Dispersion of biased swimming microorganisms in a fluid flowing through a tube

Classical Taylor-Aris dispersion theory is extended to describe the transport of suspensions of self-propelled dipolar cells in a tubular flow. General expressions for the mean drift and effective diffusivity are determined exactly in terms of axial moments, and compared with an approximation a la Taylor. As in the Taylor-Aris case, the skewness of a finite distribution of biased swimming cells vanishes at long times. The general expressions can be applied to particular models of swimming microorganisms, and thus be used to predict swimming drift and diffusion in tubular bioreactors, and to elucidate competing unbounded swimming drift and diffusion descriptions. Here, specific examples are presented for gyrotactic swimming algae.Comment: 20 pages, 4 figures. Published version available at http://rspa.royalsocietypublishing.org/content/early/2010/02/09/rspa.2009.0606.short?rss=

Analisa Pengaruh Trim Terhadap Konsumsi Bahan Bakar

Trim merupakan salah satu kondisi pada kapal dimana terdapat perbedaan draft pada bagian haluan dan buritan. Kapal bergerak dengan kecepatan dinasnya (Vs) pada kondisi normal continuous rating.Pada tahap pendesainan kapal tahanan total kapal (Rt) didapatkan pada kondisi kapal even keel. Namun pada pengoperasianya kapal jarang berada pada kondisi even keel tapi berada pada kondisi trim, baik trim by stern ataupun trim by bow. Penelitian ini ditujukan untuk mendapatkan tahanan total yang minimum dengan variasi trim yang dibuat pada kondisi displasemen 100%, 95%, 90%, 75% dan 55%. Dan juga berapa konsumsi bahan bakar yang dibutuhkan. Untuk dapat melakukan penelitian ini diperlukan pembuatan trim diagram untuk mengetahui variasi trim yang menghasilkan displasemen yang sama. Dan juga dibutuhkan software MAXSURF 11.12 untuk menganalisa tahanan dari variasi trim yang dibuat. Dari hasil penelitian diperoleh bahwa variasi trim yang menghasilkan tahanan total paling minimal adalah trim by stern, namun terdapat satu kondisi dimana tahan total yang paling minimum adalah trim by bow yaitu pada saat kondisi 100% displasemen. Hal ini dikarenakan pada kondisi tersebut area transom pada kapal ketika trim by stern banyak tercelup di dalam air, sedangkan ketika trim by bow hanya sedikit area transom yang tercelup di dalam air. Sehingga menyebabkan tambahan tahanan total pada saat trim by stern. Sedangkan untuk konsumsi bahan bakar yang dibutuhkan berbanding lurus dengan besarnya daya yang dibutuhkan

Analisis Perhitungan Unit Cost Sewa Kamar Kelas II Ar Rahman Dengan Metode Activity-based Costing (Studi Kasus Di RSU PKU Muhammadiyah Bantul)

Background: Determination of unit costs of inpatient room rental in PKU Muhammadiyah Hospital of Bantul is currently using traditional methods of real cost. When viewed in terms of space, design space and facilities for wards between class II class II Ar Rahman with other wards there is a difference. But the room rental unit cost of hospitalization between class II and class II Ar Rahman other similar effect.Methods: The study was conducted in PKU Muhammadiyah Hospital of Bantul. This type of research is a qualitative descriptive case study design. The sample in the study were nurses and managers supporting units taken purposively sampling. Cost analysis method used is the Activity-Based Costing (ABC).Results and Discussion: The unit cost of room rental class II Ar Rahman is calculated by the method of Activity-Based Costing (ABC) amounting to Rp. 77.540, -, while those issued by the hospital of Rp. 42 308, -. This indicates that the unit cost is calculated by Activity-Based Costing is greater than the unit cost hospitals. In Activity-Based Costing (ABC), indirect costs (overheads) charged to a cost driver while in the traditional system is only charged on a cost driver.Conclusions and Suggestions: Method of Activity-based Costing (ABC) can provide information regarding the calculation of more accurate cost, so it can be used by management to take accurate decisions in the budgeting and planning costs. The hospital should conduct an evaluation unit cost for rooms that are used so as not to harm the hospital or the patient

Taylor dispersion with absorbing boundaries: A Stochastic Approach

We describe how to solve the problem of Taylor dispersion in the presence of absorbing boundaries using an exact stochastic formulation. In addition to providing a clear stochastic picture of Taylor dispersion, our method leads to closed-form expressions for all the moments of the convective displacement of the dispersing particles in terms of the transverse diffusion eigenmodes. We also find that the cumulants grow asymptotically linearly with time, ensuring a Gaussian distribution in the long-time limit. As a demonstration of the technique, the first two longitudinal cumulants (yielding respectively the effective velocity and the Taylor diffusion constant) as well as the skewness (a measure of the deviation from normality) are calculated for fluid flow in the parallel plate geometry. We find that the effective velocity and the skewness (which is negative in this case) are enhanced while Taylor dispersion is suppressed due to absorption at the boundary.Comment: 4 pages, 1 figur

Perangkat Lunak Pengucapan Kata Bahasa Indonesia Berdasarkan Pemenggalan Kata Dengan Finite State Automata

