Analisa Performa Hullform Pada PRA Perancangan Speed Boat Katamaran Untuk Search and Rescue ( Sar ) Di Pantai Gunungkidul YOGYAKARTA Berbasis Cfd

Kapal jenis speed boat merupakan kapal yang sering digunakan sebagai kapal penyelamat sehingga perlu pengembangan untuk mengetahui lebih dalam interaksi tahanan pada lambung kapal agar tercapainya kapal dengan stabilitas serta tahanan yang lebih baik. Kapal Motor Safinatul ‘Is ‘Aaf merupakan salah satu model kapal speed boat katamaran (lambung ganda) yang dirancang untuk menunjang pariwisata di wilayah Pantai Gunungkidul. Penelitian ini bertujuan untuk mengetahui lebih detail interaksi tahanan total pada lambung kapal K.M Safinatul ‘Is ‘Aaf dengan pendekatan Computational Fluid Dynamic. Dalam melaksanakan penelitian dilakukan beberapa tahapan yaitu pembuatan model pada Computational Fluid Dynamic, input data simulasi, running simulasi hingga konvergen, kemudian analisa hasil dengan metode Slender Body, CFD serta metode Insel and Molland. Analisa hasil meliputi analisa hambatan, dan analisa fluida pada simulasi Computational Fluid Dynamic. Berdasarkan hasil analisa dan perhitungan didapatkan hasil analisa yang menunjukkan bahwa hambatan total kapal (Rt) pada saat kecepatan kapal 29 knots Berdasarkan hasil analisa dan perhitungan yang dilakukan penulis dengan 3 dengan menggunakan metode CFD sebesar 10,85 kN, metode Slender Body sebesar 9.63 kN dan perhitungan secara analitik dengan metode Insel and Molland sebesar 12.05 kN. Sedangkan dari hasil simulasi dengan menggunakan analisa CFD, dapat diketahui bahwa pada saat kapal berjalan dengan kecepatan tinggi maka ketinggian aliran fluida atau gelombang air yang ditimbulkan akan lebih besar dari kapal yang berjalan dengan kecepatan renda

Pengaruh Komponen Arus Kas, Laba Akuntansi dan Dividend Yield terhadap Return Saham (Studi Empiris pada Perusahaan Manufaktur di Bei Periode 2011-2013)

This study aims to analyze the influence of three components of cash flow, net profit and dividend yield to the stock return on manufactur industries listed in Indonesian Stock Exchange (IDX) during 2011 to 2013. This study uses 105 samples of manufacturing firms that listed in Indonesian Stock Exchange (IDX) during 2011 to 2013. The sampling method used for this study is purposive sampling. Type of the data used is secondary data. Data analysis used are descriptive statistics, classical assumption tests and multiple regression analysis. Variables used in this study are variable cash flow from operating, cash flow from invesment, cash flow from financing, net profit and dividend yield as an independent variable; Stock Return as an dependent variable. The result showed that operation cash flow has positive and significantly impacted the stock return. invesment cash flow has positive and not significant impact to the stock return. financing cash flow has positif and significant impact to the stock return. Accounting profit has positive and not significantly impacted the stock return Meanwhile dividend yield has negative and not significant impact to the stock return

Desain Antena Array Mikrostrip Tapered Peripheral Slits Pada Frekuensi 2,4 Ghz Untuk Satelit Nano

