8+x, which allows for better comparisons between SI-STM and other experimental probes of the band structure. By applying our new technique to such a heavily studied compound, we can validate our new general approach for determining the k-space scattering origins from SI-STM data.

Frictionless segmented mechanics for controlled space closure

Directory of Open Access Journals (Sweden)

Ildeu Andrade Jr

Full Text Available ABSTRACT Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extraction site. Another treatment objective may require the opposite, or any number of intentional alternatives of extraction site closure. The present case report describes a simple controlled segmented mechanic system that permitted definable and predictable force systems to be applied and allowed to predict the treatment outcome with confidence. This case was presented to the Brazilian Board of Orthodontics and Dentofacial Orthopedics (BBO in partial fulfillment of the requirements for Diplomate certification.

Phase modulation spectroscopy of space-charge wave resonances in Bi12SiO20

DEFF Research Database (Denmark)

Vasnetsov, M.; Buchhave, Preben; Lyuksyutov, S.

1997-01-01

A new experimental method for the study of resonance effects and space-charge wave excitation in photorefractive Bi12SiO20 crystals by using a combination of frequency detuning and phase modulation technique has been developed. The accuracy of the method allows a detection of resonance peaks...... of diffraction efficiency within 0.5 Hz. Numerical simulations of the nonlinear differential equations describing the behaviour of the space-charge waves in photorefractive crystals have been performed and found to be in a good agreement with experiment. We have measured the photocurrent through the crystal...

Angular Spacing Control for Segmented Data Pages in Angle-Multiplexed Holographic Memory

Science.gov (United States)

Kinoshita, Nobuhiro; Muroi, Tetsuhiko; Ishii, Norihiko; Kamijo, Koji; Kikuchi, Hiroshi; Shimidzu, Naoki; Ando, Toshio; Masaki, Kazuyoshi; Shimizu, Takehiro

2011-09-01

To improve the recording density of angle-multiplexed holographic memory, it is effective to increase the numerical aperture of the lens and to shorten the wavelength of the laser source as well as to increase the multiplexing number. The angular selectivity of a hologram, which determines the multiplexing number, is dependent on the incident angle of not only the reference beam but also the signal beam to the holographic recording medium. The actual signal beam, which is a convergent or divergent beam, is regarded as the sum of plane waves that have different propagation directions, angular selectivities, and optimal angular spacings. In this paper, focusing on the differences in the optimal angular spacing, we proposed a method to control the angular spacing for each segmented data page. We investigated the angular selectivity of a hologram and crosstalk for segmented data pages using numerical simulation. The experimental results showed a practical bit-error rate on the order of 10-3.

Orthographic Transparency Enhances Morphological Segmentation in Children Reading Hebrew Words

Science.gov (United States)

Haddad, Laurice; Weiss, Yael; Katzir, Tami; Bitan, Tali

2018-01-01

Morphological processing of derived words develops simultaneously with reading acquisition. However, the reader’s engagement in morphological segmentation may depend on the language morphological richness and orthographic transparency, and the readers’ reading skills. The current study tested the common idea that morphological segmentation is enhanced in non-transparent orthographies to compensate for the absence of phonological information. Hebrew’s rich morphology and the dual version of the Hebrew script (with and without diacritic marks) provides an opportunity to study the interaction of orthographic transparency and morphological segmentation on the development of reading skills in a within-language design. Hebrew speaking 2nd (N = 27) and 5th (N = 29) grade children read aloud 96 noun words. Half of the words were simple mono-morphemic words and half were bi-morphemic derivations composed of a productive root and a morphemic pattern. In each list half of the words were presented in the transparent version of the script (with diacritic marks), and half in the non-transparent version (without diacritic marks). Our results show that in both groups, derived bi-morphemic words were identified more accurately than mono-morphemic words, but only for the transparent, pointed, script. For the un-pointed script the reverse was found, namely, that bi-morphemic words were read less accurately than mono-morphemic words, especially in second grade. Second grade children also read mono-morphemic words faster than bi-morphemic words. Finally, correlations with a standardized measure of morphological awareness were found only for second grade children, and only in bi-morphemic words. These results, showing greater morphological effects in second grade compared to fifth grade children suggest that for children raised in a language with a rich morphology, common and easily segmented morphemic units may be more beneficial for younger compared to older readers. Moreover

Orthographic Transparency Enhances Morphological Segmentation in Children Reading Hebrew Words

Directory of Open Access Journals (Sweden)

Laurice Haddad

2018-01-01

Full Text Available Morphological processing of derived words develops simultaneously with reading acquisition. However, the reader’s engagement in morphological segmentation may depend on the language morphological richness and orthographic transparency, and the readers’ reading skills. The current study tested the common idea that morphological segmentation is enhanced in non-transparent orthographies to compensate for the absence of phonological information. Hebrew’s rich morphology and the dual version of the Hebrew script (with and without diacritic marks provides an opportunity to study the interaction of orthographic transparency and morphological segmentation on the development of reading skills in a within-language design. Hebrew speaking 2nd (N = 27 and 5th (N = 29 grade children read aloud 96 noun words. Half of the words were simple mono-morphemic words and half were bi-morphemic derivations composed of a productive root and a morphemic pattern. In each list half of the words were presented in the transparent version of the script (with diacritic marks, and half in the non-transparent version (without diacritic marks. Our results show that in both groups, derived bi-morphemic words were identified more accurately than mono-morphemic words, but only for the transparent, pointed, script. For the un-pointed script the reverse was found, namely, that bi-morphemic words were read less accurately than mono-morphemic words, especially in second grade. Second grade children also read mono-morphemic words faster than bi-morphemic words. Finally, correlations with a standardized measure of morphological awareness were found only for second grade children, and only in bi-morphemic words. These results, showing greater morphological effects in second grade compared to fifth grade children suggest that for children raised in a language with a rich morphology, common and easily segmented morphemic units may be more beneficial for younger compared to older

Optimization of the segmented method for optical compression and multiplexing system

Science.gov (United States)

Al Falou, Ayman

2002-05-01

Because of the constant increasing demands of images exchange, and despite the ever increasing bandwidth of the networks, compression and multiplexing of images is becoming inseparable from their generation and display. For high resolution real time motion pictures, electronic performing of compression requires complex and time-consuming processing units. On the contrary, by its inherent bi-dimensional character, coherent optics is well fitted to perform such processes that are basically bi-dimensional data handling in the Fourier domain. Additionally, the main limiting factor that was the maximum frame rate is vanishing because of the recent improvement of spatial light modulator technology. The purpose of this communication is to benefit from recent optical correlation algorithms. The segmented filtering used to store multi-references in a given space bandwidth product optical filter can be applied to networks to compress and multiplex images in a given bandwidth channel.

Design and Optimization of Effective Segmented Thermoelectric Generator for Waste Heat Recovery

DEFF Research Database (Denmark)

Pham, Hoang Ngan

ranges of 300 ‒ 700, and 900 – 1100 K are considered. The obtained results reveals that segmented thermoelectric generator comprising of Bi0.6Sb1.4Te3/Ba8Au5.3Ge40.7/PbTe-SrTe/SiGe as p-leg and either segmented Bi2Te3/PbTe/SiGe or Bi2Te3/Ba0.08La0.05Yb0.04Co4Sb12/La3Te4 as n-leg working in 300 – 1100 K...... been focused on material development, realizing high efficient thermoelectric generators from such well-developed materials is still limited. Moreover, no single thermoelectric material could withstand the wide temperature range required to boost efficiency of TEGs. By segmentation of different TE...... materials which operate optimally in each temperature range, this study aims at developing high performance segmented TEGs for medium-high (450 – 850 K) temperature application. The research is focused on the challenges in joining and minimizing the contact resistances between different TE materials...

[sup 205]Bi/[sup 206]Bi cyclotron production from Pb-isotopes for absorption studies in humans

Energy Technology Data Exchange (ETDEWEB)

Fischer, R.; Dresow, B.; Heinrich, H.C. (Universitaetskrankenhaus Eppendorf, Hamburg (Germany). Abt. Medizinische Biochemie); Wendel, J.; Bechtold, V. (Kernforschungszentrum Karlsruhe GmbH (Germany). Inst. fuer Kernphysik)

1993-12-01

Pb(p,xn) thick target excitation functions were measured in the energy range 10-38 MeV in order to optimize the production of isotopically pure radiobismuth from [sup nat]Pb, [sup 206]Pb, and [sup 207]Pb. Additionally, the decay of Po-isotopes from deuteron irradiation of natural bismuth ([sup 209]Bi) was exploited for radiobismuth production. [sup 205]Bi was produced from [sup 206]Pb at 20 MeV with only 2% of [sup 206]Bi at 4 weeks post irradiation. Bismuth compounds as used in the treatment of peptic ulcer were labeled with [sup 205]Bi for absorption studies in animals and subjects. (Author).

Space charge limited current conduction in Bi2Te3 thin films

International Nuclear Information System (INIS)

Sathyamoorthy, R.; Dheepa, J.; Velumani, S.

2007-01-01

Bi 2 Te 3 is known for its large thermoelectric coefficients and is widely used as a material for Peltier devices. Bi 2 Te 3 thin films with thicknesses in the range 125-300 A have been prepared by Flash Evaporation at a pressure of 10 -5 m bar on clean glass substrates at room temperature. An Al-Bi 2 Te 3 -Al sandwich structure has been used for electrical conduction properties in the temperature range 303 to 483 K. I-V characteristics showed Ohmic conduction in the low voltage region. In the higher voltage region, a Space Charge Limited Conduction (SCLC) takes place due to the presence of the trapping level. The transition voltage (V t ), between the Ohmic and the SCLC condition was proportional to the square of thickness. Further evidence for this conduction process was provided by the linear dependence of V t on t 2 and log J on log t. The hole concentration in the films were found to be n 0 = 1.65 * 10 10 m -3 . The carrier mobility increases with increasing temperature whereas the density of trapped charges decreases with increasing temperature. The barrier height decreases with an increase in temperature. The increase in the trapping concentration V t is correlated with ascending the degree of preferred orientation of the highest atomic density plane. The activation energy was estimated and the values found to decrease with increasing applied voltage. The zero field value of the activation energy is found to be 0.4 eV

A segmented appliance for space closure followed by Invisalign and fixed appliances.

Science.gov (United States)

Uribe, Flavio; Cutrera, Alice; Nanda, Ravinda

2011-01-01

This case report describes the use of a segmented appliance for space closure prior to using Invisalign. The maxillary right canine was retracted into the extracted first premolar space with a sectional wire from the first molar to the canine with no visible brackets in the incisor region. The advantage of this technique is the ability to achieve better root and rotational control during space closure with a fixed appliance that also has limited visibility. A maxillary fixed appliance was used to refine the esthetics in the maxillary arch due to the limitations of the Invisalign appliance in achieving rotational and vertical movements.

Like Fun Quantitative and Qualitative Analysis of the Entertainment Programs in BiH

Directory of Open Access Journals (Sweden)

Sanja Dokić Mrša

2015-09-01

Full Text Available According to the data from the Communications Regulatory Agency of Bosnia and Herzegovina, entertaining programme constitutes a quarter of all TV stations broadcast (24.9% and more than half of radio stations broadcast (53.66%. The content analysis of television programmes of three public broadcasters (BHT 1, RTRS, FTV as well as two commercial TV stations with nationwide coverage (TV Hayat and TV BN in prime time (from 17 to 23 hours on weekly base, based on the review of the programmes, showed that entertainment is one of the most important segments of television programmes, on both commercial TV stations, as well as public service in BiH. Qualitative analysis of Grand Show, that stands for the one of the most popular music and entertainment shows, not only in BiH, but wider, for almost two decades, indicates that this show belongs to kitsch culture. Furthermore, certain similarities between reality show programs like Big Brother or Farm and french Theatre of the absurd were found.

Validity of segmental bioelectrical impedance analysis for estimating fat-free mass in children including overweight individuals.

Science.gov (United States)

Ohta, Megumi; Midorikawa, Taishi; Hikihara, Yuki; Masuo, Yoshihisa; Sakamoto, Shizuo; Torii, Suguru; Kawakami, Yasuo; Fukunaga, Tetsuo; Kanehisa, Hiroaki

2017-02-01

This study examined the validity of segmental bioelectrical impedance (BI) analysis for predicting the fat-free masses (FFMs) of whole-body and body segments in children including overweight individuals. The FFM and impedance (Z) values of arms, trunk, legs, and whole body were determined using a dual-energy X-ray absorptiometry and segmental BI analyses, respectively, in 149 boys and girls aged 6 to 12 years, who were divided into model-development (n = 74), cross-validation (n = 35), and overweight (n = 40) groups. Simple regression analysis was applied to (length) 2 /Z (BI index) for each of the whole-body and 3 segments to develop the prediction equations of the measured FFM of the related body part. In the model-development group, the BI index of each of the 3 segments and whole body was significantly correlated to the measured FFM (R 2 = 0.867-0.932, standard error of estimation = 0.18-1.44 kg (5.9%-8.7%)). There was no significant difference between the measured and predicted FFM values without systematic error. The application of each equation derived in the model-development group to the cross-validation and overweight groups did not produce significant differences between the measured and predicted FFM values and systematic errors, with an exception that the arm FFM in the overweight group was overestimated. Segmental bioelectrical impedance analysis is useful for predicting the FFM of each of whole-body and body segments in children including overweight individuals, although the application for estimating arm FFM in overweight individuals requires a certain modification.

Wavelet-space correlation imaging for high-speed MRI without motion monitoring or data segmentation.

Science.gov (United States)

Li, Yu; Wang, Hui; Tkach, Jean; Roach, David; Woods, Jason; Dumoulin, Charles

2015-12-01

This study aims to (i) develop a new high-speed MRI approach by implementing correlation imaging in wavelet-space, and (ii) demonstrate the ability of wavelet-space correlation imaging to image human anatomy with involuntary or physiological motion. Correlation imaging is a high-speed MRI framework in which image reconstruction relies on quantification of data correlation. The presented work integrates correlation imaging with a wavelet transform technique developed originally in the field of signal and image processing. This provides a new high-speed MRI approach to motion-free data collection without motion monitoring or data segmentation. The new approach, called "wavelet-space correlation imaging", is investigated in brain imaging with involuntary motion and chest imaging with free-breathing. Wavelet-space correlation imaging can exceed the speed limit of conventional parallel imaging methods. Using this approach with high acceleration factors (6 for brain MRI, 16 for cardiac MRI, and 8 for lung MRI), motion-free images can be generated in static brain MRI with involuntary motion and nonsegmented dynamic cardiac/lung MRI with free-breathing. Wavelet-space correlation imaging enables high-speed MRI in the presence of involuntary motion or physiological dynamics without motion monitoring or data segmentation. © 2014 Wiley Periodicals, Inc.

A hierarchical integrated population model for greater sage-grouse (Centrocercus urophasianus) in the Bi-State Distinct Population Segment, California and Nevada

Science.gov (United States)

Coates, Peter S.; Halstead, Brian J.; Blomberg, Erik J.; Brussee, Brianne; Howe, Kristy B.; Wiechman, Lief; Tebbenkamp, Joel; Reese, Kerry P.; Gardner, Scott C.; Casazza, Michael L.

2014-01-01

Greater sage-grouse (Centrocercus urophasianus, hereafter referred to as “sage-grouse”) are endemic to sagebrush (Artemisia spp.) ecosystems throughout Western North America. Populations of sage-grouse have declined in distribution and abundance across the range of the species (Schroeder and others, 2004; Knick and Connelly, 2011), largely as a result of human disruption of sagebrush communities (Knick and Connelly, 2011). The Bi-State Distinct Population Segment (DPS) represents sage-grouse populations that are geographically isolated and genetically distinct (Benedict and others, 2003; Oyler-McCance and others, 2005) and that are present at the extreme southwestern distribution of the sage-grouse range (Schroeder and others, 2004), straddling the border of California and Nevada. Subpopulations of sage-grouse in the DPS may be at increased risk of extirpation because of a substantial loss of sagebrush habitat and lack of connectivity (Oyler-McCance and others, 2005). Sage-grouse in the Bi-State DPS represent small, localized breeding populations distributed across 18,325 km2. The U.S. Fish and Wildlife Service currently (2014) is evaluating the Bi-State DPS as threatened or endangered under the Endangered Species Act of 1973, independent of other sage-grouse populations. This DPS was designated as a higher priority for listing than sage-grouse in other parts of the species’ range (U.S. Department of the Interior, 2010). Range-wide population analyses for sage-grouse have included portions of the Bi-State DPS (Sage and Columbian Sharp-tailed Grouse Technical Committee 2008; Garton and others, 2011). Although these analyses are informative, the underlying data only represent a portion of the DPS and are comprised of lek count observations only. A thorough examination of population dynamics and persistence that includes multiple subpopulations and represents the majority of the DPS is largely lacking. Furthermore, fundamental information on population growth

Bi-articular Knee-Ankle-Foot Exoskeleton Produces Higher Metabolic Cost Reduction than Weight-Matched Mono-articular Exoskeleton

Science.gov (United States)

Malcolm, Philippe; Galle, Samuel; Derave, Wim; De Clercq, Dirk

2018-01-01

The bi-articular m. gastrocnemius and the mono-articular m. soleus have different and complementary functions during walking. Several groups are starting to use these biological functions as inspiration to design prostheses with bi-articular actuation components to replace the function of the m. gastrocnemius. Simulation studies indicate that a bi-articular configuration and spring that mimic the m. gastrocnemius could be beneficial for orthoses or exoskeletons. Our aim was to test the effect of a bi-articular and spring configuration that mimics the m. gastrocnemius and compare this to a no-spring and mono-articular configuration. We tested nine participants during walking with knee-ankle-foot exoskeletons with dorsally mounted pneumatic muscle actuators. In the bi-articular plus spring condition the pneumatic muscles were attached to the thigh segment with an elastic cord. In the bi-articular no-spring condition the pneumatic muscles were also attached to the thigh segment but with a non-elastic cord. In the mono-articular condition the pneumatic muscles were attached to the shank segment. We found the highest reduction in metabolic cost of 13% compared to walking with the exoskeleton powered-off in the bi-articular plus spring condition. Possible explanations for this could be that the exoskeleton delivered the highest total positive work in this condition at the ankle and the knee and provided more assistance during the isometric phase of the biological plantarflexors. As expected we found that the bi-articular conditions reduced m. gastrocnemius EMG more than the mono-articular condition but this difference was not significant. We did not find that the mono-articular condition reduces the m. soleus EMG more than the bi-articular conditions. Knowledge of specific effects of different exoskeleton configurations on metabolic cost and muscle activation could be useful for providing customized assistance for specific gait impairments. PMID:29551959

Bi-articular Knee-Ankle-Foot Exoskeleton Produces Higher Metabolic Cost Reduction than Weight-Matched Mono-articular Exoskeleton

Directory of Open Access Journals (Sweden)

Philippe Malcolm

2018-03-01

Full Text Available The bi-articular m. gastrocnemius and the mono-articular m. soleus have different and complementary functions during walking. Several groups are starting to use these biological functions as inspiration to design prostheses with bi-articular actuation components to replace the function of the m. gastrocnemius. Simulation studies indicate that a bi-articular configuration and spring that mimic the m. gastrocnemius could be beneficial for orthoses or exoskeletons. Our aim was to test the effect of a bi-articular and spring configuration that mimics the m. gastrocnemius and compare this to a no-spring and mono-articular configuration. We tested nine participants during walking with knee-ankle-foot exoskeletons with dorsally mounted pneumatic muscle actuators. In the bi-articular plus spring condition the pneumatic muscles were attached to the thigh segment with an elastic cord. In the bi-articular no-spring condition the pneumatic muscles were also attached to the thigh segment but with a non-elastic cord. In the mono-articular condition the pneumatic muscles were attached to the shank segment. We found the highest reduction in metabolic cost of 13% compared to walking with the exoskeleton powered-off in the bi-articular plus spring condition. Possible explanations for this could be that the exoskeleton delivered the highest total positive work in this condition at the ankle and the knee and provided more assistance during the isometric phase of the biological plantarflexors. As expected we found that the bi-articular conditions reduced m. gastrocnemius EMG more than the mono-articular condition but this difference was not significant. We did not find that the mono-articular condition reduces the m. soleus EMG more than the bi-articular conditions. Knowledge of specific effects of different exoskeleton configurations on metabolic cost and muscle activation could be useful for providing customized assistance for specific gait impairments.

Bi-articular Knee-Ankle-Foot Exoskeleton Produces Higher Metabolic Cost Reduction than Weight-Matched Mono-articular Exoskeleton.

Science.gov (United States)

Malcolm, Philippe; Galle, Samuel; Derave, Wim; De Clercq, Dirk

2018-01-01

The bi-articular m. gastrocnemius and the mono-articular m. soleus have different and complementary functions during walking. Several groups are starting to use these biological functions as inspiration to design prostheses with bi-articular actuation components to replace the function of the m. gastrocnemius. Simulation studies indicate that a bi-articular configuration and spring that mimic the m. gastrocnemius could be beneficial for orthoses or exoskeletons. Our aim was to test the effect of a bi-articular and spring configuration that mimics the m. gastrocnemius and compare this to a no-spring and mono-articular configuration. We tested nine participants during walking with knee-ankle-foot exoskeletons with dorsally mounted pneumatic muscle actuators. In the bi-articular plus spring condition the pneumatic muscles were attached to the thigh segment with an elastic cord. In the bi-articular no-spring condition the pneumatic muscles were also attached to the thigh segment but with a non-elastic cord. In the mono-articular condition the pneumatic muscles were attached to the shank segment. We found the highest reduction in metabolic cost of 13% compared to walking with the exoskeleton powered-off in the bi-articular plus spring condition . Possible explanations for this could be that the exoskeleton delivered the highest total positive work in this condition at the ankle and the knee and provided more assistance during the isometric phase of the biological plantarflexors. As expected we found that the bi-articular conditions reduced m. gastrocnemius EMG more than the mono-articular condition but this difference was not significant. We did not find that the mono-articular condition reduces the m. soleus EMG more than the bi-articular conditions . Knowledge of specific effects of different exoskeleton configurations on metabolic cost and muscle activation could be useful for providing customized assistance for specific gait impairments.

Response of MnBi-Bi eutectic to freezing rate changes

Science.gov (United States)

Nair, M.; Fu, T.-W.; Wilcox, W. R.; Doddi, K.; Ravishankar, P. S.; Larson, D.

1982-01-01

Reference is made to a study by Fu and Wilcox (1981), which treated theoretically the influence on freezing rate of sudden changes in translation rate in the Bridgman-Stockbarger technique. This treatment is extended here to a linear ramped translation rate and an oscillatory freezing rate. It is found that oscillations above a few hertz are highly damped in small-diameter apparatus. An experimental test is carried out of the theoretical predictions for a sudden change of translation rate. The MnBi-Bi eutectic is solidified with current-induced interface demarcation. The experimental results accord reasonably well with theory if the silica ampoule wall is assumed to either (1) contribute only a resistance to heat exchange between the sample and the furnace wall or (2) transmit heat effectively in the axial direction by radiation. In an attempt to explain the fact that a finer microstructure is obtained in space, MnBi-Bi microstructure is determined when the freezing rate is increased or decreased rapidly. Preliminary results suggest that fiber branching does not occur as readily as fiber termination.

Apodized Pupil Lyot Coronagraphs designs for future segmented space telescopes

Science.gov (United States)

St. Laurent, Kathryn; Fogarty, Kevin; Zimmerman, Neil; N’Diaye, Mamadou; Stark, Chris; Sivaramakrishnan, Anand; Pueyo, Laurent; Vanderbei, Robert; Soummer, Remi

2018-01-01

A coronagraphic starlight suppression system situated on a future flagship space observatory offers a promising avenue to image Earth-like exoplanets and search for biomarkers in their atmospheric spectra. One NASA mission concept that could serve as the platform to realize this scientific breakthrough is the Large UV/Optical/IR Surveyor (LUVOIR). Such a mission would also address a broad range of topics in astrophysics with a multi-wavelength suite of instruments.In support of the community’s assessment of the scientific capability of a LUVOIR mission, the Exoplanet Exploration Program (ExEP) has launched a multi-team technical study: Segmented Coronagraph Design and Analysis (SCDA). The goal of this study is to develop viable coronagraph instrument concepts for a LUVOIR-type mission. Results of the SCDA effort will directly inform the mission concept evaluation being carried out by the LUVOIR Science and Technology Definition Team. The apodized pupil Lyot coronagraph (APLC) is one of several coronagraph design families that the SCDA study is assessing. The APLC is a Lyot-style coronagraph that suppresses starlight through a series of amplitude operations on the on-axis field. Given a suite of seven plausible segmented telescope apertures, we have developed an object-oriented software toolkit to automate the exploration of thousands of APLC design parameter combinations. In the course of exploring this parameter space we have established relationships between APLC throughput and telescope aperture geometry, Lyot stop, inner working angle, bandwidth, and contrast level. In parallel with the parameter space exploration, we have investigated several strategies to improve the robustness of APLC designs to fabrication and alignment errors and integrated a Design Reference Mission framework to evaluate designs with scientific yield metrics.

Effect of oxidant on resputtering of Bi from Bi--Sr--Ca--Cu--O films

International Nuclear Information System (INIS)

Grace, J.M.; McDonald, D.B.; Reiten, M.T.; Olson, J.; Kampwirth, R.T.; Gray, K.E.

1992-01-01

The type and partial pressure of oxidant mixed with argon can affect the selective sputtering of Bi in composite-target, magnetron-sputtered Bi--Sr--Ca--Cu--O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O + 2 , which interacts with the target to produce energetic O - . In contrast, ozone may form lower-energy O - by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y--Ba--Cu--O by others are comparable. Bi in Bi--Sr--Ca--Cu--O behaves as Ba in Y--Ba--Cu--O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi--Sr--Ca--Cu--O is similar to what is observed for Cu in Y--Ba--Cu--O

Sorghum bi-color

African Journals Online (AJOL)

sunny

2014-11-12

Nov 12, 2014 ... Biomass materials require reduction and densification for the purpose of handling and space requirements. Guinea corn (Sorghum bi-color) is a major source of biomass material in the tropic regions. The densification process involves some ... a closed-end die, the temperature and the use of binder.

Effect of a novel motion correction algorithm (SSF) on the image quality of coronary CTA with intermediate heart rates: Segment-based and vessel-based analyses

Energy Technology Data Exchange (ETDEWEB)

Li, Qianwen, E-mail: qianwen18@126.com; Li, Pengyu, E-mail: lipyu818@gmail.com; Su, Zhuangzhi, E-mail: suzhuangzhi@xwh.ccmu.edu.cn; Yao, Xinyu, E-mail: 314985151@qq.com; Wang, Yan, E-mail: wy19851121@126.com; Wang, Chen, E-mail: fskwangchen@gmail.com; Du, Xiangying, E-mail: duxying_xw@163.com; Li, Kuncheng, E-mail: kuncheng.li@gmail.com

2014-11-15

Highlights: • SSF provided better image quality than single-sector and bi-sector reconstruction among the intermediate heart rates (65–75 bpm). • Evidence for the application of prospective ECG-triggered coronary CTA with SSF onto an expanded heart rate range. • Information about the inconsistent effectiveness of SSF among the segments of coronary artery. - Abstract: Purpose: To evaluate the effect of SnapShot Freeze (SSF) reconstruction at an intermediate heart-rate (HR) range (65–75 bpm) and compare this method with single-sector reconstruction and bi-sector reconstruction on segmental and vessel bases in retrospective coronary computed tomography angiography (CCTA). Materials and methods: Retrospective electrocardiogram-gated CCTA was performed on 37 consecutive patients with HR between 65 and 75 bpm using a 64-row CT scanner. Retrospective single-sector reconstruction, bi-sector reconstruction, and SSF were performed for each patient. Multi-phase single-sector reconstruction was performed to select the optimal phase. SSF and bi-sector images were also reconstructed at the optimal phase. The images were interpreted in an intent-to-diagnose fashion by two experienced readers using a 5-point scale, with 3 points as diagnostically acceptable. Image quality among the three reconstruction groups were compared on per-patient, per-vessel, and per-segment bases. Results: The average HR of the enrolled patients was 69.4 ± 2.7 bpm. A total of 111 vessels and 481 coronary segments were assessed. SSF provided significantly higher interpretability of the coronary segments than bi-sector reconstructions. The qualified and excellent rates of SSF (97.9% and 82.3%) were significantly higher than those of single-sector (92.9% and 66.3%) and bi-sector (90.9% and 64.7%) reconstructions. The image quality score (IQS) using SSF was also significantly higher than those of single-sector and bi-sector reconstructions both on per-patient and per-vessel bases. On per-segment

The crystal structure of Cu1.78Bi4.73Se8, an N=3 pavonite homologue with a Cu-for-Bi substitution

DEFF Research Database (Denmark)

Makovicky, Emil; Søtofte, Inger; Karup-Møller, Sven

2006-01-01

Abstract: Cu1.78Bi4.73Se8, synthesized in a dry phase system Cu-Bi-Se at 450 degrees C, is monoclinic, a = 13.759 angstrom, b = 4.168 angstrom, c = 14.683 angstrom, beta = 115.61 degrees, space group C2/m. It is an N = 3 member of the pavonite homologous series, with the composition limits Cu1.96Bi...

Stereo visualization in the ground segment tasks of the science space missions

Science.gov (United States)

Korneva, Natalia; Nazarov, Vladimir; Mogilevsky, Mikhail; Nazirov, Ravil

The ground segment is one of the key components of any science space mission. Its functionality substantially defines the scientific effectiveness of the experiment as a whole. And it should be noted that its outstanding feature (in contrast to the other information systems of the scientific space projects) is interaction between researcher and project information system in order to interpret data being obtained during experiments. Therefore the ability to visualize the data being processed is essential prerequisite for ground segment's software and the usage of modern technological solutions and approaches in this area will allow increasing science return in general and providing a framework for new experiments creation. Mostly for the visualization of data being processed 2D and 3D graphics are used that is caused by the traditional visualization tools capabilities. Besides that the stereo data visualization methods are used actively in solving some tasks. However their usage is usually limited to such tasks as visualization of virtual and augmented reality, remote sensing data processing and suchlike. Low prevalence of stereo visualization methods in solving science ground segment tasks is primarily explained by extremely high cost of the necessary hardware. But recently appeared low cost hardware solutions for stereo visualization based on the page-flip method of views separation. In this case it seems promising to use the stereo visualization as an instrument for investigation of a wide range of problems, mainly for stereo visualization of complex physical processes as well as mathematical abstractions and models. The article is concerned with an attempt to use this approach. It describes the details and problems of using stereo visualization (page-flip method based on NVIDIA 3D Vision Kit, graphic processor GeForce) for display of some datasets of magnetospheric satellite onboard measurements and also in development of the software for manual stereo matching.

Development of Bi-Sb-Te ternary alloy with compositionally graded structure

Energy Technology Data Exchange (ETDEWEB)

Yamamoto, A; Ohta, T

1997-07-01

Compositionally graded p-type Bi-Sb-Te thermoelectric material was synthesized by PIES (Pulverized and Intermixed Elements Sintering) method. The materials consisted of three segmented regions of different alloy composition, i.e., y = 0.8/0.825/0.9 in (Bi{sub 2}Te{sub 3}){sub 1{minus}y} (Sb{sub 2}Te{sub 3}){sub y} system. It was found that the electrical power output of the compositionally graded material was larger than that of the best single composition material when the temperature difference was the designed value.

The effect of oxidant on resputtering of Bi from Bi-Sr-Ca-Cu-O films

Science.gov (United States)

Grace, J. M.; McDonald, D. B.; Reiten, M. T.; Olson, J.; Kampwirth, R. T.; Gray, K. E.

1991-09-01

The type and partial pressure of oxidant mixed with argon can affect the selective resputtering of Bi in composite-target, magnetron-sputtered Bi-Sr-Ca-Cu-O films. Comparative studies using oxygen and ozone show that ozone is a more potent oxidant, as well as a more potent source of resputterers, than is oxygen. Severe resputtering from ozone is significantly reduced by a -40 V potential on the sample block. We suggest that oxygen causes resputtering by forming O2(+)p , which interacts with the target to produce energetic O(-). In contrast, ozone may form lower-energy O(-) by electron impact in the dark space. Negative oxygen ions from the target itself may be responsible for a background resputtering effect. Our results and those found for Y-Ba-Cu-O by others are comparable. Bi in Bi-Sr-Ca-Cu-O behaves as Ba in Y-Ba-Cu-O, with regard to selective resputtering; furthermore, the response of Sr, Ca, and Cu to oxygen in sputtered Bi-Sr-Ca-Cu-O is similar to what is observed for Cu in Y-Ba-Cu-O.

A comparative study of the Aurivillius phase ferroelectrics CaBi 4Ti 4O 15 and BaBi 4Ti 4O 15

Science.gov (United States)

Tellier, J.; Boullay, Ph.; Manier, M.; Mercurio, D.

2004-06-01

The room temperature structures of the four-layer Aurivillius phase ferroelectrics CaBi 4Ti 4O 15 and BaBi 4Ti 4O 15 are determined by means of single crystal X-ray diffraction. Regarding the CaBi 4Ti 4O 15 phase, in agreement with the tolerance factor, a significant deformation of the perovskite blocks is observed. The rotation system of the octahedra is typical from even layer Aurivillius phases and leads to the use of the space group A2 1am. For the BaBi 4Ti 4O 15 phase, only a weak variation with respect to the F2 mm space group can be suggested from single crystal X-ray diffraction. A significant presence of Ba atoms in the [ M2O 2] slabs is confirmed in agreement with the previous works but specific Ba 2+ and Bi 3+ sites have to be considered due to the large difference in bounding requirement of these cations. Possible origins for the ferroelectric relaxor behavior of the Ba-based compound are discussed in view of the presented structural analyses.

DDeveloping and solving a bi-objective joint replenishment problem under storing space constraint

Directory of Open Access Journals (Sweden)

ommolbanin yousefi

2011-03-01

Full Text Available In this research, a bi-objective joint replenishment problem has been developed and solved with the assumption of one restricted resource. The proposed model has a storing space constraint and tries to optimize two objective functions simultaneously. They include minimizing annual holding and setup costs and minimizing annual inventory investment. Then, for solving this problem, a multi-objective genetic algorithm (MOGA has been developed. In order to analyze the algorithm efficiency, its performance has been examined in solving 1600 randomly produced problems using parameters extracted from literature. The findings imply that the proposed algorithm is capable of producing a good set of Pareto optimal solutions. Finally, the application of the problem solving approach and the findings of the proposed algorithm have been illustrated for a special problem, which has been randomly produced.

Annealing-Induced Bi Bilayer on Bi2Te3 Investigated via Quasi-Particle-Interference Mapping.

Science.gov (United States)

Schouteden, Koen; Govaerts, Kirsten; Debehets, Jolien; Thupakula, Umamahesh; Chen, Taishi; Li, Zhe; Netsou, Asteriona; Song, Fengqi; Lamoen, Dirk; Van Haesendonck, Chris; Partoens, Bart; Park, Kyungwha

2016-09-27

Topological insulators (TIs) are renowned for their exotic topological surface states (TSSs) that reside in the top atomic layers, and hence, detailed knowledge of the surface top atomic layers is of utmost importance. Here we present the remarkable morphology changes of Bi2Te3 surfaces, which have been freshly cleaved in air, upon subsequent systematic annealing in ultrahigh vacuum and the resulting effects on the local and area-averaging electronic properties of the surface states, which are investigated by combining scanning tunneling microscopy (STM), scanning tunneling spectroscopy (STS), and Auger electron spectroscopy (AES) experiments with density functional theory (DFT) calculations. Our findings demonstrate that the annealing induces the formation of a Bi bilayer atop the Bi2Te3 surface. The adlayer results in n-type doping, and the atomic defects act as scattering centers of the TSS electrons. We also investigated the annealing-induced Bi bilayer surface on Bi2Te3 via voltage-dependent quasi-particle-interference (QPI) mapping of the surface local density of states and via comparison with the calculated constant-energy contours and QPI patterns. We observed closed hexagonal patterns in the Fourier transform of real-space QPI maps with secondary outer spikes. DFT calculations attribute these complex QPI patterns to the appearance of a "second" cone due to the surface charge transfer between the Bi bilayer and the Bi2Te3. Annealing in ultrahigh vacuum offers a facile route for tuning of the topological properties and may yield similar results for other topological materials.

Radiation Induced Fault Analysis for Wide Temperature BiCMOS Circuits, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — State of the art Radiation Hardened by Design (RHBD) techniques do not account for wide temperature variations in BiCMOS process. Silicon-Germanium BiCMOS process...

Segmental blood pressure after total hip replacement

DEFF Research Database (Denmark)

Gebuhr, Peter Henrik; Soelberg, M; Henriksen, Jens Henrik Sahl

1992-01-01

Twenty-nine patients due to have a total hip replacement had their systemic systolic and segmental blood pressures measured prior to operation and 1 and 6 weeks postoperatively. No patients had signs of ischemia. The segmental blood pressure was measured at the ankle and at the toes. A significant...... drop was found in all pressures 1 week postoperatively. The decrease followed the systemic pressure and was restored to normal after 6 weeks. In a group of six patients with preoperatively decreased ankle pressure, a significant transient further decrease in the ankle-toe gradient pressure was found...... on the operated side. None of the patients had symptoms from the lowered pressure. We conclude that in patients without signs of ischemia, the postoperative segmental pressure decrease is reversible and therefore not dangerous....

Hexamethylenetetramine assisted hydrothermal synthesis of BiPO4 and its electrochemical properties for supercapacitors

Science.gov (United States)

Nithya, V. D.; Kalai Selvan, R.; Vasylechko, Leonid

2015-11-01

The well defined microstructures of BiPO4 were successfully synthesized by the facile hexamethylenetetramine (HMT) assisted hydrothermal method. The low temperature monoclinic BiPO4 structure with space group P21/n, were obtained from X-ray diffraction (XRD) for the pristine and HMT-assisted BiPO4 with 1, 3, 5 and 10 mmole concentration. A transformation from low temperature monazite-type phase to the high temperature SbPO4-type phase of BiPO4 was observed at the 10 mmole concentration. There was a variation in the morphology from polyhedron to octahedra-like and finally into cube shape upon an increase in concentration of HMT. The role of reaction time in the morphology of BiPO4 particles was investigated. The selected area electron diffraction (SAED) pattern elucidated the ordered dot pattern and the calculated d-spacing revealed the formation of BiPO4. An increased specific capacitance of HMT assisted materials (202 F/g) compared with pristine BiPO4 (89 F/g) at 5 mA/cm2 was observed upon morphological variation due to HMT addition.

A NEW FRAMEWORK FOR OBJECT-BASED IMAGE ANALYSIS BASED ON SEGMENTATION SCALE SPACE AND RANDOM FOREST CLASSIFIER

Directory of Open Access Journals (Sweden)

A. Hadavand

2015-12-01

Full Text Available In this paper a new object-based framework is developed for automate scale selection in image segmentation. The quality of image objects have an important impact on further analyses. Due to the strong dependency of segmentation results to the scale parameter, choosing the best value for this parameter, for each class, becomes a main challenge in object-based image analysis. We propose a new framework which employs pixel-based land cover map to estimate the initial scale dedicated to each class. These scales are used to build segmentation scale space (SSS, a hierarchy of image objects. Optimization of SSS, respect to NDVI and DSM values in each super object is used to get the best scale in local regions of image scene. Optimized SSS segmentations are finally classified to produce the final land cover map. Very high resolution aerial image and digital surface model provided by ISPRS 2D semantic labelling dataset is used in our experiments. The result of our proposed method is comparable to those of ESP tool, a well-known method to estimate the scale of segmentation, and marginally improved the overall accuracy of classification from 79% to 80%.

Local and average structure of Mn- and La-substituted BiFeO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Jiang, Bo; Selbach, Sverre M., E-mail: selbach@ntnu.no

2017-06-15

The local and average structure of solid solutions of the multiferroic perovskite BiFeO{sub 3} is investigated by synchrotron X-ray diffraction (XRD) and electron density functional theory (DFT) calculations. The average experimental structure is determined by Rietveld refinement and the local structure by total scattering data analyzed in real space with the pair distribution function (PDF) method. With equal concentrations of La on the Bi site or Mn on the Fe site, La causes larger structural distortions than Mn. Structural models based on DFT relaxed geometry give an improved fit to experimental PDFs compared to models constrained by the space group symmetry. Berry phase calculations predict a higher ferroelectric polarization than the experimental literature values, reflecting that structural disorder is not captured in either average structure space group models or DFT calculations with artificial long range order imposed by periodic boundary conditions. Only by including point defects in a supercell, here Bi vacancies, can DFT calculations reproduce the literature results on the structure and ferroelectric polarization of Mn-substituted BiFeO{sub 3}. The combination of local and average structure sensitive experimental methods with DFT calculations is useful for illuminating the structure-property-composition relationships in complex functional oxides with local structural distortions. - Graphical abstract: The experimental and simulated partial pair distribution functions (PDF) for BiFeO{sub 3}, BiFe{sub 0.875}Mn{sub 0.125}O{sub 3}, BiFe{sub 0.75}Mn{sub 0.25}O{sub 3} and Bi{sub 0.9}La{sub 0.1}FeO{sub 3}.

Spontaneous radiation of a chiral molecule located near a half-space of a bi-isotropic material

Science.gov (United States)

Guzatov, D. V.; Klimov, V. V.; Poprukailo, N. S.

2013-04-01

Analytical expressions for the rate of spontaneous emission from a chiral (optically active) molecule located near a half-space occupied by a chiral (bi-isotropic) material have been obtained and analyzed in detail. It is established that the rates of spontaneous emission from the "right" and "left" enantiomers of molecules occurring near the chiral medium may significantly differ in cases of chiral materials with (i) both negative dielectric permittivity and magnetic permeability (DNG metamaterial) and (ii) negative permeability and positive permittivity (MNG metamaterial). Based on this phenomenon, DMG and MNG metamaterials can be used to create devices capable of separating right and left enantiomers in racemic mixtures.

Spontaneous radiation of a chiral molecule located near a half-space of a bi-isotropic material

Energy Technology Data Exchange (ETDEWEB)

Guzatov, D. V., E-mail: vklimov@sci.lebedev.ru [Yanka Kupala Grodno State University (Belarus); Klimov, V. V., E-mail: klimov256@gmail.com [Russian Academy of Sciences, Lebedev Physical Institute (Russian Federation); Poprukailo, N. S. [Yanka Kupala Grodno State University (Belarus)

2013-04-15

Analytical expressions for the rate of spontaneous emission from a chiral (optically active) molecule located near a half-space occupied by a chiral (bi-isotropic) material have been obtained and analyzed in detail. It is established that the rates of spontaneous emission from the 'right' and 'left' enantiomers of molecules occurring near the chiral medium may significantly differ in cases of chiral materials with (i) both negative dielectric permittivity and magnetic permeability (DNG metamaterial) and (ii) negative permeability and positive permittivity (MNG metamaterial). Based on this phenomenon, DMG and MNG metamaterials can be used to create devices capable of separating right and left enantiomers in racemic mixtures.

Spontaneous radiation of a chiral molecule located near a half-space of a bi-isotropic material

International Nuclear Information System (INIS)

Guzatov, D. V.; Klimov, V. V.; Poprukailo, N. S.

2013-01-01

Analytical expressions for the rate of spontaneous emission from a chiral (optically active) molecule located near a half-space occupied by a chiral (bi-isotropic) material have been obtained and analyzed in detail. It is established that the rates of spontaneous emission from the “right” and “left” enantiomers of molecules occurring near the chiral medium may significantly differ in cases of chiral materials with (i) both negative dielectric permittivity and magnetic permeability (DNG metamaterial) and (ii) negative permeability and positive permittivity (MNG metamaterial). Based on this phenomenon, DMG and MNG metamaterials can be used to create devices capable of separating right and left enantiomers in racemic mixtures.

Structure and phase transition of BiFeO3 cubic micro-particles prepared by hydrothermal method

International Nuclear Information System (INIS)

Zhou, Jian-Ping; Yang, Ruo-Lin; Xiao, Rui-Juan; Chen, Xiao-Ming; Deng, Chao-Yong

2012-01-01

Graphical abstract: Bismuth ferrite (BiFeO 3 ) cubic micro-particles with smooth surfaces were synthesized. BiFeO 3 has a hexagonal perovskite structure with a space group R3c below 370 °C and rhombohedral perovskite structure with a space group R3m below 755 °C, undergoes a phase transition in the temperature range of 755–817 °C to a cubic structure, then decompose to liquid and Fe 2 O 3 above 939 °C. Highlights: ► BiFeO 3 micro-particles with smooth surface were synthesized by hydrothermal method. ► BiFeO 3 enjoys hexagonal structure with well element ratio and chemical valence. ► BiFeO 3 transition from rhombohedral phase to cubic phase lasts 60 °C. -- Abstract: Single-phase bismuth ferrite (BiFeO 3 ) powders were synthesized with a hydrothermal method by controlling the experimental conditions carefully. The powder structure, morphology and composition were characterized by using X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscope, Raman measurement and X-ray photoelectron spectroscopy. The particles change from irregular agglomerations to regular cubes with increasing KOH concentration. The large BiFeO 3 cubic particles enjoy much smooth surfaces with well-matched element ratio (Bi:Fe:O = 1:1:3) and chemical valence (Bi 3+ , Fe 3+ and O 2− ). The high temperature XRD and differential scanning calorimetry show that BiFeO 3 powders have a hexagonal perovskite structure with a space group R3c below 370 °C and a rhombohedral structure with a space group R3m below 755 °C. BiFeO 3 undergoes a phase transition in the temperature range of 755–817 °C from rhombohedral structure to a cubic phase, then decomposes to liquid and Fe 2 O 3 above 939 °C.

On atomic mechanisms governing the oxidation of Bi2Te3

Science.gov (United States)

Music, Denis; Chang, Keke; Schmidt, Paul; Braun, Felix N.; Heller, Martin; Hermsen, Steffen; Pöllmann, Peter J.; Schulzendorff, Till; Wagner, Cedric

2017-12-01

Oxidation of Bi2Te3 (space group R \\overline{3} m) has been investigated using experimental and theoretical means. Based on calorimetry, x-ray photoelectron spectroscopy and thermodynamic modelling, Bi2Te3 is at equilibrium with Bi2O3 and TeO2, whereby the most stable compound is Bi2Te3, followed by Bi2O3. The reactivity of Bi towards oxygen is expected to be higher than that of Te. This notion is supported by density functional theory. The strongest bond is formed between Bi and Te, followed by Bi-O. This gives rise to unanticipated atomic processes. Dissociatively adsorbed oxygen diffuses through Bi and Te basal planes of Bi2Te3(0 0 0 1) and preferably interacts with Bi. The Te termination considerably retards this process. These findings may clarify conflicting literature data. Any basal plane off-cut or Bi terminations trigger oxidation, but a perfect basal cleavage, where only Te terminations are exposed to air, may be stable for a longer period of time. These results are of relevance for applications in which surfaces are of key importance, such as nanostructured Bi2Te3 thermoelectric devices.

Dimensions of Velopharyngeal Space following Maxillary Advancement with Le Fort I Osteotomy Compared to Zisser Segmental Osteotomy: A Cephalometric Study

Directory of Open Access Journals (Sweden)

Furkan Erol Karabekmez

2015-01-01

Full Text Available The objectives of this study are to assess the velopharyngeal dimensions using cephalometric variables of the nasopharynx and oropharynx as well as to compare the Le Fort I osteotomy technique to Zisser’s anterior maxillary osteotomy technique based on patients’ outcomes within early and late postoperative follow-ups. 15 patients with severe maxillary deficiency treated with Le Fort I osteotomy and maxillary segmental osteotomy were assessed. Preoperative, early postoperative, and late postoperative follow-up lateral cephalograms, patient histories, and operative reports are reviewed with a focus on defined cephalometric landmarks for assessing velopharyngeal space dimension and maxillary movement (measured for three different tracing points. A significant change was found between preoperative and postoperative lateral cephalometric measurements regarding the distance between the posterior nasal spine and the posterior pharyngeal wall in Le Fort I osteotomy cases. However, no significant difference was found between preoperative and postoperative measurements in maxillary segmental osteotomy cases regarding the same measurements. The velopharyngeal area calculated for the Le Fort I osteotomy group showed a significant difference between the preoperative and postoperative measurements. Le Fort I osteotomy for advancement of upper jaw increases velopharyngeal space. On the other hand, Zisser’s anterior maxillary segmental osteotomy does not alter the dimension of the velopharyngeal space significantly.

GeoSegmenter: A statistically learned Chinese word segmenter for the geoscience domain

Science.gov (United States)

Huang, Lan; Du, Youfu; Chen, Gongyang

2015-03-01

Unlike English, the Chinese language has no space between words. Segmenting texts into words, known as the Chinese word segmentation (CWS) problem, thus becomes a fundamental issue for processing Chinese documents and the first step in many text mining applications, including information retrieval, machine translation and knowledge acquisition. However, for the geoscience subject domain, the CWS problem remains unsolved. Although a generic segmenter can be applied to process geoscience documents, they lack the domain specific knowledge and consequently their segmentation accuracy drops dramatically. This motivated us to develop a segmenter specifically for the geoscience subject domain: the GeoSegmenter. We first proposed a generic two-step framework for domain specific CWS. Following this framework, we built GeoSegmenter using conditional random fields, a principled statistical framework for sequence learning. Specifically, GeoSegmenter first identifies general terms by using a generic baseline segmenter. Then it recognises geoscience terms by learning and applying a model that can transform the initial segmentation into the goal segmentation. Empirical experimental results on geoscience documents and benchmark datasets showed that GeoSegmenter could effectively recognise both geoscience terms and general terms.

Segmented trapped vortex cavity

Science.gov (United States)

Grammel, Jr., Leonard Paul (Inventor); Pennekamp, David Lance (Inventor); Winslow, Jr., Ralph Henry (Inventor)

2010-01-01

An annular trapped vortex cavity assembly segment comprising includes a cavity forward wall, a cavity aft wall, and a cavity radially outer wall there between defining a cavity segment therein. A cavity opening extends between the forward and aft walls at a radially inner end of the assembly segment. Radially spaced apart pluralities of air injection first and second holes extend through the forward and aft walls respectively. The segment may include first and second expansion joint features at distal first and second ends respectively of the segment. The segment may include a forward subcomponent including the cavity forward wall attached to an aft subcomponent including the cavity aft wall. The forward and aft subcomponents include forward and aft portions of the cavity radially outer wall respectively. A ring of the segments may be circumferentially disposed about an axis to form an annular segmented vortex cavity assembly.

Multi-granularity synthesis segmentation for high spatial resolution Remote sensing images

International Nuclear Information System (INIS)

Yi, Lina; Liu, Pengfei; Qiao, Xiaojun; Zhang, Xiaoning; Gao, Yuan; Feng, Boyan

2014-01-01

Traditional segmentation method can only partition an image in a single granularity space, with segmentation accuracy limited to the single granularity space. This paper proposes a multi-granularity synthesis segmentation method for high spatial resolution remote sensing images based on a quotient space model. Firstly, we divide the whole image area into multiple granules (regions), each region is consisted of ground objects that have similar optimal segmentation scale, and then select and synthesize the sub-optimal segmentations of each region to get the final segmentation result. To validate this method, the land cover category map is used to guide the scale synthesis of multi-scale image segmentations for Quickbird image land use classification. Firstly, the image is coarsely divided into multiple regions, each region belongs to a certain land cover category. Then multi-scale segmentation results are generated by the Mumford-Shah function based region merging method. For each land cover category, the optimal segmentation scale is selected by the supervised segmentation accuracy assessment method. Finally, the optimal scales of segmentation results are synthesized under the guide of land cover category. Experiments show that the multi-granularity synthesis segmentation can produce more accurate segmentation than that of a single granularity space and benefit the classification

Structure and phase transition of BiFeO{sub 3} cubic micro-particles prepared by hydrothermal method

Energy Technology Data Exchange (ETDEWEB)

Zhou, Jian-Ping, E-mail: zhoujp@snnu.edu.cn [College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062 (China); Yang, Ruo-Lin; Xiao, Rui-Juan; Chen, Xiao-Ming [College of Physics and Information Technology, Shaanxi Normal University, Xi’an 710062 (China); Deng, Chao-Yong [Department of Electronic Science, Guizhou University, Guizhou Guiyang 550025 (China)

2012-11-15

Graphical abstract: Bismuth ferrite (BiFeO{sub 3}) cubic micro-particles with smooth surfaces were synthesized. BiFeO{sub 3} has a hexagonal perovskite structure with a space group R3c below 370 °C and rhombohedral perovskite structure with a space group R3m below 755 °C, undergoes a phase transition in the temperature range of 755–817 °C to a cubic structure, then decompose to liquid and Fe{sub 2}O{sub 3} above 939 °C. Highlights: ► BiFeO{sub 3} micro-particles with smooth surface were synthesized by hydrothermal method. ► BiFeO{sub 3} enjoys hexagonal structure with well element ratio and chemical valence. ► BiFeO{sub 3} transition from rhombohedral phase to cubic phase lasts 60 °C. -- Abstract: Single-phase bismuth ferrite (BiFeO{sub 3}) powders were synthesized with a hydrothermal method by controlling the experimental conditions carefully. The powder structure, morphology and composition were characterized by using X-ray diffraction (XRD), scanning electron microscopy, transmission electron microscope, Raman measurement and X-ray photoelectron spectroscopy. The particles change from irregular agglomerations to regular cubes with increasing KOH concentration. The large BiFeO{sub 3} cubic particles enjoy much smooth surfaces with well-matched element ratio (Bi:Fe:O = 1:1:3) and chemical valence (Bi{sup 3+}, Fe{sup 3+} and O{sup 2−}). The high temperature XRD and differential scanning calorimetry show that BiFeO{sub 3} powders have a hexagonal perovskite structure with a space group R3c below 370 °C and a rhombohedral structure with a space group R3m below 755 °C. BiFeO{sub 3} undergoes a phase transition in the temperature range of 755–817 °C from rhombohedral structure to a cubic phase, then decomposes to liquid and Fe{sub 2}O{sub 3} above 939 °C.

Interaction energy of interface dislocation loops in piezoelectric bi-crystals

Directory of Open Access Journals (Sweden)

Jianghong Yuan

2017-03-01

Full Text Available Interface dislocations may dramatically change the electric properties, such as polarization, of the piezoelectric crystals. In this paper, we study the linear interactions of two interface dislocation loops with arbitrary shape in generally anisotropic piezoelectric bi-crystals. A simple formula for calculating the interaction energy of the interface dislocation loops is derived and given by a double line integral along two closed dislocation curves. Particularly, interactions between two straight segments of the interface dislocations are solved analytically, which can be applied to approximate any curved loop so that an analytical solution can be also achieved. Numerical results show the influence of the bi-crystal interface as well as the material orientation on the interaction of interface dislocation loops.

Object-Based Change Detection in Urban Areas: The Effects of Segmentation Strategy, Scale, and Feature Space on Unsupervised Methods

Directory of Open Access Journals (Sweden)

Lei Ma

2016-09-01

Full Text Available Object-based change detection (OBCD has recently been receiving increasing attention as a result of rapid improvements in the resolution of remote sensing data. However, some OBCD issues relating to the segmentation of high-resolution images remain to be explored. For example, segmentation units derived using different segmentation strategies, segmentation scales, feature space, and change detection methods have rarely been assessed. In this study, we have tested four common unsupervised change detection methods using different segmentation strategies and a series of segmentation scale parameters on two WorldView-2 images of urban areas. We have also evaluated the effect of adding extra textural and Normalized Difference Vegetation Index (NDVI information instead of using only spectral information. Our results indicated that change detection methods performed better at a medium scale than at a fine scale where close to the pixel size. Multivariate Alteration Detection (MAD always outperformed the other methods tested, at the same confidence level. The overall accuracy appeared to benefit from using a two-date segmentation strategy rather than single-date segmentation. Adding textural and NDVI information appeared to reduce detection accuracy, but the magnitude of this reduction was not consistent across the different unsupervised methods and segmentation strategies. We conclude that a two-date segmentation strategy is useful for change detection in high-resolution imagery, but that the optimization of thresholds is critical for unsupervised change detection methods. Advanced methods need be explored that can take advantage of additional textural or other parameters.

Impedance spectroscopy of SrBi2Ta2O9 and SrBi2Nb2O9 ceramics correlation with fatigue behavior

International Nuclear Information System (INIS)

Chen, T.; Thio, C.; Desu, S.B.

