Characterisation of Soft Soil Microstructure Stabilised With Binary Blending Using Two Waste Fly Ashes

This paper represents an investigation on the microstructures of soil stabilised with binary blending using two different types of waste fly ashes. The microanalysis was conducted in order to realise the improvement in the strength of the stabilised soil. The soil used in this study was an intermediate plasticity silty clayey soil with medium organic matter content. FA1 was optimised in a previous study dependant on the unconfined compression strength (UCS) test conducted on specimens of soil treated with various percentages of FA1. The optimum percentage of FA1 was 12% of the dry weight of the soil. In this study, UCS test was conducted on specimens of soft soil treated with 12% of binder produced by binary blending of FA1 and FA2 with different proportions and the specimens were kept for curing at different periods (3, 7, 14, and 28 days) prior to being subjected to UCS testing. Scanning electronic microscopy (SEM) testing was employed to investigate the mechanism of strength improvement in the most remarkable soil-binder mixture. The results showed a significant development in stabilised soil strength. Moreover, the bond building sequences and subsequent changes in the microstructures of the stabilised soil due to the chemical reaction of the added fly ashes were observed

Formal Scenario Definition Language for Aviation: Aircraft Landing Case Study

Although the importance of scenarios in modeling and simulation has long been well known, there still exists a lack of common understanding and standardized practices in simulation scenario development. This paper proposes a Domain-Specific Language (DLS) to provide a standard scenario specification that will lead to a common mechanism for verifying and executing aviation scenarios, effective sharing of scenarios among various simulation environments, improve the consistency among different simulators and simulations, and even enable the reuse of scenario specifications. Following DSL design practices, the proposed Aviation Scenario Definition Language (ASDL) will provide a well-structured definition language to formally specify complete aircraft landing scenarios. In order to capture the necessary constructs for a simulation scenario, Simulation Interoperability Standards Organization (SISO) Base Object Model (BOM) is adopted as the baseline metamodel. This baseline is extended using the fundamentals of aircraft landing that cover all the domain-related concepts and terminology as constructs. By taking a formal approach in defining aviation scenarios, ASDL aims at providing consistency and completeness checking, and model-to-text transformations capabilities for various targets in the aviation scenario definition domain. The results of this work will be used to develop a graphical modeling environment and automatic means to transform scenario models into executable scenario scripts. The work presented here is the first stepping stone in formal scenario definition in aviation domain

The Characterisation of the Strength Development of A Cement-Stabilised Soft Soil Treated with Two Different Types of Fly Ashes

There are several problems associated with soft soils such as the low strength, high compressibility and the sensitivity with the changes in the water content. In order to mitigate such undesirable properties, soft soils are often improved and stabilised either mechanically chemically. However, chemical stabilisation is the most effective technique to improve the geotechnical properties of the soft soil. This study aims to improve the properties of a soft soil regarding the consistency and compressive strength by using a small amount of cement (5% OPC by the dry weight of the treated soil). Then two different types of fly ash were examined for pozzolanic activation of the cement treated soil. These fly ashes were pulverised fuel ash (PFA) and palm oil fuel ash (POFA). Initially, trial specimens containing 5% OPC with 5% of PFA or POFA were prepared for unconfined compressive strength testing (UCS) conducted at 7 days of curing. These trial specimens were manufactured to indicate with which type of fly ash the future research should be based on. The results of UCS test revealed that PFA indicated higher strength than that for POFA after 7 days of curing. Thus PFA was considered in this study as a pozzolanic activator for further experimental works. Additionally, the cement-stabilised soil (CSS) mixture was mixed with PFA with different proportions where OPC was kept as 5% and PFA was varied from 5–15% by the dry weight of the stabilised soil. The improvement levels in the stabilised soil were evaluated dependent on the results of UCS test conducted on specimens of CSS treated with different percentages of PFA and subjected to two different periods of curing (7 and 28 days). The effect of PFA on the compaction parameters (maximum dry density (MDD), optimum moisture content (OMC)) and Atterberg limits (liquid limit (LL), plastic limit (PL), along with the plasticity index (PI)) of the CSS soil was also explored in this study. The plasticity characteristic of the treated soil was found to decrease with continuous increments of PFA. The PI decreased from 20.3 for the untreated soil to 13.75 for the cement stabilised soil treated with 10% PFA. The optimised mixture in this research was found to be (soil + 5% OPC + 10% PFA) which increased the UCS of the soil from 134kPa for the virgin soil (VS) and 732kPa for the soil treated with only 5% OPC cured for 28 days to 946kPa at an equivalent 28 days of curing

A study of the RF characteristics for wireless sensor deployment in building environment

In this paper, The radio Frequency (RF) Monitoring and Measurement of the Environmental Research Institute (ERI) located in Cork city will be monitored and analyzed in both the Zigbee (2.44 GHz) and the industrial, scientific and medical (ISM 433 MHz). The main objective of this survey is to confirm what the noise and interferences threat signals exist in these bands. It was agreed that the surveys would be carried out in 5 different rooms and areas that are candidates for the Wireless Sensors deployments. Based on the carried on study, A Zigbee standard Wireless Sensor Network (WSN) will be developed employing a number of motes for sensing number of signals like temperature, light and humidity beside the RSSI and battery voltage monitoring. Such system will be used later on to control and improve indoor building climate at reduced costs, remove the need for cabling and both installation and operational costs are significantly reduced

