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The term "sediment" refers to the tiny particles of rocks and other materials that sink to the ocean floor and eventually settle and accumulate on the bottom. All regions of the seafloor contain some form of sediment, although there are many different types of sediments from a variety of sources, and the amount of accumulated sediment can vary greatly from place to place. These areas include regions near the mouths of rivers where there is high sediment discharge, and passive margins near the continents where the seafloor has had millions of years for sediment to accumulate. On the other hand, sediments are sparse along divergent plate boundaries where new oceanic crust is being formed, as the crust is too new for significant accumulation and in the central oceans that are far away from any significant sediment sources. Rates of sediment accumulation are relatively slow throughout most of the ocean, in many cases taking thousands of years for any significant deposits to form. Sediment transported from the land accumulates the fastest, on the order of one metre or more per thousand years for coarser particles. Sediments from the land are deposited on the continental margins by surface runoff, river discharge, and other processes. Turbidity currents can transport this sediment down the continental slope to the deep ocean floor. [ABSTRACT FROM AUTHOR]

Banyumas basin is one of sedimentary basin in Central Java. Based on surface geological mapping we can found many turbidite sediment in this area. Turbidite sediment is a sedimentary rocks with certain sedimentary structure such as graded bedding, paralel lamination, cross lamination or wavy lamination. Turbidite sediment formed by turbidity current which is caused by the existing of a slope. Several depositional environment which is have a slope can be a candidate as depositional environment of turbidite sediment in Banyumas Basin. Previous researcher always refer it to submarine fan depositional environment, because it is believed that Banyumas is a deep marine in the past time. But in the recent research, we found a buried volcanic arc in the middle of Banyumas Basin, that means there are several volcano formed at the middle of sea in the past time. Turbidity current cause by the slope of volcano’s flank not the submarine slope. So the new paradigm to understanding the turbidite sediment in Banyumas Basin is Flysch and molasse turbidite sediment. Flysch is a turbidite sediment related to an orogenic process or the birth of a volcano, and molasse is a turbidite sediment related to reworked process of a volcano, such as weathering, erosion, transportation and then resedimentation. [ABSTRACT FROM AUTHOR]

Fans are such simple and common equipment, that we tend to underestimate their importance, giving them our attention only when their performances are not meeting our criteria. General mechanical ventilation is typically carried out by two co-operating installations: one for the inlet of fresh air into the room or technological space, and the second for absorbing the vicious air. Both fresh air and the evacuation of the air, the fans must be equipped with a diffuser. When the fan blows freely into the atmosphere without any connection, a loss equivalent to 50% of the medium dynamic pressure at the discharge mouth occurs. If the fan blows in a diffuser, the loss depends on its angle. At an angle at the diffuser’s top of 30º corresponds a loss of ≈ 25% of the medium dynamic pressure in the discharge mouth. To reduce air vortices, the diffusers must be built at an angle of inclination to vertical or horizontal between 12-15 °, in order to reduce the aerodynamic resistances. These considerations are sufficient to ensure the proper functioning of industrial ventilation facilities. In the paper there will be presented the distribution of velocity fields of an axial fan placed on a circular pipeline and provided on the air discharge side with a 1.5 m long diffuser at a tilt angle to vertical or horizontal of 12º. [ABSTRACT FROM AUTHOR]

In the northwestern Black Sea the Danube deep sea fan has an extent of over 150 km and stretches from several hundred meters water depth down to the abyssal plain at 2200 m water depth. This large turbiditic system comprises a series of channel-levee systems, with deposits of mass transport. Its evolution was due to the fluctuations of sea level and sediment inputs. Sedimentary and seismic facies identified on the Danube deep sea fan are similar to those that characterize most fans of this type. In the study area was identified typical deep-water depositional sequences consisting of debris flow deposits overlain by sandy deposits of frontal splay, channel fill deposits, leveed-channel deposits, and finally fallowed by condensed sections - according to model proposed by Posamentier and Koola (2003)[7] from other studies made by Weimer (1991), Piper et al. (1997) [5], Pirmez et al. (1997) [6], Manley and Flood (1998) [3], Maslin et al. (1998) [4], Beauboeuf and Friedmann (2000) [1], Brami et al. (2000) [2], and Winker and Booth (2000)) [8]. In this paper we analyzed the mass transport facies distribution in the study area and determined the thickness values. This is possible following 95 seismic profiles which extend between 1000 m and 1750 m water depth. We identified, delineated and analyzed on the seismic sections the deep-water deposits on the Danube submarine fan and, based on interpretation and correlation of seismic horizons, we could estimate the values of sedimentary facies thickness on the izochrone and thickness maps using the software Petrel and applying seismo-stratigraphic method. The sequence boundaries marked on seismic profiles are available in two-way travel time TWT (ms. Mass transport deposits (MTD) appears to be a predominant process for deposition in the submarine environment. MTD occur in the Danube submarine fan where mass wasting is due to sediment instability on the upper slope because of the large influx of unconsolidated material and the high slope gradients. The channel-levee systems are intercalated with commonly structureless reflective bodies interpreted as mass-transport deposits, including slides, slumps and debris-flows (H.K.Wong et al.,1994). Like the other systems of this type (Amazon fan, Missisippi fan or Indus fan) the Danube fan consists of stacked channel-levee system intercalated with mass-transport deposits. [ABSTRACT FROM AUTHOR]

In the northwestern Black Sea the Danube deep sea fan has an extent of over 150 km and stretches from several hundred meters water depth down to the abisal plain at 2,200 m water depth. The most recent channel-levee system is connected to the Viteaz Canyon, wich is deeply (500 m) incised into the shelf with the head at about 24 km landward of the shelf edge. Viteaz Canyon is 2.4 to 4 km wide, trending northwest-southeast, with stepped flanks and meandering erosional V-shaped thalveg, slightly sinous and unleeved valley. At about 800 m water depth, the upper slope canyon changes into a large single-leveed channel - Danube submarine channel -- that is feeding a deep water fan. The channel is 2.4 km wide (between the top of the levees) and 270 m deep between the channel floor and the top of the levees, measured at about 1200 m water depth. Below 1400 m water depth, the fan morphology is modified by the bifurcation of this single channel and a new meandering channel on NW-SE direction. In this study we propose to estimate the thickness variation of seismic facies that supports changes in the bifurcation area of the Danube submarine channel. This is possible following the seismic sections proposed for study, defining the main sedimentary facies and get morphological and thickness maps using the software Petrel and applying seismo-stratigraphic method. We will analyze the initiation of new channel NW-SE direction on the seismic sections and thickness and morphologic obtained maps. [ABSTRACT FROM AUTHOR]