Pada tugas akhir ini dikembangkan sebuah perangkat lunak yang berfungsi untuk mengetahui bagaimana pengucapan kata bahasa Indonesia. Pengucapan kata berdasarkan hasil pemenggalan kata dengan menggunakan Finite State Automata (FSA), yaitu suatu model dari mesin pengenal yang mampu mengenali kelas bahasa yang paling sederhana yaitu kelas bahasa Reguler. Pemenggalan kata berdasarkan bagaimana kata tersebut diucapakan. Teks bahasa Indonesia akan disajikan dalam bentuk suara atau ucapan. Pembacaan teks berdasarkan hasil pemenggalan kata. Suara yang disimpan adalah berupa rekaman dari tiap penggalan kata, sehingga akan lebih efisien karena setiap penggalan kata dapat digunakan dalam berbagai kata. Pembuatan perangkat lunak ini didahului dengan perancangan sistem aplikasi. Kemudian rancangan tersebut diimplementasikan. Implementasi aplikasi ini terdiri dari empat proses, yaitu proses pengisian array dari database, proses membersihkan teks, proses FSA dan proses pemenggalan kata. Setelah dimplementasikan, perangkat lunak ini diuji coba sesuai dengan spesifikasi kebutuhan dan kemampuan yang dimiliki yaitu melakukan pemenggalan kata bahasa Indonesia. Seperti memenggal kata dalam sebuah kalimat, kata homograf, diftong, kata berimbuhan dan kata serapan. Hasil pemenggalan kata disajikan dalam bentuk suara atau ucapan. Selain itu, aplikasi ini juga dapat memenggal angka yang sebelumnya dikonversi dulu menjadi kata yang kemudian angka akan dibaca satu per satu. Dengan demikian perangkat lunak ini dapat digunakan sebagaimana mestiny

Design Study: Integer Subtraction Operation Teaching Learning Using Multimedia in Primary School

This study aims to develop a learning trajectory to help students understand concept of subtraction of integers using multimedia in the fourth grade. This study is thematic integrative learning in Curriculum 2013 PMRI based. The method used is design research consists of three stages; preparing for the experiment, design experiment, retrospective analysis. The studied was conducted on 20 students of grade four SDN 1 Muara Batun, OKI. The activities of students in this study consisted of six learning trajectories. The first activity asks the students to classify heroism and non-heroism acts, summarize, and classify integers and non-integer. The second activity asks the students to answer the questions in the film given. The third activity asks students to count the remaining gravel in the film. The fourth activity asks students to count remaining spent money in the film. The fifth activity invites students to play rubber seeds in the bag. The last activity asks students to answer the questions in the student worksheet. The media used along the learning activities are a ruler, rubber seed, student worksheet, money, gravel, and film. The results indicate that the learning trajectory using multimedia help students understand the concept of integer subtraction integer

An Assessment of Risk of Iodine Deficiency Among Pregnant Women in Sarawak, Malaysia

Previous findings from a state-wide Iodine Deficiency Disorders (IDD) study among pregnant women (PW) in Sarawak indicated that PW are at risk of IDD and further assessment is needed. This paper describes the methodology used in conducting this study for an assessment of risk of iodine deficiency among pregnant women in Sarawak, Malaysia. A total of 30 maternal child health care clinics (MCHCs) were selected using probability proportional to population size (PPS) sampling technique. The PW sample size was calculated based on 95% confidence interval (CI), relative precision of 5%, design effect of 2, anticipated IDD prevalence of 65.0% and non-response rate of 20%. Thus, the total sample size required was 750 (25 respondents per selected MCHC). The WHO Expanded Programme on Immunization (EPI) surveys approach was used to randomly select the first respondent and subsequent respondents were chosen until the required number of PW was met. The required data were obtained through: face-to-face interviews (socio-demographic and food frequency questionnaire), clinical assessments (thyroid size, and hyper/hypothyroidism) and biochemical analysis (urine and blood serum). A total of 677 PW responded in the study with a response rate of 90.2%. Majority of the PW were at second gravida, aged 25-29 years old and of Malay ethnicity. The methodology used in this study was based on International guidelines which may provide state's estimates. All the necessary steps were taken into consideration to ensure valid and reliable findings on current iodine status among PW

Two-Channel Kondo Physics from Tunnelling Impurities with Triangular Symmetry

Tunnelling impurities in metals have been known for some time to have the potential for exhibiting Kondo-like physics. However previous models based on an impurity hopping between two equivalent positions have run into trouble due to the existence of relevant operators that drive the system away from the non-Fermi-liquid Kondo fixed point. In the case of an impurity hopping among positions with higher symmetry, such as triangular symmetry, it is shown here that the non-Fermi-liquid behavior at low temperatures can be generic. Using various bosonization techniques, the fixed point is shown to be {\em stable}. However, unlike the conventional two-channel Kondo (2CK) model, it has {\em four} leading irrelevant operators, implying that while the form of the singular temperature dependence of physical quantities is similar to the 2CK model, there will not be simple universal amplitude ratios. The phase diagram of this system is analyzed and a critical manifold is found to separate the non-Fermi-liquid from a conventional Fermi liquid fixed point. Generalization to higher symmetries, such as cubic, and the possibility of physical realizations with dynamic Jahn-Teller impurities is discussed.Comment: 20 pages, 4 figures, RevTex format, submitted to Phys. Rev.