Abstract: This paper studies the design of a simple constellation
precoding for a multiple-input multiple-output orthogonal frequency
division multiplexing (MIMO-OFDM) system over Rayleigh fading
channels where OFDM is used to keep the diversity replicas orthogonal
and reduce ISI effects. A multi-user environment with K synchronous
co-channel users is considered. The proposed scheme provides
a bandwidth efficient transmission for individual users by increasing
the system throughput. In comparison with the existing coded
MIMO-OFDM schemes, the precoding technique is designed under
the consideration of its low implementation complexity while providing
a comparable error performance to the existing schemes.
Analytic and simulation results have been presented to show the distinguished
error performance.
Abstract: This interdisciplinary study is an investigation to evaluate user-interfaces in business administration. The study is going to be implemented on two computerized business administration systems with two distinctive user-interfaces, so that differences between the two systems can be determined. Both systems, a commercial and a prototype developed for the purpose of this study, deal with ordering of supplies, tendering procedures, issuing purchase orders, controlling the movement of the stocks against their actual balances on the shelves and editing them on their tabulations. In the second suggested system, modern computer graphics and multimedia issues were taken into consideration to cover the drawbacks of the first system. To highlight differences between the two investigated systems regarding some chosen standard quality criteria, the study employs various statistical techniques and methods to evaluate the users- interaction with both systems. The study variables are divided into two divisions: independent representing the interfaces of the two systems, and dependent embracing efficiency, effectiveness, satisfaction, error rate etc.
Abstract: In this work Membrane Distillation is applied to
concentrate orange Juice. Clarified orange juice (11o Brix) obtained
from fresh fruits and a sugar solution was subjected to membrane
distillation. The experiments were performed on a flat sheet module
using orange juice and sucrose solution as feeds. The concentration
of a sucrose solution, used as a model fruit juice and also orange
juice, was carried out in a direct contact membrane distillation using
hydrophobic PTFE membrane of pore size 0.2 μm and porosity 70%.
Surface modification of PTFE membrane has been carried out by
treating membrane with alcohol and water solution to make it
hydrophilic and then hydrophobicity was regained by drying. The
influences of the feed temperature, feed concentration, flow rate,
operating time on the permeate flux were studied for treated and non
treated membrane. In this work treated and non treated membrane
were compared in terms of water flux, Within the tested range, MD
with surface modified membrane the water flux has been
significantly improved by treating the membrane surface.
Abstract: The dilute acid pretreatment and enzymatic
saccharification of lignocellulosic substrate, cogon grass (Imperata
cylindrical, L.) was optimized prior ethanol fermentation using
simultaneous saccharification and fermentation (SSF) method. The
optimum pretreatment conditions, temperature, sulfuric acid
concentration, and reaction time were evaluated by determining the
maximum sugar yield at constant enzyme loading. Cogon grass, at
10% w/v substrate loading, has optimum pretreatment conditions of
126°C, 0.6% v/v H2SO4, and 20min reaction time. These
pretreatment conditions were used to optimize enzymatic
saccharification using different enzyme combinations. The maximum
saccharification yield of 36.68mg/mL (71.29% reducing sugar) was
obtained using 25FPU/g-cellulose cellulase complex combined with
1.1% w/w of cellobiase, ß-glucosidase, and 0.225% w/w of
hemicellulase complex, after 96 hours of saccharification. Using the
optimum pretreatment and saccharification conditions, SSF of treated
substrates was done at 37°C for 120 hours using industrial yeast
strain HBY3, Saccharomyces cerevisiae. The ethanol yield for cogon
grass at 4% w/w loading was 9.11g/L with 5.74mg/mL total residual
sugar.
Abstract: This paper studies, maps and explains the interactions between downloaders and uploaders pertaining to the Internet film piracy. This study also covers several motivational factors that influence users to upload or download movies, and thus to engage in film piracy over the Internet. The essay also proposes a model that describes user behavior including their relationships and influences. Moreover, proposed theoretical interactions and motivational factors are applied to the real world scenario, using examples of a data storage webpage server Ulozto.net and webpage Piratebay.org gathering information about downloadable BitTorrents. Moreover, the theory is further supported by description of behavior of real Internet uploaders.
