525 resultados para Smart truss structure


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In this chapter, the role of State Estimation (SE) in smart power grids is presented. The trend of SE error with respect to the increasing of the smart grids implementation investigated. The observability analysis as a prior task of SE is demonstrated and an analytical method to consider the impedance values of the branches is developed and discussed by examples. Since most principles of smart power grids are appropriate to distribution networks, the Distribution SE (DSE)considering load correlation is argued and illustrated by an example. The main features of smart grid SE, which is here named as “Smart Distributed SE” (SDSE), are discussed. Some characteristics of proposed SDES are distributed, hybrid, multi-micro grid and islanding support, Harmonic State Estimation (HSE), observability analysis and restore, error processing, and network parameter estimation. Distribution HSE (DHSE) and meter placement for SDSE are also presented.

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Density functional calculations of the electronic band structure for superconducting and semi-conducting metal hexaborides are compared using a consistent suite of assumptions and with emphasis on the physical implications of computed models. Spin polarization enhances mathematical accuracy of the functional approximations and adds significant physical meaning to model interpretation. For YB6 and LaB6, differences in alpha and beta projections occur near the Fermi energy. These differences are pronounced for superconducting hexaborides but do not occur for other metal hexaborides.

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Aims Pathology notification for a Cancer Registry is regarded as the most valid information for the confirmation of a diagnosis of cancer. In view of the importance of pathology data, an automatic medical text analysis system (Medtex) is being developed to perform electronic Cancer Registry data extraction and coding of important clinical information embedded within pathology reports. Methods The system automatically scans HL7 messages received from a Queensland pathology information system and analyses the reports for terms and concepts relevant to a cancer notification. A multitude of data items for cancer notification such as primary site, histological type, stage, and other synoptic data are classified by the system. The underlying extraction and classification technology is based on SNOMED CT1 2. The Queensland Cancer Registry business rules3 and International Classification of Diseases – Oncology – Version 34 have been incorporated. Results The cancer notification services show that the classification of notifiable reports can be achieved with sensitivities of 98% and specificities of 96%5, while the coding of cancer notification items such as basis of diagnosis, histological type and grade, primary site and laterality can be extracted with an overall accuracy of 80%6. In the case of lung cancer staging, the automated stages produced were accurate enough for the purposes of population level research and indicative staging prior to multi-disciplinary team meetings2 7. Medtex also allows for detailed tumour stream synoptic reporting8. Conclusions Medtex demonstrates how medical free-text processing could enable the automation of some Cancer Registry processes. Over 70% of Cancer Registry coding resources are devoted to information acquisition. The development of a clinical decision support system to unlock information from medical free-text could significantly reduce costs arising from duplicated processes and enable improved decision support, enhancing efficiency and timeliness of cancer information for Cancer Registries.

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We have studied a mineral sample of mottramite PbCu(VO4)(OH) from Tsumeb, Namibia using a combination of scanning electron microscopy with EDX, Raman and infrared spectroscopy. Chemical analysis shows principally the elements V, Pb and Cu. Ca occurs as partial substitution of Pb as well as P and As in substitution to V. Minor amounts of Si and Cr were also observed. The Raman band of mottramite at 829 cm-1, is assigned to the ν1 symmetric (VO-4) ) stretching mode. The complexity of the spectra is attributed to the chemical composition of the Tsumeb mottramite. The ν3 antisymmetric vibrational mode of mottramite is observed as very low intensity bands at 716 and 747 cm-1. The series of Raman bands at 411, 439, 451 cm-1 and probably also the band at 500 cm-1 are assigned to the (VO-4) ν2 bending mode. The series of Raman bands at 293, 333 and 366 cm-1 are attributed to the (VO-4) ) ν4 bending modes. The ν3, ν3 and ν4 regions are complex for both minerals and this is attributed to symmetry reduction of the vanadate unit from Td to Cs.

