Fast acoustic streaming in standing waves : Generation of an additional outer streaming cell

Rayleigh streaming in a cylindrical acoustic standing waveguide is studied both experimentally and numerically for nonlinear Reynolds numbers from 1 to 30. Streaming velocity is measured by means of laser Doppler velocimetry in a cylindrical resonator filled with air at atmospheric pressure at high intensity sound levels. The compressible Navier-Stokes equations are solved numerically with high resolution finite difference schemes. The resonator is excited by shaking it along the axis at imposed frequency. Results of measurements and of numerical calculation are compared with results given in the literature and with each other. As expected, the axial streaming velocity measured and calculated agrees reasonably well with the slow streaming theory for small ReNL but deviates significantly from such predictions for fast streaming (ReNL > 1). Both experimental and numerical results show that when ReNL is increased, the center of the outer streaming cells are pushed toward the acoustic velocity nodes until counter-rotating additional vortices are generated near the acoustic velocity antinodes

Faktor-Faktor yang Berhubungan dengan Kelelahan Kerja pada Pekerja Konveksi Bagian Penjahitan di CV. Aneka Garment Gunungpati Semarang

Fatigue can be influenced by several factors that can come from within the individual as well as of the work environment. CV. Aneka Garment Gunungpati Semarang is informal industry convection with all the sewing workers are women. The purpose of this research is to analyze the related factors of fatigue on sewing workers at CV. Aneka Garment Gunungpati Semarang. This research is explanatory research using cross sectional study design, where population numbers to the workers is 31 people. Sampling method using total sampling. Data analysis using Chi-Square test for normal distribution of data and Rank-Spearman for data not normally distributed. The results showed that most of respondents heavy work fatigue (71%), most of the old ³40 years (71%), the majority of respondents work >10 years (71%), nutritional status of most respondents in the normal category (50.1%), the posture of most respondents work at level 3 (42.1%), and most of the workload between 30 to <60% (42.1%), it means need repairation for workload. Results of statistical tests showed had relationship between age and fatigue (p = 0.0001), there is a relationship between the during work with fatigue (p = 0.0001), there is no relationship between nutritional status with fatigue (p = 0.191), there is a relationship between working posture with fatigue (p = 0.0001), and there is a relationship between the workload with fatigue (p = 0.0001). Business owners should provide additional lighting in accordance with the type of work (lighting meets 1000 Lux) and doing engineering work station (chair) to fit the body size of worker

Penerapan Media Mind Mapping Programpada Model Pembelajaran Contextual Teaching and Learning (Ctl) Untuk Meningkatkan Motivasi Dan Hasil Belajar Fisika Pada Siswa Kelas Xi.a2 SMA Negeri 4 Surakarta

Penelitian ini bertujuan untuk mengetahui: (1) Penggunaan Mind Mapping Program melalui model pembelajaran Contextual Teaching Learning (CTL) dapat meningkatkan motivasi belajar fisika siswa. (2) Penggunaan Mind Mapping Program melalui model pembelajaran Contextual Teaching Learning (CTL) dapat meningkatkan hasil belajar fisika siswa.Penelitian ini merupakan Penelitian Tindakan Kelas (Classroom Action Research) yang dilaksanakan dalam dua siklus. Setiap siklus terdiri dari tahap perencanaan tindakan, pelaksanaan tindakan, observasi, dan refleksi. Subyek penelitian adalah siswa kelas XI.A2 SMA Negeri 4 Surakarta tahun pelajaran 2012/2013 yang dikhususkan pada materi pokok fluida dinamis sebanyak 30 siswa. Data diperoleh melalui pengamatan, review tanggapan guru, tes, dan dokumentasi. Teknik analisis data yang digunakan adalah analisis deskriptif kualitatif. Berdasarkan observasi yang telah dilakukan selama penelitian berlangsung dapat disimpulkan bahwa: (1) penerapan Mind Mapping Program melalui model pembelajaran Contextual Teaching Learning (CTL) dapat meningkatkan motivasi belajar fisika siswa kelas XI.A2 SMA Negeri 4 Surakarta Tahun Ajaran 2012/2013 pada materi pokok fluida dinamis. Peningkatan motivasi belajar fisika siswa terbukti dengan analisis lembar observasi motivasi belajar siswa selama penelitian berlangsung, yang pada awalnya rata-rata tiap indikator motivasi belajar siswa sebesar 21,67%, siklus I menjadi 52%, dan pada siklus II menjadi 53,33%. (2) Mind Mapping Program melalui model pembelajaran Contextual Teaching Learning (CTL) dapat meningkatkan hasil belajar fisika siswa kelas XI.A2 SMA Negeri 4 Surakarta Tahun Ajaran 2012/2013 pada materi pokok fluida dinamis. Peningkatan hasil belajar fisika siswa berdasarkan aspek kognitif yakni ketuntasan belajar fisika oleh siswa pada siklus I sebesar 83,33% yang kemudian meningkat menjadi 90% pada siklus II dari target yang ditetapkan yakni ketuntasan belajar siswa sebesar 75%

Clustering Data Non-numerik Dengan Pendekatan Algoritma K-means Dan Hamming Distance Studi Kasus Biro Jodoh