1997-01-01

In this research, a fatigue model for ferroelectric materials is proposed. The reasons for the electrical fatigue resistance of SrBi 2 Ta 2 O 9 (SBT), SrBi 2 Nb 2 O 9 (SBN), and PbZr 1-x Ti x O 3 (PZT) are discussed in terms of the bulk ionic conductivities of the compounds. To obtain the bulk ionic conductivity of SBT and SBN, we have used impedance spectroscopy which provides an effective method that allows us to separate the individual contributions of bulk, grain boundaries, and electrode-ferroelectric interfaces from the total capacitor impedance. The bulk ionic conductivities of SBT and SBN (∼10 -7 S/cm) are much higher than those of the perovskite ferroelectrics, e.g., PZT (∼10 -11 -10 -10 S/cm). The high ionic conductivities led us to conclude that the good fatigue resistance of SrBi 2 Ta 2 O 9 and SrBi 2 Nb 2 O 9 is due to easy recovery of defects. Specifically, oxygen vacancies entrapped within the capacitors are easily released, resulting in limited space charge buildup and domain wall pinning during the polarization reversal process. However, the oxygen vacancies in PZT are trapped at trap sites to become space charges, resulting in capacitor fatigue. copyright 1997 Materials Research Society

Silent and Efficient Supersonic Bi-Directional Flying Wing

Data.gov (United States)

National Aeronautics and Space Administration — We propose a Phase I study for a novel concept of a supersonic bi-directional (SBiDir) flying wing (FW) that has the potential to revolutionize supersonic flight...

Structures of Bi14WO24 and Bi14MoO24 from neutron powder diffraction data

International Nuclear Information System (INIS)

Ling, C.D.; Withers, R.L.; Thompson, J.G.; Schmid, S.

1999-01-01

The (isomorphous) structures of Bi 14 WO 24 , tetradecabismuth tungsten tetracosaoxide, and Bi 14 MoO 24 , tetradecabismuth molybdenum tetracosaoxide, have been solved and refined using neutron powder diffraction data in the space group I4/m. The metal-atom array is fully ordered in terms of composition, and in terms of atomic positions deviates only slightly from a fluorite-type δ-Bi 2 O 3 -related parent structure. Three independent O-atom sites (accounting for 70 out of 78 O atoms in the unit cell) are also very close to fluorite-type parent positions. The remaining two O-atom sites, which coordinate W, exhibit partial occupancies and displacive disorder, neither of which could be better modelled by lowering of symmetry. The W site is coordinated by four O atoms in highly distorted tetrahedral coordination, the tetrahedron necessarily being orientationally disordered on that site. Nonetheless, the structure appears to be chemically reasonable. (orig.)

Structure of δ-Bi2O3 from density functional theory: A systematic crystallographic analysis

International Nuclear Information System (INIS)

Aidhy, Dilpuneet S.; Sinnott, Susan B.; Wachsman, Eric D.; Phillpot, Simon R.; Nino, Juan C.

2009-01-01

A systematic crystallographic analysis of the and vacancy-ordered structure of cubic δ-Bi 2 O 3 obtained from electronic-structure calculations is presented. The ordering of vacancies leads to a doubling of the unit-cell that results in a 2x2x2 fluorite super-structure, with an associated reduction in its space group symmetry from Fm3-barm to Fm3-bar. The Bi atoms present inside the vacancy-ordered oxygen sublattice have equal Bi-O bond lengths, whereas, those present inside the vacancy-ordered oxygen sublattice have three different pairs of Bi-O bond lengths. The specific ionic displacements and electronic charge configurations also depend on the nature of vacancy ordering in the oxygen sub-lattice. - Graphical abstract: 1/8 of a 2x2x2 δ-Bi 2 O 3 superstructure having Fm3-bar space group. Every oxygen (black) has three possible positions, only one of which is filled either by O1 (red) or O 2 (blue).

Convolutional encoder-decoder for breast mass segmentation in digital breast tomosynthesis

Science.gov (United States)

Zhang, Jun; Ghate, Sujata V.; Grimm, Lars J.; Saha, Ashirbani; Cain, Elizabeth Hope; Zhu, Zhe; Mazurowski, Maciej A.

2018-02-01

Digital breast tomosynthesis (DBT) is a relatively new modality for breast imaging that can provide detailed assessment of dense tissue within the breast. In the domains of cancer diagnosis, radiogenomics, and resident education, it is important to accurately segment breast masses. However, breast mass segmentation is a very challenging task, since mass regions have low contrast difference between their neighboring tissues. Notably, the task might become more difficult in cases that were assigned BI-RADS 0 category since this category includes many lesions that are of low conspicuity and locations that were deemed to be overlapping normal tissue upon further imaging and were not sent to biopsy. Segmentation of such lesions is of particular importance in the domain of reader performance analysis and education. In this paper, we propose a novel deep learning-based method for segmentation of BI-RADS 0 lesions in DBT. The key components of our framework are an encoding path for local-to-global feature extraction, and a decoding patch to expand the images. To address the issue of limited training data, in the training stage, we propose to sample patches not only in mass regions but also in non-mass regions. We utilize a Dice-like loss function in the proposed network to alleviate the class-imbalance problem. The preliminary results on 40 subjects show promise of our method. In addition to quantitative evaluation of the method, we present a visualization of the results that demonstrate both the performance of the algorithm as well as the difficulty of the task at hand.

On-board Payload Data Processing from Earth to Space Segment

Science.gov (United States)

Tragni, M.; Abbattista, C.; Amoruso, L.; Cinquepalmi, L.; Bgongiari, F.; Errico, W.

2013-09-01

Matching the users application requirements with the more and more huge data streaming of the satellite missions is becoming very complex. But we need both of them. To face both the data management (memory availability) and their transmission (band availability) many recent R&D activities are studying the right way to move the data processing from the ground segment to the space segment by the development of the so-called On-board Payload Data Processing (OPDP). The space designer are trying to find new strategies to increase the on board computation capacity and its viability to overcome such limitations, memory and band, focusing the transmission of remote sensing information (not only data) towards their final use. Some typical applications which can benefit of the on board payload data processing include the automatic control of a satellites constellation which can modify its scheduled acquisitions directly on-board and according to the information extracted from the just acquired data, increasing, for example, the capability of monitoring a specific objective (such as oil spills, illegal traffic) with a greater versatility than a traditional ground segment workflow. The authors and their companies can count on a sound experience in design and development of open, modular and compact on-board processing systems. Actually they are involved in a program, the Space Payload Data Processing (SpacePDP) whose main objective is to develop an hardware and a software framework able to perform both the space mission standard tasks (sensors control, mass storage devices management, uplink and downlink) and the specific tasks required by each mission. SpacePDP is an Open and modular Payload Data Processing system, composed of Hardware and Software modules included a SDK. The whole system is characterised by flexible and customizable building blocks that form the system architectures and by a very easy way to be integrated in the missions by the SDK (a development

Automatic segmentation of MR brain images of preterm infants using supervised classification.

Science.gov (United States)

Moeskops, Pim; Benders, Manon J N L; Chiţ, Sabina M; Kersbergen, Karina J; Groenendaal, Floris; de Vries, Linda S; Viergever, Max A; Išgum, Ivana

2015-09-01

Preterm birth is often associated with impaired brain development. The state and expected progression of preterm brain development can be evaluated using quantitative assessment of MR images. Such measurements require accurate segmentation of different tissue types in those images. This paper presents an algorithm for the automatic segmentation of unmyelinated white matter (WM), cortical grey matter (GM), and cerebrospinal fluid in the extracerebral space (CSF). The algorithm uses supervised voxel classification in three subsequent stages. In the first stage, voxels that can easily be assigned to one of the three tissue types are labelled. In the second stage, dedicated analysis of the remaining voxels is performed. The first and the second stages both use two-class classification for each tissue type separately. Possible inconsistencies that could result from these tissue-specific segmentation stages are resolved in the third stage, which performs multi-class classification. A set of T1- and T2-weighted images was analysed, but the optimised system performs automatic segmentation using a T2-weighted image only. We have investigated the performance of the algorithm when using training data randomly selected from completely annotated images as well as when using training data from only partially annotated images. The method was evaluated on images of preterm infants acquired at 30 and 40weeks postmenstrual age (PMA). When the method was trained using random selection from the completely annotated images, the average Dice coefficients were 0.95 for WM, 0.81 for GM, and 0.89 for CSF on an independent set of images acquired at 30weeks PMA. When the method was trained using only the partially annotated images, the average Dice coefficients were 0.95 for WM, 0.78 for GM and 0.87 for CSF for the images acquired at 30weeks PMA, and 0.92 for WM, 0.80 for GM and 0.85 for CSF for the images acquired at 40weeks PMA. Even though the segmentations obtained using training data

The Public Space of “Jogja Fashion Week Carnival” and Cosplay Clothing in Yogyakarta

Directory of Open Access Journals (Sweden)

Deni Setiawan

2015-01-01

Full Text Available The concept of an ideal public space does not just focus on the interests of a particular group or community, but rather focus on the space of social activities that represent each audience or spectator in that society. Arts and cultural activities are part of it; although the concept of public space is still abstract to represent every social individual. However, the presence of public space has created a mediation space for all forms of communication. Mediation space is considered as a crucial feature, not only as a promotional sphere but also as a place to exchange and communicate all forms of ideology, art, and culture. Art activities such as Jogja Fashion Week Carnival and Cosplay clothing performance in public spaces provide opportunities for communities or individuals, to make this activity as a public performance and part of public art. Public art tends to be creative, free, and sometimes not accompanied by a theoretical perspective, as other arts are. Art activities in public spaces which are part of the social and cultural activities are essentially standing on the ideology that have been set up for a particular interest. The interest is disseminated using mass media and advertisment. Audience or public art connoisseur in public spaces should be more intelligent and critical to accept all kinds of art activities and performances. Therefore the performance will have a balanced communication.AbstrakKonsep ruang publik yang ideal tidak saja berbicara kepentingan golongan atau komunitas tertentu, tetapi lebih fokus pada wadah aktivitas sosial yang mewakili setiap pendatang atau penonton. Termasuk didalamnya adalah aktivitas seni dan budaya, walaupun konsep ruang publik masih dapat dikatakan abstrak untuk mewakili setiap individu sosial. Akan tetapi dengan adanya ruang publik telah menciptakan ruang mediasi bagi segala macam bentuk komunikasi. Ruang mediasi ini dipandang penting, tidak saja dijadikan ranah promosi, lebih mendalam adalah

Does increasing the size of bi-weekly samples of records influence results when using the Global Trigger Tool? An observational study of retrospective record reviews of two different sample sizes.

Science.gov (United States)

Mevik, Kjersti; Griffin, Frances A; Hansen, Tonje E; Deilkås, Ellen T; Vonen, Barthold

2016-04-25

To investigate the impact of increasing sample of records reviewed bi-weekly with the Global Trigger Tool method to identify adverse events in hospitalised patients. Retrospective observational study. A Norwegian 524-bed general hospital trust. 1920 medical records selected from 1 January to 31 December 2010. Rate, type and severity of adverse events identified in two different samples sizes of records selected as 10 and 70 records, bi-weekly. In the large sample, 1.45 (95% CI 1.07 to 1.97) times more adverse events per 1000 patient days (39.3 adverse events/1000 patient days) were identified than in the small sample (27.2 adverse events/1000 patient days). Hospital-acquired infections were the most common category of adverse events in both the samples, and the distributions of the other categories of adverse events did not differ significantly between the samples. The distribution of severity level of adverse events did not differ between the samples. The findings suggest that while the distribution of categories and severity are not dependent on the sample size, the rate of adverse events is. Further studies are needed to conclude if the optimal sample size may need to be adjusted based on the hospital size in order to detect a more accurate rate of adverse events. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Capabilities of a Laser Guide Star for a Large Segmented Space Telescope

Science.gov (United States)

Clark, James R.; Carlton, Ashley; Douglas, Ewan S.; Males, Jared R.; Lumbres, Jennifer; Feinberg, Lee; Guyon, Olivier; Marlow, Weston; Cahoy, Kerri L.

2018-01-01

Large segmented mirror telescopes are planned for future space telescope missions such as LUVOIR (Large UV Optical Infrared Surveyor) to enable the improvement in resolution and contrast necessary to directly image Earth-like exoplanets, in addition to making contributions to general astrophysics. The precision surface control of these complex, large optical systems, which may have over a hundred meter-sized segments, is a challenge. Our initial simulations show that imaging a star of 2nd magnitude or brighter with a Zernike wavefront sensor should relax the segment stability requirements by factors between 10 and 50 depending on the wavefront control strategy. Fewer than fifty stars brighter than magnitude 2 can be found in the sky. A laser guide star (LGS) on a companion spacecraft will allow the telescope to target a dimmer science star and achieve wavefront control to the required stability without requiring slew or repointing maneuvers.We present initial results for one possible mission architecture, with a LGS flying at 100,000 km range from the large telescope in an L2 halo orbit, using a laser transmit power of 8 days) for an expenditure of system, it can be accommodated in a 6U CubeSat bus, but may require an extended period of time to transition between targets and match velocities with the telescope (e.g. 6 days to transit 10 degrees). If the LGS uses monopropellant propulsion, it must use at least a 27U bus to achieve the the same delta-V capability, but can transition between targets much more rapidly (flight are being refined. A low-cost prototype mission (e.g. between a small satellite in LEO and an LGS in GEO) to validate the feasibility is in development.

AGOR 28: SIO Shipyard Representative Bi-Weekly Progress Report

Science.gov (United States)

2016-06-18

Sally Ride. • Two full 20-foot IOL shipping containers scheduled for delivery DCI on Monday. • Spares Load out scheduled for next week. 4. Operator...the silty water. 2 • Anchor Windlass – Design using “ulster” chain guide is progressing. Yesterday’s development regarding foreign chain...J-1 at sustained speed. See Airborne Noise Survey Report (DI-032-006) for more information (Delete after RFW approved) 1137 HVAC - There were no

Bi-Force

DEFF Research Database (Denmark)

Sun, Peng; Speicher, Nora K; Röttger, Richard

2014-01-01

of pairwise similarities. We first evaluated the power of Bi-Force to solve dedicated bicluster editing problems by comparing Bi-Force with two existing algorithms in the BiCluE software package. We then followed a biclustering evaluation protocol in a recent review paper from Eren et al. (2013) (A...... comparative analysis of biclustering algorithms for gene expressiondata. Brief. Bioinform., 14:279-292.) and compared Bi-Force against eight existing tools: FABIA, QUBIC, Cheng and Church, Plaid, BiMax, Spectral, xMOTIFs and ISA. To this end, a suite of synthetic datasets as well as nine large gene expression...

Design and Fabrication of High Gain Multi-element Multi-segment Quarter-sector Cylindrical Dielectric Resonator Antenna

Science.gov (United States)

Ranjan, Pinku; Gangwar, Ravi Kumar

2017-12-01

A novel design and analysis of quarter cylindrical dielectric resonator antenna (q-CDRA) with multi-element and multi-segment (MEMS) approach has been presented. The MEMS q-CDRA has been designed by splitting four identical quarters from a solid cylinder and then multi-segmentation approach has been utilized to design q-CDRA. The proposed antenna has been designed for enhancement in bandwidth as well as for high gain. For bandwidth enhancement, multi-segmentation method has been explained for the selection of dielectric constant of materials. The performance of the proposed MEMS q-CDRA has been demonstrated with design guideline of MEMS approach. To validate the antenna performance, three segments q-CDRA has been fabricated and analyzed practically. The simulated results have been in good agreement with measured one. The MEMS q-CDRA has wide impedance bandwidth (|S11|≤-10 dB) of 133.8 % with monopole-like radiation pattern. The proposed MEMS q-CDRA has been operating at TM01δ mode with the measured gain of 6.65 dBi and minimum gain of 4.5 dBi in entire operating frequency band (5.1-13.7 GHz). The proposed MEMS q-CDRA may find appropriate applications in WiMAX and WLAN band.

Local and average structure of Mn- and La-substituted BiFeO3

Science.gov (United States)

Jiang, Bo; Selbach, Sverre M.

2017-06-01

The local and average structure of solid solutions of the multiferroic perovskite BiFeO3 is investigated by synchrotron X-ray diffraction (XRD) and electron density functional theory (DFT) calculations. The average experimental structure is determined by Rietveld refinement and the local structure by total scattering data analyzed in real space with the pair distribution function (PDF) method. With equal concentrations of La on the Bi site or Mn on the Fe site, La causes larger structural distortions than Mn. Structural models based on DFT relaxed geometry give an improved fit to experimental PDFs compared to models constrained by the space group symmetry. Berry phase calculations predict a higher ferroelectric polarization than the experimental literature values, reflecting that structural disorder is not captured in either average structure space group models or DFT calculations with artificial long range order imposed by periodic boundary conditions. Only by including point defects in a supercell, here Bi vacancies, can DFT calculations reproduce the literature results on the structure and ferroelectric polarization of Mn-substituted BiFeO3. The combination of local and average structure sensitive experimental methods with DFT calculations is useful for illuminating the structure-property-composition relationships in complex functional oxides with local structural distortions.

A Phase I Dose-Escalation Study of Antibody BI-505 in Relapsed/Refractory Multiple Myeloma

DEFF Research Database (Denmark)

Hansson, Markus; Gimsing, Peter; Badros, Ashraf

2015-01-01

PURPOSE: This multicenter, first-in-human study evaluated safety, tolerability, pharmacokinetics, and pharmacodynamics of BI-505, a human anti-ICAM-1 monoclonal antibody, in advanced relapsed/refractory multiple myeloma patients. EXPERIMENTAL DESIGN: BI-505 was given intravenously, every 2 weeks...... generally mild to moderate, and those attributed to study medication were mostly limited to the first dose and manageable with premedication and slower infusion. No maximum tolerated dose was identified. BI-505's half-life increased with dose while clearance decreased, suggesting target-mediated clearance...

Pneumocephalus with BiPAP use after transsphenoidal surgery☆,☆☆,★

Science.gov (United States)

Kopelovich, Jonathan C.; de la Garza, Gabriel O.; Greenlee, Jeremy D.W.; Graham, Scott M.; Udeh, Chiedozie I.; O'Brien, Erin K.

2013-01-01

While the benefits of continuous positive airway pressure (CPAP) or bilevel positive airway pressure (BiPAP) for patients with obstructive sleep apnea are well described, reports in the literature of complications from its use are rare. A patient who received postoperative BiPAP after undergoing transsphenoidal craniopharyngioma resection developed severe pneumocephalus and unplanned intensive care unit admission. Although the pneumocephalus resolved with conservative management over two weeks, we propose caution in the use of CPAP postoperatively in patients undergoing procedures of the head and neck. PMID:22626688

Synthesis, crystal structure, and physical properties of the Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8} phases

Energy Technology Data Exchange (ETDEWEB)

Forbes, Scott; Yuan, Fang [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada); Kosuda, Kosuke; Kolodiazhnyi, Taras [Institute for Materials Science, 1-1 Namiki, Tsukuba, Ibaraki 305-0044 (Japan); Mozharivskyj, Yurij, E-mail: mozhar@mcmaster.ca [Department of Chemistry and Chemical Biology, McMaster University, 1280 Main Street West, Hamilton, Ontario, Canada L8S 4M1 (Canada)

2016-01-15

The second and third known rare-earth bismuthide oxides, Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8}, have been discovered via high temperature reactions at 1300 °C. Like its Gd–Sb–O counterparts, the Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8} phases crystallize in the monoclinic C2/m space group, with the latter containing disordered Bi atoms along the b direction of the unit cell. Unlike the RE{sub 8}Sb{sub 3}O{sub 8} series, the formation of the Gd{sub 3}BiO{sub 3} phase does not necessarily precede the formation of Gd{sub 8}Bi{sub 3}O{sub 8}, which is likely due to the difficulty of accommodating bismuth in the RE–O framework due to its larger size. Physical property measurements performed on a pure Gd{sub 8}Bi{sub 3}O{sub 8} sample reveal semiconducting behavior. Although electronic structure calculations predict metallic behavior due to an unbalanced electron count, the semiconducting behavior originates from the Anderson localization of the Bi p states near the Fermi level as a result of atomic disorder. - Graphical abstract: Reaction of GdBi and Gd{sub 2}O{sub 3} at high temperatures yields Gd–Bi–O phases. - Highlights: • Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8}, the second and third rare-earth bismuthide oxides, have been discovered. • Gd{sub 3}BiO{sub 3} and Gd{sub 8}Bi{sub 3}O{sub 8} are isostructural with RE{sub 3}SbO{sub 3} and RE{sub 8}Sb{sub 3}O{sub 8}. • Gd{sub 8}Bi{sub 3}O{sub 8} displays semiconducting behavior despite an unbalanced electron count. • Anderson localization of Bi p states results in semiconducting behavior in Gd{sub 8}Bi{sub 3}O{sub 8}.

MDCT urography: experience with a bi-phasic excretory phase examination protocol

International Nuclear Information System (INIS)

Meindl, Thomas; Coppenrath, Eva; Degenhart, Christoph; Reiser, Maximilian F.; Mueller-Lisse, Ullrich G.; Mueller-Lisse, Ulrike L.

2007-01-01

The benefit of multidetector computed tomographic urography (MDCTU) for visualising early and late excretory phase (EP) upper urinary tract (UUT) opacification has been studied. UUT opacification was retrospectively evaluated in 45 bi-phasic four-row MDCTU examinations. The UUT was divided into intrarenal collecting system (IRCS), proximal, middle and distal ureter. Two independent readers rated opacification: 1, none; 2, partial; 3, complete. Numbers of segments and percentages of UUTs at each score were calculated for each EP and two EPs combined. Results of a single EP and of combined EPs were compared by Wilcoxon matched-pairs signed-ranks. IRCS and proximal ureter were at least partially opacified in each EP in >95%. The middle ureter was at least partially opacified in the early and late EP in 85% and 93%, respectively. The distal ureter was opacified in 65% (49/75) in the early EP and in 78% (59/75) in the late EP. Combining two EPs, non-opacified distal segments decreased to 9% (7/75). Significant improvement between a single EP and combining two EPs were found for the middle and distal ureter (P < 0.03). Bi-phasic MDCTU substantially improved opacification of the middle and distal ureter. IRCS and proximal ureter are reliably opacified with one EP. (orig.)

Bi-induced band gap reduction in epitaxial InSbBi alloys

Energy Technology Data Exchange (ETDEWEB)

Rajpalke, M. K.; Linhart, W. M.; Birkett, M.; Alaria, J.; Veal, T. D., E-mail: T.Veal@liverpool.ac.uk [Stephenson Institute for Renewable Energy and Department of Physics, School of Physical Sciences, University of Liverpool, Liverpool L69 7ZF (United Kingdom); Yu, K. M. [Materials Sciences Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 94720 (United States); Bomphrey, J. J.; Jones, T. S.; Ashwin, M. J., E-mail: M.J.Ashwin@warwick.ac.uk [Department of Chemistry, University of Warwick, Coventry CV4 7AL (United Kingdom); Sallis, S.; Piper, L. F. J. [Materials Science and Engineering, Binghamton University, Binghamton, New York 13902 (United States)

2014-11-24

The properties of molecular beam epitaxy-grown InSb{sub 1−x}Bi{sub x} alloys are investigated. Rutherford backscattering spectrometry shows that the Bi content increases from 0.6% for growth at 350 °C to 2.4% at 200 °C. X-ray diffraction indicates Bi-induced lattice dilation and suggests a zinc-blende InBi lattice parameter of 6.626 Å. Scanning electron microscopy reveals surface InSbBi nanostructures on the InSbBi films for the lowest growth temperatures, Bi droplets at intermediate temperatures, and smooth surfaces for the highest temperature. The room temperature optical absorption edge was found to change from 172 meV (7.2 μm) for InSb to ∼88 meV (14.1 μm) for InSb{sub 0.976}Bi{sub 0.024}, a reduction of ∼35 meV/%Bi.

Open segmental fracture of both bone forearm and dislocation of ipsilateral elbow with extruded middle segment radius

Directory of Open Access Journals (Sweden)

Pawan Kumar

2013-01-01

Full Text Available Extruded middle segment of radius with open segmental fracture both bone forearm and dislocation of ipsilateral elbow is a rare injury. A 12-year-old child presented to us within 4 hours following fall from tree. The child′s mother was carrying a 12-cm-long extruded soiled segment of radius. The extruded bone was thoroughly washed. The medullary cavity was properly syringed with antiseptic solution. The bone was autoclaved and put in the muscle plane of the distal forearm after debridement of the wound. After 5 days, a 2.5-mm K-wire was introduced by retrograde method into the proximal radius by passing through the extruded segment. Another 2.5-mm K-wire was passed in ulna. The limb was evaluated clinicoradiologically every 2 weeks. The wound was healed by primary intention. At 4 months, the reposed bone appeared less dense radiologically and K-wire seemed to be out of the bone. In the subsequent months, the roentgenograms show remodeling of the extruded fragment. After 20 weeks, the K-wires were removed (first ulnar and then radial. Complete union was achieved with full range of movement except loss of few degrees of extension of elbow and thumb. This case is reported to show a good outcome following successful incorporation of an extruded segment of radius in an open fracture.

Stark broadening of several Bi IV spectral lines of astrophysical interest

Science.gov (United States)

Colón, C.; Moreno-Díaz, C.; de Andrés-García, I.; Alonso-Medina, A.

2017-09-01

The presence of spectral lines of bismuth in stellar atmospheres has been reported in different stars. The anomalous values of the spectral intensities of Bi II and Bi III, compared to the theoretical Local Termodinamic Equilibrium (LTE) standards of Bi I/Bi II/Bi III, have been reported in the spectra obtained with the High Resolution Spectrograph of the Hubble/Goddard Space Telescope in the chemically peculiar stars HgMn stars χ Lupi and HR 7775. Spectral lines of 1436.8, 1902.3, 2630.9 and 2936.7 Å of Bi II and 1423.4 Å of Bi III were reported and their relative intensities were measured in these studies Litzén & Wahlgren 2002. These lines are overlapped with spectral lines of 1437.65, 2630.1 and 2937.1 Å of Bi IV. A study of the Stark broadening parameters of Bi IV spectral lines can help to study these overlaps. In this paper, using the Griem semi-empirical approach, we report calculated values of the Stark parameters for 64 spectral lines of Bi IV. The matrix elements used in these calculations have been determined from 17 configurations of Bi IV. They were calculated using the cowan code including core polarization effects. Data are displayed for an electron density of 1017 cm-3 and temperatures T = 10 000-160 000 K. Also calculated radiative lifetimes for 12 levels with experimental lifetime are presented, in order to test the goodness of our calculations. Theoretical trends of the Stark width and shift parameters versus the temperature for spectral lines of astrophysical interest are displayed.

Colour application on mammography image segmentation

Science.gov (United States)

Embong, R.; Aziz, N. M. Nik Ab.; Karim, A. H. Abd; Ibrahim, M. R.

2017-09-01

The segmentation process is one of the most important steps in image processing and computer vision since it is vital in the initial stage of image analysis. Segmentation of medical images involves complex structures and it requires precise segmentation result which is necessary for clinical diagnosis such as the detection of tumour, oedema, and necrotic tissues. Since mammography images are grayscale, researchers are looking at the effect of colour in the segmentation process of medical images. Colour is known to play a significant role in the perception of object boundaries in non-medical colour images. Processing colour images require handling more data, hence providing a richer description of objects in the scene. Colour images contain ten percent (10%) additional edge information as compared to their grayscale counterparts. Nevertheless, edge detection in colour image is more challenging than grayscale image as colour space is considered as a vector space. In this study, we implemented red, green, yellow, and blue colour maps to grayscale mammography images with the purpose of testing the effect of colours on the segmentation of abnormality regions in the mammography images. We applied the segmentation process using the Fuzzy C-means algorithm and evaluated the percentage of average relative error of area for each colour type. The results showed that all segmentation with the colour map can be done successfully even for blurred and noisy images. Also the size of the area of the abnormality region is reduced when compare to the segmentation area without the colour map. The green colour map segmentation produced the smallest percentage of average relative error (10.009%) while yellow colour map segmentation gave the largest percentage of relative error (11.367%).

An earthworm-like actuator using segmented solenoids

International Nuclear Information System (INIS)

Shin, Bu Hyun; Choi, Seung-Wook; Lee, Seung-Yop; Bang, Young-Bong

2011-01-01

A biomimetic actuator is developed using four segmented solenoids mimicking earthworm locomotion. The proposed actuator not only has a simple structure composed of cores and coils, but also enables bi-directional actuation and high speed locomotion regardless of friction conditions. We have implemented theoretical analysis to design the optimal profiles of input current signal for maximum speed and predict the output force and stroke. Experiments using a prototype show that the earthworm-like actuator travels with a speed above 60 mm s −1 regardless of friction conditions

Integrated Bi2O3 nanostructure modified with Au nanoparticles for enhanced photocatalytic activity under visible light irradiation

Directory of Open Access Journals (Sweden)

Hankwon Lim

2017-06-01

Full Text Available An integrated Bi2O3 (i-Bi2O3 nanostructure with a particle size 10 nm inducing agglomerated structure were synthesized by dissolving bismuth nitrate pentahydrate in diethylene glycol at 180 °C with post heat treatment. The prepared i-Bi2O3 nanostructures were employed for the construction of Au/i-Bi2O3 composite system and characterized by X-ray diffraction pattern, UV–visible diffuse reflectance spectroscopy (DRS, and transmission electron microscopy, X-ray photoemission spectroscopy (XPS and Energy dispersive X-ray spectroscopy (EDS. The i-Bi2O3 nanostructure and Au/i-Bi2O3 composite system were found to exhibit high photocatalytic activity than commercial Bi2O3 in decomposing salicylic acid under visible light irradiation. The high catalytic activity of i-Bi2O3 nanostructure was deduced to be caused by charge separation facilitated by electron hopping between the particles within the integrated structure and space-charge separation between i-Bi2O3 and Au. The charge separation behavior in i-Bi2O3 nanostructure was further bolstered by comparing the measured. OH radical produced in the solution with i-Bi2O3 nanostructure, commercial Bi2O3 and Au/i-Bi2O3 composite which readily react with 1,4-terephthalic acid (TA inducing 2-hydroxy terephthalic acid (TAOH that shows unique fluorescence peak at 426 nm. The space-charge separation between i-Bi2O3 and Au was confirmed by measuring the electron spin resonance (ESR spectra.

Color image Segmentation using automatic thresholding techniques

International Nuclear Information System (INIS)

Harrabi, R.; Ben Braiek, E.

2011-01-01

In this paper, entropy and between-class variance based thresholding methods for color images segmentation are studied. The maximization of the between-class variance (MVI) and the entropy (ME) have been used as a criterion functions to determine an optimal threshold to segment images into nearly homogenous regions. Segmentation results from the two methods are validated and the segmentation sensitivity for the test data available is evaluated, and a comparative study between these methods in different color spaces is presented. The experimental results demonstrate the superiority of the MVI method for color image segmentation.

Dispersion interactions between neighboring Bi atoms in (BiH3 )2 and Te(BiR2 )2.

Science.gov (United States)

Haack, Rebekka; Schulz, Stephan; Jansen, Georg

2018-03-13

Triggered by the observation of a short Bi⋯Bi distance and a BiTeBi bond angle of only 86.6° in the crystal structure of bis(diethylbismuthanyl)tellurane quantum chemical computations on interactions between neighboring Bi atoms in Te(BiR 2 ) 2 molecules (R = H, Me, Et) and in (BiH 3 ) 2 were undertaken. Bi⋯Bi distances atoms were found to significantly shorten upon inclusion of the d shells of the heavy metal atoms into the electron correlation treatment, and it was confirmed that interaction energies from spin component-scaled second-order Møller-Plesset theory (SCS-MP2) agree well with coupled-cluster singles and doubles theory including perturbative triples (CCSD(T)). Density functional theory-based symmetry-adapted perturbation theory (DFT-SAPT) was used to study the anisotropy of the interplay of dispersion attraction and steric repulsion between the Bi atoms. Finally, geometries and relative stabilities of syn-syn and syn-anti conformers of Te(BiR 2 ) 2 (R = H, Me, Et) and interconversion barriers between them were computed. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

In vitro quantification of the performance of model-based mono-planar and bi-planar fluoroscopy for 3D joint kinematics estimation.

Science.gov (United States)

Tersi, Luca; Barré, Arnaud; Fantozzi, Silvia; Stagni, Rita

2013-03-01

Model-based mono-planar and bi-planar 3D fluoroscopy methods can quantify intact joints kinematics with performance/cost trade-off. The aim of this study was to compare the performances of mono- and bi-planar setups to a marker-based gold-standard, during dynamic phantom knee acquisitions. Absolute pose errors for in-plane parameters were lower than 0.6 mm or 0.6° for both mono- and bi-planar setups. Mono-planar setups resulted critical in quantifying the out-of-plane translation (error bi-planar in quantifying the rotation along bone longitudinal axis (error bi-planar (error comparable to bi-planar, but with halved computational costs, halved segmentation time and halved ionizing radiation dose. Bi-planar analysis better compensated for the out-of-plane uncertainty that is differently propagated to relative kinematics depending on the setup. To take its full benefits, the motion task to be investigated should be designed to maintain the joint inside the visible volume introducing constraints with respect to mono-planar analysis.

A comprehensive segmentation analysis of crude oil market based on time irreversibility

Science.gov (United States)

Xia, Jianan; Shang, Pengjian; Lu, Dan; Yin, Yi

2016-05-01

In this paper, we perform a comprehensive entropic segmentation analysis of crude oil future prices from 1983 to 2014 which used the Jensen-Shannon divergence as the statistical distance between segments, and analyze the results from original series S and series begin at 1986 (marked as S∗) to find common segments which have same boundaries. Then we apply time irreversibility analysis of each segment to divide all segments into two groups according to their asymmetry degree. Based on the temporal distribution of the common segments and high asymmetry segments, we figure out that these two types of segments appear alternately and do not overlap basically in daily group, while the common portions are also high asymmetry segments in weekly group. In addition, the temporal distribution of the common segments is fairly close to the time of crises, wars or other events, because the hit from severe events to oil price makes these common segments quite different from their adjacent segments. The common segments can be confirmed in daily group series, or weekly group series due to the large divergence between common segments and their neighbors. While the identification of high asymmetry segments is helpful to know the segments which are not affected badly by the events and can recover to steady states automatically. Finally, we rearrange the segments by merging the connected common segments or high asymmetry segments into a segment, and conjoin the connected segments which are neither common nor high asymmetric.

Application of a bi-modal PBR nuclear propulsion and power system to military missions

Science.gov (United States)

Venetoklis, Peter S.

1995-01-01

The rapid proliferation of arms technology and space access combined with current economic realities in the United States are creating ever greater demands for more capable space-based military assets. The paper illustrates that bi-modal nuclear propulsion and power based on the Particle Bed Reactor (PBR) is a high-leverage tehcnology that can maximize utility while minimizing cost. Mission benefits offered by the bi-modal PBR, including enhanced maneuverability, lifetime, survivability, payload power, and operational flexibility, are discussed. The ability to deliver desired payloads on smaller boosters is also illustrated. System descriptions and parameters for 10 kWe and 100 kWe power output levels are summarized. It is demonstrated via design exercise that bi-modal PBR dramtically enhances performance of a military satellite in geosynchronous orbit, increasing payload mass, payload power, and maneuverability.

New classes of bi-axially symmetric solutions to four-dimensional Vasiliev higher spin gravity

Energy Technology Data Exchange (ETDEWEB)

Sundell, Per; Yin, Yihao [Departamento de Ciencias Físicas, Universidad Andres Bello,Republica 220, Santiago de Chile (Chile)

2017-01-11

We present new infinite-dimensional spaces of bi-axially symmetric asymptotically anti-de Sitter solutions to four-dimensional Vasiliev higher spin gravity, obtained by modifications of the Ansatz used in https://arxiv.org/abs/1107.1217, which gave rise to a Type-D solution space. The current Ansatz is based on internal semigroup algebras (without identity) generated by exponentials formed out of the bi-axial symmetry generators. After having switched on the vacuum gauge function, the resulting generalized Weyl tensor is given by a sum of generalized Petrov type-D tensors that are Kerr-like or 2-brane-like in the asymptotic AdS{sub 4} region, and the twistor space connection is smooth in twistor space over finite regions of spacetime. We provide evidence for that the linearized twistor space connection can be brought to Vasiliev gauge.

Facile synthesis of Bi/BiOCl composite with selective photocatalytic properties

International Nuclear Information System (INIS)

Chen, Dongling; Zhang, Min; Lu, Qiuju; Chen, Junfang; Liu, Bitao; Wang, Zhaofeng

2015-01-01

This paper presents a novel and facile method to fabricate Bi/BiOCl composites with dominant (001) facets in situ via a microwave reduction route. Different characterization techniques, including X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), transmission scanning electron microscopy (TEM), UV–vis diffuse reflectance spectrometry (DRS), X-ray photoelectron spectroscopy (XPS), electron spin resonance spectroscopy (ESR), cathodoluminescence spectrum (CL), and lifetime, have been employed to investigate the structure, optical and electrical properties of the Bi/BiOCl composites. The experimental results show that the introduction of Bi particles can efficiently enhance the photocatalytic performance of BiOCl for the degradation of several dyes under ultraviolet (UV) light irradiation, especially for negative charged methyl orange (MO). Unlike the UV photocatalytic performance, such Bi/BiOCl composite shows higher degradation efficiency towards rhodamine B (RhB) than MO and methylene blue (MB) under visible light irradiation. This special photocatalytic performance can be ascribed to the synergistic effect between oxygen vacancies and Bi particles. This work provides new insights about the photodegradation mechanisms of MO, MB and RhB under UV and visible light irradiation, which would be helpful to guide the selection of an appropriate catalyst for other pollutants. - Highlights: • Bi/BiOCl composites were synthesized via a microwave reduction. • Tunable selectivity photocatalytic activity can be achieved. • Photodegradation mechanism under UV and visible light were proposed

Stability of the anterior maxillary segment and teeth after segmental le fort I osteotomy and postoperative skeletal elastic fixation with or without occlusal splint

DEFF Research Database (Denmark)

Blæhr, Tue Lindberg; Jensen, Thomas; Due, Karen Margrethe

2014-01-01

OBJECTIVES: To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. MATERIAL AND METHODS: 29 consecutive patients underwent segmental Le Fort I...... osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A) or dismounted perioperatively (group B). Changes in landmarks and reference planes between the two timepoints were estimated on lateral.......83 to 1.69°). There was no statistically significant difference in stability between the two groups at the P value 0.05. CONCLUSIONS: The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment...

Bismuth-boron multiple bonding in BiB_2O"- and Bi_2B"-

International Nuclear Information System (INIS)

Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng

2017-01-01

Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB_2O"- and Bi_2B"-, containing triple and double B-Bi bonds are presented. The BiB_2O"- and Bi_2B"- clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB_2O"- ([Bi≡B-B≡O]"-) and Bi_2B"- ([Bi=B=Bi]"-), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Bubble Formation within Filaments of Melt-Processed Bi2212 wires and its strongly negative effect on the Critical Current Density

CERN Document Server

Kametani, F; Jiang, J; Scheuerlein, C; Malagoli, A; Di Michiel, M; Huang, Y; Miao, H; Parrell, J A; Hellstrom, E E; Larbalestier, D C

2011-01-01

Most studies of Bi2Sr2CaCu2Ox (Bi2212) show that the critical current density Jc is limited by the connectivity of the filaments, but what determines the connectivity is still elusive. Here we report on the role played by filament porosity in limiting Jc. By a microstructural investigation of wires quenched from the melt state, we find that porosity in the unreacted wire agglomerates into bubbles that segment the Bi2212 melt within the filaments into discrete sections. These bubbles do not disappear during subsequent processing because they are only partially filled by Bi2212 grains as the Bi2212 forms on cooling. Correlating the microstructure of quenched wires to their final, fully processed Jc values shows an inverse relation between Jc and bubble density. Bubbles are variable between conductors and perhaps from sample to sample, but they occur frequently and almost completely fill the filament diameter, so they exert a strongly variable but always negative effect on Jc. Bubbles reduce the continuous Bi221...

The modulation and reconstruction of a BiO layer of cuprate Bi2212

International Nuclear Information System (INIS)

Fan Wei; Zeng, Z

2011-01-01

Studies based on ab initio density functional theory show that the modulated structures of BiO surfaces of cuprate Bi2212 superconductors are spontaneously formed and closely related to the reconstructions of BiO surfaces. The reconstructions of BiO layers occur both on the surface and in the bulk, accompanied with the formations of BiO-zigzag chains and Bi 2 O 2 quadrilaterals. The structural modulations of the BiO surface are along the b axis, perpendicular to the BiO-zigzag chains along the a axis. Our calculations provide a unified understanding of the formation of modulating structures in Bi2212. Another interesting result is that electronic structures of BiO surfaces are significantly influenced by the CuO 2 layer beneath because of the structural modulations and reconstructions.

Developments of high strength Bi-containing Sn0.7Cu lead-free solder alloys prepared by directional solidification

Energy Technology Data Exchange (ETDEWEB)

Hu, Xiaowu, E-mail: xwhmaterials@aliyun.com [School of Mechanical Electrical Engineering, Nanchang University, Nanchang 330031 (China); Li, Yulong [School of Mechanical Electrical Engineering, Nanchang University, Nanchang 330031 (China); Liu, Yi [School of Materials Science and Engineering, Nanchang University, Nanchang 330031 (China); Min, Zhixian [China Electronics Technology Group Corporation No. 38 Research Institute, Hefei 230088 (China)

2015-03-15

Highlights: • The Sn0.7Cu–xBi solder alloys were directionally solidified. • Both spacing and diameter of fibers decreased with increasing solidification rate. • The UTS and YS first increased with increased solidification rate, then decreased. • The UTS and YS of Sn0.7Cu–xBi first increased with increased Bi content. - Abstract: Bi-containing Sn0.7Cu (SC) eutectic solder alloys were prepared and subjected to directional solidification, through which new types of fiber reinforced eutectic composites were generated. The influences of Bi addition on the microstructures and tensile properties of directionally solidified (DS) Bi-containing eutectic SC lead-free solder alloys have been investigated by using differential scanning calorimetry (DSC), scanning electron microscopy (SEM), energy dispersive spectrometry (EDS) and a tensile testing machine. The experimental results showed that addition of Bi could effectively reduce both the melting temperature and undercooling of SC solder alloy. The microstructures of DS SC–xBi solder alloys were composed of Sn-rich phase (β) and Cu{sub 6}Sn{sub 5} fiber. No other intermetallic compounds (IMCs) with Bi content were observed in the solder matrix for SC solder alloys with various Bi contents. Both fiber spacing and diameter all decreased gradually with increasing growth rate and/or Bi content. Besides, the regularity of Cu{sub 6}Sn{sub 5} fibers alignment also decreased with increasing growth rate, too. The tensile strengths of the SC–xBi eutectic solder alloys varied parabolically with growth rate (R). When R was 60 μm/s, maximum tensile strengths of 43.8, 55.2 and 56.37 MPa were reached for SC, SC0.7Bi and SC1.3Bi solder alloys. A comparison of tensile strength of SC, SC0.7Bi and SC1.3Bi with the same R indicated that the tensile strength increased with increasing Bi content, which was attributed to the presence of Bi and its role in refining microstructure and solid solution strengthening.

Novel Bi/BiOBr/AgBr composite microspheres: Ion exchange synthesis and photocatalytic performance

Science.gov (United States)

Lyu, Jianchang; Li, Zhenlu; Ge, Ming

2018-06-01

Novel Bi/BiOBr/AgBr composite microspheres were prepared by a rational in situ ion exchange reaction between Bi/BiOBr microspheres and AgNO3. The characteristic of the as-obtained ternary microspheres was tested by X-ray diffraction (XRD), energy dispersive X-ray spectrometer (EDS), scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), UV-vis diffuse reflectance spectroscopy (UV-vis DRS) and photoluminescence (PL). Under visible light irradiation, Bi/BiOBr/AgBr microspheres exhibited an excellent photocatalytic efficiency for rhodamine B (RhB) degradation, which was about 1.4 and 4.9 times as high as that of Bi/BiOBr and BiOBr/AgBr, demonstrating that the highest separation efficiency of charge carriers in the heterostructured Bi/BiOBr/AgBr. The photocatalytic activity of Bi/BiOBr/AgBr microspheres just exhibited a slight decrease after three consecutive cycles. The photocatalytic mechanism investigation confirmed that the superoxide radicals (O2•-) were the dominant reactive oxygen species for RhB degradation in Bi/BiOBr/AgBr suspension.

Photocatalytic activity of Bi_2WO_6/Bi_2S_3 heterojunctions: the facilitation of exposed facets of Bi_2WO_6 substrate

International Nuclear Information System (INIS)

Yan, Long; Wang, Yufei; Shen, Huidong; Zhang, Yu; Li, Jian; Wang, Danjun

2017-01-01

Highlights: • Bi_2S_3/Bi_2WO_6 hybrids with exposed (020) Bi_2WO_6 facets have been synthesized. • X-ray photoelectron spectroscopy reveals that a small amount of Bi_2S_3 was formed. • The enhanced photoactivity of hybrids is due to heterojunction and (020) facets. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi_2S_3/Bi_2WO_6 hybrid architectures with exposed (020) Bi_2WO_6 facets have been synthesized via a controlled anion exchange approach. X-ray photoelectron spectroscopy (XPS) reveals that a small amount of Bi_2S_3 was formed on the surface of Bi_2WO_6 during the anion exchange process, thus leading to the transformation from the Bi_2WO_6 to Bi_2S_3/Bi_2WO_6. A rhodamine B (RhB) aqueous solution was chosen as model organic pollutants to evaluate the photocatalytic activities of the Bi_2S_3/Bi_2WO_6 catalysts. Under visible light irradiation, the Bi_2S_3/Bi_2WO_6-TAA displayed the excellent visible light photoactivities compared with pure Bi_2S_3, Bi_2WO_6 and other composite photocatalysts. The efficient photocatalytic activity of the Bi_2S_3/Bi_2WO_6-TAA composite microspheres was ascribed to the constructed heterojunctions and the inner electric field caused by the exposed (020) Bi_2WO_6 facets. Active species trapping experiments revealed that h"+ and O_2·"− are the main active species in the photocatalytic process. Furthermore, the as-obtained photocatalysts showed good photocatalytic activity after four recycles. The results presented in this study provide a new concept for the rational design and development of highly efficient photocatalysts.

Structural design of an in-line bolted joint for the space shuttle solid rocket motor case segments

Science.gov (United States)

Dorsey, John T.; Stein, Peter A.; Bush, Harold G.

1987-01-01

Results of a structural design study of an in-line bolted joint concept which can be used to assemble Space Shuttle Solid Rocket Motor (SRM) case segments are presented. Numerous parametric studies are performed to characterize the in-line bolted joint behavior as major design variables are altered, with the primary objective always being to keep the inside of the joint (where the O-rings are located) closed during the SRM firing. The resulting design has 180 1-inch studs, an eccentricity of -0.5 inch, a flange thickness of 3/4 inch, a bearing plate thickness of 1/4 inch, and the studs are subjected to a preload which is 70% of ultimate. The mass penalty per case segment joint for the in-line design is 346 lbm more than the weight penalty for the proposed capture tang fix.

Heterojunction BiOI/Bi2MoO6 nanocomposite with much enhanced photocatalytic activity

International Nuclear Information System (INIS)

Li, Wen Ting; Zheng, Yi Fan; Yin, Hao Yong; Song, Xu Chun

2015-01-01

BiOI/Bi 2 MoO 6 heterostructures with different amounts of BiOI were successfully prepared via a facile deposition method. The obtained BiOI/Bi 2 MoO 6 photocatalysts exhibited much higher visible light (λ > 420 nm) induced photocatalytic activity compared with single Bi 2 MoO 6 and BiOI photocatalysts. 20 % BiOI/Bi 2 MoO 6 nanocomposite exhibited the highest photocatalytic activity with almost all RhB decomposed within 70 min. However, excess BiOI covering on the surface of Bi 2 MoO 6 can inversely reduce the photocatalytic activity. The enhanced photocatalytic activities could be resulted from the function of the novel p–n heterojunction interface between Bi 2 MoO 6 and BiOI, which could separate photoinduced carriers efficiently. Possible mechanisms on the basis of the relative band positions were also discussed

Multiferroic BiFeO3-BiMnO3 Nanocheckerboard From First Principles

OpenAIRE

Palova, L.; Chandra, P.; Rabe, K. M.

2010-01-01

We present a first principles study of an unusual heterostructure, an atomic-scale checkerboard of BiFeO3-BiMnO3, and compare its properties to the two bulk constituent materials, BiFeO3 and BiMnO3. The "nanocheckerboard" is found to have a multiferroic ground state with the desired properties of each constituent: polar and ferrimagnetic due to BiFeO3 and BiMnO3, respectively. The effect of B-site cation ordering on magnetic ordering in the BiFeO3-BiMnO3 system is studied. The checkerboard ge...

Automatic segmentation of blood vessels from retinal fundus images ...

Indian Academy of Sciences (India)

The retinal blood vessels were segmented through color space conversion and color channel .... Retinal blood vessel segmentation was also attempted through multi-scale operators. A few works in this ... fundus camera at 35 degrees field of view. The image ... vessel segmentation is available from two human observers.

Edge preserving smoothing and segmentation of 4-D images via transversely isotropic scale-space processing and fingerprint analysis

International Nuclear Information System (INIS)

Reutter, Bryan W.; Algazi, V. Ralph; Gullberg, Grant T; Huesman, Ronald H.

2004-01-01

Enhancements are described for an approach that unifies edge preserving smoothing with segmentation of time sequences of volumetric images, based on differential edge detection at multiple spatial and temporal scales. Potential applications of these 4-D methods include segmentation of respiratory gated positron emission tomography (PET) transmission images to improve accuracy of attenuation correction for imaging heart and lung lesions, and segmentation of dynamic cardiac single photon emission computed tomography (SPECT) images to facilitate unbiased estimation of time-activity curves and kinetic parameters for left ventricular volumes of interest. Improved segmentation of lung surfaces in simulated respiratory gated cardiac PET transmission images is achieved with a 4-D edge detection operator composed of edge preserving 1-D operators applied in various spatial and temporal directions. Smoothing along the axis of a 1-D operator is driven by structure separation seen in the scale-space fingerprint, rather than by image contrast. Spurious noise structures are reduced with use of small-scale isotropic smoothing in directions transverse to the 1-D operator axis. Analytic expressions are obtained for directional derivatives of the smoothed, edge preserved image, and the expressions are used to compose a 4-D operator that detects edges as zero-crossings in the second derivative in the direction of the image intensity gradient. Additional improvement in segmentation is anticipated with use of multiscale transversely isotropic smoothing and a novel interpolation method that improves the behavior of the directional derivatives. The interpolation method is demonstrated on a simulated 1-D edge and incorporation of the method into the 4-D algorithm is described

In-situ synthesis of nanofibers with various ratios of BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} for effective trichloroethylene photocatalytic degradation

Energy Technology Data Exchange (ETDEWEB)

Zhang, Yifan [Department of Chemistry, Inha University, 100 Inharo, Incheon 402-751 (Korea, Republic of); Park, Mira [Department of Organic Materials and Fiber Engineering, Chonbuk National University, Jeonju 561-756 (Korea, Republic of); Kim, Hak Yong [Department of BIN Convergence Technology, Chonbuk National University, Jeonju, 561-756 (Korea, Republic of); Ding, Bin [College of Textiles, Donghua University, Shanghai 201620 (China); Park, Soo-Jin, E-mail: sjpark@inha.ac.kr [Department of Chemistry, Inha University, 100 Inharo, Incheon 402-751 (Korea, Republic of)

2016-10-30

Highlights: • BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN fibers were synthesized by in-situ method. • Photodegradation behavior of BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN fibers was measured under solar light irradiation. • BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4}/PAN fibers exhibited the highest photocatalytic activity. • Photocatalytic mechanism was discussed in detail. - Abstract: In this work, BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} (x + y + z = 1) composite nanofibers were prepared through electrospinning and the sol-gel methods. Photocatalytic degradation of trichloroethylene (TCE) by BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z}/PAN nanofibers was systematically investigated via gas chromatography (GC). Optimum photocatalytic activity was achieved with BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4} fibers under solar light irradiation. X-ray photoelectron spectroscopy (XPS) peaks due to C−O and C=O were observed at 286.0 and 288.3 eV, respectively, it indicated that the BiOCl{sub x}/BiOBr{sub y}/BiOI{sub z} mixture had been successfully doped on the polyacrylonitrile (PAN) fibers. Furthermore, X-ray diffraction (XRD) results also confirmed that we had synthesized the as-prepared composite nanofibers successfully. Photocatalytic activities of BiOCl{sub 0.3}/BiOBr{sub 0.3}/BiOI{sub 0.4} were up to 3 times higher than the pure BiOCl, BiOBr and BiOI samples, respectively.

Treatment of segmental tibial fractures with supercutaneous plating.

Science.gov (United States)

He, Xianfeng; Zhang, Jingwei; Li, Ming; Yu, Yihui; Zhu, Limei

2014-08-01

Segmental tibial fractures usually follow a high-energy trauma and are often associated with many complications. The purpose of this report is to describe the authors' results in the treatment of segmental tibial fractures with supercutaneous locking plates used as external fixators. Between January 2009 and March 2012, a total of 20 patients underwent external plating (supercutaneous plating) of the segmental tibial fractures using a less-invasive stabilization system locking plate (Synthes, Paoli, Pennsylvania). Six fractures were closed and 14 were open (6 grade IIIa, 2 grade IIIb, 4 grade II, and 2 grade I, according to the Gustilo classification). When imaging studies confirmed bone union, the plates and screws were removed in the outpatient clinic. Average time of follow-up was 23 months (range, 12-47 months). All fractures achieved union. Median time to union was 19 weeks (range, 12-40 weeks) for the proximal fractures and 22 weeks (range, 12-42 weeks) for the distal fractures. Functional results were excellent in 17 patients and good in 3. Delayed union of the fracture occurred in 2 patients. All patients' radiographs showed normal alignment. No rotational deformities and leg shortening were seen. No incidences of deep infection or implant failures occurred. Minor screw tract infection occurred in 2 patients. A new 1-stage protocol using supercutaneous plating as a definitive fixator for segmental tibial fractures is less invasive, has a lower cost, and has a shorter hospitalization time. Surgeons can achieve good reduction, soft tissue reconstruction, stable fixation, and high union rates using supercutaneous plating. The current patients obtained excellent knee and ankle joint motion and good functional outcomes and had a comfortable clinical course. Copyright 2014, SLACK Incorporated.

Facile Fabrication of BiOI/BiOCl Immobilized Films With Improved Visible Light Photocatalytic Performance

Directory of Open Access Journals (Sweden)

Yingxian Zhong

2018-03-01

Full Text Available HIGHLIGHTSA facial method was used to fabricate BiOI/BiOCl film at room temperature.30% BiOI/BiOCl showed an excellent photocatalytic activity and stability.Improvement of photocatalytic activity was owed to expanded visible light absorption and high separation efficiency of charge.Photocatalysis has been considered to be one of the most promising ways to photodegrade organic pollutants. Herein, a series of BiOI/BiOCl films coating on FTO were fabricated through a simple method at room temperature. The photocatalytic efficiency of 30%BiOI/BiOCl could reach more than 99% aiming to degrading RhB and MB after 90 and 120 min, respectively. Compared with BiOCl, 30%BiOI/BiOCl showed 12 times higher efficiency when degrading RhB. In comparison with BiOI, 30%BiOI/BiOCl showed 5 and 6 times higher efficiency when degrading RhB and MB, respectively. These obvious enhancements were attributed to expanded visible light absorption and high separation performance of photoinduced charge. Moreover, the photocatalytic activity of 30%BiOI/BiOCl had no obvious decrease after five recycles, suggesting that it was a promising photocatalyst for the removal of MB and RhB pollutants. Finally, the possible growth process for the BiOI/BiOCl thin films and photocatalysis mechanism were investigated in details. This work would provide insight to the reasonable construction of BiOX heterojunction and the photocatalytic mechanism in degrading organic pollutants.

Determining metal ion distributions using resonant scattering at very high-energy K-edges: Bi/Pb in Pb5Bi6Se14

International Nuclear Information System (INIS)

Zhang Yuegang; Lee, P.L.; Shastri, S.D.; Shu Deming; Wilkinson, A.P.; Chung Duck-Young; Kanatzidis, M.G.

