Response of the Asian Summer Monsoons to a High-latitude Thermal Forcing: Mechanisms and Nonlinearities

This study investigates mechanisms and nonlinearities in the response of the Asian Summer Monsoons (ASM) to high-latitude thermal forcings of different amplitudes. Using a suite of runs carried out with an intermediate-complexity atmospheric general circulation model, we find that the imposed forcings produce a strong precipitation response over the eastern ASM but a rather weak response over the southern ASM. The forcing also causes a precipitation dipole with wet conditions over the eastern Tibetan Plateau (TP) and dry conditions over the Bay of Bengal (BoB) and southeast Asia. A moderate increase of precipitation along the southern margin of the TP is also produced. Simulations designed to isolate the causal mechanisms show that thermodynamic interactions involving the tropical surface oceans are far less important than the water-vapour feedback for the transmission of information from the high-latitudes to the ASM. Additionally, we assess the nonlinearity of the ASM precipitation response to the forcing amplitude using a novel application of the empirical orthogonal function method. The response can be decomposed in two overlapping patterns. The first pattern represents a precipitation dipole with wet conditions over the eastern TP and dry conditions over BoB, which linearly increases with forcing amplitude becoming quasi-stationary for large forcing amplitudes (i.e. amplitudes leading to Arctic temperature anomalies larger than 10 degrees C). The second pattern is associated with increased precipitation over the southeastern TP and is nonlinearly dependent on forcing, being most important for intermediate forcing amplitudes (i.e. amplitudes leading to Arctic temperature anomalies between 5 and 10 degrees C)

Near neighbour correlations and the dielectric properties of liquid crystals

It is demonstrated experimentally that there can be a reversal of the sign of the dielectric anisotropy (Δε) with decreasing temperature in a nematic. The results are explainable in terms of the Maier-Meier mean field theory and indicate that the occurrence of the smectic phase and the consequent dipole correlations within the smectic layers is not a necessary condition for the sign reversal of Δε

Some comments on the determination of enthalpies of liquid crystalline transitions by differential scanning calorimetry

We demonstrate a simple practical method of improving the accuracy of determination of enthalpies of liquid crystalline transitions by differential scanning calorimetry. The method involves measurements at different heating rates and interpolation to zero heating rate

Pressure dependence of the pitch of cholesteryl oleyl carbonate

Pollmann and Stegemeyer have shown that the pitch of a cholesteric mixture of cholesteryl oleyl carbonate (COC) and cholesteryl chloride (CC) increases very rapidly with pressure, approaching infinity at a critical pressure pc whose value depends on the composition of the mixture. At first sight, this result is surprising as one would anticipate only slight "red shift" when the sample is compressed. The aim of this note is to show that the observed critical divergence is in fact to be expected from theoretical considerations

Bulk phantom fields, increasing warp factors and fermion localisation

A bulk phantom scalar field (with negative kinetic energy) in a sine--Gordon type potential is used to generate an exact thick brane solution with an increasing warp factor. It is shown that the growing nature of the warp factor allows the localisation of massive as well as massless spin-half fermions on the brane even without any additional non--gravitational interactions. The exact solutions for the localised massive fermionic modes are presented and discussed. The inclusion of a fermion--scalar Yukawa coupling appears to change the mass spectrum and wave functions of the localised fermion though it does not play the crucial role it did in the case of a decreasing warp factor.Comment: 11 pages, 3 figures, RevTex

Perancangan Sistem Pemeliharaan Menggunakan Metode Reliability Centered Maintenance (RCM) pada Pulverizer (Studi Kasus: PLTU Paiton Unit 3)

PLTU Paiton Unit 3 merupakan Perusahaan yang bergerak di bidang produksi listrik menggunakan bahan baku batubara yang terletak di Paiton, Probolinggo. Untuk mencapai target, proses produksi dilakukan 24 jam selama 1 tahun tanpa henti. Program pemeliharaan mesin sangat penting untuk kelancaran proses produksi. Dalam rangka mencapai target tersebut dituntut adanya kelancaran batubara dari silo hingga surface burner menggunakan pulverizer. Data dari Departemen Engineering menunjukkan bahwa beberapa subsistem pulverizer sering mengalami kerusakan yang dapat menimbulkan kegagalan pada sistem tersebut. Penelitian tugas akhir ini menggunakan metode Reliability Centered Maintenance (RCM) untuk menurunkan tingkat breakdown mesin dan downtime produksi. Data historis kerusakan pulverizer dianalisa. Kemudian kegagalan dari suatu komponen yang dapat menyebabkan kegagalan fungsi dari sistem diidentifikasi menggunakan metode Failure Mode and Effect Analysis (FMEA). Selanjutnya menggunakan RCM Decision Worksheet untuk mengetahui bagian dari sistem yang gagal dan perlu dilakukan tindakan perbaikan dan pencegahan berdasarkan kegagalan yang ada agar kejadian yang sama tidak terulang dan menentukan kegiatan perancang perawatan yang tepat pada setiap komponen Berdasarkan analisis data secara Reliability Centered Maintenance (RCM) terdapat 12 failure mode yang terjadi pada pulverizer. 3 failure mode dapat dicegah dengan scheduled restoration task, 8 failure mode dapat dicegah dengan scheduled discard task, dan 1 failure mode dapat dicegah dengan redesign. Analisis kuantitatif menggunakan distribusi kegagalan dengan perangkat lunak Weibull++6 didapatkan MTBF grinding roller 2880,66 jam, MTBF hydraulic pump 5075,06 jam, MTBF gearbox 5381,65 jam dan MTBF coal feeder 525,17 jam

