Abstract: In this paper the effect of wall waviness of side walls
in a two-dimensional wavy enclosure is numerically investigated.
Two vertical wavy walls and straight top wall are kept isothermal and
the bottom wall temperature is higher and spatially varying with
cosinusoidal temperature distribution. A computational code based on
Finite-volume approach is used to solve governing equations and
SIMPLE method is used for pressure velocity coupling. Test is
performed for several different numbers of undulations. The Prandtl
number was kept constant and the Ra number denotes that the flow is
laminar. Temperature and velocity fields are determined. Therefore,
according to the obtained results a correlation is proposed for average
Nusselt number as a function of number of side wall waves. The
results indicate that the Nusselt number is highly affected by number
of waves and increasing it decreases the wavy walls Nusselt number;
although the Nusselt number is not highly affected by surface
waviness when the number of undulations is below one.
Abstract: The article discusses multimodal mobility in
contemporary societies as a main planning and organization issue in
the functioning of administrative bodies, a problem which really
exists in the space of contemporary cities in terms of shaping modern
transport systems. The article presents classification of available
resources and initiatives undertaken for developing multimodal
mobility. Solutions can be divided into three groups of measures –
physical measures in the form of changes of the transport network
infrastructure, organizational ones (including transport policy) and
information measures. The latter ones include in particular direct
support for people travelling in the transport network by providing
information about ways of using available means of transport. A
special measure contributing to this end is a trip planner. The article
compares several selected planners. It includes a short description of
the Green Travelling Project, which aims at developing a planner
supporting environmentally friendly solutions in terms of transport
network operation. The article summarizes preliminary findings of
the project.
Abstract: Urban greenery remains the bastion of urban
landscape and a key to sustainable development due to its integral
connections to the general health and wellbeing of urban residents.
However, in an era of rapid urbanisation, recent studies indicate that
urban greenery, especially ecologically sensitive areas, in many
African cities is becoming increasingly depleted. Given the scale and
rate of natural and anthropogenic change, effective management of
urban greenery as the ultimate goal of restoring depleting urban
landscapes is urgent. This review advocates for an urban resilience
model to managing urban greenery.
Abstract: The use of IT equipment has become a part of every
day. However, each device that is part of cyberspace should be
secured against unauthorized use. It is very important to know the
basics of these security devices, but also the basics of safe conduct
their owners. This information should be part of every curriculum
computer science education in primary and secondary schools.
Therefore, the work focuses on the education of pupils in primary and
secondary schools on the Internet. Analysis of the current state
describes approaches to the education of pupils in security issues on
the Internet. The paper presents a questionnaire-based survey which
was carried out in the Czech Republic, whose task was to ascertain
the level of opinion pupils in primary and secondary schools on the
issue of communication in social networks. The research showed that
awareness of socio-pathological phenomena on the Internet
environment is very low. Based on the results it was proposed
appropriate ways of teaching to this issue and its inclusion a proposal
of curriculum for primary and secondary schools.
Abstract: This paper is concerning the issues of behaviour of
lightweight expanded clay aggregates concrete exposed to high
temperature. Lightweight aggregates from expanded clay are
produced by firing of row material up to temperature 1050°C.
Lightweight aggregates have suitable properties in terms of volume
stability, when exposed to temperatures up to 1050°C, which could
indicate their suitability for construction applications with higher risk
of fire. The test samples were exposed to heat by using the standard
temperature-time curve ISO 834. Negative changes in resulting
mechanical properties, such as compressive strength, tensile strength,
and flexural strength were evaluated. Also visual evaluation of the
specimen was performed. On specimen exposed to excessive heat, an
explosive spalling could be observed, due to evaporation of
considerable amount of unbounded water from the inner structure of
the concrete.
Abstract: In this paper, we present a comparative assessment of
Space Vector Pulse Width Modulation (SVPWM) and Model
Predictive Control (MPC) for two-level three phase (2L-3P) Voltage
Source Inverter (VSI). VSI with associated system is subjected to
both control techniques and the results are compared.
Matlab/Simulink was used to model, simulate and validate the
control schemes. Findings of this study show that MPC is superior to
SVPWM in terms of total harmonic distortion (THD) and
implementation.
Abstract: A wireless sensor network (WSN) is a collection of
sensor nodes organized into a cooperative network. These nodes
communicate through a wireless antenna. Reduction in physical size
and multiband operation is an important requirement of WSN
antenna. Fractal antenna is used for miniaturization and multiband
operation. The self-similar or self-affine and space filling property of
fractal geometry increases the effective electrical length of the
antenna, reduces the size and make them frequency independent. This
paper elaborates on Dual band fractal antenna with Coplanar
Waveguide (CPW) feed for WSN. The proposed antenna is designed
on a FR4 substrate with the dimension of 27mm x 28.5mm x 1.6mm,
resonates at 2.4GHz and 5.2GHz with a return loss less than -10dB.