Saat ini ITS sedang berpartisipasi dalam sebuah komunitas bernama INSPIRE yang mengerjakan sebuah proyek pembuatan satelit nano. Salah satu kriteria dari satelit tersebut adalah memiliki antena mikrostrip dengan frekuensi 2,4 GHz. Pada tugas akhir ini akan dibuat antena mikrostrip square agar sesuai dengan bentuk satelit nano dan susunan array secara paralel. Subtrat yang dipakai adalah FR04 Epoxy dengan konstanta dielektrik 4,3, ukuran subtrat adalah 10x10 cm. Patch square yang digunakan akan mengunakan pola Tapered Peripheral Slit untuk minimalisasi ukuran patch. Antena mikrostrip ini beroperasi pada frekuensi 2,4 GHz dengan parameter Return Loss < -10 dB, VSWR < 2 dan gain < 3,7 dBi. Untuk menghasilkan gain yang tinggi, antena mikrostrip ini menggunakan pencatuan aperture coupled. Teknik cross slot dikombinasikan dengan pencatuan aperture coupled agar menghasilkan polarisasi sirkuler pada antena.Hasil simulasi menunjukkan return loss antena sebesar -15,708 dB dengan bandwidth 34,4 MHz, VSWR 1,3922 dan gain 4,413 dBi. Sedangkan pengukuran pada antena yang telah direalisasikan menghasilkan return loss sebesar -30,894 dB dengan bandwidth 588,67 MHz, VSWR 1,191 dan gain 7,104 dBi

DESAIN LAMPU HIGH POWERED LIGHT EMMITING DIODE (HPL) UNTUK PENCAHAYAAN KARANG DAN IKAN PADA AKUARIUM DISPLAY

Suplai cahaya merupakan salah satu faktor penting dalam sistem akuarium display yang mengembangkan perpaduan biota laut beberapa jenis karang dan ikan. Minimalnya ketahanan hidup biota laut di dalamnya menjadi fokus latar belakang penelitian ini. Faktor krusial berupa kurangnya pengetahuan tentang kebutuhan cahaya yang diimplementasikan merupakan salah satu penyebabnya, sehingga dirumuskanlah tujuan penelitian yaitu membuat desain sistem pencahayaan bagi beberapa jenis karang dan ikan pada akuarium display. Metode yang diterapkan meliputi desain konseptual, eksplorasi, observasi, pengukuran, perhitungan, desain awal, dan desain rinci. Hasilnya berupa desain akuarium berdimensi 300 cm x 70 cm x 70 cm dengan kapasitas volume air laut 1.333,233 liter menggunakan lampu HPL sebanyak 564 unit yang dilengkapi LED driver (25-36 Watt, 160 Volt DC) sebanyak 24 unit dan terbagi dalam 12 blok. Setiap blok terdapat 47 lampu HPL (16 day light, 16 cool light, 15 warm white) yang dirangkai seri dan dikoneksikan dengan 2 unit LED driver. HPL disematkan pada heat sink aluminium sebagai pendingin. Sebagai duplikasi moon light, actinic blue ditempatkan sejauh 2 meter dari sisi luar akuarium. Kesimpulannya desain HPL untuk pencahayaan karang dan ikan pada akuarium display berhasil dibuat sesuai konsep kebutuhan intensitas, jenis, dan durasi pencahayaan terhadap dimensi akuarium dan jenis biota yang dipelihara

PENGARUH PERASAN DAUN LIDAH MERTUA (Sansevieria trifasciata prain) TERHADAP ANGKA KUMAN UDARA DI RUANG KELAS R226, R221, dan R222 KAMPUS 7 POLITEKNIK KESEHATAN KEMENKES SEMARANG TAHUN 2018

