Abstract: The biosynthesis of nanoparticles by microorganisms,
on the contrary to chemical synthesis, is an environmentally-friendly
process which has low energy requirements. In this investigation, we
used the microorganism Geobacillus wiegelii, strain GWE1, an
aerobic thermophile belonging to genus Geobacillus, isolated from a
drying oven. This microorganism has the ability to reduce selenite
evidenced by the change of color from colorless to red in the culture.
Elemental analysis and composition of the particles were verified
using transmission electron microscopy and energy-dispersive X-ray
analysis. The nanoparticles have a defined spherical shape and a
selenium elemental state. Previous experiments showed that the
presence of the whole microorganism for the reduction of selenite
was not necessary. The results strongly suggested that an intracellular
NADPH/NADH-dependent reductase mediates selenium
nanoparticles synthesis under aerobic conditions. The enzyme was
purified and identified by mass spectroscopy MALDI-TOF TOF
technique. The enzyme is a 1-pyrroline-5-carboxylate dehydrogenase.
Histograms of nanoparticles sizes were obtained. Size distribution
ranged from 40-160 nm, where 70% of nanoparticles have less than
100 nm in size. Spectroscopic analysis showed that the nanoparticles
are composed of elemental selenium. To analyse the effect of pH in
size and morphology of nanoparticles, the synthesis of them was
carried out at different pHs (4.0, 5.0, 6.0, 7.0, 8.0). For
thermostability studies samples were incubated at different
temperatures (60, 80 and 100 ºC) for 1 h and 3 h. The size of all
nanoparticles was less than 100 nm at pH 4.0; over 50% of
nanoparticles have less than 100 nm at pH 5.0; at pH 6.0 and 8.0 over
90% of nanoparticles have less than 100 nm in size. At neutral pH
(7.0) nanoparticles reach a size around 120 nm and only 20% of them
were less than 100 nm. When looking at temperature effect,
nanoparticles did not show a significant difference in size when they
were incubated between 0 and 3 h at 60 ºC. Meanwhile at 80 °C the
nanoparticles suspension lost its homogeneity. A change in size was
observed from 0 h of incubation at 80ºC, observing a size range
between 40-160 nm, with 20% of them over 100 nm. Meanwhile
after 3 h of incubation at size range changed to 60-180 nm with 50%
of them over 100 nm. At 100 °C the nanoparticles aggregate forming
nanorod structures. In conclusion, these results indicate that is
possible to modulate size and shape of biologically synthesized
nanoparticles by modulating pH and temperature.
Abstract: The aim of the present work was to statistically design
an autotrophic medium for maximum biomass production by
Chlorella pyrenoidosa using response surface methodology. After
evaluating one factor at a time approach, K2HPO4, KNO3,
MgSO4.7H2O and NaHCO3 were preferred over the other
components of the fog’s medium as most critical autotrophic medium
components. The study showed that the maximum biomass yield was
achieved while the concentrations of MgSO4.7H2O, K2HPO4, KNO3
and NaHCO3 were 0.409 g/L, 0.24 g/L, 1.033 g/L, and 3.265 g/L,
respectively. The study reported that the biomass productivity of C.
pyrenoidosa improved from 0.14 g/L in defined fog’s medium to 1.40
g/L in modified fog’s medium resulting 10 fold increase. The
biochemical composition biosynthesis of C. pyrenoidosa was altered
using nitrogen limiting stress bringing about 5.23 fold increase in
lipid content than control (cell without stress), as analyzed by FTIR
integration method.
Abstract: The purpose of this study was to investigate
perceptions of climate change risk to forest ecosystems and forestbased
communities as well as perceived effectiveness of adaptation
strategies for climate change as well as challenges for adaptation.
Data was gathered using a pre-tested semi-structured questionnaire.
Simple random selection technique was applied. For the majority of
issues, the responses were obtained on multi-point likert scales, and
the scores provided were, in turn, used to estimate the means and
other useful estimates. A composite knowledge index developed
using correct responses to a set of self-rated statements were used to
evaluate the issues. The mean of the knowledge index was 0.64. Also
all respondents recorded values of the knowledge index above 0.25.
Increase forest fire was perceived by respondents as the greatest risk
to forest eco-system. Decrease access to water supplies was perceived
as the greatest risk to livelihoods of forest based communities. The
most effective adaptation strategy relevant to climate change risks to
forest eco-systems and forest based communities livelihoods in
Kathmandu valley in Nepal as perceived by the respondents was
reforestation and afforestation. As well, lack of public awareness was
perceived as the major limitation for climate change adaptation.
However, perceived risks as well as effective adaptation strategies
showed an inconsistent association with knowledge indicators and
social-cultural variables. The results provide useful information to
any party who involve with climate change issues in Nepal, since
such attempts would be more effective once the people’s perceptions
on these aspects are taken into account.
