Abstract: The asynchronous discussion forum is one of the most
widely used activities in learning management system environment.
Online forum allows participants to interact, construct knowledge,
and can be used to complement face to face sessions in blended
learning courses. However, to what extent do the students perceive
the benefits or advantages of forum remain to be seen. Through
content and social network analyses, instructors will be able to gauge
the students’ engagement and knowledge construction level. Thus,
this study aims to analyze the students’ level of knowledge
construction and their participation level that occur through online
discussion. It also attempts to investigate the relationship between the
level of knowledge construction and their social interaction patterns.
The sample involves 23 students undertaking a master course in one
public university in Malaysia. The asynchronous discussion forum
was conducted for three weeks as part of the course requirement. The
finding indicates that the level of knowledge construction is quite
low. Also, the density value of 0.11 indicating the overall
communication among the participants in the forum is low. This
study reveals that strong and significant correlations between SNA
measures (in-degree centrality, out-degree centrality) and level of
knowledge construction. Thus, allocating these active students in
different group aids the interactive discussion takes place. Finally,
based upon the findings, some recommendations to increase students’
level of knowledge construction and also for further research are
proposed.
Abstract: This experimental study aims at studying the
conversion of macro-algae into bioethanol under several steps of
procedure: preparation, pre-treatment, fermentation, and distillation.
The main objective of this work was to investigate the role of buffer’s
type as a stabiliser of pH level and fermentation time on the yield of
ethanol. For this purpose, experiments were carried out on biomass
macro-algae to de-couple the pre-treatment and fermentation
processes from those associated with distillation process. β-
glucosidase was used as cellulose decomposer during hydrolysis step
and yeast was used during fermentation process. The species of
macro-algae utilised as energy feedstock was Ulva lactuca and it was
harvested from southern coast of Central of Java Island – Indonesia.
Experiments were conducted in a simple fermenter over a different
buffer: citrate buffer and acetic buffer, and over a range of
fermentation times between 5 to 20 days. The ethanol production was
found to be significantly affected by both variables. The optimum
time of fermentation was 10 days with citrate buffer; result in
0.88458% of ethanol, and the ethanol content after distillation
process was shown 0.985015%.
Abstract: In this paper, snow samples containing dust particles
from several sampling points around the city of Ostrava were
analyzed. The pH values of sampled snow were measured and solid
particles analyzed. Particle size, zeta potential and content of selected
heavy metals were determined in solid particles. The pH values of
most samples lay in the slightly acid region. Mean values of particle
size ranged from 290.5 to 620.5 nm. Zeta potential values varied
between -5 and -26.5 mV. The following heavy metal concentration
ranges were found: copper 0.08-0.75 mg/g, lead 0.05-0.9 mg/g,
manganese 0.45-5.9 mg/g and iron 25.7-280.46 mg/g. The highest
values of copper and lead were found in the vicinity of busy
crossroads, and on the contrary, the highest levels of manganese and
iron were detected close to a large steelworks. The proportion
between pH values, zeta potentials, particle sizes and heavy metal
contents was established. Zeta potential decreased with rising pH
values and, simultaneously, heavy metal content in solid particles
increased. At the same time, higher metal content corresponded to
lower particle size.
Abstract: This paper explores the effects of gamification on
lower secondary school students’ motivation and engagement in the
classroom. Two-group posttest-only experimental design were
employed to study the influence of gamification teaching method
(GTM) when compared with conventional teaching method (CTM)
on 60 lower secondary school students. The Student Engagement
Instrument (SEI) and Intrinsic Motivation Inventory (IMI) were used
to assess students’ intrinsic motivation and engagement level towards
the respective teaching method. Finding indicates that students who
completed the GTM lesson were significantly higher in intrinsic
motivation to learn than those from the CTM. Although the result
were insignificant and only marginal difference in the engagement
mean, GTM still show better potential in raising student’s
engagement in class when compared with CTM. This finding proves
that the GTM is likely to solve the current issue of low motivation to
learn and low engagement in class among lower secondary school
students in Malaysia. On the other hand, despite being not significant,
higher mean indicates that CTM positively contribute to higher peer
support for learning and better teacher and student relationship when
compared with GTM. As a conclusion, gamification approach is
flexible and can be adapted into many learning content to enhance the
intrinsic motivation to learn and to some extent, encourage better
student engagement in class.
