Life cycle assessment and feasibility study of small wind power in Thailand

The Thai government’s implementation of its 10 year renewable energy plan was done to help increase energy independence and reduce emissions resulting from energy production. Due to Thailand’s wind regime, wind turbines which can operate in low wind speeds will be needed to meet this goal. Small wind turbines typically operate at higher efficiency in lower winds, and thus they might prove to be a good option for wind power production in Thailand. Incorporating small wind turbines into power production can be difficult because of the perception of high investment costs and because their net benefit has not been adequately studied. Using a functional unit of producing 50 kWh per month for 10 years we conducted a Life Cycle Assessment comparing the global warming potential (GWP), embodied energy (EE), and levelized cost of electricity (LCOE) of four small wind turbines (≤20 kW), a diesel generator, and the Thai Grid. When analyzing GWP of the turbines it was found that they had a lower overall GWP than the diesel generator when in areas with reasonable wind resources. The same is true for embodied energy. Interestingly, in most available wind speed categories in Thailand the LCOE for wind turbines was lower than for the diesel generator. However, neither could compare to the LCOE of the Thai Grid, except in the areas with the highest average wind speeds (7.0 -­‐9.4 m/s). With this in mind, it is clear that the most important factor when considering wind power generation is the wind regime available in an area. Because of the increased cost relative to the Thai grid, implementation of wind turbines in Thailand was not found to be economically viable. This could be changed given lower costs for turbines and/or government incentives

Workshop on Engineering Turbulence Modeling

Discussed here is the future direction of various levels of engineering turbulence modeling related to computational fluid dynamics (CFD) computations for propulsion. For each level of computation, there are a few turbulence models which represent the state-of-the-art for that level. However, it is important to know their capabilities as well as their deficiencies in order to help engineers select and implement the appropriate models in their real world engineering calculations. This will also help turbulence modelers perceive the future directions for improving turbulence models. The focus is on one-point closure models (i.e., from algebraic models to higher order moment closure schemes and partial differential equation methods) which can be applied to CFD computations. However, other schemes helpful in developing one-point closure models, are also discussed

A New K-epsilon Eddy Viscosity Model for High Reynolds Number Turbulent Flows: Model Development and Validation

A new k-epsilon eddy viscosity model, which consists of a new model dissipation rate equation and a new realizable eddy viscosity formulation, is proposed. The new model dissipation rate equation is based on the dynamic equation of the mean-square vorticity fluctuation at large turbulent Reynolds number. The new eddy viscosity formulation is based on the realizability constraints: the positivity of normal Reynolds stresses and Schwarz' inequality for turbulent shear stresses. We find that the present model with a set of unified model coefficients can perform well for a variety of flows. The flows that are examined include: (1) rotating homogeneous shear flows; (2) boundary-free shear flows including a mixing layer, planar and round jets; (3) a channel flow, and flat plate boundary layers with and without a pressure gradient; and (4) backward facing step separated flows. The model predictions are compared with available experimental data. The results from the standard k-epsilon eddy viscosity model are also included for comparison. It is shown that the present model is a significant improvement over the standard k-epsilon eddy viscosity model

Visualization of the operational space of edge-localized modes through low-dimensional embedding of probability distributions

Information visualization aimed at facilitating human perception is an important tool for the interpretation of experiments on the basis of complex multidimensional data characterizing the operational space of fusion devices. This work describes a method for visualizing the operational space on a two-dimensional map and applies it to the discrimination of type I and type III edge-localized modes (ELMs) from a series of carbon-wall ELMy discharges at JET. The approach accounts for stochastic uncertainties that play an important role in fusion data sets, by modeling measurements with probability distributions in a metric space. The method is aimed at contributing to physical understanding of ELMs as well as their control. Furthermore, it is a general method that can be applied to the modeling of various other plasma phenomena as well

Brain Tumor and Glioma Grade Classification Using Gaussian Convolutional Neural Network

Understanding brain diseases such as categorizing Brain-Tumor (BT) is critical to assess the tumors and facilitate the patient with proper cure as per their categorizations. Numerous imaging schemes exist for BT detection, such as Magnetic Resonance Imaging (MRI), generally utilized because of the better quality of images and the reality of depending on non-ionizing radiation. This paper proposes an approach to detect distinctive BT types using Gaussian Convolutional Neural Network (GCNN) on two datasets. One of the datasets is used to classify tumors into pituitary, glioma, and meningioma. The other one separates the three grades of glioma, i.e., Grade-two, Grade-three, and Grade-four. These datasets have '233' and '73' victims with a total of '3064' and '516' images on T1-weighted complexity improved pictures for the first and second datasets, separately. The proposed approach achieves an accuracy of 99.8% and 97.14% for the two datasets. The experimental results highlight the efficiency of the proposed approach for BT multi-class categorization

Natural mutations of human XDH promote the nitrite (NO2 −)-reductase capacity of xanthine oxidoreductase: A novel mechanism to promote redox health?