Abstract: Background: Bleeding during first half of pregnancy
mostly originates from placenta, some abort, others are at risk of
complications. Objective: Study was done to know perinatal outcome
with bleeding up to 20 weeks in singleton pregnancy. Material
Methods: Subjects were 1020, equal controls managed over 2 years,
435 had viable pregnancy at admission, 135 excluded, 300 followed
for perinatal outcome, 99 (19.52% up to 10 weeks), 201 (39.18% of
11-20 weeks). Results: Hypertensive disorders occurred in 24% cases
of bleeding within 10 weeks, 22% 11-20 weeks 14.79% controls,
placenta previa 4% in 10 weeks, 0.9% 11-20 weeks, 0.97% controls,
prelabor rupture of membranes in 16%, 7.45% controls. 20% up to 10
weeks, 35% 11-20 weeks, 18% controls had fetal growth restriction,
34.34% up to 10 weeks 30.35% of 11-20 weeks 17.17% controls had
preterm births, perinatal mortality rate in study was 118.62, in
controls 68.16 (Uneventful pregnancy in 13.52% study, 46.11%
controls). Conclusion: Once bleeding occurs, one third continue
pregnancy, maternal neonatal outcome gets affected with variations
in cases of bleeding within first 10 weeks & 11-20 weeks.
Abstract: This paper contains 2 main parts. In the first part of paper we simulated and studied three types of electrode patterns used in various industries for suspension and handling of the semiconductor and glass and we selected the best pattern by evaluating the electrostatic force, which was comb pattern electrode.
In the second part we investigated the parameters affecting the amount of electrostatic force such as the gap between surface and electrode (g), the electrode width (w), the gap between electrodes (t), the surface permittivity and electrode length and methods of improvement of adhesion force by changing these values.
Abstract: The objective of the Economic Dispatch(ED) Problems
of electric power generation is to schedule the committed generating
units outputs so as to meet the required load demand at minimum
operating cost while satisfying all units and system equality and
inequality constraints. This paper presents a new method of ED
problems utilizing the Max-Min Ant System Optimization.
Historically, traditional optimizations techniques have been used,
such as linear and non-linear programming, but within the past
decade the focus has shifted on the utilization of Evolutionary
Algorithms, as an example Genetic Algorithms, Simulated Annealing
and recently Ant Colony Optimization (ACO). In this paper we
introduce the Max-Min Ant System based version of the Ant System.
This algorithm encourages local searching around the best solution
found in each iteration. To show its efficiency and effectiveness, the
proposed Max-Min Ant System is applied to sample ED problems
composed of 4 generators. Comparison to conventional genetic
algorithms is presented.
Abstract: Software reusability is an essential characteristic of
Component-Based Software (CBS). The component reusability is an
important assess for the effective reuse of components in CBS. The
attributes of reusability proposed by various researchers are studied
and four of them are identified as potential factors affecting
reusability. This paper proposes metric for reusability estimation of
black-box software component along with metrics for Interface
Complexity, Understandability, Customizability and Reliability. An
experiment is performed for estimation of reusability through a case
study on a sample web application using a real world component.
Abstract: Distributed Generation (DG) can help in reducing the
cost of electricity to the costumer, relieve network congestion and
provide environmentally friendly energy close to load centers. Its
capacity is also scalable and it provides voltage support at distribution
level. Hence, DG placement and penetration level is an important
problem for both the utility and DG owner. DG allocation and capacity
determination is a nonlinear optimization problem. The objective
function of this problem is the minimization of the total loss of the
distribution system. Also high levels of penetration of DG are a new
challenge for traditional electric power systems. This paper presents a
new methodology for the optimal placement of DG and penetration
level of DG in distribution system based on General Algebraic
Modeling System (GAMS) and Genetic Algorithm (GA).
Abstract: A series of polystyrene (PS) nanoparticles were
prepared by grafting polystyrene from both aggregated silica and
colloidally dispersed silica nanoparticles using atom-transfer radical
polymerisation (ATRP). Cross-linking and macroscopic gelation
were minimised by using a miniemulsion system. The thermal and
mechanical behaviour of the nanocomposites have been examined by
differential scanning calorimetry (DSC) and dynamic mechanical
thermal analysis (DMTA).
