19,490 research outputs found
Quantization of spontaneously broken gauge theory based on the BFT-BFV Formalism
We quantize the spontaneously broken abelian U(1) Higgs model by using the
improved BFT and BFV formalisms. We have constructed the BFT physical fields,
and obtain the first class observables including the Hamiltonian in terms of
these fields. We have also explicitly shown that there are exact form
invariances between the second class and first class quantities. Then,
according to the BFV formalism, we have derived the corresponding Lagrangian
having U(1) gauge symmetry. We also discuss at the classical level how one
easily gets the first class Lagrangian from the symmetry-broken second class
Lagrangian.Comment: 16 pages, latex, final version published in Mod. Phys. Lett.
Comparison between the Use of LMAâ„¢ and SLIPAâ„¢ in Patients Undergoing Minor Surgeries.
Supraglottic airway devices have been used as safe alternatives to endotracheal intubation in appropriate types of surgery. This was a prospective, randomised, single blind study comparing the use of LMAâ„¢ and SLIPAâ„¢ in terms of ease of insertion, haemodynamic changes and occurrence of adverse effects (e.g. blood stains on the device upon removal and sore throat). A total of 62 ASA I or II patients, aged between 18 to 70 years were recruited for this study. Patients were randomised into two groups; LMAâ„¢ and SLIPAâ„¢ group. Following induction of anaesthesia, an appropriate sized LMAâ„¢ or SLIPAâ„¢ was inserted after ensuring adequate depth of anaesthesia. Anaesthesia was maintained with oxygen, nitrous oxide and sevoflurane. The ease of insertion was graded and haemodynamic changes were recorded at 2 minute intervals up to 10 minutes after insertion of the airway devices. The presence of blood stains upon airway device removal at the end of surgery and incidence of sore throat was also recorded. No difficult insertion was experienced in either of these devices. Insertion was either easy [LMAâ„¢ 87.1% versus SLIPAâ„¢ 80.6% (p = 0.49)] or moderate [LMAâ„¢ 12.9% versus SLIPAâ„¢ 19.4% (p = 0.16)]. Throughout the study period, the haemodynamic changes that occurred in both groups were not statistically different. Traces of blood were noted on the surface of the device in 9.7% of patients in the SLIPAâ„¢ group versus 6.5% of patients in the LMAâ„¢ group. The incidence of sore throat was recorded in 12.9% versus 19.4% of patients in the SLIPAâ„¢ and the LMAâ„¢ groups respectively. These findings were not statistically significant. In conclusion, this study showed no significant differences between the use of LMAâ„¢ and SLIPAâ„¢ in terms of ease of insertion, haemodynamic changes and adverse effects in patients undergoing minor surgical procedures
Wind Energy Forecasting: A Collaboration of the National Center for Atmospheric Research (NCAR) and Xcel Energy
The focus of this report is the wind forecasting system developed during this contract period with results of performance through the end of 2010. The report is intentionally high-level, with technical details disseminated at various conferences and academic papers. At the end of 2010, Xcel Energy managed the output of 3372 megawatts of installed wind energy. The wind plants span three operating companies1, serving customers in eight states2, and three market structures3. The great majority of the wind energy is contracted through power purchase agreements (PPAs). The remainder is utility owned, Qualifying Facilities (QF), distributed resources (i.e., 'behind the meter'), or merchant entities within Xcel Energy's Balancing Authority footprints. Regardless of the contractual or ownership arrangements, the output of the wind energy is balanced by Xcel Energy's generation resources that include fossil, nuclear, and hydro based facilities that are owned or contracted via PPAs. These facilities are committed and dispatched or bid into day-ahead and real-time markets by Xcel Energy's Commercial Operations department. Wind energy complicates the short and long-term planning goals of least-cost, reliable operations. Due to the uncertainty of wind energy production, inherent suboptimal commitment and dispatch associated with imperfect wind forecasts drives up costs. For example, a gas combined cycle unit may be turned on, or committed, in anticipation of low winds. The reality is winds stayed high, forcing this unit and others to run, or be dispatched, to sub-optimal loading positions. In addition, commitment decisions are frequently irreversible due to minimum up and down time constraints. That is, a dispatcher lives with inefficient decisions made in prior periods. In general, uncertainty contributes to conservative operations - committing more units and keeping them on longer than may have been necessary for purposes of maintaining reliability. The downside is costs are higher. In organized electricity markets, units that are committed for reliability reasons are paid their offer price even when prevailing market prices are lower. Often, these uplift charges are allocated to market participants that caused the inefficient dispatch in the first place. Thus, wind energy facilities are burdened with their share of costs proportional to their forecast errors. For Xcel Energy, wind energy uncertainty costs manifest depending on specific market structures. In the Public Service of Colorado (PSCo), inefficient commitment and dispatch caused by wind uncertainty increases fuel costs. Wind resources participating in the Midwest Independent System Operator (MISO) footprint make substantial payments in the real-time markets to true-up their day-ahead positions and are additionally burdened with deviation charges called a Revenue Sufficiency Guarantee (RSG) to cover out of market costs associated with operations. Southwest Public Service (SPS) wind plants cause both commitment inefficiencies and are charged Southwest Power Pool (SPP) imbalance payments due to wind uncertainty and variability. Wind energy forecasting helps mitigate these costs. Wind integration studies for the PSCo and Northern States Power (NSP) operating companies have projected increasing costs as more wind is installed on the system due to forecast error. It follows that reducing forecast error would reduce these costs. This is echoed by large scale studies in neighboring regions and states that have recommended adoption of state-of-the-art wind forecasting tools in day-ahead and real-time planning and operations. Further, Xcel Energy concluded reduction of the normalized mean absolute error by one percent would have reduced costs in 2008 by over $1 million annually in PSCo alone. The value of reducing forecast error prompted Xcel Energy to make substantial investments in wind energy forecasting research and development
