Complexity on dwarf galaxies scale: A bimodal distribution function in Sculptor

In previous work we have presented Schwarzschild models of the Sculptor dSph, demonstrating that this system could be embedded in dark matter halos that are either cusped or cored. Here we show that the non-parametric distribution function recovered through Schwarschild's method is bimodal in energy and angular momentum space for all best fitting mass models explored. We demonstrate that this bimodality is directly related to the two components known to be present in Sculptor through stellar populations analysis, although our method is purely dynamical in nature and does not use this prior information. It therefore constitutes independent confirmation of the existence of two physically distinct dynamical components in Sculptor and suggests a rather complex assembly history for this dwarf galaxy.Comment: 4 pages, 4 figures, 1 table, accepted to ApJ Letter

Matching the dark matter profiles of dSph galaxies with those of simulated satellites: a two parameter comparison

We compare the dark matter halos' structural parameters derived for four Milky Way dwarf spheroidal galaxies to those of subhalos found in cosmological $N$-body simulations. We confirm that estimates of the mass at a single fixed radius are fully consistent with the observations. However, when a second structural parameter such as the logarithmic slope of the dark halo density profile measured close to the half-light radius is included in the comparison, we find little to no overlap between the satellites and the subhalos. Typically the right mass subhalos have steeper profiles at these radii than measurements of the dSph suggest. Using energy arguments we explore if it is possible to solve this discrepancy by invoking baryonic effects. Assuming that feedback from supernovae can lead to a reshaping of the halos, we compute the required efficiency and find entirely plausible values for a significant fraction of the subhalos and even as low as 0.1%. This implies that care must be taken not to exaggerate the effect of supernovae feedback as this could make the halos too shallow. These results could be used to calibrate and possibly constrain feedback recipes in hydrodynamical simulations.Comment: 6 pages, 3 figures, submitted to ApJ

Characterization of Machinability and Environmental Impact of Cryogenic Turning of Ti-6Al-4V

Abstract Titanium alloys are widely used in aerospace applications due to their physical and mechanical properties. However, their poor machinability remains the main challenge to improve the productivity and the surface quality. Cryogenic machining recently gained interest as a clean and economical cooling technique. It becomes a promising candidate for applications that involve aggressive metal removal, especially for hard-to-cut material. This research provides insight into the cryogenic machining performance compared to flood machining in terms of its effect on tool life, surface quality, cutting forces and environmental impact. For such analysis, turning tests of Ti-6Al-4V using cryogenic and flood technologies were conducted at different cutting conditions. Life cycle analysis was conducted using the Eco-indicator method to compare the environmental impact of each technology. The cryogenic technology significantly improved the process environmental performance in addition to enhancing the tool life and surface quality compared to flood, hence improved the process productivity

POLA PENALARAN FISIKA PESERTA DIDIK SMA DALAM MEMAJUKAN RUMAH TERAPUNG DI DANAU TEMPE

Penelitian ini adalah penelitian kualitatif jenis fenomenografi. Penelitian ini bertujuan untuk mengetahui pola penalaran fisika peserta didik SMA dalam memajukan rumah terapung di danau tempe.  LKPD yang dirancang merujuk pada kearifan lokal di Wajo dengan objek “ Rumah Terapung di danau Tempe”. Subjek dalam penelitian ini adalah peserta didik kelas XI MIPA SMA Negeri 4 Wajo yang menyukai mata pelajaran fisika dan erat kaitannya dengan mata pelajaran IPA yang lain dan pernah berkunjung ke rumah terapung di danau Tempe. Pengumpulan data dilakukan melalui observasi, tes tulis, wawancara dan dokumentasi. Data hasil penelitian diperoleh melalui tes tulis dan dianalisis secara kualitatif. Hasil penelitian menunjukkan bahwa peserta didik mampu bernalar dan menggunakan pola penalaran deduktif dan induktif.

