Narrow Coils Research Articles

An exact model for a slitting problem in the steel industry

From an economic point of view, the steel industry plays an important role and, when it comes to responding to new challenges, innovation is a crucial factor. This paper proposes a mathematical methodology to solve the slitting problem in a steel company located in Europe. The slitting problem occurs when large width steel coils are slit into narrower coils, known as strips, to meet the requirements of the customers. A major challenge here is defining a slitting plan to fulfil all these requirements, as well as ongoing operational constraints and customer demands. The company looks for a reduction of the leftovers generated in the entire process, while maximising the overall accuracy of the orders. These leftovers may be used in the future as part of new orders provided they are able to respond to specific requirements, or otherwise they are discarded and considered as scrap. This paper introduces a novel mixed integer linear optimisation model to respond to a specific slitting problem. The model is validated with real data and it outperforms the results obtained by the company in different ways: by adjusting the orders that are to be served, by reducing the amount of scrap and by using the retails for future orders. Furthermore, the model is solved in only a few minutes, while the company needs several hours to prepare the scheduling in the current operating process.

Improving performance of induction-heated steam methane reforming

Abstract Induction heating may be an electrical solution for heating of catalytic reactors. Recent studies have shown that CoNi nanoparticles may act as both inductors for hysteresis heating and catalyst, such that they in an alternating magnetic field are able to drive the strongly endothermic steam methane reforming reaction with > 90% gas conversion at temperatures of ≈800 °C. However, lab-scale induction-heated reactors are limited by low energy transfer efficiency and previous work did not optimize the surrounding instrumentation. Here, we focused on the optimization of an induction setup for steam methane reforming. The performance of the reactor system was investigated through experiments at varying alternating magnetic field conditions, to evaluate the effect of frequency and coil geometry. The results from these experiments were modelled by a simple theoretical framework. Increasing the frequency of the alternating magnetic field from 68 kHz to 189 kHz was found to increase the energy transfer efficiency. Moreover, the energy transfer efficiency also increased when going from a short and wide coil with height to radius ratio of 3.8 to a long and narrow coil with height to radius ratio of 10.8. Overall, the energy transfer efficiency was increased from an initial 11% in the bench scale reactor setup, to 23% in the optimized version. Moreover, combining the bench scale results with the theoretical framework we extrapolated the data to large-scale systems. The analysis indicated that the energy efficiency of induction-heated steam reforming systems scaled to larger H2 capacities may be above 80%. This efficiency would allow the technology to be competitive with other electricity driven routes to hydrogen production when considering only the energy requirements.

Parathelohania iranica sp. nov. (Microsporidia: Amblyosporidae) infecting malaria mosquito Anopheles superpictus (Diptera: Culicidae): Ultrastructure and molecular characterization

Microsporidia are common pathogens of insects and sometimes are considered as a candidate in the biological control of mosquitoes. Recently a microsporidium infection was discovered in Anopheles superpictus (Diptera: Culicidae) larvae, in Iran. The responsible agent belonged to the genus Parathelohania (Microsporidia: Amblyosporidae). This study has been carried out to identify its identity at the species level.Fresh infected larvae were collected from the type locality, Kiar district, in Chahar Mahal and Bakhtiari province, at the central western of Iran. Superficial and the internal ultrastructure of the recovered spores were explored by scanning and transmission electron microscopy, respectively. Molecular techniques were also employed to amplify parts of its ssu rDNA. The obtained data were compared with the available information of congener species and other closely related microsporidia to elucidate evolutionary relationship.A small apical depression and two posterolateral ridges extending backward from a pear shaped anterior body mass were notable under scanning electron microscopy. Transmission electron microscopy revealed 2 broad and 3–4 narrow coils in the either side of spores, respectively. The sequence of a 1062 nucleotide fragment of ssu rDNA was determined by means of PCR technique.This study indicates that the microsporidium infecting An. superpictus differs from other previously described species in the genus Parathelohania. It means that the microsporidium infecting An. superpictus is a new species and hereby it is called Parathelohania iranica. Further work is necessary to clarify its life cycle and probable value in the biological control of mosquitoes.

Modelling electromagnetic induction via accelerated electron motion

The two forms of electromagnetic induction are generally referred to as motional and transformer induction, and although these phenomena have been observed and discussed for well over 150 years, certain aspects remain controversial in the scientific literature. It is well-known that an electromotive force (emf) is induced in a loop of wire encircling a long solenoid carrying alternating current. This is true however even in a region in which there is a negligibly small magnetic or electric field. Although the flux linking concept can explain the induced emf, more recent explanations utilise the concept of vector potential as the causal explanation of induction. In this present investigation, we propose that Weber’s force, based on inter-particle forces, provides a more fundamental explanation. The induced emf is measured directly across a closely wound, 1000 turn narrow coil encircling a long solenoid carrying alternating current. Weber’s force formula has been adapted to the case of transformer induction by treating the solenoid as a stack of current loops and applying the principle of superposition. Analytical calculation is also included for the application of Faraday’s law. Close agreement with experimentally measured values is demonstrated in all cases for low-frequency induction up to around 5 kHz.

