Abstract: In this research, copper borates are synthesized by the
reaction of copper sulfate pentahydrate (CuSO4.5H2O) and
tincalconite (Na2O4B7.10H2O). The experimental parameters are
selected as 80oC reaction temperature and 60 of reaction time. The
effect of mole ratio of CuSO4.5H2O to Na2O4B7.5H2O is studied. For
the identification analyses X-Ray Diffraction (XRD) and Fourier
Transform Infrared Spectroscopy (FT-IR) techniques are used. At the
end of the experiments, synthesized copper borate is matched with
the powder diffraction file of “00-001-0472” [Cu(BO2)2] and
characteristic vibrations between B and O atoms are seen. The proper
crystals are obtained at the mole ratio of 3:1. This study showed that
simplified synthesis process is suitable for the production of copper
borate minerals.
Abstract: Reconfigurable antennas represent a recent innovation in antenna design that changes from classical fixed-form, fixed function antennas to modifiable structures that can be adapted to fit the requirements of a time varying system.
The ability to control the operating band of an antenna system can have many useful applications. Systems that operate in an acquire-and-track configuration would see a benefit from active bandwidth control. In such systems a wide band search mode is first employed to find a desired signal then a narrow band track mode is used to follow only that signal. Utilizing active antenna bandwidth control, a single antenna would function for both the wide band and narrow band configurations providing the rejection of unwanted signals with the antenna hardware. This ability to move a portion of the RF filtering out of the receiver and onto the antenna itself will also aid in reducing the complexity of the often expensive RF processing subsystems.
Abstract: An experimental study was conducted to investigate the effect of hooked-end steel fibers on the flexural behavior of normal and high strength concrete matrices. The fibers content appropriate for the concrete matrices investigated was also determined based on flexural tests on standard prisms. Parameters investigated include: matrix compressive strength ranging from 45 MPa to 70 MPa, corresponding to normal and high strength concrete matrices respectively; fibers volume fraction including 0, 0.5%, 0.76% and 1%, equivalent to 0, 40, 60, and 80 kg/m3 of hooked-end steel fibers respectively. Test results indicated that flexural strength and toughness of normal and high strength concrete matrices were significantly improved with the increase in the fibers content added; whereas a slight improvement in compressive strength was observed for the same matrices. Furthermore, the test results indicated that the effect of increasing the fibers content was more pronounced on increasing the flexural strength of high strength concrete than that of normal concrete.
Abstract: Cubic equations of state like Redlich–Kwong (RK)
EOS have been proved to be very reliable tools in the prediction of
phase behavior. Despite their good performance in compositional
calculations, they usually suffer from weaknesses in the predictions
of saturated liquid density. In this research, RK equation was
modified. The result of this study show that modified equation has
good agreement with experimental data.
Abstract: In this study, two kinds of nondestructive evaluation
(NDE) techniques (rebound hardness and ultrasonic pulse velocity
methods) are investigated for the effective maintenance of underwater
concrete structures. A new methodology to estimate the underwater
concrete strengths more effectively, named “artificial neural network
(ANN) – based concrete strength estimation with the combination of
rebound hardness and ultrasonic pulse velocity methods” is proposed
and verified throughout a series of experimental works.
Abstract: Service quality is the highest requirement by users,
especially for the service in electronic government. During the past
decades, it has become a major area of academic investigation.
Considering this issue, there are a lot of researches that evaluated the
dimensions and e-service contexts. This study also identified the
dimensions of service quality, but focuses on a new concept and
provides a new methodology in developing measurement scales of
e-service quality such as information quality, service quality and
organization quality. Finally, this study will suggest a key factor to
evaluate e-government service quality better.
Abstract: The efficiency of heavy metals removal from sewage
sludge in bioleaching processes with heterotrophic, chemoautotrophic
(sulphur-oxidizing) sludge cenoses and chemical leaching (in
distilled water, weakly acidic or alkaline medium) was compared.