Developing wireless measurement system for building deployed capacitive sensors with optimized RF front end circuit

In this paper, a prototype of miniaturized, low power, bi-directional wireless sensor node for wireless sensor networks (WSN) was designed for doors and windows building monitoring. The capacitive pressure sensors have been developed particularly for such application, where packaging size and minimization of the power requirements of the sensors are the major drivers. The capacitive pressure sensors have been fabricated using a 2.4 mum thick strain compensated heavily boron doped SiGeB diaphragm is presented. In order to integrate the sensors with the wireless module, the sensor dice was wire bonded onto TO package using chip on board (COB) technology. The telemetric link and its capabilities to send information for longer range have been significantly improved using a new design and optimization process. The simulation tool employed for this work was the Designerreg tool from Ansoft Corporation

Soft Soil Stabilisation Using High Calcium Waste Material Ash

Civil engineering projects located in areas with soft soil present some of the most common problems in many parts of the world. Depending on the nature of the project, expensive solutions are sometimes used, which commonly involves the removal and replacement of the weak soils. Alternatively, ground improvement is now considered the best solution for such problems. Soil improvement can be achieved either by mechanical and/or chemical stabilisation. To reduce the use of cement and lime as the most traditional stabilizers applied to soft soils, sustainable waste materials have been increasingly used for soil stabilisation. This paper presents the results of a laboratory study on the stabilisation of silty clayey soil using a waste material fly ash (FA) with high calcium content produced from the incineration processes in domestic power stations. The FA used in this study has a high content of calcium oxide CaO and suitable content of silicon dioxide SiO2 (more than 25%). These cementitious and pozzolanic properties are responsible for the self-cementing characteristics of this fly ash. An intermediate plasticity silty clayey soil with medium organic matter content has been used in this study. The effect of FA on the physical and engineering properties on the selected soil such as the consistency limits, compaction characteristics (optimum moisture content and maximum dry density), and soil strength (unconfined compressive strength (UCS)), has been investigated. Different percentages of fly ash were added to the soft soil (1.5, 3, 6, 9, 12, and 15%) to produce different admixtures. Improvement levels were evaluated dependant on the UCS tests carried out on specimens at different periods of curing (zero, 7, 14, and 28 days). Results indicated that the maximum dry density decreased and the optimum moisture content increased with the increase of the FA content. In terms of the UCS tests, the results yielded the optimum value of the FA used in this study to be 12.0%, as this percentage decreased the index of plasticity (IP) significantly. The results of this study indicated that the use of this waste material could produce a significant cementitious reaction when added to the soil, and it could be used as a supplementary cementitious material

Design of miniaturized wireless sensor mote and actuator for building monitoring and control

In this paper, a wireless sensor network mote hardware design and implementation are introduced for building deployment application. The core of the mote design is based on the 8 bit AVR microcontroller, Atmega1281 and 2.4 GHz wireless communication chip, CC2420. The module PCB fabrication is using the stackable technology providing powerful configuration capability. Three main layers of size 25 mm2 are structured to form the mote; these are RF, sensor and power layers. The sensors were selected carefully to meet both the building monitoring and design requirements. Beside the sensing capability, actuation and interfacing to external meters/sensors are provided to perform different management control and data recording tasks. Experiments show that the developed mote works effectively in giving stable data acquisition and owns good communication and power performance

The Estimated of Boron Concentration in Water Samples of the north of Basrah Governorates Using AAS Techniques

Significant risks for human health may results from exposure to non pathogenic toxic contaminants that are often globally ubiquitous in waters from which drinking water is derived to measure the Boron, 105B concentration in water samples in Basra governorate in north of Iraq. The measurements were performed by analyzing the water samples collected from 55 location using AAS Technique. The Boron concentrations which are obtained ranged from 0.1185 ppm in Alhwair - Al-Samayd to 1.539 ppm in Hawair- Harde river in water samples. The results are presented and compared with other studies. The results could be utilized to make distinctive supplementary contributions when contam- ination event occurs and to implement water quality standards by concerned authorities to maintain radioactive contamination-free drinking water supplies for the people. The study further reveals that 55 surface water samples have boron below detection limit. The presence of boron in drinking water sources in this territory is of natural origin. Thus, there is possibility of severe pollution problem with boron in near future.nbs

Removal of Nitrogen Compounds from Industrial Wastewater Using Sequencing Batch Reactor: The Effects of React Time

This study was performed to optimise the react time (RT) and study its effects on the removal rates of nitrogen compounds in a sequencing batch reactor (SBR) treating synthetic industrial wastewater. The results showed that increasing the RT from 4 h to 10, 16 and 22 h significantly improved the nitrogen compounds’ removal efficiency, it was increased from 69.5% to 95%, 75.7 to 97% and from 54.2 to 80.1% for NH3-N, NO3-N and NO2-N respectively. The results obtained from this study showed that the RT of 22 h was the optimum for nitrogen compounds removal efficiency