Abstract: Hot aqueous and methanol extracts of the two selected
herbal medicines such are Vellarugu chooranam (V.C) and
Amukkirai Chooranam (A.C) were examined for total phenolic and
flavonoid contents and in vitro antioxidant activity using four
different methods. The total phenolic and flavonoid contents in
methanol extract of V.C were found to be higher (44.41±1.26mg
GAE/g; 174.44±9.32mg QE/g) than in the methanol extract of A.C
(20.56±0.67mg GAE/g; 7.21±0.85mg QE/g). Hot methanol and
aqueous extracts of both medicines showed low antioxidant activity
in DPPH, ABTS, and FRAP methods and Iron chelating activity not
found at highest possible concentration. V.C contains higher
concentrations of total phenolic and flavonoid contents than A.C and
can also exert greater antioxidant activity than A.C, although the
activities demonstrated were lower than the positive control Trolox.
The in vitro antioxidant activity was not related with the total
phenolic and flavonoid contents of the methanol and aqueous extracts
of both herbal medicines (A.C and V.C).
Abstract: Health analytics (HA) is used in healthcare systems
for effective decision making, management and planning of
healthcare and related activities. However, user resistances, unique
position of medical data content and structure (including
heterogeneous and unstructured data) and impromptu HA projects
have held up the progress in HA applications. Notably, the accuracy
of outcomes depends on the skills and the domain knowledge of the
data analyst working on the healthcare data. Success of HA depends
on having a sound process model, effective project management and
availability of supporting tools. Thus, to overcome these challenges
through an effective process model, we propose a HA process model
with features from rational unified process (RUP) model and agile
methodology.
Abstract: Characterization of the engineering behavior of
unsaturated soil is dependent on the soil-water characteristic curve
(SWCC), a graphical representation of the relationship between water
content or degree of saturation and soil suction. A reasonable
description of the SWCC is thus important for the accurate prediction
of unsaturated soil parameters. The measurement procedures for
determining the SWCC, however, are difficult, expensive, and timeconsuming.
During the past few decades, researchers have laid a
major focus on developing empirical equations for predicting the
SWCC, with a large number of empirical models suggested. One of
the most crucial questions is how precisely existing equations can
represent the SWCC. As different models have different ranges of
capability, it is essential to evaluate the precision of the SWCC
models used for each particular soil type for better SWCC estimation.
It is expected that better estimation of SWCC would be achieved via
a thorough statistical analysis of its distribution within a particular
soil class. With this in view, a statistical analysis was conducted in
order to evaluate the reliability of the SWCC prediction models
against laboratory measurement. Optimization techniques were used
to obtain the best-fit of the model parameters in four forms of SWCC
equation, using laboratory data for relatively coarse-textured (i.e.,
sandy) soil. The four most prominent SWCCs were evaluated and
computed for each sample. The result shows that the Brooks and
Corey model is the most consistent in describing the SWCC for sand
soil type. The Brooks and Corey model prediction also exhibit
compatibility with samples ranging from low to high soil water
content in which subjected to the samples that evaluated in this study.
Abstract: Novel bio-based polymer electrolyte was synthesized
with LiClO4 as the main source of charge carrier. Initially,
polyurethane-LiClO4 polymer electrolytes were synthesized via
prepolymerization method with different NCO/OH ratios and labelled
them as PU1, PU2, PU3 and PU4. Fourier transform infrared (FTIR)
analysis indicates the co-ordination between Li+ ion and polyurethane
in PU1. Differential scanning calorimetry (DSC) analysis indicates
PU1 has the highest glass transition temperature (Tg) corresponds to
the most abundant urethane group which is the hard segment in PU1.
