Order Reduction of the Radiative Heat Transfer Model for the Simulation of Plasma Arcs

An approach to derive low-complexity models describing thermal radiation for the sake of simulating the behavior of electric arcs in switchgear systems is presented. The idea is to approximate the (high dimensional) full-order equations, modeling the propagation of the radiated intensity in space, with a model of much lower dimension, whose parameters are identified by means of nonlinear system identification techniques. The low-order model preserves the main structural aspects of the full-order one, and its parameters can be straightforwardly used in arc simulation tools based on computational fluid dynamics. In particular, the model parameters can be used together with the common approaches to resolve radiation in magnetohydrodynamic simulations, including the discrete-ordinate method, the P-N methods and photohydrodynamics. The proposed order reduction approach is able to systematically compute the partitioning of the electromagnetic spectrum in frequency bands, and the related absorption coefficients, that yield the best matching with respect to the finely resolved absorption spectrum of the considered gaseous medium. It is shown how the problem's structure can be exploited to improve the computational efficiency when solving the resulting nonlinear optimization problem. In addition to the order reduction approach and the related computational aspects, an analysis by means of Laplace transform is presented, providing a justification to the use of very low orders in the reduction procedure as compared with the full-order model. Finally, comparisons between the full-order model and the reduced-order ones are presented

Radiative Heat Transfer and Effective Transport Coefficients

The theory of heat transfer by electromagnetic radiation is based on the radiative transfer equation (RTE) for the radiation intensity, or equivalently on the Boltzmann transport equation (BTE) for the photon distribution. We focus in this review article, after a brief overview on different solution methods, on a recently introduced approach based on truncated moment expansion. Due to the linearity of the underlying BTE, the appropriate closure of the system of moment equations is entropy production rate minimization. This closure provides a distribution function and the associated effective transport coefficients, like mean absorption coefficients and the Eddington factor, for an arbitrary number of moments. The moment approach is finally illustrated with an application of the two-moment equations to an electrical arc

A novel method to assess human population exposure induced by a wireless cellular network

<p>This paper presents a new metric to evaluate electromagnetic exposure induced by wireless cellular networks. This metric takes into account the exposure induced by base station antennas as well as exposure induced by wireless devices to evaluate average global exposure of the population in a specific geographical area. The paper first explains the concept and gives the formulation of the Exposure Index (EI). Then, the EI computation is illustrated through simple phone call scenarios (indoor office, in train) and a complete macro urban data long-term evolution scenario showing how, based on simulations, radio-planning predictions, realistic population statistics, user traffic data, and specific absorption rate calculations can be combined to assess the index.</p

Probing the light induced dipole-dipole interaction in momentum space

We theoretically investigate the mechanical effect of the light-induced dipole-dipole interaction potential on the atoms in a Bose-Einstein condensate. We present numerical calculations on the magnitude and shape of the induced potentials for different experimentally accessible geometries. It is shown that the mechanical effect can be distinguished from the effect of incoherent scattering for an experimentally feasible setting

Pengaruh Perilaku Sosial Ekonomi Dan Manajemen Strategi Adaptasi Lahan Tadah Hujan Terhadap Hasil Panen Tembakau Di Magetan

Penelitian ini membahas tentang pengaruh perilaku sosial ekonomi dan strategi pengelolaan adaptasi lahan tadah hujan terhadap hasil panen. Penelitian ini berlokasi di Magetan dengan seluruh petani tembakau di Desa Pacalan, Kecamatan Plaosan, Desa Getasanyar dan Desa Sidomulyo. Untuk menjawab penelitian ini menggunakan pendekatan metode campuran. Pada variabel perilaku sosial ekonomi mempengaruhi hasil panen dengan nilai signifikan &gt; 0,000 dengan sub variabel umur, pengalaman, tanggung jawab keluarga, luas lahan, dan pendapatan. Pada variabel pengelolaan, strategi adaptasi lahan tadah hujan mempengaruhi hasil panen dengan nilai signifikansi &gt; 0,000 dengan sub variabel lahan tadah hujan menyebabkan kerugian, biaya yang dibutuhkan untuk mengairi tanaman tembakau cukup besar, perlu dilakukan pencegahan mengantisipasi lahan tadah hujan, pengaturan pola tanam Petani tembakau perlu melakukan tumpang sari, petani tembakau perlu menggunakan sistem tumpang sari dan manfaat tampungan air (robek) bagi petani tembakau. Dalam hal ini, jika luas lahan garapan meningkat dan pendapatan meningkat, maka lahan tadah hujan dan pengelolaan strategis akan berkurang 1 satuan. Dan alangkah baiknya jika areal budidaya tetap dan pendapatan tetap, lahan tadah hujan dan pengelolaan strategis tetap