Fast and Precise Method for Inductance Calculation of Coaxial Circular Coils With Rectangular Cross Section Using the One-Dimensional Integration of Elementary Functions Applicable to Superconducting Magnets

A new and extremely fast and precise method for calculating mutual inductance between coaxial circular coils in air with rectangular cross section and uniform current densities is presented. It is thoroughly compared with all recently published methods in the same computing environment, and the results confirm the aforementioned. Along with the high accuracy and low computational time, the emphasis is put on the easiness of implementing the method, using only the elementary functions. The method can be used in all combinations of the coils' radii and heights, from narrow coils to coils with extremely large radii, such as the coils used in superconducting magnets. Excellent numerical stability and agreement with professional software was found in all testing cases.

An Insertable Nonlinear Gradient Coil for Phase Compensation in SEA Imaging

In magnetic resonance imaging with array coils with many elements, as the radiofrequency (RF) coil dimensions approach the voxel dimensions, the phase gradient due to the magnetic field pattern of the coil causes signal cancellation within each voxel. In single echo acquisition (SEA) imaging with coil arrays, a gradient pulse can be applied to compensate for this effect. However, because RF coil phase varies with distance from the array and reverses on opposite sides of a dual-sided array, this method of phase compensation can be optimized for only a single slice at a time. In this study, a nonlinear gradient coil was implemented to provide spatially varying phase compensation to offset the coil phase with slice position for dual-sided arrays of narrow coils. This nonlinear gradient coil allows the use of one phase compensation pulse for imaging multiple slices through a slab, and, importantly, is shown to enable simultaneous SEA imaging from opposite sides of a sample using a dual-sided receive array.

Finite Element Modeling of Shear-Slitting Process

Shear-slitting is a sheet metal cutting process used for dividing coiled sheet into narrower coils. In this paper, a two-dimensional finite element model was developed for the calculation of the shear-slitting process by using ABAQUS/Explicit. The shear failure criteria and the element-delete method were adopted to model the material separation. Mass scaling was used to reduce the solution time. The effect of clearance on the burr height was investigated. The simulation results show good agreement with experimental results. The critical clearance values was suggested for decreasing the burr.

An improved element design for 64‐channel planar imaging

Investigation of highly accelerated MRI has developed into a lively corner in the hardware and methodology arena in recent years. At the extreme of (one-dimensional) acceleration, our group introduced Single Echo Acquisition (SEA) imaging, in which the need to phase encode a 64×N(readout) image is eliminated and replaced with the well-localized spatial information obtained from an array of 64 very narrow, long, parallel coils. The narrow coil width (2mm) that facilitates this is accompanied by a concomitant constraint on the useful imaging depth. This note describes a 64-element planar array, constructed within the same 8×13cm total footprint as the original SEA array, still enabling full acceleration in one dimension, but with an element design modified to increase the imaging depth. This was accomplished by lowering the outer conducting legs of the planar pair with respect to the center conductor and adding a geometric decoupling configuration away from the imaging field of view. The element has been called a dual-plane pair in that the current carrying rungs in the imaging FOV function exactly as the planar pair, but are simply placed in two separate planes (sides of PCB in this case).

THE DEVELOPMENT OF CORRUGATED POTTERY IN SOUTHWESTERN COLORADO

Archaeological research has documented the broad outlines of the development of corrugated utility pottery from plain and neck-banded antecedents. However, a reliance on typological descriptions has obscured the technological details of this development. An attribute analysis of six well-dated utility-ware assemblages from southwestern Colorado indicates that corrugation appeared first in this region during the eighth century A. D. as wide, non-overlapping coils left unsmoothed around jar necks. During the ninth and tenth centuries, the variety and frequency of neck-banding increased with the introduction of narrower coils, overlapping of adjacent coils, and incising and indenting of coil surfaces. By the early eleventh century, one recent neck-banding variant, narrow, substantially overlapped and indented coils, replaced almost all others, and was extended over the entire exterior surface of jars for the first time. Performance benefits of this full-body, indented corrugation may explain its rapid adoption in southwestern Colorado.

Planar yoke write head for half-micron track width

Required basic features as to 30 Gbpsi recording density for write head are good overwrite O/W, good nonlinear transition shift NLTS, and high frequency performance in half-micron track width. To achieve these, we have developed a new structure, planar yoke write head, combined with SV read head, which features narrow track (physical write track width=0.35 /spl mu/m), narrow coil pitch (1.3 /spl mu/m coil pitch) for short yoke length (16 /spl mu/m yoke length), one-layer coil design, and used flat yoke pole while succeeding in the advantages of our current stitched pole write head. Regarding the write performance, we compared planar yoke head with current stitched pole head by simulation and actual measurement.

