Abstract: Lyophilization, also called freeze-drying, is an
important dehydration technique mainly used for pharmaceuticals.
Food industry also uses lyophilization when it is important to retain
most of the nutritional quality, taste, shape and size of dried products
and to extend their shelf life. Vacuum-Induced during freezing cycle
(VI) has been used in order to control ice nucleation and,
consequently, to reduce the time of primary drying cycle of
pharmaceuticals preserving quality properties of the final product.
This procedure has not been applied in freeze drying of foods. The
present work aims to investigate the effect of VI on the lyophilization
drying time, final moisture content, density and reconstitutional
properties of mango (Mangifera indica L.) slices (MS) and mango
pulp-maltodextrin dispersions (MPM) (30% concentration of total
solids). Control samples were run at each freezing rate without using
induced vacuum. The lyophilization endpoint was the same for all
treatments (constant difference between capacitance and Pirani
vacuum gauges). From the experimental results it can be concluded
that at the high freezing rate (0.4°C/min) reduced the overall process
time up to 30% comparing process time required for the control and
VI of the lower freeze rate (0.1°C/min) without affecting the quality
characteristics of the dried product, which yields a reduction in costs
and energy consumption for MS and MPM freeze drying. Controls
and samples treated with VI at freezing rate of 0.4°C/min in MS
showed similar results in moisture and density parameters.
Furthermore, results from MPM dispersion showed favorable values
when VI was applied because dried product with low moisture
content and low density was obtained at shorter process time
compared with the control. There were not found significant
differences between reconstitutional properties (rehydration for MS
and solubility for MPM) of freeze dried mango resulting from
controls, and VI treatments.
Abstract: High moisture content in fruits generates post-harvest
problems such as mechanical, biochemical, microbial and physical
losses. Dehydration, which is based on the reduction of water activity
of the fruit, is a common option for overcoming such losses.
However, regular hot air drying could affect negatively the quality
properties of the fruit due to the long residence time at high
temperature. Power ultrasound (US) application during the
convective drying has been used as a novel method able to enhance
drying rate and, consequently, to decrease drying time. In the present
study, a new approach was tested to evaluate the effect of US on the
drying time, the final antioxidant activity (AA) and the total
polyphenol content (TPC) of banana slices (BS), mango slices (MS)
and guava slices (GS). There were also studied the drying kinetics
with nine different models from which water effective diffusivities
(Deff) (with or without shrinkage corrections) were calculated.
Compared with the corresponding control tests, US assisted drying
for fruit slices showed reductions in drying time between 16.23 and
30.19%, 11.34 and 32.73%, and 19.25 and 47.51% for the MS, BS
and GS respectively. Considering shrinkage effects, Deff calculated
values ranged from 1.67*10-10 to 3.18*10-10 m2/s, 3.96*10-10 and
5.57*10-10 m2/s and 4.61*10-10 to 8.16*10-10 m2/s for the BS, MS and
GS samples respectively. Reductions of TPC and AA (as DPPH)
were observed compared with the original content in fresh fruit data
in all kinds of drying assays.
Abstract: In this paper, we describe the use of formal methods
to model malware behaviour. The modelling of harmful behaviour
rests upon syntactic structures that represent malicious procedures
inside malware. The malicious activities are modelled by a formal
grammar, where API calls’ components are the terminals and the set
of API calls used in combination to achieve a goal are designated
non-terminals. The combination of different non-terminals in various
ways and tiers make up the attack vectors that are used by harmful
software. Based on these syntactic structures a parser can be
generated which takes execution traces as input for pattern
recognition.
Abstract: The current-voltage (I-V) characteristics of Pd/n-GaN Schottky barrier were studied at temperatures over room temperature (300-470K). The values of ideality factor (n), zero-bias barrier height (φB0), flat barrier height (φBF) and series resistance (Rs) obtained from I-V-T measurements were found to be strongly temperature dependent while (φBo) increase, (n), (φBF) and (Rs) decrease with increasing temperature. The apparent Richardson constant was found to be 2.1x10-9 Acm-2K-2 and mean barrier height of 0.19 eV. After barrier height inhomogeneities correction, by assuming a Gaussian distribution (GD) of the barrier heights, the Richardson constant and the mean barrier height were obtained as 23 Acm-2K-2 and 1.78eV, respectively. The corrected Richardson constant was very closer to theoretical value of 26 Acm-2K-2.
