Зависимость физико-химических свойств ВТСП-соединений от размера кристаллитов

Керамическим методом с предварительным получением прекурсора синтезированы материалы состава Bi2Sr2Ca1−xLnxCu2Oу (Ln – La, Nd, Y, Ho, Lu) и Bi2Sr2−xLnxCaCu2Oу (Ln – La, Nd, Ho, Lu). Исследованы микроструктура, область гомогенности, электрофизические характеристики, кислородная стехиометрия систем Bi2Sr2Ca1−xLnxCu2Oу (Ln – La, Nd, Y, Ho, Lu) и Bi2Sr2−xLnxCaCu2Oу (Ln – La, Nd, Ho, Lu) в зависимости от степени замещения х и температуры перехода в сверхпроводящее состояние Тсon. Изучено влияние условий термической обработки на размеры кристаллитов, величину кислородного индекса и критическую температуру. Получены наноразмерные частицы (Dср = 0,5—1,5 мкм). Показано, что границы области гомогенности уменьшаются от 0 ≤ x ≤ 0,3 по Lu3+ к 0 ≤ x ≤ 0,05 по La3+.Керамічною методою з попереднім одержанням прекурсору синтезовано матеріяли складу Bi2Sr2Ca1−xLnxCu2Oу (Ln – La, Nd, Y, Ho, Lu) та Bi2Sr2−xLnxCaCu2Oу (Ln – La, Nd, Ho, Lu). Досліджено мікроструктуру, область гомогенности, електрофізичні характеристики й кисневу стехіометрію систем Bi2Sr2Ca1−xLnxCu2Oу (Ln – La, Nd, Y, Ho, Lu) і Bi2Sr2−xLnxCaCu2Oу (Ln – La, Nd, Ho, Lu) залежно від ступеня заміщення х та температури переходу в надпровідний стан Тсon. Вивчено вплив умов термічного оброблення на розмір зерна, величину кисневого індексу та критичну температуру. Одержано нанорозмірні частинки (Dсер = 0,5—0,15 мкм). Показано, що межі гомогенности зменшуються від 0 ≤ x ≤ 0,3 за Lu3+ до 0 ≤ x ≤ 0,05 за La3+.The samples of Bi2Sr2Ca1−xLnxCu2Oу (Ln–La, Nd, Y, Ho, Lu) and Bi2Sr2−xLnxCaCu2Oу (Ln–La, Nd, Ho, Lu) are synthesized using the ceramic technique with precursor. For Bi2Sr2Ca1−xLnxCu2Oy (Ln–La, Nd, Y, Ho, Lu) and Bi2Sr2−xLnxCaCu2Oу (Ln–La, Nd, Ho, Lu) systems, the dependences of microstructure, homogeneity region, electrophysical properties, and oxygen nonstoichiometry on their composition (x) and Tcon value are studied. Influence of heat-treatment conditions on the sizes of crystallites, value of oxygen index, and critical temperature is studied. As shown, the homogeneity region becomes narrower when going from 0 ≤ x ≤ 0.3 for Lu3+ to 0 ≤ x ≤ 0.05 for La3+

Analisa Numerik Efek Ketebalan Bluff Rectangular Terhadap Karakteristik Aliran Di Dekat Dinding

Bluff rectangular is one of turbulator which has function as flow disturbance. |The disturbance will be usefull and it becomes the trigger to accelerate flow transition from laminar and turbulent flow. However the disturbance could destroy the flow. It depends on the thickness of bluff rectangular. This research focused on the effect caused by the thickness of bluff rectangular toward the surrounding flow. The thickness variant which will investigate is 0.025d/Lu,0.0375d/Lu , 0.05d/Lu ,0.075d/Lu and 0.1d/Lu. This research utilize numerical analyze only when using Computation Fluid Dynamic method. In the simulation with free stream flow Red =103 based on bluff rectangular body thickness (d) on steady state condition and turbulent viscous model used Shear Stress Transport k-Omega. Numerical result shown that bubble separation flow will not occur by using bluff rectangular with 0.025d/Lu ,where it is not as for other thinckness. Especially for bluff rectangular by 0.0375d/Lu occur delayed bubble separation which lie x=1.5d after bluff rectangular point, whereas for 0.05d/Lu ,0.075d/Lu and 0.1d/Lu bubble separation lie right behind bluff rectangular. For bubble separation which occured is inversely linear with the bluff rectangular thickness. velocity profile occured on x=4Lu shown should 0.075d/Lu and 0.1d/Lu bluff rectangular has higher velocity near the wall especially y/δ < 0.1. The smallest shape factor produced by 0.075d/Lu bluff rectangular hence it is stated as the best turbulator

Penampilan Karakter Produksi Kacang Panjang (Vigna Sinensis L.) Generasi F1 dan Tetuanya

Kacang panjang sering dikonsumsi masyarakat sehingga permintaan ketersediaanya sangat tinggi, USAha yang dilakukan untuk meningkatkan produksi kacang panjang adalah dengan memperoleh varietas yang memiliki sifat unggul dengan produksi tinggi.Penelitian ini bertujuan untuk membandingkan karakter produksi hasil persilangan Hitam x Lurik dan Lurik x Hitam dengan tetuanya dan produksi hasil persilangan resiprok yaitu Hitam x Lurik dengan Lurik x Hitam. Benih yang digunakan adalah benih Hitam, Lurik, Hitam x Lurik dan Lurik Hitam.Perlakuan disusun dalam Rancangan Acak Lengkap (RAL) dan data diuji dengan uji LSI dan heterosis.Hasil penelitian dengan uji LSI menunjukkan bahwa pada karakter produksi hanya panjang polong zuriat Lu x Hi yang lebih baik dari kedua tetuanya. Nilai duga heterosis menunjukkan bahwa karakter produksi zuriat Hi x Lu yang memiliki efek heterosis dan heterobeltiosis yaitu pada karakter jumlah dan bobot polong sedangkan pada zuriat Lu x Hi hanya karakter panjang polong yang mengalami efek heterosis dan heterobeltiosis

GRB 060206: Evidence of Precession of Central Engine

The high-redshift (z = 4.048) gamma-ray burst GRB 060206 showed unusual behavior, with a significant re-brightening about 3000 s after the burst. We assume that the central engine became active again 2000 s after the main burst and drove another more collimated off-axis jet. The two jets both interacted with the ambient medium and contributed to the whole emission. We numerically fit this optical afterglow from the two jets using the forward-shock model and the forward-reverse shock model. Combining with the zero time effect, we suggest that the fast rise at ~3000 s in the afterglow was due to the off-axis emission from the second jet. The precession of the torus or accretion disk of the gamma ray burst engine is the natural explanation for the symmetry axes of these two jets not to lie on the same line

Liberty’s Honors Manager, Mrs. Laura Kline: Service to Lord and Family

Meet the Manager of LU Honors\u27 Program, Mrs. Laura Kline