The efficacy of heavy metals removal from sewage sludge varies
from 83 % (Zn) up to 14 % (Cr) and follows the order: Zn > Mn > Cu
> Ni > Co > Pb > Cr. The advantages of metals bioleaching process
at heterotrophic metabolism were shown. A new process for
bioconversation of sewage sludge into fertilizer at middle
temperatures after partial heavy metals removal was developed. This
process is based on enhancing vital ability of heterotrophic
microorganisms by adding easily metabolized nutrients and synthesis
of metabolites by growing sludge cenoses. These metabolites possess
the properties of heavy metals extractants and flocculants which
provide the enhancement of sludge flocks sedimentation. The process
results in biomineral fertilizer of prolonged action with immobilized
sludge bioelements. The fertilizer satisfies the EU limits for the
sewage sludge of agricultural utilization. High efficiency of the
biomineral fertilizer obtained has been demonstrated in vegetation
experiments.
Abstract: In this research, the TRACE/PARCS model of
Lungmen ABWR has been developed for verification of ultimate
response guideline (URG) efficiency. This ultimate measure was
named as DIVing plan, abbreviated from system depressurization,
water injection and containment venting. The simulation initial
condition is 100% rated power/100% rated core flow. This research
focuses on the estimation of the time when the fuel might be damaged
with no water injection by using TRACE/PARCS first. Then, the
effect of the reactor core isolation system (RCIC), control
depressurization and ac-independent water addition system (ACIWA),
which can provide the injection with 950 gpm are also estimated for
the station blackout (SBO) transient.
Abstract: In this paper the intelligent control of full automatic car wash using a programmable logic controller (PLC) has been investigated and designed to do all steps of carwashing. The Intelligent control of full automatic carwash has the ability to identify and profile the geometrical dimensions of the vehicle chassis. Vehicle dimension identification is an important point in this control system to adjust the washing brushes position and time duration. The study also tries to design a control set for simulating and building the automatic carwash. The main purpose of the simulation is to develop criteria for designing and building this type of carwash in actual size to overcome challenges of automation. The results of this research indicate that the proposed method in process control not only increases productivity, speed, accuracy and safety but also reduce the time and cost of washing based on dynamic model of the vehicle. A laboratory prototype based on an advanced intelligent control has been built to study the validity of the design and simulation which it’s appropriate performance confirms the validity of this study.
Abstract: Grinding requires high specific energy and the consequent development of high temperature at tool-workpiece contact zone impairs workpiece quality by inducing thermal damage to the surface. Finishing grinding process requires component to be cut more than one pass. This paper deals with an investigation on the effect of multipass cutting on grinding performance in term of surface roughness and surface defect. An experimental set-up has been developed for this and a detailed comparison has been done with a single pass and various numbers of cutting pass. Results showed that surface roughness increase with the increase in a number of cutting pass. Good surface finish of 0.26μm was obtained for single pass cutting and 0.73μm for twenty pass cutting. It was also observed that the thickness of the white layer increased with the increased in a number of cutting pass.
Abstract: The development of new construction materials using
recycled plastic is important to both the construction and the plastic
recycling industries. Manufacturing of fibers from industrial or
postconsumer plastic waste is an attractive approach with such
benefits as concrete performance enhancement, and reduced needs
for land filling. The main objective of this study is to investigate the
effect of Plastic fibers obtained locally from recycled waste on plastic
shrinkage cracking of ordinary cement based mortar. Parameters
investigated include: fiber length ranging from 20 to 50mm, and fiber
volume fraction ranging from 0% to 1.5% by volume. The test results
showed significant improvement in crack arresting mechanism and
substantial reduction in the surface area of cracks for the mortar
reinforced with recycled plastic fibers compared to plain mortar.
