HATHOR – HAdronic Top and Heavy quarks crOss section calculatoR

We present a program to calculate the total cross section for top-quark pair production in hadronic collisions. The program takes into account recent theoretical developments such as approximate next-to-next-to-leading order perturbative QCD corrections and it allows for studies of the theoretical uncertainty by separate variations of the factorization and renormalization scales. In addition it offers the possibility to obtain the cross section as a function of the running top-quark mass. The program can also be applied to a hypothetical fourth quark family provided the QCD couplings are standard.

Program summary

Program title: HathorCatalogue identifier: AEID_v1_0Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEID_v1_0.htmlProgram obtainable from: CPC Program Library, Queen's University, Belfast, N. IrelandLicensing provisions: GNU GPL 3No. of lines in distributed program, including test data, etc.: 5405No. of bytes in distributed program, including test data, etc.: 327 718Distribution format: tar.gzProgramming language: C++, Fortran, JavaComputer: Standard PCs (x86, x86_64 processors)Operating system: LinuxRAM: 256 MBClassification: 11.1External routines: Interface to LHAPDF for the user's choice of parton distribution functions, see http://projects.hepforge.org/lhapdf/Nature of problem: Computation of total cross section in perturbative QCD.Solution method: Numerical integration of hard parton cross section convoluted with parton distribution functions.Running time: A few seconds to a few minutes on standard desktop PCs or notebooks, depending on the chosen options.     

Algorithms for Indicating the Beginning of Accidents Based on the Estimate of the Density Distribution Function of the Noise of Technological Parameters

A technology has been developed, which allows for calculating the probability density function of noise, its maximum and inflection points, using the discrete values of a signal corrupted by an additive random noise. Computational experiments have been conducted. It has been demonstrated that knowledge of those characteristics of noise allows systems of monitoring, control, diagnostics, forecasting, identification, management, etc. to register not only the initial period of fault origin, but also the moment when preventive maintenance measures, routine or major overhaul works are required.     

Radiation grafting of N,N-dimethylaminoethylmethacrylate and 4-vinylpyridine onto polypropylene by the one- and two-step methods

Summary Radiation grafting of N,N-dimethylaminoethylmethacrylate (DMAEMA) and 4-vinylpyridine (4-VP) from the 50% monomers solutions in toluene and dichloroethane onto polypropylene (PP) films was carried by their mutual γ-irradiation (one-step method). In the two-step method, the grafting of DMAEMA or 4-VP from their solutions in toluene was performed onto PP modified preliminary with the other polymer (poly4-VP or polyDMAEMA). It has been found that chemical structure of PP modified with the first grafted polymer affected the efficiency of the other monomer grafting by the second step. Received: 30 April 2001/Revised version: 21 October 2001/Accepted: 28 November 2001     

Dynamic data mining technique for rules extraction in a process of battery charging

Battery charging controllers design and application is a growing industry direction. Fast and efficient charging of battery packs is a problem which is difficult and often expensive to solve using conventional techniques. The majority of existing works on intelligent charging systems are based on expert knowledge and heuristics. Not all features of the desired charging behavior can be attained by the hard-wired logic implemented by expert generated rules. Because the battery charging is a highly dynamic process and the chemical technology a battery uses varies significantly for different battery types, data mining technique can be of real importance for extracting the charging rules from the large databases, especially when the charging logic is to be continuously changed during the life of the battery dependent on the type and characteristics of the battery and utilization conditions. In this paper we use soft computing-based data mining technique for extraction of control rules for effective and fast battery charging process. The obtained rules were used for NiCd battery charging. The comparative performance evaluation was done among the existing charging control methods and the proposed system, which demonstrated a significant increase of performance (minimum charging time and minimum overheating) using the soft computing-based approach.     

A comparative radiation degradation of some aromatic polyesters

Summary A comparative investigation of radiation degradation of poly(1,4-butylene terephthalate), PBT; poly(ethylene terephthalate), PET; and poly(ethylene 2,6-naphthalene-dicarboxylate), PEN, was carried out. These polyesters were irradiated under vacuum at doses from 0.5 to 4 MGy. Data on solubility of the irradiated polyesters revealed absence of cross-linking. Molecular weights of PBT and PET decreased noticeably after irradiation, and radiation-chemical yields of destruction were quantified. NMR and UV spectra revealed changes in molecular structure upon irradiation of PBT. Efficiency and mechanism of radiation degradation of PBT, PET and PEN were discussed.     

Decision Making with Second‐Order Imprecise Probabilities

In decision analysis, uncertainty is usually described in the framework of probability. However, a large number of experimental and theoretical studies showed that a single nature of probability does not accurately capture human preferences. To avoid this drawback, they use imprecise probabilities. But, as decision maker is usually uncertain about first‐order imprecise probabilities, imprecise hierarchical probability models are used. For most of such models, the second levels are precise. There also exist studies on two‐level imprecise hierarchical models, which use imprecise probabilities or possibilities at the second level. Most of these works are based on lower prevision theory leading to a large number of optimization problems. In the present paper, we propose an imprecise hierarchical decision‐making model where the first and the second level are described by interval probabilities. The method associates with the construction of a nonadditive measure as a lower prevision and uses this capacity in Choquet integral for constructing a utility function.     

Photoelectrochemical properties of TiO<Subscript>2</Subscript>/CdS heterostructures

The photoelectrochemical properties of TiO₂, CdS, and TiO₂/CdS anodes have been studied. The results demonstrate that, under illumination, CdS anodes are subject to photocorrosion, and Cd²⁺ ions pass into solution. Corrosion-resistant films of TiO₂ prevent CdS photocorrosion, and the CdS/TiO₂ system exhibits good photosensitivity in the visible range.     

Indentation fracture toughness of single-crystal Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript> topological insulators

Bismuth telluride (Bi₂Te₃) is one of the most important commercial thermoelectric materials. In recent years, the discovery of topologically protected surface states in Bi chalcogenides has paved the way for their application in nanoelectronics. Determination of the fracture toughness plays a crucial role for the potential application of topological insulators in flexible electronics and nanoelectromechanical devices. Using depth-sensing nanoindentation tests, we investigated for the first time the fracture toughness of bulk single crystals of Bi₂Te₃ topological insulators, grown using the Bridgman-Stockbarger method. Our results highlight one of the possible pitfalls of the technology based on topological insulators.

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Electric Conductivity and Dielectric Dispersion of Polyvinylchloride–Graphite Composites

The dielectric properties of polyvinylchloride–graphite composites in a wide range of temperatures (20–150°C) and frequencies (25–10⁶ Hz) have been described and analyzed. Polyvinylchloride–graphite composites have been synthesized in accordance with powder technology by hot pressing in a hydraulic press and subsequent rapid cooling in a water–ice mixture (quenching mode). The dielectric permeability and electric conductivity of the polyvinylchloride–graphite composite system obey the power law of the percolation theory. The percolation threshold of these composites is ~6.35 vol % of graphite. At a certain concentration of graphite, polyvinylchloride–graphite composites exhibit high dielectric permeability, significant losses, and high dc and ac electric conductivity. With anincrease in the applied-field frequency, the permeability decreases, while theelectric conductivity, conversely, increases. It has been shown that the main mechanism of electric conductivity in polyvinylchloride–graphite insulators is barrier hopping; according to this mechanism, electrons hop over states localized in the vicinity of the Fermi level. In addition, the temperature and frequency dispersions of ε' and tanδ have been discussed; the specific features of the dispersion curves have been revealed.