Statistical relation between particle contaminations in ultra pure water and defects generated by process tools

Ultra pure water supplied inside the Fab is used in different tools at different stages of processing. Data of the particles measured in ultra pure water was compared with the defect density on wafers processed on these tools and a statistical relation is found

Characterization of LUSI Mud as Geopolymer Raw Material

The mud of mud volcano samples were collected from an eruption site named ‘LUSI’ (Lumpur “mud” –Sidoarjo), East Java, Indonesia for characterization. Analysis showed that, the major constituents of mud are SiO2 and Al2O3 which are higher than those in fly ash. The particle of mud has a flake-shaped particle and the overall particle size is dominated by particles between 2.5μm – 25.0μm. The results of XRD shows that mud of mud volcano have a characteristic of structurally disordered compounds, and a set of peaks corresponding to minor crystalline phases such as quartz, feldspars, and kaolinite. FTIR adsorption bands of the raw material of mud have the chemical bonding between bands 1-5

Numerical modelling of mud volcanoes and their flows using constraints from the Gulf of Cadiz

It is estimated that the total number of submarine mud volcanoes is between 1000 and 100 000. Because many are associated with greenhouse gases, such as methane, it is argued that the global flux of these gases to the atmosphere from the world’s terrestrial and submarine mud volcanoes is highly significant. Clues to the processes forming submarine mud volcanoes can be found in variations to their height, shape, surface morphology, physical properties and internal structure. A model of isostatic compensation between the mud column and the sediment overlying the mud source is used to predict a depth to the mud reservoir beneath mud volcanoes. Once erupted, the general behaviour of an individual mud flow can be described and predicted using a viscous gravity-current model. The model shows that conical-shaped mud volcanoes comprise multiple, superimposed radial flows in which the thickness, eruption rate and speed of individual mud flows strongly depends on the viscosity, density and over-pressure of the erupted mud. Using these parameters, the model predicts the lowermost flows will be the oldest, thickest and have the greatest length of run-out while the uppermost flows will be the youngest, thinnest and shortest. This model is in contrast to more traditional models of stratiform mud volcano construction in which younger flows progressively bury older ones and travel furthest from the summit. Applying the model to the two mud volcanoes studied in the Gulf of Cadiz, quantitative estimates are derived for the depths to mud sources, exit and flow velocities, eruption duration and volume fluxes, flow thickness and conduit radii. For example, with an average kinematic viscosity of 1.5 m2 s?1 for the erupted mud, a density of 1.8×103 kg m?3 and a thickness for the youngest flows of about 0.5 m, the model predicts a lowermost flow thickness of 3.6 m, an average eruption duration of 7 h and a conduit radius of about 9 m. To construct a conical-shaped mud volcano of 260 m height, similar to those studied in the Gulf of Cadiz, is estimated to require a mud source at 4.6 km depth and a total of at least 100 individually erupted flows

Comparison of compressive strength in mud bricks with shred tires and concrete particles as sustainable materials

Mud bricks consist of clay, water and different materials. Comparing mud bricks to concrete blocks, an evolution in reducing the cost and also in increasing the compressive strength, can be made. A weakness in mud block was shown during the experiments in the absence of additional materials. In consequence, a number of testing took place in mud bricks with different additional materials consisting of shred tires and particles waste concrete. Concrete particles are recycling materials as solid waste that is exported by concrete. To make the mud bricks, in this research different materials were used and concrete particles and shred tires were added in two layers in test boxes. This paper presents the role of different materials in mud brick strength that came as a result of our survey to their effect. The materials used are cheap one because we took them from solid waste and only a little part of them is used in the automotive industry. In this paper has been shown the change in compressive strength under additives materials in mud bricks. As a conclusion performances of mud bricks with shred tires were better than concrete particles

Multiple-antenna-aided OFDM employing genetic-algorithm-assisted minimum bit error rate multiuser detection

The family of minimum bit error rate (MBER) multiuser detectors (MUD) is capable of outperforming the classic minimum mean-squared error (MMSE) MUD in terms of the achievable bit-error rate (BER) owing to directly minimizing the BER cost function. In this paper,wewill invoke genetic algorithms (GAs) for finding the optimum weight vectors of the MBER MUD in the context of multiple-antenna-aided multiuser orthogonal frequency division multiplexing (OFDM) .We will also show that the MBER MUD is capable of supporting more users than the number of receiver antennas available, while outperforming the MMSE MUD

Mobilisation of arsenic from bauxite residue (red mud) affected soils: effect of pH and redox conditions