Latar belakang Kualitas udara di ruang perkuliahan perlu diperhatikan karena udara menjadi media penularan penyakit. Alternatif yang bisa digunakan adalah dengan pemanfaatan perasan daun lidah mertua (Sansevieria trifasciataprain).Tanaman lidah mertua memiliki berbagai manfaat salah satunya sebagai antibakteri.Hal ini dikarenakan dalam beberapa penelitian, tumbuhan Sansevieria diketahui memiliki potensi sebagai zat antibakteri. Tujuan menganalisis pengaruh perasan lidah mertua terhadap penurunan angka kuman udara di ruang R226, R221, dan R222 Jurusan Kesehatan Lingungan Politeknik Kesehatan Kemenkes Semarang Tahun 2018. Jenis penelitian ini adalah pra eksperimen dengan rancangan pre post design. Variable bebas perasan daun lidah mertua konsentrasi 10%,15%, dan 25%, variable terikat angka kuman udara. Hasil pemeriksaan angka kuman udara rata-rata sebelum  perlakuan diruang R226 didapatkan hasil 331.5 koloni/jam/feet2 dan rata setelah perlakuan 10% 355.33 koloni/jam/feet2. Pada R221 angka kuman sebelum perlakuan 355.5 koloni/jam/feet2 dan setelah perlakuan 233.167 koloni/jam/feet2. Pada R222 angka kuman sebelum perlakuan 433 koloni/jam/feet2 dan setelah perlakuan sebesar 225.5 koloni/jam/feet2. Dosis efektif perlakuan (10%,15% dan 25%) terhadap penurunan angka kuman udara ruang R226, R221 dan R222 adalah konsentrasi 15% sebesar 57.67 % dalam 4 ml/m3. Simpulan dari hasil penelitian bahwa secara statistik pemakaian perasan lidah mertua tidak ada pengaruh terhadap penurunan angka kuman udara di ruang kelas R226, R221 dan R222 Jurusan Kesehatan Lingkungan Politeknik Kesehatan Kemenkes Semarang. Disarankan sebaiknya meningkatkan kebersihan perilaku pengguna ruangan, lantai dibersihkan menggunakan antiseptik, membuka jendela dipagi hari sebelum menyalakan AC, dan untuk peneliti selanjutnya sebaiknya menggunakan butiran mist dengan konsentrasi perasan yang lebih tinggi

Effect of Soil Tillage and Adaptability of Argomulyo and Burangrang Varieties in Madagascar Dry Season with Cold Temperature

This research aimed to study soybean response to different soil tillage and soybean adaptability to dry season with cold temperature. Two Indonesian varieties (‘Argomulyo' and ‘Burangrang') and three Madagascar varieties (‘FT10', ‘OC11' and ‘Malady') were grown under soil tillage and no soil tillage in Antananarivo Avarandrano, Madagascar. The planting date was from June to November 2014 in which the season was dry season with average temperature ranging 14-19 oC. Results showed that there was no variety × tillage interaction on the observed characters. Tillage system was significantly different on plant height, number of pods plant-1, grain size, and grain yield. The differences among varieties were found on vegetative and generative phases, plant height, number of branches and pods plant-1, grain size, and grain yield. Cold temperature suppressed growth and development of vegetative and generative phases causing agronomical characters decreased. However, soybean plants were still able to grow and develop indicating that soybean can be grown under no tillage system with cold temperature. Indonesian varieties (‘Argomulyo' and ‘Burangrang') showed equal grain yield to Madagascar Varieties (‘FT10' and ‘OC11'), suggesting that ‘Argomulyo' and ‘Burangrang' were adaptable in Madagascar dry season with cold temperature

Development of a p84/zcc composite carbon membrane for gas separation of h2/co2 and h2/ch4

Hydrogen (H2) has become one of the promising alternative clean energy resources. Membrane technology is a potential method for hydrogen separation or production. This study aims to develop a new carbon membrane for hydrogen separation or production. Moreover, the permeation behavior of H2, CO2, and CH4 through a hollow fiber composite carbon membrane derived from P84 co-polyimide and with incorporation of zeolite composite carbon (ZCC) was also examined. ZCC was synthesized via the impregnation method of sucrose into zeolite-Y pores, followed by carbonization at 800 °C. Thus, this filler has a high surface area, high microporosity, ordered pore structure, and low hydrophilicity. The presence of zeolites in ZCC is predicted to increase certain gases' affinity for the membrane. Various heating rates (1-5 °C/min) were applied during pyrolysis to understand the effect of the heating rate on the pore structure and H2/CO2 and H2/CH4 gas separation performance. Moreover, gas permeation was evaluated at various temperatures (298-373 K) to study the thermodynamic aspect of the process. A characteristic graphite peak was detected at 2θ ∼44° in all carbon samples. Scanning electron microscopy (SEM) observations revealed the void-free surface and the asymmetric structure of the carbon membranes. During the permeation test, it was found that gas permeation through the membrane was significantly affected by the temperature of the separation process. The highest permeability of H2, CO2, and CH4 was detected on the composite carbon membrane at a 3 °C/min heating rate with a permeation temperature of 373 K. The thermodynamic study shows that CO2 and H2 have lower activation energies compared to CH4. The transport mechanism of the membrane involved adsorption and activated surface diffusion. The permeation temperature has a large impact on the transport of small penetrants in the carbon matrix