Abstract: The heterotrophic seedling growth can be defined as a
product of two components: (1) the weight of mobilized seed reserve,
and (2) conversion efficiency of utilized seed reserve to seedling
tissue. The first component can be further divided into (1) initial seed
weight, and (2) the fraction of seed reserve, which is mobilized. The
objective of this study was the identification of the sensitive seedling
growth component(s) in response to drought and salinity stresses.
Two experiments were separately conducted using various salinity
levels (osmotic pressure) of 0, 0.25, 0.50, 0.75, 1, 1.25 and 1.5 MPa
created using NaCl as first experiment and by polyethylene glycol
(drought stress) of 0, 0.2, 0.4, 0.6, 0.8, 1, 1.2 and 1.4 MPa in second
experiment. Seeds of five crops species (Hordeum vulgare, Brassica
napus, Zea mays, Medicago sativa and Medicago scutellata) were
used in each experiment. In both experiments, seedling growth,
fraction of seed reserve utilization and weight of mobilized seed
reserve decreased with increasing drought and salt intensity.
However, drought and salinity stresses had no effect on the
conversion efficiency. It was concluded that the sensitive component
of seedling growth is the weight of mobilized seed reserve.
Abstract: Hierarchical Mobile IPv6 (HMIPv6) was designed to
support IP micro-mobility management in the Next Generation
Networks (NGN) framework. The main design behind this protocol is
the usage of Mobility Anchor Point (MAP) located at any level router
of network to support hierarchical mobility management. However,
the distance MAP selection in HMIPv6 causes MAP overloaded and
increase frequent binding update as the network grows. Therefore, to
address the issue in designing MAP selection scheme, we propose a
dynamic load control mechanism integrates with a speed detection
mechanism (DMS-DLC). From the experimental results we obtain
that the proposed scheme gives better distribution in MAP load and
increase handover speed.
Abstract: A nonlinear optimal controller with a fuzzy gain
scheduler has been designed and applied to a Line-Of-Sight (LOS)
stabilization system. Use of Linear Quadratic Regulator (LQR)
theory is an optimal and simple manner of solving many control
engineering problems. However, this method cannot be utilized
directly for multigimbal LOS systems since they are nonlinear in
nature. To adapt LQ controllers to nonlinear systems at least a
linearization of the model plant is required. When the linearized
model is only valid within the vicinity of an operating point a gain
scheduler is required. Therefore, a Takagi-Sugeno Fuzzy Inference
System gain scheduler has been implemented, which keeps the
asymptotic stability performance provided by the optimal feedback
gain approach. The simulation results illustrate that the proposed
controller is capable of overcoming disturbances and maintaining a
satisfactory tracking performance.
Abstract: In this work, stationary hot-wire measurements are
carried out to investigate the characteristics of a round free jet in its
potential core region (0 ≤ x/d ≤ 10). Measurements are carried out on
an incompressible round jet for a range of Reynolds numbers from
4000 to 8000, calculated based on the jet exit mean velocity and the
nozzle diameter. The effect of flow velocity on the development
characteristics of the jet in the core region is analyzed. Timeaveraged
statistics, spectra of velocity and its higher order moments
are presented and explained.
Abstract: A portable sensor for the analysis of phosphate in
aqueous samples has been developed. The sensor incorporates
microfluidic technology, colorimetric detection, and wireless
communications into a compact and rugged portable device. The
detection method used is the molybdenum yellow method, in which a
phosphate-containing sample is mixed with a reagent containing
ammonium metavanadate and ammonium molybdate in an acidic
medium. A yellow-coloured compound is generated and the
absorption of this compound is measured using a light emitting diode
(LED) light source and a photodiode detector. The absorption is
directly proportional to the phosphate concentration in the original
sample. In this paper we describe the application of this phosphate
sensor to the analysis of wastewater at a municipal wastewater
treatment plant in Co. Kildare, Ireland.