Furthermore, test results indicated that there was a slight decrease in
compressive strength of mortar reinforced with different lengths and
contents of recycled fibers compared to plain mortar. This study
suggests that adding more than 1% of RP fibers to mortar, can be
used effectively for controlling plastic shrinkage cracking of cement
based mortar, and thus results in waste reduction and resources
conservation.
Abstract: Green mussels (Perna viridis) can effectively remove
nutrients from seawater through their filtration process. This study
aims to estimate “net” nutrient removal rate by green mussel through
calculation of nutrient uptake and release. Nutrients (carbon, nitrogen
and phosphorus) uptake was calculated based on the mussel filtration
rate. Nutrient release was evaluated from carbon, nitrogen and
phosphorus released as mussel faeces. By subtracting nutrient release
from nutrient uptake, net nutrient removal by green mussel can be
found as 3302, 380 and 124 mg/year/indv. Mass balance model was
employed to simulate nutrient removal in actual green mussel
farming conditions. Mussels farm area, seawater flow rate, and
amount of mussels were considered in the model. Results show that
although larger quantity of green mussel farms lead to higher nutrient
removal rate, the maximum green mussel cultivation should be taken
into consideration as nutrients released through mussel excretion can
strongly affect marine ecosystem.
Abstract: This study is conducted to investigate the disparity of between learning styles and cognitive abilities specifically in Vocational Education. Felder and Silverman Learning Styles Model (FSLSM) was applied to measure the students’ learning styles while the content in Building Construction Subject consists; knowledge, skills and problem solving were taken into account in constructing the elements of cognitive abilities. Building Construction is one of the vocational courses offered in Vocational Education structure. There are four dimension of learning styles proposed by Felder and Silverman intended to capture student learning preferences with regards to processing either active or reflective, perception based on sensing or intuitive, input of information used visual or verbal and understanding information represent with sequential or global learner. Felder-Solomon Learning Styles Index was developed based on FSLSM and the questions were used to identify what type of student learning preferences. The index consists 44 item-questions characterize for learning styles dimension in FSLSM. The achievement test was developed to determine the students’ cognitive abilities. The quantitative data was analyzed in descriptive and inferential statistic involving Multivariate Analysis of Variance (MANOVA). The study discovered students are tending to be visual learners and each type of learner having significant difference whereas cognitive abilities there are different finding for each type of learners in knowledge, skills and problem solving. This study concludes the gap between type of learner and the cognitive abilities in few illustrations and it explained how the connecting made. The finding may help teachers to facilitate students more effectively and to boost the student’s cognitive abilities.
Abstract: Although a lot of importance has been given to resistance analysis for various vessel types, explicit guidelines applied to multihull vessels have not been clearly defined. The purpose of this investigation is to highlight the importance of the vessel’s layout in terms of three axes, the transverse (separation), the longitudinal (stagger) and the vertical (draught) with respect to resistance analysis. When a vessel has the potential to experience less resistance at a particular range of speeds a vast selection of opportunities are made available for both the commercial and leisure market.
Abstract: This paper was prepared to see the perceptions of online lectures regarding collaborative learning, in terms of how lecturers view online collaborative learning in the higher learning institution. The purpose of this study was conducted to determine the perceptions of online lectures about collaborative learning, especially how lecturers see online collaborative learning in the university. Adult learning education enhance collaborative learning culture with the target of involving learners in the learning process to make teaching and learning more effective and open at the university. This will finally make students learning that will assist each other. It is also to cut down the pressure of loneliness and isolation might felt among adult learners. Their ways in collaborative online was also determined. In this paper, researchers collect data using questionnaires instruments. The collected data were analyzed and interpreted. By analyzing the data, researchers report the results according the proof taken from the respondents. Results from the study, it is not only dependent on the lecturer but also a student to shape a good collaborative learning practice. Rational concepts and pattern to achieve these targets be clear right from the beginning and may be good seen by a number of proposals submitted and include how the higher learning institution has trained with ongoing lectures online. Advantages of online collaborative learning show that lecturers should be trained effectively. Studies have seen that the lecturer aware of online collaborative learning. This positive attitude will encourage the higher learning institution to continue to give the knowledge and skills required.