2005-01-01

Powder diffraction data collected at ∝ 86 keV, and just below both the Pb and the Bi K-edges, on an imaging plate detector using synchrotron radiation from the Advanced Photon Source have been used to examine the Pb/Bi distribution over the 11 crystallographically distinct sites in Pb 5 Bi 6 Se 14 [space group P2 1 /m, a=16.0096(2) Aa, b=4.20148(4) Aa, c=21.5689(3) Aa and β=97.537(1) 0 ]. The scattering factors needed for the analyses were determined both by Kramers- Kronig transformation of absorption spectra and by analyses of diffraction patterns from reference compounds. Even with the relatively low scattering contrast that is available at the K-edges, it was possible to determine the Pb/Bi distribution and probe the presence of cation site vacancies in the material. The current results indicate that resonant scattering measurements at high-energy K-edges are a viable, and perhaps preferable, route to site occupancies when absorption from the sample or sample environment/container is a major barrier to the acquisition of high-quality resonant scattering data at lower-energy edges

Influence of photoinduced Bi-related self-doping on the photocatalytic activity of BiOBr nanosheets

Energy Technology Data Exchange (ETDEWEB)

Wu, Dan [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Yue, Songtao; Wang, Wei [College of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan 430074 (China); An, Tiacheng, E-mail: antc99@gig.ac.cn [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Li, Guiying [Institute of Environmental Health and Pollution Control, School of Environmental Science and Engineering, Guangdong University of Technology, Guangzhou 510006 (China); Ye, Liqun [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); College of Chemistry and Pharmaceutical Engineering, Nanyang Normal University, Nanyang 473061 (China); Yip, Ho Yin [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China); Wong, Po Keung, E-mail: pkwong@cuhk.edu.hk [School of Life Sciences, The Chinese University of Hong Kong, Shatin, NT, Hong Kong SAR (China)

2017-01-01

Highlights: • Bi{sup 5+} self-doped BiOBr nanosheets are achieved under UV irradiation. • Bi{sup 5+} is formed due to the oxidation of surface Bi{sup 3+} by photoexcited h{sup +} of BiOBr. • Two photoinduced h{sup +} mediated oxidation processes happen simultaneously. • Self-doped BiOBr is superior in phenol degradation and bacterial inactivation. • Bi{sup 5+} electron trapping induced photocatalytic enhancement mechanism is proposed. - Abstract: Under UV irradiation, self-doped Bi{sup 5+} is evidenced to be generated on the surface of BiOBr nanosheets, but with well-preserved crystal structure and morphology compared with pure counterpart. Bi{sup 5+} self-doping BiOBr (BiOBr-4) exhibits distinct photocatalytic mode for dyes degradation, as compared with pure BiOBr nanosheets. These photodegradation distinctions are mainly due to the simultaneous occurrence of two photoinduced hole (h{sup +}) mediated oxidation processes on the BiOBr surfaces: (1) a portion of photoexcited h{sup +} participates in the photocatalytic oxidation of dyes, and (2) partial h{sup +} involves the oxidation of Bi{sup 3+} to Bi{sup 5+}. Notably, BiOBr-4 nanosheets comparatively show superior photocatalytic activity for the phenol decomposition as well as the bacterial inactivation. Besides Bi{sup 5+} induced narrowed bandgap and enhanced light adsorption capacity, significantly, the oxidative Bi{sup 5+} acts as electron traps to promote the photoexcited electron-hole separation and accelerate h{sup +} migration, resulting in the considerable photocatalytic enhancement of BiOBr-4 nanosheets. These novel findings will not only give new insights into the photocatalytic mechanism but also explore new route to enhance photocatalytic performance of Bi-based materials.

Feature-space transformation improves supervised segmentation across scanners

DEFF Research Database (Denmark)

van Opbroek, Annegreet; Achterberg, Hakim C.; de Bruijne, Marleen

2015-01-01

Image-segmentation techniques based on supervised classification generally perform well on the condition that training and test samples have the same feature distribution. However, if training and test images are acquired with different scanners or scanning parameters, their feature distributions...

Bi3+–Pr3+ energy transfer processes and luminescent properties of LuAG:Bi,Pr and YAG:Bi,Pr single crystalline films

International Nuclear Information System (INIS)

Zorenko, Y.; Gorbenko, V.; Savchyn, V.; Zorenko, T.; Nikl, M.; Mares, J.A.; Beitlerova, A.; Jary, V.

2013-01-01

Absorption, cathodoluminescence, excitation spectra of photoluminescence (PL) and PL decay kinetics were studied at 300 K for the double doped with Bi 3+ –Pr 3+ and separately doped with Bi 3+ and Pr 3+ Lu 3 Al 5 O 12 (LuAG) and Y 3 Al 5 O 12 (YAG) single crystalline film (SCF) phosphors grown by the liquid phase epitaxy method. The emission bands in the UV range arising from the intrinsic radiative transitions of Bi 3+ based centers, and emission bands in the visible range, related to the luminescence of excitons localized around Bi 3+ based centers, were identified both in Bi–Pr and Bi-doped LuAG and YAG SCFs. The energy transfer processes from the host lattice simultaneously to Bi 3+ and Pr 3+ ions and from Bi 3+ to Pr 3+ ions were investigated. Competition between Pr 3+ and Bi 3+ ions in the energy transfer processes from the LuAG and YAG hosts was evidenced. The strong decrease of the intensity of Pr 3+ luminescence both in LuAG:Pr and YAG:Pr SCFs phosphors, grown from Bi 2 O 3 flux, is observed due to the quenching influence of Bi 3+ flux related impurity. Due to overlap of the UV emission band of Bi 3+ centers with the f–d absorption bands of Pr 3+ ions in the UV range and the luminescence of excitons localized around Bi ions with the f–f absorption bands of Pr 3+ ions in the visible range, an effective energy transfer from Bi 3+ ions to Pr 3+ ions takes place in LuAG:Bi,Pr and YAG:Bi,Pr SCFs, resulting in the appearance of slower component in the decay kinetics of the Pr 3+ d–f luminescence. -- Highlights: • Bi and Pr doped film phosphor grown by liquid phase epitaxy method. • Energy transfer from Bi 3+ to Pr 3+ ions. • Strong quenching of the Pr 3+ luminescence by Bi 3+ co-dopant

Facile Fabrication of BiOI/BiOCl Immobilized Films with Improved Visible Light Photocatalytic Performance

Science.gov (United States)

Zhong, Yingxian; Liu, Yuehua; Wu, Shuang; Zhu, Yi; Chen, Hongbin; Yu, Xiang; Zhang, Yuanming

2018-03-01

Photocatalysis has been considered to be one of the most promising ways to photodegrade organic pollutants. Herein, a series of BiOI/BiOCl films coating on FTO were fabricated through a simple method at room temperature. The photocatalytic efficiency of 30%BiOI/BiOCl could reach more than 99% aiming to degrading RhB and MB after 90 and 120 min, respectively. Compared with BiOCl, 30%BiOI/BiOCl showed 12 times higher efficiency when degrading RhB. In comparison with BiOI, 30%BiOI/BiOCl showed 5 and 6 times higher efficiency when degrading RhB and MB, respectively. These obvious enhancements were attributed to expanded visible light absorption and high separation performance of photoinduced charge. Moreover, the photocatalytic activity of 30%BiOI/BiOCl had no obvious decrease after 5 recycles, suggesting that it was a promising photocatalyst for the removal of MB and RhB pollutants. Finally, the possible growth process for the BiOI/BiOCl thin films and photocatalysis mechanism were investigated in details. This work would provide insight to the reasonable construction of BiOX heterojunction and the photocatalytic mechanism in degrading organic pollutants.

Radioisotope space power generator. Annual report, October 1978-September 1979

International Nuclear Information System (INIS)

Elsner, N.B.; Chin, J.; Staley, H.G.; Bass, J.C.; Morris, C.C.; Shearer, C.H.; Steeger, E.J.

1982-03-01

The emphasis of the Isotec Technology Program shifted from development of a Galileo generator to study of a segmented selenide element and couple technology. The goal of the FY 79 program was to determine the feasibility of fabricating segmented selenide P and N elements which exploit the high thermoelectric efficiency of (Cu,Ag) 2 Se and Gd 2 Se 3 materials. A preliminary evaluation of segmented element efficiencies, material compatibilities, and fabrication abilities was used to select (Cu,Ag) 2 Se/Fe(Bi,Sb) 2 Te 3 for the P element and Gd 2 Se 3 /PbTe for the N element. The iron barrier between the (Cu,Ag) 2 Se and (Bi,Sb) 2 Te 3 prevented degradation of thermoelectric properties from copper contamination of the (Bi,Sb) 2 Te 3 . Fabrication processes for both elements were developed. Gd 2 Se 3 was friable and difficult to fabricate crack-free. It also exhibited a phase transition from cubic to orthorhombic, which increased its susceptibility to microcracking and reduced its thermoelectric efficiency. Life testing of an all-bonded couple with unsegmented (Cu,Ag) 2 Se P-type and Gd 2 Se 3 N-type elements was stopped after 3300 h in a nominal 830 0 C/390 0 C thermal gradient. The Gd 2 Se 3 leg did not show any significant degradation during the test. Examination of the hot end of the P element showed the need for a less reactive hot cap material and an improved vapor supression system. Module testing of a 1-W (Bi,Sb) 2 (Se,Te) 3 generator was performed for 5000 h with no degradation in power. High-temperature Thermid 600 adhesive curing cycles were examined, 75-mW module loading tests were performed, and diagnostic examination of RTG-2A and RTG-201 was completed

On the electronic structure and thermoelectric properties of BiTeBr and BiTeI single crystals and of BiTeI with the addition of BiI3 and CuI

International Nuclear Information System (INIS)

Kulbachinskii, Vladimir A.; Kytin, Vladimir G.; Kudryashov, Alexey A.; Kuznetsov, Alexei N.; Shevelkov, Andrei V.

2012-01-01

The electronic structures were calculated for BiTeBr and BiTeI using the density-functional theory approach and accounting for the strong spin–orbital interaction. Qualitatively, the band structures for two compounds are similar, showing strong mixing of the p states of all elements in vicinity of the Fermi level, with the band gaps of 0.595 and 0.478 eV for BiTeBr and BiTeI, respectively. The optimized crystal structures show a tendency for the Bi–X (X=Br, I) bond elongation compared to the Bi–Te one. Both compounds are intrinsic n-type semiconductors but display a metallic-like conductivity coupled to rather large thermopower, which is rationalized within the frames of the acoustic phonons scattering model. Because of larger thermopower BiTeBr exhibits a twice higher thermoelectric figure-of-merit near room temperature, ZT=0.17, compared to BiTeI. The addition of 1 mass% of BiI 3 or CuI to BiTeI decreases the mobility of electrons by two orders of magnitude, leading to significantly lower electrical conductivity, but at the same time effectively reduces the thermal conductivity. The prospects of further enhancing the thermoelectric efficiency are briefly discussed. - Graphical abstract: View of the crystal structure of BiTeBr is shown in the figure The optimized crystal structures show a tendency for the Bi–X (X=Br, I) bond elongation compared to the Bi–Te one. The electronic structures were calculated for BiTeBr and BiTeI using the density-functional theory approach and accounting for the strong spin–orbital interaction. Qualitatively, the band structures for two compounds are similar, showing strong mixing of the p states of all elements in vicinity of the Fermi level, with the band gaps of 0.595 and 0.478 eV for BiTeBr and BiTeI, respectively. Both compounds are intrinsic n-type semiconductors but display a metallic-like conductivity coupled to rather large thermopower, which is rationalized within the frames of the acoustic phonons scattering

Monitoring fish distributions along electrofishing segments

Science.gov (United States)

Miranda, Leandro E.

2014-01-01

Electrofishing is widely used to monitor fish species composition and relative abundance in streams and lakes. According to standard protocols, multiple segments are selected in a body of water to monitor population relative abundance as the ratio of total catch to total sampling effort. The standard protocol provides an assessment of fish distribution at a macrohabitat scale among segments, but not within segments. An ancillary protocol was developed for assessing fish distribution at a finer scale within electrofishing segments. The ancillary protocol was used to estimate spacing, dispersion, and association of two species along shore segments in two local reservoirs. The added information provided by the ancillary protocol may be useful for assessing fish distribution relative to fish of the same species, to fish of different species, and to environmental or habitat characteristics.

Generation of calves persistently infected with HoBi-like pestivirus and comparison of methods for detection of these persistent infections.

Science.gov (United States)

Bauermann, F V; Falkenberg, S M; Vander Ley, B; Decaro, N; Brodersen, B W; Harmon, A; Hessman, B; Flores, E F; Ridpath, J F

2014-11-01

The identification and elimination of persistently infected (PI) cattle are the most effective measures for controlling bovine pestiviruses, including bovine viral diarrhea virus (BVDV) and the emerging HoBi-like viruses. Here, colostrum-deprived calves persistently infected with HoBi-like pestivirus (HoBi-like PI calves) were generated and sampled (serum, buffy coat, and ear notches) on the day of birth (DOB) and weekly for 5 consecutive weeks. The samples were subjected to diagnostic tests for BVDV--two reverse transcriptase PCR (RT-PCR) assays, two commercial real-time RT quantitative PCR (RT-qPCR), two antigen capture enzyme-linked immunosorbent assays (ACE), and immunohistochemistry (IHC)--and to HoBi-like virus-specific RT-PCR and RT-qPCR assays. The rate of false negatives varied among the calves. The HoBi-like virus-specific RT-PCR detected HoBi-like virus in 83%, 75%, and 87% of the serum, buffy coat, and ear notch samples, respectively, while the HoBi-like RT-qPCR detected the virus in 83%, 96%, and 62%, respectively. In comparison, the BVDV RT-PCR test had a higher rate of false negatives in all tissue types, especially for the ear notch samples (missing detection in at least 68% of the samples). The commercial BVDV RT-qPCRs and IHC detected 100% of the ear notch samples as positive. While ACE based on the BVDV glycoprotein E(rns) detected infection in at least 87% of ear notches, no infections were detected using NS3-based ACE. The BVDV RT-qPCR, ACE, and IHC yielded higher levels of detection than the HoBi-like virus-specific assays, although the lack of differentiation between BVDV and HoBi-like viruses would make these tests of limited use for the control and/or surveillance of persistent HoBi-like virus infection. An improvement in HoBi-like virus tests is required before a reliable HoBi-like PI surveillance program can be designed. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

Medical image segmentation using genetic algorithms.

Science.gov (United States)

Maulik, Ujjwal

2009-03-01

Genetic algorithms (GAs) have been found to be effective in the domain of medical image segmentation, since the problem can often be mapped to one of search in a complex and multimodal landscape. The challenges in medical image segmentation arise due to poor image contrast and artifacts that result in missing or diffuse organ/tissue boundaries. The resulting search space is therefore often noisy with a multitude of local optima. Not only does the genetic algorithmic framework prove to be effective in coming out of local optima, it also brings considerable flexibility into the segmentation procedure. In this paper, an attempt has been made to review the major applications of GAs to the domain of medical image segmentation.

Data Transformation Functions for Expanded Search Spaces in Geographic Sample Supervised Segment Generation

Directory of Open Access Journals (Sweden)

Christoff Fourie

2014-04-01

Full Text Available Sample supervised image analysis, in particular sample supervised segment generation, shows promise as a methodological avenue applicable within Geographic Object-Based Image Analysis (GEOBIA. Segmentation is acknowledged as a constituent component within typically expansive image analysis processes. A general extension to the basic formulation of an empirical discrepancy measure directed segmentation algorithm parameter tuning approach is proposed. An expanded search landscape is defined, consisting not only of the segmentation algorithm parameters, but also of low-level, parameterized image processing functions. Such higher dimensional search landscapes potentially allow for achieving better segmentation accuracies. The proposed method is tested with a range of low-level image transformation functions and two segmentation algorithms. The general effectiveness of such an approach is demonstrated compared to a variant only optimising segmentation algorithm parameters. Further, it is shown that the resultant search landscapes obtained from combining mid- and low-level image processing parameter domains, in our problem contexts, are sufficiently complex to warrant the use of population based stochastic search methods. Interdependencies of these two parameter domains are also demonstrated, necessitating simultaneous optimization.

Hierarchical pre-segmentation without prior knowledge

NARCIS (Netherlands)

Kuijper, A.; Florack, L.M.J.

2001-01-01

A new method to pre-segment images by means of a hierarchical description is proposed. This description is obtained from an investigation of the deep structure of a scale space image – the input image and the Gaussian filtered ones simultaneously. We concentrate on scale space critical points –

Corrosion behavior of as-cast binary Mg-Bi alloys in Hank's solution

Directory of Open Access Journals (Sweden)

Wei-li Cheng

2015-11-01

Full Text Available Biodegradable Mg-xBi (x = 3, 6 and 9wt.% alloys were fabricated by ingot casting, and the change of corrosion behavior of the alloys in the Hank's solution was analyzed with respect to the microstructure using optical micrograph (OM, X-ray diffraction (XRD, scanning electron microscope (SEM equipped with an energy dispersive X-ray spectrometer (EDS, electrochemical and immersion tests. The results show that the microstructures of the as-cast Mg-Bi alloys mainly consisted of dendritic ?Mg grains and Mg3Bi2 phase in common, with the secondary dendrite arm spacing (SDAS decreasing significantly from 41.2 靘 to 25.4 靘 and the fraction of Mg3Bi2 increasing from 3.1% to 10.7%. Furthermore, the corrosion rate increasing from 1.32 mm昦-1 to 8.07 mm昦-1 as the Bi content was increased from 3wt.% to 9wt.%. The reduced corrosion resistance was mainly ascribed to the increasing fraction of the second phase particles, which bring positive effects on the development of pitting.

Synthesis and Dielectric Properties of Ba3NaBiNb10O30 Ceramics

Institute of Scientific and Technical Information of China (English)

无

2003-01-01

A new niobate Ba3NaBiNb10O30 was synthesized by the solid state reaction.The reaction mixture was characterized by thermogravimetric and differential thermal analysis (TG-DTA),X-ray diffraction and dielectric constant measurements.The results show that Ba3NaBiNb10O30 has an orthorhombic tungsten bronze structure with space group Cmm2 and the unit cell parameters are a=1.7660(1) nm,a=1.7626(1) nm,c=0.78621(6) nm,Z=4.Ba3NaBiNb10O30 undergoes two phase transitions at 200℃ and 400℃,respectively.

Preparation, characterization and enhanced visible-light photocatalytic activities of BiPO4/BiVO4 composites

International Nuclear Information System (INIS)

Wu, Siyuan; Zheng, Hong; Lian, Youwei; Wu, Yiying

2013-01-01

Graphical abstract: - Highlights: • BiPO 4 /BiVO 4 composites were successfully prepared by the hydrothermal method. • BiPO 4 /BiVO 4 composites exhibited broad absorption in the visible region. • Visible-light photocatalytic activities of BiPO 4 /BiVO 4 composites were enhanced. • P/V molar ratio and pH value of the reaction affect photocatalytic activity. • The mechanism of enhanced visible-light photocatalytic activities was discussed. - Abstract: BiPO 4 /BiVO 4 composites with different P/V molar ratios were prepared by the hydrothermal method and the effect of pH values of hydrothermal reaction on photocatalytic activity of BiPO 4 /BiVO 4 composite was investigated. The photocatalysts were characterized by X-ray diffraction, field emission scanning electron microscopy, energy-dispersive spectroscopy, X-ray photoelectron spectroscopy and UV–vis diffuse reflectance spectroscopy. The photocatalytic property of BiPO 4 /BiVO 4 was evaluated by photocatalytic degradation of Methylene blue under visible light irradiation. The results showed that the photocatalytic activity of the composites was much higher than that of pure BiPO 4 and BiVO 4 . The rate constant of Methylene blue degradation over BiPO 4 /BiVO 4 (P/V molar ratio of 5:1 and hydrothermal reaction pH value of 1.5) is 1.7 times that of pure BiVO 4 . The photocatalytic activity enhancement of BiPO 4 /BiVO 4 composite is closely related to the BiVO 4 functioning as a sensitizer to adsorb visible light and the heterojunction of BiPO 4 /BiVO 4 acting as an active center for hindering the rapid recombination of electron–hole pairs during the photocatalytic reaction

Spatial profile of thermoelectric effects during Peltier pulsing in Bi and Bi/MnBi eutectic

Science.gov (United States)

Silberstein, R. P.; Larson, D. J., Jr.

1987-01-01

The spatial profile of the thermal transients that occur during and following the current pulsing associated with Peltier Interface Demarcation during directional solidification is studied. Results for pure Bi are presented in detail and compared with corresponding results for the Bi/MnBi eutectic. Significant thermal transients occur throughout the sample that can be accounted for by the Peltier effect, the Thomson effect, and Joule heating. These effects are separated and their behavior is studied as a function of time, current density, and position with respect to the solid/liquid interface.

Seismicity of Romania: fractal properties of earthquake space, time and energy distributions and their correlation with segmentation of subducted lithosphere and Vrancea seismic source

International Nuclear Information System (INIS)

Popescu, E.; Ardeleanu, L.; Bazacliu, O.; Popa, M.; Radulian, M.; Rizescu, M.

2002-01-01

For any strategy of seismic hazard assessment, it is important to set a realistic seismic input such as: delimitation of seismogenic zones, geometry of seismic sources, seismicity regime, focal mechanism and stress field. The aim of the present project is a systematic investigation focused on the problem of Vrancea seismic regime at different time, space and energy scales which can offer a crucial information on the seismogenic process of this peculiar seismic area. The departures from linearity of the time, space and energy distributions are associated with inhomogeneities in the subducting slab, rheology, tectonic stress distribution and focal mechanism. The significant variations are correlated with the existence of active and inactive segments along the seismogenic zone, the deviation from linearity of the frequency-magnitude distribution is associated with the existence of different earthquake generation models and the nonlinearities showed in the time series are related with the occurrence of the major earthquakes. Another important purpose of the project is to analyze the main crustal seismic sequences generated on the Romanian territory in the following regions: Ramnicu Sarat, Fagaras-Campulung, Banat. Time, space and energy distributions together with the source parameters and scaling relations are investigated. The analysis of the seismicity and clustering properties of the earthquakes generated in both Vrancea intermediate-depth region and Romanian crustal seismogenic zones, achieved within this project, constitutes the starting point for the study of seismic zoning, seismic hazard and earthquake prediction. The data set consists of Vrancea subcrustal earthquake catalogue (since 1974 and continuously updated) and catalogues with events located in the other crustal seimogenic zones of Romania. To build up these data sets, high-quality information made available through multiple international cooperation programs is considered. The results obtained up to

The BiCu{sub 1−x}OS oxysulfide: Copper deficiency and electronic properties

Energy Technology Data Exchange (ETDEWEB)

Berthebaud, D.; Guilmeau, E.; Lebedev, O.I. [Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 6 bd du Maréchal Juin, F-14050 CAEN Cedex 4 (France); Maignan, A., E-mail: antoine.maignan@ensicaen.fr [Laboratoire CRISMAT, UMR 6508 CNRS/ENSICAEN/UCBN, 6 bd du Maréchal Juin, F-14050 CAEN Cedex 4 (France); Gamon, J.; Barboux, P. [Institut de Recherche de Chimie de Paris, Ecole Nationale Supérieure de Chimie de Paris, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 09 France (France)

2016-05-15

An oxysulfide series of nominal compositions BiCu{sub 1−x}OS with x<0.20 has been prepared and its structural properties characterized by combining powder X-ray diffraction and transmission electron microscopy techniques. It is found that this oxysulfide, crystallizing in the P4/nmm space group, tends to adopt a constant amount of copper vacancy corresponding to x=0.05 in the BiCu{sub 1−x}OS formula. The presence of Cu vacancies is confirmed by HAADF-STEM analysis showing, in the Cu atomic columns, alternating peaks of different intensities in some very localized regions. For larger Cu deficiencies (x>0.05 in the nominal composition), other types of structural nanodefects are evidenced such as bismuth oxysulfides of the “BiOS” ternary system which might explain the report of superconductivity for the BiCu{sub 1−x}OS oxysulfide. Local epitaxial growth of the BiCuOS oxysulfide on top of CuO is also observed. In marked contrast to the BiCu{sub 1−x}OSe oxyselenide, these results give an explanation to the limited impact of Cu deficiency on the Seebeck coefficient in BiCu{sub 1−x}OS compounds. - Graphical abstract: High resolution TEM image showing a Bi(Cu)OS/Bi{sub 2}O{sub 2}S interface and corresponding dislocation region. The Bi(Cu)OS structure adopts a rather constant Cu content (near 0.95); starting from BiCuOS leads to the formation of defects such as the Bi{sub 2}O{sub 2}S oxysulfide.

Synthesis, structure, and characterization of two new bismuth(III) selenite/tellurite nitrates: [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3)

Science.gov (United States)

Meng, Chang-Yu; Wei, Ming-Fang; Geng, Lei; Hu, Pei-Qing; Yu, Meng-Xia; Cheng, Wen-Dan

2016-07-01

Two new bismuth(III) selenite/tellurite nitrates, [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3), have been synthesized by conventional facile hydrothermal method at middle temperature 200 °C and characterized by single-crystal X-ray diffraction, powder diffraction, UV-vis-NIR optical absorption spectrum, infrared spectrum and thermal analylsis. Both [(Bi3O2)(SeO3)2](NO3) and [Bi(TeO3)](NO3) crystallize in the monoclinic centronsymmetric space group P21/c with a=9.9403(4) Å, b=9.6857(4) Å, c=10.6864(5) Å, β=93.1150(10)° for [(Bi3O2)(SeO3)2](NO3) and a=8.1489(3) Å, b=9.0663(4) Å, c=7.4729(3) Å, β=114.899(2)° for Bi(TeO3)(NO3), respectively. The two compounds, whose structures are composed of three different asymmetric building units, exhibit two different types of structures. The structure of [(Bi3O2)(SeO3)2](NO3) features a three-dimensional (3D) bismuth(III) selenite cationic tunnel structure [(Bi3O2)(SeO3)2] 3∞ with NO3- anion group filling in the 1D tunnel along b axis. The structure of [Bi(TeO3)](NO3) features 2D bismuth(III) tellurite [Bi(TeO3)2]2∞ layers separated by NO3- anion groups. The results of optical diffuse-reflectance spectrum measurements and electronic structure calculations based on density functional theory methods show that the two compounds are wide band-gap semiconductors.

Segmentation of color images by chromaticity features using self-organizing maps

Directory of Open Access Journals (Sweden)

Farid García-Lamont

2016-05-01

Full Text Available Usually, the segmentation of color images is performed using cluster-based methods and the RGB space to represent the colors. The drawback with these methods is the a priori knowledge of the number of groups, or colors, in the image; besides, the RGB space issensitive to the intensity of the colors. Humans can identify different sections within a scene by the chromaticity of its colors of, as this is the feature humans employ to tell them apart. In this paper, we propose to emulate the human perception of color by training a self-organizing map (SOM with samples of chromaticity of different colors. The image to process is mapped to the HSV space because in this space the chromaticity is decoupled from the intensity, while in the RGB space this is not possible. Our proposal does not require knowing a priori the number of colors within a scene, and non-uniform illumination does not significantly affect the image segmentation. We present experimental results using some images from the Berkeley segmentation database by employing SOMs with different sizes, which are segmented successfully using only chromaticity features.

State diagram of Pr-Bi system

International Nuclear Information System (INIS)

Abulkhaev, V.L.; Ganiev, I.N.

1994-01-01

By means of thermal differential analysis, X-ray and microstructural analysis the state diagram of Pr-Bi system was studied. Following intermetallic compounds were defined in the system: Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 , Pr Bi, PrBi 2 , Pr 2 Bi, Pr 5 Bi 3 , Pr 4 Bi 3 and PrBi 2 . The data analysis on Ln-Bi diagram allowed to determine the regularity of change of properties of intermetallic compounds in the line of rare earth elements of cerium subgroup.

Medical Image Segmentation using the HSI color space and Fuzzy Mathematical Morphology

Science.gov (United States)

Gasparri, J. P.; Bouchet, A.; Abras, G.; Ballarin, V.; Pastore, J. I.

2011-12-01

Diabetic retinopathy is the most common cause of blindness among the active population in developed countries. An early ophthalmologic examination followed by proper treatment can prevent blindness. The purpose of this work is develop an automated method for segmentation the vasculature in retinal images in order to assist the expert in the evolution of a specific treatment or in the diagnosis of a potential pathology. Since the HSI space has the ability to separate the intensity of the intrinsic color information, its use is recommended for the digital processing images when they are affected by lighting changes, characteristic of the images under study. By the application of color filters, is achieved artificially change the tone of blood vessels, to better distinguish them from the bottom. This technique, combined with the application of fuzzy mathematical morphology tools as the Top-Hat transformation, creates images of the retina, where vascular branches are markedly enhanced over the original. These images provide the visualization of blood vessels by the specialist.

Medical Image Segmentation using the HSI color space and Fuzzy Mathematical Morphology

International Nuclear Information System (INIS)

Gasparri, J P; Bouchet, A; Abras, G; Ballarin, V; Pastore, J I

2011-01-01

Diabetic retinopathy is the most common cause of blindness among the active population in developed countries. An early ophthalmologic examination followed by proper treatment can prevent blindness. The purpose of this work is develop an automated method for segmentation the vasculature in retinal images in order to assist the expert in the evolution of a specific treatment or in the diagnosis of a potential pathology. Since the HSI space has the ability to separate the intensity of the intrinsic color information, its use is recommended for the digital processing images when they are affected by lighting changes, characteristic of the images under study. By the application of color filters, is achieved artificially change the tone of blood vessels, to better distinguish them from the bottom. This technique, combined with the application of fuzzy mathematical morphology tools as the Top-Hat transformation, creates images of the retina, where vascular branches are markedly enhanced over the original. These images provide the visualization of blood vessels by the specialist.

Optimal graph based segmentation using flow lines with application to airway wall segmentation

DEFF Research Database (Denmark)

Petersen, Jens; Nielsen, Mads; Lo, Pechin Chien Pau

2011-01-01

This paper introduces a novel optimal graph construction method that is applicable to multi-dimensional, multi-surface segmentation problems. Such problems are often solved by refining an initial coarse surface within the space given by graph columns. Conventional columns are not well suited...

Segmentation of liver tumors on CT images

International Nuclear Information System (INIS)

Pescia, D.

2011-01-01

This thesis is dedicated to 3D segmentation of liver tumors in CT images. This is a task of great clinical interest since it allows physicians benefiting from reproducible and reliable methods for segmenting such lesions. Accurate segmentation would indeed help them during the evaluation of the lesions, the choice of treatment and treatment planning. Such a complex segmentation task should cope with three main scientific challenges: (i) the highly variable shape of the structures being sought, (ii) their similarity of appearance compared with their surrounding medium and finally (iii) the low signal to noise ratio being observed in these images. This problem is addressed in a clinical context through a two step approach, consisting of the segmentation of the entire liver envelope, before segmenting the tumors which are present within the envelope. We begin by proposing an atlas-based approach for computing pathological liver envelopes. Initially images are pre-processed to compute the envelopes that wrap around binary masks in an attempt to obtain liver envelopes from estimated segmentation of healthy liver parenchyma. A new statistical atlas is then introduced and used to segmentation through its diffeomorphic registration to the new image. This segmentation is achieved through the combination of image matching costs as well as spatial and appearance prior using a multi-scale approach with MRF. The second step of our approach is dedicated to lesions segmentation contained within the envelopes using a combination of machine learning techniques and graph based methods. First, an appropriate feature space is considered that involves texture descriptors being determined through filtering using various scales and orientations. Then, state of the art machine learning techniques are used to determine the most relevant features, as well as the hyper plane that separates the feature space of tumoral voxels to the ones corresponding to healthy tissues. Segmentation is then

One-step growth of nanosheet-assembled BiOCl/BiOBr microspheres for highly efficient visible photocatalytic performance

Science.gov (United States)

Zhang, Jinfeng; Lv, Jiali; Dai, Kai; Liang, Changhao; Liu, Qi

2018-02-01

In this work, we have developed a simple synthetic approach of nanosheet-assembled BiOCl/BiOBr microspheres by an ethylene glycol (EG)-assisted hydrothermal method. The crystalline form, morphology, chemical composition, optical performance and surface area of BiOCl/BiOBr microspheres were identified using X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution TEM (HRTEM), scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy spectra (EDX), UV-vis diffuse reflectance spectroscopy (DRS) analysis, high resolution X-ray photoelectron spectra (XPS) and N2 adsorption-desorption isotherms. BiOCl/BiOBr microspheres were nanosheet-assembled particles, which possessed visible light absorption under LED light irridation. Additionally, the methylene blue (MB) photodegradation performance of different BiOCl/BiOBr microspheres irradiated under 410 nm LED light arrays were investigated, the results exhibited that as-prepared BiOCl/BiOBr products showed higher catalytic effiency than pure BiOCl or BiOBr. By optimizing the composition ration of the BiOCl and BiOBr, up to 93% degradation rate can be obtained in the 40%BiOCl/BiOBr microspheres. Finally, the photocatalytic mechanism of BiOCl/BiOBr microspheres had been proposed.

Structural defects in multiferroic BiMnO3 studied by transmission electron microscopy and electron energy-loss spectroscopy

International Nuclear Information System (INIS)

Yang, H.; Chi, Z. H.; Yao, L. D.; Zhang, W.; Li, F. Y.; Jin, C. Q.; Yu, R. C.

2006-01-01

The multiferroic material BiMnO 3 synthesized under high pressure has been systematically studied by transmission electron microscopy and electron energy-loss spectroscopy, and some important structural defects are revealed in this multiferroic material. The frequently observed defects are characterized to be Σ3(111) twin boundaries, Ruddlesden-Popper [Acta Crystallogr. 11, 54 (1958)] antiphase boundaries, and a p p superdislocations connected with a small segment of Ruddlesden-Popper defect. These defects are present initially in the as-synthesized sample. In addition, we find that ordered voids (oxygen vacancies) are easily introduced into the multiferroic BiMnO 3 by electron-beam irradiation

Evaluation and development of a novel binocular treatment (I-BiT™) system using video clips and interactive games to improve vision in children with amblyopia ('lazy eye'): study protocol for a randomised controlled trial.

Science.gov (United States)

Foss, Alexander J; Gregson, Richard M; MacKeith, Daisy; Herbison, Nicola; Ash, Isabel M; Cobb, Sue V; Eastgate, Richard M; Hepburn, Trish; Vivian, Anthony; Moore, Diane; Haworth, Stephen M

2013-05-20

Amblyopia (lazy eye) affects the vision of approximately 2% of all children. Traditional treatment consists of wearing a patch over their 'good' eye for a number of hours daily, over several months. This treatment is unpopular and compliance is often low. Therefore results can be poor. A novel binocular treatment which uses 3D technology to present specially developed computer games and video footage (I-BiT™) has been studied in a small group of patients and has shown positive results over a short period of time. The system is therefore now being examined in a randomised clinical trial. Seventy-five patients aged between 4 and 8 years with a diagnosis of amblyopia will be randomised to one of three treatments with a ratio of 1:1:1 - I-BiT™ game, non-I-BiT™ game, and I-BiT™ DVD. They will be treated for 30 minutes once weekly for 6 weeks. Their visual acuity will be assessed independently at baseline, mid-treatment (week 3), at the end of treatment (week 6) and 4 weeks after completing treatment (week 10). The primary endpoint will be the change in visual acuity from baseline to the end of treatment. Secondary endpoints will be additional visual acuity measures, patient acceptability, compliance and the incidence of adverse events. This is the first randomised controlled trial using the I-BiT™ system. The results will determine if the I-BiT™ system is effective in the treatment of amblyopia and will also determine the optimal treatment for future development. ClinicalTrials.gov identifier: NCT01702727.

Shape-tailored local descriptors and their application to segmentation and tracking

KAUST Repository

Khan, Naeemullah; Algarni, Marei Saeed Mohammed; Yezzi, Anthony; Sundaramoorthi, Ganesh

2015-01-01

We propose new dense descriptors for texture segmentation. Given a region of arbitrary shape in an image, these descriptors are formed from shape-dependent scale spaces of oriented gradients. These scale spaces are defined by Poisson-like partial differential equations. A key property of our new descriptors is that they do not aggregate image data across the boundary of the region, in contrast to existing descriptors based on aggregation of oriented gradients. As an example, we show how the descriptor can be incorporated in a Mumford-Shah energy for texture segmentation. We test our method on several challenging datasets for texture segmentation and textured object tracking. Experiments indicate that our descriptors lead to more accurate segmentation than non-shape dependent descriptors and the state-of-the-art in texture segmentation.

Shape-tailored local descriptors and their application to segmentation and tracking

KAUST Repository

Khan, Naeemullah

2015-06-07

We propose new dense descriptors for texture segmentation. Given a region of arbitrary shape in an image, these descriptors are formed from shape-dependent scale spaces of oriented gradients. These scale spaces are defined by Poisson-like partial differential equations. A key property of our new descriptors is that they do not aggregate image data across the boundary of the region, in contrast to existing descriptors based on aggregation of oriented gradients. As an example, we show how the descriptor can be incorporated in a Mumford-Shah energy for texture segmentation. We test our method on several challenging datasets for texture segmentation and textured object tracking. Experiments indicate that our descriptors lead to more accurate segmentation than non-shape dependent descriptors and the state-of-the-art in texture segmentation.

Optical gain in GaAsBi-based quantum-well diode lasers (Conference Presentation)

Science.gov (United States)

Marko, Igor P.; Broderick, Christopher A.; Jin, Shirong; Ludewig, Peter; Stolz, Wolfgang; Volz, Kerstin; Rorison, Judy M.; O'Reilly, Eoin P.; Sweeney, Stephen J.

2017-02-01

GaAsBi offers the possibility to develop near-IR semiconductor lasers such that the spin-orbit-split-off energy (ΔSO) is greater than the bandgap (Eg) in the active region with lasing wavelengths in the datacom/telecom range of 1.3-1.6 μm. This promises to suppress the dominant efficiency-limiting loss processes as Auger recombination, involving the generation of "hot" holes in the spin-orbit split-off band (the so-called "CHSH" process), and inter-valence band absorption (IVBA), where emitted photons are re-absorbed in the active region, thereby increasing the internal optical losses and negatively impacting upon the laser characteristics being responsible for the main energy consumption. In addition to growth and fabrication processes refinement, a key aspect of efforts to continue the advancement of the GaAsBi material system for laser applications is to develop a quantitative understanding of the impact of Bi on key device parameters. In this work, we present the first experimental measurements of the absorption, spontaneous emission, and optical gain spectra of GaAsBi/AlGaAs QW lasers using a segmented contact method and a theoretical analysis of these devices, which shows good quantitative agreement with the experiment. Internal optical losses of 10-15 cm-1 and peak modal gain of 24 cm-1 are measured at threshold and a peak material gain is estimated to be 1500 cm-1 at current density of 2 kA/cm-2, which agrees well with the calculated value of 1560 cm-1. The theoretical calculations also enabled us to identify and quantify Bi composition variations across the wafer and Bi-induced inhomogeneous broadening of the optical spectra.

Optimal graph based segmentation using flow lines with application to airway wall segmentation

DEFF Research Database (Denmark)

Petersen, Jens; Nielsen, Mads; Lo, Pechin

2011-01-01

This paper introduces a novel optimal graph construction method that is applicable to multi-dimensional, multi-surface segmentation problems. Such problems are often solved by refining an initial coarse surface within the space given by graph columns. Conventional columns are not well suited for ...

Interpretative intra- and interobserver reproducibility of Stress/Rest 99m Tc-steamboat's myocardial perfusion SPECT using semi quantitative 20-segment model

International Nuclear Information System (INIS)

Fazeli, M.; Firoozi, F.

2002-01-01

It well established that myocardial perfusion SPECT with 201 T L or 99 mTc-se sta mi bi play an important role diagnosis and risk assessment in patients with known or suspected coronary artery disease. Both quantitative and qualitative methods are available for interpretation of images. The use of a semi quantitative scoring system in which each of 20 segments is scored according to a five-point scheme provides an approach to interpretation that is more systematic and reproducible than simple qualitative evaluation. Only a limited number of studies have dealt with the interpretive observer reproducibility of 99 mTc-steamboat's myocardial perfusion imaging. The aim of this study was to assess the intra-and inter observer variability of semi quantitative SPECT performed with this technique. Among 789 patients that underwent myocardial perfusion SPECT during last year 80 patients finally need to coronary angiography as gold standard. In this group of patients a semi quantitative visual interpretation was carried out using short axis and vertical long-axis myocardial tomograms and a 20-segments model. These segments we reassigned on six evenly spaced regions in the apical, mid-ventricular, and basal short-axis view and two apical segments on the mid-ventricular long-axis slice. Uptake in each segment was graded on a 5-point scale (0=normal, 1=equivocal, 2=moderate, 3=severe, 4=absence of uptake). The steamboat's images was interpreted separately w ice by two observers without knowledge of each other's findings or results of angiography. A SPECT study was judged abnormal if there were two or more segments with a stress score equal or more than 2. We con eluded that semi-quantitative visual analysis is a simple and reproducible method of interpretation

HREM study of Bi-oxide based high Tc superconductors

International Nuclear Information System (INIS)

Hewat, E.A.

1988-01-01

A HREM study of the superstructure and structural defects in Bi 2-x Pb x Sr 2 CaCu 2 O 8 and Bi 2-x Pb x (SrCa) 2 CuO 6 (for x=0 and x=0.4) is presented. The superstructures are shown to involve waves of distortion along the b-axis. These waves are locked on to the lattice positions so that they have a local wave length of 4,5,6,7 or 8 times the basic unit cell. The superstructures are composed of roughly periodic combinations of these basic building blocks (waves). The lead doped superconductors show a less pronounced but more complicated superstructure along b where two distinct periodicities close to 4 and 7 times the basic unit cell predominate. In each of the compounds studied the superstructure, in the better ordered crystals, is shown to be commensurate with a unit cell between 5 and 23 times the basic unit cell. The superstructure in Bi 2-x Pb x Sr 2 CaCu 2 O 8 is orthorhombic where as the superstructure in Bi 2-x Pb x (SrCa) 2 CuO 6 is monoclinic. All these superconductors have a low ''twin'' density (ie density of 90 0 twist boundaries). They exhibit many dislocations and dislocation arrays associated with the weak bonding between BiO planes. They also form non-stoechiometric stacking faults with local changes in the c-axis spacing between layers

ADVANCED CLUSTER BASED IMAGE SEGMENTATION

Directory of Open Access Journals (Sweden)

D. Kesavaraja

2011-11-01

Full Text Available This paper presents efficient and portable implementations of a useful image segmentation technique which makes use of the faster and a variant of the conventional connected components algorithm which we call parallel Components. In the Modern world majority of the doctors are need image segmentation as the service for various purposes and also they expect this system is run faster and secure. Usually Image segmentation Algorithms are not working faster. In spite of several ongoing researches in Conventional Segmentation and its Algorithms might not be able to run faster. So we propose a cluster computing environment for parallel image Segmentation to provide faster result. This paper is the real time implementation of Distributed Image Segmentation in Clustering of Nodes. We demonstrate the effectiveness and feasibility of our method on a set of Medical CT Scan Images. Our general framework is a single address space, distributed memory programming model. We use efficient techniques for distributing and coalescing data as well as efficient combinations of task and data parallelism. The image segmentation algorithm makes use of an efficient cluster process which uses a novel approach for parallel merging. Our experimental results are consistent with the theoretical analysis and practical results. It provides the faster execution time for segmentation, when compared with Conventional method. Our test data is different CT scan images from the Medical database. More efficient implementations of Image Segmentation will likely result in even faster execution times.

Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis.

Science.gov (United States)

Held, Christian; Nattkemper, Tim; Palmisano, Ralf; Wittenberg, Thomas

2013-01-01

Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline's modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum.

Approaches to automatic parameter fitting in a microscopy image segmentation pipeline: An exploratory parameter space analysis

Directory of Open Access Journals (Sweden)

Christian Held

2013-01-01

Full Text Available Introduction: Research and diagnosis in medicine and biology often require the assessment of a large amount of microscopy image data. Although on the one hand, digital pathology and new bioimaging technologies find their way into clinical practice and pharmaceutical research, some general methodological issues in automated image analysis are still open. Methods: In this study, we address the problem of fitting the parameters in a microscopy image segmentation pipeline. We propose to fit the parameters of the pipeline′s modules with optimization algorithms, such as, genetic algorithms or coordinate descents, and show how visual exploration of the parameter space can help to identify sub-optimal parameter settings that need to be avoided. Results: This is of significant help in the design of our automatic parameter fitting framework, which enables us to tune the pipeline for large sets of micrographs. Conclusion: The underlying parameter spaces pose a challenge for manual as well as automated parameter optimization, as the parameter spaces can show several local performance maxima. Hence, optimization strategies that are not able to jump out of local performance maxima, like the hill climbing algorithm, often result in a local maximum.

The influence of nanoscale heterostructures on the thermoelectric properties of bi-substituted Tl{sub 5}Te{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Heinke, Frank; Schlegel, Robert; Schwarzmueller, Stefan; Oeckler, Oliver [Institute for Mineralogy, Crystallography, and Materials Science, Faculty of Chemistry and Mineralogy, Leipzig University (Germany); Eisenburger, Lucien [University of Munich (LMU), Department Chemie (Germany)

2017-03-16

Tl{sub 4.5}Bi{sub 0.5}Te{sub 3} crystallizes in a distorted variant of the Tl{sub 5}Te{sub 3} structure type in the space group I4/m. The symmetry reduction compared to Tl{sub 5}Te{sub 3} (space group I4/mcm) is a consequence of cation ordering as shown by resonant X-ray scattering using synchrotron radiation. Tl and Bi predominantly occupy one Wyckoff site each. This ordering is accompanied by displacements of Te atoms. The influence of nanostructuring on the thermoelectric performance of Tl{sub 4.5}Bi{sub 0.5}Te{sub 3} was investigated for the new composite model system Tl{sub 4.5}Bi{sub 0.5}Te{sub 3} - TlInTe{sub 2}. For the nominal composition (Tl{sub 4.5}Bi{sub 0.5}Te{sub 3}){sub 0.6}(TlInTe{sub 2}){sub 0.4}, the thermoelectric Figure of merit ZT reaches 0.8 at 325 C. Nanoscaled precipitates with sizes of about 100-200 nm probably have beneficial influence on the thermal conductivity at this temperature. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

Energy Technology Data Exchange (ETDEWEB)

Cui, J., E-mail: jun.cui@pnnl.gov; Choi, J. P.; Li, G.; Polikarpov, E.; Darsell, J. [Energy and Environment Directorate, Pacific Northwest National Laboratory, Richland, Washington 99354 (United States); Kramer, M. J.; Zarkevich, N. A.; Wang, L. L.; Johnson, D. D. [Materials Sciences and Engineering Division, Ames Laboratory, Ames, Iowa 50011 (United States); Marinescu, M. [Electron Energy Corporation, Landisville, Pennsylvania 17538 (United States); Huang, Q. Z.; Wu, H. [NIST Center for Neutron Research, National Institute of Standards and Technology, Gaithersburg, Maryland 20899-6102 (United States); Vuong, N. V.; Liu, J. P. [Department of Physics, University of Texas at Arlington, Arlington, Texas 76019 (United States)

2014-05-07

MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 μ{sub B} at 50 K and 300 K, respectively.

Development of MnBi permanent magnet: Neutron diffraction of MnBi powder

Energy Technology Data Exchange (ETDEWEB)

Cui, J; Choi, JP; Li, G; Polikarpov, E; Darsell, J; Kramer, MJ; Zarkevich, NA; Wang, LL; Johnson, DD; Marinescu, M; Huang, QZ; Wu, H; Vuong, NV; Liu, JP

2014-05-07

MnBi attracts great attention in recent years for its great potential as permanent magnet materials. MnBi phase is difficult to obtain because of the rather drastic peritectic reaction between Mn and Bi. In this paper, we report our effort on synthesizing high purity MnBi compound using conventional powder metallurgical approaches. Neutron diffraction was carried out to investigate the crystal and nuclear structure of the obtained powder. The result shows that the purity of the obtained powder is about 91 wt. % at 300 K, and the magnetic moment of the Mn atom in MnBi lattice is 4.424 and 4.013 mu(B) at 50 K and 300 K, respectively. (C) 2014 AIP Publishing LLC.

Hierarchical spatial genetic structure in a distinct population segment of greater sage-grouse

Science.gov (United States)

Oyler-McCance, Sara J.; Casazza, Michael L.; Fike, Jennifer A.; Coates, Peter S.

2014-01-01

Greater sage-grouse (Centrocercus urophasianus) within the Bi-State Management Zone (area along the border between Nevada and California) are geographically isolated on the southwestern edge of the species’ range. Previous research demonstrated that this population is genetically unique, with a high proportion of unique mitochondrial DNA (mtDNA) haplotypes and with significant differences in microsatellite allele frequencies compared to populations across the species’ range. As a result, this population was considered a distinct population segment (DPS) and was recently proposed for listing as threatened under the U.S. Endangered Species Act. A more comprehensive understanding of the boundaries of this genetically unique population (where the Bi-State population begins) and an examination of genetic structure within the Bi-State is needed to help guide effective management decisions. We collected DNA from eight sampling locales within the Bi-State (N = 181) and compared those samples to previously collected DNA from the two most proximal populations outside of the Bi-State DPS, generating mtDNA sequence data and amplifying 15 nuclear microsatellites. Both mtDNA and microsatellite analyses support the idea that the Bi-State DPS represents a genetically unique population, which has likely been separated for thousands of years. Seven mtDNA haplotypes were found exclusively in the Bi-State population and represented 73 % of individuals, while three haplotypes were shared with neighboring populations. In the microsatellite analyses both STRUCTURE and FCA separate the Bi-State from the neighboring populations. We also found genetic structure within the Bi-State as both types of data revealed differences between the northern and southern part of the Bi-State and there was evidence of isolation-by-distance. STRUCTURE revealed three subpopulations within the Bi-State consisting of the northern Pine Nut Mountains (PNa), mid Bi-State, and White Mountains (WM) following a

Pitch Synchronous Segmentation of Speech Signals

Data.gov (United States)

National Aeronautics and Space Administration — The Pitch Synchronous Segmentation (PSS) that accelerates speech without changing its fundamental frequency method could be applied and evaluated for use at NASA....

Segmentation of radiologic images with self-organizing maps: the segmentation problem transformed into a classification task

Science.gov (United States)

Pelikan, Erich; Vogelsang, Frank; Tolxdorff, Thomas

1996-04-01

The texture-based segmentation of x-ray images of focal bone lesions using topological maps is introduced. Texture characteristics are described by image-point correlation of feature images to feature vectors. For the segmentation, the topological map is labeled using an improved labeling strategy. Results of the technique are demonstrated on original and synthetic x-ray images and quantified with the aid of quality measures. In addition, a classifier-specific contribution analysis is applied for assessing the feature space.

Structural, magnetic and dielectric properties of Pr-modified BiFeO3 multiferroic

International Nuclear Information System (INIS)

Varshney, Dinesh; Sharma, Poorva; Satapathy, S.; Gupta, P.K.

2014-01-01

Graphical abstract: -- Highlights: • BFO and Bi 0.95 Pr 0.05 FeO 3 prepared successfully via solid state reaction route. • XRD confirms rhombohedral structure with space group R3c. • Relaxation process is attributed to thermal motion and hopping of V O 2+ . • Magnetization is enhanced in Bi 0.95 Pr 0.05 FeO 3 sample. • Enhanced magnetization stem from suppression of the spiral spin modulation. -- Abstract: The structural, vibrational, magnetic and dielectric properties of polycrystalline BiFeO 3 and Bi 0.95 Pr 0.05 FeO 3 are investigated by combining X-ray diffraction, Raman scattering spectra, magnetometry and dielectric measurements. Structural symmetry with rhombohedral R3c phase is revealed for both parent and 5% Pr substitution at Bi site, serving no chemical pressure and causes no structural transition from R3c to any other phase is identified from X-ray diffraction patterns and Raman scattering spectra. The shifting of phonon modes towards higher frequency side is attributed to lower atomic mass of Pr ion as compared to Bi ion. The magnetic measurements at room temperature indicate that Pr substitution induces ferromagnetism and discerns large and non-zero remnant magnetization as compare to pristine BiFeO 3 . Both dielectric permittivity and loss factor of Bi 0.95 Pr 0.05 FeO 3 strongly decreases with increased frequency. Significant role of hopping of oxygen ion vacancies in Bi 0.95 Pr 0.05 FeO 3 is inferred from modulus spectra and ac conductivity analysis

Global EiBI-monopole

Directory of Open Access Journals (Sweden)

JIN Xinghua

2014-04-01

Full Text Available A global EiBI-monopole problem is studied under EiBI gravitational theory.The equations of global EiBI-monopole are derived in the curved spacetime and the relation between the spacetime metric and auxiliary metric is found.In the case of a very small parameter,an asymptotic form of equations is given.The series solutions of global EiBI-monopole at infinity are found.

Synthesis, crystal structure and optical properties of BiMgVO 5

Science.gov (United States)

Benmokhtar, S.; El Jazouli, A.; Chaminade, J. P.; Gravereau, P.; Guillen, F.; de Waal, D.

2004-11-01

The new vanadate BiMgVO 5 has been prepared and its structure has been determined by single crystal X-ray diffraction: space group P21/n, a=7.542(6) Å, b=11.615(5) Å, c=5.305(3) Å, β=107.38(5)°, wR2=0.0447, R=0.0255. The structure consists of [Mg 2O 10] and [Bi 2O 10] dimers sharing their corners with [VO 4] tetrahedra. The ranges of bond lengths are 2.129-2.814 Å for Bi-O; 2.035-2.167 Å for Mg-O and 1.684-1.745 Å for V-O. V-O bond lengths determined from Raman band wavenumbers are between 1.679 and 1.747 Å. An emission band overlapping the entire visible region with a maximum around 650 nm is observed.

Determining metal ion distributions using resonant scattering at very high-energy K-edges: Bi/Pb in Pb{sub 5}Bi{sub 6}Se{sub 14}

Energy Technology Data Exchange (ETDEWEB)

Yuegang, Zhang; Lee, P L; Shastri, S D; Deming, Shu [Argonne National Lab., IL (United States). XOR, Advanced Photon Source; Wilkinson, A P [Georgia Inst. of Tech., Atlanta (United States). School of Chemistry and Biochemistry; Duck-Young, Chung; Kanatzidis, M G [Michigan State Univ., East Lansing (United States). Dept. of Chemistry

2005-06-01

Powder diffraction data collected at {proportional_to} 86 keV, and just below both the Pb and the Bi K-edges, on an imaging plate detector using synchrotron radiation from the Advanced Photon Source have been used to examine the Pb/Bi distribution over the 11 crystallographically distinct sites in Pb{sub 5}Bi{sub 6}Se{sub 14} [space group P2{sub 1}/m, a=16.0096(2) Aa, b=4.20148(4) Aa, c=21.5689(3) Aa and {beta}=97.537(1){sup 0}]. The scattering factors needed for the analyses were determined both by Kramers- Kronig transformation of absorption spectra and by analyses of diffraction patterns from reference compounds. Even with the relatively low scattering contrast that is available at the K-edges, it was possible to determine the Pb/Bi distribution and probe the presence of cation site vacancies in the material. The current results indicate that resonant scattering measurements at high-energy K-edges are a viable, and perhaps preferable, route to site occupancies when absorption from the sample or sample environment/container is a major barrier to the acquisition of high-quality resonant scattering data at lower-energy edges.

Facile synthesis, structure elucidation, and magnetic properties of perovskite BaTb{sub 1-x}Bi{sub x}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Farid, Muhammad Asim; Zhang, Hao; Li, Guobao; Liao, Fuhui; Lin, Jianhua [Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, 100871, Beijing (China); Yang, Aimei [College of Materials Science and Engineering, Guilin University of Technology, 541004, Guilin (China); Tian, Gengfang; Wu, Meimei [Neutron Scattering Laboratory, Department of Nuclear Physics, China Institute of Atomic Energy, 102413, Beijing (China)

2017-03-17

A series of perovskite BaTb{sub 1-x}Bi{sub x}O{sub 3} (0.0 ≤ x ≤ 0.25) solid solutions were synthesized by a typical solid-state method. Their structures were analyzed by a combination of X-ray diffraction, neutron diffraction, and selected-area electron diffraction. All of the materials crystalize in the P1 space group [a = 6.0582(1) Aa, b = 6.0473(1) Aa, c = 6.0693(1) Aa, α = 60.00(1) , β = 59.84(1) , γ = 60.06(1) for x = 0.0 at room temperature]. Magnetic measurements revealed that the magnetic-ordering temperature decreases with increasing Bi content in BaTb{sub 1-x}Bi{sub x}O{sub 3}; therefore, the presence of Bi decreases the magnetic interactions of Tb. Furthermore, the magnetic structure for BaTb{sub 1-x}Bi{sub x}O{sub 3} has been fully described in space group P1. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

The conductivity of Bi(111) investigated with nanoscale four point probes

DEFF Research Database (Denmark)

Wells, J.W.; Handrup, K.; Kallehauge, J.F.

2008-01-01

The room temperature conductance of Bi(111) was measured using microscopic four point probes with a contact spacing down to 500 nm. The conductance is remarkably similar to that of the bulk, indicating that surface scattering is not a major mechanism for restricting the mobility at this length...... scale. Also, the high density of electronic surface states on Bi(111) does not appear to have a major influence on the measured conductance. The lower limit for the resistivity due to electronic surface states is found to be around 5 Omega. With such a value for the surface resistivity, surface...

Investigation of the crystal structure of a basic bismuth(III) nitrate with the composition [Bi6O4(OH)(4)](0.54(1))[Bi6O5(OH)(3)](0.46(1))(NO3)(5.54(1))

DEFF Research Database (Denmark)

Christensen, Axel Norlund; Lebech, Bente

2012-01-01

A basic bismuth(III) nitrate with the composition [Bi6O4(OH)(4)](0.5)[Bi6O5(OH)(3)](0.5)(NO3)(5.5) formed in a slow crystal growth mode has an ordered crystal structure with the monoclinic space group P2(1) and lattice parameters a = 15.850(3), b = 14.986(3), c = 18.230(4) angstrom, beta = 107...... a trigonal R (3) over bar cell with a = 15.1865(1) and c = 15.8416(1) angstrom (hexagonal setting). In a Rietveld type structure model refinement with a total of 28 atom sites (4 Bi, 3 N, 15 O and 6 H), the composition of this sample is determined to be [Bi6O4(OH)(4)](0.54(1))[Bi6O5(OH)(3)](0.46(1))(NO3)(5.54(1))....

