Showing papers in "Cogent engineering in 2017"

A review on automated pavement distress detection methods

Abstract: In recent years, extensive research has been conducted on pavement distress detection. A large part of these studies applied automated methods to capture different distresses. In this paper, a literature review on the distresses and related detection methods are presented. This review also includes commercial solutions. Thereafter, a gap analysis is conducted which is concluded that in particular the distresses related to pavement micro-texture need serious additional research in order to be implemented in a cost-effective fashion. Depth-related distresses are detectible fairly well, but rely on expensive tools.

Causes of delay in residential construction projects in Cambodia

Abstract: Construction industry is one of the significant contributors to the economic growth and development of Cambodia. Two major challenges are limiting the performance of the construction industry in Ca...

MIL and SIL and PIL tests for MPPT algorithm

Abstract: This paper presents guidelines to develop the Maximum Power Point Tracking controller, as developed in the automotive and aeronautical applications, this by following the V-cycle development process, which means that our controller will be validated by using Model In the Loop/ Software In the Loop/Processor In the Loop tests. In order to have the possibility of integrating the MPPT embedded software in automotive and aeronautical areas, and on the other hand to propose a low-cost option to test the hardware implementation of the MPPT algorithm. Therefore, a modified variable step Incremental Conductance algorithm is proposed in this study, which can reduce the steady-state oscillations and increase the tracking speed under sudden irradiance variation. Then, the Model-based design of the modified algorithm is developed and connected to the plant model (photovoltaic panel and Boost converter). Next, the system model is tested and validated by using Model In the Loop process. After that, the software...

User experience framework that combines aspects, dimensions, and measurement methods

Abstract: Successful software products necessitate users’ satisfaction when experiencing the use of the software. This is not only determined by the software functionalities and completeness, but als...

Moth flame optimization to solve optimal power flow with non-parametric statistical evaluation validation

Abstract: This article demonstrates an appositeness of a novel metaheuristic optimization algorithm viz. the moth flame optimization (MFO) to solve various non-convex, non-linear optimum power flow (OPF) objective functions. MFO is based on movement of moths with respect to the source of light. In this paper, five single objective functions are selected for solving the OPF problem: generator fuel cost minimization under various realistic conditions, real power loss reduction, and emission minimization. Simulations are performed on the IEEE 30-bus system to identify efficacy of the proposed method. Results obtained by MFO are collated with other stochastic methods reported in literature. Comparison reflects that MFO obtains optimum value with rapid and smooth convergence. Statistical tests like Wilcoxon test, Quade test, Friedman test and Friedman aligned test are also carried out to check the effectiveness of the MFO. Comparison of MFO with other stochastic algorithms demonstrates superiority of MFO in term...

Design and analysis of solar PV-fuel cell and wind energy based microgrid system for power quality improvement

Abstract: In recent years the electric energy sector has been experiencing an extension into distributed generation, and in this context microgrids have been achieving increasing importance. Microgrids are c...

Corrosion polarization behavior and microstructural analysis of AA1070 aluminium silicon carbide matrix composites in acid chloride concentrations

Abstract: The effect of SiC content and NaCl concentration on the corrosion resistance of AA1070 aluminium in 2 M H2SO4 was evaluated with potentiodynamic polarization technique, open circuit potential measurement (OCP) and optical microscopy. Results showed SiC increased the corrosion susceptibility of the alloy at lower NaCl concentrations compared to results obtained at 0% NaCl which showed significant decrease in corrosion rates, with maximum inhibition efficiency of 90.84% at 20% SiC content. The corrosion rates decreased at higher NaCl concentration,with maximum inhibition efficiency of 94.12 and 77.27% at 20% SiC. Alloy samples in 2 M H2SO4/0% NaCl at 0 and 20% SiC visibly decreased in OCP value over wide variation compared to samples with varying NaCl concentration due to loss of passivity. OCP values for alloys at varying NaCl concentration decreased over a very short variation due to repassivation. Statistical data showed silicon carbide to be the only relevant variable responsible for the corrosion rate values with F-values of 8.85 corresponding to a percentage significance of 54.8%. Optical images showed the presence of corrosion pits of smaller dimension, yet deeper on the morphology of the alloy without silicon carbide compared the alloy containing it, whose corrosion pits, seems wider but very shallow

