On integrability of some bi-Hamiltonian two field systems of PDE

We continue the study of integrability of bi-Hamiltonian systems with a compatible pair of local Poisson structures (H_0,H_1), where H_0 is a strongly skew-adjoint operator. This is applied to the construction of some new two field integrable systems of PDE by taking the pair (H_0,H_1) in the family of compatible Poisson structures that arose in the study of cohomology of moduli spaces of curves.Comment: 30 page

A new approach to the Lenard-Magri scheme of integrability

We develop a new approach to the Lenard-Magri scheme of integrability of bi-Hamiltonian PDE's, when one of the Poisson structures is a strongly skew-adjoint differential operator.Comment: 20 page

Analysis and Application of Advanced Control Strategies to a Heating Element Nonlinear Model

open4siSustainable control has begun to stimulate research and development in a wide range of industrial communities particularly for systems that demand a high degree of reliability and availability (sustainability) and at the same time characterised by expensive and/or safety critical maintenance work. For heating systems such as HVAC plants, clear conflict exists between ensuring a high degree of availability and reducing costly maintenance times. HVAC systems have highly non-linear dynamics and a stochastic and uncontrollable driving force as input in the form of intake air speed, presenting an interesting challenge for modern control methods. Suitable control methods can provide sustainable maximisation of energy conversion efficiency over wider than normally expected air speeds and temperatures, whilst also giving a degree of “tolerance” to certain faults, providing an important impact on maintenance scheduling, e.g. by capturing the effects of some system faults before they become serious.This paper presents the design of different control strategies applied to a heating element nonlinear model. The description of this heating element was obtained exploiting a data driven and physically meaningful nonlinear continuous time model, which represents a test bed used in passive air conditioning for sustainable housing applications. This model has low complexity while achieving high simulation performance. The physical meaningfulness of the model provides an enhanced insight into the performance and functionality of the system. In return, this information can be used during the system simulation and improved model based and data driven control designs for tight temperature regulation. The main purpose of this study is thus to give several examples of viable and practical designs of control schemes with application to this heating element model. Moreover, extensive simulations and Monte Carlo analysis are the tools for assessing experimentally the main features of the proposed control schemes, in the presence of modelling and measurement errors. These developed control methods are also compared in order to evaluate advantages and drawbacks of the considered solutions. Finally, the exploited simulation tools can serve to highlight the potential application of the proposed control strategies to real air conditioning systems.openTurhan, T.; Simani, S.; Zajic, I.; Gokcen Akkurt, G.Turhan, T.; Simani, Silvio; Zajic, I.; Gokcen Akkurt, G

Genotypic variation in growth and physiological responses of common bean (Phaseolus vulgaris L.) seedlings to flooding

Tolerance to flooding stress in root regions of some common bean genotypes (Beyaz Fasulye, Boncuk Sırık, Kökez, Oturak and Sırık) was investigated in terms of morphological and physiological. Plants were grown in a plant growth chamber at 26/18°C (day/night) temperature with RH 70% and 450 m-2 s-1 light intensity. Seedlings were exposed to flooding stress for 3 days when the plants had developed 3 to 4 true leaves. The results obtained showed that root dry weight and leaf area were reduced significantly by flooding treatment. The changes in leaf area showed differences between genotypes. It was found that flooding treatment did not affect the leaf relative water content (RWC) value. Flooding treatment decreased total chlorophyll content significantly. It was observed that some increases and decreases in the total sugar and lipid peroxidation (MDA) contents in root and leaf parts depend on genotypes and treatment. Beside that cell membrane injury and influence of flooding for each genotype were determined measuring the electrical conductivity. It was determined that the tolerance to flooding of five evaluated common bean genotypes, were change depending on root and leaf part. The results also showed that different genotypes responded differently to excess water in the soil, which could be linked to variation in growth and physiological responses. According to the evaluation, these results possibly suggest that ‘Boncuk Sırık’ ‘was relatively tolerant genotype, whereas ‘Sırık’ and ‘Kökez’ were determined as more sensitive genotypes.Key words: Phaseolus vulgaris L., common bean, excess water stress, flooding, lipid peroxidation, membrane injury, waterlogging

Sensitivities Of Citrobacter, Proteus And Providencia Isolates To Sulbactam-ampicillin, Trimethoprim-S Ulfamethoxazol And Ticarcillin-Clavulanic Acid Antibiotics