Abstract: Inland Waterway Transportation (IWT) is playing an
important role in national transport systems, water transportation is
considered to be safe, energy efficient and environmentally friendly
mode of transport, all benefits of IWT cause national awareness
increase, for instance the Colombian government is planning to
restore the navigability of the most important river of the country, the
Magdalena’s River navigability, embrace waterway transportation in
Colombia could strength competitiveness while reduce most of the
transport externalities. However, the current situation of the
Magdalena is deplorable, the most important river of Colombia has
been abandoned for decades and the solution is beyond of a single
administrative entity. This paper analyzes the outcomes of the
Navigation And Inland Waterway Action and Development in
Europe program (NAIADES) as a prospective to develop a similar
program in Colombia with similar objectives and guidelines,
considering sustainability, guarantying the long-term future results
and adaptability of the program. Identifying stakeholders and policy
experts, a set of individual interviews were carried out; findings
support the idea of lack of integration within governmental
institutions and lack of importance in marketing promotion as
possible drawbacks on the implementation of IWT projects.
Abstract: South Africa has some regions which are susceptible
to moderate seismic activity. A peak ground acceleration of between
0.1g and 0.15g can be expected in the southern parts of the Western
Cape. Unreinforced Masonry (URM) is commonly used as a
construction material for 2 to 5 storey buildings in underprivileged
areas in and around Cape Town. URM is typically regarded as the
material most vulnerable to damage when subjected to earthquake
excitation. In this study, a three-storey URM building was analysed
by applying seven earthquake time-histories, which can be expected
to occur in South Africa using a finite element approach.
Experimental data was used to calibrate the in- and out-of-plane
stiffness of the URM. The results indicated that tensile cracking of
the in-plane piers was the dominant failure mode. It is concluded that
URM buildings of this type are at risk of failure especially if
sufficient ductility is not provided. The results also showed that
connection failure must be investigated further.
Abstract: Pavement surface unevenness plays a pivotal role on
roughness index of road which affects on riding comfort ability.
Comfort ability refers to the degree of protection offered to vehicle
occupants from uneven elements in the road surface. So, it is
preferable to have a lower roughness index value for a better riding
quality of road users. Roughness is generally defined as an
expression of irregularities in the pavement surface which can be
measured using different equipments like MERLIN, Bump integrator,
Profilometer etc. Among them Bump Integrator is quite simple and
less time consuming in case of long road sections. A case study is
conducted on low volume roads in West District in Tripura to
determine roughness index (RI) using Bump Integrator at the
standard speed of 32 km/h. But it becomes too tough to maintain the
requisite standard speed throughout the road section. The speed of
Bump Integrator (BI) has to lower or higher in some distinctive
situations. So, it becomes necessary to convert these roughness index
values of other speeds to the standard speed of 32 km/h. This paper
highlights on that roughness index conversional model. Using SPSS
(Statistical Package of Social Sciences) software a generalized
equation is derived among the RI value at standard speed of 32 km/h
and RI value at other speed conditions.
Abstract: Paper presents a study about dynamic effects obtained
from the dynamic load testing of the city highway bridges in Latvia
carried out from 2005 to 2012. 9 prestressed concrete bridges and 4
composite bridges were considered. 11 of 13 bridges were designed
according to the Eurocodes but two according to the previous
structural codes used in Latvia (SNIP 2.05.03-84). The dynamic
properties of the bridges were obtained by heavy vehicle passing the
bridge roadway with different driving speeds and with or without
even pavement. The obtained values of the Dynamic amplification
factor (DAF) and the bridge natural frequency were analyzed and
compared to the values of built-in traffic load models provided in
Eurocode 1. The actual DAF values for even bridge pavement in the
most cases are smaller than the value adopted in Eurocode 1. Vehicle
speed for uneven pavements significantly influence Dynamic
amplification factor values.
Abstract: This paper discusses about the findings of preliminary
survey on MATLAB software learning among power electronics
students. One of the main focuses of power electronics course is on
DC to DC boost convertors, because boost convertors are generally
used in different industrial and non industrial applications. Population
samples of this study were randomly selected final year bachelor of
electronics and electrical engineering students from University Tun
Hussein Onn Malaysia (UTHM).As per the results from the survey
questioner analysis, almost eighty percent students are facing
problem and difficulties in Dc to Dc boost convertors experimental
understanding without using MATLAB simulink package. As per
finding of this study it is clear that MATLAB play an effective and
efficient function for better understanding of boost convertors
experimental work among power electronics learners.
Abstract: This study offers a comprehensive review of the
research papers published in the field of cooling towers and gives an
insight into the latest developments of the natural draught cooling
towers. Different modeling, analysis and design techniques are
summarized and the challenges are discussed. The 118 references
included in this paper are mostly concentrated on the review of the
published papers after 2005. The present paper represents a complete
collection of the studies done for cooling towers and would give an
updated material for the researchers and design engineers in the field
of hyperbolic cooling towers.
Abstract: A computational fluid dynamics simulation is done for
non-Newtonian fluid in a baffled stirred tank. The CMC solution is
taken as non-Newtonian shear thinning fluid for simulation. The
Reynolds Average Navier Stocks equation with steady state multi
reference frame approach is used to simulate flow in the stirred tank.
