Screening of magnetic fields by superconducting and hybrid shields with circular cross-section

The use of superconducting (SC) materials is crucial for shielding quasi-static magnetic fields. However, the frequent requisite of space-saving solutions with high shielding performance requires the development of a 3D modelling procedure capable of predicting the screening properties for different orientations of the applied field. In this paper, we exploited a 3D numerical model based on a vector potential formulation to investigate the shielding ability of SC screens with cylindrical symmetry and a height/diameter aspect ratio close to unity, without and with the superimposition of a ferromagnetic (FM) circular shell. The chosen materials were MgB2 and soft iron. First, the calculation outcomes were compared with the experimental data obtained on different shielding arrangements, achieving a notable agreement in both axial-field (AF) and transverse-field (TF) orientations. Then, we used the thus validated modelling approach to investigate how the magnetic mitigation properties of a cup-shaped SC bulk can be improved by the superimposition of a coaxial FM cup. Calculations highlighted that the FM addition is very efficient in enhancing the shielding factors (SFs) in the TF orientation. Assuming a working temperature of 30 K and using a layout with the FM cup protruding over the SC one, shielding factors up to 8 times greater than those of the single SC cup were attained at low applied fields, reaching values equal or higher than 102 in the inner half of the shield. In the AF orientation, the same FM cup addition costs a modest worsening at low fields, but at the same time, it widens the applied field range, where SF ≥ 104 occurs near the close extremity of the shield, up over 1 T.

Исследование процесса коалесценции капель эмульсии в неоднородном переменном электрическом поле при наличии межфазной асфальтеновой пленки на границе раздела масло-вода

The behavior of a water-in-oil emulsion stabilized with asphaltenes under the action of an inhomogeneous alternating electric field has been studied. The experimental technique is based on the use of microfluidics, optical microscopy, and high-speed video filming. Quantitative estimates of the parameters characterizing the dynamics of the destruction of the emulsion, depending on the frequency and amplitude of the applied field, are obtained. The method will be useful in the development of effective methods for breaking emulsions and modifying existing technologies for separating oil emulsions into phases.

Penerapan Sistem Paket Murni Sebagai Metode Efisiensi Biaya Logistik Dalam Penyelenggaraan Pemilu Legislatif

Abstrak. Tujuan dari penulisan artikel ini adalah untuk memunculkan sebuah ide atau gagasan baru yang berupa sebuah metode dengan sebutan sistem paket murni. Metode ini metode muncul dengan latar belakang adanya beberapa persoalan yang terjadi pada penyelenggaraan pemilu serentak tahun 2019 lalu, salah satu penyebab persoalan itu adalah banyaknya jumlah penggunaan 5 (lima) kertas suara yang dicoblos berdampak pada banyak hal. Melalui penggunaan metode penelitian lapangan yang diterapkan, harapanya akan diperoleh sebuah data yang valid dengan tujuan untuk suatu temuan, pembuktian, dan pengembangan pengetahuan sehingga ke depannya akan bisa dipergunakan dalam melakukan pemecahan serta sebagai salah satu solusi untuk menyelesaikan sebuah permasalahan di lapangan. Hasil yang berupa ide atau gagasan dengan nama sistem paket murni ini nantinya bisa menjadi sebuah masukkan dalam merancang suatu kebijakan terkait tata cara pelaksanaan pemilu serentak yang akan diselenggarakan diwaktu yang akan datang untuk meminimalisir resiko persoalan yang akan terjadi dan mewujudkan efisiensi biaya logistik penyelenggaraan pemilu serentak. Abstract. The purpose of writing this article is to bring up a new idea or idea in the form of a method called a pure package system. This method emerged against the background of several problems that occurred in the holding of the simultaneous general election in 2019, one of the causes of the problem was the large number of uses of the 5 (five) ballot papers that were punched which had an impact on many things. Through the use of applied field research methods, it is hoped that valid data will be obtained with the aim of finding, proving, and developing knowledge so that in the future it can be used in solving problems and as a solution to solve a problem in the field. The results in the form of ideas or ideas with the name of a pure package system can later become an input in designing a policy related to the procedures for holding simultaneous elections to be held in the future to minimize the risk of problems that will occur and realize logistics cost efficiency in holding simultaneous elections.