The design and simulation process is carried out using IE3D
simulation software. The simulated and measured results are found in
good agreement.
Abstract: The effect of trucks on the level of service is
determined by considering passenger car equivalents (PCE) of trucks.
The current version of Highway Capacity Manual (HCM) uses a
single PCE value for all tucks combined. However, the composition
of truck traffic varies from location to location; therefore, a single
PCE value for all trucks may not correctly represent the impact of
truck traffic at specific locations. Consequently, present study
developed separate PCE values for single-unit and combination
trucks to replace the single value provided in the HCM on different
freeways. Site specific PCE values, were developed using concept of
spatial lagging headways (that is the distance between rear bumpers
of two vehicles in a traffic stream) measured from field traffic data.
The study used data from four locations on a single urban freeway
and three different rural freeways in Indiana. Three-stage-leastsquares
(3SLS) regression techniques were used to generate models
that predicted lagging headways for passenger cars, single unit trucks
(SUT), and combination trucks (CT). The estimated PCE values for
single-unit and combination truck for basic urban freeways (level
terrain) were: 1.35 and 1.60, respectively. For rural freeways the
estimated PCE values for single-unit and combination truck were:
1.30 and 1.45, respectively. As expected, traffic variables such as
vehicle flow rates and speed have significant impacts on vehicle
headways. Study results revealed that the use of separate PCE values
for different truck classes can have significant influence on the LOS
estimation.
Abstract: As the human race will continue to explore the space
by creating new space transportation means and sending them to other
planets, the enhance of atmospheric reentry study is crucial. In this
context, an analysis of mass recession rate of ablative materials for
thermal shields of reentry spacecrafts is important to be carried out.
The paper describes a new estimation method for calculating the mass
recession of an ablator system made of carbon fiber reinforced plastic
materials. This method is based on Arrhenius equation for low
temperatures and, for high temperatures, on a theory applied for the
recession phenomenon of carbon fiber reinforced plastic materials,
theory which takes into account the presence of the resin inside the
materials. The space mission of USERS spacecraft is considered as a
case study.
Abstract: Persea declinata (Bl.) Kosterm is a member of the
Lauraceae family, widely distributed in Southeast Asia. It is from the
same genus with avocado (Persea americana Mill), which is widely
consumed as food and for medicinal purposes. In the present study,
we examined the anticancer properties of Persea declinata (Bl.)
Kosterm bark methanolic crude extract (PDM). PDM exhibited a
potent antiproliferative effect in MCF-7 human breast cancer cells,
with an IC50 value of 16.68 .g/mL after 48h of treatment. We
observed that PDM caused cell cycle arrest and subsequent apoptosis
in MCF-7 cells, as exhibited by increased population at G0/G1 phase,
higher lactate dehydrogenase (LDH) release, and DNA
fragmentation. Mechanistic studies showed that PDM caused
significant elevation in ROS production, leading to perturbation of
mitochondrial membrane potential, cell permeability, and activation
of caspases-3/7. On the other hand, real-time PCR and Western blot
analysis showed that PDM treatment increased the expression of the
proapoptotic molecule, Bax, but decreased the expression of
prosurvival proteins, Bcl-2 and Bcl-xL, in a dose-dependent manner.
These findings imply that PDM could inhibit proliferation in MCF-7
cells via cell cycle arrest and apoptosis induction, indicating its
potential as a therapeutic agent worthy of further development.
Abstract: Load Forecasting plays a key role in making today's
and future's Smart Energy Grids sustainable and reliable. Accurate
power consumption prediction allows utilities to organize in advance
their resources or to execute Demand Response strategies more
effectively, which enables several features such as higher
sustainability, better quality of service, and affordable electricity
tariffs. It is easy yet effective to apply Load Forecasting at larger
geographic scale, i.e. Smart Micro Grids, wherein the lower available
grid flexibility makes accurate prediction more critical in Demand
Response applications. This paper analyses the application of
short-term load forecasting in a concrete scenario, proposed within the
EU-funded GreenCom project, which collect load data from single
loads and households belonging to a Smart Micro Grid. Three
short-term load forecasting techniques, i.e. linear regression, artificial
neural networks, and radial basis function network, are considered,
compared, and evaluated through absolute forecast errors and training
time. The influence of weather conditions in Load Forecasting is also
evaluated. A new definition of Gain is introduced in this paper, which
innovatively serves as an indicator of short-term prediction
capabilities of time spam consistency. Two models, 24- and
1-hour-ahead forecasting, are built to comprehensively compare these
three techniques.
