211,258 research outputs found
Direct numerical simulation of 'short' laminar separation bubbles with turbulent reattachment
No full textDirect numerical simulation of the incompressible Navier–Stokes equations is used to study flows where laminar boundary-layer separation is followed by turbulent reattachment forming a closed region known as a laminar separation bubble. In the simulations a laminar boundary layer is forced to separate by the action of a suction profile applied as the upper boundary condition. The separated shear layer undergoes transition via oblique modes and [Lambda]-vortex-induced breakdown and reattaches as turbulent flow, slowly recovering to an equilibrium turbulent boundary layer. Compared with classical experiments the computed bubbles may be classified as ‘short’, as the external potential flow is only affected in the immediate vicinity of the bubble. Near reattachment budgets of turbulence kinetic energy are dominated by turbulence events away from the wall. Characteristics of near-wall turbulence only develop several bubble lengths downstream of reattachment. Comparisons are made with two-dimensional simulations which fail to capture many of the detailed features of the full three-dimensional simulations. Stability characteristics of mean flow profiles are computed in the separated flow region for a family of velocity profiles generated using simulation data. Absolute instability is shown to require reverse flows of the order of 15–20%. The three-dimensional bubbles with turbulent reattachment have maximum reverse flows of less than 8% and it is concluded that for these bubbles the basic instability is convective in nature
ANALISA KADAR LOGAM TIMBAL (Pb) PADA BEBERAPA MADU ALAM
No full textTelah dilakukan analisa kadar logam timbal (Pb) pada beberapa madu alam, Madu yaitu madu yang berasal dari Kebun Raya Samarinda (KRUS), madu Sulawesi dan madu yang berasal dari budidaya di Fakultas Matematika dan Ilmu Pengetahuan Universitas Mulawarman. Preparasi sampel didestruksi basah dengan wet digester menggunakan kombinasi HNO3(P) - H2O2(P). Hasil penelitian menunjukan adanya kadar logam berat timbal (Pb) pada madu alam ; untuk sampel A (Kebun Raya Universitas Mulawarman Samarinda) sebesar 0.0767 mg/kg, untuk sampel B (Fakultas Matematika dan Ilmu Pengetahuan Universitas Mulawarman Samarinda) sebesar 1.0867 mg/kg dan sampel C (madu alam Sulawesi) sebesar 1.6667 mg/kg. Dengan demikian, madu alam tersebut masih dalam ambang batas diperbolehkannya kandungan Pb dalam makanan yang ditetapkan oleh BSN. 2009. SNI 7387: 2009 yakni sebesar 2,0 mg/kg. Dari hasil proses analisis Pb pada madu tidak memerlukan penambahan standar adisi pada metode pendekteksiannya.
Kata kunci : Lebah tanpa sengat (Trigona Spp), Timbal (Pb), Madu, Destruksi Basah
Smartphone Controlled Robo Car(Via Bluetooth)
No full text<p>Team Name-RoboFever.</p><p>Authors: Md Iftekharul Alam, Minhazul Abedin, Nur Mohammad Al Kawsar</p><p>Project Name-Smartphone Controlled Robo Car(Via Bluetooth).</p>
Pump it up - Developing a pro-poor mobile pump market
No full textBadrul Alam, Noel P. Magor And Paul Van Mel
SISTEM PENGENDALIAN INTERNAL KAS PADA BAGIAN ADMINISTRASI KEUANGAN DI SEKOLAH ALAM INSAN MULIA SURABAYA
No full textThis study aims to determine the system of internal control of cash in the financial administration in the School of Nature Insan Mulia Surabaya, private schools under the auspices of Insan Mulia Foundation engaged in education services. This research uses descriptive qualitative research method, by collecting, describing, analyzing and explaining data about internal control
system of cash receipts and expenditure on financial administration function of Sekolah Alam Insan Mulia. The type of data used is primary data and secondary data. The result of the research can be concluded that the application of internal control system of cash receipts and expenditure on the financial administration function of Sekolah Alam Insan Mulia is good, however there are still some aspects that need to be improved that is: need additional internal audit function, one cashier perform accounting and cash functions should Insured
Recommendation domains for pond aquaculture: country case study: development and status of freshwater aquaculture in Bangladesh
No full textThis report is an output of the project ôDetermination of high-potential aquaculture development areas and impact in Africa and Asiaö. This monograph is the case study for Bangladesh. Written in three parts, it describes the historical background, practices, stakeholder profiles, production levels, economic and institutional environment, policy issues, and prospects for aquaculture in the country. First, it documents the history and current status of the aquaculture in the country. Second, it assesses the technologies and approaches that either succeeded or failed to foster aquaculture development and discusses why. Third, it identifies the key reasons for aquaculture adoption.Freshwater aquaculture, Economic analysis, Trade, Ecosystems, Pond culture, Fish consumption, Food security, Policies, Regulations, Legislation, Socioeconomic aspects, Yield, Bangladesh,
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Upacara tradisional yang berkaitan dengan peristiwa alam dan kepercayaan daerah Sumatera Barat
No full textRuang lingkup kegiatan inventarisasinya dibatasi pada upacara tradisional yang berkaitan dengan peristiwa alam dan kepercayaan di Sumatera Barat. Di kalangan para petani penyelenggaraan upacara biasanya dikaitkan dengan masalah kesuburan. Diharapkan setelah mengadakan upacara hasil panennya akan berlimpah. Demikian pula di kalangan para nelayan penyelenggaraan upacara bertujuan untuk memperoleh basil laut sebanyak mungkin. Di samping itu ada pula dilakukan upacara untuk menolak berbagai wabah penyakit, dan bencana lainnya seperti gangguan binatang buas. Pada umumnya mereka mengenal kepercayaan pada kekuatan gaib di luar kekuasaan manusia yang bersifat supra natural yang dapat menentukan nasib manusia, dapat menimbulkan malapetaka tapi juga dapat menjamin kesejahteraa.n hidup manusia.
Selain upacara yang berkaitan dengan kesuburan tanah, hasil
laut dan menolak segala macam bencana, ada pula yang berkaitan dengan peristiwa alam lainnya, misalnya berkenaan dengan terjadinya kemarau panjang atau turunnya curah hujan berkepanjangan yang mengakibatkan terjadinya banjir. Dalam kepercayaan masyarakat tradisional malapetaka yang timbul dari alam itu bisa diredakan dengan menyelenggarakan upacara. Roh-roh penguasa alam itu dalam kepercayaan masyarakat bisa dibujuk dengan saji-sajian yang dihidangkan dalam upacara, dan dimohon agar tidak membuat bencana dan sebaliknya mau menjaga keselamatan umat manusia.
Penyelenggaraan upacara itu perlu dideskripsikan sejak persiapannya sampai selesai. Selain itu perlu juga dicatat hal-hal yang berkaitan dengan upacara tersebut, misalnya penggunaan simbol-simbol dan maknanya menurut interprestasi pendukung upacara. Juga perlu dicatat pantangan dan berbagai persyaratan yang harus dipatuhi dan dipenuhi oleh penyelenggara menurut tradisi setempat
Ultra-broadband wavelength conversion based on four-wave mixing in a Raman DFB fiber laser
No full textWe report highly efficient four-wave mixing (FWM) within a 30cm-long centre pi phase-shifted Raman DFB fiber laser with a continuous frequency tuning range of ~19.9 THz with the FWM conversion efficiency up to -25dB
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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