The tailings dam breach at the Ajka alumina plant, western Hungary in 2010 introduced ~1 million m3 of red mud suspension into the surrounding area. Red mud (fine fraction bauxite residue) has a characteristically alkaline pH and contains several potentially toxic elements, including arsenic. Aerobic and anaerobic batch experiments were prepared using soils from near Ajka in order to investigate the effects of red mud addition on soil biogeochemistry and arsenic mobility in soil–water experiments representative of land affected by the red mud spill. XAS analysis showed that As was present in the red mud as As(V) in the form of arsenate. The remobilisation of red mud associated arsenate was highly pH dependent and the addition of phosphate to red mud suspensions greatly enhanced As release to solution. In aerobic batch experiments, where red mud was mixed with soils, As release to solution was highly dependent on pH. Carbonation of these alkaline solutions by dissolution of atmospheric CO2 reduced pH, which resulted in a decrease of aqueous As concentrations over time. However, this did not result in complete removal of aqueous As in any of the experiments. Carbonation did not occur in anaerobic experiments and pH remained high. Aqueous As concentrations initially increased in all the anaerobic red mud amended experiments, and then remained relatively constant as the systems became more reducing, both XANES and HPLC–ICP-MS showed that no As reduction processes occurred and that only As(V) species were present. These experiments show that there is the potential for increased As mobility in soil–water systems affected by red mud addition under both aerobic and anaerobic conditions

Acoustic Scattering from Mud Volcanoes and Carbonate Mounts

Submarine mud volcanoes occur in many parts of the world’s oceans and form an aperture for gas and fluidized mud emission from within the earth’s crust. Their characteristics are of considerable interest to the geology, geophysics, geochemistry, and underwater acoustics communities. For the latter, mud volcanoes are of interest in part because they pose a potential source of clutter for active sonar. Close-range (single-interaction) scattering measurements from a mud volcano in the Straits of Sicily show scattering10–15dB above the background. Three hypotheses were examined concerning the scattering mechanism: (1) gas entrained in sediment at/near mud volcano, (2) gas bubbles and/or particulates (emitted) in the water column, (3) the carbonate bio-construction covering the mud volcano edifice. The experimental evidence, including visual, acoustic, and nonacoustic sensors, rules out the second hypothesis (at least during the observation time) and suggests that, for this particular mud volcano the dominant mechanism is associated with carbonate chimneys on the mud volcano. In terms of scattering levels, target strengths of 4–14dB were observed from 800to3600Hz for a monostatic geometry with grazing angles of 3–5°. Similar target strengths were measured for vertically bistatic paths with incident and scattered grazing angles of 3–5° and 33–50°, respectively

Simulated annealing based multiuser detection for synchronous SDMA system

In this treatise, a novel Simulated Annealing (SA) based Multi-User Detection (MUD) is proposed in synchronous Space Division Multiple Access (SDMA) system. SA MUD modifies experiential Cooling Schedule (CS) of traditional SA algorithm according to its use in MUD. Moreover, in order to ensure sufficient diversity acquired in the whole Markov chain and to prevent from being trapped at local optima, Uniform Mutation (UM) based trial vector generation scheme is brought forward. In addition, the optimal solution recording scheme is also invoked in case of being lost during cooling process. Simulation results illustrate that in comparison with Genetic Algorithm (GA) MUD in the same simulation conditions, without turbo processing and soft-information, SA MUD proposed in this paper performs better, approaching the performance of Maximum Likelihood (ML) MUD and imposes lower complexity

Impact of Channel Estimation Errors on Multiuser Detection via the Replica Method

For practical wireless DS-CDMA systems, channel estimation is imperfect due to noise and interference. In this paper, the impact of channel estimation errors on multiuser detection (MUD) is analyzed under the framework of the replica method. System performance is obtained in the large system limit for optimal MUD, linear MUD and turbo MUD, and is validated by numerical results for finite systems.Comment: To appear in the EURASIP Journal on Wireless Communication and Networking - Special Issue on Advanced Signal Processing Algorithms for Wireless Communication

Ant-Colony-Based Multiuser Detection for MC DS-CDMA Systems

In this contribution we present a novel ant colony optimization (ACO) based multi-user detector (MUD) designed for synchronous multi-carrier direct sequence code division multiple access (MC DSCDMA) systems. The operation of the ACO-based MUD is based on the behaviour of the ant colony in nature. The ACO-based MUD aims for achieving the same bit-error-rate (BER) performance as the optimum maximum likelihood (ML) MUD, without carrying out an exhaustive search of the entire MC DS-CDMA search space constituted by all possible combinations of the received multi-user vectors. We will demonstrate that the system is capable of supporting almost as many users as the number of chips in the spreading sequence, while searching only a small fraction of the entire ML search space. It will also be demonstrated that the number of floating point operations per second is a factor of 108 lower for the proposed ACO-based MUD than that of the ML MUD, when supporting K = 32 users in a MC DS-CDMA system employing 31-chip Gold codes as the T-domain spreading sequence