A simple construction method for sequentially tidying up 2D online freehand sketches

This paper presents a novel constructive approach to sequentially tidying up 2D online freehand sketches for further 3D interpretation in a conceptual design system. Upon receiving a sketch stroke, the system first identifies it as a 2D primitive and then automatically infers its 2D geometric constraints related to previous 2D geometry (if any). Based on recognized 2D constraints, the identified geometry will be modified accordingly to meet its constraints. The modification is realized in one or two sequent geometric constructions in consistence with its degrees of freedom. This method can produce 2D configurations without iterative procedures to solve constraint equations. It is simple and easy to use for a real-time application. Several examples are tested and discussed

Simulation of the 2009 Harmanli fire (Bulgaria)

We use a coupled atmosphere-fire model to simulate a fire that occurred on August 14--17, 2009, in the Harmanli region, Bulgaria. Data was obtained from GIS and satellites imagery, and from standard atmospheric data sources. Fuel data was classified in the 13 Anderson categories. For correct fire behavior, the spatial resolution of the models needed to be fine enough to resolve the essential micrometeorological effects. The simulation results are compared to available incident data. The code runs faster than real time on a cluster. The model is available from openwfm.org and it extends WRF-Fire from WRF 3.3 release.Comment: 8 pages, 2 tables, 5 figures. 8th International Conference on Large-Scale Scientific Computations, June 6-10, 2011, Sozopol, Bulgari

Multifunctional Cotton Impregnated with Multilayer Chitosan/Lignin Nanocoating and Ag Nanoparticles

he demand for clothes with antimicrobial and UV protective properties is continually growing. In an attempt to develop a simple and efficient treatment for cotton fabrics, layer-by-layer deposition of chitosan and magnesium lignosulfonate followed by in situ synthesis of Ag nanoparticles (NPs) was performed. Magnesium lignosulfonate acts as a stabilizing agent and UV blocker while NaBH4 is applied as a reducing agent. The influence of the number of bilayers (4 and 12) and the initial concentration of AgNO3 solution (10 mM and 20 mM) on UV protection factor (UPF) and antimicrobial activity against Gram-negative bacteria Escherichia coli, Grampositive bacteria Staphylococcus aureus and yeast Candida albicans was studied. The presence of nanocoating on the surface of cotton fabric is confirmed by FTIR and XPS analyses. XPS and FESEM analyses reveal a successful synthesis of Ag NPs on the surface of cotton fibers with an average dimension of 35 nm. A four bilayer coating is sufficient to reach maximum 50+ UV protection. Maximum reduction of all investigated microorganisms is achieved with 12 bilayers and application of 20 mM AgNO3 solution

The Electrocrystallization of Metals. Investigation of Zinc

In electrodeposition of zinc depending on the condition of deposition, various effects of electrocrystallization can be observed. In acid solution of zinc sulfate the considerable surface diffusion overpotential appears at lower values of the total overpotential, indicating the surface diffusion of actions as the rate determining step. An interesting dependence of exchange current density on pH with a minimum at pH - 2 indicate the probable change in structure of the reacting particle. The mechanism of the reaction is evaluated. In alkaline zincate solutions no surface diffusion limitations can be detected. However, due to the rather low zincate ion concentration and high exchange current density zinc deposition proceeds practically always under the diffusion control. Morphology of zinc deposited depends considerably on the value of the electrode potential. This can be seen from the experiments in which the deposition morphology was observed with a scanning electron microscope. It was found possible to disrupt the deposition repeatedly for microscopic observation and than continue deposition. At low overpotentials (up to 50 mV) epitaxial layer type growth was observed with the linear increase of the microstep width with time. For this effect a theory is proposed which accounts also for the observed effects of substrate orientation. At larger overpotentials (50-100 mV) boulder type deposit was observed, most of which were not epitaxial with the substrate. They are suggested to be originated by nucleation. The boulder density per cm2 is first sharply increasing, and then slowly decreasing with time. A statistical calculation for this is given based on the model that large boulders consume the smaller ones. With further deposition a small fraction of the boulders develop into dendrites, their number being limited by the available total current