Design and implementation of an efficient FIR digital filter

Abstract: Digital signal processing (DSP) circuits are extremely important in computing and communications areas One application of DSP is a Finite impulse response (FIR) filter The principle objective of this exploration is to present a methodology for an upgraded framework of a FIR digital filter from software level to the hardware level It includes the selection of design method, structure and cost effective hardware utilization Theoretical and experimental results performed FIR band pass filter suggests that the window design method is relatively simple and easy to use because of the availability of well-defined equation Comparison presented that Kaiser window gives the minimum main-lobe width and a sharp cut-off which means this window has less transition width and the study showed that the Direct-Form structure approach is simpler and offers a better performance than other common filter structures It results in low cost, reduced area and more robust to withstand the quantization errors For effi

Application of waste tyre-based activated carbon for the removal of heavy metals in wastewater

Abstract: This study presents the preparation and characterization of chemically activated carbonaceous materials obtained from waste tyres and the prepared adsorbent was applied for the adsorptive removal of Cd(II) and Pb(II) in the domestic wastewater samples. The activation efficiency of phosphoric acid (H3PO4) and hydrogen peroxide (H2O2) were evaluated and H2O2 was chosen as the appropriate activating agent as compared to phosphoric acid. The developed adsorbent was characterized using the scanning electron microscope (SEM), Brunnuer Emmet Teller (BET) which helped to decide which adsorbent material is best in terms of the surface area and Fourier transform infrared spectroscopy (FT-IR). Two-level fractional factorial design was used for the optimization of parameters affecting the adsorptive removal of Cd(II) and Pb(II). The optimum conditions were found to be 6.5, 0.2 g, 32.5 min and 55 mg L−1, for sample pH, mass of adsorbent, contact time and initial concentration, respectively. Amongst every adsor...

Effect of glass powder on the compression strength and the workability of concrete

Abstract: Several studies have been made to examine the potential mineralogical and mechanical properties of glass aiming to improve the characteristic properties of concrete where glass has been used in var...

Comparative study of the use of natural and artificial coagulants for the treatment of sullage (domestic wastewater)

Abstract: This work presented a comparative study of the effectiveness of natural coagulant (Moringa oleifera and hydrolyzed cassava) extracts and artificial coagulant (alum) as primary coagulants for sullag...

Design and analysis of CPW based shunt capacitive RF MEMS switch

Abstract: This paper is about, the design and analysis of shunt capacitive RF MEMS switch with less actuation voltage, low insertion losses and high isolation losses. The switch design is incorporated the El...

Comparative performances evaluation of FACTS devices on AGC with diverse sources of energy generation and SMES

Abstract: This paper deals with automatic generation control of multi area power system using a Fuzzy PID controller. The controller parameters are optimized by Grey Wolf Optimizer (GWO) algorithm. Initially, Hydro-Thermal-Gas two area power systems is considered and superiority of the proposed controller is verified by comparing the results with GWO optimized classical PID controller as well as recently published optimal controller, such as DE-PID and TLBO-PID controllers. The proposed methodology is also verified with a modified power system with a nuclear plant and HVDC link and reveals better performance when compared with sliding mode controller tuned by TLBO algorithm. The proposed controller is designed to stabilize the frequency deviations of nonlinear power system considering FACTS devices and SMES. The results reveal that IPFC seems to be a promising alternative for frequency and tie-line power stabilization. Also the proposed controller is robust and satisfactory towards random step and sinusoida...

A micro level electrostatically actuated cantilever and metal contact based series RF MEMS switch for multi-band applications

Abstract: In this paper, a micro level electrostatically actuated cantilever and metal contact based series RF MEMS Switch is designed and analyzed using Finite Element Method Tool. The designed switch is simulated and the performance is verified over the frequency range 0.8–20 GHz. In investigation, it is noticed that the performance of the RF MEMS Switch is decided by the actuation voltage, insertion losses, isolation losses and reliability. The switch designed in this paper achieved a constant insertion losses of −0.08 to −0.14 dB, isolation losses of −58 to −20 dB. This work also concentrated on the cantilever actuation voltage, and it is reduced to 3.55 V by using less weight polymer material like Poly Tetra Fluoro Ethylene (PTFE). The series metal contact based electrostatically driven switching is created in Microstrip Transmission line using cantilever structure associated with gold contact material. The designed RF MEMS switch is preferable in the design and implementation of reconfigurable communi...

