Abstract: This work presents the modelling and simulation of
saponification of ethyl acetate in the presence of sodium hydroxide in
a plug flow reactor using Aspen Plus simulation software. Plug flow
reactors are widely used in the industry due to the non-mixing
property. The use of plug flow reactors becomes significant when
there is a need for continuous large scale reaction or fast reaction.
Plug flow reactors have a high volumetric unit conversion as the
occurrence for side reactions is minimum. In this research Aspen Plus
V8.0 has been successfully used to simulate the plug flow reactor. In
order to simulate the process as accurately as possible HYSYS Peng-
Robinson EOS package was used as the property method. The results
obtained from the simulation were verified by the experiment carried
out in the EDIBON plug flow reactor module. The correlation
coefficient (r2) was 0.98 and it proved that simulation results
satisfactorily fit for the experimental model. The developed model
can be used as a guide for understanding the reaction kinetics of a
plug flow reactor.
Abstract: This paper proposes a cooperative Alamouti space time
transmission scheme with low relay complexity for the cooperative
communication systems. In the proposed scheme, the source node
combines the data symbols to construct the Alamouti-coded form at
the destination node, while the conventional scheme performs the
corresponding operations at the relay nodes. In simulation results,
it is shown that the proposed scheme achieves the second order
cooperative diversity while maintaining the same bit error rate (BER)
performance as that of the conventional scheme.
Abstract: In this paper, GSM signal strength was measured in
order to detect the type of the signal fading phenomenon using onedimensional
multilevel wavelet residual method and neural network
clustering to determine the average GSM signal strength received in
the study area. The wavelet residual method predicted that the GSM
signal experienced slow fading and attenuated with MSE of 3.875dB.
The neural network clustering revealed that mostly -75dB, -85dB and
-95dB were received. This means that the signal strength received in
the study is a weak signal.
Abstract: Electronic market place plays an important
intermediary role for connecting dealers and retail customers. The
main aim of this paper is to design a value co-creation model in
used-car auctions. More specifically, the study has been designed in
order to describe the process of value co-creation in used-car auctions,
to explore the co-created values in used-car auctions, and finally
conclude the paper indicating the future research directions. Our
analysis shows that economic values as well as non-economic values
are co-created in used-car auctions. In addition, this paper contributes
to the academic society broadening the view of value co-creation in
service science.
Abstract: This paper presents the application of finite dynamic
programming, specifically the "Markov Chain" model, as part of the
decision making process of a company in the cosmetics sector located
in the vicinity of Bogota DC. The objective of this process was to
decide whether the company should completely reconstruct its
wastewater treatment plant or instead optimize the plant through the
addition of equipment. The goal of both of these options was to make
the required improvements in order to comply with parameters
established by national legislation regarding the treatment of waste
before it is released into the environment. This technique will allow
the company to select the best option and implement a solution for
the processing of waste to minimize environmental damage and the
acquisition and implementation costs.
Abstract: The objectives of this research were to study the
influencing factors that contributed to the success of e-collaborative
in e-commerce of B2C (Business to Customer) business in Bangkok,
Thailand. The influencing factors included organization, people,
information technology and the process of e-collaborative. A
questionnaire was used to collect data from 200 small e-commerce
businesses and the path analysis was utilized as the tool for data
analysis.
By using the path analysis, it was revealed that the factors
concerning with organization, people and information technology
played an influence on e-collaborative process and the success of ecollaborative,
whereas the process of e-collaborative factor
manipulated its success. The findings suggested that B2C ecommerce
business in Thailand should opt in improvement approach
in terms of managerial structure, leaderships, staff’s skills and
knowledge, and investment of information technology in order to
capacitate higher efficiency of e-collaborative process that would
result in profit and competitive advantage.
Abstract: The study examines the influence of marital status on
consumers of products and services using blogs as a source of
information. A pre-designed questionnaire was used to collect the
primary data from the respondents (experiences). Data were collected
from one hundred and eighty seven respondents residing in and
around the Emirates of Sharjah and Dubai of the United Arab
Emirates. The collected data was analyzed with the help of statistical
tools such as averages, percentages, factor analysis, Student’s t-test
and Structural Equation Modelling Technique.