Scanning electron microscopy (SEM) shows the good miscibility
between lithium salt and the polymer. The study found that PU1
possessed the greatest ionic conductivity and the lowest activation
energy, Ea. All the polyurethanes exhibited linear Arrhenius
variations indicating ion transport via simple lithium ion hopping in
polyurethane. This research proves the NCO content in polyurethane
plays an important role in affecting the ionic conductivity of this
polymer electrolyte.
Abstract: In the present work, the effects of additives, including
contents of the added antioxidants and type of the selected metallic
stearates (either calcium stearate (CaSt) or zinc stearate (ZnSt)), on
the thermal stabilities of carbon black (CB)/high density polyethylene
(HDPE) compounds were studied. The results showed that the AO
contents played a key role in the thermal stabilities of the CB/HDPE
compounds — the higher the AO content, the higher the thermal
stabilities. Although the CaSt-containing compounds were slightly
superior to those with ZnSt in terms of the thermal stabilities, the
remaining solid residue of CaSt after heated to the temperature of 600
°C (mainly calcium carbonate (CaCO3) as characterized by the X-ray
diffraction (XRD) technique) seemed to catalyze the decomposition
of CB in the HDPE-based compounds. Hence, the quantification of
CB in the CaSt-containing compounds with a muffle furnace gave an
inaccurate CB content — much lower than actual value. However,
this phenomenon was negligible in the ZnSt-containing system.
Abstract: Information and Communication Technologies (ICTs)
are pervasive nowadays, including in education where they are
expected to improve the performance of learners. However, the hope
placed in ICTs to find viable solutions to the problem of poor
academic performance in schools in the developing world has not yet
yielded the expected benefits. This problem serves as a motivation to
this study whose aim is to examine the perceptions of educators on
the advantages and disadvantages of e-learning. This aim will be
subdivided into two types of research objectives. Objectives on the
identification and design of theories and models will be achieved
using content analysis and literature review. However, the objective
on the empirical testing of such theories and models will be achieved
through the survey of educators from different schools in the
Pinetown District of the South African Kwazulu-Natal province.
SPSS is used to quantitatively analyse the data collected by the
questionnaire of this survey using descriptive statistics and Pearson
correlations after assessing the validity and the reliability of the data.
The main hypothesis driving this study is that there is a relationship
between the demographics of educators’ and their adherence to
learning theories on one side, and their perceptions on the advantages
and disadvantages of e-learning on the other side, as argued by
existing research; but this research views these learning theories
under three perspectives: educators’ adherence to self-regulated
learning, to constructivism, and to progressivism. This hypothesis
was fully confirmed by the empirical study except for the
demographic factor where teachers’ level of education was found to
be the only demographic factor affecting the perceptions of educators
on the advantages and disadvantages of e-learning.
Abstract: In the present work, the effect of load and sliding
distance on the performance tribology of commercially used
aluminium-silicon engine block and piston was evaluated at ambient
conditions with humidity of 80% under dry sliding conditions using a
pin-on-disc with two different loads of 5N and 20N yielding applied
pressure of 0.30MPa and 1.4MPa, respectively, at sliding velocity of
0.29ms-1 and with varying sliding distance ranging from 260m-
4200m. Factors and conditions that had significant effect were
identified. The results showed that the load and the sliding distance
affect the wear rate of the alloys and the wear rate increased with
increasing load for both the alloys. Wear rate also increases almost
linearly at low loads and increase to a maximum then attain a plateau
with increasing sliding distance. For both applied loads the piston
alloy showed the better performance due to higher Ni and Mg
content. The worn surface and wear debris was characterized by
optical microscope, SEM and EDX analyzer. The worn surface was
characterized by surface with shallow grooves at loads while the
groove width and depth increased as the loads increases. Oxidative
wear was found to be the predominant mechanisms in the dry sliding
of Al-Si alloys at low loads.
