Abstract: The fight against climate change and the replacement
of fossil energies nearing exhaustion gradually emerge as major
societal and economic challenges. It is possible to develop common
dates of low commercial value, and put on the local and international
market a new generation of products with high added values such as
bio ethanol. Besides its use in chemical synthesis, bio ethanol can be
blended with gasoline to produce a clean fuel while improving the
octane.
Abstract: Bureaucracy reform program drives Indonesian
government to change their management to enhance their
organizational performance. Information technology became one of
strategic plan that organization tried to improve. Knowledge
management system is one of information system that supporting
knowledge management implementation in government which
categorized as people perspective, because this system has high
dependency in human interaction and participation. Strategic plan for
developing knowledge management system can be determine using
some of information system strategic methods. This research
conducted to define type of strategic method of information system,
stage of activity each method, strength and weakness. Literature
review methods used to identify and classify strategic methods of
information system, differentiate method type, categorize common
activities, strength and weakness. Result of this research are
determine and compare six strategic information system methods,
Balanced Scorecard and Risk Analysis believe as common strategic
method that usually used and have the highest excellence strength.
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: Because of high thermal efficiency and low CO2
emission, diesel engines are being used widely in many industrial
fields although it makes many PM and NOx which give both human
health and environment a negative effect. NOx regulations for diesel
engines, however, are being strengthened and it is impossible to meet
the emission standard without NOx reduction devices such as SCR
(Selective Catalytic Reduction), LNC (Lean NOx Catalyst), and LNT
(Lean NOx Trap). Among the NOx reduction devices, urea-SCR
system is known as the most stable and efficient method to solve the
problem of NOx emission. But this device has some issues associated
with the ammonia slip phenomenon which is occurred by shortage of
evaporation and thermolysis time, and that makes it difficult to achieve
uniform distribution of the injected urea in front of monolith.
Therefore, this study has focused on the mixing enhancement between
urea and exhaust gases to enhance the efficiency of the SCR catalyst
equipped in catalytic muffler by changing inlet gas temperature and
spray conditions to improve the spray uniformity of the urea water
solution. Finally, it can be found that various parameters such as inlet
gas temperature and injector and injection angles significantly affect
the evaporation and mixing of the urea water solution with exhaust
gases, and therefore, optimization of these parameters are required.
Abstract: This paper presents the design and analysis of Liquid
Crystal (LC) based tunable reflectarray antenna with different design
configurations within X-band frequency range. The effect of LC
volume used for unit cell element on frequency tunability and
reflection loss performance has been investigated. Moreover different
slot embedded patch element configurations have been proposed for
LC based tunable reflectarray antenna design with enhanced
performance. The detailed fabrication and measurement procedure
for different LC based unit cells has been presented. The waveguide
scattering parameter measured results demonstrated that by using the
circular slot embedded patch elements, the frequency tunability and
dynamic phase range can be increased from 180MHz to 200MHz and
120° to 124° respectively. Furthermore the circular slot embedded
patch element can be designed at 10GHz resonant frequency with a
patch volume of 2.71mm3 as compared to 3.47mm3 required for
rectangular patch without slot.
Abstract: Abundant and cheap agricultural waste of oil palm trunk (OPT) juice was used to produce bioethanol. Two strains of Saccharomyces cerevisiae and a strain of Pichia stipitis were used to produce bioethanol from the OPT juice. Fermentation was conducted at previously optimized condition at 30oC and without shaking. The kinetic parameters were estimated and calculated. Monod equation and Hinshelwood model is used to relate the specific growth to the concentration of the limiting substrate and also to simulate bioethanol production rate. Among the three strains, single S. cerevisiae Kyokai no. 7 produce the highest ethanol yield of 0.477 g/l.h within the shortest time (12 h). This yeast also produces more than 20 g/l ethanol concentration within 10 h of fermentation.
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: The powders of Ba(Ce1-xZrx)0.90Y0.1O3-δ (BCZY) with 0.2 ≤ x ≤ 0.6 have been prepared by a modified sol-gel method. Triethylenetetramine (TETA) was employed as chelating agent. Phase formation of calcined powders at 1100oC and sintered pellets at 1400oC of BCZY were examined by an X-ray diffractrometer (XRD). XRD results showed the calcined powder and sintered pellet formed a single perovskite phase over the entire range of x values. As the amount of zirconium substitution (x values) increase, the main peaks are shifted to the higher 2theta values which suggest a complete substitution of zirconium into cerium sites. All the obtained calcined powders and sintered pellets possess cubic structure (Pm-3m) at all x values.
Abstract: Fluid rheology may have essential impact on sound propagation in a liquid-filled pipe, especially, in a low frequency range. Rheological parameters of liquid are temperature-sensitive, which ultimately results in a temperature dependence of the wave speed and attenuation in the waveguide. The study is devoted to modeling of this effect at sound propagation in an elastic pipe with polymeric liquid, described by generalized Maxwell model with non-zero high-frequency viscosity. It is assumed that relaxation spectrum is distributed according to the Spriggs law; temperature impact on the liquid rheology is described on the basis of the temperature-superposition principle and activation theory. The dispersion equation for the waveguide, considered as a thin-walled tube with polymeric solution, is obtained within a quasi-one-dimensional formulation. Results of the study illustrate the influence of temperature on sound propagation in the system.
Abstract: This paper presents the electrical effect of two neighboring distribution substation during the construction phase. The size of auxiliary grounding grid have an effect on entire grounding system. The bigger the size of auxiliary grounding grid, the lower the GPR and maximum touch voltage, with the exception that when the two grids are unconnected, i.e. the bigger the size of auxiliary grounding grid, the higher the maximum step voltage. The results in this paper could be served as design guideline of grounding system, and perhaps remedy of some troublesome grounding grids in power distribution’s system. Modeling and simulation is carried out on the Current Distribution Electromagnetic interference Grounding and Soil structure (CDEGS) program. The simulation results exhibit the design and analysis of power system grounding and perhaps could be set as a standard in grounding system design and modification in distribution substations.