PENGEMBANGAN INSTRUMEN MATERI FISIKA KELAS XI UNTUK MENGUKUR KETERAMPILAN BERPIKIR KRITIS PESERTA DIDIK SMA NEGERI 8 MAKASSAR

Penelitian ini bertujuan untuk mengetahui prosedur dan menganalisis kualitas pengembangan instrumen materi fisika kelas XI agar dapat digunakan untuk mengukur keterampilan berpikir kritis peserta didik SMA. Jenis penelitian ini adalah penelitian pengembangan (Research and Development) dengan model pengembangan yang dikemukakan oleh Allen (1979) yang melalui 6 tahap yaitu plan the test, write item for each of the areas in the plan, administer all the item to a reasonably, conduct an item analysis, administer the revised test the another representative sample of examinee dan test standardization. Untuk mengetahui tujuan tersebut diperoleh koefisien validitas isi, koefisien reliabilitas, tingkat kesukaran dan daya pembeda butir instrumen. Subjek uji coba pada penelitian ini adalah peserta didik kelas XII IPA SMAN 8 Makassar terdiri dari 106 peserta  didik. Jumlah butir yang dikembangkan sebanyak 52 butir soal pilihan ganda. Hasil penelitian ini yaitu instrumen materi fisika kelas XI yang dikembangkan memiliki kualitas dengan kategori sangat layak berdasarkan hasil uji validasi ahli sebesar 0,96. Jumlah butir soal yang diujicobakan sebanyak 40 butir. Ujicoba instrumen dilakukan sebanyak dua kali dan menghasilkan koefisien reliabilitas sebesar 0,87 untuk ujicoba pertama dan ujicoba kedua. Dengan hasil analisis yang telah diperoleh maka instrumen materi fisika kelas XI yang dikembangkan tergolog valid dan reliabel baik secara teoretik maupun seara empirik. Sehingga menghasilkan instrumen tes yang baik dengan jumlah butir tes soal pilihan ganda sebanyak  33 butir soal. Kata Kunci : Instrumen Materi Fisika, Keterampilan Berpikir Kritis, Validitas, Reliabilita

Analisis Faktor Faktor yang Mempengaruhi Kepuasan Konsumen pada PT. Pln Sangatta

Awang Helmi,factor that influence coNsumer behavior for customer satisfaction of PT.PLN at sangatta under guidance of Mrs.DR.Titin Ruliana,SE,MM and Mrs.Mardiana,SE.MM. Consideration used byPLN Bontang to open a new Rayon at Sangatta is because the amount of electric power requirement from society and also company,besides the amont of samarinda townee which continue to increase PLN Rayon Upstream samarinda which stand from 2005 with 23.037 customers becomes an atracction because sangatta has the largest amount of townee compared to another city an east berneo province to market this PT.PLN sangatta branch need to now the factors the influence consumer behavior and satisfaction. The problem are the factors of services,service of goods,and Administration service will have significant effect to PT.PLN sangatta Custumer satisfaction,meanwhile the purpose of this research are to know and analyse consumer behavior,which consisted by services,service of good,and Administration service of PT.PLN Sangatta custumer satisfaction.analysis tool used multiple linear regretion with the help by SPSS version 10.00 program.regretion equation obtained is Y= 2.801+0.153X1 +0.165 X 2 + 0,188 X3 e. Based on the F test (concurrent test) obtained calculated F= 14.042 > table F = 2.467 so all of free variable have a significant influence to PT.PLN Sangatta branch customer satisfaction supported by R Square coefficient of 0,305 means 30,5 % influenced by the three free variables,and the other 69,5% Influenced by another Factor which not included in this research method. with the t test Obtained the three free variables t calculate>table t means zero hypothesis rejected and probability value of free variables<from alfa 5 % or 0,05 means all free variables are significant.free variable relation (X) namely services variables,service of goods and Administration services to tied variable (Y) is good custumer satisfaction showed by R correlation=0,552 approaching near 1 meanwhile from the consumer behavior factors, administration service have the largest influence to PT.PLN sangatta branch proved by value t calculated=2,554 and the largest standarited cooeficient beta=0,259. Based on this research showed the services,service of goods,and Administration service have significant influence to customer satisfaction and Administration service factor have the largest influence so the hipothesis accepted