Data Transformation Functions for Expanded Search Spaces in Geographic Sample Supervised Segment Generation

OpenAIRE

Christoff Fourie; Elisabeth Schoepfer

2014-01-01

Sample supervised image analysis, in particular sample supervised segment generation, shows promise as a methodological avenue applicable within Geographic Object-Based Image Analysis (GEOBIA). Segmentation is acknowledged as a constituent component within typically expansive image analysis processes. A general extension to the basic formulation of an empirical discrepancy measure directed segmentation algorithm parameter tuning approach is proposed. An expanded search landscape is defined, c...

Scorpion image segmentation system

Science.gov (United States)

Joseph, E.; Aibinu, A. M.; Sadiq, B. A.; Bello Salau, H.; Salami, M. J. E.

2013-12-01

Death as a result of scorpion sting has been a major public health problem in developing countries. Despite the high rate of death as a result of scorpion sting, little report exists in literature of intelligent device and system for automatic detection of scorpion. This paper proposed a digital image processing approach based on the floresencing characteristics of Scorpion under Ultra-violet (UV) light for automatic detection and identification of scorpion. The acquired UV-based images undergo pre-processing to equalize uneven illumination and colour space channel separation. The extracted channels are then segmented into two non-overlapping classes. It has been observed that simple thresholding of the green channel of the acquired RGB UV-based image is sufficient for segmenting Scorpion from other background components in the acquired image. Two approaches to image segmentation have also been proposed in this work, namely, the simple average segmentation technique and K-means image segmentation. The proposed algorithm has been tested on over 40 UV scorpion images obtained from different part of the world and results obtained show an average accuracy of 97.7% in correctly classifying the pixel into two non-overlapping clusters. The proposed 1system will eliminate the problem associated with some of the existing manual approaches presently in use for scorpion detection.

Radiomic modeling of BI-RADS density categories

Science.gov (United States)

Wei, Jun; Chan, Heang-Ping; Helvie, Mark A.; Roubidoux, Marilyn A.; Zhou, Chuan; Hadjiiski, Lubomir

2017-03-01

Screening mammography is the most effective and low-cost method to date for early cancer detection. Mammographic breast density has been shown to be highly correlated with breast cancer risk. We are developing a radiomic model for BI-RADS density categorization on digital mammography (FFDM) with a supervised machine learning approach. With IRB approval, we retrospectively collected 478 FFDMs from 478 women. As a gold standard, breast density was assessed by an MQSA radiologist based on BI-RADS categories. The raw FFDMs were used for computerized density assessment. The raw FFDM first underwent log-transform to approximate the x-ray sensitometric response, followed by multiscale processing to enhance the fibroglandular densities and parenchymal patterns. Three ROIs were automatically identified based on the keypoint distribution, where the keypoints were obtained as the extrema in the image Gaussian scale-space. A total of 73 features, including intensity and texture features that describe the density and the parenchymal pattern, were extracted from each breast. Our BI-RADS density estimator was constructed by using a random forest classifier. We used a 10-fold cross validation resampling approach to estimate the errors. With the random forest classifier, computerized density categories for 412 of the 478 cases agree with radiologist's assessment (weighted kappa = 0.93). The machine learning method with radiomic features as predictors demonstrated a high accuracy in classifying FFDMs into BI-RADS density categories. Further work is underway to improve our system performance as well as to perform an independent testing using a large unseen FFDM set.

Visual Sensor Based Image Segmentation by Fuzzy Classification and Subregion Merge

Directory of Open Access Journals (Sweden)

Huidong He

2017-01-01

Full Text Available The extraction and tracking of targets in an image shot by visual sensors have been studied extensively. The technology of image segmentation plays an important role in such tracking systems. This paper presents a new approach to color image segmentation based on fuzzy color extractor (FCE. Different from many existing methods, the proposed approach provides a new classification of pixels in a source color image which usually classifies an individual pixel into several subimages by fuzzy sets. This approach shows two unique features: the spatial proximity and color similarity, and it mainly consists of two algorithms: CreateSubImage and MergeSubImage. We apply the FCE to segment colors of the test images from the database at UC Berkeley in the RGB, HSV, and YUV, the three different color spaces. The comparative studies show that the FCE applied in the RGB space is superior to the HSV and YUV spaces. Finally, we compare the segmentation effect with Canny edge detection and Log edge detection algorithms. The results show that the FCE-based approach performs best in the color image segmentation.

High photocatalytic performance of BiOI/Bi{sub 2}WO{sub 6} toward toluene and Reactive Brilliant Red

Energy Technology Data Exchange (ETDEWEB)

Li Huiquan [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China); Key Laboratory of Mesoscopic Chemistry of MOE, Jiangsu Provincial Key Laboratory of Nanotechnology, School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210093 (China); Cui Yumin, E-mail: cuiyumin0908@163.com [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China); Hong Wenshan [School of Chemistry and Chemical Engineering, Fuyang Normal College, Fuyang 236041 (China)

2013-01-01

Graphical abstract: When BiOI/Bi{sub 2}WO{sub 6} catalyst was exposed to UV or visible light, the electrons in the valence band of Bi{sub 2}WO{sub 6} would be excited into the conduction band and then injected into the more positive conduction band of BiOI. Therefore, the photoelectrons were generated from Bi{sub 2}WO{sub 6} and transferred across the interface between BiOI and Bi{sub 2}WO{sub 6} to the surface of BiOI, leaving the photogenerated holes in the valence band of Bi{sub 2}WO{sub 6}. In this way, the photoinduced electron-hole pairs were effectively separated. Highlights: Black-Right-Pointing-Pointer BiOI sensitized Bi{sub 2}WO{sub 6} catalysts were successfully prepared by a facile method. Black-Right-Pointing-Pointer The 13.2% BiOI/Bi{sub 2}WO{sub 6} catalyst exhibits higher photoactivities than P25. Black-Right-Pointing-Pointer A possible transfer process of photogenerated carriers was proposed. - Abstract: BiOI sensitized nano-Bi{sub 2}WO{sub 6} photocatalysts with different BiOI contents were successfully synthesized by a facile deposition method at room temperature, and characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) high-resolution transmission electron microscopy (HR-TEM), photoluminescence (PL) spectra, UV-vis diffuse reflection spectroscopy (UV-vis DRS) and Brunauer-Emmett-Teller (BET) surface area measurements. The photocatalytic activity of BiOI/Bi{sub 2}WO{sub 6} was evaluated by the photo-degradation of Reactive Brilliant Red (X-3B) in suspended solution and toluene in gas phase. It has been shown that the BiOI/Bi{sub 2}WO{sub 6} catalysts exhibit a coexistence of both tetragonal BiOI and orthorhombic Bi{sub 2}WO{sub 6} phases. With increasing BiOI content, the absorption intensity of BiOI/Bi{sub 2}WO{sub 6} catalysts increases in the 380-600 nm region and the absorption edge shifts significantly to longer wavelengths as compared to pure Bi{sub 2}WO{sub 6}. The 13.2% BiOI/Bi{sub 2}WO{sub 6} catalyst exhibits

Rapid adsorption properties of flower-like BiOI nanoplates synthesized via a simple EG-assisted solvothermal process

Energy Technology Data Exchange (ETDEWEB)

Zhang, Bin; Ji, Guangbin, E-mail: gbji@nuaa.edu.cn [Nanjing University of Aeronautics and Astronautics, College of Materials Science and Technology (China); Gondal, M. A. [King Fahd University of Petroleum and Minerals, Physics Department (Saudi Arabia); Liu, Yousong; Zhang, Xingmiao; Chang, Xiaofeng; Li, Nianwu [Nanjing University of Aeronautics and Astronautics, College of Materials Science and Technology (China)

2013-07-15

Uniform well-crystallized flower-like BiOI nanoplates contained 3.7 nm mesopores, which may be attributed to the internanosheet spaces of BiOI with maximum pore diameters of about 30 nm, were successfully synthesized via a simple ethylene glycol-assisted solvothermal method. The as-prepared porous BiOI nanoplates exhibited excellent adsorption ability, and the saturated extent of adsorption of BiOI over an RhB solution was as high as 197 mg/g, which is much higher than those for BiOCl and BiOBr prepared via the same method and with a similar surface area. The probable adsorption mechanism could have originated from the interaction between the I atom in BiOI and a proton in RhB at different pH values and temperatures. With visible light irradiation ({lambda} > 420 nm), 80 % of the RhB was degraded in 4 h, while BiOI still demonstrated reasonably outstanding photocatalytic ability under green light ({lambda} = 550 {+-} 15 nm) because of its low-energy gap (1.72 eV). The degradation test for BiOI under irradiation at {lambda} = 550 {+-} 15 nm is an excellent achievement for field applications because the catalyst can be applied in solar irradiation to remove organic pollutants, which may be of great value BiOI complex.

MLED_BI: a new BI Design Approach to Support Multilingualism in Business Intelligence

Directory of Open Access Journals (Sweden)

Nedim Dedić

2017-11-01

Full Text Available Existing approaches to support Multilingualism (ML in Business Intelligence (BI create problems for business users, present a number of challenges from the technical perspective, and lead to issues with logical dependence in the star schema. In this paper, we propose MLED_BI (Multilingual Enabled Design for Business Intelligence, a novel BI design approach to support the application of ML in BI Environment, which overcomes the issues and problems found with existing approaches. The approach is based on a revision of the data warehouse dimensional modelling approach and treats the Star Schema as a higher level entity. This paper describes MLED_BI and the validation and evaluation approach used.

Ga-Bi-Te system

International Nuclear Information System (INIS)

Rustamov, P.G.; Seidova, N.A.; Shakhbazov, M.G.; AN Azerbajdzhanskoj SSR, Baku. Inst. Neorganicheskoj i Fizicheskoj Khimii)

1976-01-01

To elucidate the nature of interaction in the system Ga-Bi-Te, a study has been made of sections GaTe-Bi 2 Te 3 , Ga 2 Te 3 -Bi, GaTe-Bi and Bi 2 Te 3 -Ga. The alloys have been prepared by direct melting of the components or their alloys with subsequent homogenizin.o annealing at 400 deg C. The study has been made by the methods of differential thermal, microstructural analysis and by microhardness measurements. On the basis of literature data and data obtained a projection of the liquidus surface of the phase diagram for the system Ga-Bi-Te has been constructed. In the ternary system there are 17 curves of monovariant equilibrium dividing the liquidus into 10 fields of primary crystallization of phases, 9 points of non-variant equilibrium of which 4 points are triple eutectics and 5 points are triple peritectics

Overlayer growth and electronic properties of the Bi/GaSb(110) interface

Science.gov (United States)

Gavioli, Luca; Betti, Maria Grazia; Casarini, Paolo; Mariani, Carlo

1995-06-01

The overlayer growth and electronic properties of the Bi/GaSb(110) interface and of the two-dimensional ordered (1×1)- and (1×2)-Bi layers have been investigated by complementary spectroscopic techniques (high-resolution electron-energy-loss, photoemission, and Auger spectroscopy). Bismuth forms an epitaxial monolayer, followed by island formation (Stranski-Krastanov growth mode) covering an average surface area of 40% at a nominal coverage of 4 ML. The (1×2)-symmetry stable structural phase, obtained after annealing at ~220 °C, corresponds to an average nominal Bi coverage of about 0.7 ML, suggesting an atomic geometry different from the epitaxial-continued layer structure. The disposal of Bi atoms in the (1×2) structure should build up an ``open'' layer, as the Ga-related surface exciton quenched in the (1×1) epitaxial monolayer is present in the (1×2) stable phase. The two symmetry phases are characterized by strong absorption features at 1 eV [(1×1)-Bi] and 0.54 eV [(1×2)-Bi], related to interband electronic transitions between Bi-induced electronic states. The major Bi-related occupied electronic levels, present in the valence band of the (1×1)- and (1×2)-Bi layer, have been detected by angle-integrated ultraviolet photoemission spectroscopy. Both the (1×1) and (1×2) phases show a metallic nature, with a low density of electronic states at the Fermi level. Schottky barrier heights of 0.20 and 0.14 eV are estimated for the epitaxial (1×1)- and (1×2)-symmetry stage, respectively, by analyzing the space-charge layer conditions through the study of the dopant-induced free-carrier plasmon in the GaSb substrate.

The non-target bi-ovarian branches occlusion in fibroids embolization on resumption of menses and ovarian function

International Nuclear Information System (INIS)

Guo Wenbo; Yang Jianyong; Chen Wei; Zhuang Wenquan; Yao Shuzhong

2005-01-01

Objective: To evaluate the effect of the non-target bi-ovarian branches occlusion in fibroids embolization on resumption of menses and ovarian function. Methods: The patients with the non-target bi-ovarian branches occlusion in uterine fibroids embolization (UFE) were classified into two groups, one for lipiodol deposited in bi-ovarian areas (Group A) , another for non lipiodol deposited in ovarian areas or in single ovarian area (Group B of non lipiodol deposited in bi-ovarian areas). The statistical difference between the data of group A and group B were assessed with Fisher test. All UFE were performed with the mixture of lipiodol and pingyangmycin. The serum level of Follicle stimulating hormone (FSH), luteinizing hormone (LH) and estradiol (E2) were measured before UFE and 6 months after UFE. The statistical difference between the data of before and after UFE was assessed with t test. Results: Fifteen patients [age ranged 26-46 years, average (39.00 ± 5.62) years] had been followed up for an average (30.5±6.4) months (range 16-47 months). In 12 of 15, regular menses resumed after an average of (3.0 ±0.3) weeks (range 2-6 weeks). In 3 of 15 (20%), regular menses did not resume. The sexual hormone findings of menopause were found in three cases with amenorrhea after UFE. Amenorrhea was found in three cases with lipiodol deposited in bi-ovarian areas (Group A). Non-amenorrhea was found in the group of non-lipiodol deposited in bi-ovarian areas (Group B). There were significant statistical difference between Group A and Group B (P=0.002 19). Non amenorrhea was found in the patients aged over 45 years old. Three patients were found amenorrhea in the patients aged younger than 45 years old. There were no significant statistical difference between the serum level of FSH, LH and E2 before and 6 months after UFE (P>0.05). Conclusion: The incidence of amenorrhea is very high in the patients with lipiodol deposited in bi-ovarian areas when the bi-ovarian branches of

Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

International Nuclear Information System (INIS)

Xiong Ka; Wang Weichao; Alshareef, Husam N; Gupta, Rahul P; Gnade, Bruce E; Cho, Kyeongjae; White, John B

2010-01-01

We investigate the electronic structures and stability for Ni/Bi 2 Te 3 , NiTe/Bi 2 Te 3 , Co/Bi 2 Te 3 and CoTe 2 /Bi 2 Te 3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi 2 Te 3 . The interface formation energy for Co/Bi 2 Te 3 interfaces is much lower than that of Ni/Bi 2 Te 3 interfaces. Furthermore, we found that NiTe on Bi 2 Te 3 is more stable than Ni, while the formation energies for Co and CoTe 2 on Bi 2 Te 3 are comparable.

Low-Field Bi-Skyrmion Formation in a Noncentrosymmetric Chimney Ladder Ferromagnet

Science.gov (United States)

Takagi, R.; Yu, X. Z.; White, J. S.; Shibata, K.; Kaneko, Y.; Tatara, G.; Rønnow, H. M.; Tokura, Y.; Seki, S.

2018-01-01

The real-space spin texture and the relevant magnetic parameters were investigated for an easy-axis noncentrosymmetric ferromagnet Cr11 Ge19 with Nowotny chimney ladder structure. Using Lorentz transmission electron microscopy, we report the formation of bi-Skyrmions, i.e., pairs of spin vortices with opposite magnetic helicities. The quantitative evaluation of the magnetocrystalline anisotropy and Dzyaloshinskii-Moriya interaction (DMI) proves that the magnetic dipolar interaction plays a more important role than the DMI on the observed bi-Skyrmion formation. Notably, the critical magnetic field value required for the formation of bi-Skyrmions turned out to be extremely small in this system, which is ascribed to strong easy-axis anisotropy associated with the characteristic helix crystal structure. The family of Nowotny chimney ladder compounds may offer a unique material platform where two distinctive Skyrmion formation mechanisms favoring different topological spin textures can become simultaneously active.

Magnetic structure of the YbMn2SbBi compound

International Nuclear Information System (INIS)

Morozkin, A.V.; Manfrinetti, P.

2011-01-01

Graphical abstract: Display Omitted Research highlights: → A neutron diffraction investigation in zero applied field of La 2 O 2 S-type YbMn 2 SbBi shows antiferromagnetic ordering below 138(3) K and ferrimagnetic ordering below 112(3) K. → Between 138 and 112 K, the magnetic structure of YbMn 2 SbBi consists of antiferromagnetically coupled ab-plane magnetic moments of the manganese atoms (D 1d magnetic point group). → Below 112(3) K, the magnetic structure of YbMn 2 SbBi becames the sum antiferromagnetic component with D 1d magnetic point group and ferromagnetic one with C 2 magnetic point group. → The magnitude of Yb and Mn magnetic moments in YbMn 2 SbBi at 2 K (M Yb = 3.6(2) μ B , M Mn = 3.5(2) μ B ) correspond to the trivalent state of the Yb ions and tetravalent state of the Mn ions. - Abstract: A neutron diffraction investigation has been carried out on the trigonal La 2 O 2 S-type (hP5, space group P3-bar ml, No. 164; also CaAl 2 Si 2 -type) YbMn 2 SbBi intermetallic compound. The YbMn 2 SbBi presents antiferromagnetic ordering below 138(3) K and ferrimagnetic ordering below 112(3) K. Between 138 and 112 K, the magnetic structure of YbMn 2 SbBi consists of antiferromagnetically coupled ab-plane magnetic moments of the manganese atoms (D 1d magnetic point group). Below 112(3) K, the ferromagnetic components of Yb and Mn begin to develop, and the magnetic structure of YbMn 2 SbBi becames the sum antiferromagnetic component with D 1d magnetic point group and ferromagnetic one with C 2 magnetic point group. The magnitude of Yb and Mn magnetic moments in YbMn 2 SbBi at 2 K (M Yb = 3.6(2) μ B , M Mn = 3.5(2) μ B ) correspond to the trivalent state of the Yb ions and tetravalent state of the Mn ions.

Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

KAUST Repository

Xiong, Ka; Wang, Weichao; Alshareef, Husam N.; Gupta, Rahul P.; White, John B.; Gnade, Bruce E.; Cho, Kyeongjae

2010-01-01

We investigate the electronic structures and stability for Ni/Bi 2Te3, NiTe/Bi2Te3, Co/Bi 2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable. © 2010 IOP Publishing Ltd.

Electronic structures and stability of Ni/Bi2Te3 and Co/Bi2Te3 interfaces

KAUST Repository

Xiong, Ka

2010-03-04

We investigate the electronic structures and stability for Ni/Bi 2Te3, NiTe/Bi2Te3, Co/Bi 2Te3 and CoTe2/Bi2Te3 interfaces by first-principles calculations. It is found that the surface termination strongly affects the band alignment. Ni and Co are found to form Ohmic contacts to Bi2Te3. The interface formation energy for Co/Bi2Te3 interfaces is much lower than that of Ni/Bi2Te3 interfaces. Furthermore, we found that NiTe on Bi2Te3 is more stable than Ni, while the formation energies for Co and CoTe2 on Bi2Te3 are comparable. © 2010 IOP Publishing Ltd.

Bismuth-boron multiple bonding in BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -}

Energy Technology Data Exchange (ETDEWEB)

Jian, Tian; Cheung, Ling Fung; Chen, Teng-Teng; Wang, Lai-Sheng [Department of Chemistry, Brown University, Providence, RI (United States)

2017-08-01

Despite its electron deficiency, boron is versatile in forming multiple bonds. Transition-metal-boron double bonding is known, but boron-metal triple bonds have been elusive. Two bismuth boron cluster anions, BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -}, containing triple and double B-Bi bonds are presented. The BiB{sub 2}O{sup -} and Bi{sub 2}B{sup -} clusters are produced by laser vaporization of a mixed B/Bi target and characterized by photoelectron spectroscopy and ab initio calculations. Well-resolved photoelectron spectra are obtained and interpreted with the help of ab initio calculations, which show that both species are linear. Chemical bonding analyses reveal that Bi forms triple and double bonds with boron in BiB{sub 2}O{sup -} ([Bi≡B-B≡O]{sup -}) and Bi{sub 2}B{sup -} ([Bi=B=Bi]{sup -}), respectively. The Bi-B double and triple bond strengths are calculated to be 3.21 and 4.70 eV, respectively. This is the first experimental observation of Bi-B double and triple bonds, opening the door to design main-group metal-boron complexes with multiple bonding. (copyright 2017 Wiley-VCH Verlag GmbH and Co. KGaA, Weinheim)

Photocatalytic activity of Bi{sub 2}WO{sub 6}/Bi{sub 2}S{sub 3} heterojunctions: the facilitation of exposed facets of Bi{sub 2}WO{sub 6} substrate

Energy Technology Data Exchange (ETDEWEB)

Yan, Long [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China); Wang, Yufei [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); Shen, Huidong; Zhang, Yu [School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China); Li, Jian [School of Chemistry and Chemical Engineering, Yulin University, Shaanxi Key Laboratory of Low Metamorphic Coal Clean Utilization, Yulin 71900 (China); Wang, Danjun, E-mail: yulyanlong@aliyun.com [School of Chemistry and Chemical Engineering, Yan’an University, Shaanxi Key Laboratory of Chemical Reaction Engineering, Yan’an 716000 (China)

2017-01-30

Highlights: • Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} hybrids with exposed (020) Bi{sub 2}WO{sub 6} facets have been synthesized. • X-ray photoelectron spectroscopy reveals that a small amount of Bi{sub 2}S{sub 3} was formed. • The enhanced photoactivity of hybrids is due to heterojunction and (020) facets. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} hybrid architectures with exposed (020) Bi{sub 2}WO{sub 6} facets have been synthesized via a controlled anion exchange approach. X-ray photoelectron spectroscopy (XPS) reveals that a small amount of Bi{sub 2}S{sub 3} was formed on the surface of Bi{sub 2}WO{sub 6} during the anion exchange process, thus leading to the transformation from the Bi{sub 2}WO{sub 6} to Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}. A rhodamine B (RhB) aqueous solution was chosen as model organic pollutants to evaluate the photocatalytic activities of the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6} catalysts. Under visible light irradiation, the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}-TAA displayed the excellent visible light photoactivities compared with pure Bi{sub 2}S{sub 3}, Bi{sub 2}WO{sub 6} and other composite photocatalysts. The efficient photocatalytic activity of the Bi{sub 2}S{sub 3}/Bi{sub 2}WO{sub 6}-TAA composite microspheres was ascribed to the constructed heterojunctions and the inner electric field caused by the exposed (020) Bi{sub 2}WO{sub 6} facets. Active species trapping experiments revealed that h{sup +} and O{sub 2}·{sup −} are the main active species in the photocatalytic process. Furthermore, the as-obtained photocatalysts showed good photocatalytic activity after four recycles. The results presented in this study provide a new concept for the rational design and development of highly efficient photocatalysts.

Automatic segmentation of psoriasis lesions

Science.gov (United States)

Ning, Yang; Shi, Chenbo; Wang, Li; Shu, Chang

2014-10-01

The automatic segmentation of psoriatic lesions is widely researched these years. It is an important step in Computer-aid methods of calculating PASI for estimation of lesions. Currently those algorithms can only handle single erythema or only deal with scaling segmentation. In practice, scaling and erythema are often mixed together. In order to get the segmentation of lesions area - this paper proposes an algorithm based on Random forests with color and texture features. The algorithm has three steps. The first step, the polarized light is applied based on the skin's Tyndall-effect in the imaging to eliminate the reflection and Lab color space are used for fitting the human perception. The second step, sliding window and its sub windows are used to get textural feature and color feature. In this step, a feature of image roughness has been defined, so that scaling can be easily separated from normal skin. In the end, Random forests will be used to ensure the generalization ability of the algorithm. This algorithm can give reliable segmentation results even the image has different lighting conditions, skin types. In the data set offered by Union Hospital, more than 90% images can be segmented accurately.

Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO3 thin film

International Nuclear Information System (INIS)

Gupta, Surbhi; Gupta, Vinay; Tomar, Monika; James, A. R.; Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar

2014-01-01

Multiferroic Bismuth Ferrite (BiFeO 3 ) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO 3 thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO 3 and Fe 2 O 3 to pure BiFeO 3 phase and, subsequently, to a mixture of BiFeO 3 and Bi 2 O 3 with increase in the concentration of excess Bi from 0% to 15%. BiFeO 3 thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe 2 O 3 ). Deterioration in ferroic properties of BiFeO 3 thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO 3 thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm 2 and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO 3 thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO 3 thin films exhibiting the improved multiferroic properties.

Ternary rare-earth bismuthides RE5SiBi2 and RE5GeBi2 (RE=La-Nd, Gd-Er): Stabilization of the β-Yb5Sb3-type structure through tetrel substitution

International Nuclear Information System (INIS)

Barry, Stephen D.; Tkachuk, Andriy V.; Bie, Haiying; Blanchard, Peter E.R.; Mar, Arthur

2011-01-01

Ternary bismuthides RE 5 TtBi 2 containing rare-earth (RE=La-Nd, Gd-Er) and tetrel (Tt=Si, Ge) atoms have been prepared by arc-melting of the elements followed by annealing at 800 o C. They adopt the β-Yb 5 Sb 3 -type structure (Pearson symbol oP32, space group Pnma, Z=4), as revealed through analysis by single-crystal X-ray diffraction on Ce 5 Si 0.869(4) Bi 2.131(4) and powder X-ray diffraction on Ce 5 GeBi 2 . Cell parameters for the entire series lie in the ranges of a=12.8-11.8 A, b=9.6-9.0 A, and c=8.4-7.9 A. Solid solubility in Ce 5 Si x Bi 3-x and Pr 5 Si x Bi 3-x (approximately 0.9≤x≤1.2, depending on the RE member) is much more limited compared to the antimonides, consistent with a highly ordered structure in which the two possible anion sites are essentially segregated into a smaller one occupied by Tt atoms (CN7) and a larger one occupied by Bi atoms (CN9). Band structure calculations on La 5 SiBi 2 confirm the importance of La-La bonding interactions near the Fermi level. X-ray photoelectron spectra support the presence of partially anionic Bi atoms, as indicated by a small negative binding energy shift relative to elemental Bi. The Ce and Pr members undergo magnetic transitions at low temperatures, possibly involving ferromagnetic interactions, that are strongly influenced by the nature of the Tt atom. -- Graphical Abstract: Tetrel (Si or Ge) and Bi atoms are arranged in an ordered manner in the β-Yb 5 Sb 3 -type structure adopted by RE 5 TtBi 2 . Display Omitted

Revascularization of diaphyseal bone segments by vascular bundle implantation.

Science.gov (United States)

Nagi, O N

2005-11-01

Vascularized bone transfer is an effective, established treatment for avascular necrosis and atrophic or infected nonunions. However, limited donor sites and technical difficulty limit its application. Vascular bundle transplantation may provide an alternative. However, even if vascular ingrowth is presumed to occur in such situations, its extent in aiding revascularization for ultimate graft incorporation is not well understood. A rabbit tibia model was used to study and compare vascularized, segmental, diaphyseal, nonvascularized conventional, and vascular bundle-implanted grafts with a combination of angiographic, radiographic, histopathologic, and bone scanning techniques. Complete graft incorporation in conventional grafts was observed at 6 months, whereas it was 8 to 12 weeks with either of the vascularized grafts. The pattern of radionuclide uptake and the duration of graft incorporation between vascular segmental bone grafts (with intact endosteal blood supply) and vascular bundle-implanted segmental grafts were similar. A vascular bundle implanted in the recipient bone was found to anastomose extensively with the intraosseous circulation at 6 weeks. Effective revascularization of bone could be seen when a simple vascular bundle was introduced into a segment of bone deprived of its normal blood supply. This simple technique offers promise for improvement of bone graft survival in clinical circumstances.

Topotactic synthesis of a new BiS2-based superconductor Bi2(O,F)S2

OpenAIRE

Okada, Tomoyuki; Ogino, Hiraku; Shimoyama, Jun-ichi; Kishio, Kohji

2015-01-01

A new BiS2-based superconductor Bi2(O,F)S2 was discovered. This is a layered compound consisting of alternate stacking structure of rock-salt-type BiS2 superconducting layer and fluorite-type Bi(O,F) blocking layer. Bi2(O,F)S2 was obtained as the main phase by topotactic fluorination of undoped Bi2OS2 using XeF2, which is the first topotactic synthesis of an electron-doped superconductor via reductive fluorination. With increasing F-content, a- and c-axis length increased and decreased, respe...

Synthesis and crystal structure analysis of titanium bismuthide oxide, Ti{sub 8}BiO{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Amano, Shinsaku; Yamane, Hisanori, E-mail: yamane@tagen.tohoku.ac.jp

2016-08-05

Silver metallic luster columnar single crystals of a novel compound, Ti{sub 8}BiO{sub 7}, were synthesized using a bismuth flux. Ti{sub 8}BiO{sub 7} having a new structure type crystallizes in an orthorhombic cell, a = 7.8473(4) Å, b = 16.8295(10) Å, c = 3.0256(2) Å, space group: Cmmm. The Ti atoms enter the sites of isosceles-triangle 3-fold and rectangular 4-fold coordination of O atoms and the site of octahedral 6-fold coordination of O and Bi atoms. O atoms are in the rectangles, tetrahedra, and orthogonal pyramids of Ti atoms. The electrical resistivity measured for a Ti{sub 8}BiO{sub 7} single crystal in the c-axis direction was 6.2 × 10{sup −7} Ωm at 300 K and 1.3 × 10{sup −7} Ωm at 10 K. - Highlights: • A novel bismuthide oxide containing titanium, Ti{sub 8}BiO{sub 7}, was synthesized. • Single crystals of Ti{sub 8}BiO{sub 7} were grown by heating a mixture of Ti and Bi{sub 2}O{sub 3}. • Single crystal X-ray diffraction revealed that Ti{sub 8}BiO{sub 7} has a new structure type. • O atoms and Bi atoms are surrounded by Ti atoms in the structure. • Metallic conduction of Ti{sub 8}BiO{sub 7} was exhibited.

AN ADAPTIVE APPROACH FOR SEGMENTATION OF 3D LASER POINT CLOUD

Directory of Open Access Journals (Sweden)

Z. Lari

2012-09-01

Full Text Available Automatic processing and object extraction from 3D laser point cloud is one of the major research topics in the field of photogrammetry. Segmentation is an essential step in the processing of laser point cloud, and the quality of extracted objects from laser data is highly dependent on the validity of the segmentation results. This paper presents a new approach for reliable and efficient segmentation of planar patches from a 3D laser point cloud. In this method, the neighbourhood of each point is firstly established using an adaptive cylinder while considering the local point density and surface trend. This neighbourhood definition has a major effect on the computational accuracy of the segmentation attributes. In order to efficiently cluster planar surfaces and prevent introducing ambiguities, the coordinates of the origin's projection on each point's best fitted plane are used as the clustering attributes. Then, an octree space partitioning method is utilized to detect and extract peaks from the attribute space. Each detected peak represents a specific cluster of points which are located on a distinct planar surface in the object space. Experimental results show the potential and feasibility of applying this method for segmentation of both airborne and terrestrial laser data.

One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres with enhanced photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Qu, Lingling [School of Chemistry and Chemical Engineering, Jiangsu University, Zhenjiang 212013 (China); Luo, Zhijun, E-mail: lzj@ujs.edu.cn [School of the Environment, Jiangsu University, Zhenjiang 212013 (China); State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093 (China); Tang, Chao [Maple Leaf International High School, Zhenjiang 212013 (China)

2013-11-15

Graphical abstract: Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core–shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs). Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation. - Highlights: • One step synthesis of Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon spheres. • Functional groups of sodium gluconate play synergetic roles in the formation of Bi@Bi{sub 2}O{sub 3}@CRCSs. • Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits enhanced photocatalytic activity under visible light irradiation. - Abstract: Bi@Bi{sub 2}O{sub 3}@carboxylate-rich carbon core-shell nanosturctures (Bi@Bi{sub 2}O{sub 3}@CRCSs) have been synthesized via a one-step method. The core–shell nanosturctures of the as-prepared samples were confirmed by X-ray powder diffraction (XRD), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), and Raman spectroscopy. The formation of Bi@Bi{sub 2}O{sub 3}@CRCSs core–shell nanosturctures should attribute to the synergetic roles of different functional groups of sodium gluconate. Bi@Bi{sub 2}O{sub 3}@CRCSs exhibits significant enhanced photocatalytic activity under visible light irradiation (λ > 420 nm) and shows an O{sub 2}-dependent feature. According to trapping experiments of radicals and holes, hydroxyl radicals were not the main active oxidative species in the photocatalytic degradation of MB, but O{sub 2}·{sup −} are the main active oxidative species.

Coralline algae are global palaeothermometers with bi-weekly resolution

Science.gov (United States)

Kamenos, N. A.; Cusack, M.; Moore, P. G.

2008-02-01

High resolution palaeoclimate data are required for the Holocene to resolve differences recorded by current proxies. The pole to pole distribution of rhodoliths (coralline algae) with their annual and sub-annual calcite bands make these attractive candidates for such a role. These bands contain climate information in the form of elemental traces. In situ temperature (IST) was recorded at two rhodolith beds for 1.5 years. The concentrations of MgCO 3 and SrCO 3 (mol %) deposited in Lithothamion glaciale and Phymatolithon calcareum over this 18- month period were determined using electron and ion microprobes. Highly significant linear relationships exist between Mg, Sr and IST as well as sea surface temperature. Calibration between Mg concentration and IST was used to obtain a 2-year temperature profile from a subfossil rhodolith thallus indicating half the seasonal peak-to-peak temperature amplitude earlier during the Holocene than the present day. Both slow-growing species (<200 μm year -1) allowed sampling resolutions of 23 year -1 which is equivalent to 1 reading every 2 weeks. Sub-monthly Mg and Sr records in rhodoliths make them unique globally distributed palaeothermometers which may help refine regional climate histories during the Holocene.

Evolution of orbital angular momentum entangled bi-photon, propagating through a turbulent atmosphere

CSIR Research Space (South Africa)

Roux, FS

2011-01-01

Full Text Available Orbital angular momentum (OAM) entangled bi-photons are a resource for the higher dimensional implementation of quantum cryptography, which allows secure communication over various channels. In the case where free-space is used as communication...

Effect of Prolonged Exposure Therapy Delivered Over 2 Weeks vs 8 Weeks vs Present-Centered Therapy on PTSD Symptom Severity in Military Personnel: A Randomized Clinical Trial.

Science.gov (United States)

Foa, Edna B; McLean, Carmen P; Zang, Yinyin; Rosenfield, David; Yadin, Elna; Yarvis, Jeffrey S; Mintz, Jim; Young-McCaughan, Stacey; Borah, Elisa V; Dondanville, Katherine A; Fina, Brooke A; Hall-Clark, Brittany N; Lichner, Tracey; Litz, Brett T; Roache, John; Wright, Edward C; Peterson, Alan L

2018-01-23

Effective and efficient treatment is needed for posttraumatic stress disorder (PTSD) in active duty military personnel. To examine the effects of massed prolonged exposure therapy (massed therapy), spaced prolonged exposure therapy (spaced therapy), present-centered therapy (PCT), and a minimal-contact control (MCC) on PTSD severity. Randomized clinical trial conducted at Fort Hood, Texas, from January 2011 through July 2016 and enrolling 370 military personnel with PTSD who had returned from Iraq, Afghanistan, or both. Final follow-up was July 11, 2016. Prolonged exposure therapy, cognitive behavioral therapy involving exposure to trauma memories/reminders, administered as massed therapy (n = 110; 10 sessions over 2 weeks) or spaced therapy (n = 109; 10 sessions over 8 weeks); PCT, a non-trauma-focused therapy involving identifying/discussing daily stressors (n = 107; 10 sessions over 8 weeks); or MCC, telephone calls from therapists (n = 40; once weekly for 4 weeks). Outcomes were assessed before and after treatment and at 2-week, 12-week, and 6-month follow-up. Primary outcome was interviewer-assessed PTSD symptom severity, measured by the PTSD Symptom Scale-Interview (PSS-I; range, 0-51; higher scores indicate greater PTSD severity; MCID, 3.18), used to assess efficacy of massed therapy at 2 weeks posttreatment vs MCC at week 4; noninferiority of massed therapy vs spaced therapy at 2 weeks and 12 weeks posttreatment (noninferiority margin, 50% [2.3 points on PSS-I, with 1-sided α = .05]); and efficacy of spaced therapy vs PCT at posttreatment. Among 370 randomized participants, data were analyzed for 366 (mean age, 32.7 [SD, 7.3] years; 44 women [12.0%]; mean baseline PSS-I score, 25.49 [6.36]), and 216 (59.0%) completed the study. At 2 weeks posttreatment, mean PSS-I score was 17.62 (mean decrease from baseline, 7.13) for massed therapy and 21.41 (mean decrease, 3.43) for MCC (difference in decrease, 3.70 [95% CI,0.72 to 6.68]; P = .02

Topotactic synthesis of a new BiS2-based superconductor Bi2(O,F)S2

Science.gov (United States)

Okada, Tomoyuki; Ogino, Hiraku; Shimoyama, Jun-ichi; Kishio, Kohji

2015-02-01

A new BiS2-based superconductor, Bi2(O,F)S2, was discovered. It is a layered compound consisting of alternately stacked structure of rock-salt-type BiS2 superconducting layers and fluorite-type Bi(O,F) blocking layers. Bi2(O,F)S2 was obtained as the main phase by topotactic fluorination of undoped Bi2OS2 using XeF2. This is the first topotactic synthesis of an electron-doped superconductor via reductive fluorination. With increasing F-content, a- and c-axis lengths increased and decreased, respectively, and Tc increased to 5.1 K.

Phonon and magnon scattering of Bi{sub 2}Fe{sub 4}O{sub 9} ceramic

Energy Technology Data Exchange (ETDEWEB)

Sharma, Poorva, E-mail: vdinesh33@rediffmail.com, E-mail: vdinesh33@rediffmail.com; Kumar, Ashwini, E-mail: vdinesh33@rediffmail.com, E-mail: vdinesh33@rediffmail.com; Varshney, Dinesh, E-mail: vdinesh33@rediffmail.com, E-mail: vdinesh33@rediffmail.com [School of Physics, Vigyan Bhawan, Devi Ahilya University, Khandwa Road Campus, Indore-452001 (India)

2014-04-24

We report the phonon structure of Bi{sub 2}Fe{sub 4}O{sub 9} ceramics as synthesized by solid-state reaction route. Rietveld refined X-ray diffraction patterns confirmed the formation of single-phase perovskite structure and all the peaks of Bi{sub 2}Fe{sub 4}O{sub 9} perfectly indexed to the orthorhombic (space group Pbam). Raman scattering measurements identifies 12A{sub g}+1B{sub 2g}+1B{sub 3g} Raman active optical phonon modes. Apart from phonon scattering, mode at 470 cm{sup −1} is observed which is due to magnon scattering. The P-E loop infers paraelectric nature of Bi{sub 2}Fe{sub 4}O{sub 9}.

Effect of the average soft-segment length on the morphology and properties of segmented polyurethane nanocomposites

International Nuclear Information System (INIS)

Finnigan, Bradley; Halley, Peter; Jack, Kevin; McDowell, Alasdair; Truss, Rowan; Casey, Phil; Knott, Robert; Martin, Darren

2006-01-01

Two organically modified layered silicates (with small and large diameters) were incorporated into three segmented polyurethanes with various degrees of microphase separation. Microphase separation increased with the molecular weight of the poly(hexamethylene oxide) soft segment. The molecular weight of the soft segment did not influence the amount of polyurethane intercalating the interlayer spacing. Small-angle neutron scattering and differential scanning calorimetry data indicated that the layered silicates did not affect the microphase morphology of any host polymer, regardless of the particle diameter. The stiffness enhancement on filler addition increased as the microphase separation of the polyurethane decreased, presumably because a greater number of urethane linkages were available to interact with the filler. For comparison, the small nanofiller was introduced into a polyurethane with a poly(tetramethylene oxide) soft segment, and a significant increase in the tensile strength and a sharper upturn in the stress-strain curve resulted. No such improvement occurred in the host polymers with poly(hexamethylene oxide) soft segments. It is proposed that the nanocomposite containing the more hydrophilic and mobile poly(tetramethylene oxide) soft segment is capable of greater secondary bonding between the polyurethane chains and the organosilicate surface, resulting in improved stress transfer to the filler and reduced molecular slippage.

Sodium citrate-assisted anion exchange strategy for construction of Bi2O2CO3/BiOI photocatalysts

International Nuclear Information System (INIS)

Song, Peng-Yuan; Xu, Ming; Zhang, Wei-De

2015-01-01

Highlights: • Heterostructured Bi 2 O 2 CO 3 /BiOI microspheres were prepared via anion exchange. • Sodium citrate-assisted anion exchange for construction of composite photocatalysts. • Bi 2 O 2 CO 3 /BiOI composites show high visible light photocatalytic activity. - Abstract: Bi 2 O 2 CO 3 /BiOI heterojuncted photocatalysts were constructed through a facile partial anion exchange strategy starting from BiOI microspheres and urea with the assistance of sodium citrate. The content of Bi 2 O 2 CO 3 in the catalysts was regulated by modulating the amount of urea as a precursor, which was decomposed to generate CO 3 2− in the hydrothermal process. Citrate anion plays a key role in controlling the morphology and composition of the products. The Bi 2 O 2 CO 3 /BiOI catalysts display much higher photocatalytic activity than pure BiOI and Bi 2 O 2 CO 3 towards the degradation of rhodamine B (RhB) and bisphenol A (BPA). The enhancement of photocatalytic activity of the heterojuncted catalysts is attributed to the formation of p–n junction between p-BiOI and n-Bi 2 O 2 CO 3 , which is favorable for retarding the recombination of photoinduced electron-hole pairs. Moreover, the holes are demonstrated to be the main active species for the degradation of RhB and BPA

Targeted ultraviolet B phototherapy in vitiligo: A comparison between once-weekly and twice-weekly treatment regimens

Directory of Open Access Journals (Sweden)

Imran Majid

2015-01-01

Full Text Available Background: Targeted ultraviolet B (T-UVB phototherapy in vitiligo is usually administered twice or thrice a week on non-consecutive days. It is difficult for many patients to adhere to this regimen, forcing them to discontinue treatment. Aim: The study aimed to compare the efficacy of twice-weekly and once-weekly targeted ultraviolet B phototherapy regimens in vitiligo. Methods: Sixty patients with non-segmental vitiligo on the face, neck or trunk were divided into two groups of 30 patients each. The patients in group A received targeted ultraviolet B twice weekly, while those in group B received targeted ultraviolet B once weekly. Repigmentation was monitored and graded as excellent (≥75% repigmentation, good (50−74% repigmentation and poor (<50% repigmentation. The extent of repigmentation at each body site (primary outcome measure, the number of doses required for initiation of pigmentation, and the cumulative dose of targeted ultraviolet B administered was calculated and compared between both groups. Results: A total of 90 lesions (48 in the twice weeklygroup and 42 in the once weekly group were treated on the face, neck and trunk. Excellent results were obtained in 62.5% (30/48 of lesions treated twice weekly, and 64.3% (27/42 in lesions treated once weekly. The mean number of doses required for initiation of pigmentation was 4.69 in the twice weekly group, and 4.35 in the once weekly group. The patients in the twice weekly group received a mean cumulative dose of 8.26 J/cm 2, while the once weekly group received 7.69 J/cm 2. No statistically significant differences were observed between the two groups with respect to the outcome, with respect to the total repigmentation, the number of doses till onset of pigmentation, as well as the cumulative dose of targeted UVB. Conclusion: Once-weekly targeted ultraviolet B phototherapy appears to be as efficacious as the twice-weekly regimen in vitiligo.

Legal and Political Implications of Offensive Actions from and Against the Space Segment

Science.gov (United States)

de Angelis, Iole M.

2002-01-01

deployment of strategic weapons, kinetic energy weapons and directed energy weapons are already contained within existing rules and such issues are being actively addressed by the international community. At the same time, the use of cyberwar and electronic warfare to counter space technology not only encounters a void of international rules, but it is a question that is very rarely taken into consideration while addressing to the issues of preventing space warfare. Finally, these techniques are easily available to non-state organisations - terrorist organisations and commercial companies - and individuals. In conclusion, the issues related to offensive actions towards and from space shall be taken into consideration not only in a military perspective, but also in a political perspective - terrorist actions against the space segment - and from an economical point of view.

Epo’s Chronicles: A Weekly Webcomic That Teaches Space Science

Science.gov (United States)

Prasad, K.; Simonnet, A.; John, K.; Hill, L.; McLin, K.; Cominsky, L.

2009-12-01

Sonoma State University Education and Public Outreach presents Epo’s Chronicles: a weekly web comic about Epo, a sentient spaceship/observatory and its humanoid companion, Alkina. Excite your students by reading the weekly adventures of Epo and Alkina as they explore the Universe and try to discover their origins. The comic employs a fictional story line incorporating both recent and classic scientific discoveries from NASA missions while increasing interest in science in a creative and engaging way. Each weekly “eposode” is translated into French, Italian and Spanish, and is accompanied by supporting information including glossary entries, multi-media clips, and links to additional resources.

Improving image segmentation by learning region affinities

Energy Technology Data Exchange (ETDEWEB)

Prasad, Lakshman [Los Alamos National Laboratory; Yang, Xingwei [TEMPLE UNIV.; Latecki, Longin J [TEMPLE UNIV.

2010-11-03

We utilize the context information of other regions in hierarchical image segmentation to learn new regions affinities. It is well known that a single choice of quantization of an image space is highly unlikely to be a common optimal quantization level for all categories. Each level of quantization has its own benefits. Therefore, we utilize the hierarchical information among different quantizations as well as spatial proximity of their regions. The proposed affinity learning takes into account higher order relations among image regions, both local and long range relations, making it robust to instabilities and errors of the original, pairwise region affinities. Once the learnt affinities are obtained, we use a standard image segmentation algorithm to get the final segmentation. Moreover, the learnt affinities can be naturally unutilized in interactive segmentation. Experimental results on Berkeley Segmentation Dataset and MSRC Object Recognition Dataset are comparable and in some aspects better than the state-of-art methods.

Ternary rare-earth bismuthides RE5SiBi 2 and RE5GeBi 2 ( RE=La-Nd, Gd-Er): Stabilization of the β-Yb 5Sb 3-type structure through tetrel substitution

Science.gov (United States)

Barry, Stephen D.; Tkachuk, Andriy V.; Bie, Haiying; Blanchard, Peter E. R.; Mar, Arthur

2011-01-01

Ternary bismuthides RE5TtBi 2 containing rare-earth ( RE=La-Nd, Gd-Er) and tetrel ( Tt=Si, Ge) atoms have been prepared by arc-melting of the elements followed by annealing at 800 °C. They adopt the β-Yb 5Sb 3-type structure (Pearson symbol o P32, space group Pnma, Z=4), as revealed through analysis by single-crystal X-ray diffraction on Ce 5Si 0.869(4)Bi 2.131(4) and powder X-ray diffraction on Ce 5GeBi 2. Cell parameters for the entire series lie in the ranges of a=12.8-11.8 Å, b=9.6-9.0 Å, and c=8.4-7.9 Å. Solid solubility in Ce 5Si xBi 3- x and Pr 5Si xBi 3- x (approximately 0.9≤ x≤1.2, depending on the RE member) is much more limited compared to the antimonides, consistent with a highly ordered structure in which the two possible anion sites are essentially segregated into a smaller one occupied by Tt atoms (CN7) and a larger one occupied by Bi atoms (CN9). Band structure calculations on La 5SiBi 2 confirm the importance of La-La bonding interactions near the Fermi level. X-ray photoelectron spectra support the presence of partially anionic Bi atoms, as indicated by a small negative binding energy shift relative to elemental Bi. The Ce and Pr members undergo magnetic transitions at low temperatures, possibly involving ferromagnetic interactions, that are strongly influenced by the nature of the Tt atom.

Optimization of excess Bi doping to enhance ferroic orders of spin casted BiFeO{sub 3} thin film

Energy Technology Data Exchange (ETDEWEB)

Gupta, Surbhi; Gupta, Vinay, E-mail: drguptavinay@gmail.com [Department of Physics and Astrophysics, University of Delhi, Delhi (India); Tomar, Monika [Department of Physics, Miranda Housea, University of Delhi, Delhi (India); James, A. R. [Defence Metallurgical Research Laboratory, Hyderabad (India); Pal, Madhuparna; Guo, Ruyan; Bhalla, Amar [Department of Electrical and Computer Engineering, College of Engineering, University of Texas at SanAntonio, San Antonio 78249 (United States)

2014-06-21

Multiferroic Bismuth Ferrite (BiFeO{sub 3}) thin films with varying excess bismuth (Bi) concentration were grown by chemical solution deposition technique. Room temperature multiferroic properties (ferromagnetism, ferroelectricity, and piezoelectricity) of the deposited BiFeO{sub 3} thin films have been studied. High resolution X-ray diffraction and Raman spectroscopy studies reveal that the dominant phases formed in the prepared samples change continuously from a mixture of BiFeO{sub 3} and Fe{sub 2}O{sub 3} to pure BiFeO{sub 3} phase and, subsequently, to a mixture of BiFeO{sub 3} and Bi{sub 2}O{sub 3} with increase in the concentration of excess Bi from 0% to 15%. BiFeO{sub 3} thin films having low content (0% and 2%) of excess Bi showed the traces of ferromagnetic phase (γ-Fe{sub 2}O{sub 3}). Deterioration in ferroic properties of BiFeO{sub 3} thin films is also observed when prepared with higher content (15%) of excess Bi. Single-phased BiFeO{sub 3} thin film prepared with 5% excess Bi concentration exhibited the soft ferromagnetic hysteresis loops and ferroelectric characteristics with remnant polarization 4.2 μC/cm{sup 2} and saturation magnetization 11.66 emu/g. The switching of fine spontaneous domains with applied dc bias has been observed using piezoresponse force microscopy in BiFeO{sub 3} thin films having 5% excess Bi. The results are important to identify optimum excess Bi concentration needed for the formation of single phase BiFeO{sub 3} thin films exhibiting the improved multiferroic properties.

Investigation of the electronic structure of the BiSBr and BiSeBr clusters by density functional method

International Nuclear Information System (INIS)

Audzijonis, A.; Gaigalas, G.; Zigas, L.; Pauliukas, A.; Zaltauskas, R.; Kvedaravicius, A.; Cerskus, A.

2008-01-01

The energy levels of valence bands (VB) of the BiSBr and BiSeBr crystals have been calculated for investigation of the photoelectron emission spectra of BiSBr, BiSeBr and BiSI crystals. The molecular model of this crystal has been used for the calculation of VB by the Density Functional Theory (DFT) method. The molecular cluster, consisting of 20 molecules of BiSBr, BiSeBr, has been used for calculations of averaged total density of states, including atom vibrations. The spectra of the averaged total density of states from VB of BiSBr and BiSeBr clusters have been compared with the experimental photoelectron emission spectra from VB of BiSI crystals. The results clarify that the atomic vibrations in A 5 B 6 C 7 type crystals with chain structure create a smoother appearance of the averaged total density of state spectrum and the experimental X-ray photoemission spectra (XPS)

Influence of Fe substitution on structural and magnetic features of BiMn2O5 nanostructures

Science.gov (United States)

Gaikwad, Vishwajit M.; Goyal, Saveena; Yanda, Premakumar; Sundaresan, A.; Chakraverty, Suvankar; Ganguli, Ashok K.

2018-04-01

Nanostructures of complex oxides [BiFexMn2-xO5 (x = 0, 1, 2)] have been designed to study their structural, optical and magnetic behaviour. X-ray diffraction data (XRD) revealed orthorhombic phase with Pbam space group. Noticeable expansion in unit cell parameters has been found from BiMn2O5 (x = 0) to BiFe2O4.5 (x = 2). The observed structural changes via tuning of B-site (x = 0-2) played an important role in overall magnetic properties. Transmission electron microscopic images confirm that the average particle size of all the materials are in nano domain range with different morphologies. From optical studies, it has been found that the observed energy band gap values are strongly related to 3d electron numbers. These values appear to be larger than that reported for bulk. Isothermal magnetization plots (at 5 K) show increase in coercivity (Hc) from x = 0 to x = 2. Temperature dependent magnetization studies implied anti-ferromagnetic interactions for BiMn2O5, frustrated magnet for BiFeMnO5 and ferromagnetic behaviour for BiFe2O4.5. Ferromagnetic state of nanostructured BiFe2O4.5 is in contrast with its bulk counterparts.

Luminescence of Bi3+ ions in Y3Al5O12:Bi single crystalline films

International Nuclear Information System (INIS)

Zorenko, Yu.; Gorbenko, V.; Voznyak, T.; Vistovsky, V.; Nedilko, S.; Nikl, M.

2007-01-01

The absorption and cathodoluminescence spectra of single crystalline films (SCF) of Y 3 Al 5 O 12 :Bi garnet depending on Bi concentration were analyzed. For consideration of the nature of the UV and visible Bi-related emission bands the time-resolved luminescence of Bi 3+ (ns 2 ) ions in YAG:Bi SCF was studied at 10 K under excitation by synchrotron radiation. The difference in the excitation spectra and emission decay of the UV and visible bands has been explained via radiative relaxation from the 3 P 1,0 excited states to the 1 S 0 ground state of the isolated and pair/clustered Bi 3+ emission centers in the garnet lattice, respectively

Thermoelectric properties and thermal stability of Bi-doped PbTe single crystal

Science.gov (United States)

Chen, Zhong; Li, Decong; Deng, Shuping; Tang, Yu; Sun, Luqi; Liu, Wenting; Shen, Lanxian; Yang, Peizhi; Deng, Shukang

2018-06-01

In this study, n-type Bi-doped single-crystal PbTe thermoelectric materials were prepared by melting and slow cooling method according to the stoichiometric ratio of Pb:Bi:Te = 1-x:x:1 (x = 0, 0.1, 0.15, 0.2, 0.25). The X-ray diffraction patterns of Pb1-xBixTe samples show that all main diffraction peaks are well matched with the PbTe matrix, which has a face-centered cubic structure with the space group Fm 3 bar m . Electron probe microanalysis reveals that Pb content decreases gradually, and Te content remains invariant basically with the increase of Bi content, indicating that Bi atoms are more likely to replace Pb atoms. Thermal analysis shows that the prepared samples possess relatively high thermal stability. Simultaneously, transmission electron microscopy and selected area electron diffraction pattern indicate that the prepared samples have typical single-crystal structures with good mechanical properties. Moreover, the electrical conductivity of the prepared samples improved significantly compared with that of the pure sample, and the maximum ZT value of 0.84 was obtained at 600 K by the sample with x = 0.2.

Just one week 'til GridWorld

CERN Multimedia

Harris, Derrick

2006-01-01

"Here we are, one week from GridWorld, and I can feel the pressure rising. Although the news has been a little slow recently, I know that won't last long, and between next week and mid-November, I have a feelling I'll have heard from just about every vendor and organization in the Grid space." (1 page)

Photoreduction of non-noble metal Bi on the surface of Bi{sub 2}WO{sub 6} for enhanced visible light photocatalysis

Energy Technology Data Exchange (ETDEWEB)

Zhang, Xiaojing [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); Yu, Shan; Liu, Yang; Zhang, Qian [The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); Zhou, Ying, E-mail: yzhou@swpu.edu.cn [State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China); The Center of New Energy Materials and Technology, School of Materials Science and Engineering, Southwest Petroleum University, No. 8, Xindu Road, Xindu District, Chengdu 610500 (China)

2017-02-28

Highlights: • Bi{sub 2}WO{sub 6}-Bi composite was synthesized by in situ photoreduction of Bi{sub 2}WO{sub 6}. • Bi{sub 2}WO{sub 6}-Bi exhibits improved photocatalytic efficiency towards degradation of Rhodamine B. • The generation of elemental Bi in Bi{sub 2}WO{sub 6}-Bi induces vacancy and structure distortion of Bi{sub 2}WO{sub 6}. • The surface oxygen adsorption mode changes from hydroxyl group on Bi{sub 2}WO{sub 6} to molecular oxygen on Bi{sub 2}WO{sub 6}-Bi. - Abstract: In this report, Bi{sub 2}WO{sub 6}-Bi composite was prepared through an in situ photoreduction method and was characterized systematically by X-Ray diffraction, transmission electron microscopy, X-Ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The as-prepared Bi{sub 2}WO{sub 6}-Bi maintains the same crystal structure with the pristine Bi{sub 2}WO{sub 6} regardless of some surface defects. Nevertheless, these surface defects result in the change of surface oxygen adsorption mode from hydroxyl to molecular oxygen on Bi{sub 2}WO{sub 6}. Photocatalytic activity over Bi{sub 2}WO{sub 6}-Bi is 2.4 times higher than that of Bi{sub 2}WO{sub 6} towards the degradation of organic dye Rhodamine B (RhB) under visible light irradiation (λ > 420 nm). A deep study shows that cleavage of benzene ring is the main pathway for RhB degradation over Bi{sub 2}WO{sub 6}, but both the benzene cleavage and de-ethylation pathway coexist for RhB decomposition in the presence of Bi{sub 2}WO{sub 6}-Bi as the photocatalyst. Photoelectrochemical study including transient photocurrent tests and electrochemical impedance spectroscopy measurements shows that Bi{sub 2}WO{sub 6}-Bi could facilitate the charge transfer process compared to Bi{sub 2}WO{sub 6}. These data above has indicated a new insight into the promotion mechanism based on Bi related heterostructures.