Abstract: This paper presents the results of preliminary
assessment of water quality along the coastal areas in the vicinity of
Left Bank Outfall Drainage (LBOD) and Tidal Link Drain (TLD) in
Sindh province after the cyclone 2A occurred in 1999. The water
samples were collected from various RDs of Tidal Link Drain and
lakes during September 2001 to April 2002 and were analysed for
salinity, nitrite, phosphate, ammonia, silicate and suspended material
in water. The results of the study showed considerable variations in
water quality depending upon the location along the coast in the
vicinity of LBOD and RDs. The salinity ranged between 4.39–65.25
ppt in Tidal Link Drain samples whereas 2.4–38.05 ppt in samples
collected from lakes. The values of suspended material at various
RDs of Tidal Link Drain ranged between 56.6–2134 ppm and at the
lakes between 68–297 ppm. The data of continuous monitoring at
RD–93 showed the range of PO4 (8.6–25.2 μg/l), SiO3 (554.96–1462
μg/l), NO2 (0.557.2–25.2 μg/l) and NH3 (9.38–23.62 μg/l). The
concentration of nutrients in water samples collected from different
RDs was found in the range of PO4 (10.85 to 11.47 μg/l), SiO3 (1624
to 2635.08 μg/l), NO2 (20.38 to 44.8 μg/l) and NH3 (24.08 to 26.6
μg/l). Sindh coastal areas which situated at the north-western
boundary the Arabian Sea are highly vulnerable to flood damages
due to flash floods during SW monsoon or impact of sea level rise
and storm surges coupled with cyclones passing through Arabian Sea
along Pakistan coast. It is hoped that the obtained data in this study
would act as a database for future investigations and monitoring of
LBOD and Tidal Link Drain coastal waters.
Abstract: In this paper, we give an overview of an online elearning
tool which has been developed for kids aged from nine to
eleven years old in Mauritius for the self-study of Mathematics in
order to prepare them for the CPE examination. The software does
not intend to render obsolete the existing pedagogical approaches.
Nowadays, the teaching-learning process is mainly focused towards
the class-room model. Moreover, most of the e-learning platforms
that exist are simply static ways of delivering resources using the
internet. There is nearly no interaction between the learner and the
tool. Our application will enable students to practice exercises online
and also work out sample examination papers. Another interesting
feature is that the kid will not have to wait for someone to correct the
work as the correction will be done online and on the spot. Additional
feedback is also provided for some exercises.
Abstract: Composite of Celatom-ZeoliteY (Cel-ZY) was used to
remove cobalt ion from an aqueous solution using batch mode.
ZeoliteY has successfully superimposed on Celatom FW-14 surface
using hydrothermal treatment .The product was synthesized as a
novel of hierarchical porous material. It was observed from the
results that Cel-ZY has higher ability to remove cobalt ions than the
pure ZeoliteY powder (PZY) synthesized under the same conditions.
Several parameters were studied in this project to investigate the
effect of removal cobalt ion such as pH and initial cobalt
concentration. It was clearly observed that the uptake of cobalt ions
was affected with increase these parameters. The results proved that
the product can be used effectively to remove Co2+ ions from
wastewater as an environmentally friendly alternative.
Abstract: In this study, the sorption of Malachite green (MG) on Hydrilla verticillata biomass, a submerged aquatic plant, was investigated in a batch system. The effects of operating parameters such as temperature, adsorbent dosage, contact time, adsorbent size, and agitation speed on the sorption of Malachite green were analyzed using response surface methodology (RSM). The proposed quadratic model for central composite design (CCD) fitted very well to the experimental data that it could be used to navigate the design space according to ANOVA results. The optimum sorption conditions were determined as temperature - 43.5oC, adsorbent dosage - 0.26g, contact time - 200min, adsorbent size - 0.205mm (65mesh), and agitation speed - 230rpm. The Langmuir and Freundlich isotherm models were applied to the equilibrium data. The maximum monolayer coverage capacity of Hydrilla verticillata biomass for MG was found to be 91.97 mg/g at an initial pH 8.0 indicating that the optimum sorption initial pH. The external and intra particle diffusion models were also applied to sorption data of Hydrilla verticillata biomass with MG, and it was found that both the external diffusion as well as intra particle diffusion contributes to the actual sorption process. The pseudo-second order kinetic model described the MG sorption process with a good fitting.