Characterization of Changes in Hyaluronan Following Epidermal Barrier Injury in an Organotypic Model

The stratum corneum, the outermost layer of the epidermis of skin, provides a functional permeability barrier that is essential for our survival and must be rapidly repaired after injury. Of interest to us, a ubiquitous matrix molecule called hyaluronan (HA) has come to the forefront in wound healing research because it is induced after epidermal injury and may be crucial for barrier repair. This thesis examines the role of HA during recovery from the most fundamental form of skin injury, i.e. selective damage to the stratum corneum. The overall question is whether this form of stratum corneum injury can lead to changes in HA similar to that of a full thickness skin wound. To investigate this question, a bioengineered model of barrier injury in organotypic epidermal cultures was first characterized. Changes in HA, in terms of an increase in overall amount and molecular weight, and increased levels of the HA-metabolizing enzymes (HA Synthases 2 and 3) were then measured and defined. Finally, the signalling mechanisms responsible for induction of HA synthesis were explored, revealing that activation of the Epidermal Growth Factor Receptor is essential for the up-regulation of HA after barrier injur

Characterization of Changes in Hyaluronan Following Epidermal Barrier Injury in an Organotypic Model

The stratum corneum, the outermost layer of the epidermis of skin, provides a functional permeability barrier that is essential for our survival and must be rapidly repaired after injury. Of interest to us, a ubiquitous matrix molecule called hyaluronan (HA) has come to the forefront in wound healing research because it is induced after epidermal injury and may be crucial for barrier repair. This thesis examines the role of HA during recovery from the most fundamental form of skin injury, i.e. selective damage to the stratum corneum. The overall question is whether this form of stratum corneum injury can lead to changes in HA similar to that of a full thickness skin wound. To investigate this question, a bioengineered model of barrier injury in organotypic epidermal cultures was first characterized. Changes in HA, in terms of an increase in overall amount and molecular weight, and increased levels of the HA-metabolizing enzymes (HA Synthases 2 and 3) were then measured and defined. Finally, the signalling mechanisms responsible for induction of HA synthesis were explored, revealing that activation of the Epidermal Growth Factor Receptor is essential for the up-regulation of HA after barrier injur

PENGARUH MOTIVASI BERPRESTASI GURU TERHADAP KINERJA GURU SEKOLAH DASAR NEGERI DI KECAMATAN PRINGSURAT KABUPATEN TEMANGGUNG

Penelitian ini bertujuan untuk mengetahui: 1) Tingkat motivasi berprestasi guru Sekolah Dasar Negeri di kecamatan Pringsurat; 2) Tingkat kinerja guru Sekolah Dasar Negeri di kecamatan Pringsurat; 3) Pengaruh motivasi berprestasi guru terhadap kinerja guru Sekolah Dasar Negeri di kecamatan Pringsurat. Metode penelitian dengan menggunakan pendekatan kuantitatif. Populasi dalam penelitian ini adalah seluruh guru Sekolah Dasar Negeri di kecamatan pringsurat dengan jumlah 203 guru. Jumlah sampel diambil berdasarkan table Kerjlie dan Morgan sebanyak 132 guru. Pengambilan sampel secara disproportionate stratified random sampling. Teknik pengumpulan data menggunakan angket. Uji asumsi yang dilakukan adalah uji normalitas, linieritas, nonkolinieritas, dan homosedastisitas. Uji Hipotesis menggunakan analisis regresi sederhana Hasil penelitian ini menyimpulkan bahwa: 1) Tingkat motivasi berprestasi guru Sekolah Dasar Negeri di kecamatan Pringsurat sebesar 77% dalam kategori sedang; 2) Tingkat kinerja guru di Sekolah Dasar Negeri di kecamatan Pringsurat sebesar 85% dalam kategori tinggi; 3) Motivasi berprestasi guru berpengaruh positif dan signifikan terhadap kinerja guru Sekolah Dasar Negeri di kecamatan Pringsurat ditunjukkan dengan koefisien korelasi sebesar 0,24, koefisien determinasi 0,06, F hitung sebesar 8,47, sumbangan efektifnya sebesar 6%. Kata-kata kunci: Motivasi Berprestasi Guru, Kinerja Guru