An Example of Utilizing Stochastic Approach for Investigating Network Constraints (Congestions) on Horizontally Operated Power Systems with Distributed Generation

This paper shows an example of a stochastic approach to study the impact of distributed generation (DG) on the network constraints (congestions) in power systems. We assume the DG units to be customer-owned, so that they can be connected to or disconnected from the power system by their owners at random. Therefore, the DG units generate power in a stochastic way. The load in the system shows a random behavior too, and the probability distribution of the aggregated generated power and load demand of the distribution system are calculated using Monte Carlo Simulation (MCS).The network constraints (congestions) are evaluated based on the probability distributions of the power flows that result from the simulations. The method that is applied in this paper, shows that looking at the network constraints with a stochastic approach gives a more complete picture of the network than applying a deterministic method, especially when non-dispatchable DG units play a dominant role

Functional activation of the p53 tumor suppressor in non-tumorigenic variants of the HeLa cervical carcinoma cell line

Thesis (Sc. D.)--Massachusetts Institute of Technology, Division of Toxicology, 1996.Includes bibliographical references (leaves 119-131).by Maria G. Athanassiou-papaefthymiou.Sc.D

Iron Compounds in Brazilian Pre-Columbian Pigments Identified by \u3csup\u3e57\u3c/sup\u3eFe Mossbauer Spectroscopy and X-Ray Powder Diffraction

Mossbauer spectroscopy and X-ray powder diffraction have been used to identify iron compounds in pre-Columbian pigments, probably used for art decorating, collected from the oldest archaeological site of Early Man presently known in American at Sao Raimundo Nonato, in Northeastern Brazil. The iron compounds were identified as being alpha-Fe203 (haematite) with full Morin transition supressed and small particles of alpha-FeOOH (goethite)

Observation of Substitutional Site Preference in a Quasicrystal and Implication on Local Structure

A combination of magnetic susceptibility and Mössbauer measurements on quasicrystalline i-Al74Mn20-xFexSi6 (0.02≤x≤7.5) establishes that Mn atoms in i-Al74Mn20Si6 occupy two distinct classes of sites, and that Fe substitutes for only one of them. The two classes are distinguished by the possession or otherwise of a localized magnetic moment. The data are consistent with a structure of interconnecting Mackay icosahedra (MI) in which localized moments are possessed only by Mn atoms adjacent to broken MI connections. The implied connectivity of the resulting MI network is close to that anticipated for a packing of MI on a three-dimensional Penrose-tile lattice

Status and perspectives of hospital mortality in a public urban Hellenic hospital, based on a five-year review

<p>Abstract</p> <p>Background</p> <p>Analysis of hospital mortality helps to assess the standards of health-care delivery.</p> <p>Methods</p> <p>This is a retrospective cohort study evaluating the causes of deaths which occurred during the years 1995–1999 in a single hospital. The causes of death were classified according to the International Statistical Classification of Diseases (ICD-10).</p> <p>Results</p> <p>Of the 149,896 patients who were discharged the 5836 (3.4%) died. Males constituted 55% and females 45%. The median age was 75.1 years (1 day – 100 years).</p> <p>The seven most common ICD-10 chapters IX, II, IV, XI, XX, X, XIV included 92% of the total 5836 deaths.</p> <p>The most common contributors of non-neoplasmatic causes of death were cerebrovascular diseases (I60–I69) at 15.8%, ischemic heart disease (I20–I25) at 10.3%, cardiac failure (I50.0–I50.9) at 7.9%, diseases of the digestive system (K00–K93) at 6.7%, diabetes mellitus (E10–E14) at 6.6%, external causes of morbidity and mortality (V01–Y98) at 6.2%, renal failure (N17–N19) at 4.5%, influenza and pneumonia (J10–J18) at 4.1% and certain infectious and parasitic diseases (A00–B99) at 3.2%, accounting for 65.3% of the total 5836 deaths.</p> <p>Neoplasms (C00–D48) caused 17.7% (n = 1027) of the total 5836 deaths, with leading forms being the malignant neoplasms of bronchus and lung (C34) at 3.5% and the malignant neoplasms of large intestine (C18–21.2) at 1.5%. The highest death rates occurred in the intensive care unit (23.3%), general medicine (10.7%), cardiology (6.5%) and nephrology (5.5%).</p> <p>Key problems related to certification of death were identified. Nearly half of the deaths (49.3%: n = 2879) occurred by the completion of the third day, which indicates the time limits for investigation and treatment. On the other hand, 6% (n = 356) died between the 29^thand 262^nddays after admission.</p> <p>Inadequacies of the emergency care service, infection control, medical oncology, rehabilitation, chronic and terminal care facilities, as well as lack of regional targets for reducing mortality related to diabetes, recruitment of organ donors, provision for the aging population and lack of prevention programs were substantiated.</p> <p>Conclusion</p> <p>Several important issues were raised. Disease specific characteristics, as well as functional and infrastructural inadequacies were identified and provided evidence for defining priorities and strategies for improving the standards of care. Effective transformation can promise better prospects.</p

Neel probability and spin correlations in some nonmagnetic and nondegenerate states of hexanuclear antiferromagnetic ring Fe6: Application of algebraic combinatorics to finite Heisenberg spin systems

The spin correlations \omega^z_r, r=1,2,3, and the probability p_N$ of finding a system in the Neel state for the antiferromagnetic ring Fe(III)6 (the so-called `small ferric wheel') are calculated. States with magnetization M=0, total spin 0<=S<=15 and labeled by two (out of four) one-dimensional irreducible representations (irreps) of the point symmetry group D_6 are taken into account. This choice follows from importance of these irreps in analyzing low-lying states in each S-multiplet. Taking into account the Clebsch--Gordan coefficients for coupling total spins of sublattices (SA=SB=15/2) the global Neel probability p*_N can be determined. Dependencies of these quantities on state energy (per bond and in the units of exchange integral J) and the total spin S are analyzed. Providing we have determined p_N(S) etc. for other antiferromagnetic rings (Fe10, for instance) we could try to approximate results for the largest synthesized ferric wheel Fe18. Since thermodynamic properties of Fe6 have been investigated recently, in the present considerations they are not discussed, but only used to verify obtained values of eigenenergies. Numerical results re calculated with high precision using two main tools: (i) thorough analysis of symmetry properties including methods of algebraic combinatorics and (ii) multiple precision arithmetic library GMP. The system considered yields more than 45 thousands basic states (the so-called Ising configurations), but application of the method proposed reduces this problem to 20-dimensional eigenproblem for the ground state (S=0). The largest eigenproblem has to be solved for S=4; its dimension is 60. These two facts (high precision and small resultant eigenproblems) confirm efficiency and usefulness of such an approach, so it is briefly discussed here.Comment: 13 pages, 7 figs, 5 tabs, revtex

“Magnetic Force Microscopy and Energy Loss Imaging of Superparamagnetic Iron Oxide Nanoparticles”

We present quantitative, high spatially resolved magnetic force microscopy imaging of samples based on 11 nm diameter superparamagnetic iron oxide nanoparticles in air at room temperature. By a proper combination of the cantilever resonance frequency shift, oscillation amplitude and phase lag we obtain the tip-sample interaction maps in terms of force gradient and energy dissipation. These physical quantities are evaluated in the frame of a tip-particle magnetic interaction model also including the tip oscillation amplitude. Magnetic nanoparticles are characterized both in bare form, after deposition on a flat substrate, and as magnetically assembled fillers in a polymer matrix, in the form of nanowires. The latter approach makes it possible to reveal the magnetic texture in a composite sample independently of the surface topography