Objectives of the study are to know the reasons how married and
unmarried or single consumers of products and services are
motivated to use blogs as a source of information, to know whether
the consumers of products and services irrespective of their marital
status share their views and experiences with other bloggers and to
know the respondents’ future intentions towards blogging.
The study revealed the following: Majority of the respondents
have the motivation to blog because they are willing to receive
comments on what they post about services, convenience of blogs to
search for information about services and products, by blogging
respondents share information on the symptoms of a disease/ disorder
that may be experienced by someone, helps to share information
about ready to cook mix products and are keen to spend more time
blogging in the future.
Abstract: The biomass-based fuels have become great concern in order to replace the petroleum-based fuels. Biofuels are a wide range of fuels referred to liquid, gas and solid fuels produced from biomass. Recently, higher chain alcohols such as 3-methyl-1-butanol and isobutanol have become a better candidate compared to bioethanol in order to replace gasoline as transportation fuel. Therefore, in this study, 3-methyl-1-butanol was produced through a fermentation process by yeast. Several types of yeast involved in this research including Saccharomyces cerevisiae, Kluyveromyces lactis GG799 and Pichia pastoris (KM71H, GS115 and X33). The result obtained showed that K. lactis GG799 gave the highest concentration of 3-methyl-1-butanol at 274 mg/l followed by S. cerevisiae, P. pastoris GS115, P. pastoris KM71H and P. pastoris X33 at 265 mg/l, 190 mg/l, 182 mg/l and 174 mg/l respectively. Based on the result, it proved that yeast have a potential in producing 3-methyl-1-butanol naturally.
Abstract: There is an essential need for obtaining the mathematical representation of fish body undulations, which can be used for designing and building new innovative types of marine propulsion systems with less environmental impact. This research work presents a case study to derive the mathematical model for fish body movement. Observation and capturing image methods were used in this study in order to obtain a mathematical representation of Clariasbatrachus fish (catfish). An experiment was conducted by using an aquarium with dimension 0.609 m x 0.304 m x 0.304 m, and a 0.5 m ruler was attached at the base of the aquarium. Progressive Scan Monochrome Camera was positioned at 1.8 m above the base of the aquarium to provide swimming sequences. Seven points were marked on the fish body using white marker to indicate the fish movement and measuring the amplitude of undulation. Images from video recordings (20 frames/s) were analyzed frame by frame using local coordinate system, with time interval 0.05 s. The amplitudes of undulations were obtained for image analysis from each point that has been marked on fish body. A graph of amplitude of undulations versus time was plotted by using computer to derive a mathematical fit. The function for the graph is polynomial with nine orders.
Abstract: An extensive amount of work has been done in data
clustering research under the unsupervised learning technique in Data
Mining during the past two decades. Moreover, several approaches
and methods have been emerged focusing on clustering diverse data
types, features of cluster models and similarity rates of clusters.
However, none of the single clustering algorithm exemplifies its best
nature in extracting efficient clusters. Consequently, in order to
rectify this issue, a new challenging technique called Cluster
Ensemble method was bloomed. This new approach tends to be the
alternative method for the cluster analysis problem. The main
objective of the Cluster Ensemble is to aggregate the diverse
clustering solutions in such a way to attain accuracy and also to
improve the eminence the individual clustering algorithms. Due to
the massive and rapid development of new methods in the globe of
data mining, it is highly mandatory to scrutinize a vital analysis of
existing techniques and the future novelty. This paper shows the
comparative analysis of different cluster ensemble methods along
with their methodologies and salient features. Henceforth this
unambiguous analysis will be very useful for the society of clustering
experts and also helps in deciding the most appropriate one to resolve
the problem in hand.
Abstract: The purpose of this work is to optimize a Switched Reluctance Motor (SRM) for an automotive application, specifically for a fully electric car. A new optimization approach is proposed. This unique approach transforms automotive customer requirements into an optimization problem, based on sound knowledge of a SRM theory. The approach combines an analytical and a finite element analysis of the motor to quantify static nonlinear and dynamic performance parameters, as phase currents and motor torque maps, an output power and power losses in order to find the optimal motor as close to the reality as possible, within reasonable time. The new approach yields the optimal motor which is competitive with other types of already proposed motors for automotive applications. This distinctive approach can also be used to optimize other types of electrical motors, when parts specifically related to the SRM are adjusted accordingly.