Internet addiction and its psychosocial risks (depression, anxiety, stress and loneliness) among Iranian adolescents and young adults: a structural equation model in a cross-sectional study

Internet addiction has become an increasingly researched area in many Westernized countries. However, there has been little research in developing countries such as Iran, and when research has been conducted, it has typically utilized small samples. This study investigated the relationship of Internet addiction with stress, depression, anxiety, and loneliness in 1,052 Iranian adolescents and young adults. The participants were randomly selected to complete a battery of psychometrically validated instruments including the Internet Addiction Test, Depression Anxiety Stress Scale, and the Loneliness Scale. Structural equation modeling and Pearson correlation coefficients were used to determine the relationship between Internet addiction and psychological impairments (depression, anxiety, stress and loneliness). Pearson correlation, path analysis, multivariate analysis of variance (MANOVA), and t-tests were used to analyze the data. Results showed that Internet addiction is a predictor of stress, depression, anxiety, and loneliness. Findings further indicated that addictive Internet use is gender sensitive and that the risk of Internet addiction is higher in males than in females. The results showed that male Internet addicts differed significantly from females in terms of depression, anxiety, stress, and loneliness. The implications of these results are discussed

Validation and psychometric analysis of the Internet Addiction Test in Spanish among college students

BACKGROUND: The wide use of the Internet in the workplace, academic or social field, can have an impact on daily life. One of the most used questionnaires worldwide to analyse these problems is the Internet Addiction Test (IAT). Our aim was to validate a Spanish version of the IAT and analyse its psychometric properties. METHODS: Population of study were college students participating in the uniHcos project (Universities of Granada, Huelva, Jaén, León, Salamanca, and Vigo). The questionnaire was translated and back-translated by two native English speakers. Reliability of scores was analysed using Pearson's correlation coefficient and agreement was analysed using the Bland-Altman and Kappa techniques. Test dimensions were analysed by exploratory and confirmatory factor analysis. RESULTS: The reliability of scores was good (r = 0.899, Kappa = 0.650 and mean difference using Bland-Altman = -3.5). The psychometric assessment identified two factors (Emotional Investment; Performance and Time Management) which explained 55 % of the variance (total internal consistency of 0.91) and only 19 items. The confirmatory analysis showed an acceptable goodness of fit, especially when items 6 and 8 were related (RMSEA = 0.07 90%IC = 0.06 - 0.08; WRMR = 1.01, CFI = 0.96; TLI = 0.95). The two dimensions were negatively correlated with age and positively correlated with time spent online, especially for the purposes of leisure and entertainment. DISCUSSION: The results show good reliability and psychometric properties of the Spanish version of IAT with a two-dimensional solution. This result is partially in concordance with previous validations of the IAT in other languages that have found uni- and multi-dimensional solutions using different methodologies. Moreover, we want to highlight the possibility that some item of this questionnaire is outdated due to the technological and lifestyles changes and should be not taken into account. CONCLUSION: The reliability and psychometric properties obtained in this study support the conclusion that this Spanish short version of the IAT represents a useful tool for the analysis of problems arising from misuse of the Internet