Reduction of Gas Bubbles and Improved Critical Current Density in Bi-2212 Round Wire by Swaging

CERN Document Server

Jiang, J; Huang, Y; Hong, S; Parrell, J; Scheuerlein, C; Di Michiel, M; Ghosh, A; Trociewitz, U; Hellstrom, E; Larbalestier, D

2013-01-01

Bi-2212 round wire is made by the powder-in-tube technique. An unavoidable property of powder-in-tube conductors is that there is about 30% void space in the as-drawn wire. We have recently shown that the gas present in the as-drawn Bi-2212 wire agglomerates into large bubbles and that they are presently the most deleterious current limiting mechanism. By densifying short 2212 wires before reaction through cold isostatic pressing (CIPping), the void space was almost removed and the gas bubble density was reduced significantly, resulting in a doubled engineering critical current density (JE) of 810 A/mm2 at 5 T, 4.2 K. Here we report on densifying Bi-2212 wire by swaging, which increased JE (4.2 K, 5 T) from 486 A/mm2 for as-drawn wire to 808 A/mm2 for swaged wire. This result further confirms that enhancing the filament packing density is of great importance for making major JE improvement in this round-wire magnet conductor.

Total dose hardness of a commercial SiGe BiCMOS technology

International Nuclear Information System (INIS)

Van Vonno, N.; Lucas, R.; Thornberry, D.

1999-01-01

Over the past decade SiGe HBT technology has progress from the laboratory to actual commercial applications. When integrated into a BiMOS process, this technology has applications in low-cost space systems. In this paper, we report results of total dose testing of a SiGe/CMOS process accessible through a commercial foundry. (authors)

Five-Segment Solid Rocket Motor Development Status

Science.gov (United States)

Priskos, Alex S.

2012-01-01

In support of the National Aeronautics and Space Administration (NASA), Marshall Space Flight Center (MSFC) is developing a new, more powerful solid rocket motor for space launch applications. To minimize technical risks and development costs, NASA chose to use the Space Shuttle s solid rocket boosters as a starting point in the design and development. The new, five segment motor provides a greater total impulse with improved, more environmentally friendly materials. To meet the mass and trajectory requirements, the motor incorporates substantial design and system upgrades, including new propellant grain geometry with an additional segment, new internal insulation system, and a state-of-the art avionics system. Significant progress has been made in the design, development and testing of the propulsion, and avionics systems. To date, three development motors (one each in 2009, 2010, and 2011) have been successfully static tested by NASA and ATK s Launch Systems Group in Promontory, UT. These development motor tests have validated much of the engineering with substantial data collected, analyzed, and utilized to improve the design. This paper provides an overview of the development progress on the first stage propulsion system.

Ion-temperature-gradient-driven modes in bi-ion magnetoplasma

Energy Technology Data Exchange (ETDEWEB)

Batool, Nazia; Mirza, Arshad M [Theoretical Plasma Physics Group, Department of Physics, Quaid-i-Azam University, Islamabad 45320 (Pakistan); Qamar, Anisa [Department of Physics, Peshawar University, NWFP 25120 (Pakistan)], E-mail: nazia.batool@ncp.edu.pk

2008-12-15

The toroidal ion-temperature-gradient (ITG)-driven electrostatic drift waves are investigated for bi-ion plasmas with equilibrium density, temperature and magnetic field gradients. Using Braginskii's transport equations for the ions and Boltzmann distributed electrons, the mode coupling equations are derived. New ITG-driven modes are shown to exist. The results of the present study should be helpful to understand several wave phenomena in space and tokamak plasmas.

Epo's Chronicles: A Weekly Webcomic That Teaches Space Science

Science.gov (United States)

Cominsky, Lynn R.; Prasad, K.; Simonnet, A.; John, K.; McLin, K.; Hill, L.

2009-01-01

Sonoma State University Education and Public Outreach presents Epo's Chronicles: a weekly web comic about Epo, a sentient spaceship/observatory and its humanoid companion, Alkina. Follow the adventures of Epo and Alkina as they explore the Universe and try to discover their origins. The comic employs a fictional story line incorporating both recent and classic scientific discoveries from NASA missions while educating the young and the young at heart in a creative and engaging way. Each weekly "eposode” is translated into French, Italian and Spanish, and is accompanied by supporting information including glossary entries, multi-media clips, and links to additional resources. Visit Epo's Chronicles at: http://eposchronicles.com

Trajectory Based Optimal Segment Computation in Road Network Databases

DEFF Research Database (Denmark)

Li, Xiaohui; Ceikute, Vaida; Jensen, Christian S.

2013-01-01

Finding a location for a new facility such that the facility attracts the maximal number of customers is a challenging problem. Existing studies either model customers as static sites and thus do not consider customer movement, or they focus on theoretical aspects and do not provide solutions...... that are shown empirically to be scalable. Given a road network, a set of existing facilities, and a collection of customer route traversals, an optimal segment query returns the optimal road network segment(s) for a new facility. We propose a practical framework for computing this query, where each route...... traversal is assigned a score that is distributed among the road segments covered by the route according to a score distribution model. The query returns the road segment(s) with the highest score. To achieve low latency, it is essential to prune the very large search space. We propose two algorithms...

Trajectory Based Optimal Segment Computation in Road Network Databases

DEFF Research Database (Denmark)

Li, Xiaohui; Ceikute, Vaida; Jensen, Christian S.

Finding a location for a new facility such that the facility attracts the maximal number of customers is a challenging problem. Existing studies either model customers as static sites and thus do not consider customer movement, or they focus on theoretical aspects and do not provide solutions...... that are shown empirically to be scalable. Given a road network, a set of existing facilities, and a collection of customer route traversals, an optimal segment query returns the optimal road network segment(s) for a new facility. We propose a practical framework for computing this query, where each route...... traversal is assigned a score that is distributed among the road segments covered by the route according to a score distribution model. The query returns the road segment(s) with the highest score. To achieve low latency, it is essential to prune the very large search space. We propose two algorithms...

DFT study on the interfacial properties of vertical and in-plane BiOI/BiOIO3 hetero-structures.

Science.gov (United States)

Dai, Wen-Wu; Zhao, Zong-Yan

2017-04-12

Composite photocatalysts with hetero-structures usually favor the effective separation of photo-generated carriers. In this study, BiOIO 3 was chosen to form a hetero-structure with BiOI, due to its internal polar field and good lattice matching with BiOI. The interfacial properties and band offsets were focused on and analyzed in detail by DFT calculations. The results show that the charge depletion and accumulation mainly occur in the region near the interface. This effect leads to an interfacial electric field and thus, the photo-generated electron-hole pairs can be easily separated and transferred along opposite directions at the interface, which is significant for the enhancement of the photocatalytic activity. Moreover, according to the analysis of band offsets, the vertical BiOI/BiOIO 3 belongs to the type-II hetero-structure, while the in-plane BiOI/BiOIO 3 belongs to the type-I hetero-structure. The former type of hetero-structure has more favorable effects to enhance the photocatalytic activity of BiOI than that of the latter type of hetero-structure. In the case of the vertical BiOI/BiOIO 3 hetero-structure, photo-generated electrons can move from the conduction band of BiOI to that of BiOIO 3 , while holes can move from the valence band of BiOIO 3 to that of BiOI under solar radiation. In addition, the introduced internal electric field functions as a selector that can promote the separation of photo-generated carriers, resulting in the higher photocatalytic quantum efficiency. These findings illustrate the underlying mechanism for the reported experiments, and can be used as a basis for the design of novel highly efficient composite photocatalysts with hetero-structures.

Strongly compressed Bi (111) bilayer films on Bi{sub 2}Se{sub 3} studied by scanning tunneling microscopy

Energy Technology Data Exchange (ETDEWEB)

Zhang, K. F.; Yang, Fang; Song, Y. R. [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Liu, Canhua; Qian, Dong; Gao, C. L.; Jia, Jin-Feng [Key Laboratory of Artificial Structures and Quantum Control (Ministry of Education), Department of Physics and Astronomy, Shanghai Jiao Tong University, Shanghai 200240 (China); Collaborative Innovation Center of Advanced Microstructures, Nanjing 210093 (China)

2015-09-21

Ultra-thin Bi films show exotic electronic structure and novel quantum effects, especially the widely studied Bi (111) film. Using reflection high-energy electron diffraction and scanning tunneling microscopy, we studied the structure and morphology evolution of Bi (111) thin films grown on Bi{sub 2}Se{sub 3}. A strongly compressed, but quickly released in-plane lattice of Bi (111) is found in the first three bilayers. The first bilayer of Bi shows a fractal growth mode with flat surface, while the second and third bilayer show a periodic buckling due to the strong compression of the in-plane lattice. The lattice slowly changes to its bulk value with further deposition of Bi.

Frictionless segmented mechanics for controlled space closure

OpenAIRE

Andrade Jr, Ildeu

2017-01-01

ABSTRACT Extraction spaces may be needed to achieve specific orthodontic goals of positioning the dentition in harmony with the craniofacial complex. However, the fundamental reality that determines the occlusion final position is the control exerted by the orthodontist while closing the extraction spaces. A specific treatment objective may require the posterior teeth to remain in a constant position anteroposteriorly as well as vertically, while the anterior teeth occupy the entire extractio...

Retinal Vessel Segmentation via Structure Tensor Coloring and Anisotropy Enhancement

Directory of Open Access Journals (Sweden)

Mehmet Nergiz

2017-11-01

Full Text Available Retinal vessel segmentation is one of the preliminary tasks for developing diagnosis software systems related to various retinal diseases. In this study, a fully automated vessel segmentation system is proposed. Firstly, the vessels are enhanced using a Frangi Filter. Afterwards, Structure Tensor is applied to the response of the Frangi Filter and a 4-D tensor field is obtained. After decomposing the Eigenvalues of the tensor field, the anisotropy between the principal Eigenvalues are enhanced exponentially. Furthermore, this 4-D tensor field is converted to the 3-D space which is composed of energy, anisotropy and orientation and then a Contrast Limited Adaptive Histogram Equalization algorithm is applied to the energy space. Later, the obtained energy space is multiplied by the enhanced mean surface curvature of itself and the modified 3-D space is converted back to the 4-D tensor field. Lastly, the vessel segmentation is performed by using Otsu algorithm and tensor coloring method which is inspired by the ellipsoid tensor visualization technique. Finally, some post-processing techniques are applied to the segmentation result. In this study, the proposed method achieved mean sensitivity of 0.8123, 0.8126, 0.7246 and mean specificity of 0.9342, 0.9442, 0.9453 as well as mean accuracy of 0.9183, 0.9442, 0.9236 for DRIVE, STARE and CHASE_DB1 datasets, respectively. The mean execution time of this study is 6.104, 6.4525 and 18.8370 s for the aforementioned three datasets respectively.

Newly designed PdRuBi/N-Graphene catalysts with synergistic effects for enhanced ethylene glycol electro-oxidation

International Nuclear Information System (INIS)

Li, Tengfei; Huang, Yiyin; Ding, Kui; Wu, Peng; Abbas, Syed Comail; Ghausi, Muhammad Arsalan; Zhang, Teng; Wang, Yaobing

2016-01-01

Graphical abstract: We rationally design and synthesize a ternary PdRuBi/NG catalyst with significantly enhanced catalytic activity with synergetic effect of Ru and Bi towards ethylene glycol electro-oxidation. - Abstract: Palladium (Pd)-based catalysts are appealing electro-catalysts for alcohol oxidation reaction in fuel cell, but still not efficient as the complicated oxidation process and sluggish kinetic. Here we rationally design and synthesize a PdRuBi/NG tri-metallic catalyst with space synergetic effect for enhanced ethylene glycol electro-oxidation, in which both Ru and Bi in the catalyst are synergistic effective in promoting catalytic activity of Pd catalytic interlayer by electronic effect and surface modification mechanism respectively. It shows 4.2 times higher peak current density towards ethylene glycol electro-oxidation than commercial Pd/C catalyst, and the catalytic durability is also greatly improved.

An ion exchange strategy to BiOI/CH{sub 3}COO(BiO) heterojunction with enhanced visible-light photocatalytic activity

Energy Technology Data Exchange (ETDEWEB)

Han, Qiaofeng, E-mail: hanqiaofeng@njust.edu.cn; Yang, Zhen; Wang, Li; Shen, Zichen; Wang, Xin; Zhu, Junwu; Jiang, Xiaohong

2017-05-01

Highlights: • BiOI/BiOAc heterojunction was firstly synthesized by an ion exchange route. • BiOI/BiOAc exhibited enhanced visible-light-driven photoreactivity for the dyes degradation in comparison with individuals. • Photocatalytic activity of the as-prepared BiOI/BiOAc is better than that prepared by precipitation-deposition method. • Photosensitization effect of BiOI to BiOAc was superior to that of Bi{sub 2}S{sub 3} due to suitable solubility constant. - Abstract: It is very significant to develop CH{sub 3}COO(BiO) (denoted as BiOAc) based photocatalysts for the removal of pollutants due to its non-toxicity and availability. We previously reported that BiOAc exhibited excellent photocatalytic activity for rhodamine B (RhB) degradation under UV light irradiation. Herein, by an ion exchange approach, BiOI/BiOAc heterojunction could be easily obtained. The as-prepared heterojunction possessed enhanced photodegradation activity for multiple dyes including RhB and methyl orange (MO) under visible light illumination in comparison with individual materials. Good visible-light photocatalytic activity of the heterojunction could be attributed to the increased visible light response, effective charge transfer from the modified band position and close interfacial contact due to partial ion exchange method.

Synthesis of chemically bonded BiOCl@Bi{sub 2}WO{sub 6} microspheres with exposed (0 2 0) Bi{sub 2}WO{sub 6} facets and their enhanced photocatalytic activities under visible light irradiation

Energy Technology Data Exchange (ETDEWEB)

Ma, Yongchao [Qingdao Agricultural University, Qingdao 266109 (China); Chen, Zhiwei [School of Life Sciences, Shandong University of Technology, Zibo 255049 (China); Qu, Dan [Qingdao Agricultural University, Qingdao 266109 (China); Shi, Jinsheng, E-mail: jsshiqn@aliyun.com [Qingdao Agricultural University, Qingdao 266109 (China)

2016-01-15

Graphical abstract: - Highlights: • BiOCl@Bi{sub 2}WO{sub 6} composites were prepared via a controlled anion exchange method. • The shell of composites was composed of Bi{sub 2}WO{sub 6} sheets with exposed (0 2 0) facets. • The BiOCl@Bi{sub 2}WO{sub 6} composites showed efficient photocatalytic activity. • A possible photocatalytic degradation mechanism is proposed. - Abstract: Bi{sub 2}WO{sub 6} photocatalysts has been extensively studied for its photocatalytic activity. However, few works have been conducted on hierarchical Bi{sub 2}WO{sub 6} composite photocatalysts with specifically exposed facets. In this work, we report a facile method to synthesize BiOCl@Bi{sub 2}WO{sub 6} hierarchical composite microspheres. Bi{sub 2}WO{sub 6} nanosheets with specifically exposed (0 2 0) facet were directly formed on the surface of BiOCl precursor microspheres via a controlled anion exchange route between BiOCl and Na{sub 2}WO{sub 4}. The visible-light photocatalytic activity of the BiOCl@Bi{sub 2}WO{sub 6} heterojunction with exposed (0 2 0) facets (denoted as BiOCl@Bi{sub 2}WO{sub 6}) was investigated by degradation of Rhodamine B (RhB) and ciprofloxacin (CIP) aqueous solution under visible light irradiation. The experimental results indicated that the BiOCl@Bi{sub 2}WO{sub 6} composite microsphere with intimate interfacial contacts exhibited improved efficiency for RhB photodegradation in comparison with pure BiOCl and Bi{sub 2}WO{sub 6}. The BiOCl@Bi{sub 2}WO{sub 6} composite microsphere also shows high photocatalytic activity for degradation of CIP under visible light irradiation. The enhanced photocatalytic performance of BiOCl@Bi{sub 2}WO{sub 6}-020 hierarchical microspheres can be ascribed to the improved visible light harvesting ability, high charge separation and transfer. This work will make significant contributions toward the exploration of novel heterostructures with high potential in photocatalytic applications.

Local variation in Bi crystal sites of epitaxial GaAsBi studied by photoelectron spectroscopy and first-principles calculations

Energy Technology Data Exchange (ETDEWEB)

Laukkanen, P., E-mail: pekka.laukkanen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Punkkinen, M.P.J., E-mail: marko.punkkinen@utu.fi [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Lahti, A. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Puustinen, J. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Tuominen, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Hilska, J. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Mäkelä, J.; Dahl, J.; Yasir, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Kuzmin, M. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland); Ioffe Physical-Technical Institute, Russian Academy of Sciences, St. Petersburg 194021, Russian Federation (Russian Federation); Osiecki, J.R.; Schulte, K. [The MAX IV laboratory, P. O. Box 118, Lund University, SE-221 00 Lund (Sweden); Guina, M. [Optoelectronics Research Centre, Tampere University of Technology, FI-33101 Tampere (Finland); Kokko, K. [Department of Physics and Astronomy, University of Turku, FI-20014 Turku (Finland)

2017-02-28

Highlights: • XPS is used to study bulk-like properties of GaAsBi crystals. • Surface effects are removed from XPS signal by an epitaxial AlAs cap film. • Local variation of Bi composition is found. • The result is consistent with photoluminescence and theoretical results. • Ga vacancies and Bi crystallites are suggested to be dominating defects. - Abstract: Epitaxial Bi-containing III–V crystals (III-V{sub 1-x}Bi{sub x}) have attracted increasing interest due to their potential in infrared applications. Atomic-scale characterization and engineering of bulk-like III-V{sub 1-x}Bi{sub x} properties (e.g., Bi incorporation and defect formation) are challenging but relevant to develop applications. Toward that target, we report here that the traditional surface-science measurement of photoelectron spectroscopy (PES) is a potential, non-destructive method to be combined in the studies of bulk-like properties, when surface effects are properly removed. We have investigated epitaxial GaAs{sub 1-x}Bi{sub x} films, capped by epitaxial AlAs layers, with high-resolution photoelectron spectroscopy. The Bi5d core-level spectra of GaAs{sub 1-x}Bi{sub x} together with ab-initio calculations give direct evidence of variation of Bi bonding environment in the lattice sites. The result agrees with photoluminescence (PL) measurement which shows that the studied GaAs{sub 1-x}Bi{sub x} films include local areas with higher Bi content, which contribute to PL but do not readily appear in x-ray diffraction (XRD). The measured and calculated Bi core-level shifts show also that Ga vacancies and Bi clusters are dominant defects.

Multidimensional Brain MRI segmentation using graph cuts

International Nuclear Information System (INIS)

Lecoeur, Jeremy

2010-01-01

This thesis deals with the segmentation of multimodal brain MRIs by graph cuts method. First, we propose a method that utilizes three MRI modalities by merging them. The border information given by the spectral gradient is then challenged by a region information, given by the seeds selected by the user, using a graph cut algorithm. Then, we propose three enhancements of this method. The first consists in finding an optimal spectral space because the spectral gradient is based on natural images and then inadequate for multimodal medical images. This results in a learning based segmentation method. We then explore the automation of the graph cut method. Here, the various pieces of information usually given by the user are inferred from a robust expectation-maximization algorithm. We show the performance of these two enhanced versions on multiple sclerosis lesions. Finally, we integrate atlases for the automatic segmentation of deep brain structures. These three new techniques show the adaptability of our method to various problems. Our different segmentation methods are better than most of nowadays techniques, speaking of computation time or segmentation accuracy. (authors)

Orthonormal bases for α-modulation spaces

DEFF Research Database (Denmark)

Nielsen, Morten

We construct an orthonormal basis for the family of bi-variate a-modulation spaces. The construction is based on local trigonometric bases, and the basis elements are closely related to so-called brushlets. As an application, we show that m-term nonlinear approximation with the system in an a......-modulation space can be completely characterized....

Physical properties of Bi doped CdTe thin films grown by CSVT and their influence on the CdS/CdTe solar cells PV-properties

International Nuclear Information System (INIS)

Vigil-Galan, O.; Sanchez-Meza, E.; Ruiz, C.M.; Sastre-Hernandez, J.; Morales-Acevedo, A.; Cruz-Gandarilla, F.; Aguilar-Hernandez, J.; Saucedo, E.; Contreras-Puente, G.; Bermudez, V.

2007-01-01

The physical properties of Bi doped CdTe films, grown on glass substrates by the Closed Space Transport Vapour (CSVT) method, from different Bi doped CdTe powders are presented. The CdTe:Bi films were characterized using Photoluminescence, Hall effect, X-Ray diffraction, SEM and Photoconductivity measurements. Moreover, CdS/CdTe:Bi solar cells were made and their characteristics like short circuit current density (J sc ), open circuit voltage (V OC ), fill factor (FF) and efficiency (η) were determined. These devices were fabricated from Bi doped CdTe layers deposited on CdS with the same growth conditions than those used for the single CdTe:Bi layers. A correlation between the CdS/CdTe:Bi solar cell characteristics and the physical properties of the Bi doped CdTe thin films are presented and discussed

Calorimetric investigations of U-Bi system

International Nuclear Information System (INIS)

Agarwal, Renu; Joshi, A.R.

2013-01-01

U 0.333 Bi 0.667 is a compound that may form on breach of clad during reactor operation with metallic fuel and lead-bismuth coolant. Therefore, enthalpy of mixing of U-Bi liquid solution in limited composition range and enthalpy of formation of U 0.333 Bi 0.667 compound were measured by high temperature calorimetry. The enthalpy of mixing follows subregular solution model and enthalpy of formation U 0.333 Bi 0.667 from U(l) and Bi(l) at 843 K was -52.5 kJ/mol and -40.8 kJ/mol from U(s) and Bi(s) at 298.15 K. Both enthalpy of mixing and enthalpy of formation of intermetallic compound obtained experimentally were compared with Miedema model values. (author)

Segmentation of High Angular Resolution Diffusion MRI using Sparse Riemannian Manifold Clustering

Science.gov (United States)

Wright, Margaret J.; Thompson, Paul M.; Vidal, René

2015-01-01

We address the problem of segmenting high angular resolution diffusion imaging (HARDI) data into multiple regions (or fiber tracts) with distinct diffusion properties. We use the orientation distribution function (ODF) to represent HARDI data and cast the problem as a clustering problem in the space of ODFs. Our approach integrates tools from sparse representation theory and Riemannian geometry into a graph theoretic segmentation framework. By exploiting the Riemannian properties of the space of ODFs, we learn a sparse representation for each ODF and infer the segmentation by applying spectral clustering to a similarity matrix built from these representations. In cases where regions with similar (resp. distinct) diffusion properties belong to different (resp. same) fiber tracts, we obtain the segmentation by incorporating spatial and user-specified pairwise relationships into the formulation. Experiments on synthetic data evaluate the sensitivity of our method to image noise and the presence of complex fiber configurations, and show its superior performance compared to alternative segmentation methods. Experiments on phantom and real data demonstrate the accuracy of the proposed method in segmenting simulated fibers, as well as white matter fiber tracts of clinical importance in the human brain. PMID:24108748

Exploratory Bi-factor Analysis: The Oblique Case

OpenAIRE

Jennrich, Robert L.; Bentler, Peter M.

2011-01-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford (1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler (2011) introduced an exploratory form of bi-factor analysis that does not require one to provide an explicit bi-factor structure a priori. They use exploratory factor analysis and a bi-factor rotation criterion designed to produce a rotated loading mat...

A reusable anatomically segmented digital mannequin for public health communication.

Science.gov (United States)

Fujieda, Kaori; Okubo, Kosaku

2016-01-01

The ongoing development of world wide web technologies has facilitated a change in health communication, which has now become bi-directional and encompasses people with diverse backgrounds. To enable an even greater role for medical illustrations, a data set, BodyParts3D, has been generated and its data set can be used by anyone to create and exchange customised three-dimensional (3D) anatomical images. BP3D comprises more than 3000 3D object files created by segmenting a digital mannequin in accordance with anatomical naming conventions. This paper describes the methodologies and features used to generate an anatomically correct male mannequin.

Three-dimensional rendering of segmented object using matlab - biomed 2010.

Science.gov (United States)

Anderson, Jeffrey R; Barrett, Steven F

2010-01-01

The three-dimensional rendering of microscopic objects is a difficult and challenging task that often requires specialized image processing techniques. Previous work has been described of a semi-automatic segmentation process of fluorescently stained neurons collected as a sequence of slice images with a confocal laser scanning microscope. Once properly segmented, each individual object can be rendered and studied as a three-dimensional virtual object. This paper describes the work associated with the design and development of Matlab files to create three-dimensional images from the segmented object data previously mentioned. Part of the motivation for this work is to integrate both the segmentation and rendering processes into one software application, providing a seamless transition from the segmentation tasks to the rendering and visualization tasks. Previously these tasks were accomplished on two different computer systems, windows and Linux. This transition basically limits the usefulness of the segmentation and rendering applications to those who have both computer systems readily available. The focus of this work is to create custom Matlab image processing algorithms for object rendering and visualization, and merge these capabilities to the Matlab files that were developed especially for the image segmentation task. The completed Matlab application will contain both the segmentation and rendering processes in a single graphical user interface, or GUI. This process for rendering three-dimensional images in Matlab requires that a sequence of two-dimensional binary images, representing a cross-sectional slice of the object, be reassembled in a 3D space, and covered with a surface. Additional segmented objects can be rendered in the same 3D space. The surface properties of each object can be varied by the user to aid in the study and analysis of the objects. This inter-active process becomes a powerful visual tool to study and understand microscopic objects.

Characterization and study of dielectric and electrical properties of CaBi4Ti4O_1_5 (CBT) added with Bi_2O_3

International Nuclear Information System (INIS)

Freitas, D.B.; Campos Filho, M.C.; Sales, J.C.; Silva, P.M.O.; Sombra, A.S.

2011-01-01

The ceramic perovskite CaBi_4Ti_4O_1_5 (CBT) of space group A21am, Aurivillius family with deficiency A_5B_4O_1_5 cation has been prepared by solid state method in a planetary ball mill of high energy. The reagents samples were ground and calcined and then added with Bi_2O_3 (2% wt.) This work aims to characterize by X-ray diffraction to study the electrical properties and dielectric properties of (CBT). The x-ray diffraction revealed the formation of single orthorhombic phase. As for the dielectric properties (dielectric constant and dielectric loss) were measured at 30 deg C to 450 deg C, through which can be verified the presence of thermally activated processes. This phase has properties very relevant for possible use in capacitive devices, miniaturized filters, dielectric resonators antennas and oscillators. (author)

Joint Rendering and Segmentation of Free-Viewpoint Video

Directory of Open Access Journals (Sweden)

Ishii Masato

2010-01-01

Full Text Available Abstract This paper presents a method that jointly performs synthesis and object segmentation of free-viewpoint video using multiview video as the input. This method is designed to achieve robust segmentation from online video input without per-frame user interaction and precomputations. This method shares a calculation process between the synthesis and segmentation steps; the matching costs calculated through the synthesis step are adaptively fused with other cues depending on the reliability in the segmentation step. Since the segmentation is performed for arbitrary viewpoints directly, the extracted object can be superimposed onto another 3D scene with geometric consistency. We can observe that the object and new background move naturally along with the viewpoint change as if they existed together in the same space. In the experiments, our method can process online video input captured by a 25-camera array and show the result image at 4.55 fps.

Unusual Concentration Induced Antithermal Quenching of the Bi(2+) Emission from Sr2P2O7:Bi(2.).

Science.gov (United States)

Li, Liyi; Peng, Mingying; Viana, Bruno; Wang, Jing; Lei, Bingfu; Liu, Yingliang; Zhang, Qinyuan; Qiu, Jianrong

2015-06-15

The resistance of a luminescent material to thermal quenching is essential for the application in high power LEDs. Usually, thermal luminescence quenching becomes more and more serious as the activator concentration increases. Conversely, we found here that a red phosphor Sr2P2O7:Bi(2+) is one of the exceptions to this as we studied the luminescence properties at low (10-300 K) and high (300-500 K) temperatures. As Bi(2+) ions are incorporated into Sr2P2O7, they exhibit the emissions at ∼660 and ∼698 nm at room temperature and are encoded, hereafter, as Bi(1) and Bi(2) due to the substitutions for two different crystallographic sites Sr(1) and Sr(2), respectively, in the compound. However, they will not substitute for these sites equally. At lower dopant concentration, they will occupy preferentially Sr(2) sites partially due to size match. As the concentration increases, more Bi(2+) ions start to occupy the Sr(1) sites. This can be verified by the distinct changes of emission intensity ratio of Bi(2) to Bi(1). As environment temperature increases, the thermal quenching happens, but it can be suppressed by the Bi(2+) concentration increase. This becomes even more pronounced in Bi(2+) heavily doped sample as we decompose the broad emission band into separated Bi(1) and Bi(2) Gaussian peaks. For the sample, the Bi(1) emission at ∼660 nm even shows antithermal-quenching particularly at higher temperatures. This phenomenon is accompanied by the blue shift of the overall emission band and almost no changes of lifetimes. A mechanism is proposed due to volume expansion of the unit cell, the increase of Bi(1) content, and temperature dependent energy transfer between Bi(2) and Bi(1). This work helps us better understand the complex luminescent behavior of Bi(2+) doped materials, and it will be helpful to design in the future the heavily doped phosphor for WLEDs with even better resistance to thermal quenching.

Light regulated I–V hysteresis loop of Ag/BiFeO{sub 3}/FTO thin film

Energy Technology Data Exchange (ETDEWEB)

Wei, Lujun; Sun, Bai; Zhao, Wenxi; Li, Hongwei; Chen, Peng, E-mail: pchen@swu.edu.cn

2017-01-30

A hysteresis loop of current–voltage characteristics based multiferroic BiFeO{sub 3} nanoribbons memory device is observed. Moreover, the white-light can greatly regulate both the current–voltage hysteresis loop and the ferroelectric hysteresis loop. The stored space charges within the electrodes/BiFeO{sub 3} interface can lead to hysteresis-type I–V characteristics of Ag/BiFeO{sub 3}/FTO devices. The white-light controlled I–V loop and ferroelectric loop result from photon-generated carries. Since the I–V hysteresis loop and ferroelectric hysteresis loop have a potential application prospect to the memory devices, these two white-light controlled the hysteresis loops curves are likely to provide promising opportunity for developing the multi-functional memory devices.

Candidate Smoke Region Segmentation of Fire Video Based on Rough Set Theory

Directory of Open Access Journals (Sweden)

Yaqin Zhao

2015-01-01

Full Text Available Candidate smoke region segmentation is the key link of smoke video detection; an effective and prompt method of candidate smoke region segmentation plays a significant role in a smoke recognition system. However, the interference of heavy fog and smoke-color moving objects greatly degrades the recognition accuracy. In this paper, a novel method of candidate smoke region segmentation based on rough set theory is presented. First, Kalman filtering is used to update video background in order to exclude the interference of static smoke-color objects, such as blue sky. Second, in RGB color space smoke regions are segmented by defining the upper approximation, lower approximation, and roughness of smoke-color distribution. Finally, in HSV color space small smoke regions are merged by the definition of equivalence relation so as to distinguish smoke images from heavy fog images in terms of V component value variety from center to edge of smoke region. The experimental results on smoke region segmentation demonstrated the effectiveness and usefulness of the proposed scheme.

[Flipping moxibustion of Hui medicine combined with western medication for rheumatoid arthritis with cold dampness bi syndrome].

Science.gov (United States)

Wang, Shunji; Ye, Gaxi; Zhang, Yu; Guan, Shuting; Liu, Xiufen; Ren, Wenjing

2017-10-12

To compare the effects of flipping moxibustion of Hui medicine combined with western medication and simple western medication for rheumatoid arthritis with cold dampness bi syndrome. Eighty patients were randomly assigned into an observation group and a control group, 40 cases in each group. Oral methotrexate (1 time a week) and sulfasalazine (twice a day except the day for methotrexate) were used in the two groups. Patients in the observation group were treated with flipping moxibustion of Hui medicine, twice a week. The main acupoints were Shenshu (BL 23), Guanyuan (CV 4), Zusanli (ST 36), Yinlingquan (SP 9), and the matching acupoints were in the meridians related to the disease location. All the treatment was given for continuous 4 weeks. The TCM symptom score, visual analogue scale (VAS) score, blood sedimentation (ESR), rheumatoid factor (RF) and C-reactive protein (CRP) were observed before and after treatment. The effect was evaluated. The total effect rate in the observation group was 95.0% (38/40), which was better than 77.5% (31/40) in the control group ( P bi syndrome are better than simple western medication, which are safer and more effective.

High pressure synthesis of BiS2

DEFF Research Database (Denmark)

Søndergaard-Pedersen, Simone; Nielsen, Morten Bormann; Bremholm, Martin

crystal structures and electrical properties.1,2 Up until now, the most sulfur rich phase in the Bi-S phase diagram was Bi2S3.3 For BiS2 the Bi atoms have anisotropic charge distribution and more complex structures are expected when comparing the layered structures of transition metal dichalcogenides....... The possibilities of using high pressure synthesis to discover new phases in the Bi-S binary system were investigated as early as the 1960’s.4 The research led to discovery of a compound with BiS2 stoichiometry, but no structure solution of BiS2 was reported. A reason behind making this new phase is to study...... the physical properties since the related compound Bi2S3 is known to be a thermoelectric material.5 In this research the BiS2 compound was synthesized by a high pressure and high temperature method using a multi-anvil large volume press and the structure was solved by single crystal diffraction. The structure...

Internal friction behavior of liquid Bi-Sn alloys

International Nuclear Information System (INIS)

Wu Aiqing; Guo Lijun; Liu Changsong; Jia Erguang; Zhu Zhengang

2005-01-01

Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480 - bar Cand another at about 830 - bar C. Only a single internal-friction peak at about 830 - bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids

Internal friction behavior of liquid Bi-Sn alloys

Energy Technology Data Exchange (ETDEWEB)

Wu Aiqing [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Guo Lijun [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Liu Changsong [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Jia Erguang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China); Zhu Zhengang [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, P.O. Box 1129, Hefei 230031 (China)]. E-mail: zgzhu@issp.ac.cn

2005-12-01

Pure Bi and Sn and four Bi-Sn alloys distributed on the entire concentration range were selected for internal-friction investigation over a wide temperature range. There exist two peaks in the plots of internal friction versus temperature for liquid Sn, Bi-Sn60 and Bi-Sn90 alloys, one peak being located at about 480{sup -}bar Cand another at about 830{sup -}bar C. Only a single internal-friction peak at about 830{sup -}bar C occurs in liquid Bi-Sn43 (eutectic composition). No internal-friction peak appears in liquid Bi-Sn20 alloy and pure Bi. The height of the internal-friction peaks depends on the content of Sn. The present finding suggests that Sn-rich Bi-Sn alloys may inherit the internal-friction behaviors of pure Sn, whereas Bi-rich Bi-Sn alloy seems to be like pure Bi. The position of the internal-friction peaks is frequency dependent, which resembles the internal-friction feature in structure transition in solids.

Investigation of the phase formation and dielectric properties of Bi7Ta3O18

International Nuclear Information System (INIS)

Chon, M.P.; Tan, K.B.; Khaw, C.C.; Zainal, Z.; Taufiq Yap, Y.H.; Chen, S.K.; Tan, P.Y.

2014-01-01

Highlights: • Synthesis condition of Bi 7 TaO 3 O 18 had been determined. • Recombination of intermediate BiTaO 4 and Bi 3 TaO 7 phases are required for the Bi 7 TaO 3 O 18 phase formation. • Stable material as confirmed by thermal and structural analyses. • Typical ferroelectric showing high dielectric constants and low losses. • Resonance and thermal activated polarisation processes are responsible for the excellent dielectric characteristic. -- Abstract: Polycrystalline Bi 7 Ta 3 O 18 was synthesised at the firing temperature of 950 °C over 18 h via conventional solid state method. It crystallised in a monoclinic system with space group C2/m, Z = 4 similar to that reported diffraction pattern in the Inorganic Crystal Structure Database (ICSD), 1-89-6647. The refined lattice parameters were a = 34.060 (3) Å, b = 7.618 (9) Å, c = 6.647 (6) Å with α = γ = 90° and β = 109.210 (7), respectively. The intermediate phase was predominantly in high-symmetry cubic structure below 800 °C and finally evolved into a low-symmetry monoclinic structured, Bi 7 Ta 3 O 18 at 950 °C. The sample contained grains of various shapes with different orientations in the size ranging from 0.33–22.70 μm. The elemental analysis showed the sample had correct stoichiometry with negligible Bi 2 O 3 loss. Bi 7 Ta 3 O 18 was thermally stable and it exhibited a relatively high relative permittivity, 241 and low dielectric loss, 0.004 at room temperature, ∼30 °C and frequency of 1 MHz

Tracheal Atresia with Segmental Esophageal Duplication: An Unusual Anatomic Arrangement.

Science.gov (United States)

Gaerty, Kirsten; Thomas, Joseph T; Petersen, Scott; Tan, Edwin; Kumar, Sailesh; Gardener, Glenn; Armes, Jane

2016-01-01

An unusual anatomic configuration of segmental tracheal agenesis/atresia with esophageal duplication on autopsy in a fetus that demised in utero at 29 weeks is reported. The mother was scanned initially for a cardiac anomaly at 20 weeks and on follow-up scan at 27 weeks had polyhydramnios and underwent amnioreduction. The final autopsy diagnosis was vertebral, ano-rectal, cardiac, tracheoesophageal, renal, and limb malformations (VACTERL). We discuss the autopsy findings along with the embryological mechanisms and compare the configuration with Floyd's classification for tracheal agenesis. The difficulties in prenatal diagnosis are discussed.

Solvothermal modification of BiOCl nanosheets with Bi nanoparticles using ascorbic acid as reductant and the superoxide radicals dominated photocatalytic performance

Science.gov (United States)

Cui, Zhankui; Gao, Keke; Ge, Suxiang; Fa, Wenjun

2017-11-01

BiOCl nanosheets were solvothermally modified with Bi nanoparticles (NPs) using ascorbic acid as the reductant. The structures of Bi/BiOCl composites were characterized by XRD, Raman spectroscopy, FTIR spectroscopy and SEM. The light absorption properties were measured by UV-vis-NIR spectroscopy. The photocatalytic performances were evaluated by photodegrading methyl orange (MO) and the photocatalytic mechanism was investigated using trapping experiments and a fluorescent probe method. The results show that Bi NPs are uniformly distributed on the surfaces of BiOCl nanosheets and the modification amount of Bi NPs could be well controlled because of the mild property of ascorbic acid as reducing agent. The photocatalytic activities for the composites are improved obviously and the best photocatalytic performance is obtained when the weight ratio of Bi and BiOCl is1:10 and the photochemical reaction rate is 3.5 times that of pure BiOCl nanosheets and 19.7 times of Bi powders. The enhanced photocatalytic efficiency is ascribed to the favorable formation of dominant \\cdot O2- radicals caused by the increased photoinduced electrons from both Bi NPs and BiOCl nanosheets.

Cryo-EM Structure Determination Using Segmented Helical Image Reconstruction.

Science.gov (United States)

Fromm, S A; Sachse, C

2016-01-01

Treating helices as single-particle-like segments followed by helical image reconstruction has become the method of choice for high-resolution structure determination of well-ordered helical viruses as well as flexible filaments. In this review, we will illustrate how the combination of latest hardware developments with optimized image processing routines have led to a series of near-atomic resolution structures of helical assemblies. Originally, the treatment of helices as a sequence of segments followed by Fourier-Bessel reconstruction revealed the potential to determine near-atomic resolution structures from helical specimens. In the meantime, real-space image processing of helices in a stack of single particles was developed and enabled the structure determination of specimens that resisted classical Fourier helical reconstruction and also facilitated high-resolution structure determination. Despite the progress in real-space analysis, the combination of Fourier and real-space processing is still commonly used to better estimate the symmetry parameters as the imposition of the correct helical symmetry is essential for high-resolution structure determination. Recent hardware advancement by the introduction of direct electron detectors has significantly enhanced the image quality and together with improved image processing procedures has made segmented helical reconstruction a very productive cryo-EM structure determination method. © 2016 Elsevier Inc. All rights reserved.

Bi-level positive pressure ventilation and adaptive servo ventilation in patients with heart failure and Cheyne-Stokes respiration.

Science.gov (United States)

Fietze, Ingo; Blau, Alexander; Glos, Martin; Theres, Heinz; Baumann, Gert; Penzel, Thomas

2008-08-01

Nocturnal positive pressure ventilation (PPV) has been shown to be effective in patients with impaired left ventricular ejection fraction (LVEF) and Cheyne-Stokes respiration (CSR). We investigated the effect of a bi-level PPV and adaptive servo ventilation on LVEF, CSR, and quantitative sleep quality. Thirty-seven patients (New York heart association [NYHA] II-III) with LVEFCSR were investigated by electrocardiography (ECG), echocardiography and polysomnography. The CSR index (CSRI) was 32.3+/-16.2/h. Patients were randomly treated with bi-level PPV using the standard spontaneous/timed (S/T) mode or with adaptive servo ventilation mode (AutoSetCS). After 6 weeks, 30 patients underwent control investigations with ECG, echocardiography, and polysomnography. The CSRI decreased significantly to 13.6+/-13.4/h. LVEF increased significantly after 6 weeks of ventilation (from 25.1+/-8.5 to 28.8+/-9.8%, plevel PPV and adaptive servo ventilation: the CSRI decreased more in the AutoSetCS group while the LVEF increased more in the bi-level PPV group. Administration of PPV can successfully attenuate CSA. Reduced CSA may be associated with improved LVEF; however, this may depend on the mode of PPV. Changed LVEF is evident even in the absence of significant changes in blood pressure.

The effect of the X-Stop implantation on intervertebral foramen, segmental spinal canal length and disc space in elderly patients with lumbar spinal stenosis.

Science.gov (United States)

Wan, Zongmiao; Wang, Shaobai; Kozanek, Michal; Xia, Qun; Mansfield, Frederick L; Lü, Guohua; Wood, Kirkham B; Li, Guoan

2012-03-01

To evaluate the biomechanical effect of the X-Stop device on the intervertebral foramen (IVF) and segmental spinal canal length (SSCL), as well as the intervertebral disc space at the implanted and the adjacent segments in patients with lumbar spinal stenosis (LSS). Eight elderly patients with LSS, scheduled for X-stop implantation, were CT or MRI scanned to construct 3D vertebral models (L2-S1). Before and after the surgery, each patient was also imaged using a dual-fluoroscopic image system during weight-bearing standing and maximum extension-flexion. The positions of the vertebrae were then determined using an established 2D-3D model matching method. The data revealed that the postoperative IVF area was significantly increased by 32.9% (or 32 mm2) (pspace of the implanted level was significantly decreased from 8.0 to 6.6 mm during standing. The X-Stop implantation efficiently enlarged the IVF area in the elderly patients with LSS at the operated level with little biomechanical effect immediately on the superior and inferior adjacent levels. However, it reduced the anterior disc space at the implanted level.

Upper airway segmentation and dimensions estimation from cone-beam CT image datasets

Energy Technology Data Exchange (ETDEWEB)

Shi, Hongjian; Scarfe, W.C. [Louisville Univ., KY (United States). School of Dentistry; Farman, A.G. [Louisville Univ., KY (United States). School of Dentistry; Louisville Univ., KY (United States). Div. of Radiology and Imaging Science

2006-11-15

Objective: To segment and measure the upper airway using cone-beam computed tomography (CBCT). This information may be useful as an imaging biomarker in the diagnostic assessment of patients with obstructive sleep apnea and in the planning of any necessary therapy. Methods: With Institutional Review Board Approval, anonymous CBCT datasets from subjects who had been imaged for a variety of conditions unrelated to the airway were evaluated. DICOM images were available. A segmentation algorithm was developed to separate the bounded upper airway and measurements were performed manually to determine the smallest cross-sectional area and the anteriorposterior distance of the retropalatal space (RP-SCA and RP-AP, respectively) and retroglossal space (RG-SCA and RG-AP, respectively). A segmentation algorithm was developed to separate the bounded upper airway and it was applied to determine RP-AP, RG-AP, the smallest transaxial-sectional area (TSCA) and largest sagittal view airway area (LCSA). A second algorithm was created to evaluate the airway volume within this bounded upper airway. Results: Measurements of the airway segmented automatically by the developed algorithm agreed with those obtained using manual segmentation. The corresponding volumes showed only very small differences considered clinically insignificant. Conclusion: Automatic segmentation of the airway imaged using CBCT is feasible and this method can be used to evaluate airway cross-section and volume comparable to measurements extracted using manual segmentation. (orig.)

Phonons of single quintuple Bi 2 Te 3 and Bi 2 Se 3 films and bulk materials

KAUST Repository

Cheng, Wei; Ren, Shang-Fen

2011-01-01

Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi 2Te3 and Bi2Se3 quintuple films are explained. © 2011 American Physical Society.

Phonons of single quintuple Bi 2 Te 3 and Bi 2 Se 3 films and bulk materials

KAUST Repository

Cheng, Wei

2011-03-10

Phonons of single quintuple films of Bi2Te3 and Bi2Se3 and corresponding bulk materials are calculated in detail by MedeA (a trademark of Materials Design) and Vienna ab initio simulation package (VASP). The calculated results with and without spin-orbit couplings are compared, and the important roles that the spin-orbit coupling plays in these materials are discussed. A symmetry breaking caused by the anharmonic potentials around Bi atoms in the single quintuple films is identified and discussed. The observed Raman intensity features in Bi 2Te3 and Bi2Se3 quintuple films are explained. © 2011 American Physical Society.

Demonstration of surface transport in a hybrid Bi2Se3/Bi2Te3 heterostructure

OpenAIRE

Zhao, Yanfei; Chang, Cui-Zu; Jiang, Ying; DaSilva, Ashley; Sun, Yi; Wang, Huichao; Xing, Ying; Wang, Yong; He, Ke; Ma, Xucun; Xue, Qi-Kun; Wang, Jian

2013-01-01

In spite of much work on topological insulators (TIs), systematic experiments for TI/TI heterostructures remain absent. We grow a high quality heterostructure containing single quintuple layer (QL) of Bi2Se3 on 19 QLs of Bi2Te3 and compare its transport properties with 20 QLs Bi2Se3 and 20 QLs Bi2Te3. All three films are grown on insulating sapphire (0001) substrates by molecular beam epitaxy (MBE). In situ angle-resolved photoemission spectroscopy (ARPES) provides direct evidence that the su...

Comparative study of phase structure and dielectric properties for K0.5Bi0.5TiO3-BiAlO3 and LaAlO3-BiAlO3

International Nuclear Information System (INIS)

Hou, Yudong; Zheng, Mupeng; Si, Meiju; Cui, Lei; Zhu, Mankang; Yan, Hui

2013-01-01

In this work, two perovskite-type compounds, K 0.5 Bi 0.5 TiO 3 and LaAlO 3 , have been selected as host material to incorporate with BiAlO 3 using a solid-state reaction route. The phase evolution and dielectric properties for both systems have been investigated in detail. For the K 0.5 Bi 0.5 TiO 3 -BiAlO 3 system, it is interesting to find that when using Bi 2 O 3 , Al 2 O 3 , K 2 CO 3 , and TiO 2 as starting materials, the formed compounds are K 0.5 Bi 0.5 TiO 3 -K 0.5 Bi 4.5 Ti 4 O 15 and Al 2 O 3 only plays a dopant role. There are two distinct dielectric peaks appearing in the patterns of temperature dependence of dielectric constant, corresponding to the phase-transition points of perovskite-type K 0.5 Bi 0.5 TiO 3 and Aurivillius-type K 0.5 Bi 4.5 Ti 4 O 15 , independently. In comparison, using Bi 2 O 3 , Al 2 O 3 , and La 2 O 3 as starting materials, the pure perovskite phase LaAlO 3 -BiAlO 3 can be obtained. Compared to the inherent paraelectric behavior in LaAlO 3 , the diffuse phase-transition phenomena can be observed in the LaAlO 3 -BiAlO 3 binary system, which corresponds well to the Vogel-Fulcher (VF) relationship. Moreover, compared to pure LaAlO 3 , the synthesized LaAlO 3 -BiAlO 3 compound shows enhanced dielectric properties, which are promising in application as gate dielectric materials. (copyright 2013 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

Segmentation: Identification of consumer segments

DEFF Research Database (Denmark)

Høg, Esben

2005-01-01

It is very common to categorise people, especially in the advertising business. Also traditional marketing theory has taken in consumer segments as a favorite topic. Segmentation is closely related to the broader concept of classification. From a historical point of view, classification has its...... origin in other sciences as for example biology, anthropology etc. From an economic point of view, it is called segmentation when specific scientific techniques are used to classify consumers to different characteristic groupings. What is the purpose of segmentation? For example, to be able to obtain...... a basic understanding of grouping people. Advertising agencies may use segmentation totarget advertisements, while food companies may usesegmentation to develop products to various groups of consumers. MAPP has for example investigated the positioning of fish in relation to other food products...

Crystalline structure and XMCD studies of Co40Fe40B20 grown on Bi2Te3, BiTeI and Bi2Se3

OpenAIRE

Kaveev, A. K.; Sokolov, N. S.; Suturin, S. M.; Zhiltsov, N. S.; Golyashov, V. A.; Tereshchenko, O. E.; Prosvirin, I. P.; Kokh, K. A.; Sawada, M.

2018-01-01

Epitaxial films of Co40Fe40B20 (further - CoFeB) were grown on Bi2Te3(001) and Bi2Se3(001) substrates by laser molecular beam epitaxy (LMBE) technique at 200-400C. Bcc-type crystalline structure of CoFeB with (111) plane parallel to (001) plane of Bi2Te3 was observed, in contrast to polycrystalline CoFeB film formed on Bi2Se3(001) at RT using high-temperature seeding layer. Therefore, structurally ordered ferromagnetic thin films were obtained on the topological insulator surface for the firs...

Thermal analysis and phase diagrams of the LiF BiF{sub 3} e NaF BiF{sub 3} systems; Analise termica e diagramas de fase dos sistemas LiF-BiF{sub 3} e NaF-BiF{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Nakamura, Gerson Hiroshi de Godoy

2013-07-01

Investigations of the binary systems LiF-BiF{sub 3} and NaF-BiF{sub 3} were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF{sub 3}) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF{sub 3} to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF{sub 3} were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF{sub 4}, decomposes into LiF and a liquid phase. The NaF-BiF{sub 3} system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF{sub 3}) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF{sub 4} was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF{sub 4}, NaBiF{sub 4} and a solid solution of NaF and BiF{sub 3} called {sup I.} The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

Crystal structure of ferroelectric Bi{sub 2}VO{sub 5.5}

Energy Technology Data Exchange (ETDEWEB)

Sooryanarayana, K.; Guru Row, T.N.; Varma, K.B.R. [Indian Inst. of Science, Bangalore (India)

1997-12-01

The structure of the {alpha}-phase of bismuth vanadate Bi{sub 2}VO{sub 5.5} has been determined using single crystal X-ray diffraction data in the space group Aba2. The refinement involves a well defined disorder at the vanadium site, which incorporates the features of the superlattice structure with vanadium tetrahedra and oxygen-deficient octahedra that is displaced about the twofold axis.

Radiographic features of congenital segmental dilation of the intestine in a german shepherd dog.

Science.gov (United States)

Johnson, Laura; Simone, Kristina; Cullen, John; Talley, Ashley; Cohen, Eli B

2017-12-04

A 10-week-old spayed female German Shepherd Dog was presented for acute vomiting and diarrhea. There was no reported foreign body or toxin ingestion. Radiographs showed a severely (∼11 × 7 cm), focally distended right abdominal intestinal segment containing gas and soft tissue material. Other small intestinal segments were segmentally gas distended. Celiotomy identified a ∼9 cm focally dilated segment at the jejunoileal junction with no aborad luminal obstruction. Resection and anastomosis of the dilation was performed. Histopathology showed mild mucosal inflammation, but otherwise normal wall layering and autonomic ganglia. Radiographic and histopathologic findings were consistent with congenital segmental dilation of the intestine. © 2017 American College of Veterinary Radiology.

Highly efficient visible-light-induced photocatalytic activity of Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts

Energy Technology Data Exchange (ETDEWEB)

Chaiwichian, Saranyoo [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai50200 (Thailand); Inceesungvorn, Burapat [Department of Chemistry, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Wetchakun, Khatcharin [Program of Physics, Faculty of Science, Ubon Ratchathani Rajabhat University, Ubon Ratchathani 34000 (Thailand); Phanichphant, Sukon [Materials Science Research Center, Faculty of Science, Chiang Mai University, Chiang Mai 50200 (Thailand); Kangwansupamonkon, Wiyong [National Nanotechnology Center, Thailand Science Park, Phahonyotin Road, Klong 1, Klong Luang, Phathumthani 12120 (Thailand); Wetchakun, Natda, E-mail: natda_we@yahoo.com [Department of Physics and Materials Science, Faculty of Science, Chiang Mai University, Chiang Mai50200 (Thailand)

2014-06-01

Highlights: • Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts were obtained using hydrothermal method. • Physicochemical properties played a significant role on photocatalytic efficiency. • Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterogeneous structures were greatly enhanced for degradation of MB. • A tentative mechanism of charge transfer process in MB degradation was proposed. - Abstract: The Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts were synthesized by hydrothermal method. Physical properties of the heterojunction photocatalyst samples were studied by X-ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) techniques. The XRD results indicated that BiVO{sub 4} retain monoclinic and tetragonal structures, while Bi{sub 2}WO{sub 6} presented as orthorhombic structure. The Brunauer, Emmett and Teller (BET) adsorption–desorption of nitrogen gas for specific surface area determination at the temperature of liquid nitrogen was performed on all samples. UV–vis diffuse reflectance spectra (UV–vis DRS) were used to identify the absorption range and band gap energy of the heterojunction photocatalysts. The photocatalytic performance of Bi{sub 2}WO{sub 6}/BiVO{sub 4} heterojunction photocatalysts was studied via the photodegradation of methylene blue (MB) under visible light irradiation. The results indicated that the heterojunction photocatalyst at 0.5:0.5 mole ratio of Bi{sub 2}WO{sub 6}:BiVO{sub 4} shows the highest photocatalytic activity.

Exploratory Bi-Factor Analysis: The Oblique Case

Science.gov (United States)

Jennrich, Robert I.; Bentler, Peter M.

