Analisa Kehilangan Muatan (Cargo) Petroleum Oil Saat Discharging Pada Kapal Tanker MT. Longhung 5 Anchorage Ambon

Kehilangan mauatan adalah permasalahan yang sering terjadi saat kapal selesai melakukan pemuatan atau pembongkaran. Kapal MT. Longhung 5 merupakan kapal charter yang bertujuan untuk pengangkutan bahan bakar jenis FO CST 380 MAX 2%S yang digunakan sebagai bahan bakar utama kapal pembangkit listik MVPP (Marine Vessel Power Plant) Yasin Bey di PLTU Wai. Proses pengangkutan muatan yaitu MT. Longhung melakukan OB (Operation Bunker) dengan STK Merlion 121 di Tulehu anchorage. Permasalahan yang terjadi yaitu dimana hasil perhitungan melewati batas toleransi 0,5% dai nilai Bill of Loading. Tujuan dari penelitian ini adalah untukmengetahui besar kehilangan volume muatan saat discharging dari kapal MT. Longhung 5 terhadap kapal STK Merlion 121. Penelitian ini menggunakan metode pendekatan dengan analisis kuantitatif yaitu mengamati langsung terhadap objek yang diteliti kemudian melakukan perhitungan sesusi data, rumus dan mengolah data tersebt menggunakan Microsoft Exel. Variabel terikat penelitian ini yaitu temperatur, trim dan muatan. Variabel bebasnya adalah volume kehilangan saat discharging . Hasil perhitungan Gross Standard Volume before discharging sebesar 8.361,166 mt. Hasil Gross Standard Volume after discharging (ROB) sebesar 3.479,930 mt. Sehingga total cargo dischare sebesar 4.881,236 mt. Sedangkan jumlah muatan yang diterima STK Merlion sebesar 4.821,526 mt dengan pengukuran menggunakan Flowmeter. Sehingga volume kehilanan sebesar 59,710 mt dengan percentage difference 1,22%. Karena telah melewati batas toleransi sehingga dibuat Letter of Protest Discrepancy sehingga volume kehilangan 33,54 mt dengan percentage difference 0,69%. Kemudian untuk perusahaan atau Notice of Apparent Discrepancy nilai kehilangan 24,232 mt dengan percentage difference 0,5% sesuai dengan toleransi. Kehilangan muatan disebabkan karena tabel kalibrasi kapal yang sudah tidak sesuai dengan standard, alat ukur yang belum dikalibrasi, pada saat sounding tidak akurat sampai dasar tanki dan adanya air dan sediment pada dasar tanki kapal

Performance optimization and load-balancing modeling for superparametrization by 3D LES

In order to eliminate climate uncertainty w.r.t. cloud and convection parametrizations, superpramaterization (SP) [1] has emerged as one of the possible ways forward. We have implemented (regional) superparametrization of the ECMWF weather model OpenIFS [2] by cloud-resolving, three-dimensional large-eddy simulations. This setup, described in [3], contains a two-way coupling between a global meteorological model that resolves large-scale dynamics, with many local instances of the Dutch Atmospheric Large Eddy Simulation (DALES) [4], resolving cloud and boundary layer physics. The model is currently prohibitively expensive to run over climate or even seasonal time scales, and a global SP requires the allocation of millions of cores. In this paper, we study the performance and scaling behavior of the LES models and the coupling code and present our implemented optimizations. We mimic the observed load imbalance with a simple performance model and present strategies to improve hardware utilization in order to assess the feasibility of a world-covering superparametrization. We conclude that (quasi-)dynamical load-balancing can significantly reduce the runtime for such large-scale systems with wide variability in LES time-stepping speeds

Exploring Community Preparedness for Complex Disaster: A Case Study in Cilegon (Banten Province in Indonesia)