Abstract: Snow cover is an important phenomenon in
hydrology, hence modeling the snow accumulation and melting is an
important issue in places where snowmelt significantly contributes to
runoff and has significant effect on water balance. The physics-based
models are invariably distributed, with the basin disaggregated into
zones or grid cells. Satellites images provide valuable data to verify
the accuracy of spatially distributed model outputs. In this study a
spatially distributed physically based model (WetSpa) was applied to
predict snow cover and melting in the Latyan dam watershed in Iran.
Snowmelt is simulated based on an energy balance approach. The
model is applied and calibrated with one year of observed daily
precipitation, air temperature, windspeed, and daily potential
evaporation. The predicted snow-covered area is compared with
remotely sensed images (MODIS). The results show that simulated
snow cover area SCA has a good agreement with satellite image
snow cover area SCA from MODIS images. The model performance
is also tested by statistical and graphical comparison of simulated and
measured discharges entering the Latyan dam reservoir.
Abstract: A self-association model has been used to understand
the concentration dependence of free energy of mixing (GM), heat of
mixing (HM), entropy of mixing (SM), activity (a) and microscopic
structures, such as concentration fluctuation in long wavelength limit
(Scc(0)) and Warren-Cowley short range order parameter ( 1
α )for Cu-
Tl molten alloys at 1573K. A comparative study of surface tension of
the alloys in the liquid state at that temperature has also been carried
out theoretically as function of composition in the light of Butler-s
model, Prasad-s model and quasi-chemical approach. Most of the
computed thermodynamic properties have been found in agreement
with the experimental values. The analysis reveals that the Cu-Tl
molten alloys at 1573K represent a segregating system at all
concentrations with moderate interaction. Surface tensions computed
from different approaches have been found to be comparable to each
other showing increment with the composition of copper.
Abstract: In this study, the conversion of n-pentane to aromatics is investigated on HZSM-5 zeolites modified by Ga ion-exchange and silylation using tetraethyl orthosilicate (TEOS) via chemical liquid deposition (CLD). The effect of SiO2/Al2O3 ratios of HZSM-5 was also studied. Parameters in preparing catalysts i.e. TEOS loading and cycles of deposition were varied to obtain the optimal condition for enhancing p-xylene selectivity. The highest p-xylene selectivity 99.7% was achieved when the amount of TEOS was 20 vol.%.The catalysts were characterized by TPD, TPO, XRF, and BET. Results show that the conversion of n-pentane was influenced remarkably by the SiO2/Al2O3 ratios of HZSM-5. The highest p-xylene selectivity 99.7% was achieved when the amount of TEOS was 20 vol.%. And cycles of deposition greatly improves HZSM-5 shape-selectivity.
Abstract: In recent years, the number of natural disasters in the world has occurred frequently. After a strong earthquake occurs, multiple disasters due to tsunami, strong aftershocks or heavy snow can possible to occur. To prevent a secondary disaster and to save a life, the quick inspection of the damaged building is necessary. This paper investigated on a possibility of post earthquake quick inspection of damaged building by ordinary people which used the European Macro- Seismic Scale 1998 (EMS-98).
Abstract: benzo[b][1,4]oxazines have been synthesized in good
to excellent yields in the presence of the ionic liquid 1-butyl-3-
methylimidazolium bromide [bmim]Br under relatively mild
conditions without any added catalyst, the reaction workup is simple
and the ionic liquid can be easily separated from the product and
reused.
Abstract: In the crack growth analysis, the Stress Intensity
Factor (SIF) is a fundamental prerequisite. In the present study, the
mode I stress intensity factor (SIF) of three-dimensional penny-
Shaped crack is obtained in an isotropic elastic cylindrical medium
with arbitrary dimensions under arbitrary loading at the top of the
cylinder, by the semi-analytical method based on the Rayleigh-Ritz
method. This method that is based on minimizing the potential
energy amount of the whole of the system, gives a very close results
to the previous studies. Defining the displacements (elastic fields) by
hypothetical functions in a defined coordinate system is the base of
this research. So for creating the singularity conditions at the tip of
the crack the appropriate terms should be found.