Genetic Algorithm Optimisation of PID Controllers for a Multivariable Process

This project is about the design of PID controllers and the improvement of outputs in multivariable processes. The optimisation of PID controller for the Shell oil process is presented in this paper, using Genetic Algorithms (GAs). GAs are used to automatically tune PID controllers according to given specifications. They use an objective function, which is specially formulated and measures the performance of controller in terms of time-domain bounds on the responses of closed-loop process. A specific objective function is suggested that allows the designer for a single-input, single-output (SISO) process to explicitly specify the process performance specifications associated with the given problem in terms of time-domain bounds, then experimentally evaluate the closed-loop responses. This is investigated using a simple two-term parametric PID controller tuning problem. The results are then analysed and compared with those obtained using a number of popular conventional controller tuning methods. The intention is to demonstrate that the proposed objective function is inherently capable of accurately quantifying complex performance specifications in the time domain. This is something that cannot normally be employed in conventional controller design or tuning methods. Finally, the recommended objective function will be used to examine the control problems of Multi-Input-Multi-Output (MIMO) processes, and the results will be presented in order to determine the efficiency of the suggested control system

Hypocycloid-shaped hollow-core photonic crystal fiber Part I: Arc curvature effect on confinement loss

We report on numerical and experimental studies showing the influence of arc curvature on the confinement loss in hypocycloid-core Kagome hollow-core photonic crystal fiber. The results prove that with such a design the optical performances are strongly driven by the contour negative curvature of the core-cladding interface. They show that the increase in arc curvature results in a strong decrease in both the confinement loss and the optical power overlap between the core mode and the silica core-surround, including a modal content approaching true single-mode guidance. Fibers with enhanced negative curvature were then fabricated with a record loss-level of 17 dB/km at 1064 nm

Three-dimensional printing of porous load-bearing bioceramic scaffolds

This article reports on the use of the binder jetting three-dimensional printing process combined with sintering to process bioceramic materials to form micro- and macroporous three-dimensional structures. Three different glass-ceramic formulations, apatite–wollastonite and two silicate-based glasses, have been processed using this route to create porous structures which have Young’s modulus equivalent to cortical bone and average bending strengths in the range 24–36 MPa. It is demonstrated that a range of macroporous geometries can be created with accuracies of ±0.25 mm over length scales up to 40 mm. Hot-stage microscopy is a valuable tool in the definition of processing parameters for the sintering step of the process. Overall, it is concluded that binder jetting followed by sintering offers a versatile process for the manufacture of load-bearing bioceramic components for bone replacement applications

An infinite plate with a curvilinear hole having three poles with complex parameters

This paper covered the study of the boundary value problem for isotropic homogeneous perforated infinite elastic media. For this, we considered the problem of a thin infinite plate of specific thickness with a curvilinear hole where the origin lie outside the hole is conformally mapped outside a unit circle by means of a specific rational mapping . The complex variable method has been applied and it transforms the problem to the integrodifferential equation with Cauchy kernel that can be solved to find two complex potential functions which called Gaursat functions. Many special cases are discussed and established of these functions .Also, many applications and examples are considered. Moreover the components of stress , in each application , are computed

Problems of using a discount rate as monetary regulator

Originally published in Optics Letters on 01 May 2012 (ol-37-9-1430

Molecular identification of adenoviruses associated with respiratory infection in Egypt from 2003 to 2010.

BACKGROUND: Human adenoviruses of species B, C, and E (HAdV-B, -C, -E) are frequent causative agents of acute respiratory infections worldwide. As part of a surveillance program aimed at identifying the etiology of influenza-like illness (ILI) in Egypt, we characterized 105 adenovirus isolates from clinical samples collected between 2003 and 2010. METHODS: Identification of the isolates as HAdV was accomplished by an immunofluorescence assay (IFA) and confirmed by a set of species and type specific polymerase chain reactions (PCR). RESULTS: Of the 105 isolates, 42% were identified as belonging to HAdV-B, 60% as HAdV-C, and 1% as HAdV-E. We identified a total of six co-infections by PCR, of which five were HAdV-B/HAdV-C co-infections, and one was a co-infection of two HAdV-C types: HAdV-5/HAdV-6. Molecular typing by PCR enabled the identification of eight genotypes of human adenoviruses; HAdV-3 (n = 22), HAdV-7 (n = 14), HAdV-11 (n = 8), HAdV-1 (n = 22), HAdV-2 (20), HAdV-5 (n = 15), HAdV-6 (n = 3) and HAdV-4 (n = 1). The most abundant species in the characterized collection of isolates was HAdV-C, which is concordant with existing data for worldwide epidemiology of HAdV respiratory infections. CONCLUSIONS: We identified three species, HAdV-B, -C and -E, among patients with ILI over the course of 7 years in Egypt, with at least eight diverse types circulating