Robotic mechanical design for brick-laying automation

Abstract: This paper investigates the potential for automation of masonry work. A brick-laying robot was designed and the robot’s design criteria were such that it should be able to construct a wall using ci...

Selection criteria of dc-dc converter and control variable for MPPT of PV system utilized in heating and cooking applications

Abstract: This paper deals with the selection of dc-dc converter and control variable required to track the maximum power of photovoltaic (PV) array, to optimize the utilization of solar power. To reduce the maintenance cost and to simplify the model, the battery has not been used in the proposed PV system mainly used for cooking and heating applications. Since the battery has not been used, selection of dc-dc converter is an important consideration of the PV system in standalone applications. In the proposed system converter is selected based on maximum power transfer theorem which is dependent on load resistance. Different load resistance is considered for maximum power point tracking (MPPT) with different converter topologies, and it has been observed that buck-boost converter is suitable for any load resistance connected in the PV system. An effort has been taken to suitably choosing the control variable which is the output signal of the maximum power point (MPP) tracker. Control variable which is depen...

Re-use of steel slag as an aggregate to asphaltic road pavement surface

Abstract: Electric arc Furnace steel slag produced from the ferrous smelting process in the manufacture of steel in Trinidad and Tobago presents disposal and environmental challenges. Research has demonstrat...

Public water supply in Lagos State, Nigeria: Review of importance and challenges, status and concerns and pragmatic solutions

Abstract: The challenges faced in public water supply in most cities and developing countries are increasing population size, poor operational efficiency of existing waterworks, leakages, low reticulation co...

VANET routing protocol for V2V implementation: A suitable solution for developing countries

Abstract: During the last decade Intelligent Transportation System (ITS) research and development, including its implementation in a real life going through the optimization in order to have the best and acc...

Studies on the properties of pervious fly ash–cement concrete as a pavement material

Abstract: The aim of this study is to investigate the effect of variation of cement content, partial replacement of cement by 10 and 20% of fly ash, partial replacement of coarse aggregate by fine aggregates (ranging from 5 to 15%) with the addition of plasticizer on the characteristics of pervious concrete. Class C fly ash was used for the production of pervious concrete, adopting ACI method of mix proportioning. Coarse aggregates of size 19 to 9.5 mm and 9.5 to 4.75 mm blended in the ratio of 60:40 respectively, a constant water—binder ratio of 0.3, a plasticizer of 0.8% by weight of cement were adopted. Density, compressive strength, flexural strength, split tensile strength, total voids, permeable voids, permeability by falling head method, sand blasting abrasion and cantabro abrasion were determined. Replacement of cement by fly ash (up to 20%) has reduced the compressive strength marginally, whereas, addition of fine aggregates (5–15%) has increased the above strength ranging from “marginal” to “high”...

Limiting factors for the use of palm oil biodiesel in a diesel engine in the context of the ASTM standard

Abstract: Biodiesel is a biodegradable fuel contains fatty acid methyl or ethyl esters which are typically produced by the transesterification reaction among the triglycerides in the vegetable oils or animal...

Influence of granulated blast furnace slag on mechanical properties of foam concrete

Abstract: This paper experimentally comparing the mechanical properties between ground granulated blast furnace slag (GGBS) and unground blast furnace slag (GBS) as a partial replacement for cement for the p...

Significant contributors to cost overruns in construction projects of Cambodia

Abstract: Construction industry is one of the leading sectors with its remarkable contribution to the GDP and employment generation in Cambodia. However, one of the major challenges facing the construction i...

Synthetic sustainability index (SSI) based on life cycle assessment approach of low impact development in the Mediterranean area

Abstract: Climate change and the processes of urbanization alter the hydrologic and hydraulic regime of runoffs formation in urban areas. Low impact infrastructure development (LID) contributes to achieving ...

