Dynamic Power Spectral Analysis of Solar Measurements from Photospheric, Chromospheric, and Coronal Sources

An important aspect in the power spectral analysis of solar variability is the quasistationary and quasiperiodic nature of solar periodicities. In other words, the frequency, phase, and amplitude of solar periodicities vary on time scales ranging from active region lifetimes to solar cycle time scales. Here, researchers employ a dynamic, or running, power spectral density analysis to determine many periodicities and their time-varying nature in the projected area of active sunspot groups (S sub act). The Solar Maximum Mission/Active Cavity Radiometer Irradiance Monitor (SMM/ACRIM) total solar irradiance (S), the Nimbus-7 MgII center-to-wing ratio (R (MgII sub c/w)), the Ottawa 10.7 cm flux (F sub 10.7), and the GOES background x ray flux (X sub b) for the maximum, descending, and minimum portions of solar cycle 21 (i.e., 1980 to 1986) are used. The technique dramatically illustrates several previously unrecognized periodicities. For example, a relatively stable period at about 51 days has been found in those indices which are related to emerging magnetic fields. The majority of solar periodicities, particularly around 27, 150 and 300 days, are quasiperiodic because they vary in amplitude and frequency throughout the solar cycle. Finally, it is shown that there are clear differences between the power spectral densities of solar measurements from photospheric, chromospheric, and coronal sources

Modeling Solar Lyman Alpha Irradiance

Solar Lyman alpha irradiance is estimated from various solar indices using linear regression analyses. Models developed with multiple linear regression analysis, including daily values and 81-day running means of solar indices, predict reasonably well both the short- and long-term variations observed in Lyman alpha. It is shown that the full disk equivalent width of the He line at 1083 nm offers the best proxy for Lyman alpha, and that the total irradiance corrected for sunspot effect also has a high correlation with Lyman alpha

In situ CCVD synthesis of carbon nanotubes within a commercial ceramic foam

Consolidated nanocomposite foams containing a large quantity of carbon nanotubes (CNTs) within millimetre-sized pores are prepared for the first time. A commercial ceramic foam is impregnated by a 60 g L21 slurry of a (Mg(12x)(Co0.75Mo0.25)xO solid solution (x = 0.01, 0.05, 0.1 and 0.2) powder in ethanol. Three successive impregnations led to deposits several tens of mm thick, with a good coverage of the commercial-ceramic pore walls but without closing the pores. The materials were submitted to a CCVD treatment in H2–CH4 atmosphere in order to synthesise the CNTs. When using attrition-milled powders, the carbon is mostly in the form of nanofibres or disordered carbon rather than CNTs. Using non-milled powders produces a less-compact deposit of catalytic material with a higher adherence to the walls of the ceramic foam. After CCVD, the carbon is mostly in the form of high-quality CNTs, as when using powder beds, their quantity being 2.5 times higher. The so-obtained consolidated nanocomposite materials show a multi-scale pore structuration

Pitfalls during biomechanical testing — Evaluation of different fixation methods for measuring tendons endurance properties

The goal of the study was to find a proper technique to fix tendon grafts into an INSTRON loading machine. From 8 human cadavers, 40 grafts were collected. We removed the bone-patella tendon-bone grafts, the semitendinosus and gracilis tendons, the quadriceps tendon-bone grafts, the Achilles tendons, and the peroneus longus tendons from each lower extremity. We tested the tendon grafts with five different types of fixation devices: surgical thread (Premicron 3), general mounting clamp, wire mesh, cement fixation, and a modified clamp for an INSTRON loading machine. The mean failure load in case of surgical thread fixation was (381N ± 26N). The results with the general clamp were (527N ± 45N). The wire meshes were more promising (750N ± 21N), but did not reach the outcomes we desired. Easy slippages of the ends of the tendons from the cement encasements were observed (253N ± 18N). We then began to use Shi’s clamp that could produce 977N ± 416N peak force. We combined Shi’s clamp with freezing of the graft and the rupture of the tendon itself demonstrated an average force of 2198 N ± 773N. We determined that our modified frozen clamp fixed the specimens against high tensile forces

Evolution of surname distribution under gender-equality measurements

We consider a model for the evolution of the surnames distribution under a gender-equality measurement presently discussed in the Spanish parliament (the children take the surname of the father or the mother according to alphabetical order). We quantify how this would bias the alphabetical distribution of surnames, and analyze its effect on the present distribution of the surnames in Spain

PENGUKURAN BEBAN KERJA OPERATOR DENGAN MENGGUNAKAN METODE DEFENSE RESEARCH AGENCY WORKLOAD SCALE (DRAWS) STUDI KASUS DI CV. SUPERB MANUFACTURED, BANDUNG