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: A theoretical study has been presented to describe the boundary layer flow and heat transfer on an exponentially shrinking sheet with a variable wall temperature and suction, in the presence of magnetic field. The governing nonlinear partial differential equations are converted into ordinary differential equations by similarity transformation, which are then solved numerically using the shooting method. Results for the skin friction coefficient, local Nusselt number, velocity profiles as well as temperature profiles are presented through graphs and tables for several sets of values of the parameters. The effects of the governing parameters on the flow and heat transfer characteristics are thoroughly examined.
Abstract: In this paper, we present a new maintenance model
for a partially observable system subject to two failure modes,
namely a catastrophic failure and a failure due to the system
degradation. The system is subject to condition monitoring and the
degradation process is described by a hidden Markov model. A
cost-optimal Bayesian control policy is developed for maintaining
the system. The control problem is formulated in the semi-Markov
decision process framework. An effective computational algorithm is
developed, illustrated by a numerical example.
Abstract: In this paper influence of packaging method (vacuum
and modified atmosphere packaging) on lipid oxidative stability and
sensory properties of odor and taste of the traditional sausage
Petrovská klobása were examined. These parameters were examined
during storage period (7 months). In the end of storage period,
vacuum packed sausage showed better oxidative stability. Propanal
content was significantly lower (P
Abstract: The Analytic Hierarchy Process is frequently used
approach for solving decision making problems. There exists wide
range of software programs utilizing that approach. Their main
disadvantage is that they are relatively expensive and missing
intermediate calculations. This work introduces a Microsoft Excel
add-in called DAME – Decision Analysis Module for Excel.
Comparing to other computer programs DAME is free, can work
with scenarios or multiple decision makers and displays intermediate
calculations. Users can structure their decision models into three
levels – scenarios/users, criteria and variants. Items on all levels can
be evaluated either by weights or pair-wise comparisons. There are
provided three different methods for the evaluation of the weights of
criteria, the variants as well as the scenarios – Saaty’s Method,
Geometric Mean Method and Fuller’s Triangle Method.
Multiplicative and additive syntheses are supported. The proposed
software package is demonstrated on couple of illustrating examples
of real life decision problems.
Abstract: Strontium hexaferrite (SrFe12O19; Sr-ferrite) is one of
the well-known materials for permanent magnets. In this study, Mtype
strontium ferrite was prepared by following the conventional
ceramic method from steelmaking by-product. Initial materials;
SrCO3 and by-product, were mixed together in the composition of
SrFe12O19 in different Sr/Fe ratios. The mixtures of these raw
materials were dry-milled for 6h. The blended powder was presintered
(i.e. calcination) at 1000°C for different times periods, then
cooled down to room temperature. These pre-sintered samples were
re-milled in a dry atmosphere for 1h and then fired at different
temperatures in atmospheric conditions, and cooled down to room
temperature. The produced magnetic powder has a dense hexagonal
grain shape structure. The calculated energy product values for the
produced samples ranged from 0.3 to 2.4 MGOe.
Abstract: The mixed convection stagnation point flow toward a vertical plate is investigated. The external flow impinges normal to the heated plate and the surface temperature is assumed to vary linearly with the distance from the stagnation point. The governing partial differential equations are transformed into a set of ordinary differential equations, which are then solved numerically using MATLAB routine boundary value problem solver bvp4c. Numerical results show that dual solutions are possible for a certain range of the mixed convection parameter. A stability analysis is performed to determine which solution is linearly stable and physically realizable.
Abstract: In the present study we evaluated the nutritional status of 214 institutionalized elderly residents of both genders, aged 65 years and older of 11 care homes located in the district of Viseu (center of Portugal). The evaluation was based on anthropometric measurements and the Mini Nutritional Assessment (MNA) score.
The mean age of the subjects was 82.3 ± 6.1 years-old. Most of the elderly residents were female (72.0%). The majority had 4 years of formal education (51.9%) and was widowed (74.3%) or married (14.0%).
Men presented a mean age of 81.2±8.5 years-old, weight 69.3±14.5 kg and BMI 25.33±6.5 kg/m2. In women, the mean age was 84.5±8.2 years-old, weight 61.2±14.7 kg and BMI 27.43±5.6 kg/m2.
The evaluation of the nutritional status using the MNA score showed that 24.0% of the residents show a risk of undernutrition and 76.0% of them were well nourished.
There was a high prevalence of obese (24.8%) and overweight residents (33.2%) according to the BMI. 7.5% were considered underweight.
We also found that according to their waist circumference measurements 88.3% of the residents were at risk for cardiovascular disease (CVD) and 64.0% of them presented very high risk for CVD (WC≥88 cm for women and WC ≥102 cm for men).
The present study revealed the coexistence of a dual form of malnutrition (undernourished and overweight) among the institutionalized Portuguese concomitantly with an excess of abdominal adiposity. The high prevalence of residents at high risk for CVD should not be overlooked.
Given the vulnerability of the group of institutionalized elderly, our study highlights the importance of the classification of nutritional status based on both instruments: the BMI and the MNA.
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: Analytical expressions of the current and angular errors, as well as the frequency characteristics of an induction converter describing the relation with its structural parameters, the core and winding characteristics are obtained. Based on estimation of the dependences obtained, a mathematical problem of parametric optimization is formulated which can successfully be used for investigating and diagnosing an induction converter.