Directional solidification of Pb-Sn eutectics with vibration

Pb-Sn eutectic alloy was directionally solidified at 1.4 to 3.2 cm/hr with forced convection induced by axial vibration of the growth ampoule with a frequency of 10 to 40 Hz and an amplitude of 0.5 to 1.0 mm. To determine the exact growth rate, an interface demarcation technique was applied. The lamellar spacing was increased 10 to 40 percent in ingots solidified with vibration compared to those solidified without vibration. The number of grain boundaries was increased by vibration. The average intensity of convection in the melt under axial vibration of the ampoule was estimated by comparing the experimental results with a theoretical model

Directional solidification of Pb-Sn eutectic with vibration

Pb-Sn eutectic alloy was directionally solidified at 1.4 to 3.2 cm/hr with forced convection induced by axial vibration of the growth ampoule with a frequency of 10 to 40 Hz and an amplitude of 0.5 to 1.0 mm. To determine the exact growth rate, an interface demarcation technique was applied. The lamellar spacing was increased 10 to 40 percent in ingots solidified with vibration compared to those solidified without vibration. The average intensity of convection in the melt under axial vibration of the ampoule was estimated by comparing the experimental results with a theoretical model

A novel approach to determine the heat transfer coefficient in directional solidification furnaces

The heat transfer coefficient between a molten charge and its surroundings in a Bridgman furnace was determined using an approach utilizing in-situ temperature measurement. The ampoule containing an isothermal melt was suddenly moved from a higher temperature zone to a lower temperature zone. The temperature-time history was used in a lumped-capacity cooling model to evaluate the heat transfer coefficient between the charge and the furnace. The experimentally determined heat transfer coefficient was of the same order of magnitude as the value estimated by standard heat transfer calculations

PERBEDAAN MINAT SISWA SMK NEGERI 13 DAN SMK FARMASI BUMI SILIWANGI KOTA BANDUNG DALAM MATA PELAJARAN PENDIDIKAN JASMANI OLAHRAGA DAN KESEHATAN

Tujuan penelitian ini untuk mengetahui apakah ada perbedaan minat siswa antara SMK Negeri 13 Bandung dan SMK Farmasi Bumi Siliwangi Bandung dalam mata pelajaran pendidikan jasmani olahraga dan kesehatan. Dalam penelitian ini penulis menggunakan desain penelitian deskriptif yang dimaksudkan untuk memberikan gambaran mengenai perbedaan variabel-variabel penelitian yang dimaksud. Populasi dalam penelitian ini adalah Siswa SMK Negeri 13 dan siswa SMK Farmasi Bumi Siliwangi. Hasil dari penelitian ini menggunakan perhitungan pengujian hipotesis uji t dan hasil yang diperoleh terdapat perbedaan signifikan antara minat siswa SMK Negeri 13 dan SMK Farmasi Bumi Siliwangi kota Bandung dalam mata pelajaran Pendidikan Jasmani Olahraga dan Kesehatan. Sedangkan untuk nilai perbedaan terlihat dari rata-rata hasil angket SMK Farmasi Bumi Siliwangi sedikit lebih tinggi yaitu 4,221546 dibanding SMK Negeri 13 yaitu 4,090443.---------- The purpose of this research is to know something different about student interest between SMK Negeri 13 Bandung and SMK Farmasi Bumi Siliwangi Bandung on physical education, sport and health. In this research the writer uses descriptive research design to giving description about a different research variables. The population on this research is students of the SMK Negeri 13 and SMK Farmasi Bumi Siliwangi. The result of this research is using hypothesis counting test (t test) and the obtainable results have a significant different between student interest of SMK Negeri 13 and SMK Farmasi Bumi Siliwangi on physical education, sport and health. Whereas a value different can be see from average result quesioner SMK Farmasi Bumi Siliwangi is a bit higher, it’s about 4,221546 then SMK Negeri 13 who get score about 4,090443

An experimental approach to determine the heat transfer coefficient in directional solidification furnaces

The heat transfer coefficient between a molten charge and its surroundings in a Bridgman furnace was experimentally determined using in-situ temperature measurement. The ampoule containing an isothermal melt was suddenly moved from a higher temperature zone to a lower temperature zone. The temperature-time history was used in a lumped-capacity cooling model to evaluate the heat transfer coefficient between the charge and the furnace. The experimentally determined heat transfer coefficient was of the same order of magnitude as the theoretical value estimated by standard heat transfer calculations

Islamisasi Ilmu Pengetahuan Perspektif Ismail al Faruqi

Tulisan ini bertujuan untuk mengkaji bagaimana sebenarnya upaya Islamisasi ilmu pengetahuan dan implikasinya tehadap pendidikan Islam, serta untuk membuktikan bahwa gagasan Islamisasi ilmu merupakan salah satu fenomena gerakan pemikiran kontemporer aktivis dunia Islam di Era 1970-an hingga awal 1980-an. Secara operasional penelitian ini menerapkan metode analisis data. Penggunaan analisis data deskriptif metode yang dimaksudkan untuk menganalisis pemikiran dan gagasan Islamisasi ilmu pengetahuan dan implikasinya bagi fondasi pendidikan Islam. Sumber utama yang dirujuk dalam penelitian ini merupakan karya pemikiran Ismail al-Faruqi terkait dengan konsep Islamisasi ilmu dengan pemikir muslim lainnya seperti Syed Muhammad Naquib Al Attas sebagaimana diketahui bahwa sejak gencarnya wacana Islamisasi ilmu, mengundang para ahli untuk berdiskusi. Di antara para cendekiawan Muslim telah mengemukakan pentingnya sains untuk percaya bahwa sains diperlukan untuk mengislamkan, mengingat sains dalam Pandangannya telah meracuni ideologi dan nilai-nilai filsafat Barat yang banyak bertentangan dengan ajaran Islam. Al-Faruqi dan Al-Attas muncul di tengah-tengah mereka sebagai dua tokoh sentral yang gigih dan kritis mencurahkan gagasannya dalam ilmu pengetahuan modern program islamisasi. Dalam benak mereka, realitas pendidikan yang berkembang saat ini menganut dua sistem pendidikan, yaitu sistem pendidikan Islam dan sistem pendidikan sekuler. Sistem pendidikan, dalam rangka islamisasi ilmu keduanya sistem pendidikan harus diintegrasikan ke dalam sistem yang holistik sehingga tercipta pendidikan sistem yang kuat baik secara material maupun spiritual. Kata kunci: Islamisasi, Sains, Pendidikan Isla