Normalisasi Dan Pembobotan Untuk Kloning Mulus Pada Pencampuran Citra Menggunakan Metode Poisson

Pada penelitian ini diterapkan normalisasi dan pembobotan pada teknik pencampuran dengan metode Poisson sehingga dapat diperoleh citra hasil pencampuran. Dengan teknik ini, daerah batas antara dua citra yang dicampur dapat menyatu dengan sempurna tanpa harus melakukan penyuntingan gambar secara manual. Citra asal yang akan dicampur ke dalam citra target disegmentasi terlebih dahulu menggunakan metode ambang batas untuk membuat topeng. Metode Poisson diterapkan pada citra masukan dan target untuk mendapatkan nilai yang setelah dinormalisasi ke dalam [0 1] akan menjadi bobot dalam perhitungan nilai piksel baru pada daerah perbatasan antara citra asal dan target. Percobaan yang dilakukan pada sejumlah citra menunjukkan bahwa penggunaan bobot ternormalisasi hasil perhitungan Poisson memberikan efek keabuan yang makin meningkat mendekati batas luar citra asal. Hal ini menunjukkan bahwa prosentase nilai piksel pada batas terluar citra asal lebih besar dibandingkan dengan daerah batas bagian dalam. Perhitungan Kloning Mulus yang dilakukan dengan pembobotan tersebut menghasilkan gambar asal yang menyatu secara sempurna dengan citra target

Tanggap Pertumbuhan Dan Produksi Beberapa Varietas Kedelai (Glycine Max L.) Terhadap Perbandingan Komposisi Pupuk

The use of organic fertilizer is needed to replace the role of chemical fertilizers, preserving theenvironment and for sustainable agriculture. The study was conducted in Tanjung Sari, KecamatanMedan Selayang. The research used a Randomized Block Design with two factors. The first factoris varieties (Argomulyo, Burangrang and Anjasmoro). The second factor is the ratio of chemicalfertilizers and vermicompost, which include : chemical fertilizer 0% + vermicompost 100%,chemical fertilizer 25% + vermicompost 75%, chemical fertilizer 50% + vermicompost 50%,chemical fertilizer 25% + vermicompost 75%, and chemical 100% + vermicompost 0%. The resultshowed that Varieties significantly affected the parameters amount of produtive branch, weight ofdry plant, weight of dry root, the number of pods per plant, the number of filled pods per plant,weight of dry seed per sample,and weight of 100 seeds. Varieties did not significantly affect theparameters weight of dry seed per plot. The composition ratio of fertilizers significantly affectedthe parameters weight of dry root, weight of dry seed per sample,and weight of 100 seeds. Inaddition, the ratio of chemical fertilizers and vermicompost did not significantly affect theparameters amount of produtive branch, weight of dry plant, the number of pods per plant, thenumber of filled pods per plant,and weight of dry seed per plot. The interaction between varietiesand the ratio of chemical fertilizers and vermicompost did not significantly affected for allparameters

A thermotropic biaxial nematic liquid crystal

Optical studies have been carried out on a nematogenic copper complex, which incorporates the features of both rod-like and disk-like molecules. Conoscopic figures are presented demonstrating (i) the occurrence of a biaxial nematic phase in the pure complex, (ii) the uniaxial-biaxial (Na-Nb) transition in binary mixtures, and (iii) the temperature variation of the biaxiality near this transition. The I-Na-Nb phase diagram has been studied for the binary system

Model Studi Kelayakan Investasi Proyek Perumahan Sederhana

Meningkatnya kebutuhan akan Perumahan sederhana memunculkan peluang investasi. Dengan metode investasi proyek Perumahan sederhana yang tepat maka investor dapat memperoleh tingkat pengembalian modal yang layak. Untuk itu, diperlukan sebuah model yang dapat digunakan untuk melakukan studi kelayakan dari sebuah rencana investasi proyek Perumahan sederhana. Pengguna model studi kelayakan ini dapat dengan secara subjektif memasukkan nilai input sesuai dengan rencana investasi proyek Perumahan sederhana yang dimiliki pengguna. Model ini berupa program sederhana menggunakan Microsoft Excel yang akan menghitung nilai Internal Rate of Return. Tiga skenario cash flow dalam model ini dibuat untuk optimistic cash flow, most-likely cash flow, dan pessimistic cash flow yang dibuat sesuai dengan rencana investasi pengguna. Kelayakan sebuah rencana investasi proyek Perumahan sederhana akan dilihat dari tingkat Internal Rate of Return yang dibandingkan dengan Minimum Attractive Rate of Return. Hasil perbandingan ini kemudian akan digunakan oleh para investor atau developer sebagai bahan pengambilan keputusan