PERENCANAAN BIAYA BERDASARKAN JUMLAH DAN WAKTU PEMESANAN DENGAN METODE MRP (MATERIAL REQUIREMENT PLANNING) (STUDI KASUS:DILAKUKAN PADA PROYEK PEMBANGUNAN TERMINAL AKAP TANGKOKO BITUNG)

Perencanaan pengadaan material pada dasarnya merupakan masalah yang sangat penting dalam pelaksanaan kegiatan proyek. Apabila terjadi kelebihan atau kekurangan persediaan bahan dapat mengganggu kelancaran proyek. Pada prinsipnya, perencanaan pengadaan material yang tidak baik akan menimbulkan jalannya kegiatan proyek akan terhambat. Perencanaan pengadaan bahan (Material Requirement Planning) adalah suatu metode untuk menentukan kapan suatu material harus tersedia dan berapa banyak material yang dibutuhkan pada pelaksanaan proyek. Lot - Sizing merupakan langkah dasar dari Material Requirement Planning dalam menentukan jumlah suatu bahan yang harus dipesan untuk mendapatkan biaya-biaya persediaan yang optimum. Teknik lot-sizing yang dipilih adalah Part Period Balancing. Penelitian ini bertujuan mempelajari sejauh mana metode ini dapat merencanakan pengadaan material pada proyek pembangunan terminal AKAP Tangkoko Kota Bitung, untuk mengembangkan model penerapan teknik part period balancing kedalam proyek yang dikendalikan dengan Master Schedule. Keluaran kebutuhan bahan tiap periode dari pendistribusian material tersebut merupakan kebutuhan kotor. Untuk melakukan lot-zing diperlukan data-data ongkos persediaan. Berdasarkan status persediaan proyek dapat diperoleh kebutuhan bersih yang akan digunakan dalam proses lot-sizing, untuk menentukan besarnya pesanan serta persediaan-persediaan bahan yang timbul pada tiap periode. Kemudian berdasarkan waktu ancang yang dimiliki, dapat ditentukan waktu pemesanan.Hasil penelitian menunjukkan bahwa metode Material Requirement Planning dengan teknik Part Period Balancing dapat dikendalikan dengan Master schedule, dan dapat mereduksi persediaan diproyek serta mengoptimalkan biaya persediaan. Kata kunci: perencanaan biaya, pengadaan material, MRP, Lot-Sizing, Part Period Balancin

The W43-MM1 mini-starburst ridge, a test for star formation efficiency models

Context: Star formation efficiency (SFE) theories are currently based on statistical distributions of turbulent cloud structures and a simple model of star formation from cores. They remain poorly tested, especially at the highest densities. Aims: We investigate the effects of gas density on the SFE through measurements of the core formation efficiency (CFE). With a total mass of $\sim2\times10^4$ M$_\odot$, the W43-MM1 ridge is one of the most convincing candidate precursor of starburst clusters and thus one of the best place to investigate star formation. Methods: We used high-angular resolution maps obtained at 3 mm and 1 mm within W43-MM1 with the IRAM Plateau de Bure Interferometer to reveal a cluster of 11 massive dense cores (MDCs), and, one of the most massive protostellar cores known. An Herschel column density image provided the mass distribution of the cloud gas. We then measured the 'instantaneous' CFE and estimated the SFE and the star formation rate (SFR) within subregions of the W43-MM1 ridge. Results: The high SFE found in the ridge ($\sim$6% enclosed in $\sim$8 pc$^3$) confirms its ability to form a starburst cluster. There is however a clear lack of dense cores in the northern part of the ridge, which may be currently assembling. The CFE and the SFE are observed to increase with volume gas density while the SFR steeply decreases with the virial parameter, $\alpha_{vir}$. Statistical models of the SFR may well describe the outskirts of the W43-MM1 ridge but struggle to reproduce its inner part, which corresponds to measurements at low $\alpha_{vir}$. It may be that ridges do not follow the log-normal density distribution, Larson relations, and stationary conditions forced in the statistical SFR models.Comment: 13 pages, 7 figures. Accepted by A&

Investigation of the thermal stability of Mg/Co periodic multilayers for EUV applications

We present the results of the characterization of Mg/Co periodic multilayers and their thermal stability for the EUV range. The annealing study is performed up to a temperature of 400\degree C. Images obtained by scanning transmission electron microscopy and electron energy loss spectroscopy clearly show the good quality of the multilayer structure. The measurements of the EUV reflectivity around 25 nm (~49 eV) indicate that the reflectivity decreases when the annealing temperature increases above 300\degreeC. X-ray emission spectroscopy is performed to determine the chemical state of the Mg atoms within the Mg/Co multilayer. Nuclear magnetic resonance used to determine the chemical state of the Co atoms and scanning electron microscopy images of cross sections of the Mg/Co multilayers reveal changes in the morphology of the stack from an annealing temperature of 305\degreee;C. This explains the observed reflectivity loss.Comment: Published in Applied Physics A: Materials Science \& Processing Published at http://www.springerlink.com.chimie.gate.inist.fr/content/6v396j6m56771r61/ 21 page

Beam optics issues for the antiproton decelerator

The deceleration of the beam down to 0.1 GeV/c in the ring previously used as Antiproton Collector (AC) at 3.5 GeV/c, requires a number of modifications to the lattice. The insertion of the electron cooling, needed to cool the antiproton beam at low energy, implies the re-arrange-ment of quadrupoles. The optical functions then need to be readjusted in order to keep the large acceptance and to cope with the electron and stochastic cooling environ-ment. Calculations of the linear optics and of the accep-tance are reported. Tests of beam deceleration in the AC show the need for closed-orbit correction at low momentum in addition to the static correction by the movement of the quadrupoles available in the present configuration. The deceleration tests will be discussed and a correction system, which includes trim supplies on the main bending magnets, will be described

Status Report on the Antiproton Decelerator (AD)

CERN's new Antiproton Decelerator (AD) has been delivering a 100 MeV/c antiproton beam to three experiments (ASACUSA, AHENA and ATRAP) since July 10th, 2000. In this status report, we summarise the initial performance of the AD, draw provisional conclusions from the first month of operation and finally give some prospects for the future

Observations on the Red Ratsnake / Cornsnake

This is where the abstract of this record would appear. This is only demonstration data

Hadron Coolers at CERN

To provide efficient deceleration and to produce antiproton beam with the required characteristics two different cooler systems (stochastic and electron) are used in operation on the AD (Antiproton Decelerator) machine. In a near future, an electron cooling system will be used in LEIR (Low Energy Ion Ring) to accumulate ions for LHC. This system will be used for a fast ion beam cooling and stacking. These cooling systems are described

PETAAL Protection of border tree environment and technology

The sycamore lace bug has been identified as one of the main phytosanitary problems for managers of tree-planted heritage sites within green areas in 36,000 French regional authorities. The spread of this pest nationally and the predominance of sycamores in towns makes the bug one of the first pests to receive phytosanitary intervention in our green spaces. The move from chemical control, which is currently used, to biological control is governed by environmental and societal issues and embodies ongoing major technical innovation within green areas