Who am I without exile? Syrian everyday life in Cairo

This thesis examines the fluidity and complexity of the everyday lives of Syrians in Egypt. While it is not meant to be comprehensive, and speaks to the very particular social in which the research was conducted, this project seeks to disrupt the processes with which categorizations and solid understandings of migration and refugeeness emerge. It argues that neat understandings of the everyday is not possible, but rather, a closer reading uncovers the undoing and reassembling of the intricate relations at play- processes that speak to the very core understandings of power, governance, and sovereignty. By methodologically employing the idea of the mess, the fragmented way in which the self navigates a contradictory everyday life becomes visible: a process that is rife with myriad encounters with various forms of powers. The thesis grapples with everyday mundane events, and not so mundane events, to trace the paths which the self configures, be it through the moment of arrival, bureaucratic navigation, modes of survival, community imagination, or the potentialities of reconfiguration. This thesis attempts to push away from the rhetoric of brush-stroking experiences assumed to be interchangeable, like “Syrian†and “refugeeâ€, and concludes instead with a note on embracing the world that is in flux

Fabrication of novel poly (vinylidene fluoride) /MWCNT nanocomposite ultrafiltration membranes for natural organic matter removal

Poly (vinylidene) fluoride (PVDF) has advantages as a membrane material compared to other commercialized polymeric materials as it is easily dissolved in common organic solvents and its proper asymmetric structure for separation. However, its hydrophobic characteristics lead to low water flux and makes PVDF membrane easily fouled while treating solutions containing natural organic matters. The aim of this research is to enhance the performance of PVDF ultrafiltration membrane by using different additives. In the first part (MWCNT)/ polydopamine (PDA) was used as additives with different MWCNT concentrations. The PVDF membrane blended with a mixture of 2% dopamine/ 1% MWCNT showed 20 folds improvements in permeability in comparison to pristine PVDF ultrafiltration membrane. Furthermore, it demonstrated about 81% rejection for Suwannee River Humic acid (HA) filtration test. In the second part, (PANI) was used as an additive. Two blending methods of aniline were applied, and the synthesized PANI was used as an additive to produce PANI/PVDF modified membranes. Results show that the water permeability and antifouling properties of modified PVDF membranes were both improved. Water permeability of PANI/PVDF modified membranes were 7-16 times greater than pristine PVDF. Finally, MWCNT/PANI/ PVDF ultrafiltration membrane was prepared by phase inversion technique. The resultant membrane of (PANI/ 1.5 % MWCNT) showed the highest permeability results (1320 LMH/bar) among membranes we tested with 40 folds permeability improvement in comparison to pristine PVDF ultrafiltration membrane. Furthermore, it showed about 79% rejection HA filtration test

The Journey Narrative: The Trope of Women\u27s Mobility and Travel in Contemporary Arab Women\u27s Literary Narratives

This study examines the trope of women\u27s journey and the various kinds of movement and travel it includes employed and represented by three contemporary Arab women literary writers, Ghada Samman, Ahdaf Soueif, and Leila Aboulela in their literary narratives as well as travelogue in the case of Samman. The primary texts analyzed in this study are Samman\u27s Beirut 75 and The Body Is a Traveling Suitcase, Soueif\u27s In the Eye of the Sun, and Aboulela\u27s The Translator and Minaret. These texts demonstrate how the journey trope becomes a fresh narrative strategy used by Arab women writers that allows the representation of the instability, unpredictability, and heterogeneity of Arab women\u27s identities. The multiple subjectivities the female persona/protagonists occupy become possible due to their mobility and movement, crossing the borders of time and space and occupying a fluid place of their own theoretical and imaginative construction. In these texts, travel creates a geographic in-between space for these women that allows them to contest essentialized views of their identities and narrate their own individual, hybrid, cross-cultural, and transnational identities that continually undergo transformation and change. I argue that the mobility, travel experiences, journeys, and physical displacement the persona/protagonists go through serve as tropes of female agency: movement allows them to map personal geographies and exist in a liminal space of their own construction, where they counter fixed Western Orientalist, Neo-Orientalist, and traditional patriarchal discourses that presented them at different historical moments as speechless, subaltern, and stripped of their agency. As a result, the journey trope serves both as a way to examining the varied representations of Arab woman subjectivities in addition to destabilizing fixed notions of gendered, cultural, and religious identity formations

Results of compositional and microstructural analyses of solidified ingots

The results of compositional and microstructural analysis of solidified ingots are discussed. In the vibration section, the microstructural and compositional analysis of ingots solidified with and without vibration, the vibration induced dynamic acceleration measurements, and the macroscopic growth rate measurements using an interface demarcation technique are discussed. The Current induced Perturbation section includes the results of solidification of an ingot with alternating current pulses, the current interface demarcation in an alloy of In0.2Ga0.8SB, and in situ temperature measurements in the charges of GaSb and In0.2Ga0.8Sb during the passage of electric current