This study aims at examining how local communities in City of Cilegon (Banten province in Indonesia) consider ‘complex disasters’, and clarifying their subjective perceptions. The present research is considered as the first step in our comprehensive research design beyond a specific case study. The nuclear accidents in the GreatEast Japan Earthquake and the huge flood in Thailand provide lessons that natural disasters can cause catastrophic influences on industries and they generate cascading effects and damages. We define such complicated phenomena as ‘complex disasters’ in this article. Cilegon is potentially exposed to such complex disasters because it has natural disaster risks (among others, the Krakatau volcano sits adjacent to it, andrecalling historical earthquakes and tsunami) and industrial disaster risks (a lot of heavy industry facilities including chemical ones), and these two types of risks can be combined and made reality. A ‘model for the communication of risk’ developed by Rodriguez et al. (2007) is adopted as an analytical framework in this study. The model predicts involvement of many types of actors and can be considered as an adequate framework for our study. This study mainly focused on one industrial gas facility of Pertamina, a state-owned energy company, and its surrounding community (Lebak Gede village) in Cilegon. The qualitative methodologies were used in this study: One focused group discussion (FGD) and three key informant interviews were implemented by the authors. The participants of the FGD were twelve leaders of the neighborhood associations (locally described as ‘RT’ and ‘RW’ in Indonesian acronym) closest to the Pertamina facility (two RW leaders and ten RT leaders). The key informant interviews were separately and additionally conducted with a head of a village, a neighborhoodassociation leader (this leader was different from the FGD participants) and a local forum entity, in order to reinforce observations at the FGD. Our survey observed that involvement of the Indonesia Power, a subsidiary of state-owned electricity company whose facilities adjacent to Petamina’s facility, as one of the industry actors, local governmental agencies and the Indonesian Red Cross. On the other hand, we did not clearly identify any clear involvement of the educational institutions and the mass media, although the model of Rodriguez et al. (2007) estimates their engagement. People in Lebak Gede village have already expected potential threats by large-scale natural disasters. Furthermore, they recognize that such disasters give influence on the industrial facilities and the consequences are catastrophic. Although local residents in Lebak Gede village had a lot of experiences of industrial accidents in the past, these experiences did not initiate a significant mindset change for a more organized preparedness. Instead, they paid larger attentions to floods as their preparedness priority. This study adopted the qualitative method for gathering specific information, but more comprehensive research can contribute to verify preparedness and risk perception on the complex disasters. Although this article selectively dealt with one village (Lebak Gede village) and its preparedness and perception, the findings is to be further clarified in detail for generalizing community preparedness for the complex disasters. Keywords: community, risk perception, natural disaster risk, industrial disaster risk, complex disaster, Cilego

The Effects of X-Ray Feedback from AGN on Host Galaxy Evolution

Hydrodynamic simulations of galaxies with active galactic nuclei (AGN) have typically employed feedback that is purely local: i.e., an injection of energy to the immediate neighborhood of the black hole. We perform GADGET-2 simulations of massive elliptical galaxies with an additional feedback component: an observationally calibrated X-ray radiation field which emanates from the black hole and heats gas out to large radii from the galaxy center. We find that including the heating and radiation pressure associated with this X-ray flux in our simulations enhances the effects which are commonly reported from AGN feedback. This new feedback model is twice as effective as traditional feedback at suppressing star formation, produces 3 times less star formation in the last 6 Gyr, and modestly lowers the final BH mass (30%). It is also significantly more effective than an X-ray background in reducing the number of satellite galaxies.Comment: 9 emulateapj pages, 8 figures; accepted to Ap

Efficiency of the dynamical mechanism

The most extreme starbursts occur in galaxy mergers, and it is now acknowledged that dynamical triggering has a primary importance in star formation. This triggering is due partly to the enhanced velocity dispersion provided by gravitational instabilities, such as density waves and bars, but mainly to the radial gas flows they drive, allowing large amounts of gas to condense towards nuclear regions in a small time scale. Numerical simulations with several gas phases, taking into account the feedback to regulate star formation, have explored the various processes, using recipes like the Schmidt law, moderated by the gas instability criterion. May be the most fundamental parameter in starbursts is the availability of gas: this sheds light on the amount of external gas accretion in galaxy evolution. The detailed mechanisms governing gas infall in the inner parts of galaxy disks are discussed.Comment: 6 pages, 3 figures, to be published in "Starbursts - From 30 Doradus to Lyman break galaxies", ed. R. de Grijs and R. Gonzalez-Delgad

Automated detection of filaments in the large scale structure of the universe

We present a new method to identify large scale filaments and apply it to a cosmological simulation. Using positions of haloes above a given mass as node tracers, we look for filaments between them using the positions and masses of all the remaining dark-matter haloes. In order to detect a filament, the first step consists in the construction of a backbone linking two nodes, which is given by a skeleton-like path connecting the highest local dark matter (DM) density traced by non-node haloes. The filament quality is defined by a density and gap parameters characterising its skeleton, and filament members are selected by their binding energy in the plane perpendicular to the filament. This membership condition is associated to characteristic orbital times; however if one assumes a fixed orbital timescale for all the filaments, the resulting filament properties show only marginal changes, indicating that the use of dynamical information is not critical for the method. We test the method in the simulation using massive haloes($M>10^{14}$h$^{-1}M_{\odot}$) as filament nodes. The main properties of the resulting high-quality filaments (which corresponds to $\simeq33$ of the detected filaments) are, i) their lengths cover a wide range of values of up to $150$h$^{-1}$Mpc, but are mostly concentrated below 50h$^{-1}$Mpc; ii) their distribution of thickness peaks at $d=3.0$h$^{-1}$Mpc and increases slightly with the filament length; iii) their nodes are connected on average to $1.87\pm0.18$ filaments for $\simeq 10^{14.1}M_{\odot}$ nodes; this number increases with the node mass to $\simeq 2.49\pm0.28$ filaments for $\simeq 10^{14.9}M_{\odot}$ nodes.Comment: 17 pages, 13 figures, MNRAS Accepte