A Particle Element Approach for Modelling the 3D Printing Process of Fibre Reinforced Polymer Composites
This paper presents a new numerical approach for modelling the 3D printing process of fibre reinforced polymer composites by fused deposition modelling (FDM). The approach is based on the coupling between two particle methods, namely smoothed particle hydrodynamics (SPH) and discrete element method (DEM). The coupled SPH-DEM model has distinctive advantages in dealing with the free surface flow, large deformation of fibres, and/or fibre-fibre interaction that are involved in the FDM process. A numerical feasibility study is carried out to demonstrate its capability for both short and continuous fibre reinforced polymer composites, with promising results achieved for the rheological flow and fibre orientation and deformation. View Full-Tex
Tripartite thermal correlations in an inhomogeneous spin-star system
We exploit the tripartite negativity to study the thermal correlations in a
tripartite system, that is the three outer spins interacting with the central
one in a spin-star system. We analyze the dependence of such correlations on
the homogeneity of the interactions, starting from the case where central-outer
spin interactions are identical and then focusing on the case where the three
coupling constants are different. We single out some important differences
between the negativity and the concurrence.Comment: 8 pages, 9 figure
Observation-driven adaptive differential evolution and its application to accurate and smooth bronchoscope three-dimensional motion tracking
© 2015 Elsevier B.V. This paper proposes an observation-driven adaptive differential evolution algorithm that fuses bronchoscopic video sequences, electromagnetic sensor measurements, and computed tomography images for accurate and smooth bronchoscope three-dimensional motion tracking. Currently an electromagnetic tracker with a position sensor fixed at the bronchoscope tip is commonly used to estimate bronchoscope movements. The large tracking error from directly using sensor measurements, which may be deteriorated heavily by patient respiratory motion and the magnetic field distortion of the tracker, limits clinical applications. How to effectively use sensor measurements for precise and stable bronchoscope electromagnetic tracking remains challenging. We here exploit an observation-driven adaptive differential evolution framework to address such a challenge and boost the tracking accuracy and smoothness. In our framework, two advantageous points are distinguished from other adaptive differential evolution methods: (1) the current observation including sensor measurements and bronchoscopic video images is used in the mutation equation and the fitness computation, respectively and (2) the mutation factor and the crossover rate are determined adaptively on the basis of the current image observation. The experimental results demonstrate that our framework provides much more accurate and smooth bronchoscope tracking than the state-of-the-art methods. Our approach reduces the tracking error from 3.96 to 2.89. mm, improves the tracking smoothness from 4.08 to 1.62. mm, and increases the visual quality from 0.707 to 0.741
Transcriptome and metabolome reveal redirection of flavonoids in a white testa peanut mutant
Background: Coat color determines both appearance and nutrient quality of peanut. White seed coat in peanut
can enhance the processing efficiency and quality of peanut oil. An integrative analysis of transcriptomes,
metabolomes and histocytology was performed on wsc mutant and its wild type to investigate the regulatory
mechanisms underlying color pigmentation.
Result: Metabolomes revealed flavonoids were redirected in wsc, while multi-omics analyses of wsc mutant seeds
and testae uncovered WSC influenced the flavonoids biosynthesis in testa as well as suberin formation, glycolysis,
the TCA cycle and amino acid metabolism. The mutation also enhanced plant hormones synthesis and signaling.
Further, co-expression analysis showed that FLS genes co-expressed with MBW complex member genes.
Combining tissue expression patterns, genetic analyses, and the annotation of common DEGs for these three stages
revealed that three testa specific expressed candidate genes, Araip.M7RY3, Aradu.R8PMF and Araip.MHR6K were likely
responsible for the white testa phenotype. WSC might be regulated expression competition between FLS and DFR
by controlling hormone synthesis and signaling as well as the MBW complex.
Conclusions: The results of this study therefore provide both candidate genes and novel approaches that can be
applied to improve peanut with desirable seed coat color and flavonoid quality
Faktor-faktor yang Mempengaruhi Citra Tubuh Pasien Diabetes Melitus yang Mengalami Ulkus Diabetikum
The purpose of this research is to identify influencing factor of body image among diabetic patient by foot ulcer at Arifin Achmad hospitals Riau province. The research used correlative descriptive with cross sectional approach as its design. The number of samples is 30 people taken using pusposive sampling technique. The analysis used was univariate using frequency distribution and bivariate analysis using chi-square test. Based on the statistical test (chi-square) results, it is concluded that there is significant between changes in body apprearance with body image [p value <α (0,042<0,05)], there is significant between changes in function of body with body image [p value <α (0,011<0,05)], there is significant between reactions of others with body image [p value <α (0,027<0,05)] and there is significant between comparison of others with body image [p value <α (0,033<0,05)]. The result of research expected nurse more pay attention to psychological aspects when giving nursing interventio
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