2012-01-01

Bi-factor analysis is a form of confirmatory factor analysis originally introduced by Holzinger and Swineford ("Psychometrika" 47:41-54, 1937). The bi-factor model has a general factor, a number of group factors, and an explicit bi-factor structure. Jennrich and Bentler ("Psychometrika" 76:537-549, 2011) introduced an exploratory form of bi-factor…

Segmentation editing improves efficiency while reducing inter-expert variation and maintaining accuracy for normal brain tissues in the presence of space-occupying lesions

International Nuclear Information System (INIS)

Deeley, M A; Chen, A; Cmelak, A; Malcolm, A; Jaboin, J; Niermann, K; Yang, Eddy S; Yu, David S; Datteri, R D; Noble, J; Dawant, B M; Donnelly, E; Moretti, L

2013-01-01

Image segmentation has become a vital and often rate-limiting step in modern radiotherapy treatment planning. In recent years, the pace and scope of algorithm development, and even introduction into the clinic, have far exceeded evaluative studies. In this work we build upon our previous evaluation of a registration driven segmentation algorithm in the context of 8 expert raters and 20 patients who underwent radiotherapy for large space-occupying tumours in the brain. In this work we tested four hypotheses concerning the impact of manual segmentation editing in a randomized single-blinded study. We tested these hypotheses on the normal structures of the brainstem, optic chiasm, eyes and optic nerves using the Dice similarity coefficient, volume, and signed Euclidean distance error to evaluate the impact of editing on inter-rater variance and accuracy. Accuracy analyses relied on two simulated ground truth estimation methods: simultaneous truth and performance level estimation and a novel implementation of probability maps. The experts were presented with automatic, their own, and their peers’ segmentations from our previous study to edit. We found, independent of source, editing reduced inter-rater variance while maintaining or improving accuracy and improving efficiency with at least 60% reduction in contouring time. In areas where raters performed poorly contouring from scratch, editing of the automatic segmentations reduced the prevalence of total anatomical miss from approximately 16% to 8% of the total slices contained within the ground truth estimations. These findings suggest that contour editing could be useful for consensus building such as in developing delineation standards, and that both automated methods and even perhaps less sophisticated atlases could improve efficiency, inter-rater variance, and accuracy. (paper)

In-Situ Hydrothermal Synthesis of Bi-Bi2O2CO3 Heterojunction Photocatalyst with Enhanced Visible Light Photocatalytic Activity

Science.gov (United States)

Kar, Prasenjit; Maji, Tuhin Kumar; Nandi, Ramesh; Lemmens, Peter; Pal, Samir Kumar

2017-04-01

Bismuth containing nanomaterials recently received increasing attention with respect to environmental applications because of their low cost, high stability and nontoxicity. In this work, Bi-Bi2O2CO3 heterojunctions were fabricated by in-situ decoration of Bi nanoparticles on Bi2O2CO3 nanosheets via a simple hydrothermal synthesis approach. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and high-resolution TEM (HRTEM) were used to confirm the morphology of the nanosheet-like heterostructure of the Bi-Bi2O2CO3 composite. Detailed ultrafast electronic spectroscopy reveals that the in-situ decoration of Bi nanoparticles on Bi2O2CO3 nanosheets exhibit a dramatically enhanced electron-hole pair separation rate, which results in an extraordinarily high photocatalytic activity for the degradation of a model organic dye, methylene blue (MB) under visible light illumination. Cycling experiments revealed a good photochemical stability of the Bi-Bi2O2CO3 heterojunction under repeated irradiation. Photocurrent measurements further indicated that the heterojunction incredibly enhanced the charge generation and suppressed the charge recombination of photogenerated electron-hole pairs.

Studying magnetic structure of Bi doped Co2MnO4 cubic spinel by neutron diffraction

International Nuclear Information System (INIS)

Rajeevan, N.E.; Kaushik, S.D.; Kumar, Ravi

2016-01-01

In present work, we studied effect of Bi doped spinel Bi x Co 2-x MnO 4 (x = 0, 0.05, 0.10, 0.15 and 0.20) samples on their crystal as well as magnetic structure by employing neutron diffraction of wavelength 1.48 A using focusing crystal diffractometer of UGC-DAECSR Mumbai Centre at Dhruva, Trombay, Mumbai, India. The analysis of the neutron diffraction using Fullprof program reveals that crystal structure due to Bi doping remains intact and all the samples have been formed in the cubic spinel structure with Fd3m (space group no. 227). The lattice parameter shows the positive thermal expansion upon Bi doping across the temperature range. In order to understand the implication on the spin structure and magnetism in the detail, temperature dependent neutron diffraction study is carried out on some of the samples (x = 0, 0.1) in the series. The ND pattern of x = 0.1 at 2.9K is shown. The experimental finding in terms of modified magnetic structure upon Bi doping are discussed which are understood in terms of variation in the ferroelectric properties, bond lengths and their effect on the CoO 6 polyhedra. Furthermore, Bi substitution in Co 2 MnO 4 spinel brings in the balance of structural distortion, which affects both ferrimagnetism and ferroelectricity

Facile synthesis of BiOF/Bi{sub 2}O{sub 3}/reduced graphene oxide photocatalyst with highly efficient and stable natural sunlight photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Hu, Limin; Dong, Shuying; Li, Qilu; Feng, Jinglan; Pi, Yunqing; Liu, Menglin [School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China); Sun, Jingyu, E-mail: sunjy-cnc@pku.edu.cn [Center for Nanochemistry (CNC), College of Chemistry and Molecular Engineering, Peking University, Beijing 100871 (China); Sun, Jianhui, E-mail: sunjh@htu.cn [School of Environment, Henan Normal University, Key Laboratory for Yellow River and Huai River Water Environmental and Pollution Control, Ministry of Education, Henan Key Laboratory for Environmental Pollution Control, Xinxiang, Henan 453007 (China)

2015-06-05

Highlights: • A dual Bi-based ball-shaped material BiOF/Bi{sub 2}O{sub 3} were facilely synthesized. • The composition effect of BiOF/Bi{sub 2}O{sub 3}/RGO hybrid were probed for the first time. • The photocatalytic performances were evaluated upon natural sunlight irradiation. • The composites showed a twofold augmentation in the degradation efficiency. • The hybrid photocatalyst can be easily recycled for three times. - Abstract: A facile and efficient route for the controllable synthesis of BiOF/Bi{sub 2}O{sub 3} nanostructures by hydrolysis method was reported, where the as-prepared BiOF/Bi{sub 2}O{sub 3} was subsequently incorporated with reduced graphene oxide (RGO) sheets to form BiOF/Bi{sub 2}O{sub 3}/RGO composites. The obtained BiOF/Bi{sub 2}O{sub 3} and BiOF/Bi{sub 2}O{sub 3}/RGO composites were well characterized with the aid of various techniques to probe their crystallographic, morphological, chemical and optical properties. Photocatalytic capacities of the pure BiOF/Bi{sub 2}O{sub 3} and BiOF/Bi{sub 2}O{sub 3}/RGO composites have been investigated by the degradation of Rhodamine B (RhB)-contained wastewater under natural sunlight irradiation. A twofold augmentation of degradation efficiency was in turn observed for BiOF/Bi{sub 2}O{sub 3}/RGO composites compared with that of pure BiOF/Bi{sub 2}O{sub 3} under the natural sunlight irradiation. The optimum conditions, the effects of the active species and stabilities in photocatalytic performances of the BiOF/Bi{sub 2}O{sub 3}/RGO composites have also been probed.

Superconductivity in Ba sub 1 sub - sub x K sub x BiO sub 3 : possible scenario of spatially separated Fermi-Bose mixture

CERN Document Server

Menushenkov, A P; Kuznetsov, A V; Kagan, M Y

2001-01-01

A new scenario for the metal-insulator phase transition and superconductivity in the perovskite-like bismuthates Ba sub 1 sub - sub x K sub x BiO sub 3 (BKBO) is proposed. It is shown that two types of charge carriers, the local pairs (real-space bosons) and the itinerant electrons, exist in the metallic compound BKBO (x >= 0.37). The real-space bosons are responsible for the charge transport in semiconducting BaBiO sub 3 and for superconductivity in the metallic BKBO. The appearance of the Fermi-liquid state as the percolation threshold is overcome (x >= 0.37) explains the observed metal-insulator phase transition. Because bosons and fermions occupy different types of the octahedral BiO sub 6 complexes, they are separated in real space, and therefore, the spatially separated Fermi-Bose mixture of a new type is likely to be realized in the bismuthates. The nature of superconductivity is consistently explained in the framework of this scenario. A new superconducting oxide Ba sub 1 sub - sub x La sub x PbO sub ...

Value of a probabilistic atlas in medical image segmentation regarding non-rigid registration of abdominal CT scans

Science.gov (United States)

Park, Hyunjin; Meyer, Charles R.

2012-10-01

A probabilistic atlas provides important information to help segmentation and registration applications in medical image analysis. We construct a probabilistic atlas by picking a target geometry and mapping other training scans onto that target and then summing the results into one probabilistic atlas. By choosing an atlas space close to the desired target, we construct an atlas that represents the population well. Image registration used to map one image geometry onto another is a primary task in atlas building. One of the main parameters of registration is the choice of degrees of freedom (DOFs) of the geometric transform. Herein, we measure the effect of the registration's DOFs on the segmentation performance of the resulting probabilistic atlas. Twenty-three normal abdominal CT scans were used, and four organs (liver, spinal cord, left and right kidneys) were segmented for each scan. A well-known manifold learning method, ISOMAP, was used to find the best target space to build an atlas. In summary, segmentation performance was high for high DOF registrations regardless of the chosen target space, while segmentation performance was lowered for low DOF registrations if a target space was far from the best target space. At the 0.05 level of statistical significance, there were no significant differences at high DOF registrations while there were significant differences at low DOF registrations when choosing different targets.

Tl, Bi, and Pb doping in Ba4BiPb2TlO12-δ

International Nuclear Information System (INIS)

Sutto, T.E.; Averill, B.A.

1992-01-01

To determine the effects of different 6s metal concentrations on the superconducting nature of Ba 4 BiPb 2 TlO 12-δ , materials produced via four doping schemes were examined: Ba 4 Bi(Pb, Tl) 3 O 12-δ , Ba 4 -(BiPb) 3 TlO 12-δ , Ba 4 (Bi,Tl) 2 Pb 2 O 12-δ , and Ba 4 Bi x Pb 4-2x Tl x O 12-δ . For the parent compound a value of δ = 0.91 was observed, indicating that approximately 1/4 oxygen atom was missing per cubic subsection of the unit cell. For all samples, the symmetry of the parent compound changed from orthorhombic to tetragonal as the system moved away from the ideal composition. This was usually accompanied by the loss of superconductivity, which exhibited a maximum T c of 10.5 K for the parent compound Ba 4 BiPb 2 TlO 12-δ . Also reported are high-temperature magnetic susceptibility results, which are used to determine the effect of metal substitution on the density of states at the Fermi level. For each set of variants on the parent composition, the onset of superconductivity was accompanied by a significant decrease in the size of the Pauli paramagnetic signal. 16 refs., 6 figs

Considerations about using OLAP Cubes and Self-Service BI Tools for BI Systems’ Development

Directory of Open Access Journals (Sweden)

Gianina MIHAI

2017-12-01

Full Text Available Nowadays, the decision-making process must be an extremely fast one. This is why any decision-maker in a company must obtain information from the multiple available data source used in its transactional systems as easily and as quickly as possible. Business Intelligence (BI systems are the ones that provide the tools necessary for obtaining this information. In this article, we shall present the strengths and weaknesses regarding data analyses in a BI system using OLAP cubes and self-service BI tools.

Bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 with unselectively efficient photocatalytic activity and mechanism insight

Science.gov (United States)

Hao, Lin; Huang, Hongwei; Guo, Yuxi; Du, Xin; Zhang, Yihe

2017-10-01

Fabrication of homo/hetero-junctions by coupling of wide-band gap semiconductor and narrow-band gap semiconductor is desirable as they can achieve a decent balance between photoabsorption and photo-redox ability. Herein, a n-n type bismuth oxychloride homogeneous phasejunction BiOCl/Bi12O17Cl2 was developed by facilely manipulating the basicity in a one-pot hydrothermal process. Compared with BiOCl which only responds to UV light, the photo-responsive range is remarkably extended to visible region. The BiOCl/Bi12O17Cl2 phasejunctions show much higher photocatalytic activity than the single BiOCl and Bi12O17Cl2 toward degradation of methyl orange (MO) under simulated solar light. In particular, it presented a high photo-oxidation ability in degrading diverse industrial contaminants including 2,4-dichlorophenol (2,4-DCP), phenol, bisphenol A (BPA) and tetracycline hydrochloride. Based on a series of photoelectrochemical and photoluminescence measurements, the fortified photocatalytic performance of BiOCl/Bi12O17Cl2 phasejunctions was manifested to be attributed to the efficient separation and transfer efficiencies of photoinduced electron-hole pairs because of the junctional interface formed between BiOCl and Bi12O17Cl2. The study may not only furnish a high-effective photocatalyst in the application of environment purification, but also pave a path to fabricate agnate phase-junctional photocatalyst.

Characterization and study of dielectric and electrical properties of CaBi4Ti4O{sub 15} (CBT) added with Bi{sub 2}O{sub 3}; Caracterizacao e estudo das propriedades eletricas e dieletricas do CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) adicionado com Bi{sub 2}O{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Freitas, D.B.; Campos Filho, M.C.; Sales, J.C.; Silva, P.M.O.; Sombra, A.S. [Universidade Federal do Ceara (UFC), Fortaleza, CE (Brazil)

2011-07-01

The ceramic perovskite CaBi{sub 4}Ti{sub 4}O{sub 15} (CBT) of space group A21am, Aurivillius family with deficiency A{sub 5}B{sub 4}O{sub 15} cation has been prepared by solid state method in a planetary ball mill of high energy. The reagents samples were ground and calcined and then added with Bi{sub 2}O{sub 3} (2% wt.) This work aims to characterize by X-ray diffraction to study the electrical properties and dielectric properties of (CBT). The x-ray diffraction revealed the formation of single orthorhombic phase. As for the dielectric properties (dielectric constant and dielectric loss) were measured at 30 deg C to 450 deg C, through which can be verified the presence of thermally activated processes. This phase has properties very relevant for possible use in capacitive devices, miniaturized filters, dielectric resonators antennas and oscillators. (author)

Thermal analysis and phase diagrams of the LiF BiF3 e NaF BiF3 systems

International Nuclear Information System (INIS)

Nakamura, Gerson Hiroshi de Godoy

2013-01-01

Investigations of the binary systems LiF-BiF 3 and NaF-BiF 3 were performed with the objective of clarifying the thermal behavior and phase equilibria of these systems and their intermediary phases, an important requisite for high-quality crystal growth. Several samples in the entire range of compositions (0 to 100 mol% BiF 3 ) of both systems were subjected to experiments of differential thermal analysis (DTA) and thermogravimetry (TG), and also of differential scanning calorimetry (DSC). A few specific compositions were selected for X-ray diffraction to supplement the experimental data. Due to the high vulnerability of BiF 3 to oxygen contamination, its volatility and propensity to destroy metal parts upon heating, it was necessary to determine the optimal conditions for thermal analysis before investigating the systems themselves. Phase relations in the system LiF-BiF 3 were completely clarified and a phase diagram was calculated and evaluated via the commercial software Factsage. The diagram itself consists in a simple peritectic system in which the only intermediary compound, LiBiF 4 , decomposes into LiF and a liquid phase. The NaF-BiF 3 system could not be completely elucidated and the phase relations in the NaF poor side (> 50% BiF 3 ) are still unknown. In the NaF rich side, however, the possible peritectoid decomposition of the compound NaBiF 4 was identified. In both systems X-ray diffraction yielded crystal structures discrepant with the literature for the intermediary phases, LiBiF 4 , NaBiF 4 and a solid solution of NaF and BiF 3 called I. The observed structures remain unknown and explanations for the discrepancies were proposed. (author)

Multi-Scale Singularity Trees: Soft-Linked Scale-Space Hierarchies

DEFF Research Database (Denmark)

Somchaipeng, Kerawit; Sporring, Jon; Kreiborg, Sven

2005-01-01

We consider images as manifolds embedded in a hybrid of a high dimensional space of coordinates and features. Using the proposed energy functional and mathematical landmarks, images are partitioned into segments. The nesting of image segments occurring at catastrophe points in the scale-space is ...

Orthonormal bases for  α-modulation spaces

DEFF Research Database (Denmark)

Nielsen, Morten

2010-01-01

We construct an orthonormal basis for the family of bi-variate α-modulation spaces. The construction is based on local trigonometric bases, and the basis elements are closely related to so-called brushlets. As an application, we show that m-term nonlinear approximation with the representing system...... in an α-modulation space can be completely characterized....

Ultrahigh vacuum STM/STS studies of the Bi-O surface in Bi2Sr2CuOy single crystals

International Nuclear Information System (INIS)

Ikeda, Kazuto; Tomeno, Izumi; Takamuku, Kenshi; Yamaguchi, Koji; Itti, Rittaporn; Koshizuka, Naoki

1992-01-01

Scanning tunneling microscopic and spectroscopic studies were made on cleaved surfaces of Bi 2 Sr 2 CuO y single crystals using an ultrahigh-vacuum scanning tunneling microscope (UHV-STM). The modulation structures of the Bi-O surface were observed at room temperature with atomic resolution. The tunneling spectra showed electronic gap structures similar to those observed for the Bi-O surface of superconducting Bi-2212 single crystals. This suggests that superconductivity is not directly related to the electronic structure observed in the Bi-O plane. (orig.)

Phase relations and crystal structures in the systems (Bi,Ln)2WO6 and (Bi,Ln)2MoO6 (Ln=lanthanide)

International Nuclear Information System (INIS)

Berdonosov, Peter S.; Charkin, Dmitri O.; Knight, Kevin S.; Johnston, Karen E.; Goff, Richard J.; Dolgikh, Valeriy A.; Lightfoot, Philip

2006-01-01

Several outstanding aspects of phase behaviour in the systems (Bi,Ln) 2 WO 6 and (Bi,Ln) 2 MoO 6 (Ln=lanthanide) have been clarified. Detailed crystal structures, from Rietveld refinement of powder neutron diffraction data, are provided for Bi 1.8 La 0.2 WO 6 (L-Bi 2 WO 6 type) and BiLaWO 6 , BiNdWO 6 , Bi 0.7 Yb 1.3 WO 6 and Bi 0.7 Yb 1.3 WO 6 (all H-Bi 2 WO 6 type). Phase evolution within the solid solution Bi 2- x La x MoO 6 has been re-examined, and a crossover from γ(H)-Bi 2 MoO 6 type to γ-R 2 MoO 6 type is observed at x∼1.2. A preliminary X-ray Rietveld refinement of the line phase BiNdMoO 6 has confirmed the α-R 2 MoO 6 type structure, with a possible partial ordering of Bi/Nd over the three crystallographically distinct R sites. - Graphical abstract: A summary of phase relations in the lanthanide-doped bismuth tungstate and bismuth molybdate systems is presented, together with some additional structural data on several of these phases

Fuzzy Bi-level Decision-Making Techniques: A Survey

Directory of Open Access Journals (Sweden)

Guangquan Zhang

2016-04-01

Full Text Available Bi-level decision-making techniques aim to deal with decentralized management problems that feature interactive decision entities distributed throughout a bi-level hierarchy. A challenge in handling bi-level decision problems is that various uncertainties naturally appear in decision-making process. Significant efforts have been devoted that fuzzy set techniques can be used to effectively deal with uncertain issues in bi-level decision-making, known as fuzzy bi-level decision-making techniques, and researchers have successfully gained experience in this area. It is thus vital that an instructive review of current trends in this area should be conducted, not only of the theoretical research but also the practical developments. This paper systematically reviews up-to-date fuzzy bi-level decisionmaking techniques, including models, approaches, algorithms and systems. It also clusters related technique developments into four main categories: basic fuzzy bi-level decision-making, fuzzy bi-level decision-making with multiple optima, fuzzy random bi-level decision-making, and the applications of bi-level decision-making techniques in different domains. By providing state-of-the-art knowledge, this survey paper will directly support researchers and practitioners in their understanding of developments in theoretical research results and applications in relation to fuzzy bi-level decision-making techniques.

3D hierarchically porous Cu-BiOCl nanocomposite films: one-step electrochemical synthesis, structural characterization and nanomechanical and photoluminescent properties

Science.gov (United States)

Guerrero, Miguel; Pané, Salvador; Nelson, Bradley J.; Baró, Maria Dolors; Roldán, Mònica; Sort, Jordi; Pellicer, Eva

2013-11-01

Three-dimensional (3D) hierarchically porous composite Cu-BiOCl films have been prepared by a facile one-step galvanostatic electrodeposition process from acidic electrolytic solutions containing Cu(ii) and Bi(iii) chloride salts and Triton X-100. The films show spherical, micron-sized pores that spread over the whole film thickness. In turn, the pore walls are made of randomly packed BiOCl nanoplates that are assembled leaving micro-nanopore voids beneath. It is believed that Cu grows within the interstitial spaces between the hydrogen bubbles produced from the reduction of H+ ions. Then, the BiOCl sheets accommodate in the porous network defined by the Cu building blocks. The presence of Cu tends to enhance the mechanical stability of the composite material. The resulting porous Cu-BiOCl films exhibit homogeneous and stable-in-time photoluminescent response arising from the BiOCl component that spreads over the entire 3D porous structure, as demonstrated by confocal scanning laser microscopy. A broad-band emission covering the entire visible range, in the wavelength interval 450-750 nm, is obtained. The present work paves the way for the facile and controlled preparation of a new generation of photoluminescent membranes.Three-dimensional (3D) hierarchically porous composite Cu-BiOCl films have been prepared by a facile one-step galvanostatic electrodeposition process from acidic electrolytic solutions containing Cu(ii) and Bi(iii) chloride salts and Triton X-100. The films show spherical, micron-sized pores that spread over the whole film thickness. In turn, the pore walls are made of randomly packed BiOCl nanoplates that are assembled leaving micro-nanopore voids beneath. It is believed that Cu grows within the interstitial spaces between the hydrogen bubbles produced from the reduction of H+ ions. Then, the BiOCl sheets accommodate in the porous network defined by the Cu building blocks. The presence of Cu tends to enhance the mechanical stability of the

A plate-on-plate sandwiched Z-scheme heterojunction photocatalyst: BiOBr-Bi{sub 2}MoO{sub 6} with enhanced photocatalytic performance

Energy Technology Data Exchange (ETDEWEB)

Wang, Shengyao [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070 (China); Yang, Xianglong; Zhang, Xuehao; Ding, Xing; Yang, Zixin [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Dai, Ke [College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070 (China); Chen, Hao, E-mail: hchenhao@mail.hzau.edu.cn [College of Science, Huazhong Agricultural University, Wuhan 430070 (China); Key Laboratory of Environment Correlative Dietology, Ministry of Education, Wuhan 430070 (China)

2017-01-01

Highlights: • A visible light heterojunction photocatalyst of BiOBr-Bi{sub 2}MoO{sub 6} was simply synthesized. • Carriers transferred efficiently in sandwiched layers causing an enhance activity. • A possible direct Z-scheme charge transfer mechanism of BiOBr-Bi2MoO6 is proposed. - Abstract: In this study, a direct Z-scheme heterojunction BiOBr-Bi{sub 2}MoO{sub 6} with greatly enhanced visible light photocatalytic performance was fabricated via a two-step coprecipitation method. It was indicated that a plate-on-plate heterojunctions be present between BiOBr and Bi{sub 2}MoO{sub 6} through different characterization techniques including X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), UV–vis diffuse reflectance spectroscopy (DRS) and photoelectrochemical measurements. The crystal structure and morphology analysis revealed that the heterointerface in BiOBr-Bi{sub 2}MoO{sub 6} occurred mainly on the (001) facets of BiOBr and (001) facets of Bi{sub 2}MoO{sub 6}. The photocatalytic activity of the BiOBr-Bi{sub 2}MoO{sub 6} was investigated by degradation of RhB and about 66.7% total organic carbon (TOC) could be removed. Ciprofloxacin (CIP) was employed to rule out the photosensitization. It was implied that the higher activity of BiOBr-Bi{sub 2}MoO{sub 6} could be attribute to the strong redox ability in the Z-scheme system, which was subsequently confirmed by photoluminescence spectroscopy (PL) and active spices trapping experiments. This study provides a promising platform for Z-scheme heterojunction constructing and also sheds light on highly efficient visible-light-driven photocatalysts designing.

Enhanced photocatalytic activity of cadmium-doped Bi{sub 2}WO{sub 6} nanoparticles under simulated solar light

Energy Technology Data Exchange (ETDEWEB)

Song, Xu Chun, E-mail: songxuchunfj@163.com; Li, Wen Ting [Fujian Normal University, Department of Chemistry (China); Huang, Wan Zhen; Zhou, Huan [Zhejiang University of Technology, Research Center of Analysis and Measurement (China); Yin, Hao Yong [Hangzhou Dianzi University, Institute of Environmental Science and Engineering (China); Zheng, Yi Fan [Zhejiang University of Technology, Research Center of Analysis and Measurement (China)

2015-03-15

Novel cadmium-doped Bi{sub 2}WO{sub 6} nanoparticles with different Cd contents have been synthesized by a one-step route using ethylene glycol and water as solvents at 180 °C for 12 h. The as-synthesized samples were characterized in detailed by SEM, XRD, EDS, HRTEM, UV–Vis DRS, BET techniques, and so on. The results shown that with the increase of the Cd{sup 2+} addition, the crystal structure, lattice space, and absorption edge were not significantly changed and the calculated band gap value was 2.58 eV. However, the flower-like Bi{sub 2}WO{sub 6} sphere was gradually destroyed. Simultaneously, the surface area and photocurrent responses of the catalysts were greatly increased. Photocatalytic activity of the Cd-doped Bi{sub 2}WO{sub 6} samples was determined by monitoring the change of RhB concentration under simulated solar light. The results revealed that cadmium doping greatly improved the photocatalytic efficiency of Bi{sub 2}WO{sub 6}. The Bi{sub 2}WO{sub 6} sample with R{sub Cd} = 0.05 displayed the highest photocatalytic activity, and the degradation rate is about two times greater than pure Bi{sub 2}WO{sub 6}. Moreover, the Cd–Bi{sub 2}WO{sub 6} photocatalyst remained stable even after five consecutive cycles. A possible mechanism of photocatalytic activity enhancement on basis of the experimental results was proposed.

DIALIGN: multiple DNA and protein sequence alignment at BiBiServ.

OpenAIRE

Morgenstern, Burkhard

2004-01-01

DIALIGN is a widely used software tool for multiple DNA and protein sequence alignment. The program combines local and global alignment features and can therefore be applied to sequence data that cannot be correctly aligned by more traditional approaches. DIALIGN is available online through Bielefeld Bioinformatics Server (BiBiServ). The downloadable version of the program offers several new program features. To compare the output of different alignment programs, we developed the program AltA...

Ions irradiation on bi-layer coatings

Science.gov (United States)

Tessarolo, Enrico; Corso, Alain Jody; Böttger, Roman; Martucci, Alessandro; Pelizzo, Maria G.

2017-09-01

Future space missions will operate in very harsh and extreme environments. Optical and electronics components need to be optimized and qualified in view of such operational challenges. This work focuses on the effect of low alpha particles irradiation on coatings. Low energy He+ (4 keV and 16 keV) ions have been considered in order to simulate in laboratory the irradiation of solar wind (slow and fast components) alpha particles. Mono- and proper bi-layers coatings have been investigated. The experimental tests have been carried out changing doses as well as fluxes during the irradiation sessions. Optical characterization in the UV-VIS spectral range and superficial morphological analysis have performed prior and after irradiation.

On Bi-Dimensional Second µ-Variation

Directory of Open Access Journals (Sweden)

Ereú Jurancy

2014-12-01

Full Text Available In this paper, we present a generalization of the notion of bounded slope variation for functions defined on a rectangle Iba in ℝ2. Given a strictly increasing function µ-defined in a closed real interval, we introduce the class BVµ,2 (Iba , of functions of bounded second µ-variation on Iba ; and show that this class can be equipped with a norm with respect to which it is a Banach space. We also deal with the important case of factorizable functions in BVµ,2 (Iba and finally we exhibit a relation between this class and the one of double Riemann-Stieltjes integrals of functions of bi-dimensional bounded variation.

Adjustable Two-Tier Cache for IPTV Based on Segmented Streaming

Directory of Open Access Journals (Sweden)

Kai-Chun Liang

2012-01-01

Full Text Available Internet protocol TV (IPTV is a promising Internet killer application, which integrates video, voice, and data onto a single IP network, and offers viewers an innovative set of choices and control over their TV content. To provide high-quality IPTV services, an effective strategy is based on caching. This work proposes a segment-based two-tier caching approach, which divides each video into multiple segments to be cached. This approach also partitions the cache space into two layers, where the first layer mainly caches to-be-played segments and the second layer saves possibly played segments. As the segment access becomes frequent, the proposed approach enlarges the first layer and reduces the second layer, and vice versa. Because requested segments may not be accessed frequently, this work further designs an admission control mechanism to determine whether an incoming segment should be cached or not. The cache architecture takes forward/stop playback into account and may replace the unused segments under the interrupted playback. Finally, we conduct comprehensive simulation experiments to evaluate the performance of the proposed approach. The results show that our approach can yield higher hit ratio than previous work under various environmental parameters.

Segmental osteotomies of the maxilla.

Science.gov (United States)

Rosen, H M

1989-10-01

Multiple segment Le Fort I osteotomies provide the maxillofacial surgeon with the capabilities to treat complex dentofacial deformities existing in all three planes of space. Sagittal, vertical, and transverse maxillomandibular discrepancies as well as three-dimensional abnormalities within the maxillary arch can be corrected simultaneously. Accordingly, optimal aesthetic enhancement of the facial skeleton and a functional, healthy occlusion can be realized. What may be perceived as elaborate treatment plans are in reality conservative in terms of osseous stability and treatment time required. The close cooperation of an orthodontist well-versed in segmental orthodontics and orthognathic surgery is critical to the success of such surgery. With close attention to surgical detail, the complication rate inherent in such surgery can be minimized and the treatment goals achieved in a timely and predictable fashion.

Stability of the anterior maxillary segment and teeth after segmental le fort I osteotomy and postoperative skeletal elastic fixation with or without occlusal splint.

Science.gov (United States)

Blæhr, Tue Lindberg; Jensen, Thomas; Due, Karen Margrethe; Neumann-Jensen, Bjarne

2014-07-01

To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. 29 consecutive patients underwent segmental Le Fort I osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A) or dismounted perioperatively (group B). Changes in landmarks and reference planes between the two timepoints were estimated on lateral cephalometric radiographs. The upper incisor had a mean intrusion of -0.56 mm (SD 0.77; range -2.04 to 1.08 mm) and a mean posterior movement of -0.93 mm (SD 1.03; range -2.52 to 0.96 mm). The mean change in the axial inclination of the upper incisor was -0.33° (SD 2.56; range -6° to 4°) (95% CI: -1.75 to 1.08°). Group B: The upper incisor had a mean intrusion of -0.13 mm (SD 1.36; range -1.92 to 3.6 mm) and a mean anterior movement of 0.11 mm (SD 1.78; range -2.88 to 3.84 mm). The mean change in the axial inclination of the upper incisor was -0.07° (SD 3.05; range -5° to 5°) (95% CI: -1.83 to 1.69°). There was no statistically significant difference in stability between the two groups at the P value 0.05. The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment in segmental Le Fort I osteotomy.

Stability of the Anterior Maxillary Segment and Teeth after Segmental Le Fort I Osteotomy and Postoperative Skeletal Elastic Fixation With or Without Occlusal Splint

Directory of Open Access Journals (Sweden)

Tue Lindberg

2014-10-01

Full Text Available Objectives: To assess the short term dental and skeletal stability of the anterior maxillary segment after segmental Le Fort I osteotomy with postoperative skeletal elastic fixation with or without occlusal splint. Material and Methods: 29 consecutive patients underwent segmental Le Fort I osteotomy and elastic skeletal fixation was applied. Patients were divided into two groups according to whether a fixed occlusal splint was used for six weeks (group A or dismounted perioperatively (group B. Changes in landmarks and reference planes between the two timepoints were estimated on lateral cephalometric radiographs. Results: Group A: The upper incisor had a mean intrusion of -0.56 mm (SD 0.77; range -2.04 to 1.08 mm and a mean posterior movement of -0.93 mm (SD 1.03; range -2.52 to 0.96 mm. The mean change in the axial inclination of the upper incisor was -0.33° (SD 2.56; range -6° to 4° (95% CI: -1.75 to 1.08°. Group B: The upper incisor had a mean intrusion of -0.13 mm (SD 1.36; range -1.92 to 3.6 mm and a mean anterior movement of 0.11 mm (SD 1.78; range -2.88 to 3.84 mm. The mean change in the axial inclination of the upper incisor was -0.07° (SD 3.05; range -5° to 5° (95% CI: -1.83 to 1.69°. There was no statistically significant difference in stability between the two groups at the P value 0.05. Conclusions: The skeletal anterior fixation with postoperative elastics for eight weeks may not compromise the early postoperative dental and skeletal stability of the anterior segment in segmental Le Fort I osteotomy.

[The Support System for Diabetic Patients at Home with Bi-Directional IT Communication].

Science.gov (United States)

Kubota, Masakazu; Hosoda, Kiminori; Eguchi, Kyoko; Nishijima, Yuki; Nakao, Kazuwa; Kinoshita, Ayae

2010-12-01

The present study analyzed the effects of bi-directional IT communication on the purpose of preventing diabetes progression and to reduce a caregiver burden. Diabetic patients were informed of the nature and purpose of the study before giving their voluntary consents to participate in the study. For the period of 12 weeks, a diabetic patient and his caregiver were communicated with a nurse through the TV telephone for 30 minutes once a week. Medical staff checked the list of weight change, compliance check, exercise habit, and attached pictures of the plate with a diabetic patient through the TV telephone in real time. We encouraged a diabetic patient to eat properly based on the diet record. The 12-week TV telephone communication resulted in the body weight decrease and HbA1c. There was a consciousness change about their daily eating habit. In the present study, the 12-week TV telephone communication once a week might be useful as an auxiliary therapy for changing a bad daily habit to a good daily habit for a diabetic patient at home.

Labview Implementation of Image Processing and Phasing Control for the SIBOA Segmented Mirror Testbed

Science.gov (United States)

Partridge, James D.

2002-01-01

'NASA is preparing to launch the Next Generation Space Telescope (NGST). This telescope will be larger than the Hubble Space Telescope, be launched on an Atlas missile rather than the Space Shuttle, have a segmented primary mirror, and be placed in a higher orbit. All these differences pose significant challenges.' This effort addresses the challenge of implementing an algorithm for aligning the segments of the primary mirror during the initial deployment that was designed by Philip Olivier and members of SOMTC (Space Optics Manufacturing Technology Center). The implementation was to be performed on the SIBOA (Systematic Image Based Optical Alignment) test bed. Unfortunately, hardware/software aspect concerning SIBOA and an extended time period for algorithm development prevented testing before the end of the study period. Properties of the digital camera were studied and understood, resulting in the current ability of selecting optimal settings regarding saturation. The study was successful in manually capturing several images of two stacked segments with various relative phases. These images can be used to calibrate the algorithm for future implementation. Currently the system is ready for testing.

Current distribution and enhancement of the engineering critical current density in multifilament Bi-2223 tapes

DEFF Research Database (Denmark)

Wang, W.G.; Jensen, M.B.; Kindl, B.

2000-01-01

The spatial distribution of the critical current density (Jc) and engineering critical current density (Je) along the tape width direction was studied by a cutting technique on Bi-2223 multifilamentary tapes. In general, an increase of Jc towards the centre of the tape was measured. We attribute...... microstructure with a great amount of secondary phases. Local variation of Jc was measured within the centre segment of the tape. This indicates the influence of other factors on Jc, such as filament shape, connectivity of the filaments, and sausaging. Enhancement of Je has been pursued in which average Je of 12...

The pinwheel pupil discovery: exoplanet science & improved processing with segmented telescopes

Science.gov (United States)

Breckinridge, James Bernard

2018-01-01

In this paper, we show that by using a “pinwheel” architecture for the segmented primary mirror and curved supports for the secondary mirror, we can achieve a near uniform diffraction background in ground and space large telescope systems needed for high SNR exoplanet science. Also, the point spread function will be nearly rotationally symmetric, enabling improved digital image reconstruction. Large (>4-m) aperture space telescopes are needed to characterize terrestrial exoplanets by direct imaging coronagraphy. Launch vehicle volume constrains these apertures are segmented and deployed in space to form a large mirror aperture that is masked by the gaps between the hexagonal segments and the shadows of the secondary support system. These gaps and shadows over the pupil result in an image plane point spread function that has bright spikes, which may mask or obscure exoplanets.These telescope artifact mask faint exoplanets, making it necessary for the spacecraft to make a roll about the boresight and integrate again to make sure no planets are missed. This increases integration time, and requires expensive space-craft resources to do bore-sight roll.Currently the LUVOIR and HabEx studies have several significant efforts to develop special purpose A/O technology and to place complex absorbing apodizers over their Hex pupils to shape the unwanted diffracted light. These strong apodizers absorb light, decreasing system transmittance and reducing SNR. Implementing curved pupil obscurations will eliminate the need for the highly absorbing apodizers and thus result in higher SNR.Quantitative analysis of diffraction patterns that use the pinwheel architecture are compared to straight hex-segment edges with a straight-line secondary shadow mask to show a gain of over a factor of 100 by reducing the background. For the first-time astronomers are able to control and minimize image plane diffraction background “noise”. This technology will enable 10-m segmented

Calorimetric investigation of Pb-Bi system

International Nuclear Information System (INIS)

Agarwal, Renu; Jat, Ram Avtar; Sen, B.K.

2008-01-01

Enthalpy increment of Pb 0.71 Bi 0.29 compound was determined using high temperature Calvet calorimeter. The data was fit into the following polynomial equation. ΔH(T-298.15 K) J/mol = -10384.96 + 39.23 T - 0.014T 2 - 18970/T. By precipitation method, the enthalpy of formation of the compound of composition Pb 0.68 Bi 0.32 at 448 K, from Pb(l) and Bi(l) was determined to be -2450± 50 J/mol and from Pb(s) and Bi(s) at 298.15 K was calculated to be 4047 J/mol. (author)

10^3 Segment MEMS Deformable-Mirror Process Development, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Iris AO will extend its proven segmented MEMS deformable mirror architecture to large array sizes required for high-contrast astrophysical imagers. Current...

Automated 3D closed surface segmentation: application to vertebral body segmentation in CT images.

Science.gov (United States)

Liu, Shuang; Xie, Yiting; Reeves, Anthony P

2016-05-01

A fully automated segmentation algorithm, progressive surface resolution (PSR), is presented in this paper to determine the closed surface of approximately convex blob-like structures that are common in biomedical imaging. The PSR algorithm was applied to the cortical surface segmentation of 460 vertebral bodies on 46 low-dose chest CT images, which can be potentially used for automated bone mineral density measurement and compression fracture detection. The target surface is realized by a closed triangular mesh, which thereby guarantees the enclosure. The surface vertices of the triangular mesh representation are constrained along radial trajectories that are uniformly distributed in 3D angle space. The segmentation is accomplished by determining for each radial trajectory the location of its intersection with the target surface. The surface is first initialized based on an input high confidence boundary image and then resolved progressively based on a dynamic attraction map in an order of decreasing degree of evidence regarding the target surface location. For the visual evaluation, the algorithm achieved acceptable segmentation for 99.35 % vertebral bodies. Quantitative evaluation was performed on 46 vertebral bodies and achieved overall mean Dice coefficient of 0.939 (with max [Formula: see text] 0.957, min [Formula: see text] 0.906 and standard deviation [Formula: see text] 0.011) using manual annotations as the ground truth. Both visual and quantitative evaluations demonstrate encouraging performance of the PSR algorithm. This novel surface resolution strategy provides uniform angular resolution for the segmented surface with computation complexity and runtime that are linearly constrained by the total number of vertices of the triangular mesh representation.

X-ray standing wave study of the Bi/GaAs and Bi/GaP interfaces

International Nuclear Information System (INIS)

Herrera-Gomez, A.

1994-04-01

Interfaces are one of the most important elements determining the characteristics of electronic devices. Composite semiconductors, specifically the III-V family, are technologically attractive because of their mobility and optical properties, and also because they offer the possibility of engineering such properties as the size of the band gap. Nevertheless, Si has remained the most utilized semiconductor material, primarily because the fabrication of practical MOSFETs with III-V semiconductors remains elusive. Examples of such complex interfaces are the structures formed by one monolayer of Bi on the (110) surface of GaAs and GaP. While better matched Column V elements form epitaxial continuous monolayers on III-V semiconductor (110) surfaces, Bi is too large to accommodate on GaAs and GaP surfaces with long range order, and vacancies appear to allow relaxation. For the ideal systems, symmetry imposes the presence of only two nonequivalent adatom sites. However, for Bi/GaAs and Bi/GaP, more than two different sites are present because the position of Bi atoms next to a vacancy is not necessarily equivalent to that between other Bi atoms. The geometry of the Bi/GaAs and Bi/GaP systems was determined here by triangulating XSW results from three Bragg planes. A methodology was developed that provides an intrinsic check of the validity of assuming two sites for the overlayer structures. An experimental method was developed that allows the three reflections to be measured on the same sample, thus reducing the number of experimental variables, such as the degree of disorder. The traditional method of analysis was not accurate enough for this data, so a more reliable and faster method of data fitting was developed. A configuration used in the present work, which previously has been widely used, presents an intrinsic multireflection problem. This issue is discussed in depth, and the appropriate method is determined for analyzing the data obtained with this configuration

Photocatalytic performances of BiFeO3 particles with the average size in nanometer, submicrometer, and micrometer

International Nuclear Information System (INIS)

Hao, Chunxue; FushengWen,; Xiang, Jianyong; Hou, Hang; Lv, Weiming; Lv, Yifei; Hu, Wentao; Liu, Zhongyuan

2014-01-01

Highlights: • Three different synthesis routes have been taken to successfully prepare the BiFeO 3 particles with the different morphologies and average size in 50, 500 nm, and 15 μm. • For photodegradation of dyes under visible irradiation in the presence of BiFeO 3 , the photocatalytic efficiency increases quickly with the decrease in size. • The enhanced photocatalytic efficiency of BiFeO 3 nanoparticles may attribute to more surface active catalytic-sites and shorter distances carriers have to migrate to the surface reaction sites. - Abstract: Three different synthesis routes were taken to successfully prepare the BiFeO 3 particles with the different morphologies and average size in 50, 500 nm, and 15 μm, respectively. The crystal structure was recognized to be a distorted rhombohedral one with the space group R3c. With the decrease in particle size, obvious decrease in peak intensity and redshift in peak position were observed for the Raman active bands. The narrow band gap was determined from the UV–vis absorption spectra, indicating the semiconducting nature of the BiFeO 3 . For photodegradation of dyes under visible irradiation in the presence of BiFeO 3 , the photocatalytic efficiency increased quickly with the decrease in size which may attribute to more surface active catalytic-sites and shorter distances carriers had to migrate to the surface reaction sites

Comparison of manual and automatic segmentation methods for brain structures in the presence of space-occupying lesions: a multi-expert study

International Nuclear Information System (INIS)

Deeley, M A; Cmelak, A J; Malcolm, A W; Moretti, L; Jaboin, J; Niermann, K; Yang, Eddy S; Yu, David S; Ding, G X; Chen, A; Datteri, R; Noble, J H; Dawant, B M; Donnelly, E F; Yei, F; Koyama, T

2011-01-01

The purpose of this work was to characterize expert variation in segmentation of intracranial structures pertinent to radiation therapy, and to assess a registration-driven atlas-based segmentation algorithm in that context. Eight experts were recruited to segment the brainstem, optic chiasm, optic nerves, and eyes, of 20 patients who underwent therapy for large space-occupying tumors. Performance variability was assessed through three geometric measures: volume, Dice similarity coefficient, and Euclidean distance. In addition, two simulated ground truth segmentations were calculated via the simultaneous truth and performance level estimation algorithm and a novel application of probability maps. The experts and automatic system were found to generate structures of similar volume, though the experts exhibited higher variation with respect to tubular structures. No difference was found between the mean Dice similarity coefficient (DSC) of the automatic and expert delineations as a group at a 5% significance level over all cases and organs. The larger structures of the brainstem and eyes exhibited mean DSC of approximately 0.8-0.9, whereas the tubular chiasm and nerves were lower, approximately 0.4-0.5. Similarly low DSCs have been reported previously without the context of several experts and patient volumes. This study, however, provides evidence that experts are similarly challenged. The average maximum distances (maximum inside, maximum outside) from a simulated ground truth ranged from (-4.3, +5.4) mm for the automatic system to (-3.9, +7.5) mm for the experts considered as a group. Over all the structures in a rank of true positive rates at a 2 mm threshold from the simulated ground truth, the automatic system ranked second of the nine raters. This work underscores the need for large scale studies utilizing statistically robust numbers of patients and experts in evaluating quality of automatic algorithms.

Improved Large Segmented Optics Fabrication Using Magnetorheological Finishing, Phase II

Data.gov (United States)

National Aeronautics and Space Administration — Primary mirrors for large aperture telescopes (> 10 m) are collections of smaller (1-2 m), typically hexagonal, often aspheric, optical segments. NASA's next...

ACM-based automatic liver segmentation from 3-D CT images by combining multiple atlases and improved mean-shift techniques.

Science.gov (United States)

Ji, Hongwei; He, Jiangping; Yang, Xin; Deklerck, Rudi; Cornelis, Jan

2013-05-01

In this paper, we present an autocontext model(ACM)-based automatic liver segmentation algorithm, which combines ACM, multiatlases, and mean-shift techniques to segment liver from 3-D CT images. Our algorithm is a learning-based method and can be divided into two stages. At the first stage, i.e., the training stage, ACM is performed to learn a sequence of classifiers in each atlas space (based on each atlas and other aligned atlases). With the use of multiple atlases, multiple sequences of ACM-based classifiers are obtained. At the second stage, i.e., the segmentation stage, the test image will be segmented in each atlas space by applying each sequence of ACM-based classifiers. The final segmentation result will be obtained by fusing segmentation results from all atlas spaces via a multiclassifier fusion technique. Specially, in order to speed up segmentation, given a test image, we first use an improved mean-shift algorithm to perform over-segmentation and then implement the region-based image labeling instead of the original inefficient pixel-based image labeling. The proposed method is evaluated on the datasets of MICCAI 2007 liver segmentation challenge. The experimental results show that the average volume overlap error and the average surface distance achieved by our method are 8.3% and 1.5 m, respectively, which are comparable to the results reported in the existing state-of-the-art work on liver segmentation.

Quantum interference effects in [Co/Bi]n thin films

Directory of Open Access Journals (Sweden)

Athanasopoulos P.

2014-07-01

Full Text Available Magnetoconductivity (MC, Δσ(Β, and Hall coefficient, RH(B, measurements have been performed in polycrystalline thin films of Bi(15nm, Bi(10nm/Co(1nm/Bi(10nm trilayer and [Co(0.7nm/Bi(2nm]10 multilayer, grown by magnetron scattering. The temperature dependence of RH(B curves reveal the existence of a second conduction channel below 250K, that can be assigned to surface states. MC measurements between ±0.4T show at 5K an interplay between weak-antilocalization (WAL in Bi and Bi/Co/Bi films and weal-localization (WL in [Co/Bi]10 multilayer.

Attempting to realize n-type BiCuSeO

Science.gov (United States)

Zhang, Xiaoxuan; Feng, Dan; He, Jiaqing; Zhao, Li-Dong

2018-02-01

As an intrinsic p-type semiconductor, BiCuSeO has been widely researched in the thermoelectric community, however, n-type BiCuSeO has not been reported so far. In this work, we successfully realized n-type BiCuSeO through carrying out several successive efforts. Seebeck coefficient of BiCuSeO was increased through introducing extra Bi/Cu to fill the Bi/Cu vacancies that may produce holes, and the maximum Seebeck coefficient was increase from +447 μVK-1 for undoped BiCuSeO to +638 μVK-1 for Bi1.04Cu1.05SeO. The Seebeck coefficient of Bi1.04Cu1.05SeO was changed from p-type to n-type through electron doping through introducing Br/I in Se sites, the maximum negative Seebeck coefficient can reach ∼ -465 μVK-1 and -543 μVK-1 for Bi1.04Cu1.05Se1-xIxO and Bi1.04Cu1.05Se1-xBrxO, respectively. Then, after compositing Bi1.04Cu1.05Se0.99Br0.01O with Ag, n-type BiCuSeO can be absolutely obtained in the whole temperature range of 300-873 K, the maximum ZT 0.05 was achieved at 475 K in the Bi1.04Cu1.05Se0.99Br0.01O+15% Ag. Our report indicates that it is possible to realize n-type conducting behaviors in BiCuSeO system.

Is Preventative Long-Segment Surgery for Multi-Level Spondylolysis Necessary? A Finite Element Analysis Study.

Directory of Open Access Journals (Sweden)

Jianqiang Mo

Full Text Available For multi-level spondylolysis patients, surgeons commonly choose to fix all the segments with pars interarticularis defect even those without slippage and not responsible for clinical symptoms. In this study, we tried to study the necessity of the preventative long-segment surgery for the defected segment without slippage in treatment of multi-level spondylolysis patients from a biomechanical perspective.We established a bi-level spondylolysis model with pars defects at L4 and L5 segments, and simulated posterior lumbar interbody fusion (PLIF and pedicle screw fixation at L5-S1 level. Then we compared the biomechanical changes at L4 segment before and after surgery in neutral, flexion, extension, lateral bending and axial rotation position.The stress on L4 pars interarticularis was very similar before and after surgery, and reached the highest in axial rotation. The L3-L4 intradiscal pressure was almost the same, while L4-L5 intradiscal pressure changed a little in lateral bending (increase from 1.993 to 2.160 MPa and axial rotation (decrease from 1.639 to 1.307 MPa after surgery. The PLIF surgery caused a little increase of range of motion at adjacent L4-L5 and L3-L4 levels, but the change is very tiny (1 degree.The PLIF surgery will not cause significant biomechanical change at adjacent segment with pars defect in multi-level spondylolysis. On the contrary, excessive long-segment surgery will damage surrounding soft tissues which are important for maintaining the stability of spine. So a preventative long-segment surgery is not necessary for multi-level spondylolysis as long as there are no soft tissue degeneration signs at adjacent level.

Is Preventative Long-Segment Surgery for Multi-Level Spondylolysis Necessary? A Finite Element Analysis Study.

Science.gov (United States)

Mo, Jianqiang; Zhang, Wen; Zhong, Dongyan; Xu, Hao; Wang, Lan; Yu, Jia; Luo, Zongping

2016-01-01

For multi-level spondylolysis patients, surgeons commonly choose to fix all the segments with pars interarticularis defect even those without slippage and not responsible for clinical symptoms. In this study, we tried to study the necessity of the preventative long-segment surgery for the defected segment without slippage in treatment of multi-level spondylolysis patients from a biomechanical perspective. We established a bi-level spondylolysis model with pars defects at L4 and L5 segments, and simulated posterior lumbar interbody fusion (PLIF) and pedicle screw fixation at L5-S1 level. Then we compared the biomechanical changes at L4 segment before and after surgery in neutral, flexion, extension, lateral bending and axial rotation position. The stress on L4 pars interarticularis was very similar before and after surgery, and reached the highest in axial rotation. The L3-L4 intradiscal pressure was almost the same, while L4-L5 intradiscal pressure changed a little in lateral bending (increase from 1.993 to 2.160 MPa) and axial rotation (decrease from 1.639 to 1.307 MPa) after surgery. The PLIF surgery caused a little increase of range of motion at adjacent L4-L5 and L3-L4 levels, but the change is very tiny (1 degree). The PLIF surgery will not cause significant biomechanical change at adjacent segment with pars defect in multi-level spondylolysis. On the contrary, excessive long-segment surgery will damage surrounding soft tissues which are important for maintaining the stability of spine. So a preventative long-segment surgery is not necessary for multi-level spondylolysis as long as there are no soft tissue degeneration signs at adjacent level.

Electron microscopy analyses and electrical properties of the layered Bi2WO6 phase

International Nuclear Information System (INIS)

Taoufyq, A.; Ait Ahsaine, H.; Patout, L.; Benlhachemi, A.; Ezahri, M.

2013-01-01

The bismuth tungstate Bi 2 WO 6 was synthesized using a classical coprecipitation method followed by a calcination process at different temperatures. The samples were characterized by X-ray diffraction, simultaneous thermogravimetry and differential thermal analysis (TGA/DTA), scanning and transmission electron microscopy (SEM, TEM) analyses. The Rietveld analysis and electron diffraction clearly confirmed the Pca2 1 non centrosymmetric space group previously proposed for this phase. The layers Bi 2 O 2 2+ and WO 4 2− have been directly evidenced from the HRTEM images. The electrical properties of Bi 2 WO 6 compacted pellets systems were determined from electrical impedance spectrometry (EIS) and direct current (DC) analyses, under air and argon, between 350 and 700 °C. The direct current analyses showed that the conduction observed from EIS analyses was mainly ionic in this temperature range, with a small electronic contribution. Electrical change above the transition temperature of 660 °C is observed under air and argon atmospheres. The strong conductivity increase observed under argon is interpreted in terms of formation of additional oxygen vacancies coupled with electron conduction. - Graphical abstract: High resolution transmission electron microscopy: inverse fast Fourier transform giving the layered structure of the Bi 2 WO 6 phase, with a representation of the cell dimensions (b and c vectors). The Bi 2 O 2 2+ and WO 4 2− sandwiches are visible in the IFFT image. - Highlights: • Using transmission electron microscopy, we visualize the layered structure of Bi 2 WO 6 . • Electrical analyses under argon gas show some increase in conductivity. • The phase transition at 660 °C is evidenced from electrical modification

Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2): New one-dimensional Bi-coordination materials—Reversible hydration and topotactic decomposition to α-Bi2O3

International Nuclear Information System (INIS)

Jeon, Hye Rim; Lee, Dong Woo; Ok, Kang Min

2012-01-01

Two one-dimensional bismuth-coordination materials, Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 ) x F (x=1 and 2), have been synthesized by hydrothermal reactions using Bi 2 O 3 , 2,6-NC 5 H 3 (CO 2 H) 2 , HF, and water at 180 °C. Structures of the two materials were determined by single-crystal X-ray diffraction. Although they have different crystal structures, both Bi-organic materials shared a common structural motif, a one-dimensional chain structure consisting of Bi 3+ cations and pyridine dicarboxylate linkers. Detailed structural analyses include infrared spectroscopy, thermogravimetric analysis, and reversible hydration reactions for the coordinated water molecules were reported. Also, thermal decomposition of the rod-shaped Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F single crystals at 800 °C led to α-Bi 2 O 3 that maintained the same morphology of the original crystals. - Graphical abstract: Calcination of the Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F single crystals at 800 °C results in the α-Bi 2 O 3 rods that maintain the original morphology of the crystals. Highlights: ► Synthesis of one-dimensional chain Bi-organic frameworks. ► Reversible hydration reactions of Bi[NC 5 H 3 (CO 2 ) 2 ](OH 2 )F. ► Topotactic decomposition maintaining the same morphology of the original crystals.

Status of the segment interconnect, cable segment ancillary logic, and the cable segment hybrid driver projects

International Nuclear Information System (INIS)

Swoboda, C.; Barsotti, E.; Chappa, S.; Downing, R.; Goeransson, G.; Lensy, D.; Moore, G.; Rotolo, C.; Urish, J.

1985-01-01

The FASTBUS Segment Interconnect (SI) provides a communication path between two otherwise independent, asynchronous bus segments. In particular, the Segment Interconnect links a backplane crate segment to a cable segment. All standard FASTBUS address and data transactions can be passed through the SI or any number of SIs and segments in a path. Thus systems of arbitrary connection complexity can be formed, allowing simultaneous independent processing, yet still permitting devices associated with one segment to be accessed from others. The model S1 Segment Interconnect and the Cable Segment Ancillary Logic covered in this report comply with all the mandatory features stated in the FASTBUS specification document DOE/ER-0189. A block diagram of the SI is shown

Creating pedagogical spaces for developing doctor professional identity.

Science.gov (United States)

Clandinin, D Jean; Cave, Marie-Therese

2008-08-01

Working with doctors to develop their identities as technically skilled as well as caring, compassionate and ethical practitioners is a challenge in medical education. One way of resolving this derives from a narrative reflective practice approach to working with residents. We examine the use of such an approach. This paper draws on a 2006 study carried out with four family medicine residents into the potential of writing, sharing and inquiring into parallel charts in order to help develop doctor identity. Each resident wrote 10 parallel charts over 10 weeks. All residents met bi-weekly as a group with two researchers to narratively inquire into the stories told in their charts. One parallel chart and the ensuing group inquiry about the chart are described. In the narrative reflective practice process, one resident tells of working with a patient and, through writing, sharing and inquiry, integrates her practice and how she learned to be a doctor in one cultural setting into another cultural setting; another resident affirms her relational way of practising medicine, and a third resident begins to see the complexity of attending to patients' experiences. The process shows the importance of creating pedagogical spaces to allow doctors to tell and retell, through narrative inquiry, their stories of their experiences. This pedagogical approach creates spaces for doctors to individually develop their own stories by which to live as doctors through narrative reflection on their interwoven personal, professional and cultural stories as they are shaped by, and enacted within, their professional contexts.

Development of the WDS Russian-Ukrainian Segment

Directory of Open Access Journals (Sweden)

Marsel Shaimardanov

2013-01-01

Full Text Available Establishment of the Russian-Ukrainian WDS Segment and its state of the art, main priorities and research activities are described. One of the high priority tasks for Segment members is development of a common information space - transition from Legacy Systems and individual services to a common, globally interoperable, distributed data system that incorporates emerging technologies and new scientific data activities. The new system will build on the potential and added value offered by advanced interconnections between data management and data processing components for disciplinary and multidisciplinary applications. Thus, the principles of the architectural organization of intelligent data processing systems are discussed in this paper.