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We have studied the borate mineral rhodizite (K, Cs)Al4Be4(B, Be)12O28 using a combination of DEM with EDX and vibrational spectroscopic techniques. The mineral occurs as colorless, gray, yellow to white crystals in the triclinic crystal system. The studied sample is from the Antandrokomby Mine, Sahatany valley, Madagascar. The mineral is prized as a semi-precious jewel. Semi-quantitative chemical composition shows a Al, Ca, borate with minor amounts of K, Mg and Cs. The mineral has a characteristic borate Raman spectrum and bands are assigned to the stretching and bending modes of B, Be and Al. No Raman bands in the OH stretching region were observed.

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The mineral beraunite from Boca Rica pegmatite in Minas Gerais with theoretical formula Fe2+Fe5 3+(PO4)4(OH)5⋅4H2O has been studied using a combination of electron microscopy with EDX and vibrational spectroscopic techniques. Raman spectroscopy identifies an intense band at 990 cm-1 and 1011 cm-1. These bands are attributed to the PO4 3- v, symmetric stretching mode. The m3 antisymmetric stretching modes are observed by a large number of Raman bands. The Raman bands at 1034, 1051, 1058, 1069 and 1084 together with the Raman bands at 1098, 1116, 1133, 1155 and 1174 cm-1 are assigned to the m3 antisymmetric stretching vibrations of PO4 3- and the HOPO3 2- units. The observation of these multiple Raman bands in the symmetric and antisymmetric stretching region gives credence to the concept that both phosphate and hydrogen phosphate units exist in the structure of beraunite. The series of Raman bands at 567, 582,601, 644, 661, 673, and 687 cm-1 are assigned to the PO4 3- v2 bending modes. The series of Raman bands at 437, 468, 478, 491, 503 cm-1 are attributed to the PO4 3- and OPO3 2- v4 bending modes. No Raman bands of beraunite which could be attributed to the hydroxyl stretching unit were observed. Infrared bands at 3511 and 3359 cm-1 are ascribed to the OH stretching vibration of the OH units. Very broad bands at 3022 and 3299 cm-1 are attributed to the OH stretching vibrations of water. Vibrational spectroscopy offers insights into the molecular structure of the phosphate mineral beraunite.

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The structure of several carboxy-substituted hexahydro-1,4:5,8-diepoxynaphthalenes have been solved with X-ray crystallography, in some cases confirming previously contentious structures. The compounds of interest are constructed in efficient one-step 2 × [4+2] cycloaddition reactions from furan and acetylene carboxylate derivatives.

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The ion (C2CHC2)(-) is formed in the gas phase by the process -C=C-CH(OCOR)-C=CD --> (C2CHC2)(-) + ('RDCO2') [R = H, Me or Et]; the ground state structure is a singlet, with C-2 nu symmetry.

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The mineral leightonite, a rare sulphate mineral of formula K2Ca2Cu(SO4)4.2H2O, has been studied using a combination of electron probe and vibrational spectroscopy. The mineral is characterized by an intense Raman band at 991 cm-1 attributed to the SO2- 4 m1 symmetric stretching mode. A series of Raman bands at 1047, 1120, 1137, 1163 and 1177 cm-1 assigned to the SO2- 4 m3 antisymmetric stretching modes. The observation of multiple bands shows that the symmetry of the sulphate anion is reduced. Multiple Raman and infrared bands in the OH stretching region shows that water in the structure of leightonite is in a range of molecular environments.

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The characterization of X-ray diffraction, X-ray fluorescence, and field emission scanning electron microscope were used to confirm the successful preparation of Al-substituted goethite with different Al content. The micro-Raman spectroscopy was utilized to investigate the effect of Al content on the goethite lattice. The results show that all the feature bands of goethite shifted to high wavenumbers after the occurrence of Al substitution for Fe in the structure of goethite. The shift of wavenumber shows a good linear relationship as a function of increasing Al content especially for the band at 299 cm−1 (R2 = 0.9992). The in situ Raman spectroscopy of thermally treated goethite indicated that the Al substitution not only hinders the transformation of goethite, but also retarded the crystallization of thermally formed hematite. All the results indicated that Raman spectrum displayed an excellent performance in characterizing Al-substituted goethite, which implied the promising application in other substituted metal oxides or hydroxides.