Arthropod-borne infections in the United Kingdom and Saudi Arabia

Arthropod vectors can transmit different diseases that are both a significant and widespread cause of mortality and morbidity in both human and wildlife species. However, further studies are required to identify the role of wildlife species as reservoir hosts for such infections. In some countries, such as Saudi Arabia, few studies have taken place whist in other regions individual species may have been neglected, such as red foxes (Vulpes vulpes) in the United Kingdom (UK).To address this paucity of knowledge, samples from different host species from the UK and Ireland (small rodents, red foxes, shrew and ticks species) and from Saudi Arabia Libyan jirds (Meriones libycus) and desert hedgehogs (Paraechinus aethiopicus) were collected and screened for different haemoparasites including Trypanosoma spp., Babesia/Theileria spp., and Bartonella spp. The data within this study describe different haemoparasite prevalences from these different hosts using PCR- based molecular typing tools. Trypanosoma infections were found in mall rodents from the UK and Ireland, however the presence of the invading bank vole (Myodes glareolus) in Ireland appears to have disrupted the host-parasite relationship between wood mice (Apodemus sylvaticus) and trypansomes. Babesia vulpes was identified in 134/392 (34%) of red foxes in the UK, suggesting that this potentially important parasite may be common in the UK. From Saudi Arabia, the data within this study showed that 49/121 (40%) of jirds were infected with Theileria spp. whereas 74/112 (66%) of hedgehogs harboured this parasite. Furthermore, Bartonella spp. infections were found in both jirds and hedgehogs from Saudi Arabia, where 73(60% of jirds and 15(13%) of hedgehogs were found to be infected with Bartonella. To compare the methods of PCR, real- time PCR and the newest technique, Next Generation Sequencing (NGS), a number of Ixodes ricinus tick samples were screened by NGS by analysing 16S rRNA gene and the resultant data were confirmed by either PCR or real-time PCR. Different bacterial infections were found in the samples including Anaplasma phagocytophilum, Borrelia graini, Candidatus Midichloria, and Rickettsia Helvetica. The comparison between these techniques revealed that NGS offers the potential to be a useful tool in screening hosts and vectors for infections, particularly in identifying novel infections

New Monotonic Properties for Solutions of Odd-Order Advanced Nonlinear Differential Equations

The present paper studies the asymptotic and oscillatory properties of solutions of odd-order differential equations with advanced arguments and in a noncanonical case. By providing new and effective relationships between the corresponding function and the solution, we present strict and new criteria for testing whether the studied equation exhibits oscillatory behavior or converges to zero. Our results contribute uniquely to oscillation theory by presenting some theorems that improve and expand upon the results found in the existing literature. We also provide an example to corroborate the validity of our proposed criteria

Deeply-trapped molecules in self-nanostructured gas-phase material

Since the advent of atom laser-cooling, trapping or cooling natural molecules has been a long standing and challenging goal. Here, we demonstrate a method for laser-trapping molecules that is radically novel in its configuration, in its underlined physical dynamics and in its outcomes. It is based on self-optically spatially-nanostructured high pressure molecular hydrogen confined in hollow-core photonic-crystal-fibre. An accelerating molecular-lattice is formed by a periodic potential associated with Raman saturation except for a 1-dimentional array of nanometer wide and strongly-localizing sections. In these sections, molecules with a speed of as large as 1800 m/s are trapped, and stimulated Raman scattering in the Lamb-Dicke regime occurs to generate high power forward and backward-Stokes continuous-wave laser with sideband-resolved sub-Doppler emission spectrum. The spectrum exhibits a central line with a sub-recoil linewidth of as low as 14 kHz, more than 5 orders-of-magnitude narrower than in conventional Raman scattering, and sidebands comprising Mollow triplet, molecular motional-sidebands and four-wave-mixing.Comment: 28 pages 1-12 for main manuscript 13-28 for Methodes and appendices 4 figures for Main manuscript 12 figures for the Methods par