Gram negative bacterias which belong to Enterobacteriaceae family which is critically important as a matter of human health, are comperatively prevalent in nature and foods. Infections formed by bacterias resistant to antibiotics significantly cause mortality and economical losses. Sensitivities of gram-negative bacterias isolated from miscellaneous samples to sulbactamampicillin, trimethoprim-sulfamethoxazol and ticarcillin-clavulanic acid were analysed. In this study, Proteus is primary isolated microorganism with % 52,08. It was determined that Proteus types are proportionally 86,66% sensitive to Trimethoprim-Sulfamethoxazol and 76% resistant to Sulbactam-Ampicillin . Citrobacter is the secondary isolated microorganism (31,25%). It was determined that Citrobacter types were 86,66% sensitive to Trimethoprim-Sulfamethoxazol and % 73,3 resistant to Sulbactam-Ampicillin. Providencia types which are thirdly isolated microorganism (16%), For Providencia types, Trimethoprim-Sulfamethoxazol were determined as the most effective antibiotic again with 86,66% sensitivity. Resistance to Sulbactam- Ampicillin was however, found to be 76%. In conclusion, it is very important to conduct sensitivity tests in choosing antibiotics for chemotherapy of infections. Trimethoprim-Sulfamethoxazol is recommended in the empiric treatment of urinary tract infections in our environment Keywords: Enterobacter, sensitive, SXT, TĐM, SAM African Journal of Clinical and Experimental Microbiology Vol. 10 (2) 2009: pp. 88-9

Frequency-tunable metamaterials using broadside-coupled split ring resonators

We present frequency tunable metamaterial designs at terahertz (THz) frequencies using broadside-coupled split ring resonator (BC-SRR) arrays. Frequency tuning, arising from changes in near field coupling, is obtained by in-plane horizontal or vertical displacements of the two SRR layers. For electrical excitation, the resonance frequency continuously redshifts as a function of displacement. The maximum frequency shift occurs for displacement of half a unit cell, with vertical displacement resulting in a shift of 663 GHz (51% of f0) and horizontal displacement yielding a shift of 270 GHz (20% of f0). We also discuss the significant differences in tuning that arise for electrical excitation in comparison to magnetic excitation of BC-SRRs

A new integrable generalization of the Korteweg - de Vries equation

A new integrable sixth-order nonlinear wave equation is discovered by means of the Painleve analysis, which is equivalent to the Korteweg - de Vries equation with a source. A Lax representation and a Backlund self-transformation are found of the new equation, and its travelling wave solutions and generalized symmetries are studied.Comment: 13 pages, 2 figure

Results from an ethnographically-informed study in the context of test driven development

Background: Test-driven development (TDD) is an iterative software development technique where unit tests are defined before production code. Previous studies fail to analyze the values, beliefs, and assumptions that inform and shape TDD. Aim: We designed and conducted a qualitative study to understand the values, beliefs, and assumptions of TDD. In particular, we sought to understand how novice and professional software developers, arranged in pairs (a driver and a pointer), perceive and apply TDD. Method: 14 novice software developers, i.e., graduate students in Computer Science at the University of Basilicata, and six professional software developers (with one to 10 years work experience) participated in our ethnographicallyinformed study. We asked the participants to implement a new feature for an existing software written in Java. We immersed ourselves in the context of the study, and collected data by means of contemporaneous field notes, audio recordings, and other artifacts. Results: A number of insights emerge from our analysis of the collected data, the main ones being: (i) refactoring (one of the phases of TDD) is not performed as often as the process requires and it is considered less important than other phases, (ii) the most important phase is implementation, (iii) unit tests are almost never up-to-date, (iv) participants first build a sort of mental model of the source code to be implemented and only then write test cases on the basis of this model; and (v) apart from minor differences, professional developers and students applied TDD in a similar fashion. Conclusions: Developers write quick-and-dirty production code to pass the tests and ignore refactoring.Copyright is held by the owner/auther(s)

Adsorption of methylene blue from aqueous solutions by pyrolusite ore

In this study, the adsorption of methylene blue dye was examined by using pyrolusite ore as a low-cost alternative adsorbent source. Pyrolusite, which contains mainly MnO2, is a manganese ore. The effects of the initial concentration of dye, contact time, initial pH of solution, adsorbent dosage, stirring speed of solution, and average particle size of adsorbent on the adsorption of methylene blue were studied. It was found that the percentage of the adsorbed dye increased with increasing the amount of pyrolusite. While the initial dye concentration, initial pH, contact time, stirring speed, particle size, and adsorbent dosage were 25 ppm, 6, 90 min, 250 rpm, 63 µm, and 12 g/l, respectively, the efficiency of dye adsorption on pyrolusite ore was 99%. The isotherm and kinetic studies relating to this adsorption process were also made. It was found that the equilibrium data followed the Langmuir isotherm model while the kinetic of process could be described by the pseudo-second order kinetic model