Abstract: Radiative heat transfer in participating medium was
carried out using the finite volume method. The radiative transfer
equations are formulated for absorbing and anisotropically scattering
and emitting medium. The solution strategy is discussed and the
conditions for computational stability are conferred. The equations
have been solved for transient radiative medium and transient
radiation incorporated with transient conduction. Results have been
obtained for irradiation and corresponding heat fluxes for both the
cases. The solutions can be used to conclude incident energy and
surface heat flux. Transient solutions were obtained for a slab of heat
conducting in slab and by thermal radiation. The effect of heat
conduction during the transient phase is to partially equalize the
internal temperature distribution. The solution procedure provides
accurate temperature distributions in these regions. A finite volume
procedure with variable space and time increments is used to solve
the transient radiation equation. The medium in the enclosure
absorbs, emits, and anisotropically scatters radiative energy. The
incident radiations and the radiative heat fluxes are presented in
graphical forms. The phase function anisotropy plays a significant
role in the radiation heat transfer when the boundary condition is
non-symmetric.
Abstract: Structural analysis of flexible pavements has been and still is currently performed using multi-layer elastic theory. However, for thinly surfaced pavements subjected to low to medium volumes of traffics, the importance of non-linear stress-strain behavior of unbound granular materials (UGM) requires the use of more sophisticated numerical models for structural design and performance of such pavements. In the present work, nonlinear unbound aggregates constitutive model is implemented within an axisymmetric finite element code developed to simulate the nonlinear behavior of pavement structures including two local aggregates of different mineralogical nature, typically used in Algerian pavements. The performance of the mechanical model is examined about its capability of representing adequately, under various conditions, the granular material non-linearity in pavement analysis. In addition, deflection data collected by Falling Weight Deflectometer (FWD) are incorporated into the analysis in order to assess the sensitivity of critical pavement design criteria and pavement design life to the constitutive model. Finally, conclusions of engineering significance are formulated.
Abstract: A novel Active Flap System (AFS) has been developed
at DTU Wind Energy, as a result of a 3-year R&D project following
almost 10 years of innovative research in this field. The full scale AFS
comprises an active deformable trailing edge has been tested at the
unique rotating test facility at the Risø Campus of DTU Wind Energy
in Denmark. The design and instrumentation of the wing section and
the AFS are described. The general description and objectives of the
rotating test rig at the Risø campus of DTU are presented, along
with an overview of sensors on the setup and the test cases. The
post-processing of data is discussed and results of steady, flap step
and azimuth control flap cases are presented.
Abstract: The purpose of this research was to investigate the
creep behaviour of the heterogeneous Timber-UHPFRC beams. New
developments have been done to further improve the structural
performance, such as strengthening of the timber (glulam) beam by
bonding composite material combine with an ultra-high performance
fibre reinforced concrete (UHPFRC) internally reinforced with or
without carbon fibre reinforced polymer (CFRP) bars. However, in
the design of wooden structures, in addition to the criteria of
strengthening and stiffness, deformability due to the creep of wood,
especially in horizontal elements, is also a design criterion. Glulam,
UHPFRC and CFRP may be an interesting composite mix to respond
to the issue of creep behaviour of composite structures made of
different materials with different rheological properties. In this paper,
we describe an experimental and analytical investigation of the creep
performance of the glulam-UHPFRC-CFRP beams assembled by
bonding. The experimental investigations creep behaviour was
conducted for different environments: in- and outside under constant
loading for approximately a year. The measured results are compared
with numerical ones obtained by an analytical model. This model was
developed to predict the creep response of the glulam-UHPFRCCFRP
beams based on the creep characteristics of the individual
components. The results show that heterogeneous glulam-UHPFRC
beams provide an improvement in both the strengthening and
stiffness, and can also effectively reduce the creep deflection of
wooden beams.
Abstract: In VLSI, testing plays an important role. Major
problem in testing are test data volume and test power. The important
solution to reduce test data volume and test time is test data
compression. The Proposed technique combines the bit maskdictionary
and 2n pattern run length-coding method and provides a
substantial improvement in the compression efficiency without
introducing any additional decompression penalty. This method has
been implemented using Mat lab and HDL Language to reduce test
data volume and memory requirements. This method is applied on
various benchmark test sets and compared the results with other
existing methods. The proposed technique can achieve a compression
ratio up to 86%.
Abstract: One of the fundamental characteristics of Information
and Communication Technology (ICT) has been the ever-changing
nature of continuous release and models of ICTs with its impact on
the academic, social, and psychological benefits of its introduction in
schools. However, there seems to be a growing concern about its
negative impact on students when introduced early in schools for
teaching and learning. This study aims to design a model of child
development factors affecting the early introduction of ICTs in
schools in an attempt to improve the understanding of child
development and introduction of ICTs in schools. The proposed
model is based on a sound theoretical framework. It was designed
following a literature review of child development theories and child
development factors. The child development theoretical framework
that fitted to the best of all child development factors was then chosen
as the basis for the proposed model. This study hence found that the
Jean Piaget cognitive developmental theory is the most adequate
theoretical frameworks for modeling child development factors for
ICT introduction in schools.