Several rare genetic variations of human XDH have been shown to alter xanthine oxidoreductase (XOR) activity leading to impaired purine catabolism. However, XOR is a multi-functional enzyme that depending upon the environmental conditions also expresses oxidase activity leading to both O2·- and H2O2 and nitrite (NO2−) reductase activity leading to nitric oxide (·NO). Since these products express important, and often diametrically opposite, biological activity, consideration of the impact of XOR mutations in the context of each aspect of the biochemical activity of the enzyme is needed to determine the potential full impact of these variants. Herein, we show that known naturally occurring hXDH mutations do not have a uniform impact upon the biochemical activity of the enzyme in terms of uric acid (UA), reactive oxygen species (ROS) and nitric oxide ·NO formation. We show that the His1221Arg mutant, in the presence of xanthine, increases UA, O2·- and NO generation compared to the WT, whilst the Ile703Val increases UA and ·NO formation, but not O2·-. We speculate that this change in the balance of activity of the enzyme is likely to endow those carrying these mutations with a harmful or protective influence over health that may explain the current equipoise underlying the perceived importance of XDH mutations. We also show that, in presence of inorganic NO2−, XOR-driven O2·- production is substantially reduced. We suggest that targeting enzyme activity to enhance the NO2−-reductase profile in those carrying such mutations may provide novel therapeutic options, particularly in cardiovascular disease

A Compact Single Layer Reflectarray Antenna Based on Circular Delay-Lines for X-band Applications

This paper presents a compact single layer reflectarray antenna based on a diagonally notched square patch and a pair of circular delay lines, for X-band applications. The length and width of circular delay-lines are varied and optimized to attain a linear phase range of more than 600º. The effect of incident angle in TE and TM modes at 0º, 15º and 30º is studied, which offers stable angular phase range. The hybrid Finite Element Boundary Integral (FEBI) method is used for simulation of the whole reflectarray system comprising of 27 × 27 elements and being fabricated on a low cost FR-4 laminate. The measured gain of 24.5 dBi with aperture efficiency of 49.5% is achieved at 10 GHz. The proposed design provides the measured 1-dB gain bandwidth of 12.5% and 3-dB gain bandwidth of 34%. The simulated and measured side-lobe-levels and cross polarizations are less than –25 dB and –40 dB respectively

Synthesis, thermal, structural analyses and photoluminescent properties of a new family of malonate-containing lanthanide(III) coordination polymers

Five new Lanthanide(III) complexes of malonic acid (HOOC-CH2-COOH); {[Gd(C3H2O4)(H2O)4]•NO3}n (1), {[Tb(C3H2O4)(H2O)4]•NO3}n (2),{[Ho(C3H2O4)(H2O)4]•NO3}n (3), [Er(C3H2O4)(C3H3O4)(H2O)2]n (4) and {[Eu2(C3H2O4)2(C3H3O4)2(H2O)6]•4H2O}n (5) are synthesized and characterized by elemental, infrared spectral and thermal analyses. The structures of compounds 1-5 are determined by single crystal X-ray diffraction technique. The X-ray analysis reveals that compounds 1, 2 and 3 are isostructural and crystallized in the orthorhombic space group Pmn21. The lanthanide(III) ions are coordinated by four carboxylate and four water oxygen atoms adopting a distorted square antiprism geometry. The LnO8 square antiprisms are linked into infinite layers by malonate (C3H2O42–) dianions sandwiching sheets of nitrate counter ions. Compound 4 contains ErO8 square antiprisms linked into a two-dimensional network by hydrogen malonate (C3H3O4–) anions and malonate dianions. The europium complex, 5 is dinuclear having the two europium(III) ions (Eu1 and Eu2) bridged by carboxylate groups of hydrogen malonate ligands. The europium ions in 5 are nine-coordinate and exhibit a distorted monocapped square antiprism geometry. All the structures are consolidated by O–H∙∙∙O hydrogen bonds. The photoluminescence spectra of 1-5 exhibit characteristics emission in the visible region. The IR spectra and thermal data are consistent with the structural results. The room-temperature effective magnetic moments for 1–4 are in good agreement with those expected for the free ions, while the data for 5 indicates that low-lying excited states contribute to the observed moment. The compound 1 was further subjected to quantum computational calculations to explore its optoelectronic properties including; density of states (DOS), dielectric function, refractive index, extinction coefficient and absorption spectrum, to highlight the possible applications of such materials in the optoelectronics