A conceptual design tool: a sketch and fuzzy logic based system

Abstract: A real-time sketch and fuzzy logic based prototype system for conceptual design has been developed. This system comprises four phases. In the ® rst one, the system accepts the input of online free-hand sketches, and segments them into meaningful parts by using fuzzy knowledge to detect corners and in¯ection points on the sketched curves. The fuzzy knowledge is applied to capture user' s drawing intention in terms of sketching position, direction, speed and acceleration. During the second phase, each segmented subpart (curve) can be classi® ed and identi® ed as one of the following two-dimensional primitives: straight lines, circles, circular arcs, ellipses, elliptical arcs or B-spline curves. Then, two-dimensional topology information (connectivity, unitary constraints and pairwise constraints) is extracted dynamically from the identi® ed two-dimensional primitives. From the extracted information, more accurate two-dimensional geometry can be built up by a two-dimensional geometric constraint solver. The two-dimensional topology and geometry information is then employed to further interpretation of a three-dimensional geometry. The system can not only accept sketched input but also users' interactive input of two-and three-dimensional primitives. This makes it friendly and easier to use, in comparison with`sketched input only' or interactive input only' systems. Finally, examples are given to illustrate the system

Photophysical characterizations of 2-(4-Biphenylyl)-5 phenyl-1,3,4- oxadiazole in restricted geometry

Langmuir and Langmuir-Blodgett (LB) films of nonamphiphilic 2-(4-Biphenylyl)-5 phenyl-1,3,4- oxadiazole (abbreviated as PBD) mixed with stearic acid (SA) as well as also with the inert polymer matrix poly(methyl methacrylate) (PMMA) have been studied. Surface pressure versus area per molecule (-A) isotherms studies suggest that PBD molecules very likely stand vertically on the air-water interface and this arrangement allows the PBD molecules to form stacks and remain sandwiched between SA/PMMA molecules. At lower surface pressure phase separation between PBD and matrix molecules occur resulting due to repulsive interaction. However at higher surface pressure PBD molecules form aggregates. The UV-Vis absorption and Steady state fluorescence spectroscopic studies of the mixed LB films of PBD reveal the nature of the aggregates. H-type aggregates predominates in the mixed LB films whereas I-type aggregates predominates in the PBD-PMMA spin coated films. The degree of deformation produced in the electronic levels are largely affected by the film thickness and the surface pressure of lifting.Comment: 15 pages, 6 figure

Charge calibration of CsI(Tl)/photodiode spectroscopy systems

A charge calibration method for spectroscopy systems that use inorganic scintillators, photodiodes, and charge-sensitive preamplifiers is presented. The shaped square wave (SSW) method accounts for ballistic deficit when long decay time constants are present. The SSW method is demonstrated for CsI(T1) and compared to other calibration methods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/30115/1/0000491.pd

Influence of synthesis conditions on morphological features of the SBA-15 containing only elongated and rounded/spherical grains

Mesoporous silica SBA-15 materials of high specific surface area (similar to 700 m(2) g(-1)) were synthesized by using block copolymer Pluronic P123 as template and tetraethoxysilane as silica source. The obtained materials were characterized by XRD, nitrogen adsorption desorption measurements, SEM, EDS and AFM analysis. It was found that small modifications of synthesis conditions influenced the morphological features of the synthesized SBA-15 samples. The SEM analysis had shown that the SBA-15 synthesized at lower temperature and longer time of reaction (80 degrees C, 48 h) provided elongated rod-shaped grains about 1 mu m long. The other sample synthesized at higher temperature and shorter time of reaction (100 degrees C, 24 h) had rounded grains and grains of regular spherical shape with diameters ranging from 0.5 to 2 mu m. The EDS analysis confirmed that the particles of both synthesized samples were of the SiO2 content. In addition, the AFM analysis had shown different surface morphologies of the materials synthesized under various conditions

Pulse-Shape discrimination with the Counting Test Facility

Pulse shape discrimination (PSD) is one of the most distinctive features of liquid scintillators. Since the introduction of the scintillation techniques in the field of particle detection, many studies have been carried out to characterize intrinsic properties of the most common liquid scintillator mixtures in this respect. Several application methods and algorithms able to achieve optimum discrimination performances have been developed. However, the vast majority of these studies have been performed on samples of small dimensions. The Counting Test Facility, prototype of the solar neutrino experiment Borexino, as a 4 ton spherical scintillation detector immersed in 1000 tons of shielding water, represents a unique opportunity to extend the small-sample PSD studies to a large-volume setup. Specifically, in this work we consider two different liquid scintillation mixtures employed in CTF, illustrating for both the PSD characterization results obtained either with the processing of the scintillation waveform through the optimum Gatti's method, or via a more conventional approach based on the charge content of the scintillation tail. The outcomes of this study, while interesting per se, are also of paramount importance in view of the expected Borexino detector performances, where PSD will be an essential tool in the framework of the background rejection strategy needed to achieve the required sensitivity to the solar neutrino signals.Comment: 39 pages, 17 figures, submitted to Nucl. Instr. Meth.