Abstract: In this paper the vibration of a synchronous belt drive
during start-up is analyzed and discussed. Besides considering the
belt elasticity, the model here proposed also takes into consideration
the electromagnetic response of the DC motor. The solution of the
motion equations is obtained by means of the modal analysis in
state space, which allows to obtain the decoupling of all equations,
without introducing the hypothesis of proportional damping. The
mathematical model of the transmission and the solution algorithms
have been implemented within a computing software that allows the
user to simulate the dynamics of the system and to evaluate the effects
due to the elasticity of the belt branches and to the electromagnetic
behavior of the DC motor. In order to show the details of the
calculation procedure, the paper presents a case study developed with
the aid of the above-mentioned software.
Abstract: The concept of corporate social responsibility (CSR) in the Czech Republic has evolved notably during the last few years and an issue that started as an interest- and motive-based activity for businesses is becoming more commonplace. Governments have a role to play in ensuring that corporations behave according to the rules and norms of society and can legislate, foster, collaborate with businesses and endorse good practice in order to facilitate the development of CSR. The purpose of this paper is to examine the opportunities and options of CSR in government policy and research its relevance to a business sector. An increasing number of companies is engaging in responsible activities, the public awareness of CSR is rising, and customers are giving higher importance to CSR of companies in their choice. By drawing on existing CSR approach in Czech and understanding of CSR are demonstrated. The paper provides an overview, more detailed government approach of CSR.
Abstract: Amyloid aggregation of polypeptides is related to a
growing number of pathologic states known as amyloid disorders. In
recent years, blocking or reversing amyloid aggregation via the use of
small compounds are considered as two useful approaches in
hampering the development of these diseases. In this research, we
have compared the ability of several manganese-salen derivatives, as
synthetic compounds, and apigenin, as a natural flavonoid, to inhibit
of hen egg-white lysozyme (HEWL) aggregation, as an in vitro
model system.
Different spectroscopic analyses such as Thioflavin T (ThT) and
Anilinonaphthalene-8-sulfonic acid (ANS) fluorescence, Congo red
(CR) absorbance along with transmission electron microscopy were
used in this work to monitor the HEWL aggregation kinetic and
inhibition. Our results demonstrated that both type of compounds
were capable to prevent the formation of lysozyme amyloid
aggregation in vitro. In addition, our data indicated that synthetic
compounds had higher activity to inhibit of the β-sheet structures
relative to natural compound. Regarding the higher antioxidant
activities of the salen derivatives, it can be concluded that in addition
to aromatic rings of each of the compounds, the potent antioxidant
properties of salen derivatives contributes to lower lysozyme fibril
accumulation.
Abstract: The use of low quality concrete has been identified as one of the main causes of the incessant collapse of buildings in Nigeria. Emphasis has been on the use of poor quality aggregates, poor workmanship and the use of lean concrete mix with low cement quantity as the reasons for the low quality of concrete used for building construction in Nigeria. Surveys conducted revealed that in the construction of most privately owned buildings where concrete trial mixes and concrete compressive strength quality assurance tests are not conducted, concretes used for building constructions are produced using the 1:2:4 mix ratio irrespective of the cement grade/strength class. In this paper, the possible role of the use of inappropriate cement grade/strength class as a cause of the incessant collapse of building in Nigeria is investigated. Investigation revealed that the compressive strengths of concrete cubes produced with Portland-limestone cement grade 32.5 using 1:2:4 and 1:1.5:3 mix ratios are less than the 25MPa and 30MPa cube strengths generally recommended for building superstructures and foundations respectively. Conversely, the compressive strengths of concrete cubes produced with Portland-limestone cement grade 42.5 using 1:2:4 and 1:1.5:3 mix ratios exceed the 25MPa and 30MPa generally recommended for building superstructures and foundations respectively. Thus, it can be concluded that the use of inappropriate cement grade (Portland-limestone cement grade 32.5), particularly for the construction of building foundations is a potential cause of the incessant collapse of buildings in Nigeria. It is recommended that the Standards Organisation of Nigeria should embark on creating awareness for Nigerians, particularly, the home owners and the roadside craftsmen that Portland-limestone cement grade 32.5 should not be used for the construction of building load-carrying members, particularly, building foundations in order to reduce the incessant incidence of collapsed building.