Guidance in vitro of the pollen tube to the naked embryo sac of torenia fournieri

The precise guidance of the pollen tube to the embryo sac is critical to the successful sexual reproduction of flowering plants. We demonstrate here the guidance of the pollen tube to the embryo sac in vitro by using the naked embryo sac of Torenia fournieri, which protrudes from the micropyle of the ovule. We developed a medium for culture of both the ovule and the pollen tube of T. fournieri and cocultivated them in a thin layer of solid medium. Although pollen tubes that had germinated in vitro passed naked embryo sacs, some pollen tubes that grew semi-in vitro through a cut style arrived precisely at the site of entry into the embryo sac, namely, the filiform apparatus of the synergids. When pollen tubes were unable to enter the embryo sac, they continuously grew toward the same filiform apparatus, forming narrow coils. Pollen tubes selectively arrived at complete, unfertilized embryo sacs but did not arrive at those of heat-treated ovules or those with disrupted synergids. These results convincingly demonstrate that pollen tubes are specifically attracted to the region of the filiform apparatus of living synergids in vitro.

Some ultrastructural data on Microsporidium ceylonensis, a cause of corneal microsporidiosis.

Sections of corneal tissue infected with Microsporidium ceylonensis were restained or processed for electron microscopy. Confirmation was obtained that the parasite develops in macrophages and that spores are uninucleate. New information is provided that sporoblasts and spores develop synchronously within a membrane in the host cell, spores have an anisofilar polar tube of 6-10 wide coils and 2-3 narrow coils and details are given of the spore wall and internal organisation. The parasite was compared on the one hand with Encephalitozoon, which exhibits asynchronous intravacuolar development of merogonic and sporogonic stages and has spores with isofilar polar tubes and on the other hand with species reported from mammals, of which the sporogonic stages develop synchronously within sporophorous vesicles and the spores have anisofilar polar tubes. Even so, a generic emplacement could not be established. Attention is drawn to the similarities between M. ceylonensis and Nosema sp. described from the cornea of a woman in Botswana.

Light and electron microscope study on Gurleya daphniae sp. nov. (Microspora, Gurleyidae), a parasite of Daphnia pulex (Crustacea, Phyllopoda)

Summary The life cycle of a new microsporidian species parasitizing in the epidermis of the cladoceran Daphnia pulex from the southeast region of Austria is described using light and electron microscopical methods. Merogonial stages have one or two single nuclei. Sporonts produce the sporophorous vesicle and normally develop into lobed sporongial Plasmodia with four single nuclei. These plasmodia divide into four monokaryotic sporoblasts. The envelope of the sporophorous vesicle is of about the same thickness as the plasma membrane. Spores are pyriform, monokaryotic and measure between 3.8 × 2.3 and 4.6 × 2.6 μm. The polaroplast is composed of two parts. The anterior part is lamellar, the posterior part consists of sac-like structures. The polar filament is anisofilar and consists of 3–4 thick and 2–5 narrow coils. The spore wall is up to 415 nm thick and composed of three layers. The episporontal space contains tubules and fibres. Abnormal spores with regard to size, shape and number within the envelope frequently can be observed. Because of the differences to microsporidian species previously reported from the epidermis of cladocerans the parasite of Daphnia pulex is described as a new species and named Gurleya daphniae.

A light- and electron-microscopic study of Amblyospora egypti n.sp. infecting Culex pipiens in Egypt

A microsporidium was found infecting the fat body of larvae and adults of both sexes of Culex pipiens in Egypt. Developmental stages were found in larvae but only masses of spores were present in adults. The infection was easily visible in live mosquito larvae, as one or two blocks of opaque whitish fat body visible through the cuticle in each segment. Meronts were rounded cells, which were bounded by an unthickened unit membrane and divided by binary fission (rarely into four). At the onset of sporogony the surface membrane was thickened by electron dense deposits. This coat was sloughed off to form the sporophorous vesicle, the separation from the sporont surface being effected by the secretion of metabolic products into the sporophorous vesicle cavity. Division within the vesicle gave rise to eight uninucleate sporoblasts, then uninucleate spores. Spores exhibited an exospore of two membrane-like layers and a subtending layer of moderate electron density, appearing as eight to ten strata separated by fine lines and permeated by amorphous material, and an electron lucent endospore. The polar tube was anisofilar with 3-4 broad coils and 4-3 narrow coils. The development and spore structure were in accord with the genus Amblyospora Hazard and Oldacre, 1975 and, on the basis of spore size and number of coils of the polar tube, it is considered to be a new species, Amblyospora egypti n.sp.

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