Abstract: This article deals with the carbon nanotubes (CNT) synthesized from a novel precursor, sugar cane and Anodic Aluminum Oxide (AAO). The objective was to produce CNTs to be used as catalyst supports for Proton Exchange Membranes. The influence of temperature, inert gas flow rate and concentration of the precursor is presented. The CNTs prepared were characterized using TEM, XRD, Raman Spectroscopy, and the surface area determined by BET. The results show that it is possible to form CNT from sugar cane by pyrolysis and the CNTs are the type multi-walled carbon nanotubes. The MWCNTs are short and closed at the two ends with very small surface area of SBET= 3.691m,/g.
Abstract: This study aims to determine change in optimal locations of dual trailing-edge flaps for various thrust coefficient to solidity (Ct /σ) ratios of helicopter to achieve minimum hub vibration levels, with low penalty in terms of required trailing-edge flap control power. Polynomial response functions are used to approximate hub vibration and flap power objective functions. Single objective and multiobjective optimization is carried with the objective of minimizing hub vibration and flap power. The optimization result shows that the inboard flap location at low Ct /σ ratio move farther from the baseline value and at high Ct /σ ratio move towards the root of the blade for minimizing hub vibration.
Abstract: New developed approach for Functional Cost Analysis (FCA) based on virtual prototyping (VP) models in CAD/CAE environment, applicable and necessary in developing new products is presented. It is instrument for improving the value of the product while maintaining costs and/or reducing the costs of the product without reducing value. Five broad classes of VP methods are identified. Efficient use of prototypes in FCA is a vital activity that can make the difference between successful and unsuccessful entry of new products into the competitive word market. Successful realization of this approach is illustrated for a specific example using press joint power tool.
Abstract: The objective in this work is to generate and discuss the stability results of fully-immersed end-milling process with parameters; tool mass m=0.0431kg,tool natural frequency ωn = 5700 rads^-1, damping factor ξ=0.002 and workpiece cutting coefficient C=3.5x10^7 Nm^-7/4. Different no of teeth is considered for the end-milling. Both 1-DOF and 2-DOF chatter models of the system are generated on the basis of non-linear force law. Chatter stability analysis is carried out using a modified form (generalized for both 1-DOF and 2-DOF models) of recently developed method called Full-discretization. The full-immersion three tooth end-milling together with higher toothed end-milling processes has secondary Hopf bifurcation lobes (SHBL’s) that exhibit one turning (minimum) point each. Each of such SHBL is demarcated by its minimum point into two portions; (i) the Lower Spindle Speed Portion (LSSP) in which bifurcations occur in the right half portion of the unit circle centred at the origin of the complex plane and (ii) the Higher Spindle Speed Portion (HSSP) in which bifurcations occur in the left half portion of the unit circle. Comments are made regarding why bifurcation lobes should generally get bigger and more visible with increase in spindle speed and why flip bifurcation lobes (FBL’s) could be invisible in the low-speed stability chart but visible in the high-speed stability chart of the fully-immersed three-tooth miller.
Abstract: This paper presents the results of a study aimed at establishing the temperature distribution during the welding of aluminum alloy plates by Pulsed Current Gas Tungsten Arc Welding (PCGTAW) and Constant Current Gas Tungsten Arc Welding (CCGTAW) processes. Pulsing of the GTA welding current influences the dimensions and solidification rate of the fused zone, it also reduces the weld pool volume hence a narrower bead. In this investigation, the base material considered was aluminum alloy AA 6351 T6, which is finding use in aircraft, automobile and high-speed train components. A finite element analysis was carried out using ANSYS, and the results of the FEA were compared with the experimental results. It is evident from the study that the finite element analysis using ANSYS can be effectively used to model PCGTAW process for finding temperature distribution.