Abstract: Main purpose of this study is to identify the impact of
government expenditure on economic growth in Asian Countries.
Consequently, main objective is to analyze whether government
expenditure causes economic growth in Asian countries vice versa
and then scrutinizing long-run equilibrium relationship exists
between them. The study completely based on secondary data. The
methodology being quantitative that includes econometrical
techniques of cointegration, panel fixed effects model and granger
causality in the context of panel data of Asian countries; Singapore,
Malaysia, Thailand, South Korea, Japan, China, Sri Lanka, India and
Bhutan with 44 observations in each country, totaling to 396
observations from 1970 to 2013. The model used is the random
effects panel OLS model. As with the above methodology, the study
found the fascinating outcome. At first, empirical findings exhibit a
momentous positive impact of government expenditure on Gross
Domestic Production in Asian region. Secondly, government
expenditure and economic growth indicate a long-run relationship in
Asian countries. In conclusion, there is a unidirectional causality
from economic growth to government expenditure and government
expenditure to economic growth in Asian countries. Hence the study
is validated that it is in line with the Keynesian theory and Wagner’s
law as well. Consequently, it can be concluded that role of
government would play a vital role in economic growth of Asian
Countries. However; if government expenditure did not figure out
with the economy’s needs it might be considerably inspiration the
economy in a negative way so that society bears the costs.
Abstract: In this paper we studied sono catalytic oxidative desulfurization of oil and diesel fraction from “Zhanazhol” oil deposits. We have established that the combined effect of the ultrasonic field and oxidant (ozone-air mixture) in the presence of the catalyst on the oil is potentially very effective method of desulfurization of oil and oil products. This method allows increasing the degree of desulfurization of oil by 62%.
Abstract: A multilayer passive shield composed of low-activity
lead (Pb), copper (Cu), tin (Sn) and iron (Fe) was designed and
manufactured for a coaxial HPGe detector placed at a surface
laboratory for reducing background radiation and radiation dose to
the personnel. The performance of the shield was evaluated and
efficiency curves of the detector were plotted by using of various
standard sources in different distances. Monte Carlo simulations and
a set of TLD chips were used for dose estimation in two distances of
20 and 40 cm. The results show that the shield reduced background
spectrum and the personnel dose more than 95%.
Abstract: The present study is a functional analysis of the
relationship between castes which indicates the dynamics of the caste
structure in the rural setting. The researcher has tried to show both
the cooperation and competition on important ceremonial and social
occasions. The real India exists in the villages, so we need to know
about their solidarity and also what the village life is and has been
shaping into. We need to emphasize a microcosmic study of Indian
rural life. Furthermore, caste integration is an acute problem country
faces today. To resolve this we are required to know the dynamics of
behavior of the people of different castes and for the study of the
caste dynamics a study of caste relations are needed. The present
study is an attempt in this direction.
Abstract: The fuel potential of six tropical hardwood species
namely: Triplochiton scleroxylon, Ceiba pentandra, Aningeria
robusta, Terminalia superba, Celtis mildbreadii and Piptadenia
africana were studied. Properties studied included species density,
gross calorific value, volatile matter, ash content, organic carbon and
elemental composition. Fuel properties were determined using
standard laboratory methods. The result indicates that the gross
calorific value (GCV) of the species ranged from 20.16 to 22.22
MJ/kg and they slightly varied from each other. Additionally, the
GCV of the biomass materials were higher than that of other biomass
materials like; wheat straw, rice straw, maize straw and sugar cane.
The ash and volatile matter content varied from 0.6075 to 5.0407%,
and 75.23% to 83.70% respectively. The overall rating of the
properties of the six biomass materials suggested that Piptadenia
africana has the best fuel property to be used as briquettes and
Aningeria robusta the worse. This study therefore suggests that a
holistic assessment of a biomass material needs to be done before
selecting it for fuel purpose.