Abstract: This paper presents the findings of an experimental investigation of important machining parameters for the horizontal boring tool modified to mouth with a horizontal lathe machine to bore an overlength workpiece. In order to verify a usability of a modified tool, design of experiment based on Taguchi method is performed. The parameters investigated are spindle speed, feed rate, depth of cut and length of workpiece. Taguchi L9 orthogonal array is selected for four factors three level parameters in order to minimize surface roughness (Ra and Rz) of S45C steel tubes. Signal to noise ratio analysis and analysis of variance (ANOVA) is performed to study an effect of said parameters and to optimize the machine setting for best surface finish. The controlled factors with most effect are depth of cut, spindle speed, length of workpiece, and feed rate in order. The confirmation test is performed to test the optimal setting obtained from Taguchi method and the result is satisfactory.
Abstract: A vacuum fractionation technique was introduced to remove ethanol from fermentation broth. The effect of initial glucose and ethanol concentrations were investigated for specific productivity. The inhibitory ethanol concentration was observed at 100 g/L. In order to increase the fermentation performance, the ethanol product was removed as soon as it is produced. The broth was boiled at 35oC by reducing the pressure to 65 mBar. The ethanol/water vapor was fractionated for up to 90 wt% before leaving the column. Ethanol concentration in the broth was kept lower than 25 g/L, thus minimized the product inhibition effect to the yeast cells. For batch extractive fermentation, a high substrate utilization rate was obtained at 26.6 g/L.h and most of glucose was consumed within 21 h. For repeated-batch extractive fermentation, addition of glucose was carried out up to 9 times and ethanol was produced more than 8-fold higher than batch fermentation.
Abstract: It is necessary to manage the fatigue crack growth (FCG) once those cracks are detected during in-service inspections. In this paper, a simulation program (FCG-System) is developed utilizing the commercial software ABAQUS with its object-oriented programming interface to simulate the fatigue crack path and to compute the corresponding fatigue life. In order to apply FCG-System in large-scale marine structures, the substructure modeling technique is integrated in the system under the consideration of structural details and load shedding during crack growth. Based on the nodal forces and nodal displacements obtained from finite element analysis, a formula for shell elements to compute stress intensity factors is proposed in the view of virtual crack closure technique. The cracks initiating from the intersection of flange and the end of the web-stiffener are investigated for fatigue crack paths and growth lives under water pressure loading and axial force loading, separately. It is found that the FCG-System developed by authors could be an efficient tool to perform fatigue crack growth analysis on marine structures.
Abstract: In this paper, the design problem of state estimator for
neural networks with the mixed time-varying delays are investigated
by constructing appropriate Lyapunov-Krasovskii functionals and
using some effective mathematical techniques. In order to derive
several conditions to guarantee the estimation error systems to be
globally exponential stable, we transform the considered systems
into the neural-type time-delay systems. Then with a set of linear
inequalities(LMIs), we can obtain the stable criteria. Finally, three
numerical examples are given to show the effectiveness and less
conservatism of the proposed criterion.
Abstract: This research aimed to produce offset printing inks from Samut Songkram’s coconut oil and to test properties of the printing inks comparing with commercial offset printing inks. One of the ingredients in the process of mixing varnish is coconut oil – used to produce black offset printing inks which were the subject of testing issues in order to compare with commercial offset printing inks. Based on the results of research, the best formula for mixing varnish was 50% of coconut oil, 36% of phenolic resin, and 14% of solvent oil. At the same time, the best formula in producing black offset inks was mixing varnish with 20% of coconut oil 20%. Consequently, the result of testing of properties of coconut oil based solvent offset printing inks regarding viscosity, tack and ink flow, showed that offset printing inks with oil based solvent had the properties less than commercial offset printing ink. Additionally, the result of testing also indicate that the rate of properties in aspects of ink spread and setting time of coconut oil based solvent offset printing were higher than that of commercial offset printing inks.