A new integrable problem with a quartic integral in the dynamics of a rigid body

We consider the problem of motion of a rigid body about a fixed point under the action of an axisymmetric combination of potential and gyroscopic forces. We introduce a new integrable case, valid on zero level of the cyclic integral, that generalizes the known case of motion of a body in liquid due to Chaplygin and its subsequent generalization by Yehia. Apart from certain singular potential terms, the new case involves finite potential and gyroscopic forces, which admit physical interpretation as resulting from interaction of mass, magnetized parts and electric charges on the body with gravitational, electric and magnetic fields.Comment: This work will appear shortly in "Journal of Physics A: Mathematical and Theoretical

Study of the mechanical properties of a ceramics of orthopedic and dental use

The study of the preparation of ceramics is consisted in sintering a hardened cement, wich is composed of mixture of three calcium phosphates : tetracalcium phosphate (Ca4(PO4)2O), -tricalcium phosphate (-Ca3(PO4)2) and monocalcium phosphate (Ca(H2PO4)2.H2O).After wetting, the cement evolved towards an apatitic phase while hardening. To check the effect of certain factors on the resulting ceramics, a complete central composite design of four variables (liquid/solid ratio, stoichiometric coefficient of monocalcium phosphate, rate of increase in temperature and duration of landing of termpertaure) was set up. The equation of the model and optimal conditions were defined

La traducción de la poesía árabe clásica: Al-Mutanabbi

La tesis aborda el análisis y valoración de la traducción de la poesía del autor árabe Al-Mutanabbi titulada " Al-Mutanabbi Tiempo sin Tregua (101 poemas)" al español y realizada por Milagros Nuin y Clara Janés:(2007)

Studies on the biotransformation of chromium (VI) by methane oxidising bacteria.

Bioremediation is a promising and cost-effective technology widely used to clean up waste containing organic or inorganic contaminants. Cr(VI), the highest oxidation state of the metal chromium, is widely used in various industries, and is extremely toxic to animals and humans. Utilisation of chromium (Cr) reducing microbes and their products can enhance the efficiency of the process of detoxification of Cr(VI) to Cr(III).This study was conducted to investigate the microbial reduction of chromium [Cr(VI)] in general and the potential for biological treatment of Cr(Vl)-containing wastes in particular. Cr(VI) was transformed to non-toxic Cr(III) by Escherichia coli ATCC 33456. It was observed for the first time that the type I methanotrophic bacterium Methylococcus capsulatus (Bath) is able to reduce chromium (VI) to chromium (III), using methane as the carbon and energy source. The reaction occurred over a wide range of chromium (VI) concentrations (10-1,000 mg/1). The reaction was studied by a variety of techniques, including the diphenyl carbazide assay for chromium (VI), ion chromatography coupled to inductively coupled plasma atomic absorption spectroscopy (ICP-MS), transmission electron microscopy (TEM), energy dispersive X-ray spectroscopy (EDSX), X-ray absorption near-edge structure (XANES) and extended X-ray absorption fine structure (EXAFS). The results indicate that chromium(VI) reduction to chromium(III) is wholly or partly associated with the cells via coordination to phosphate moieties. BLAST searches using known chromate (Vl)-reducing enzymes from other bacteria indicated the presence of five potential chromate reductases in the genome sequence of M. capsulatus (Bath). Detailed bioinformatic analysis, including molecular modelling, indicates a possible mode of binding of chromium to two of these. The model type II methanotroph Methylosinus trichosporium OB3b did not reduce chromate (VI) in pure culture, and the future availability of the genome sequence of this organism may give additional clues to the origin of chromate(VI) reduction in M. capsulatus, via comparative genomics. Interestingly, however, mixed cultures of M. trichosporium and E. coli were able to reduce chromate(VI) using methane as the only source of reductant, presumably because the E. coli can scavenge nutrients from the M. trichosporium

Cloud Computing: The Future of IT Industry

As a result of the research processing in the computing field, a new computing model appeared based on the development of many computing models such as parallel computing, distributed computing, and grid computing. Many normal distributed computers collaborate of achieve a function like a super computer. The computation will be assigned to this super computer rather than local computer or remote server. This is the basic concept of cloud computing. However, there is a new implementation of cloud computing was introduced based on using the internet millions of computers connected to a super cloud. Cloud computing has several advantages such as; user does not need to worry about how the cloud runs, viruses, maintenance, etc. We would expect that cloud computing is going to reshape the IT industry. In this paper we discuss cloud computing from different angles such as concept, characteristics and classifications of cloud computing

Pemodelan Struktur Perlapisan Bawah Permukaan untuk Penentuan Bidang Gelincir pada Daerah Rawan Longsor. (Studi Kasus Ruas Jalan Nasional 005 Lakuan – Laulalang dan Ruas 006 Laulalang-Lingadan)

Characteristics of roads in Central Sulawesi at some point are an area of frequent landslides. The road segment in question, including the section 005 and section 006 which is a national road linking the province of Central Sulawesi and Gorontalo province. The link conditions that have often suffered landslides have disrupted access to transport and causing high transportation costs. This study aims to determine the geometry of the sliding plane at KM 509 and KM 513 using the method of geoelectric resistivity Wenner configuration with a path length measurement of 300 m and 5 m electrode spacing. The results of the study at two locations and modeling shows the layering structure resistivity value of which is at 100 Ωm - 300 Ωm and modeling results of 2-D geoelectric cross-section shows the sliding plane ground motion varies between 5 to 15 m. Value of resistance and sectional sliding obtained indicate that the location is vulnerable to landslides, and requires a comprehensive treatment to prevent landslides

Applications of Computer Simulations and Statistical Mechanics in Surface Electrochemistry

We present a brief survey of methods that utilize computer simulations and quantum and statistical mechanics in the analysis of electrochemical systems. The methods, Molecular Dynamics and Monte Carlo simulations and quantum-mechanical density-functional theory, are illustrated with examples from simulations of lithium-battery charging and electrochemical adsorption of bromine on single-crystal silver electrodes.Comment: 12 pages, 5 figures, Invited Book Chapte

Emotion and polarity prediction from Twitter

Classification of public information from microblogging and social networking services could yield interesting outcomes and insights into the social and public opinions towards different services, products, and events. Microblogging and social networking data are one of the most helpful and proper indicators of public opinion. The aim of this paper is to classify tweets to their classes using cross validation and partitioning the data across cities using supervised machine learning algorithms. Such an approach was used to collect real time Twitter microblogging data tweets towards mentioning iPad and iPhone in different locations in order to analyse and classify data in terms of polarity: positive or negative, and emotion: anger, joy, sadness, disgust, fear, and surprise. We have collected over eighty thousand tweets that have been pre-processed to generate document level ground-truth and labelled according to Emotion and Polarity. We also compared some approaches in order to measures the performance of K-NN, Nave Bayes, and SVM classifiers. We found that the K-NN, Nave Bayes, SVM, and ZeroR have a reasonable accuracy rates, however, the K-NN has outperformed the Nave Bayes, SVM, and ZeroR based on the achieved accuracy rates and trained model time. The K-NN has achieved the highest accuracy rates 96.58% and 99.94% for the iPad and iPhone emotion data sets using cross validation technique respectively. Regarding partitioning the data per city, the K-NN has achieved the highest accuracy rates 98.8% and 99.95% for the iPad and iPhone emotion data sets respectively. Regarding the polarity data sets using both cross validation and partitioning data per city, the K-NN achieved 100% for the all polarity datasets