Pleural effusion segmentation in thin-slice CT

Science.gov (United States)

Donohue, Rory; Shearer, Andrew; Bruzzi, John; Khosa, Huma

2009-02-01

A pleural effusion is excess fluid that collects in the pleural cavity, the fluid-filled space that surrounds the lungs. Surplus amounts of such fluid can impair breathing by limiting the expansion of the lungs during inhalation. Measuring the fluid volume is indicative of the effectiveness of any treatment but, due to the similarity to surround regions, fragments of collapsed lung present and topological changes; accurate quantification of the effusion volume is a difficult imaging problem. A novel code is presented which performs conditional region growth to accurately segment the effusion shape across a dataset. We demonstrate the applicability of our technique in the segmentation of pleural effusion and pulmonary masses.

Comparison of Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor thin films fabricated by the spin coating and radio frequency magnetron techniques

Energy Technology Data Exchange (ETDEWEB)

Jafer, R.M.; Yousif, A. [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Department of Physics, Faculty of Education, University of Khartoum, P.O. Box 321, Postal Code 11115 Omdurman (Sudan); Kumar, Vinod [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Photovoltaic Laboratory, Centre for Energy Studies, Indian Institute of Technology Delhi, New Delhi 110016 (India); Pathak, Trilok Kumar [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Semiconductor Physics Lab, Department of Physics, Gurukula Kangri University, Haridwar (India); Purohit, L.P. [Semiconductor Physics Lab, Department of Physics, Gurukula Kangri University, Haridwar (India); Swart, H.C., E-mail: swarthc@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa); Coetsee, E., E-mail: CoetseeE@ufs.ac.za [Department of Physics, University of the Free State, P.O. Box 339, Bloemfontein ZA 9300 (South Africa)

2016-09-15

The reactive radio-frequency (RF) magnetron sputtering and spin coating fabrication techniques were used to fabricate Y{sub 2−x}O{sub 3}:Bi{sub x=0.5%} phosphor thin films. The two techniques were analysed and compared as part of investigations being done on the application of down-conversion materials for a Si solar cell. The morphology, structural and optical properties of these thin films were investigated. The X-ray diffraction results of the thin films fabricated by both techniques showed cubic structures with different space groups. The optical properties showed different results because the Bi{sup 3+} ion is very sensitive towards its environment. The luminescence results for the thin film fabricated by the spin coating technique is very similar to the luminescence observed in the powder form. It showed three obvious emission bands in the blue and green regions centered at about 360, 410 and 495 nm. These emissions were related to the {sup 3}P{sub 1}–{sup 1}S{sub 0} transition of the Bi{sup 3+} ion situated in the two different sites of the Y{sub 2}O{sub 3} matrix with I a-3(206) space group. Whereas the thin film fabricated by the radio frequency magnetron technique showed a broad single emission band in the blue region centered at about 416 nm. This was assigned to the {sup 3}P{sub 1}–{sup 1}S{sub 0} transition of the Bi{sup 3+} ion situated in one of the Y{sub 2}O{sub 3} matrix's sites with a Fm-3 (225) space group. The spin coating fabrication technique is suggested to be the best technique to fabricate the Y{sub 2}O{sub 3}:Bi{sup 3+} phosphor thin films. - Highlights: • RF sputtering and spin coating were used to fabricate Y{sub 2−x}O{sub 3}:Bi{sub x=0.5%} phosphor thin films. • XRD results of the two films showed cubic structures with different space groups. • PL showed different emission for the Bi{sup 3+} ions in the two films. • Three emission bands in the blue and green regions centered at about 360, 410 and 495 nm. • RF

Controlled hydrothermal synthesis of BiOxCly/BiOmIn composites exhibiting visible-light photocatalytic degradation of crystal violet

International Nuclear Information System (INIS)

Jiang, Yu-Rou; Lin, Ho-Pan; Chung, Wen-Hsin; Dai, Yong-Ming; Lin, Wan-Yu; Chen, Chiing-Chang

2015-01-01

Highlights: • This is the first report on a series of BiO x Cl y /BiO m I n heterojunctions. • The BiO x Cl y /BiO m I n composition was controlled by adjusting the growth parameters. • The BiO x Cl y /BiO m I n were indirect semiconductors with a 1.78–2.95-eV bandgap. • The new photocatalysts removed CV at a much faster rate than TiO 2 . • Mechanisms were determined by separating the intermediates using HPLC-MS. - Abstract: A series of BiO x Cl y /BiO m I n composites were prepared using autoclave hydrothermal methods. The composition and morphologies of the BiO x Cl y /BiO m I n composites were controlled by adjusting the experimental conditions: the reaction pH value, temperature, and KCl/KI molar ratio. The products were characterized using X-ray diffraction, scanning electron microscopy-electron dispersive X-ray spectroscopy, UV–vis diffuse reflectance spectroscopy, Brunauer–Emmett–Teller specific surface areas, cathodoluminescence, high-resolution transmission electron microscopy, and high-resolution X-ray photoelectron spectroscopy. The photocatalytic efficiencies of composite powder suspensions were evaluated by monitoring the crystal violet (CV) concentrations. In addition, the quenching effects of various scavengers indicated that the reactive O 2 · − played a major role, and OH· or h + played a minor role in CV degradation. The intermediates formed during the decomposition process were isolated, identified, and characterized using high performance liquid chromatography-photodiode array-electrospray ionization-mass spectrometry to elucidate the CV decomposition mechanism

Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

Science.gov (United States)

Zhang, Min; Wei, Zhan-Tao

2018-03-01

Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

Effect of Silver Doping on Transport Properties of Bi2Se3: AgxBi2Se3 and Bi2-xAgxSe3

Science.gov (United States)

Zhang, Min; Wei, Zhan-Tao

2018-05-01

Ag-doped Bi2Se3 with the formula AgxBi2Se3 and Bi2-xAgxSe3 were prepared and their electrical and magnetic transport properties have been investigated to study the influence of silver doping on transport properties of Bi2Se3 with different Ag-doped method. All samples exhibited metallic resistivity and the resistivity increased with increasing Ag concentration. The lattice parameter c of Ag-substituted and Ag-intercalated samples displays a contrary change as the Ag concentration increased. For the Ag-intercalated samples, both the resistance upturn were observed in the curves of temperature dependent of resistivity and temperature dependent of magnetoresistance, respectively, indicating that the enhanced surface effect was obtained in those samples. Monotonously, field-induced MR peaks around 200 K were also observed in those samples. Similar behaviors were not observed in the Ag-substituted samples.

Reduction in thermal conductivity of BiSbTe lump

Energy Technology Data Exchange (ETDEWEB)

Ahmad, Kaleem [King Saud University, Sustainable Energy Technologies Center, College of Engineering, PO Box 800, Riyadh (Saudi Arabia); Wan, C. [Tsinghua University, State Key Laboratory of New Ceramics and Fine Processing, School of Materials Science and Engineering, Beijing (China); Al-Eshaikh, M.A.; Kadachi, A.N. [King Saud University, Research Center, College of Engineering, PO Box 800, Riyadh (Saudi Arabia)

2017-03-15

In this work, systematic investigations on the thermal conductivities of BiSbTe lump, microstructured pristine BiSbTe bulk and single wall carbon nanotubes (SWCNTs)/BiSbTe bulk nanocomposites were performed. BiSbTe lumps were crushed to form a coarse powder (200 μm) and effect of particle size reduction on the effective thermal conductivity of BiSbTe (200 μm) bulk were analyzed. For further reduction in the conductivity, a two pronged strategy has been employed. First, additional refinement of BiSbTe (200 μm) were performed through ball milling in an inert environment. Second, SWCNTs in 0.75, and 1.0 vol% were distributed uniformly in the fine BiSbTe ball milled powder. The results showed that the effective thermal conductivities decrease with the reduction in the particle size from lump to BiSbTe (200 μm) bulk as well as with the addition of SWCNTs accompanied by further refinement of BiSbTe particles. The significant reduction in thermal conductivities of the lump was achieved for pure BiSbTe (200 μm) bulk and 0.75 vol% of SWCNTs/BiSbTe composite. This can be ascribed to the enhanced phonon scattering by the grain boundaries between the nanostructured BiSbTe particles as well as the interfaces between BiSbTe and the low dimensional carbon nanotubes. (orig.)

Synthesis, structure, and characterization of two new bismuth(III) selenite/tellurite nitrates: [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3})

Energy Technology Data Exchange (ETDEWEB)

Meng, Chang-Yu; Wei, Ming-Fang [Department of Chemistry and Materials, Yulin Normal University,Yulin, Guangxi 537000 (China); Geng, Lei, E-mail: lgeng.cn@gmail.com [Department of Materials Science and Engineering, Huaibei Normal University, Huaibei, Anhui 235000 (China); Hu, Pei-Qing; Yu, Meng-Xia [Department of Chemistry and Materials, Yulin Normal University,Yulin, Guangxi 537000 (China); Cheng, Wen-Dan [State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, Fuzhou, Fujian 350002 (China)

2016-07-15

Two new bismuth(III) selenite/tellurite nitrates, [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3}), have been synthesized by conventional facile hydrothermal method at middle temperature 200 °C and characterized by single-crystal X-ray diffraction, powder diffraction, UV–vis–NIR optical absorption spectrum, infrared spectrum and thermal analylsis. Both [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO3)](NO3) crystallize in the monoclinic centronsymmetric space group P2{sub 1}/c with a=9.9403(4) Å, b=9.6857(4) Å, c=10.6864(5) Å, β=93.1150(10)° for [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and a=8.1489(3) Å, b=9.0663(4) Å, c=7.4729(3) Å, β=114.899(2)° for Bi(TeO3)(NO3), respectively. The two compounds, whose structures are composed of three different asymmetric building units, exhibit two different types of structures. The structure of [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) features a three-dimensional (3D) bismuth(III) selenite cationic tunnel structure [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}] {sup 3}{sub ∞} with NO{sub 3}{sup −} anion group filling in the 1D tunnel along b axis. The structure of [Bi(TeO{sub 3})](NO{sub 3}) features 2D bismuth(III) tellurite [Bi(TeO{sub 3}){sub 2}]{sup 2}{sub ∞} layers separated by NO{sub 3}{sup −} anion groups. The results of optical diffuse-reflectance spectrum measurements and electronic structure calculations based on density functional theory methods show that the two compounds are wide band-gap semiconductors. - Graphical abstract: Two novel bismuth{sup III} selenite/tellurite nitrates [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) with 3D tunnel structure and [Bi(TeO{sub 3})](NO{sub 3}) with 2D layer structure have been firstly synthesized and characterized. Display Omitted - Highlights: • Two novel bismuth{sup III} nitrates [(Bi{sub 3}O{sub 2})(SeO{sub 3}){sub 2}](NO{sub 3}) and [Bi(TeO{sub 3})](NO{sub 3}) were firstly

Surgical Splint Design Influences Transverse Expansion in Segmental Maxillary Osteotomies

DEFF Research Database (Denmark)

Stokbro, Kasper; Aagaard, Esben; Torkov, Peter

2017-01-01

splint designs on achieving the planned transverse expansion in bimaxillary surgery with segmental maxillary procedures. Materials and Methods: Forty-two participants were included in a retrospective observational study. All participants had completed virtually planned bimaxillary surgery with 3-piece......Purpose: In segmental maxillary procedures, it is imperative to obtain as much of the planned expansion as possible. Lack of obtained expansion, in addition to late relapse after splint removal, can result in relapse of the posterior crossbite. This study investigated the influence of 2 surgical...... maxillary segmentation. The primary outcome variable was the transverse expansion obtained, measured as the expansion between the maxillary first molars on preoperative and postoperative cone-beam computed tomograms. The postoperative scan was performed 1 week after surgery with the splint still in place...

Preparation and Faraday rotation of Bi-YIG/PMMA nanocomposite

Science.gov (United States)

Fu, H. P.; Hong, R. Y.; Wu, Y. J.; Di, G. Q.; Xu, B.; Zheng, Y.; Wei, D. G.

Bismuth-substituted yttrium iron garnet (Bi-YIG) nanoparticles (NPs) were prepared by coprecipitation and subsequent heating treatment. Thermal gravity-differential thermal analysis was performed to investigate the thermal behavior of the Bi-YIG precursors and to decide the best annealing temperature. Phase formation of garnet NPs was investigated by X-ray powder diffraction. The size of Bi-YIG NPs was investigated by transmission electron microscopy, and the magnetic properties of Bi-YIG NPs were measured using a vibrating sample magnetometer. The results show that the temperature needed for the transformation of Bi-YIG from the amorphous phase to the garnet phase decreases with increasing Bi content, and Bi-YIG NPs with sizes of 28-78 nm are obtained after heating treatment at 650-1000 °C. The saturation magnetization of Bi-YIG NPs increases as the Bi content increases. Moreover, the Faraday rotation of polymethyl methacrylate (PMMA) slices doped with Bi-YIG NPs was investigated. The results indicate that the angle of Faraday rotation increases with increasing Bi content in PMMA composites, and the maximum value of the figure of merit is 1.46°, which is comparable to the value of a sputtered film. The Bi-YIG NPs-doped PMMA slices are new promising materials for magneto-optical devices.

Facile synthesis of AgI/BiOI-Bi{sub 2}O{sub 3} multi-heterojunctions with high visible light activity for Cr(VI) reduction

Energy Technology Data Exchange (ETDEWEB)

Wang, Qi [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); The Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Shi, Xiaodong; Liu, Enqin [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); Crittenden, John C. [The Brook Byer Institute for Sustainable Systems and School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta 30332 (United States); Ma, Xiangjuan; Zhang, Yi [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China); Cong, Yanqing, E-mail: yqcong@hotmail.com [School of Environmental Science and Engineering, Zhejiang Gongshang University, Hangzhou 310018 (China)

2016-11-05

Graphical abstract: Highly visible-light-active AgI/BiOI-Bi{sub 2}O{sub 3} with multi-heterojunctions was developed. - Highlights: • Visible-light-active AgI/BiOI-Bi{sub 2}O{sub 3} with multi-heterojunctions was prepared. • Highly enhanced photocatalytic reduction of Cr(VI) was observed. • k{sub Cr(VI)} on AgI/BiOI-Bi{sub 2}O{sub 3} increased by ca.16 times relative to Bi{sub 2}O{sub 3}. • Decreased E{sub g}, shifted E{sub fb} and reduced charge transfer resistance were observed. • Simultaneous reduction of Cr(VI) and degradation of organics were achieved. - Abstract: AgI sensitized BiOI-Bi{sub 2}O{sub 3} composite (AgI/BiOI-Bi{sub 2}O{sub 3}) with multi-heterojunctions was prepared using simple etching-deposition process. Different characterization techniques were performed to investigate the structural, optical and electrical properties of the as-prepared photocatalysts. It was found that the ternary AgI/BiOI-Bi{sub 2}O{sub 3} composite exhibited: (1) improved photocurrent response, (2) smaller band gap, (3) greatly reduced charge transfer resistance and (4) negative shift of flat band potential, which finally led to easier generation and more efficient separation of photo-generated electron-hole pairs at the hetero-interfaces. Thus, for the reduction of Cr(VI), AgI/BiOI-Bi{sub 2}O{sub 3} exhibited excellent photocatalytic activity under visible light irradiation at near neutral pH. AgI/BiOI-Bi{sub 2}O{sub 3} was optimized when the initial molar ratio of KI to Bi{sub 2}O{sub 3} and AgNO{sub 3} to Bi{sub 2}O{sub 3} was 1:1 and 10%, respectively. The estimated k{sub Cr(VI)} on optimized AgI/BiOI-Bi{sub 2}O{sub 3} was about 16 times that on pure Bi{sub 2}O{sub 3}. Good stability was also observed in cyclic runs, indicating that the current multi-heterostructured photocatalyst is highly desirable for the remediation of Cr(VI)-containing wastewater.

In situ grown hierarchical 50%BiOCl/BiOI hollow flowerlike microspheres on reduced graphene oxide nanosheets for enhanced visible-light photocatalytic degradation of rhodamine B

Science.gov (United States)

Su, Xiangde; Yang, Jinjin; Yu, Xiang; Zhu, Yi; Zhang, Yuanming

2018-03-01

50%BiOCl/BiOI/reduced graphene oxide (50%BiOCl/BiOI/rGO) composite photocatalyst was synthesized successfully by a facile one-step solvothermal route in this work. Reduction of graphene oxide (GO) took place in the process of solvothermal reaction and a new Bi-C bond between rGO and 50%BiOCl/BiOI was formed. The introduction of rGO affected the morphology of 50%BiOCl/BiOI, resulting in the transformation of 50%BiOCl/BiOI from solid microspheres to hollow microspheres. Both the introduction of rGO and formation of 50%BiOCl/BiOI hollow microspheres can facilitate the light absorption. The strong interaction between 50%BiOCl/BiOI and rGO and the electrical conductivity of rGO greatly improved the effective separation of photogenerated carriers. Hence, GOB-5 demonstrated the highest photocatalytic activity which was over twice of the pristine 50%BiOCl/BiOI in the presence of visible light. Mechanism study revealed that 50%BiOCl/BiOI generated electrons and holes in the presence of visible light, and holes together with rad O2- generated from reduction of O2 by electrons degraded the pollutant directly. Overall, this work provides an excellent reference to the synthesis of chemically bonded BiOX/BiOY (X, Y = Cl, Br, I)/rGO nanocomposite and helps to promote their applications in environmental protection and photoelectric conversion.

alpha-decay spectroscopy of light odd-odd Bi isotopes - II sup 1 sup 8 sup 6 Bi and the new nuclide sup 1 sup 8 sup 4 Bi

CERN Document Server

Andreyev, A N; Ackermann, D; Münzenberg, G; Hessberger, F P; Hofmann, S; Kojouharov, I; Kindler, B; Lommel, B; Huyse, M; Vel, K V D; Duppen, P V; Heyde, Kris L G

2003-01-01

Alpha-decay of the new nuclide sup 1 sup 8 sup 4 Bi has been studied in the complete-fusion reaction sup 9 sup 3 Nb( sup 9 sup 4 Mo, 3n) sup 1 sup 8 sup 4 Bi at the velocity filter SHIP. The evaporation residues were separated in-flight and subsequently identified on the basis of recoil-alpha, recoil-alpha-gamma analysis and excitation functions measurements. Two alpha-decaying isomeric states in sup 1 sup 8 sup 4 Bi with half-life values of 13(2) ms and 6.6(1.5) ms were identified. The alpha-branching ratio of sup 1 sup 8 sup 0 Tl was deduced for the first time as b subalpha = (2-12)%. Improved data on the fine-structure alpha-decay of sup 1 sup 8 sup 6 Bi were obtained in the sup 9 sup 3 Nb( sup 9 sup 5 Mo, 2n) sup 1 sup 8 sup 6 Bi reaction. A similarity of the decay energies and half-life values of sup 1 sup 8 sup 4 sup , sup 1 sup 8 sup 6 Bi is pointed out and a possible explanation for this effect is suggested.

Superstrengthening Bi2Te3 through Nanotwinning

Science.gov (United States)

Li, Guodong; Aydemir, Umut; Morozov, Sergey I.; Wood, Max; An, Qi; Zhai, Pengcheng; Zhang, Qingjie; Goddard, William A.; Snyder, G. Jeffrey

2017-08-01

Bismuth telluride (Bi2Te3 ) based thermoelectric (TE) materials have been commercialized successfully as solid-state power generators, but their low mechanical strength suggests that these materials may not be reliable for long-term use in TE devices. Here we use density functional theory to show that the ideal shear strength of Bi2Te3 can be significantly enhanced up to 215% by imposing nanoscale twins. We reveal that the origin of the low strength in single crystalline Bi2Te3 is the weak van der Waals interaction between the Te1 coupling two Te 1 - Bi - Te 2 - Bi - Te 1 five-layer quint substructures. However, we demonstrate here a surprising result that forming twin boundaries between the Te1 atoms of adjacent quints greatly strengthens the interaction between them, leading to a tripling of the ideal shear strength in nanotwinned Bi2Te3 (0.6 GPa) compared to that in the single crystalline material (0.19 GPa). This grain boundary engineering strategy opens a new pathway for designing robust Bi2Te3 TE semiconductors for high-performance TE devices.

The Origin of the Superstructure in Bi2Sr2CaCu2O8+dgr as Revealed by Scanning Tunneling Microscopy.

Science.gov (United States)

Kirk, M D; Nogami, J; Baski, A A; Mitzi, D B; Kapitulnik, A; Geballe, T H; Quate, C F

1988-12-23

Real-space images with atomic resolution of the BiO plane of Bi(2)Sr(2)CaCu(2)O(8+delta) were obtained with a scanning tunneling microscope. Single-crystal samples were cleaved and imaged under ultrahigh vacuum conditions at room temperature. The images clearly show the one-dimensional incommensurate superstructure along the b-axis that is common to this phase. High-resolution images show the position of the Bi atoms, revealing the structural nature of the superlattice. A missing row of Bi atoms occurs either every nine or ten atomic sites in both (110) directions, accounting for the measured incommensurate periodicity of the superstructure. A model is proposed that includes missing rows of atoms, as well as displacements of the atomic positions along both the a- and c-axis directions.

The origin of the superstructure in Bi2Sr2CaCu2O(8+delta) as revealed by scanning tunneling microscopy

Science.gov (United States)

Kirk, M. D.; Nogami, J.; Baski, A. A.; Mitzi, D. B.; Kapitulnik, A.

1988-12-01

Real-space images with atomic resolution of the BiO plane of Bi2Sr2CaCu2O(8+delta) were obtained with a scanning tunneling microscope. Single-crystal samples were cleaved and imaged under ultrahigh vacuum conditions at room temperature. The images clearly show the one-dimensional incommensurate superstructure along the b-axis that is common to this phase. High-resolution images show the position of the Bi atoms, revelaing the structural nature of the superlattice. A missing row of Bi atoms occurs either every nine or ten atomic sites in both 110-line directions, accounting for the measured incommensurate periodicity of the superstructure. A model is proposed that includes missing rows of atoms, as well as displacements of the atomic positions along both the a- and c-axis directions.

Comparison of growth texture in round Bi2212 and flat Bi2223 wires and its relation to high critical current density development

OpenAIRE

Kametani, F.; Jiang, J.; Matras, M.; Abraimov, D.; Hellstrom, E. E.; Larbalestier, D. C.

2015-01-01

Why Bi2Sr2CaCu2Ox (Bi2212) allows high critical current density Jc in round wires rather than only in the anisotropic tape form demanded by all other high temperature superconductors is important for future magnet applications. Here we compare the local texture of state-of-the-art Bi2212 and Bi2223 ((Bi,Pb)2Sr2Ca2Cu3O10), finding that round wire Bi2212 generates a dominant a-axis growth texture that also enforces a local biaxial texture (FWHM

Evaluation and comparison of current fetal ultrasound image segmentation methods for biometric measurements: a grand challenge.

Science.gov (United States)

Rueda, Sylvia; Fathima, Sana; Knight, Caroline L; Yaqub, Mohammad; Papageorghiou, Aris T; Rahmatullah, Bahbibi; Foi, Alessandro; Maggioni, Matteo; Pepe, Antonietta; Tohka, Jussi; Stebbing, Richard V; McManigle, John E; Ciurte, Anca; Bresson, Xavier; Cuadra, Meritxell Bach; Sun, Changming; Ponomarev, Gennady V; Gelfand, Mikhail S; Kazanov, Marat D; Wang, Ching-Wei; Chen, Hsiang-Chou; Peng, Chun-Wei; Hung, Chu-Mei; Noble, J Alison

2014-04-01

This paper presents the evaluation results of the methods submitted to Challenge US: Biometric Measurements from Fetal Ultrasound Images, a segmentation challenge held at the IEEE International Symposium on Biomedical Imaging 2012. The challenge was set to compare and evaluate current fetal ultrasound image segmentation methods. It consisted of automatically segmenting fetal anatomical structures to measure standard obstetric biometric parameters, from 2D fetal ultrasound images taken on fetuses at different gestational ages (21 weeks, 28 weeks, and 33 weeks) and with varying image quality to reflect data encountered in real clinical environments. Four independent sub-challenges were proposed, according to the objects of interest measured in clinical practice: abdomen, head, femur, and whole fetus. Five teams participated in the head sub-challenge and two teams in the femur sub-challenge, including one team who tackled both. Nobody attempted the abdomen and whole fetus sub-challenges. The challenge goals were two-fold and the participants were asked to submit the segmentation results as well as the measurements derived from the segmented objects. Extensive quantitative (region-based, distance-based, and Bland-Altman measurements) and qualitative evaluation was performed to compare the results from a representative selection of current methods submitted to the challenge. Several experts (three for the head sub-challenge and two for the femur sub-challenge), with different degrees of expertise, manually delineated the objects of interest to define the ground truth used within the evaluation framework. For the head sub-challenge, several groups produced results that could be potentially used in clinical settings, with comparable performance to manual delineations. The femur sub-challenge had inferior performance to the head sub-challenge due to the fact that it is a harder segmentation problem and that the techniques presented relied more on the femur's appearance.

Effect of divalent (Sr, Ba) doping on the structural and magnetic properties of BiFeO{sub 3}

Energy Technology Data Exchange (ETDEWEB)

Rangi, Manisha, E-mail: mrangi100@gmail.com; Sanghi, Sujata; Agarwal, Ashish; Jangra, Sandhaya; Singh, Ompal [Department of Applied Physics, Guru Jambheshwar University of Science and Technology, Hisar, Haryana- 125001 (India)

2015-06-24

The effect of divalent substitution on the crystal structure and magnetic properties of BiFeO{sub 3} has been investigated using X-ray diffraction and magnetic measurements technique. Single phase Bi{sub 0.8}A{sub 0.2}FeO{sub 3} (A= Sr, Ba) multiferroics have been synthesized by solid state reaction method. Rietveld analysis of the XRD patterns revealed that the prepared ceramics exhibit rhombohedral structure with space group R3c. M–H hysteresis loops were recorded at 5K revealed that Sr and Ba substitution transformed antiferromagnetic BiFeO3 into weak ferromagnetic. The enhanced magnetization with Sr and Ba addition is confirmed by the MT curve recorded at 1T. It is closely related to intrinsic structural distortion and modification of the antiparallel spin structure.

Estudio de la región rica en Bi2O3 en el sistema binario ZnO-Bi2O3

Directory of Open Access Journals (Sweden)

Caballero, A. C.

2004-08-01

Full Text Available Ceramic materials based in the ZnO- Bi2O3 system have their principal application as varistors. The binary system ZnO-Bi2O3 is specially relevant to the formation of the microstructure responsable of the varistor behaviour. The study of the different equilibrium phases at high temperatures at the Bi2O3-rich region of the ZnO-Bi2O3 will allow a correct understanding of the microstructural development. Equilibrium phases have been analyzed by XRD, SEM and DTA. Different temperature treatments of samples formulated in the Bi2O3 rich region of the ZnO-Bi2O3 binary system have allowed to determine the phase 19Bi2O3•ZnO as the equilibrium one instead of the 24Bi2O3•ZnO phase.Los materiales cerámicos basados en el sistema binario ZnO-Bi2O3 tienen su principal aplicación en el campo de los varistores. El sistema binario ZnO-Bi2O3 resulta especialmente relevante para la formación de la microestructura funcional de varistores. La determinación de las diferentes fases en equilibrio a alta temperatura en la región rica en Bi2O3 en el sistema binario ZnO-Bi2O3 permitirá interpretar correctamente el desarrollo microestructural. El estudio de las fases en equilibrio se ha llevado a cabo mediante difracción de rayos X, microscopía electrónica de barrido (MEB y análisis térmico diferencial (ATD. Tratamientos a diferentes temperaturas, en la zona rica en Bi2O3 del sistema, han permitido determinar la presencia del compuesto 19Bi2O3•ZnO como fase estable en equilibrio, en lugar del compuesto 24Bi2O3•ZnO.

Orthonormal bases for anisotropic α-modulation spaces

DEFF Research Database (Denmark)

Rasmussen, Kenneth Niemann

2012-01-01

In this article we construct orthonormal bases for bi-variate anisotropic α-modulation spaces. The construction is based on generating a nice anisotropic α-covering and using carefully selected tensor products of univariate brushlet functions with regards to this covering. As an application, we...... show that n-term nonlinear approximation with the orthonormal bases in certain anisotropic α-modulation spaces can be completely characterized....

Orthonormal bases for anisotropic α-modulation spaces

DEFF Research Database (Denmark)

Rasmussen, Kenneth Niemann

In this article we construct orthonormal bases for bi-variate anisotropic α-modulation spaces. The construction is based on generating a nice anisotropic α-covering and using carefully selected tensor products of univariate brushlet functions with regards to this covering. As an application, we...... show that n-term nonlinear approximation with the orthonormal bases in certain anisotropic α-modulation spaces can be completely characterized....

TiO2/Bi2(BDC)3/BiOCl nanoparticles decorated ultrathin nanosheets with excellent photocatalytic reaction activity and selectivity

International Nuclear Information System (INIS)

Zhou, Shu-Mei; Ma, De-Kun; Cai, Ping; Chen, Wei; Huang, Shao-Ming

2014-01-01

Graphical abstract: TiO 2 /Bi 2 (BDC) 3 /BiOCl nanoparticles decorated ultrathin nanosheets showed excellent photocatalytic reaction activity and selectivity. - Highlights: • TiO 2 /Bi 2 (BDC) 3 /BiOCl nanoparticles decorated ultrathin nanosheets were synthesized through a facile hydrothermal process. • The products showed excellent photocatalytic activities for the degradation of various dyes. • The photocatalytic activities of the composite materials could be easily adjusted through tuning the content of TiO 2 . • TiO 2 /Bi 2 (BDC) 3 /BiOCl displayed obvious photocatalytic selectivity in mixed dyes systems of rhodamine B and eosin Y. - Abstract: Photocatalysts with excellent photocatalytic reaction activity and ideal selectivity are highly desirable for pollutants clearance and purification of targeted organics from a mixture. Continued efforts toward the goal, we here present a facile hydrothermal route to synthesize TiO 2 /Bi-benzenedicarboxylate/BiOCl nanoparticles decorated ultrathin nanosheets with a thickness less than 5 nm on a large scale. The as-synthesized products showed excellent photocatalytic activities for the degradation of various dyes such as rhodamine B, eosin Y and methylene blue in aqueous solution under visible light irradiation. The photocatalytic activities of TiO 2 /Bi-benzenedicarboxylate/BiOCl nanocomposites for the degradation of rhodamine B and eosin Y could be adjusted through tuning the content of TiO 2 . With increasing the amount of TiO 2 , the composites showed declining photocatalytic activities in decomposing of rhodamine B while on the contrary they displayed enhanced photocatalytic activities in decomposing of eosin Y. Interestingly, TiO 2 /Bi-benzenedicarboxylate/BiOCl composite nanosheets showed obvious photocatalytic selectivity in a mixed dyes system. The photocatalytic reaction and selectivity mechanisms of the nanocomposites for the degradation of the dyes were discussed on the basis of experimental results. The

Thermoelectric power of Bi and Bi{sub 1{minus}x}Sb{sub x} alloy thin films and superlattices grown by MBE

Energy Technology Data Exchange (ETDEWEB)

Cho, S; DiVenere, A; Wong, G K; Ketterson, J B; Meyer, J R; Hoffman, C A

1997-07-01

The authors have measured the thermoelectric power (TEP) of MBE-grown epitaxial Bi and Bi{sub 1{minus}x} alloy thin films and superlattices as a function of temperature in the range 20--300 K. They have observed that the TEP of a Bi thin film of 1 {micro}m thickness is in good agreement with the bulk single crystal value and that the TEPs for superlattices with 400 {angstrom} and 800 {angstrom} Bi well thicknesses are enhanced over the bulk values. For x = 0.072 and 0.088 in Bi{sub 1{minus}x}Sb{sub x} thin films showing semiconducting behavior, TEP enhancement was observed by a factor of two. However as Bi or Bi{sub 1{minus}x}Sb{sub x} well thickness decreases in superlattice geometry, the TEP decreases, which may be due to unintentional p-type doping.

Electrical analysis of inter-growth structured Bi4Ti3O12-Na0.5Bi4.5Ti4O15 ceramics

Science.gov (United States)

Jiang, Xiangping; Jiang, Yalin; Jiang, Xingan; Chen, Chao; Tu, Na; Chen, Yunjing

2017-06-01

Inter-growth bismuth layer-structured ferroelectrics (BLSFs), Bi4Ti3O12-Na0.5Bi4.5Ti4O15 (BIT-NBT), were successfully synthesized using the traditional solid-state reaction method. X-ray diffraction (XRD) Rietveld refinements were conducted using GSAS software. Good agreement and low residual are obtained. The XRD diffraction peaks can be well indexed into I2cm space group. The inter-growth structure was further observed in the high-resolution TEM image. Dielectric and impedance properties were measured and systematically analyzed. At the temperature range 763-923 K (below {T}{{c}}), doubly ionized oxygen vacancies (OVs) are localized and the short-range hopping leads to the relaxation processes with an activation energy of 0.79-1.01 eV. Above {T}{{c}}, the doubly charged OVs are delocalized and become free ones, which contribute to the long-range dc conduction. The reduction in relaxation species gives rise to a higher relaxation activation energy ˜1.6  eV. Project supported by the National Natural Science Foundation of China (Grant Nos. 51562014, 51262009, and 51602135).

Agrobacterium-mediated transformation of Citrus sinensis and Citrus limonia epicotyl segments

OpenAIRE

Almeida,Weliton Antonio Bastos de; Mourão Filho,Francisco de Assis Alves; Mendes,Beatriz Madalena Januzzi; Pavan,Alexandra; Rodriguez,Adriana Pinheiro Martinelli

2003-01-01

Genetic transformation allows the release of improved cultivars with desirable characteristics in a shorter period of time and therefore may be useful in citrus breeding programs. The objective of this research was to establish a protocol for genetic transformation of Valencia and Natal sweet oranges (Citrus sinensis L. Osbeck) and Rangpur lime (Citrus limonia L. Osbeck). Epicotyl segments of germinated in vitro plantlets (three weeks in darkness and two weeks in a 16-h photoperiod) were used...

BiP Negatively Affects Ricin Transport

Directory of Open Access Journals (Sweden)

Kirsten Sandvig

2013-05-01

Full Text Available The AB plant toxin ricin binds both glycoproteins and glycolipids at the cell surface via its B subunit. After binding, ricin is endocytosed and then transported retrogradely through the Golgi to the endoplasmic reticulum (ER. In the ER, the A subunit is retrotranslocated to the cytosol in a chaperone-dependent process, which is not fully explored. Recently two separate siRNA screens have demonstrated that ER chaperones have implications for ricin toxicity. ER associated degradation (ERAD involves translocation of misfolded proteins from ER to cytosol and it is conceivable that protein toxins exploit this pathway. The ER chaperone BiP is an important ER regulator and has been implicated in toxicity mediated by cholera and Shiga toxin. In this study, we have investigated the role of BiP in ricin translocation to the cytosol. We first show that overexpression of BiP inhibited ricin translocation and protected cells against the toxin. Furthermore, shRNA-mediated depletion of BiP enhanced toxin translocation resulting in increased cytotoxicity. BiP-dependent inhibition of ricin toxicity was independent of ER stress. Our findings suggest that in contrast to what was shown with the Shiga toxin, the presence of BiP does not facilitate, but rather inhibits the entry of ricin into the cytosol.

Segmented block copolymers with monodisperse aramide end-segments

NARCIS (Netherlands)

Araichimani, A.; Gaymans, R.J.

2008-01-01

Segmented block copolymers were synthesized using monodisperse diaramide (TT) as hard segments and PTMO with a molecular weight of 2 900 g · mol-1 as soft segments. The aramide: PTMO segment ratio was increased from 1:1 to 2:1 thereby changing the structure from a high molecular weight multi-block

Marginal space learning for medical image analysis efficient detection and segmentation of anatomical structures

CERN Document Server

Zheng, Yefeng

2014-01-01

Presents an award winning image analysis technology (Thomas Edison Patent Award, MICCAI Young Investigator Award) that achieves object detection and segmentation with state-of-the-art accuracy and efficiency Flexible, machine learning-based framework, applicable across multiple anatomical structures and imaging modalities Thirty five clinical applications on detecting and segmenting anatomical structures such as heart chambers and valves, blood vessels, liver, kidney, prostate, lymph nodes, and sub-cortical brain structures, in CT, MRI, X-Ray and Ultrasound.

Central nervous system involvement in a case of segmental nevus depigmentosus

Directory of Open Access Journals (Sweden)

Ishita Majumdar

2016-01-01

Full Text Available Central nervous system involvement in segmental nevus depigmentosus (SND is rare. A 7-month-old boy having convulsion and segmental hypopigmented patch in the right inguinal region. Magnetic resonance imaging of brain showed bilateral periventricular white matter hypoplasia with prominent subarachnoid spaces and mild dilation of ventricles with mild left cerebral hemispheric atrophy. Association of SND with seizure and white matter lesion has been rarely reported.

White blood cell counting analysis of blood smear images using various segmentation strategies

Science.gov (United States)

Safuan, Syadia Nabilah Mohd; Tomari, Razali; Zakaria, Wan Nurshazwani Wan; Othman, Nurmiza

2017-09-01

In white blood cell (WBC) diagnosis, the most crucial measurement parameter is the WBC counting. Such information is widely used to evaluate the effectiveness of cancer therapy and to diagnose several hidden infection within human body. The current practice of manual WBC counting is laborious and a very subjective assessment which leads to the invention of computer aided system (CAS) with rigorous image processing solution. In the CAS counting work, segmentation is the crucial step to ensure the accuracy of the counted cell. The optimal segmentation strategy that can work under various blood smeared image acquisition conditions is remain a great challenge. In this paper, a comparison between different segmentation methods based on color space analysis to get the best counting outcome is elaborated. Initially, color space correction is applied to the original blood smeared image to standardize the image color intensity level. Next, white blood cell segmentation is performed by using combination of several color analysis subtraction which are RGB, CMYK and HSV, and Otsu thresholding. Noises and unwanted regions that present after the segmentation process is eliminated by applying a combination of morphological and Connected Component Labelling (CCL) filter. Eventually, Circle Hough Transform (CHT) method is applied to the segmented image to estimate the number of WBC including the one under the clump region. From the experiment, it is found that G-S yields the best performance.

Segmentation of consumer's markets and evaluation of market's segments

OpenAIRE

ŠVECOVÁ, Iveta

2013-01-01

The goal of this bachelor thesis was to explain a possibly segmentation of consumer´s markets for a chosen company, and to present a suitable goods offer, so it would be suitable to the needs of selected segments. The work is divided into theoretical and practical part. First part describes marketing, segmentation, segmentation of consumer's markets, consumer's market, market's segments a other terms. Second part describes an evaluation of questionnaire survey, discovering of market's segment...

[Evaluation of Image Quality of Readout Segmented EPI with Readout Partial Fourier Technique].

Science.gov (United States)

Yoshimura, Yuuki; Suzuki, Daisuke; Miyahara, Kanae

Readout segmented EPI (readout segmentation of long variable echo-trains: RESOLVE) segmented k-space in the readout direction. By using the partial Fourier method in the readout direction, the imaging time was shortened. However, the influence on image quality due to insufficient data sampling is concerned. The setting of the partial Fourier method in the readout direction in each segment was changed. Then, we examined signal-to-noise ratio (SNR), contrast-to-noise ratio (CNR), and distortion ratio for changes in image quality due to differences in data sampling. As the number of sampling segments decreased, SNR and CNR showed a low value. In addition, the distortion ratio did not change. The image quality of minimum sampling segments is greatly different from full data sampling, and caution is required when using it.

Structural study of intermediate phase in layered perovskite SrBi sub 2 Ta sub 2 O sub 9 single crystal

CERN Document Server

Onodera, A; Yamashita, H

2003-01-01

The crystal structure of an intermediate phase of Bi-layered ferroelectric SrBi sub 2 Ta sub 2 O sub 9 single crystals was studied by means of X-ray diffraction. An analysis of the extinction rules and X-ray intensities demonstrated that the crystal structure is orthorhombic with space group A2 sub 1 am in the ferroelectric phase and Amam in the intermediate phase; this conclusion is in good agreement with the findings of previous powder neutron diffraction studies.

Synthesis, crystal structure, and nonlinear optical properties of Bi2Cu5B4O14

International Nuclear Information System (INIS)

Pan Shilie; Smit, Jared P.; Marvel, Michael R.; Stampler, Evan S.; Haag, Jacob M.; Baek, Jaewook; Halasyamani, P. Shiv; Poeppelmeier, Kenneth R.

2008-01-01

Bi 2 Cu 5 B 4 O 14 crystallizes in the noncentrosymmetric triclinic space group P1 (No. 1) with cell parameters a=10.1381(11) A, b=9.3917(11) A, c=3.4566(4) A, α=105.570(2) o , β=92.275(2) o , γ=107.783(2) o , Z=1 and R 1 =0.0401 and wR 2 =0.0980. It is a layered structure that is built up from sheets of rectangular CuO 4 and trigonal BO 3 groups. The sheets are connected by infinite chains of edge shared BiO 6 polyhedra that intersect the bc plane at an angle slightly greater than 90 o . The second-harmonic generation efficiency of Bi 2 Cu 5 B 4 O 14 , using 1064 nm radiation, is about one half times that of KH 2 PO 4 . - Graphical abstract: The figure shows a layered structure that is built up from sheets of distorted rectangular CuO 4 and trigonal BO 3 groups. The sheets are connected by infinite chains of edge shared BiO 6 polyhedra that intersect the bc plane. These distortions lead to the second-harmonic generation efficiency of Bi 2 Cu 5 B 4 O 14 about one half times that of KH 2 PO 4 Display Omitted

Thermoelectric properties of Bi2Te3 base solid solutions in the Bi2Te3-InS system

International Nuclear Information System (INIS)

Safarov, M.G.; Rustamov, P.G.; Alidzhanov, M.A.

1979-01-01

The rich Bi 2 Te 3 part ot the Bi 2 Te 3 -InS constitutional diagram has been studied with a view to produce new Bi 2 Te 3 -based solid solutions and to establish the maximum solubility of InS in Bi 2 Te 3 . The methods of differential-thermal, X-ray phase and microstructural analysis have been used. The alloys microhardness, density and thermal electric properties have been measured. A large region of Bi 2 Te 3 -based restricted solid solutions has been detected; it reaches 14.0 mol.% InS at room temperature. Studied have been the thermoelectromotive forces, electric and thermal conductivity of the alloys, containing up to 5 mol.% InS in the 300-700 K temperature range

Using external and internal locking plates in a two-stage protocol for treatment of segmental tibial fractures.

Science.gov (United States)

Ma, Ching-Hou; Tu, Yuan-Kun; Yeh, Jih-Hsi; Yang, Shih-Chieh; Wu, Chin-Hsien

2011-09-01

The tibial segmental fractures usually follow high-energy trauma and are often associated with many complications. We designed a two-stage protocol for these complex injuries. The aim of this study was to assess the outcome of tibial segmental fractures treated according to this protocol. A prospective series of 25 consecutive segmental tibial fractures were treated using a two-stage procedure. In the first stage, a low-profile locking plate was applied as an external fixator to temporarily immobilize the fractures after anatomic reduction had been achieved followed by soft-tissue reconstruction. The second stage involved definitive internal fixation with a locking plate using a minimally invasive percutaneous plate osteosynthesis technique. The median follow-up was 32 months (range, 20-44 months). All fractures achieved union. The median time for the proximal fracture union was 23 weeks (range, 12-30 weeks) and that for distal fracture union was 27 weeks (range, 12-46 weeks; p = 0.08). Functional results were excellent in 21 patients and good in 4 patients. There were three cases of delayed union of distal fracture. Valgus malunion >5 degrees occurred in two patients, and length discrepancy >1 cm was observed in two patients. Pin tract infection occurred in three patients. Use of the two-stage procedure for treatment of segmental tibial fractures is recommended. Surgeons can achieve good reduction with stable temporary fixation, soft-tissue reconstruction, ease of subsequent definitive fixation, and high union rates. Our patients obtained excellent knee and ankle joint motion, good functional outcomes, and a comfortable clinical course.

Optical spectroscopy and Fermi surface studies of BiTeCl and BiTeBr

Science.gov (United States)

Martin, Catalin; Suslov, A. V.; Buvaev, S.; Hebard, A. F.; Bugnon, Philippe; Berger, Helmuth; Magrez, Arnaud; Tanner, D. B.

2014-03-01

The observation of a large bulk Rashba effect in the non-centrosymmetric semiconductors BiTeX(X=Cl, Br, I) has stimulated the interest in these sys- tems, as promising candidates for studying spin related phenomena and for the realization of spin devices. Here we present a comparative study of the electronic properties of BiTeCl and BiTeBr, determined from temperature dependent infrared spectroscopy and Shubnikov-de Haas oscillations. In par- ticular, we compare the angle dependence of quantum oscillations between the two compounds and discuss possible differences between the topology of their Fermi surfaces. Supported by NSF Cooperative Agreement DMR-1157490 to the National High Magnetic Field Laboratory.

GenProBiS: web server for mapping of sequence variants to protein binding sites.

Science.gov (United States)

Konc, Janez; Skrlj, Blaz; Erzen, Nika; Kunej, Tanja; Janezic, Dusanka

2017-07-03

Discovery of potentially deleterious sequence variants is important and has wide implications for research and generation of new hypotheses in human and veterinary medicine, and drug discovery. The GenProBiS web server maps sequence variants to protein structures from the Protein Data Bank (PDB), and further to protein-protein, protein-nucleic acid, protein-compound, and protein-metal ion binding sites. The concept of a protein-compound binding site is understood in the broadest sense, which includes glycosylation and other post-translational modification sites. Binding sites were defined by local structural comparisons of whole protein structures using the Protein Binding Sites (ProBiS) algorithm and transposition of ligands from the similar binding sites found to the query protein using the ProBiS-ligands approach with new improvements introduced in GenProBiS. Binding site surfaces were generated as three-dimensional grids encompassing the space occupied by predicted ligands. The server allows intuitive visual exploration of comprehensively mapped variants, such as human somatic mis-sense mutations related to cancer and non-synonymous single nucleotide polymorphisms from 21 species, within the predicted binding sites regions for about 80 000 PDB protein structures using fast WebGL graphics. The GenProBiS web server is open and free to all users at http://genprobis.insilab.org. © The Author(s) 2017. Published by Oxford University Press on behalf of Nucleic Acids Research.

Magnetoelectric properties of Pb free Bi2FeTiO6: A theoretical investigation

Science.gov (United States)

Patra, Lokanath; Ravindran, P.

2018-05-01

The structural, electronic, magnetic and ferroelectric properties of Pb free double perovskite multiferroic Bi2FeTiO6 are investigated using density functional theory within the general gradient approximation (GGA) method. Our structural optimization using total energy calculations for different potential structures show a minimum energy for a non-centrosymmetric rhombohedral structure with R3c space group. Bi2FeTiO6 is found to be an antiferromagnetic insulator with C-type magnetic ordering with bandgap value of 0.3 eV. The calculated magnetic moment of 3.52 μB at Fe site shows the high spin arrangement of 3d electrons which is also confirmed by our orbital projected density of states analysis. We have analyzed the characteristics of bonding present between the constituents of Bi2FeTiO6 with the help of calculated partial density of states and Born effective charges. The ground state of the nearest centrosymmetric structure is found to be a G-type antiferromagnet with half metallicity showing that by the application of external electric field we can not only get a polarized state but also change the magnetic ordering and electronic structure in the present compound indicating strong magnetoelectric coupling. The cation sites the coexistence of Bi 6s lone pair (bring disproportionate charge distribution) and Ti4+ d0 ions which brings covalency produces off-center displacement and favors a non-centrosymmetric ground state and thus ferroelectricity. Our Berry phase calculation gives a polarization of 48 µCcm-2 for Bi2FeTiO6.

Low-temperature phase MnBi compound: A potential candidate for rare-earth free permanent magnets

International Nuclear Information System (INIS)

Ly, V.; Wu, X.; Smillie, L.; Shoji, T.; Kato, A.; Manabe, A.; Suzuki, K.

2014-01-01

Highlights: • The spin reorientation temperature of MnBi is suppressed by nanoscale grain refinement. • Hardness parameter of MnBi reaches as large as 2.8 at 580 K. • MnBi has a great potential as a hard phase in rare-earth free nanocomposite magnets. • Improving the surface passivity is a remaining task for MnBi-based permanent magnets. - Abstract: The low-temperature phase (LTP) MnBi is one of the few rare-earth free compounds that exhibit a large magnetocrystalline anisotropy energy in the order of 10 6 J/m 3 . A large coercive field (μ 0 H cj ) above 1 T can be obtained readily by reducing the crystallite size (D) through mechanical grinding (MG). The room-temperature H cj values follow a phenomenological expression μ 0 H cj = μ 0 H a (δ/D) n where the anisotropy field (μ 0 H a ) is ∼4 T, the Bloch wall width (δ) is 7 nm and the exponent (n) is about 0.7 in our study. The grain refinement upon MG is accompanied by suppression of the spin reorientation transition temperature (T SR ) from 110 K to below 50 K. The coercive field starts to exhibit positive temperature dependence approximately 50 K above T SR and the room-temperature magnetic hardening induced by MG could partially be brought about by the lowered onset of this positive temperature dependence. The suppression of T SR by MG is likely to be induced by the surface anisotropy with which the 2nd order crystal field term is enhanced. One of the shortcomings of LTP-MnBi is its poor phase stability under the ambient atmosphere. The spontaneous magnetization decreases considerably after room-temperature aging for 1 week. This is due to oxidation of Mn which leads to decomposition of the MnBi phase. Hence, the surface passivity needs to be established before this material is considered for a permanent magnet in practical uses. Another shortcoming is the limited spontaneous magnetization. The theoretical upper limit of the maximum energy product in LTP-MnBi remains only a quarter of that in Nd 2

Low-temperature phase MnBi compound: A potential candidate for rare-earth free permanent magnets

Energy Technology Data Exchange (ETDEWEB)

Ly, V.; Wu, X.; Smillie, L. [Department of Materials Engineering, Monash University, Clayton, VIC 3800 (Australia); Shoji, T.; Kato, A.; Manabe, A. [Toyota Motor Corporation, Mishuku, Susono, Shizuoka 410-1193 (Japan); Suzuki, K., E-mail: kiyonori.suzuki@monash.edu [Department of Materials Engineering, Monash University, Clayton, VIC 3800 (Australia)

2014-12-05

Highlights: • The spin reorientation temperature of MnBi is suppressed by nanoscale grain refinement. • Hardness parameter of MnBi reaches as large as 2.8 at 580 K. • MnBi has a great potential as a hard phase in rare-earth free nanocomposite magnets. • Improving the surface passivity is a remaining task for MnBi-based permanent magnets. - Abstract: The low-temperature phase (LTP) MnBi is one of the few rare-earth free compounds that exhibit a large magnetocrystalline anisotropy energy in the order of 10{sup 6} J/m{sup 3}. A large coercive field (μ{sub 0}H{sub cj}) above 1 T can be obtained readily by reducing the crystallite size (D) through mechanical grinding (MG). The room-temperature H{sub cj} values follow a phenomenological expression μ{sub 0}H{sub cj} = μ{sub 0}H{sub a}(δ/D){sup n} where the anisotropy field (μ{sub 0}H{sub a}) is ∼4 T, the Bloch wall width (δ) is 7 nm and the exponent (n) is about 0.7 in our study. The grain refinement upon MG is accompanied by suppression of the spin reorientation transition temperature (T{sub SR}) from 110 K to below 50 K. The coercive field starts to exhibit positive temperature dependence approximately 50 K above T{sub SR} and the room-temperature magnetic hardening induced by MG could partially be brought about by the lowered onset of this positive temperature dependence. The suppression of T{sub SR} by MG is likely to be induced by the surface anisotropy with which the 2nd order crystal field term is enhanced. One of the shortcomings of LTP-MnBi is its poor phase stability under the ambient atmosphere. The spontaneous magnetization decreases considerably after room-temperature aging for 1 week. This is due to oxidation of Mn which leads to decomposition of the MnBi phase. Hence, the surface passivity needs to be established before this material is considered for a permanent magnet in practical uses. Another shortcoming is the limited spontaneous magnetization. The theoretical upper limit of the maximum

Effect of polarizable lone pair cations on the second-harmonic generation (SHG) properties of noncentrosymmetric (NCS) Bi(2-x)Y(x)TeO₅ (x = 0-0.2).

Science.gov (United States)

Jo, Hongil; Kim, Yeong Hun; Lee, Dong Woo; Ok, Kang Min

2014-08-14

Y(3+)-doped noncentrosymmetric (NCS) bismuth tellurite materials, Bi(2-x)Y(x)TeO5 (x = 0, 0.1, and 0.2), have been synthesized through standard solid-state reactions and structurally characterized by powder neutron diffraction. The reported NCS materials crystallize in the orthorhombic space group Abm2 (no. 39), and exhibit pseudo-three-dimensional frameworks that are composed of BiO3, BiO5, and TeO3 polyhedra. Detailed diffraction studies show that the cell volume of Bi(2-x)Y(x)TeO5 decreases with an increasing amount of Y(3+)on the Bi(3+) sites. However, no ordering between Bi(3+) and Y(3+) was observed in the Bi(2-x)Y(x)TeO5. Powder second-harmonic generation (SHG) measurements, using 1064 nm radiation, reveal that Bi2TeO5, Bi(1.9)Y(0.1)TeO5, and Bi(1.8)Y(0.2)TeO5 exhibit SHG efficiencies of approximately 300, 200, and 60 times that of α-SiO2, respectively. The reduction in SHG for Y(3+)-doped materials is consistent with the lack of net moment originating from polyhedra with a polarizable Bi(3+) cation.

Bi-cooperative games in bipolar fuzzy settings

Science.gov (United States)

Hazarika, Pankaj; Borkotokey, Surajit; Mesiar, Radko

2018-01-01

In this paper, we introduce the notion of a bi-cooperative game with Bipolar Fuzzy Bi-coalitions and discuss the related properties. In many decision-making situations, players show bipolar motives while cooperating among themselves. This is modelled in both crisp and fuzzy environments. Bi-cooperative games with fuzzy bi-coalitions have already been proposed under the product order of bi-coalitions where one had memberships in [0, 1]. In the present paper, we adopt the alternative ordering: ordering by monotonicity and account for players' memberships in ?, a break from the previous formulation. This simplifies the model to a great extent. The corresponding Shapley axioms are proposed. An explicit form of the Shapley value to a particular class of such games is also obtained. Our study is supplemented with an illustrative example.

Large aperture telescope technology: a design for an active lightweight multi-segmented fold-out space mirror

Science.gov (United States)

Thompson, S. J.; Doel, A. P.; Whalley, M.; Edeson, R.; Edeson, R.; Tosh, I.; Poyntz-Wright, O.; Atad-Ettedgui, E.; Montgomery, D.; Nawasra, J.

2017-11-01

Large aperture telescope technology (LATT) is a design study for a differential lidar (DIAL) system; the main investigation being into suitable methods, technologies and materials for a 4-metre diameter active mirror that can be stowed to fit into a typical launch vehicle (e.g. ROKOT launcher with 2.1-metre diameter cargo) and can self-deploy - in terms of both leaving the space vehicle and that the mirrors unfold and self-align to the correct optical form within the tolerances specified. The primary mirror requirements are: main wavelength of 935.5 nm, RMS corrected wavefront error of λ/6, optical surface roughness better than 5 nm, areal density of less than 16 kg/m2 and 1-2 mirror shape corrections per orbit. The primary mirror consists of 7 segments - a central hexagonal mirror and 6 square mirror petals which unfold to form the 4-meter diameter aperture. The focus of the UK LATT consortium for this European Space Agency (ESA) funded project is on using lightweighted aluminium or carbon-fibre-composite materials for the mirror substrate in preference to more traditional materials such as glass and ceramics; these materials have a high strength and stiffness to weight ratio, significantly reducing risk of damage due to launch forces and subsequent deployment in orbit. We present an overview of the design, which includes suitable actuators for wavefront correction, petal deployment mechanisms and lightweight mirror technologies. Preliminary testing results from manufactured lightweight mirror samples will also be summarised.

Joint statistics and conditional mean strain rates of streamline segments

International Nuclear Information System (INIS)

Schaefer, P; Gampert, M; Peters, N

2013-01-01

Based on four different direct numerical simulations of turbulent flows with Taylor-based Reynolds numbers ranging from Re λ = 50 to 300 among which are two homogeneous isotropic decaying, one forced and one homogeneous shear flow, streamlines are identified and the obtained space curves are parameterized with the pseudo-time as well as the arclength. Based on local extrema of the absolute value of the velocity along the streamlines, the latter are partitioned into segments following Wang (2010 J. Fluid Mech. 648 183–203). Streamline segments are then statistically analyzed based on both parameterizations using the joint probability density function of the pseudo-time lag τ (arclength l, respectively) between and the velocity difference Δu at the extrema: P(τ,Δu), (P(l,Δu)). We distinguish positive and negative streamline segments depending on the sign of the velocity difference Δu. Differences as well as similarities in the statistical description for both parameterizations are discussed. In particular, it turns out that the normalized probability distribution functions (pdfs) (of both parameterizations) of the length of positive, negative and all segments assume a universal shape for all Reynolds numbers and flow types and are well described by a model derived in Schaefer P et al (2012 Phys. Fluids 24 045104). Particular attention is given to the conditional mean velocity difference at the ending points of the segments, which can be understood as a first-order structure function in the context of streamline segment analysis. It determines to a large extent the stretching (compression) of positive (negative) streamline segments and corresponds to the convective velocity in phase space in the transport model equation for the pdf. While based on the random sweeping hypothesis a scaling ∝ (u rms ετ) 1/3 is found for the parameterization based on the pseudo-time, the parameterization with the arclength l yields a much larger than expected l 1/3 scaling. A

Growth of nucleation sites on Pb-doped Bi2Sr2Ca1Cu2O8+δ

International Nuclear Information System (INIS)

Finnemore, D.K.; Xu, M.; Kouzoudis, D.; Bloomer, T.; Kramer, M.J.; McKernan, S.; Balachandran, U.; Haldar, P.