The turbulent flow field is modelled using realizable k-ε turbulence
model. The simulated velocity profiles of Rushton turbine is
validated with literature data. Then, the simulated flow field of CD-6
impeller is compared with the Rushton turbine. The flow field
generated by CD-6 impeller is less in magnitude than the Rushton
turbine. The impeller global parameter, power number and flow
number, and entropy generation due to viscous dissipation rate is also
reported.
Abstract: Curcuma longa L. (Zingiberaceae), commonly known
as turmeric, has a long history of traditional uses for culinary
purposes as a spice and a food colorant. The present study aimed to
document the ethnobotanical knowledge about Curcuma longa, and
to assess the variation in the herbalists’ experience in Northeastern
Algeria. Data were collected using semi-structured questionnaires
and direct interviews with 30 herbalists. Ethnobotanical indices,
including the fidelity level (FL%), the relative frequency citation
(RFC), and use value (UV) were determined by quantitative methods.
Diversity in the level of knowledge was analyzed using univariate,
non-parametric, and multivariate statistical methods. Three main
categories of uses were recorded for C. longa: for food, for medicine,
and for cosmetic purposes. As a medicine, turmeric was used for the
treatment of gastrointestinal, dermatological, and hepatic diseases.
Medicinal and food uses were correlated with both forms of
preparation (rhizome and powder). The age group did not influence
the use. Multivariate analyses showed a significant variation in
traditional knowledge, associated with the use value, origin, quality,
and efficacy of the drug. The findings suggested that the geographical
origin of C. longa affected the use in Algeria.
Abstract: The use of information and communication
technologies such as computers, mobile phones and the Internet is
becoming prevalent in today’s world; and it is facilitating access to a
vast amount of data, services and applications for the improvement of
people’s lives. However, this prevalence of ICTs is hampered by the
problem of low income levels in developing countries to the point
where people cannot timeously replace or repair their ICT devices
when damaged or lost; and this problem serves as a motivation for
this study whose aim is to examine the perceptions of teachers on the
reliability of cellphones when used for teaching and learning
purposes. The research objectives unfolding this aim are of two
types: Objectives on the selection and design of theories and models,
and objectives on the empirical testing of these theories and models.
The first type of objectives is achieved using content analysis in an
extensive literature survey: and the second type of objectives is
achieved through a survey of high school teachers from the ILembe
and UMgungundlovu districts in the KwaZulu-Natal province of
South Africa. Data collected from this questionnaire based survey is
analysed in SPSS using descriptive statistics and Pearson correlations
after checking the reliability and validity of the questionnaires. The
main hypothesis driving this study is that there is a relationship
between the demographics and the attribution identity of teachers on
one hand, and their perceptions on the reliability of cellphones on the
other hand, as suggested by existing literature; except that attribution
identities are considered in this study under three angles: intention,
knowledge and ability, and action. The results of this study confirm
that the perceptions of teachers on the reliability of cellphones for
teaching and learning are affected by the school location of these
teachers, and by their perceptions on learners’ cellphones usage
intentions and actual use.
Abstract: The handwriting is a physical demonstration of a
complex cognitive process learnt by man since his childhood. People
with disabilities or suffering from various neurological diseases are
facing so many difficulties resulting from problems located at the
muscle stimuli (EMG) or signals from the brain (EEG) and which
arise at the stage of writing. The handwriting velocity of the same
writer or different writers varies according to different criteria: age,
attitude, mood, writing surface, etc. Therefore, it is interesting to
reconstruct an experimental basis records taking, as primary
reference, the writing speed for different writers which would allow
studying the global system during handwriting process. This paper
deals with a new approach of the handwriting system modeling based
on the velocity criterion through the concepts of artificial neural
networks, precisely the Radial Basis Functions (RBF) neural
networks. The obtained simulation results show a satisfactory
agreement between responses of the developed neural model and the
experimental data for various letters and forms then the efficiency of
the proposed approaches.
Abstract: A novel method to produce a fast high voltage solid
states switch using Insulated Gate Bipolar Transistors (IGBTs) is
presented for discharge-pumped gas lasers. The IGBTs are connected
in series to achieve a high voltage rating. An avalanche transistor is
used as the gate driver. The fast pulse generated by the avalanche
transistor quickly charges the large input capacitance of the IGBT,
resulting in a switch out of a fast high-voltage pulse. The switching
characteristic of fast-high voltage solid state switch has been estimated
in the multi-stage series-connected IGBT with the applied voltage of
several tens of kV. Electrical circuit diagram and the mythology of
fast-high voltage solid state switch as well as experimental results
obtained are presented.