Pada era globalisasi ini perusahaan dituntut untuk memproduksi produk dengan kapasitas produksi yang besar untuk dapat mencapai target sehingga menghasilkan keuntungan yang besar pula namun disamping itu harus diimbangi dengan kualitas produk yang baik dan tingkat kecelakaan kerja yang sangat kecil. Keselamatan kerja merupakan hal yang penting bagi perusahaan, karena dampak kecelakaan kerja tidak hanya merugikan karyawan, tetapi juga perusahaan baik secara langsung maupun tidak langsung. Terdapat beberapa pengertian tentang keselamatan dan kesehatan kerja yang didefinisikan oleh beberapa ahli, dan pada dasarnya definisi tersebut mengarah pada interaksi pekerja dengan mesin atau peralatan yang digunakan, interaksi pekerja dengan lingkungan kerja, dan interaksi pekerja dengan mesin dan lingkungan kerja. Keselamatan kerja berarti proses merencanakan dan mengendalikan situasi yang berpotensi menimbulkan kecelakaan kerja melalui persiapan prosedur operasi standar yang menjadi acuan dalam bekerja. Oleh karena itu masalah tersebut akan diteliti menggunakan metoda Defence Research Agency Workload Scale (DRAWS) dengan 4 variabel beban kerja yaitu Input Demand, Central Demand, Output Demand dan Time Pressure. CV. Superb Manufactured merupakan perusahaan yang bergerak di bidang konveksi yang memproduksi pakaian jadi. Perusahaan ini memproduksi berbagai macam produk pakaian jadi seperti berbagai jenis t-shirt, hoodie, zip hoodie, crewneck, snapback, polo shirt, parka, trucker hat dan lain-lain. Namun kegiatan produksi yang lebih sering adalah memproduksi kaos atau t-shirt. Dalam kegiatan produksinya, perusahaan ini membuat produknya sesuai dengan pesanan (make to order) dan juga menggunakan sistem (make to stock) atau membuat barang jadi untuk persediaan penjualan langsung.Tingginya beban kerja yang dirasakan operator bagian produksi menjadi penting untuk melakukan analisis beban kerja. Sehingga yang menjadi rumusan masalah pada penelitian kali ini adalah seberapa besar beban kerja yang dirasakan operator setiap bagian produksi di CV. Superb Manufactured, variabel beban kerja metode DRAWS apa saja yang paling dominan dirasakan oleh setiap operator di bagian produksi termasuk beban kerja fisik atau beban kerja mental. Dari hasil rata-rata rekapitulasi beban kerja yang dirasakan operator di setiap bagian produksi menunjukkan bahwa operator yang bekerja di bagian pembuatan sample hingga packing termasuk kedalam beban kerja mental. Hanya saja pada operator QC termasuk kedalam kategori beban kerja fisik. Rata-rata skor beban kerja mental pada bagian pembuata sample yaitu 56.3%, pembuatan pola 60%, grading 52.5%, cutting 71%, sablon 55%, sewing 67%, finishing 55%, inspeksi akhir 60% dan packing 59%. Dan operator QC kedalam kategori beban kerja fisik dengan nilai rata-rata 53%. Rata-rata skor beban kerja mental seluruh operator yang bekerja di bagian produksi adalah 58.2%, sehingga termasuk kedalam kategori beban kerja mental. Jadi beban kerja yang dirasakan oleh setiap operator produksi termasuk kedalam kategori beban kerja mental karena lebih banyak aktivitas berfikir agar tujuan dan target dari pekerjaan tercapai. Beban kerja mental berpengaruh terhadap konsentrasi dan perhatian yang dibutuhkan karyawan untuk mengerjakan suatu tugas. Apabila beban kerja mental rendah maka konsntrasi dan perhatian yang dibutuhkan untuk mengerjakan suatu tugas akan minimal jumlahnya. Kata Kunci: Beban Kerja Fisik, Mental, DRAWS, Operato

Synovial fibroblasts: key players in rheumatoid arthritis

Rheumatoid arthritis (RA) is a chronic autoimmune-disease of unknown origin that primarily affects the joints and ultimately leads to their destruction. The involvement of immune cells is a general hallmark of autoimmune-related disorders. In this regard, macrophages, T cells and their respective cytokines play a pivotal role in RA. However, the notion that RA is a primarily T-cell-dependent disease has been strongly challenged during recent years. Rather, it has been understood that resident, fibroblast-like cells contribute significantly to the perpetuation of disease, and that they may even play a role in its initiation. These rheumatoid arthritis synovial fibroblasts (RASFs) constitute a quite unique cell type that distinguishes RA from other inflammatory conditions of the joints. A number of studies have demonstrated that RASFs show alterations in morphology and behaviour, including molecular changes in signalling cascades, apoptosis responses and in the expression of adhesion molecules as well as matrix-degrading enzymes. These changes appear to reflect a stable activation of RASFs, which occurs independently of continuous exogenous stimulation. As a consequence, RASFs are no longer considered passive bystanders but active players in the complex intercellular network of R

Solution of gauge theories induced by fundamental representation scalars

Gauge theories induced by scalars in the fundamental representation of the $U(N_c)_{gauge}\times U(N_f)_{global}$ group are investigated in the large $N_c$ and $N_f$ limit. A master field is defined from bilinears of the scalar field following an Eguchi-Kawai type reduction of spacetime. The density function for the master field satisfies an integral equation that can be solved exactly in two dimensions (D=2) and in a convergent series of approximations at $D>2$. While at D=2 the system is in the same phase at all $\epsilon=N_c/N_f$, it undergoes a phase transition at a critical value, $\epsilon_c(D)$, for $D>2$.Comment: 12 pages, LaTe

A q-deformed nonlinear map

A scheme of q-deformation of nonlinear maps is introduced. As a specific example, a q-deformation procedure related to the Tsallis q-exponential function is applied to the logistic map. Compared to the canonical logistic map, the resulting family of q-logistic maps is shown to have a wider spectrum of interesting behaviours, including the co-existence of attractors -- a phenomenon rare in one dimensional maps.Comment: 17 pages, 19 figure