Optimal Net-Load Balancing in Smart Grids with High PV Penetration

Mitigating Supply-Demand mismatch is critical for smooth power grid operation. Traditionally, load curtailment techniques such as Demand Response (DR) have been used for this purpose. However, these cannot be the only component of a net-load balancing framework for Smart Grids with high PV penetration. These grids can sometimes exhibit supply surplus causing over-voltages. Supply curtailment techniques such as Volt-Var Optimizations are complex and computationally expensive. This increases the complexity of net-load balancing systems used by the grid operator and limits their scalability. Recently new technologies have been developed that enable the rapid and selective connection of PV modules of an installation to the grid. Taking advantage of these advancements, we develop a unified optimal net-load balancing framework which performs both load and solar curtailment. We show that when the available curtailment values are discrete, this problem is NP-hard and develop bounded approximation algorithms for minimizing the curtailment cost. Our algorithms produce fast solutions, given the tight timing constraints required for grid operation. We also incorporate the notion of fairness to ensure that curtailment is evenly distributed among all the nodes. Finally, we develop an online algorithm which performs net-load balancing using only data available for the current interval. Using both theoretical analysis and practical evaluations, we show that our net-load balancing algorithms provide solutions which are close to optimal in a small amount of time.Comment: 11 pages. To be published in the 4th ACM International Conference on Systems for Energy-Efficient Built Environments (BuildSys 17) Changes from previous version: Fixed a bug in Algorithm 1 which was causing some min cost solutions to be misse

Isospin effects on the mass dependence of balance energy

We study the effect of isospin degree of freedom on balance energy throughout the mass range between 50 and 350 for two sets of isotopic systems with N/Z = 1.16 and 1.33 as well as isobaric systems with N/Z = 1.0 and 1.4. Our findings indicate that different values of balance energy for two isobaric systems may be mainly due to the Coulomb repulsion. We also demonstrate clearly the dominance of Coulomb repulsion over symmetry energy.Comment: 5 pages, 3 figures In this version the discussion is in terms of N/Z whereas in the journal the whole discussion is in terms of N/A. The conclusions remain unaffecte

Pirolisis Biomassa Pelepah Sawit Menjadi Bio - Oil dengan Katalis Natural Zeolit Dealuminated (NZA)

Petroleum as a primary energy source at this time, increasingly limited supply. Beside the population growth will lead to the increasing need for petroleum. To overcome these problems needed alternative energy sources that can be updated is one of the bio-oil. Bio-oil produced by pyrolysis process using biomass with warming, in the absence of oxygen. The purpose of this study was to determine the effect of variations in the catalyst on the yield of bio-oil produced, knowing the value of density, viscosity, acid number and flash point of bio-oil as well as knowing the chemical components of the bio-oil by GC-MS method. Pyrolysis uses palm frond as much as 50 grams along with 500 ml silinap with NZA catalysts variation of 0%, 1%, 2%, 3%, and 4% w / w with a stirring speed of 300 rpm and a temperature of 320 º C for 120 minutes. In this penelitiam largest yield obtained on the catalyst NZA 3% variation of 44.4%. Characteristics of physical properties obtained are: density of 0.996 g / ml, 11.733 cSt viscosity, acid number 79.34 g NaOH / g sample, as well as the flash point 58 º C. The results of GC-MS analysis, the dominant chemical components in bio-oil are acetic acid (40.90%); methanol (9.60%); methyl ester (2.30%); phenol (32.88%); 2-furancarboxaldehyde (8.98%)

Pantheism and Escapism in Abu Madi\u27s \u27Enigmas\u27 and \u27The Evening\u27 From English Romanticism Perspectives

In his article Pantheism and Escapism in Abu Madi\u27s \u27Enigmas\u27 and \u27The Evening\u27 From English Romanticism Perspectives Yasser K. R. Aman investigates and analyses the possibilities of pantheism\u27s encirclement of escapism in Elia Abu Madi\u27s two poems from English Romanticism perspective. The article compares Abu Madi\u27s fluctuating attitude towards escapism and pantheism to William Wordsworth\u27s Lines Composed a Few Miles above Tintern Abbey, On Revisiting the Banks of the Wye during a Tour July 13, 1798, Samuel Taylor Coleridge\u27s The Rime of the Ancient Mariner, and Percy Bysshe Shelley\u27s Ode to the West Wind, highlighting the affinities and differences. The argument of the article is that Abu Madi\u27s skepticism in Engimas (الطلاسم), a representative poem of his works and of contemporary Arab romanticism, hinders him from finding an escape from the here and the now; while in The Evening (المساء), which displays overflow of feelings, Abu Madi makes his escape from the burdens of life and mingles with nature. Therefore, Abu Madi represents the fluctuation of contemporary Arab romantic poets, especially Al Mahjar School: either to embrace pantheism or to retreat in an impenetrable shell of self-isolation

Nuclear Dynamics at the Balance Energy

We study the mass dependence of various quantities (like the average and maximum density, collision rate, participant-spectator matter, temperature as well as time zones for higher density) by simulating the reactions at the energy of vanishing flow. This study is carried out within the framework of Quantum Molecular Dynamics model. Our findings clearly indicate an existence of a power law in all the above quantities calculated at the balance energy. The only significant mass dependence was obtained for the temperature reached in the central sphere. All other quantities are rather either insensitive or depend weakly on the system size at balance energy. The time zone for higher density as well as the time of maximal density and collision rate follow a power law inverse to the energy of vanishing flow.Comment: 9 figures, Submitted to Phys. Rev.

Geometrothermodynamics of black holes

The thermodynamics of black holes is reformulated within the context of the recently developed formalism of geometrothermodynamics. This reformulation is shown to be invariant with respect to Legendre transformations, and to allow several equivalent representations. Legendre invariance allows us to explain a series of contradictory results known in the literature from the use of Weinhold's and Ruppeiner's thermodynamic metrics for black holes. For the Reissner-Nordstr\"om black hole the geometry of the space of equilibrium states is curved, showing a non trivial thermodynamic interaction, and the curvature contains information about critical points and phase transitions. On the contrary, for the Kerr black hole the geometry is flat and does not explain its phase transition structure.Comment: Revised version, to be published in Gen.Rel.Grav.(Mashhoon's Festschrift

The Role of Irradiation in Hypophyseal Adenoma

Pituitary adenomas are histopathologically benign, however the clinical presentations are often quite severe. These clinical signs are due to the tumor mass effect, hormonal disturbances or both. Besides that, these tumors often recurred after treatment. The treatment of pituitary tumors have developed greatly with the improvement of techniques of several modalities such as surgery, radiation and medication. Multimodality treatment is often used for optimal results in treating these tumors. Radiotherapy is a cytotoxic agent using ion radiation for the treatment of pituitary tumors in combination with other methods. Post-surgical radiotherapy has shown to decrease the recurrence rate significantly (22-71% vs 8-23%). At present there has been rapid improvements in radiation techniques for pituitary tumors. These developments are not only based upon the increase of know-how in computer technology and radiation instruments, but are also based upon the development of cellular and molecular biology in connection with normal and tumor tissues. The objective in developing radiation methods and techniques is to create a high radiation dose, homogeneous in the target area with low radiation dose in normal tissue. The development in science and technology, in particular concerning computer science, have created the development of radiation techniques and methods. This paper elaborates on several aspects of radiation in the treatment of pituitary