Abstract: Calcium phosphate coating (CaP) has been employed
for protein delivery, but the typical direct protein adsorption on the
coating led to low incorporation content and fast release of the
protein from the coating. By using bovine serum albumin (BSA) as a
model protein, rapid biomimetic co-precipitation between calcium
phosphate and BSA was employed to control the distribution of BSA
within calcium phosphate coating during biomimetic formation on
titanium surface for only 6 h at 50oC in an accelerated calcium
phosphate solution. As a result, the amount of BSA incorporation and
release duration could be increased by using a rapid biomimetic coprecipitation
technique. Up to 43 fold increases in the BSA
incorporation content and the increase from 6 h to more than 360 h in
release duration compared to typical direct adsorption technique were
observed depending on the initial BSA concentration used during coprecipitation
(1, 10 and 100 μg.ml-1). From x-ray diffraction and
Fourier transform infrared spectroscopy studies, the coating
composition was not altered with the incorporation of BSA by this
rapid biomimetic co-precipitation and mainly comprised octacalcium
phosphate and hydroxyapatite. However, the microstructure of
calcium phosphate crystals changed from straight, plate-like units to
curved, plate-like units with increasing BSA content.
Abstract: Copper being one of the major intrinsic residual
impurities in steel possesses the tendency to induce severe
microstructural distortions if not controlled within certain limits.
Hence, this paper investigates the effect of this element on the
mechanical properties of construction steel with a view to ascertain
its safe limits for effective control. The experiment entails collection
of statistically scheduled samples of hot rolled profiles with varied
copper concentrations in the range of 0.12-0.39 wt. %. From these
samples were prepared standard test specimens subjected to tensile,
impact, hardness and microstructural analyses. Results show a rather
huge compromise in mechanical properties as the specimens
demonstrated 54.3%, 74.2% and 64.9% reduction in tensile strength,
impact energy and hardness respectively as copper content increases
from 0.12 wt. % to 0.39 wt. %. The steel’s abysmal performance is
due to the severe distortion of the microstructure occasioned by the
development of incoherent complex compounds which weaken the
pearlite reinforcing phase. It is concluded that the presence of copper
above 0.22 wt. % is deleterious to construction steel performance.
Abstract: This paper deals with the issue of biomass and sorted
municipal waste gasification and cogeneration using hot-air turbo-set.
It brings description of designed pilot plant with electrical output 80
kWe. The generated gas is burned in secondary combustion chamber
located beyond the gas generator. Flue gas flows through the heat
exchanger where the compressed air is heated and consequently
brought to a micro turbine. Except description, this paper brings our
basic experiences from operating of pilot plant (operating parameters,
contributions, problems during operating, etc.). The principal
advantage of the given cycle is the fact that there is no contact
between the generated gas and the turbine. So there is no need for
costly and complicated gas cleaning which is the main source of
operating problems in direct use in combustion engines because the
content of impurities in the gas causes operation problems to the units
due to clogging and tarring of working surfaces of engines and
turbines, which may lead as far as serious damage to the equipment
under operation. Another merit is the compact container package
making installation of the facility easier or making it relatively more
mobile. We imagine, this solution of cogeneration from biomass or
waste can be suitable for small industrial or communal applications,
for low output cogeneration.
Abstract: The reduction of greenhouse gases emissions is highly
discussed ecological theme at present. In addition to power industry
also main production sectors of binders, i.e. cement, air and hydraulic
lime are very sensitive to these questions. One of the possibilities
how CO2 emissions can be reduced directly at clinker burnout is
represented by partial substitution of lime with a material containing
limy ions at absence of carbonate group. Fluidised fly ash is one of
such potential raw materials where CaO can be found free and also
bound in anhydrite, CaSO4. At application of FBC (fluidized bed
combustion) fly ash with approximate 20% CaO content and its
dosing ratio to high percent lime 1:2, corresponding stechiometrically
to the preparation of raw material powder, approximately 0,37 t CO2
per 1 ton of one-component cement would be released at clinker
burnout compared to 0,46 t CO2 when orthodox raw materials are
used. The reduction of CO2 emissions thus could reach even 20%.