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In this paper, we introduce a vision called Smart Material Interfaces (SMIs), which takes advantage of the latest generation of engineered materials that has a special property defined “smart”. They are capable of changing their physical properties, such as shape, size and color, and can be controlled by using certain stimuli (light, potential difference, temperature and so on). We describe SMIs in relation to Tangible User Interfaces (TUIs) to convey the usefulness and a better understanding of SMIs.

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Increasing the importance and use of infrastructures such as bridges, demands more effective structural health monitoring (SHM) systems. SHM has well addressed the damage detection issues through several methods such as modal strain energy (MSE). Many of the available MSE methods either have been validated for limited type of structures such as beams or their performance is not satisfactory. Therefore, it requires a further improvement and validation of them for different types of structures. In this study, an MSE method was mathematically improved to precisely quantify the structural damage at an early stage of formation. Initially, the MSE equation was accurately formulated considering the damaged stiffness and then it was used for derivation of a more accurate sensitivity matrix. Verification of the improved method was done through two plane structures: a steel truss bridge and a concrete frame bridge models that demonstrate the framework of a short- and medium-span of bridge samples. Two damage scenarios including single- and multiple-damage were considered to occur in each structure. Then, for each structure, both intact and damaged, modal analysis was performed using STRAND7. Effects of up to 5 per cent noise were also comprised. The simulated mode shapes and natural frequencies derived were then imported to a MATLAB code. The results indicate that the improved method converges fast and performs well in agreement with numerical assumptions with few computational cycles. In presence of some noise level, it performs quite well too. The findings of this study can be numerically extended to 2D infrastructures particularly short- and medium-span bridges to detect the damage and quantify it more accurately. The method is capable of providing a proper SHM that facilitates timely maintenance of bridges to minimise the possible loss of lives and properties.

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Titanium oxide films with trilayer structure grown on fluorine doped tin oxide substrate were prepared from one-step hydrothermal process. The trilayer structure consists of microflowers, nanorod array and compact nanoparticulates, which is expected to possess the merits of good light harvesting, a high electron transport rate, while avoiding the issues of electron shunting. The photovoltaic performance was comprehensively studied and a 60% enhancement in short circuit photocurrent density was found from microflowers contribution as a light scattering layer. This unique trilayer structure exhibits great potential application in future dye-sensitized solar cells.

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A pulsed wall jet has been used to simulate the gust front of a thunderstorm downburst. Flow visualization, wind speed and surface pressure measurements were obtained. The characteristics of the hypothesized ring vortex of a full-scale downburst were reproduced at a scale estimated to be 1:3000.

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Doping is an effective approach that allows for the intrinsic modification of the electrical and chemical properties of nanomaterials. Recently, a graphene and carbon nanotube hybrid structure (GNHS) has been reported, which extends the excellent properties of carbon-based materials to three dimensions. In this paper, we carried out a first-time investigation on the tensile properties of the hybrid structures with different dopants. It is found that with the presence of dopants, the hybrid structures usually exhibit lower yield strength, Young’s modulus, and earlier yielding compared to that of a pristine hybrid structure. For dopant concentrations below 2.5% no significant reduction of Young’s modulus or yield strength could be observed. For all considered samples, the failure is found to initiate at the region where the nanotubes and graphene sheets are connected. After failure, monatomic chains are normally observed around the failure region. Dangling graphene layers without the separation of a residual CNT wall are found to adhere to each other after failure with a distance of about 3.4 Å. This study provides a fundamental understanding of the tensile properties of the doped graphene–nanotube hybrid structures, which will benefit the design and also the applications of graphene-based hybrid materials.