Optimizing the rheological properties of silica nano-modified bentonite mud using overlaid contour plot and estimation of maximum or upper shear stress limit

Abstract: An optimization based statistical (response surface) approach was used to evaluate the rheological properties of bentonite mud treated with silica nanoparticles. The overlaid contour plot established the feasible region for the various factor settings from multiple regression equations. The steepest method was used to further determine the optimal factor settings for minimum rheological properties and this was established at 6.3 wt.% bentonite content and 0.94 wt.% silica nanoparticles. The rheological properties of the bentonite mud containing and without silica nanoparticles was evaluated using a Hyperbolic (new) model and related with other oil industry based models: Herschel Bulkley, Sisko, Casson. The hyperbolic rheological model estimated the rheological behaviour of the nano-modified mud satisfactorily while also predicting a shear stress limit for the nano-modified mud. The maximum shear stress limit values for 6.3, 13 and 15 wt.% mud were 14.59, 61.74 and 107.4 Pa respectively. Upper shea...

Experimental investigation and optimization of cutting parameters with multi response characteristics in MQL turning of AISI 4340 using nano fluid

Abstract: To increase the productivity in machining industries demand for better surface finish and accuracy has been increasing rapidly in recent years. Therefore, this paper focus on an effective approach for the optimization of process parameters in Minimum Quantity Lubrication (MQL) turning of AISI 4340 with nano fluid by using Grey Relational Analysis (GRA). Sixty experimental trials based on full factorial design matrix were carried on CNC turning lathe machine to optimize best level. Analysis of experimental results for response variable such as surface roughness and cutting force was performed using Grey Relational Grade (GRG). From GRA the optimal conditions are obtained as cutting speed (75 m/min), Feed (0.04 mm/rev), Depth of cut (0.5 mm) and Tool nose radius (0.8 mm) for optimal response variable surface roughness (1.26 μm) and cutting force (7.69 kgf). The Signal to Noise ratio plot for GRA shows similar optimum condition therefore the results obtained from ANOVA are closely matching to the res...

Hydration mechanism and strength properties of recycled aggregate concrete made using ceramic blended cement

Abstract: A pozzolanic material ordinarily contains high amounts of siliceous or aluminous components, but has no cementitious property until when it reacts with calcium hydroxide, that is available in cement, in the presence of moisture. The present study evaluates the pozzolanicity of ceramic tile powder and its effect on both hydration mechanism and strength property of recycled aggregate concrete. It was seen that ceramic floor and wall tiles sourced from construction and demolition wastes, contain high silica and alumina oxides, which evidently showcased its pozzolanicity. This was further revealed by the microstructural images of ceramic blended cement. Strength properties of recycled aggregate concrete were enhanced with addition of ceramic powder and ceramic coarse fraction, more than the strength developed in the control concrete. The increased strength was an indication that the interfacial transition zone between the aggregate and blended cement paste enhanced the properties of recycled aggregate...

Impact of hybrid system in polyester production

Abstract: This study represents the evaluation of energy efficiency improvement using combination of natural gas, solar energy and flue gases heat recovery in polyester production. The analyzed energy sources are used for dry saturated steam generation. The energy consumption for combined system on location (φ = 45°49′) with collector field of 23.23 × 103 m2, was investigated. The hybrid system was calculated for four variants: (1) solarized process without flue gases heat recovery, (2) solarized processes with heat contend in flue gases using economizer, (3) solarized processes with heat contend in flue gases using an air preheater and (4) solarized processes with heat contend in flue gases using economizer and air preheater. The best method among presented sources is solution using economizer and the air preheater with natural gas, solar energy and flue gases heat recovery. The natural gas consumption is reduced for 67.82% which indicates that this solution is the optimal one. At the same time the volume ...

Use of paper mill waste for brick making

Abstract: The intent of the present research work is to explore the prospect of replacing natural soil used in brick making by some extent with industrial waste, that is, lime mud, as obtained from paper mil...

Optimal bidding strategy for price takers and customers in a competitive electricity market

Abstract: Bidding strategies are highly associated with the profit maximization and decreasing the risks for power utilities in a competitive market. For finding the optimal bidding strategies price takers need appropriate bidding structure. Thus, it is required to consider the model as a bi-level optimization problem. In the lower level price takers submit bid strategically to the ISO and in the upper level maximization of social welfare performed by solving the ISO Market clearing price (MCP). This paper aim to summarize the price taker’s bidding strategy modeling methods for competitive market models on the state-of-the art. A new genetic algorithm approach in a day-ahead electricity market in sealed auction with a pay-as-bid MCP has been employed to solve the problem from two different viewpoints i.e. with symmetrical and unsymmetrical information. The efficiency of the proposed method has been tested on the IEEE-30 bus system.