Abstract: The study area is Zaria, located in the basement
complex of northern Nigeria. The rock type forming the major part of
the Zaria batholith is granite. This research work was carried out to
compare the responses of seismic refraction tomography and
resistivity tomography in the same geologic environment and under
the same conditions. Hence, the choice of the site that has a visible
granitic outcrop that extends across a narrow stream channel and is
flanked by unconsolidated overburden, a neutral profile that was
covered by plain overburden and a site with thick lateritic cover
became necessary. The results of the seismic and resistivity
tomography models reveals that seismic velocity and resistivity does
not always simultaneously increase with depth, but their responses in
any geologic environment are determined by changes in the
mechanical and chemical content of the rock types rather than depth.
Abstract: The system is designed to show images which are
related to the query image. Extracting color, texture, and shape
features from an image plays a vital role in content-based image
retrieval (CBIR). Initially RGB image is converted into HSV color
space due to its perceptual uniformity. From the HSV image, Color
features are extracted using block color histogram, texture features
using Haar transform and shape feature using Fuzzy C-means
Algorithm. Then, the characteristics of the global and local color
histogram, texture features through co-occurrence matrix and Haar
wavelet transform and shape are compared and analyzed for CBIR.
Finally, the best method of each feature is fused during similarity
measure to improve image retrieval effectiveness and accuracy.
Abstract: Boron-gypsum is a waste which occurs in the boric
acid production process. In this study, the boron content of this waste
is evaluated for the use in synthesis of magnesium borates and such
evaluation of this kind of waste is useful more than storage or
disposal. Magnesium borates, which are a sub-class of boron
minerals, are useful additive materials for the industries due to their
remarkable thermal and mechanical properties. Magnesium borates
were obtained hydrothermally at different temperatures. Novelty of
this study is the search of the solution density effects to magnesium
borate synthesis process for the increasing the possibility of borongypsum
usage as a raw material. After the synthesis process, products
are subjected to XRD and FT-IR to identify and characterize their
crystal structure, respectively.
Abstract: Web search engines are designed to retrieve and
extract the information in the web databases and to return dynamic
web pages. The Semantic Web is an extension of the current web in
which it includes semantic content in web pages. The main goal of
semantic web is to promote the quality of the current web by
changing its contents into machine understandable form. Therefore,
the milestone of semantic web is to have semantic level information
in the web. Nowadays, people use different keyword- based search
engines to find the relevant information they need from the web.
But many of the words are polysemous. When these words are
used to query a search engine, it displays the Search Result Records
(SRRs) with different meanings. The SRRs with similar meanings are
grouped together based on Word Sense Disambiguation (WSD). In
addition to that semantic annotation is also performed to improve the
efficiency of search result records. Semantic Annotation is the
process of adding the semantic metadata to web resources. Thus the
grouped SRRs are annotated and generate a summary which
describes the information in SRRs. But the automatic semantic
annotation is a significant challenge in the semantic web. Here
ontology and knowledge based representation are used to annotate
the web pages.
Abstract: Despite four years of study in the tourism industry, the
Bachelor’s graduates cannot perform their jobs as experienced tour
guides. This research aimed to develop French teaching and studying
for Tourism with two main purposes: to analyze ‘Moves’ used in oral
presentations at tourist attraction; and to study content in guiding
presentations or 'Guide Speak'. The study employed audio recording
of these presentations as an interview method in authentic situations,
having four tour guides as respondents and information providers.
The data was analyzed via moves and content analysis. The results
found that there were eight Moves used; namely, Welcoming,
Introducing oneself, Drawing someone’s attention, Giving
information, Explaining, Highlighting, Persuading and Saying
goodbye. In terms of content, the information being presented
covered the outstanding characteristics of the places and wellintegrated
with other related content. The findings were used as
guidelines for curriculum development; in particular, the core content
and the presentation forming the basis for students to meet the
standard requirements of the labor-market and professional schemes.