Contact resistance, coupling and hysteresis loss measurements of ITER Poloidal Field joint in parallel applied magnetic field

The inter-strand contact resistance and AC losses were measured on an ITER PF Coil joint in a parallel applied AC magnetic field. In addition, the hysteresis loss was measured as a function of the angle with the applied magnetic field on a NbTi strand of the same type as in the joint with a Vibrating Sample Magnetometer (VSM). The AC loss measurements were performed at four applied field conditions for combinations of 0 or 1 T offset field and 0.2 or 0.4 T sinusoidal amplitude. The hysteresis loss of the joint was compared with the measured AC loss density of the NbTi strand for the same field conditions as the joint AC loss measurement but with varying the angle of the applied field. The subsequent cable twist angles affect the hysteresis loss since the critical current and penetration field depend on the angle of the applied field. It is found that 15.5° is an effective angle for the calculation of the hysteresis loss of joint when compared to the single strand measurement. The inter-strand contact resistance measurements cover all the typical strand combinations from the five cabling stages of the individual conductors, as well as the strand combinations across the two conductors to characterize the inter-strand including the copper sole resistivity. It’s the first time to measure the contact resistances and AC losses of the full-size ITER PF joint. By comparing the measured and simulated data in the JackPot-ACDC model, it’s also the first time to obtain the accurate inter-strand, inter-petal and strand to copper sole contact resistivities, which are the main input parameters for the further quantitative numerical analysis of the PF joints, in any current and magnetic field conditions.

»Philosophy […] Is the Theory of Education in Its Most General Phases«

»Philosophy […] Is the Theory of Education in Its Most General Phases«. Critical Remarks On Some Relationships between Philosophy and Education Following John Dewey In contrast to the widespread view that education is a subfield and field of application of practical philosophy, John Dewey understood philosophy altogether as a general theory of education. The article reconstructs this perspective in Dewey’s main pedagogical work »Democracy and Education« as well as in his 1929 paper »The Sources of a Science of Education«. Afterwards, two other relationships between philosophy and education will be contrasted, the so-called Isms approach and the configuration in which philosophy is one of the so-called ›foundation disciplines‹ dealing with education as an applied field. In an outlook, current changes in the relationship between philosophy and education will be discussed.

A Statistical-Mining Techniques’ Collaboration for Minimizing Dimensionality in Ovarian Cancer Data

A feature is a single measurable criterion to an observation of a process. While knowledge discovery techniques successfully contribute to many fields, however, the extensive required data processing could hinder the performance of these techniques. One of the main issues in processing data is the dimensionality of the data. Therefore, focusing on reducing the data dimensionality through eliminating the insignificant attributes could be considered one of the successful steps for raising the applied techniques’ performance. On the other hand, focusing on the applied field, ovarian cancer patients continuously suffer from the extensive analysis requirements for detecting the disease as well as monitoring the treatment progress. Therefore, identifying the most significant required analysis could be a positive step to reduce the emotional and financial suffering. This research aims to reduce the data dimensionality of the ovarian cancer disease and highlight the most significant analysis using the collaboration of clustering techniques and statistical techniques. The research succeeded to identify twelve significant analysis out of forty-four with a total of fourteen significant attributes for ovarian cancer data.

Influence of a High Static Magnetic Field on the Morphology of Primary Al3Fe Phase in Al-3%Fe Alloy

It had been done the experiments of the solidification on Al-Fe alloy under a high static magnetic field (10T). The effect of high magnetic field on the morphology of primary Al3Fe phase in Al-3%Fe alloy solidification structure has been investigated by analyzing the microstructures. The experimental results shew that the variation of the morphology of Al3Fe phase was obvious under a high static magnetic field, and them changed to particle-likes and short needles from needle-likes, and they were arranged in chains along the direction of magnetic field to form oriented layered structure. The critical nucleation work reduced and the nucleation rate increased under the applied field, and the magnetic interaction caused by the field can suppress the growth of needle-like Al3Fe phase, both of them resulted in the particle-likes and short needles grains of primary Al3Fe phase to nucleate and grow preferentially. Under the action of magnetic moment and the magnetic interaction force a high static magnetic field, the grains of Al3Fe rotated and then polymerized, and finally formed chain arrangements and layer structures.