1996-01-01

In the growth of Bi 2 Sr 2 Ca 2 Cu 3 O 10+δ from mixed powders of Pb-doped Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ and other oxides, it has been discovered that a dense array of hillocks or mesas grow at the interface between a Ag overlay and Pb-doped Bi 2 Sr 2 Ca 1 Cu 2 O 8+δ grains during the ramp up to the reaction temperature. As viewed in an environmental scanning electron microscope, the Ag coated grains develop a texture that looks like open-quote open-quote chicken pox close-quote close-quote growing on the grains at about 700 degree C. These hillocks are about 100 nm across and are spaced at about 500 to 1000 nm. If there is no Ag, this texture does not develop. Preliminary measurements indicate that the hillocks are a recrystallization of (Bi,Pb) 2 Sr 2 Ca 1 Cu 2 O 8+δ , and are definitely not a Pb rich phase. copyright 1996 American Institute of Physics

Propellant Gelation for Green In-Space Propulsion, Phase I

Data.gov (United States)

National Aeronautics and Space Administration — Concerns in recent years about the toxicity and safe handling of the storable class of propellants have led to efforts in greener monopropellants and bi-propellants....

Autofluorescence from the outer retina and subretinal space: hypothesis and review.

Science.gov (United States)

Spaide, Richard

2008-01-01

To review the pathophysiologic principles underlying increased autofluorescence from the outer retina and subretinal space using selected diseases as examples. The ocular imaging information and histopathologic features, when known, were integrated for diseases causing increased autofluorescence from the outer retina and subretinal space. Inferences were taken from this information and used to create a classification scheme. These diseases are principally those that cause separation of the outer retina from the retinal pigment epithelium, thereby preventing proper phagocytosis of photoreceptor outer segments. The separation can arise from increased exudation into the subretinal space or inadequate removal of fluid from the subretinal space. Lack of normal outer segment processing initially leads to increased accumulation of outer segments on the outer retina and subretinal space. Over time, this material is visible as an increasingly thick coating on the outer retina, is yellow, and is autofluorescent. Over time, atrophy develops with thinning of the deposited material and decreasing autofluorescence. The accumulated material is ultimately capable of inducing damage to the retinal pigment epithelium. Diseases causing accumulation of the material include central serous chorioretinopathy, vitelliform macular dystrophy, acute exudative polymorphous vitelliform maculopathy, choroidal tumors, and vitreomacular traction syndrome. The physical separation of the retinal outer segments from the retinal pigment epithelium hinders proper phagocytosis of the outer segments. Accumulation of the shed but not phagocytized outer segments plays a role in disease manifestations for a number of macular diseases.

Segmental maxillary distraction with a novel device for closure of a wide alveolar cleft.

Science.gov (United States)

Bousdras, Vasilios A; Liyanage, Chandra; Mars, Michael; Ayliffe, Peter R

2014-01-01

Treatment of a wide alveolar cleft with initial application of segmental distraction osteogenesis is reported, in order to minimise cleft size prior to secondary alveolar bone grafting. The lesser maxillary segment was mobilised with osteotomy at Le Fort I level and, a novel distractor, facilitated horizontal movement of the dental/alveolar segment along the curvature of the maxillary dental arch. Following a latency period of 4 days distraction was applied for 7 days at a rate of 0.5 mm twice daily. Radiographic, ultrasonographic and clinical assessment revealed new bone and soft tissue formation 8 weeks after completion of the distraction phase. Overall the maxillary segment did move minimising the width of the cleft, which allowed successful closure with a secondary alveolar bone graft.

Automatic segmentation of blood vessels from retinal fundus images ...

Indian Academy of Sciences (India)

The retinal blood vessels were segmented through color space conversion and color channel extraction, image pre-processing, Gabor filtering, image postprocessing, feature construction through application of principal component analysis, k-means clustering and first level classification using Naïve–Bayes classification ...

Establishing experimental model of human internal carotid artery siphon segment in canine common carotid artery

International Nuclear Information System (INIS)

Cui Xuee; Li Minghua; Wang Yongli; Cheng Yingsheng; Li Wenbin

2005-01-01

Objective: To study the feasibility of establishing experimental model of human internal carotid artery siphon segment in canine common carotid artery (CCA) by end-to-end anastomoses of one side common carotid artery segment with the other side common carotid artery. Methods: Surgical techniques were used to make siphon model in 8 canines. One side CCA was taken as the parent artery and anastomosing with the cut off contra-lateral CCA segment which has passed through within the S-shaped glass tube. Two weeks after the creation of models angiography showed the model siphons were patent. Results: Experimental models of human internal carotid artery siphon segment were successfully made in all 8 dogs. Conclusions: It is practically feasible to establish experimental canine common carotid artery models of siphon segment simulating human internal carotid artery. (authors)

EXTUBATE: A randomised controlled trial of nasal biphasic positive airway pressure vs. nasal continuous positive airway pressure following extubation in infants less than 30 weeks' gestation: study protocol for a randomised controlled trial

Directory of Open Access Journals (Sweden)

Victor Suresh

2011-12-01

Full Text Available Abstract Background Respiratory distress syndrome remains a significant problem among premature infants. Mechanical ventilation through an endotracheal tube remains the mainstay of respiratory support but may be associated with lung injury and the development of chronic lung disease of prematurity. Efforts are needed to reduce the duration of mechanical ventilation in favour of less invasive forms of respiratory support and to improve rates of successful extubation. Non-invasive respiratory support has been demonstrated to be less injurious to the premature lung. Standard practice is to use nasal continuous positive airway pressure (n-CPAP following extubation to support the baby's breathing. Many clinicians also use nasal biphasic positive airway pressure (n-BiPAP in efforts to improve rates of successful extubation. However, there is currently no evidence that this confers any advantage over conventional nasal continuous positive airway pressure. Methods We propose an unblinded multi-centre randomised trial comparing n-CPAP with n-BiPAP in babies born before 30 weeks' gestation and less than two weeks old. Babies with congenital abnormalities and severe intra-ventricular haemorrhage will be excluded. 540 babies admitted to neonatal centres in England will be randomised at the time of first extubation attempt. The primary aim of this study is to compare the rate of extubation failure within 48 hours following the first attempt at extubation. The secondary aims are to compare the effect of n-BiPAP and n-CPAP on the following outcomes: 1. Maintenance of successful extubation for 7 days post extubation 2. Oxygen requirement at 28 days of age and at 36 weeks' corrected gestational age 3. Total days on ventilator, n-CPAP/n-BiPAP 4. Number of ventilator days following first extubation attempt 5. pH and partial pressure of carbon dioxide in the first post extubation blood gas 6. Duration of hospital stay 7. Rate of abdominal distension requiring

Segmented focal plane detector for light and heavy ions

International Nuclear Information System (INIS)

Wolfs, F.L.H.; Bryan, D.C.; Kurz, K.L.; Herrick, D.M.; Perera, P.A.A.; White, C.A.

1992-01-01

A segmented focal plane detector for an Enge split-pole spectrograph has been developed for the study of breakup reactions at very low relative energies. It consists of a 61 cm long segmented position-sensitive parallel plate avalanche counter backed by a large Bragg curve detector. A segmented plastic scintillator is mounted behind the anode of the Bragg curve detector and is used for particle identification of low-ionizing particles. The dead space between the two sections of the focal plane detector is 2.5 mm. The intrinsic position resolution of the detector is 1 mm. The intrinsic energy resolution depends on the energy of the incident ion and can be as good as 0.55%. The nuclear charge and mass resolutions are 0.3 e and 0.3 u, respectively. (orig.)

Automated segmentation of pigmented skin lesions in multispectral imaging

International Nuclear Information System (INIS)

Carrara, Mauro; Tomatis, Stefano; Bono, Aldo; Bartoli, Cesare; Moglia, Daniele; Lualdi, Manuela; Colombo, Ambrogio; Santinami, Mario; Marchesini, Renato

2005-01-01

The aim of this study was to develop an algorithm for the automatic segmentation of multispectral images of pigmented skin lesions. The study involved 1700 patients with 1856 cutaneous pigmented lesions, which were analysed in vivo by a novel spectrophotometric system, before excision. The system is able to acquire a set of 15 different multispectral images at equally spaced wavelengths between 483 and 951 nm. An original segmentation algorithm was developed and applied to the whole set of lesions and was able to automatically contour them all. The obtained lesion boundaries were shown to two expert clinicians, who, independently, rejected 54 of them. The 97.1% contour accuracy indicates that the developed algorithm could be a helpful and effective instrument for the automatic segmentation of skin pigmented lesions. (note)

Randomized Controlled Trial of Hospital-Based Hygiene and Water Treatment Intervention (CHoBI7) to Reduce Cholera.

Science.gov (United States)

George, Christine Marie; Monira, Shirajum; Sack, David A; Rashid, Mahamud-ur; Saif-Ur-Rahman, K M; Mahmud, Toslim; Rahman, Zillur; Mustafiz, Munshi; Bhuyian, Sazzadul Islam; Winch, Peter J; Leontsini, Elli; Perin, Jamie; Begum, Farzana; Zohura, Fatema; Biswas, Shwapon; Parvin, Tahmina; Zhang, Xiaotong; Jung, Danielle; Sack, R Bradley; Alam, Munirul

2016-02-01

The risk for cholera infection is >100 times higher for household contacts of cholera patients during the week after the index patient seeks hospital care than it is for the general population. To initiate a standard of care for this high-risk population, we developed Cholera-Hospital-Based-Intervention-for-7-Days (CHoBI7), which promotes hand washing with soap and treatment of water. To test CHoBI7, we conducted a randomized controlled trial among 219 intervention household contacts of 82 cholera patients and 220 control contacts of 83 cholera patients in Dhaka, Bangladesh, during 2013-2014. Intervention contacts had significantly fewer symptomatic Vibrio cholerae infections than did control contacts and 47% fewer overall V. cholerae infections. Intervention households had no stored drinking water with V. cholerae and 14 times higher odds of hand washing with soap at key events during structured observation on surveillance days 5, 6, or 7. CHoBI7 presents a promising approach for controlling cholera among highly susceptible household contacts of cholera patients.

Layer structured bismuth selenides Bi2Se3 and Bi3Se4 for high energy and flexible all-solid-state micro-supercapacitors

Science.gov (United States)

Hao, Chunxue; Wang, Lidan; Wen, Fusheng; Xiang, Jianyong; Li, Lei; Hu, Wentao; Liu, Zhongyuan

2018-02-01

In this work, bismuth selenides (Bi2Se3 and Bi3Se4), both of which have a layered rhombohedral crystal structure, have been found to be useful as electrode materials for supercapacitor applications. In a liquid electrolyte system (6M KOH), Bi2Se3 nanoplates exhibit much better performance as an electrode material than Bi3Se4 nanoparticles do, delivering a higher specific capacitance (272.9 F g-1) than that of Bi3Se4 (193.6 F g-1) at 5 mV s-1. This result may be attributed to the fact that Bi2Se3 nanoplates possess more active electrochemical surfaces for the reversible surface redox reactions owing to their planar quintuple stacked layers (septuple layers for Bi3Se4). To meet the demands of electronic skin, we used a novel flexible annular interdigital structure electrode to support the all-solid-state micro-supercapacitors (AMSCs). The Bi2Se3 AMSC device delivers a much better supercapacitor performance, exhibits a large stack capacitance of 89.5 F cm-3 at 20 mV s-1 (Bi3Se4: 79.1 F cm-3), a high energy density of 17.9 mWh cm-3 and a high power density of 18.9 W cm-3. The bismuth selenides also exhibit good cycle stability, with 95.5% retention after 1000 c for Bi2Se3 (Bi3Se4:90.3%). Clearly, Bi2Se3 nanoplates can be promising electrode materials for flexible annular interdigital AMSCs.

BiRd (clarithromycin, lenalidomide, dexamethasone): an update on long-term lenalidomide therapy in previously untreated patients with multiple myeloma.

Science.gov (United States)

Rossi, Adriana; Mark, Tomer; Jayabalan, David; Christos, Paul; Zafar, Faiza; Pekle, Karen; Pearse, Roger; Chen-Kiang, Selina; Coleman, Morton; Niesvizky, Ruben

2013-03-14

The combination of clarithromycin, lenalidomide, and dexamethasone (BiRd) was evaluated as therapy for treatment-naive symptomatic multiple myeloma (MM), with overall response at 2 years of 90%. We reviewed the long-term follow-up of initial BiRd therapy. Seventy-two patients were given dexamethasone 40 mg weekly, clarithromycin 500 mg twice daily, and lenalidomide 25 mg daily on days 1 to 21 of a 28-day cycle. After a median follow-up of 6.6 years, overall response rates were 93%, with a very good partial response or better of 68%. Median progression-free survival was 49 months. Evaluation for the development of second primary malignancies (SPMs) was conducted, and no increase in incidence was noted in our cohort of patients who received frontline immunomodulatory therapy. BiRd remains a highly potent and safe regimen for frontline therapy in patients with MM without apparent increase in risk of SPMs. This trial was registered at www.clinicaltrials.gov as #NCT00151203.

Synthesis, structural and spectroscopic properties of acentric triple molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3}

Energy Technology Data Exchange (ETDEWEB)

Savina, A.A. [Laboratory of Oxide Systems, Baikal Institute of Nature Management, SB RAS, Ulan-Ude 670047 (Russian Federation); Department of Chemistry, Buryat State University, Ulan-Ude 670000 (Russian Federation); Atuchin, V.V., E-mail: atuchin@isp.nsc.ru [Laboratory of Optical Materials and Structures, Rzhanov Institute of Semiconductor Physics, SB RAS, Novosibirsk 630090 (Russian Federation); Functional Electronics Laboratory, Tomsk State University, Tomsk 634050 (Russian Federation); Laboratory of Semiconductor and Dielectric Materials, Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Solodovnikov, S.F. [Laboratory of Crystal Chemistry, Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Department of Natural Sciences, Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Solodovnikova, Z.A. [Laboratory of Crystal Chemistry, Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Krylov, A.S. [Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Maximovskiy, E.A. [Laboratory of Epitaxial Layers, Nikolaev Institute of Inorganic Chemistry, SB RAS, Novosibirsk 630090 (Russian Federation); Laboratory of Research Methods of Composition and Structure of Functional Materials, Novosibirsk State University, Novosibirsk 630090 (Russian Federation); Molokeev, M.S. [Laboratory of Crystal Structure, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Oreshonkov, A.S [Laboratory of Molecular Spectroscopy, Kirensky Institute of Physics, SB RAS, Krasnoyarsk 660036 (Russian Federation); Department of Photonics and Laser Technology, Siberian Federal University, Krasnoyarsk 660079 (Russian Federation); Pugachev, A.M. [Laboratory of Condenced Matter Spectroscopy, Institute of Automation and Electrometry, SB RAS, Novosibirsk 90, 630090 (Russian Federation); and others

2015-05-15

New ternary molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is synthesized in the system Na{sub 2}MoO{sub 4}–Cs{sub 2}MoO{sub 4}–Bi{sub 2}(MoO{sub 4}){sub 3}. The structure of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} of a new type is determined in noncentrosymmetric space group R3c, a=10.6435(2), c=40.9524(7) Å, V=4017.71(13) Å{sup 3}, Z=12 in anisotropic approximation for all atoms taking into account racemic twinning. The structure is completely ordered, Mo atoms are tetrahedrally coordinated, Bi(1) and Bi(2) atoms are in octahedra, and Na(1) and Na(2) atoms have a distorted trigonal prismatic coordination. The Cs(1) and Cs(2) atoms are in the framework cavities with coordination numbers 12 and 10, respectively. No phase transitions were found in Cs{sub 2}NaBi(MoO{sub 4}){sub 3} up to the melting point at 826 K. The compound shows an SHG signal, I{sub 2w}/I{sub 2w}(SiO{sub 2})=5 estimated by the powder method. The vibrational properties are evaluated by Raman spectroscopy, and 26 narrow lines are measured. - Graphical abstract: - Highlights: • The crystal structure of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is defined. • The molybdate Cs{sub 2}NaBi(MoO{sub 4}){sub 3} is stable up to melting point at 826 K. • Vibrational properties of Cs{sub 2}NaBi(MoO{sub 4}){sub 3} are evaluated by Raman spectroscopy.

Enhanced photosensitization process induced by the p–n junction of Bi2O2CO3/BiOCl heterojunctions on the degradation of rhodamine B

International Nuclear Information System (INIS)

Lu, Haijing; Xu, Lingling; Wei, Bo; Zhang, Mingyi; Gao, Hong; Sun, Wenjun

2014-01-01

Herein, we report the enhanced photosensitization process in the nanosheet Bi 2 O 2 CO 3 /BiOCl heterojunctions photocatalyst. The combined XRD, FT-IR and Raman results have confirmed the co-existence of Bi 2 O 2 CO 3 and BiOCl phases in the composites. Although both Bi 2 O 2 CO 3 and BiOCl are wide bandgap semiconductors, the composites showed an unexpectedly high catalytic activity in decomposing RhB (rhodamine B) aqueous solution under visible light irradiation. The mechanism of enhanced photocatalytic activity was ascribed to the inner electric field formed in the Bi 2 O 2 CO 3 /BiOCl p–n junction.

High-temperature abnormal behavior of resistivities for Bi-In melts

International Nuclear Information System (INIS)

Xi Yun; Zu Fangqiu; Li Xianfen; Yu Jin; Liu Lanjun; Li Qiang; Chen Zhihao

2004-01-01

The patterns of electrical resistivities versus temperature in large temperature range have been studied, using the D.C. four-probe method, for liquid Bi-In alloys (Bi-In(33 wt%), Bi-In(38 wt%), Bi-In(50.5 wt%), Bi-In(66 wt%)). The clear turning point of each resistivity-temperature curves of the liquid Bi-In alloys is observed at the temperature much above the melting point, in which temperature range the resistivity-temperature coefficient increases rapidly. Except for the turning temperature range, the resistivities of Bi-In alloys increase linearly with temperature. Because resistivity is sensitive to the structure, this experiment shows the structural transition in Bi-In melts at the temperature much higher than the liquidus. And it is suggested that there are different Bi-In short-range orderings in different Bi-In melts, so the resistivity-temperature curves have the turns at different temperatures and the resistivity-temperature coefficients are also different

LDR segmented mirror technology assessment study

Science.gov (United States)

Krim, M.; Russo, J.

1983-01-01

In the mid-1990s, NASA plans to orbit a giant telescope, whose aperture may be as great as 30 meters, for infrared and sub-millimeter astronomy. Its primary mirror will be deployed or assembled in orbit from a mosaic of possibly hundreds of mirror segments. Each segment must be shaped to precise curvature tolerances so that diffraction-limited performance will be achieved at 30 micron (nominal operating wavelength). All panels must lie within 1 micron on a theoretical surface described by the optical precipitation of the telescope's primary mirror. To attain diffraction-limited performance, the issues of alignment and/or position sensing, position control of micron tolerances, and structural, thermal, and mechanical considerations for stowing, deploying, and erecting the reflector must be resolved. Radius of curvature precision influences panel size, shape, material, and type of construction. Two superior material choices emerged: fused quartz (sufficiently homogeneous with respect to thermal expansivity to permit a thin shell substrate to be drape molded between graphite dies to a precise enough off-axis asphere for optical finishing on the as-received a segment) and a Pyrex or Duran (less expensive than quartz and formable at lower temperatures). The optimal reflector panel size is between 1-1/2 and 2 meters. Making one, two-meter mirror every two weeks requires new approaches to manufacturing off-axis parabolic or aspheric segments (drape molding on precision dies and subsequent finishing on a nonrotationally symmetric dependent machine). Proof-of-concept developmental programs were identified to prove the feasibility of the materials and manufacturing ideas.

Quantification of esophageal wall thickness in CT using atlas-based segmentation technique

Science.gov (United States)

Wang, Jiahui; Kang, Min Kyu; Kligerman, Seth; Lu, Wei

2015-03-01

Esophageal wall thickness is an important predictor of esophageal cancer response to therapy. In this study, we developed a computerized pipeline for quantification of esophageal wall thickness using computerized tomography (CT). We first segmented the esophagus using a multi-atlas-based segmentation scheme. The esophagus in each atlas CT was manually segmented to create a label map. Using image registration, all of the atlases were aligned to the imaging space of the target CT. The deformation field from the registration was applied to the label maps to warp them to the target space. A weighted majority-voting label fusion was employed to create the segmentation of esophagus. Finally, we excluded the lumen from the esophagus using a threshold of -600 HU and measured the esophageal wall thickness. The developed method was tested on a dataset of 30 CT scans, including 15 esophageal cancer patients and 15 normal controls. The mean Dice similarity coefficient (DSC) and mean absolute distance (MAD) between the segmented esophagus and the reference standard were employed to evaluate the segmentation results. Our method achieved a mean Dice coefficient of 65.55 ± 10.48% and mean MAD of 1.40 ± 1.31 mm for all the cases. The mean esophageal wall thickness of cancer patients and normal controls was 6.35 ± 1.19 mm and 6.03 ± 0.51 mm, respectively. We conclude that the proposed method can perform quantitative analysis of esophageal wall thickness and would be useful for tumor detection and tumor response evaluation of esophageal cancer.

Cavity contour segmentation in chest radiographs using supervised learning and dynamic programming

International Nuclear Information System (INIS)

Maduskar, Pragnya; Hogeweg, Laurens; Sánchez, Clara I.; Ginneken, Bram van; Jong, Pim A. de; Peters-Bax, Liesbeth; Dawson, Rodney; Ayles, Helen

2014-01-01

Purpose: Efficacy of tuberculosis (TB) treatment is often monitored using chest radiography. Monitoring size of cavities in pulmonary tuberculosis is important as the size predicts severity of the disease and its persistence under therapy predicts relapse. The authors present a method for automatic cavity segmentation in chest radiographs. Methods: A two stage method is proposed to segment the cavity borders, given a user defined seed point close to the center of the cavity. First, a supervised learning approach is employed to train a pixel classifier using texture and radial features to identify the border pixels of the cavity. A likelihood value of belonging to the cavity border is assigned to each pixel by the classifier. The authors experimented with four different classifiers:k-nearest neighbor (kNN), linear discriminant analysis (LDA), GentleBoost (GB), and random forest (RF). Next, the constructed likelihood map was used as an input cost image in the polar transformed image space for dynamic programming to trace the optimal maximum cost path. This constructed path corresponds to the segmented cavity contour in image space. Results: The method was evaluated on 100 chest radiographs (CXRs) containing 126 cavities. The reference segmentation was manually delineated by an experienced chest radiologist. An independent observer (a chest radiologist) also delineated all cavities to estimate interobserver variability. Jaccard overlap measure Ω was computed between the reference segmentation and the automatic segmentation; and between the reference segmentation and the independent observer's segmentation for all cavities. A median overlap Ω of 0.81 (0.76 ± 0.16), and 0.85 (0.82 ± 0.11) was achieved between the reference segmentation and the automatic segmentation, and between the segmentations by the two radiologists, respectively. The best reported mean contour distance and Hausdorff distance between the reference and the automatic segmentation were

Cavity contour segmentation in chest radiographs using supervised learning and dynamic programming

Energy Technology Data Exchange (ETDEWEB)

Maduskar, Pragnya, E-mail: pragnya.maduskar@radboudumc.nl; Hogeweg, Laurens; Sánchez, Clara I.; Ginneken, Bram van [Diagnostic Image Analysis Group, Radboud University Medical Center, Nijmegen, 6525 GA (Netherlands); Jong, Pim A. de [Department of Radiology, University Medical Center Utrecht, 3584 CX (Netherlands); Peters-Bax, Liesbeth [Department of Radiology, Radboud University Medical Center, Nijmegen, 6525 GA (Netherlands); Dawson, Rodney [University of Cape Town Lung Institute, Cape Town 7700 (South Africa); Ayles, Helen [Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, London WC1E 7HT (United Kingdom)

2014-07-15

Purpose: Efficacy of tuberculosis (TB) treatment is often monitored using chest radiography. Monitoring size of cavities in pulmonary tuberculosis is important as the size predicts severity of the disease and its persistence under therapy predicts relapse. The authors present a method for automatic cavity segmentation in chest radiographs. Methods: A two stage method is proposed to segment the cavity borders, given a user defined seed point close to the center of the cavity. First, a supervised learning approach is employed to train a pixel classifier using texture and radial features to identify the border pixels of the cavity. A likelihood value of belonging to the cavity border is assigned to each pixel by the classifier. The authors experimented with four different classifiers:k-nearest neighbor (kNN), linear discriminant analysis (LDA), GentleBoost (GB), and random forest (RF). Next, the constructed likelihood map was used as an input cost image in the polar transformed image space for dynamic programming to trace the optimal maximum cost path. This constructed path corresponds to the segmented cavity contour in image space. Results: The method was evaluated on 100 chest radiographs (CXRs) containing 126 cavities. The reference segmentation was manually delineated by an experienced chest radiologist. An independent observer (a chest radiologist) also delineated all cavities to estimate interobserver variability. Jaccard overlap measure Ω was computed between the reference segmentation and the automatic segmentation; and between the reference segmentation and the independent observer's segmentation for all cavities. A median overlap Ω of 0.81 (0.76 ± 0.16), and 0.85 (0.82 ± 0.11) was achieved between the reference segmentation and the automatic segmentation, and between the segmentations by the two radiologists, respectively. The best reported mean contour distance and Hausdorff distance between the reference and the automatic segmentation were

Parameter-space metric of semicoherent searches for continuous gravitational waves

International Nuclear Information System (INIS)

Pletsch, Holger J.

2010-01-01

Continuous gravitational-wave (CW) signals such as emitted by spinning neutron stars are an important target class for current detectors. However, the enormous computational demand prohibits fully coherent broadband all-sky searches for prior unknown CW sources over wide ranges of parameter space and for yearlong observation times. More efficient hierarchical ''semicoherent'' search strategies divide the data into segments much shorter than one year, which are analyzed coherently; then detection statistics from different segments are combined incoherently. To optimally perform the incoherent combination, understanding of the underlying parameter-space structure is requisite. This problem is addressed here by using new coordinates on the parameter space, which yield the first analytical parameter-space metric for the incoherent combination step. This semicoherent metric applies to broadband all-sky surveys (also embedding directed searches at fixed sky position) for isolated CW sources. Furthermore, the additional metric resolution attained through the combination of segments is studied. From the search parameters (sky position, frequency, and frequency derivatives), solely the metric resolution in the frequency derivatives is found to significantly increase with the number of segments.

High-pressure studies of superconductivity in BiO0. 75F0. 25BiS2

Indian Academy of Sciences (India)

). We have investigated the effect of pressure on magnetization measurements. Our studies suggest improved superconducting properties in polycrystalline samples of BiO 0.75 F 0.25 BiS 2 . The Tc in our sample is 5.3 K, at ambient pressure, ...

Potential barrier behavior in BiCuVOX materials Comportamento da barreira de potencial em materiais BiCuVOX

Directory of Open Access Journals (Sweden)

S. M. Gheno

2011-12-01

Full Text Available The BiMeVOX materials appear being high attractive for applications at low temperatures when the ionic conductivity is the determining parameter. The occurrence of many types substitution was confirmed for numerous Me ions, but the greatest interest have been focused on the BiCuVOX materials. The objective of this study was to image the potential barriers in BiCuVOX. The sample was sintered for 4 h at 750 °C and the results show that the high density compound can be obtained. Simultaneously, topography and electric force microscopy (EFM images are viewed side-by-side. EFM experiments were performed and the results show the maps of the electric field distribution on the surface of BiCuVOX. The formation of potential barrier was observed and the width and intensity were measured.Materiais do tipo BiMeVOX são muito atrativos para aplicações em baixas temperaturas quando a condutividade iônica for o parâmetro determinante. A ocorrência de muitos tipos de substituições foi confirmada para numerosos íons Me, dentre os quais, existe um grande interesse no estudo de materiais BiCuVOX. O objetivo deste estudo foi realizar o imageamento das barreiras de potencial em uma amostra de material BiCuVOX. A amostra foi sinterizada 4 h a 750 °C e apresentou alta densidade. Imagens da superfície topográfica e de microscopia de força elétrica (EFM foram obtidas simultaneamente em um microscópio de varredura por sonda. Os experimentos EFM mostraram um mapa da distribuição do campo elétrico na superfície do material BiCuVOx. A formação da barreira de potencial foi observada e tanto a largura quanto a altura foram medidas.

Gd-substituted Bi-2223 superconductor

Indian Academy of Sciences (India)

The effects of gadolinium doping at calcium site on the normal and super- conducting properties of Bi-2223 system were ... quantities of the metal oxides and the carbonates were taken and thoroughly mixed. The calcination of the mixture after .... Therefore, Gd has higher solubility in (BiPb)-2223 as compared to Pr, and is, ...

Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2): New one-dimensional Bi-coordination materials—Reversible hydration and topotactic decomposition to α-Bi2O3

Science.gov (United States)

Jeon, Hye Rim; Lee, Dong Woo; Ok, Kang Min

2012-03-01

Two one-dimensional bismuth-coordination materials, Bi[NC5H3(CO2)2](OH2)xF (x=1 and 2), have been synthesized by hydrothermal reactions using Bi2O3, 2,6-NC5H3(CO2H)2, HF, and water at 180 °C. Structures of the two materials were determined by single-crystal X-ray diffraction. Although they have different crystal structures, both Bi-organic materials shared a common structural motif, a one-dimensional chain structure consisting of Bi3+ cations and pyridine dicarboxylate linkers. Detailed structural analyses include infrared spectroscopy, thermogravimetric analysis, and reversible hydration reactions for the coordinated water molecules were reported. Also, thermal decomposition of the rod-shaped Bi[NC5H3(CO2)2](OH2)F single crystals at 800 °C led to α-Bi2O3 that maintained the same morphology of the original crystals.

The highly enhanced visible light photocatalytic degradation of gaseous o-dichlorobenzene through fabricating like-flowers BiPO{sub 4}/BiOBr p-n heterojunction composites

Energy Technology Data Exchange (ETDEWEB)

Zou, Xuejun [Department of Environmental Science and Technology, Dalian Nationalities University, Dalian, 116600 (China); Dong, Yuying, E-mail: dongy@dlnu.edu.cn [Department of Environmental Science and Technology, Dalian Nationalities University, Dalian, 116600 (China); Zhang, Xiaodong, E-mail: fatzhxd@126.com [Environment and Low-Carbon Research Center, School of Environment and Architecture, University of Shanghai for Science and Technology, Shanghai, 200093 (China); Cui, Yubo; Ou, Xiaoxia [Department of Environmental Science and Technology, Dalian Nationalities University, Dalian, 116600 (China); Qi, Xiaohui [College of Life Science, Dalian Nationalities University, Dalian, 116600 (China)

2017-01-01

Highlights: • Like-flowers BiPO{sub 4}/BiOBr was fabricated by mixing in solvent method. • o-Dichlorobenzene removal efficiency was 53.6% using BiPO{sub 4}/BiOBr. • The p–n junction improved o-dichlorobenzene degradation activity. - Abstract: In this paper, in order to enhance photo-induced electron-hole pairs separation of BiOBr, flowers-like BiPO{sub 4}/BiOBr p-n heterojunction composites was fabricated by a mixing in solvent method. The as-prepared samples were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), high resolution transmission electron microscopy (HRTEM), UV–vis absorption spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and N{sub 2} adsorption-desorption. Meanwhile, their photocatalytic properties were investigated by the degradation of gaseous o-dichlorobenzene under visible light irradiation. Due to its strong adsorption capacity and the formation of p-n heterojunction, compared with BiPO{sub 4} and BiOBr, the BiPO{sub 4}/BiOBr composites showed higher photocatalytic activity in the degradation of gaseous o-DCB under visible light. Among them, 2% BiPO{sub 4}/BiOBr showed the maximum value of the activity, whose degradation rate was about 2.6 times as great as the pure BiOBr. Furthermore, the OH· was confirmed the main active species during the photocatalytic process by the trapping experiments. The outstanding performance indicated that the photocatalysts could be applied to air purification for chlorinated volatile organic compound.

Segmentation strategies for the irradiated and tritium contaminated PPPL TFTR

International Nuclear Information System (INIS)

Walton, G.R.; Spampinato, P.T.

1995-01-01

The Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory is scheduled to complete its final experiments in the Fall of 1995. As a result, the TFTR will be activated and tritium contaminated. After the experiments are complete, the TFTR will undergo Shutdown and Removal (S and R). The space vacated by the TFTR will be used for a new test reactor, the Tokamak Physics Experiment (TPX). Remote methods may be required to remove components and to segment the Vacuum Vessel. The TFTR has been studied to determine alternatives for the segmentation of the Vacuum Vessel from the inside (In-Vessel). The methodology to determine suitable strategies to segment the Vacuum Vessel from In-Vessel included several areas of concentration. These areas were segmentation locations, cutting/removal technologies, pros and cons, and cutting/removal technology delivery systems. The segmentation locations for easiest implementation and minimal steps in cutting and removal have been identified. Each of these will also achieve the baseline for packaging and shipment. The methods for cutting and removal of components were determined. In addition, the delivery systems were conceptualized

Segmentation strategies for the irradiated and tritium contaminated PPPL TFTR

Energy Technology Data Exchange (ETDEWEB)

Walton, G.R. [Princeton Univ., NJ (United States). Plasma Physics Lab.; Litka, T.J. [Advanced Consulting Group, Inc., Chicago, IL (United States); Spampinato, P.T. [RHD Consultants, Inc., Princeton, NJ (United States)

1995-02-09

The Tokamak Fusion Test Reactor (TFTR) at Princeton Plasma Physics Laboratory is scheduled to complete its final experiments in the Fall of 1995. As a result, the TFTR will be activated and tritium contaminated. After the experiments are complete, the TFTR will undergo Shutdown and Removal (S and R). The space vacated by the TFTR will be used for a new test reactor, the Tokamak Physics Experiment (TPX). Remote methods may be required to remove components and to segment the Vacuum Vessel. The TFTR has been studied to determine alternatives for the segmentation of the Vacuum Vessel from the inside (In-Vessel). The methodology to determine suitable strategies to segment the Vacuum Vessel from In-Vessel included several areas of concentration. These areas were segmentation locations, cutting/removal technologies, pros and cons, and cutting/removal technology delivery systems. The segmentation locations for easiest implementation and minimal steps in cutting and removal have been identified. Each of these will also achieve the baseline for packaging and shipment. The methods for cutting and removal of components were determined. In addition, the delivery systems were conceptualized.

Statistical shape (ASM) and appearance (AAM) models for the segmentation of the cerebellum in fetal ultrasound

Science.gov (United States)

Reyes López, Misael; Arámbula Cosío, Fernando

2017-11-01

The cerebellum is an important structure to determine the gestational age of the fetus, moreover most of the abnormalities it presents are related to growth disorders. In this work, we present the results of the segmentation of the fetal cerebellum applying statistical shape and appearance models. Both models were tested on ultrasound images of the fetal brain taken from 23 pregnant women, between 18 and 24 gestational weeks. The accuracy results obtained on 11 ultrasound images show a mean Hausdorff distance of 6.08 mm between the manual segmentation and the segmentation using active shape model, and a mean Hausdorff distance of 7.54 mm between the manual segmentation and the segmentation using active appearance model. The reported results demonstrate that the active shape model is more robust in the segmentation of the fetal cerebellum in ultrasound images.

Stability of multi-objective bi-level linear programming problems under fuzziness

Directory of Open Access Journals (Sweden)

Abo-Sinna Mahmoud A.

2013-01-01

Full Text Available This paper deals with multi-objective bi-level linear programming problems under fuzzy environment. In the proposed method, tentative solutions are obtained and evaluated by using the partial information on preference of the decision-makers at each level. The existing results concerning the qualitative analysis of some basic notions in parametric linear programming problems are reformulated to study the stability of multi-objective bi-level linear programming problems. An algorithm for obtaining any subset of the parametric space, which has the same corresponding Pareto optimal solution, is presented. Also, this paper established the model for the supply-demand interaction in the age of electronic commerce (EC. First of all, the study uses the individual objectives of both parties as the foundation of the supply-demand interaction. Subsequently, it divides the interaction, in the age of electronic commerce, into the following two classifications: (i Market transactions, with the primary focus on the supply demand relationship in the marketplace; and (ii Information service, with the primary focus on the provider and the user of information service. By applying the bi-level programming technique of interaction process, the study will develop an analytical process to explain how supply-demand interaction achieves a compromise or why the process fails. Finally, a numerical example of information service is provided for the sake of illustration.

Malignant pleural mesothelioma segmentation for photodynamic therapy planning.

Science.gov (United States)

Brahim, Wael; Mestiri, Makram; Betrouni, Nacim; Hamrouni, Kamel

2018-04-01

Medical imaging modalities such as computed tomography (CT) combined with computer-aided diagnostic processing have already become important part of clinical routine specially for pleural diseases. The segmentation of the thoracic cavity represents an extremely important task in medical imaging for different reasons. Multiple features can be extracted by analyzing the thoracic cavity space and these features are signs of pleural diseases including the malignant pleural mesothelioma (MPM) which is the main focus of our research. This paper presents a method that detects the MPM in the thoracic cavity and plans the photodynamic therapy in the preoperative phase. This is achieved by using a texture analysis of the MPM region combined with a thoracic cavity segmentation method. The algorithm to segment the thoracic cavity consists of multiple stages. First, the rib cage structure is segmented using various image processing techniques. We used the segmented rib cage to detect feature points which represent the thoracic cavity boundaries. Next, the proposed method segments the structures of the inner thoracic cage and fits 2D closed curves to the detected pleural cavity features in each slice. The missing bone structures are interpolated using a prior knowledge from manual segmentation performed by an expert. Next, the tumor region is segmented inside the thoracic cavity using a texture analysis approach. Finally, the contact surface between the tumor region and the thoracic cavity curves is reconstructed in order to plan the photodynamic therapy. Using the adjusted output of the thoracic cavity segmentation method and the MPM segmentation method, we evaluated the contact surface generated from these two steps by comparing it to the ground truth. For this evaluation, we used 10 CT scans with pathologically confirmed MPM at stages 1 and 2. We obtained a high similarity rate between the manually planned surface and our proposed method. The average value of Jaccard index

Investigation of the phase formation and dielectric properties of Bi{sub 7}Ta{sub 3}O{sub 18}

Energy Technology Data Exchange (ETDEWEB)

Chon, M.P. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Tan, K.B., E-mail: tankb@science.upm.my [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Khaw, C.C. [Department of Mechanical and Material Engineering, Faculty of Engineering and Science, Universiti Tunku Abdul Rahman, 53300 Setapak, Kuala Lumpur (Malaysia); Zainal, Z.; Taufiq Yap, Y.H. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Chen, S.K. [Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia); Tan, P.Y. [Department of Chemistry, Faculty of Science, Universiti Putra Malaysia, 43400 Serdang, Selangor (Malaysia)

2014-03-25

Highlights: • Synthesis condition of Bi{sub 7}TaO{sub 3}O{sub 18} had been determined. • Recombination of intermediate BiTaO{sub 4} and Bi{sub 3}TaO{sub 7} phases are required for the Bi{sub 7}TaO{sub 3}O{sub 18} phase formation. • Stable material as confirmed by thermal and structural analyses. • Typical ferroelectric showing high dielectric constants and low losses. • Resonance and thermal activated polarisation processes are responsible for the excellent dielectric characteristic. -- Abstract: Polycrystalline Bi{sub 7}Ta{sub 3}O{sub 18} was synthesised at the firing temperature of 950 °C over 18 h via conventional solid state method. It crystallised in a monoclinic system with space group C2/m, Z = 4 similar to that reported diffraction pattern in the Inorganic Crystal Structure Database (ICSD), 1-89-6647. The refined lattice parameters were a = 34.060 (3) Å, b = 7.618 (9) Å, c = 6.647 (6) Å with α = γ = 90° and β = 109.210 (7), respectively. The intermediate phase was predominantly in high-symmetry cubic structure below 800 °C and finally evolved into a low-symmetry monoclinic structured, Bi{sub 7}Ta{sub 3}O{sub 18} at 950 °C. The sample contained grains of various shapes with different orientations in the size ranging from 0.33–22.70 μm. The elemental analysis showed the sample had correct stoichiometry with negligible Bi{sub 2}O{sub 3} loss. Bi{sub 7}Ta{sub 3}O{sub 18} was thermally stable and it exhibited a relatively high relative permittivity, 241 and low dielectric loss, 0.004 at room temperature, ∼30 °C and frequency of 1 MHz.

Electron diffraction study of the sillenites Bi12SiO20, Bi25FeO39 and Bi25InO39: Evidence of short-range ordering of oxygen-vacancies in the trivalent sillenites

Directory of Open Access Journals (Sweden)

Craig A. Scurti

2014-08-01

Full Text Available We present an electron diffraction study of three sillenites, Bi12SiO20, Bi25FeO39, and Bi25InO39 synthesized using the solid-state method. We explore a hypothesis, inspired by optical studies in the literature, that suggests that trivalent sillenites have additional disorder not present in the tetravalent compounds. Electron diffraction patterns of Bi25FeO39 and Bi25InO39 show streaks that confirm deviations from the ideal sillenite structure. Multi-slice simulations of electron-diffraction patterns are presented for different perturbations to the sillenite structure - partial substitution of the M site by Bi3+, random and ordered oxygen-vacancies, and a frozen-phonon model. Although comparison of experimental data to simulations cannot be conclusive, we consider the streaks as evidence of short-range ordered oxygen-vacancies.

The effect of FR enhancement in reactive ion beam sputtered Bi, Gd, Al-substituted iron- garnets: Bi2O3 nanocomposite films

OpenAIRE

Berzhansky, V.; Shaposhnikov, A.; Karavainikov, A.; Prokopov, A.; Mikhailova, T.; Lukienko, I.; Kharchenko, Yu.; Miloslavskaya, O.; Kharchenko, N.

2012-01-01

The effect of considerable Faraday rotation (FR) and figure of merit (Q) enhancement in Bi, Gd, Al-substituted iron garnets: Bi2O3 nano-composite films produced by separate reactive ion beam sputtered Bi:YIG and Bi2O3 films was found. It reached threefold enhancement of the FR and twofold of the Q one on GGG substrates.

Overexpression of BiP in tobacco alleviates endoplasmic reticulum stress

NARCIS (Netherlands)

Leborgne-Castel, N.; Jelitto- Dooren, E.P.W.M. van; Crofts, A.J.; Denecke, J.

1999-01-01

To study the role of the lumenal binding protein (BiP) in the transport and secretion of proteins, we have produced plants with altered BiP levels. Transgenic plants overexpressing BiP showed dramatically increased BiP mRNA levels but only a modest increase in BiP protein levels. The presence of

Bi:Ge substitution - its effect on the structural and electrical properties of the Bi2212 superconductor

International Nuclear Information System (INIS)

Saligan, P.P.

1997-03-01

The critical temperature determined from dc resistance and ac magnetic susceptibility measurements, and the coherence length obtained from the of fluctuation conductivity of polycrystalline Bi 2-x Ge x Sr 2 CaCu 2 O 8 +δ were studied. The effect of sample quality was also studied by making two kinds of pellet samples: (1) by conventional sintering process and (2) by conventional sintering process followed annealing at high temperature. The rough phase diagram of Bi 2-x Ge x Sr 2 CaCu 2 O 8 +δ was constructed and it was found that from x=0 to x=0.3 a predominantly Bi2212 phase can be obtained. The critical temperature of the unsubstituted Bi 2 Sr 2 CaCu 2 O 8 +δ is sensitive to the cold press and anneal method. The resistive transition T c based on the maximum dR(T)dT of the as-sintered Bi 2 Sr 2 CaCu 2 O 8 +δ is about 74 K. The resistive T c of the cold-pressed-annealed samples either (1) remain near 74 K or (2) increase to approximately 85 K or (3) show two values at about 74 K and 85 K. A structural relaxation is observed in the Bi 2-x Ge x Sr 2 CaCu 2 O 8 +δ the c-axis decreases with increasing x and the a-axis increases at x=0.1 then settles back to its unsubstituted value at higher x. The as-sintered samples show an increasing resistive T c with x, 74 K for x=0 and 79 K for x>0. The resistive T c 's of the cold-pressed-annealed samples are almost independent of x, 85 K for x=0 and 87 K for x>0. The increase in the magnetic critical temperature induced by the cold press and anneal method is considerably larger compared to the increase in the resistive critical temperature, independent of the Bi:Ge substitution. An analysis of fluctuation conductivity just above T c using the Aslamasov-Larkin model for two-dimensional superconductors and the Lawrence-Doniach model for layered superconductors was done. The Aslamasov-Larkin model gives the thickness of the two dimensional superconductor to be ∼34 A also independent of the Bi:Ge substitution. The Lawrence

Multi-Segment Radius Measurement Using an Absolute Distance Meter Through a Null Assembly

Science.gov (United States)

Merle, Cormic; Wick, Eric; Hayden, Joseph

2011-01-01

This system was one of the test methods considered for measuring the radius of curvature of one or more of the 18 segmented mirrors that form the 6.5 m diameter primary mirror (PM) of the James Webb Space Telescope (JWST). The assembled telescope will be tested at cryogenic temperatures in a 17-m diameter by 27-m high vacuum chamber at the Johnson Space Center. This system uses a Leica Absolute Distance Meter (ADM), at a wavelength of 780 nm, combined with beam-steering and beam-shaping optics to make a differential distance measurement between a ring mirror on the reflective null assembly and individual PM segments. The ADM is located inside the same Pressure-Tight Enclosure (PTE) that houses the test interferometer. The PTE maintains the ADM and interferometer at ambient temperature and pressure so that they are not directly exposed to the telescope s harsh cryogenic and vacuum environment. This system takes advantage of the existing achromatic objective and reflective null assembly used by the test interferometer to direct four ADM beamlets to four PM segments through an optical path that is coincident with the interferometer beam. A mask, positioned on a linear slide, contains an array of 1.25 mm diameter circular subapertures that map to each of the 18 PM segments as well as six positions around the ring mirror. A down-collimated 4 mm ADM beam simultaneously covers 4 adjacent PM segment beamlets and one ring mirror beamlet. The radius, or spacing, of all 18 segments can be measured with the addition of two orthogonally-oriented scanning pentaprisms used to steer the ADM beam to any one of six different sub-aperture configurations at the plane of the ring mirror. The interferometer beam, at a wavelength of 687 nm, and the ADM beamlets, at a wavelength of 780 nm, pass through the objective and null so that the rays are normally incident on the parabolic PM surface. After reflecting off the PM, both the ADM and interferometer beams return to their respective

Bi-amalgamations subject to the arithmetical property

OpenAIRE

Kabbaj, S.; Mahdou, N.; Moutui, M. A. S.

2016-01-01

This paper establishes necessary and sufficient conditions for a bi-amalgamation to inherit the arithmetical property, with applications on the weak global dimension and transfer of the semihereditary property. The new results compare to previous works carried on various settings of duplications and amalgamations, and capitalize on recent results on bi-amalgamations. All results are backed with new and illustrative examples arising as bi-amalgamations.

BiOCl nanowire with hierarchical structure and its Raman features

International Nuclear Information System (INIS)

Tian Ye; Guo Chuanfei; Guo Yanjun; Wang Qi; Liu Qian

2012-01-01

BiOCl is a promising V-VI-VII-compound semiconductor with excellent optical and electrical properties, and has great potential applications in photo-catalysis, photoelectric, etc. We successfully synthesize BiOCl nanowire with a hierarchical structure by combining wet etch (top-down) with liquid phase crystal growth (bottom-up) process, opening a novel method to construct ordered bismuth-based nanostructures. The morphology and lattice structures of Bi nanowires, β-Bi 2 O 3 nanowires and BiOCl nanowires with the hierarchical structure are investigated by scanning electron microscope (SEM) and transition electron microscope (TEM). The formation mechanism of such ordered BiOCl hierarchical structure is considered to mainly originate from the highly preferred growth, which is governed by the lattice match between (1 1 0) facet of BiOCl and (2 2 0) or (0 0 2) facet of β-Bi 2 O 3 . A schematic model is also illustrated to depict the formation process of the ordered BiOCl hierarchical structure. In addition, Raman properties of the BiOCl nanowire with the hierarchical structure are investigated deeply.

Segmented Aperture Interferometric Nulling Testbed (SAINT) II: component systems update

Science.gov (United States)

Hicks, Brian A.; Bolcar, Matthew R.; Helmbrecht, Michael A.; Petrone, Peter; Burke, Elliot; Corsetti, James; Dillon, Thomas; Lea, Andrew; Pellicori, Samuel; Sheets, Teresa; Shiri, Ron; Agolli, Jack; DeVries, John; Eberhardt, Andrew; McCabe, Tyler

2017-09-01

This work presents updates to the coronagraph and telescope components of the Segmented Aperture Interferometric Nulling Testbed (SAINT). The project pairs an actively-controlled macro-scale segmented mirror with the Visible Nulling Coronagraph (VNC) towards demonstrating capabilities for the future space observatories needed to directly detect and characterize a significant sample of Earth-sized worlds around nearby stars in the quest for identifying those which may be habitable and possibly harbor life. Efforts to improve the VNC wavefront control optics and mechanisms towards repeating narrowband results are described. A narrative is provided for the design of new optical components aimed at enabling broadband performance. Initial work with the hardware and software interface for controlling the segmented telescope mirror is also presented.

Composite cervical skin and cartilage flap provides a novel large airway substitute after long-segment tracheal resection.

Science.gov (United States)

Fabre, Dominique; Singhal, Sunil; De Montpreville, Vincent; Decante, Benoit; Mussot, Sacha; Chataigner, Olivier; Mercier, Olaf; Kolb, Frederic; Dartevelle, Philippe G; Fadel, Elie

2009-07-01

Airway replacement after long-segment tracheal resection for benign and malignant disease remains a challenging problem because of the lack of a substitute conduit. Ideally, an airway substitute should be well vascularized, rigid, and autologous to avoid infections, airway stenosis, and the need for immunosuppression. We report the development of an autologous tracheal substitute for long-segment tracheal resection that satisfies these criteria and demonstrates excellent short-term functional results in a large-animal study. Twelve adult pigs underwent long-segment (6 cm, 60% of total length) tracheal resection. Autologous costal cartilage strips measuring 6 cm x 2 mm were harvested from the chest wall and inserted at regular 0.5-cm intervals between dermal layers of a cervical skin flap. The neotrachea was then scaffolded by rotating the composite cartilage skin flap around a silicone stent measuring 6 cm in length and 1.4 cm in diameter. The neotrachea replaced the long segment of tracheal resection, and the donor flap site was closed with a double-Z plasty. Animals were killed at 1 week (group I, n = 4), 2 weeks (group II, n = 4), and 5 weeks (group III, n = 4). In group III the stent was removed 1 week before death. Viability of the neotrachea was monitored by means of daily flexible bronchoscopy and histologic examination at autopsy. Long-term morbidity and mortality were determined by monitoring weight gain, respiratory distress, and survival. There was no mortality during the study period. Weight gain was appropriate in all animals. Daily bronchoscopy and postmortem histologic evaluation confirmed excellent viability of the neotrachea. There was no evidence of suture-line dehiscence. Five animals had distal granulomas that were removed by using rigid bronchoscopy. In group III 1 animal had tracheomalacia, which was successfully managed by means of insertion of a silicon stent. Airway reconstruction with autologous cervical skin flaps scaffolded with costal

47 CFR 97.207 - Space station.

Science.gov (United States)

2010-10-01

... FCC. (c) The following frequency bands and segments are authorized to space stations: (1) The 17 m, 15... notifications to the International Bureau, FCC, Washington, DC 20554. (1) A pre-space notification within 30... risk of collision and a description of what measures the space station operator plans to take to avoid...

Perovskite BaBiO3 Transformed Layered BaBiO2.5 Crystals Featuring Unusual Chemical Bonding and Luminescence.

Science.gov (United States)

Li, Hong; Zhao, Qing; Liu, Bo-Mei; Zhang, Jun-Ying; Li, Zhi-Yong; Guo, Shao-Qiang; Ma, Ju-Ping; Kuroiwa, Yoshihiro; Moriyoshi, Chikako; Zheng, Li-Rong; Sun, Hong-Tao

2018-04-14

Engineering oxygen coordination environments of cations in oxides has received intense interest thanks to the opportunities for the discovery of novel oxides with unusual properties. Here we present the successful synthesis of stoichiometric layered BaBiO2.5 enabled by a non-topotactic phase transformation of perovskite BaBiO3. By analysing the synchrotron X-ray diffraction data using the maximum entropy method/Rietveld technique, we find that Bi forms unusual chemical bondings with four oxygen atoms, featuring one ionic bonding and three covalent bondings that results in an asymmetric coordination geometry. A broad range of photophysical characterizations reveal that this peculiar structure shows near-infrared luminescence differing from conventional Bi-bearing systems. Experimental and theoretical results lead us to propose the excitonic nature of luminescence. Our work highlights that synthesizing materials with uncommon Bi-O bonding and Bi coordination geometry provides a pathway to the discovery of systems with new functionalities. We envisage that this work could inspire interest for the exploration of a range of materials containing heavier p-block elements, offering prospects for the finding of systems with unusual properties. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

[Slit lamp optical coherence tomography study of anterior segment changes after phacoemulsification and foldable intraocular lens implantation].

Science.gov (United States)

Yan, Pi-song; Zhang, Zhen-ping; Lin, Hao-tian; Wu, Wen-jie; Bai, Ling

2009-09-01

To investigate quantitative changes of the anterior segment configuration after clear corneal incision phacoemulsification and foldable intraocular lens (IOL) implantation with slit-lamp-adapted optical coherence tomography (SL-OCT). In prospective consecutive case series, clear corneal incision phacoemulsification and foldable intraocular lens implantation were performed in 44 eyes of 40 patients. The changes of the anterior segment configuration were performed by SL-OCT before and 1 day, 1 week, 2 weeks and 1 month after surgery. SPSS 16.0 software was used to analyze statistical difference. For all patients, the central corneal thickness (CCT) and the incisional corneal thickness (ICT) increased significantly 1 day after surgery (CCT increased 99.59 microm, ICT increased 234.57 microm; P = 0.490). At 1 month, the CCT almost had returned to baseline, but the ICT had been thicker about 19.25 microm than baseline(P = 0.001). The measurements of ACD, AOD500, AOD750, TISA500, TISA750 also increased significantly 1 day after surgery. Although the ACD had no changes within 2 weeks (all P 0.05). The SL-OCT could impersonality and quantificationally evaluate the anterior segment changes induced by cataract surgery.

Spectral embedding based active contour (SEAC): application to breast lesion segmentation on DCE-MRI

Science.gov (United States)

Agner, Shannon C.; Xu, Jun; Rosen, Mark; Karthigeyan, Sudha; Englander, Sarah; Madabhushi, Anant

2011-03-01

Spectral embedding (SE), a graph-based manifold learning method, has previously been shown to be useful in high dimensional data classification. In this work, we present a novel SE based active contour (SEAC) segmentation scheme and demonstrate its applications in lesion segmentation on breast dynamic contrast enhance magnetic resonance imaging (DCE-MRI). In this work, we employ SE on DCE-MRI on a per voxel basis to embed the high dimensional time series intensity vector into a reduced dimensional space, where the reduced embedding space is characterized by the principal eigenvectors. The orthogonal eigenvector-based data representation allows for computation of strong tensor gradients in the spectrally embedded space and also yields improved region statistics that serve as optimal stopping criteria for SEAC. We demonstrate both analytically and empirically that the tensor gradients in the spectrally embedded space are stronger than the corresponding gradients in the original grayscale intensity space. On a total of 50 breast DCE-MRI studies, SEAC yielded a mean absolute difference (MAD) of 3.2+/-2.1 pixels and mean Dice similarity coefficient (DSC) of 0.74+/-0.13 compared to manual ground truth segmentation. An active contour in conjunction with fuzzy c-means (FCM+AC), a commonly used segmentation method for breast DCE-MRI, produced a corresponding MAD of 7.2+/-7.4 pixels and mean DSC of 0.58+/-0.32. In conjunction with a set of 6 quantitative morphological features automatically extracted from the SEAC derived lesion boundary, a support vector machine (SVM) classifier yielded an area under the curve (AUC) of 0.73, for discriminating between 10 benign and 30 malignant lesions; the corresponding SVM classifier with the FCM+AC derived morphological features yielded an AUC of 0.65.