Abstract: The research aims to study the association between
job satisfaction, motivation and the five factors of organizational
citizenship behavior (i.e. Altruism, Conscientiousness,
Sportsmanship, Courtesy and Civic virtue) among Public Sector
Employees in Pakistan. In this research Structure Equation Modeling
with confirmatory factor analysis was used to test the relationship
between two independent and five dependent variables. Data was
collected through questionnaire survey from 152 Public Servants
Working in Gujrat District-Pakistan in different capacities. Stratified
Random Sampling Technique was used to conduct this survey. The
results of the study indicate that five factors of OCB have positive
significant relation with both motivation and job satisfaction except
the relationship of Civic Virtue with Motivation. The research
findings implicate that factors other than motivation and job
satisfaction may also affect OCB. Likewise, all the five factors of
OCB may not be present in all populations. Thus, Managers must
concentrate on increasing motivation and job satisfaction to increase
OCB. Furthermore, the present research gives a direction to future
researchers to use more independent variables (e.g. Culture,
leadership, workplace environment, various job attitudes, types of
motivation, etc.) on different types of populations with larger sample
size in order to find the reasons behind insignificant relationship of
civic virtue with Motivation in the research in hand and to generalize
the tested model.
Abstract: Multiple-input multiple-output (MIMO) radar has
received increasing attention in recent years. MIMO radar has many
advantages over conventional phased array radar such as target
detection,resolution enhancement, and interference suppression. In
this paper, the results are presented from a simulation study of MIMO
uniformly-spaced linear array (ULA) antennas. The performance is
investigated under varied parameters, including varied array size,
pseudo random (PN) sequence length, number of snapshots, and
signal to noise ratio (SNR). The results of MIMO are compared to a
traditional array antenna.
Abstract: Mobile Ad Hoc Networks (MANETs) is a collection
of mobile devices forming a communication network without
infrastructure. MANET is vulnerable to security threats due to
network’s limited security, dynamic topology, scalability and the lack
of central management. The Quality of Service (QoS) routing in such
networks is limited by network breakage caused by node mobility or
nodes energy depletions. The impact of node mobility on trust
establishment is considered and its use to propagate trust through a
network is investigated in this paper. This work proposes an
enhanced Associativity Based Routing (ABR) with Fuzzy based
Trust (Fuzzy- ABR) routing protocol for MANET to improve QoS
and to mitigate network attacks.
Abstract: Cadmium (II) (Cd) is one of the major toxic elemental
pollutants, which is hazardous for humans, animals and plants. γ-
Polyglutamic acid (γ-PGA) is an extracellular biopolymer produced
by several species of Bacillus which has been reported to be an
effective biosorbent for metal ions. The effect of γ-PGA on growth of
rice grown under laboratory conditions was investigated. Rice seeds
were germinated and then grown at 30±1°C on filter paper soaked
with Cd solution and γ-PGA for 7 days. The result showed that Cd
significantly inhibited the growth of roots, shoots by reducing root,
and shoot lengths. Fresh and dry weights also decreased compared
with control; however, the addition of 500 mg·L-1 γ-PGA alleviated
rice seedlings from the adverse effects of Cd. The analysis of
physiological traits revealed that Cd caused a decrease in the total
chlorophyll and soluble protein contents and amylase activities in all
treatments. The Cd content in seedling tissues increased for the Cd
250 μM treatment (P
Abstract: The objective of this study was to evaluate the
effects of calving season on the production and economic efficiency
of dairy farms in Egypt. Our study was performed at dairy
production farms in the Alexandria, Behera, and Kafr El-Sheikh
provinces of Egypt from summer 2010 to winter 2013. The
randomly selected dairy farms had herds consisting of Baladi,
Holstein-Friesian, or cross-bred (Baladi × Holstein-Friesian) cows.
The data were collected from production records and responses to a
structured questionnaire. The average total return differed
significantly (P < 0.05) between the different cattle breeds and
calving seasons. The average total return was highest for the
Holstein- Friesian cows that calved in the winter (29106.42
EGP/cow/year), and it was lowest for Baladi cows that calved in the
summer (12489.79 EGP/cow/year). Differences in total returns
between the cows that calved in the winter or summer or between
the foreign and native breeds, as well as variations in calf prices,
might have contributed to the differences in milk yield. The average
net profit per cow differed significantly (P < 0.05) between the cattle
breeds and calving seasons. The average net profit values for the
Baladi cows that calved in the winter or summer were 2413 and
2994.96 EGP/cow/year, respectively, and those for the Holstein-
Friesian cows were 10744.17 and 7860.56 EGP/cow/year,
respectively, whereas those for the cross-bred cows were 10174.86
and 7571.33 EGP/cow/year, respectively. The variations in net profit
might have resulted from variation in the availability or price of feed
materials, milk prices, or sales volumes. Our results show that the
breed and calving season of dairy cows significantly affected the
economic efficiency of dairy farms in Egypt. The cows that calved
in the winter produced more milk than those that calved in the
summer, which may have been the result of seasonal influences,
such as temperature, humidity, management practices, and the type
of feed or green fodder available.