Clustering adalah salah satu metode populer yang telah digunakan di berbagai bidang penelitian mulai dari kecerdasan buatan, teknologi jaringan syaraf, pengenalan pola, hingga pengolahan gambar. Salah satu teknik yang digunakan dalam clustering adalah dengan menggunakan algoritma k-means. Namun sayangnya, algoritma k-means hanya bisa digunakan untuk dataset yang atributnya bernilai numerik. Padahal dalam Kenyataannya, suatu database bisa terdiri atas data-data yang bernilai numerik maupun non-numerik. Dalam penelitian ini akan dibahas mengenai penggunaan algoritma k-means pada suatu clustering data non-numerik (categorical), dengan dibantu Hamming Distance sebagai alat untuk mengukur distance dari masing-masing atribut categorical-nya. Kasus yang diambil adalah pada dataset suatu biro jodoh yang mana akan menjadi menarik karena dengan clustering ini dapat diketahui bagaimana pola pembentukan grup-grup yang memiliki karakteristik hampir sama di dalam keanggotaan suatu biro jodoh. Pada penelitian ini juga akan diberikan implementasi penggunaan clustering dalam pencarian individu di suatu data biro jodoh. Metodologi yang digunakan dalam penelitian ini meliputi beberapa tahapan. Tahapan pertama adalah persiapan data, yaitu data-data keanggotaan biro jodoh. Tahapan selanjutnya adalah proses modifikasi data dari non-numerik menjadi numerik. Kemudian tahap perhitungan distance antar-data. Lalu tahapan clustering pada data yang teleh bernilai jarak. Dan diakhiri dengan tahapan ringkasan dari hasil proses-proses tersebut. Uji coba dan evaluasi dilakukan dengan menggunakan dataset nyata yaitu data biro jodoh Grasco, Sakinah Surabaya, Libe, dan O\u27Diva. Dari uji coba tersebut didapatkan bahwa clustering dapat dilakukan pada atribut-atribut categorical yang ditransformasikan terlebih dahulu ke dalam bentuk numerik. Selain itu, kesamaan (similarity) dan karakterisktik dari masing-masing keanggotaan biro jodoh bisa diketahui

Involving pregnant women, mothers and members of the public to improve the quality of women's health research

Katie’s Team is funded by a grant from the Centre for Public Engagement Queen Mary University of London

Factors associated with use and discontinuation of Implanon contraceptive in Jos, Nigeria

Background: the contraceptive prevalence (CPR) in sub-Saharan Africa is low at 8-10% for over a decade. There is also the dominance of the less effective short-acting methods such as pills and injectables. The low CPR is the direct cause of the high total fertility of 5.7 in Nigeria. The use of contraception is the single most dominant contributory factor in fertility declines world-wide. This is especially more true with the use of long acting reversible contraceptive methods like implanon which has the potential to reduce the global burden of disease and mortality associated with a high total fertility rate.Objective: our aim was to analyse and determine the socio-demographic profiles of implanon acceptors and the factors associated with continuation or discontinuation of its use in the family planning programme of the Jos University Teaching Hospital, Jos Nigeria.Materials and Methods: This was a retrospective review carried out between March 2007 and March 2014 at the Jos University Teaching Hospital, Jos NigeriaResults: during the study period, 1482 women accepted implanon with about 85.8% having regular menstrual cycles. Sixty-one percent of these women were breastfeeding at insertion. Their mean age was 31 years with a range of 16 to 53. Christianity was the religion of 87.8% with 12.2% being Muslims. Just under half had tertiary education with over a third having attended secondary school. About 26.7% had no future fertility desires. Over 75% had previously used a contraceptive method. The mean parity in this study was 3.2 with a range of 0 to 12. The mean number of children alive was 2.9. Both the systolic and diastolic blood pressures were little affected by the use of implanon. However there was a mean weight gain among 900 of the women who came for follow up of 2.4 kg. However the weight change was highly variable with about a third of women losing between 1 to 30 kg, 10% not having any net changes and over 61% having a net weight gain of between 1 to 26 kg. About 3.8% had their implanon removed because of weight gain. The percentage loss to follow up was 28.2%. The 900 women who had follow up were exposed to the implanon for 2006.6 woman-years or 24,079 cycles. The mean number of months of exposure to the implant was 27.0 ± 14.7 months. The commonest reason for discontinuation was desire for pregnancy (36.1%) followed by those who changed to other methods (27.6%). Menstrual irregularity was the commonest side effect of implanon that led to removal. Seven in-treatment pregnancies occurred giving a pearl index of 0.35 although only one pregnancy was ultrasonographically-proven to be a method failure of the device.Conclusion: Accepting implanon was influenced by the educational attainment and religion of the women in our unit. The desire for another pregnancy was the commonest reason for discontinuation. However, menstrual irregularity was the commonest side effect of the implant that led to its removal especially in the first six months after insertion.Keywords: Implanon (etonogestrel) contraceptive, continuation rates, discontinuation, reason for discontinuation

Revisiting the basis for haemoglobin screening in pregnancy

"This is a non-final version of an article published in final form in Current Opinion in Obstetrics and Gynecology: December 2019 - Volume 31 - Issue 6 - p 388–392 doi: 10.1097/GCO.0000000000000580