Multi-phase-field analysis of short-range forces between diffuse interfaces

We characterize both analytically and numerically short-range forces between spatially diffuse interfaces in multi-phase-field models of polycrystalline materials. During late-stage solidification, crystal-melt interfaces may attract or repel each other depending on the degree of misorientation between impinging grains, temperature, composition, and stress. To characterize this interaction, we map the multi-phase-field equations for stationary interfaces to a multi-dimensional classical mechanical scattering problem. From the solution of this problem, we derive asymptotic forms for short-range forces between interfaces for distances larger than the interface thickness. The results show that forces are always attractive for traditional models where each phase-field represents the phase fraction of a given grain. Those predictions are validated by numerical computations of forces for all distances. Based on insights from the scattering problem, we propose a new multi-phase-field formulation that can describe both attractive and repulsive forces in real systems. This model is then used to investigate the influence of solute addition and a uniaxial stress perpendicular to the interface. Solute addition leads to bistability of different interfacial equilibrium states, with the temperature range of bistability increasing with strength of partitioning. Stress in turn, is shown to be equivalent to a temperature change through a standard Clausius-Clapeyron relation. The implications of those results for understanding grain boundary premelting are discussed.Comment: 24 pages, 28 figure

Afro-Caribbean Immigrant Faculty Experiences in the American Academy: Voices of an Invisible Black Population

Afro-Caribbean immigrants have been an integral part of the history and shaping of the United States since the early 1900s. This current study explores the experiences of five Afro-Caribbean faculty members at traditionally White institutions of higher education. Despite the historical presence and influence of Afro-Caribbean communities and the efforts within education systems to address the needs of Afro-Caribbean constituents, Afro-Caribbean faculty members continue to be rendered indiscernible in higher education and to be frequently and erroneously perceived as African–Americans. The study examines the lived experiences of these individuals in the hegemonic White spaces they occupy at their institutions with both White and Black populations. Through their narratives, issues of stereotyping, microaggression, and isolation are addressed. The participants also offer solutions to address these issues by university administrators, department heads, faculty development professionals, diversity officers, policy makers, and other stakeholders. The voices in this study shed light on an overlooked, misunderstood, and under-researched population within our faculty ranks in the American Academy

Dynamics of open quantum systems initially entangled with environment: Beyond the Kraus representation

We present a general analysis of the role of initial correlations between the open system and an environment on quantum dynamics of the open system.Comment: 5 revtex pages, no figures, accepted for publication in Phys. Rev.

Relativistic quantum plasma dispersion functions

Relativistic quantum plasma dispersion functions are defined and the longitudinal and transverse response functions for an electron (plus positron) gas are written in terms of them. The dispersion is separated into Landau-damping, pair-creation and dissipationless regimes. Explicit forms are given for the RQPDFs in the cases of a completely degenerate distribution and a nondegenerate thermal (J\"uttner) distribution. Particular emphasis is placed on the relation between dissipation and dispersion, with the dissipation treated in terms of the imaginary parts of RQPDFs. Comparing the dissipation calculated in this way with the existing treatments leads to the identification of errors in the literature, which we correct. We also comment on a controversy as to whether the dispersion curves in a superdense plasma pass through the region where pair creation is allowed.Comment: 16 pages, 1 figur

Pengaruh Literasi Keuangan Dan Persyaratan Kredit Terhadap Akses Kredit Formal Pada UMKM Di Surabaya

Peningkatan Usaha Mikro Kecil Menengah (UMKM) di Indonesia yang begitu pesat mampu mendorong pertumbuhan ekonomi. Adanya kebijakan pemerintah tentang pembiayaan UMKM memotivasi UMKM agar mampu menciptakan sistem pembiayaan yang baik sehingga mempengaruhi kemudahan mengakses kredit. Pada studi literatur disebutkan bahwa mengakses kredit formal merupakan hal penting karena lembaga penyedia kredit formal lebih memiliki ketersediaan dana daripada lembaga penyedia kredit informal. Di beberapa negara berkembang, UMKM mengakses kredit informal karena persyaratan kreditnya lebih mudah daripada persyaratan kredit di lembaga penyedia kredit formal. Akses kredit yang dilakukan pada USAha kecil juga didasari oleh perilaku perbankan dimana perilaku perbankan pemilik UMKM dipengaruhi oleh literasi keuangan. Upaya yang dilakukan Dinas Koperasi dan UMKM dalam meningkatkan literasi keuangan adalah memberikan pelatihan keuangan yang dianalisis efektivitasnya dalam penelitian. Penelitian ini bertujuan untuk mengetahui pengaruh literasi keuangan dan persyaratan kredit terhadap akses kredit formal serta mengetahui efektivitas pelatihan keuangan yang didapatkan oleh UMKM. Metode dalam penelitian ini adalah regresi linear berganda dan independent sample t test. Sampel penelitian berjumlah 80 responden yang pernah mengakses kredit formal. Simpulan dari penelitian yakni literasi keuangan dan persyaratan kredit berpengaruh positif signifikan terhadap akses kredit formal serta tidak terdapat perbedaan antara kelompok sampel yang pernah dan belum pernah mendapatkan pelatihan keuangan

Implementasi Algoritma Boyer Moore pada Web E-katalog Flora dan Fauna Pulau Jawa Sumatera

Indonesia memiliki kekayaan flora dan fauna serta kehidupan liar lainnya yang mengundang perhatian dan kekaguman berbagai pihak baik di dalam maupun di luar negeri. Tercatat tidak kurang dari 515 spesies mamalia (terbanyak di dunia), 1.519 spesies burung (keempat terbanyak), 270 spesies amfibia (kelima terbanyak), 600 spesies reptilian (ketiga terbanyak), 121 spesies kupu-kupu (terbanyak) dan 20.000 spesies tumbuhan berbunga (ketujuh terbanyak) menghuni habitat-habitat daratan dan lautan di 112 kepulauan, Memiliki 17.058 pulau dan setiap pulau memiliki keanekaragaman flora dan fauna yang tinggi, termasuk tingkat endemis dan keanekaragamannya. Aplikasi pengarsipan (katalog) menggunakan metode Boyer Moore untuk proses pencarian data, algoritma ini memiliki tingkat keakuratan dalam pencocokan string (text) dan pembacaan setiap karakter dari pattern kanan ke kiri. Penelitian ini berupa aplikasi berbasis web yaitu e-katalog yang mengumpulkan informasi flora dan fauna endemik Indonesia, aplikasi memberikan informasi secara akurat berdasarkan wilayah atau propinsi, e-katalog dilengkapi pencarian yang akurat dengan menggunakan algoritma Boyer Moore. Implementasi algoritma Boyer Moore pada e-katalog memberikan kemudahan dalam mencari informasi yang berhubungan dengan flora dan fauna endemik Indonesia secara akurat dan efisien, e-katalog memberikan informasi berdasarkan kategori setiap perwilayah atau propinsi secara akurat