Abstract: The success of any retail business is predisposed by its
swift response and its knack in understanding the constraints and the
requirements of customers. In this paper a conceptual design model
of an automated customer-friendly supermarket has been proposed.
In this model a 10-sided, space benefited, regular polygon shaped
gravity shelves have been designed for goods storage and effective
customer-specific algorithms have been built-in for quick automatic
delivery of the randomly listed goods. The algorithm is developed
with two main objectives, viz., delivery time and priority. For
meeting these objectives the randomly listed items are reorganized
according to the critical-path of the robotic arm specific to the
identified shop and its layout and the items are categorized according
to the demand, shape, size, similarity and nature of the product for an
efficient pick-up, packing and delivery process. We conjectured that
the proposed automated supermarket model reduces business
operating costs with much customer satisfaction warranting a winwin
situation.
Abstract: For a given a simple connected graph, we present
some new bounds via a new approach for a special topological index
given by the sum of the real number power of the non-zero
normalized Laplacian eigenvalues. To use this approach presents an
advantage not only to derive old and new bounds on this topic but
also gives an idea how some previous results in similar area can be
developed.
Abstract: An anthropometric study applied to 1,115 students of
the Faculty of Chemical Sciences and Engineering of the
Autonomous University of California. Thirteen individual
measurements were taken in a sitting position. The results obtained
allow forming a reliable anthropometric database for statistical
studies and analysis and inferences of specific distributions, so the
opinion of experts in occupational medicine recommendations may
emit to reduce risks resulting in an alteration of the vital signs during
the execution of their school activities. Another use of these analyses
is to use them as a reliable reference for future deeper research, to the
design of spaces, tools, utensils, workstations, with anthropometric
dimensions and ergonomic characteristics suitable to use.
Abstract: This paper presents an anthropometric study
conducted to 300 employees in a maquiladora industry that belongs
to the cluster of medical products as part of a research project to
pretend simulate workplace conditions under which operators
conduct their activities. This project is relevant because traditionally
performed a study to design ergonomic workspaces according to
anthropometric profile of users, however, this paper demonstrates the
importance of making decisions when the infrastructure cannot be
adapted for economic whichever put emphasis on user activity.
Abstract: Economic Dispatch (ED) is one of the most
challenging problems of power system since it is difficult to determine
the optimum generation scheduling to meet the particular load demand
with the minimum fuel costs while all constraints are satisfied. The
objective of the Economic Dispatch Problems (EDPs) 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. In this paper, an efficient and practical steady-state genetic
algorithm (SSGAs) has been proposed for solving the economic
dispatch problem. The objective is to minimize the total generation
fuel cost and keep the power flows within the security limits. To
achieve that, the present work is developed to determine the optimal
location and size of capacitors in transmission power system where,
the Participation Factor Algorithm and the Steady State Genetic
Algorithm are proposed to select the best locations for the capacitors
and determine the optimal size for them.
Abstract: The main objective of this study was to identify
factors and conditions that motivated and encouraged students
towards the math class and the factors that made this class an
attractive and lovely one. To do this end, questionnaires consisting of
15 questions were distributed among 85 math teachers working in
schools of Zahedan. Having collected and reviewed these
questionnaires, it was shown that doing activity in math class
(activity of students while teaching) and previous math teachers'
behaviors have had much impact on encouraging the students
towards mathematics. Separation of educational classroom of
mathematics from the main classroom (which is decorated with crafts
created by students themselves with regard to math book including
article, wall newspaper, figures and formulas), peers, size and
appearance of math book, first grade teachers in each educational
level, among whom the Elementary first grade teachers had more
importance and impact, were among the most influential and
important factors in this regard. Then, school environment, family,
conducting research related to mathematics, its application in daily
life and other courses and studying the history of mathematics were
categorized as important factors that would increase the students’
interest in mathematics.
Abstract: The aim of this work is to present a theoretical analysis of a 2D ultrasound transducer comprised of crossed arrays of metal strips placed on both sides of thin piezoelectric layer (a). Such a structure is capable of electronic beam-steering of generated wavebeam both in elevation and azimuth. In this paper a semi-analytical model of the considered transducer is developed. It is based on generalization of the well-known BIS-expansion method. Specifically, applying the electrostatic approximation, the electric field components on the surface of the layer are expanded into fast converging series of double periodic spatial harmonics with corresponding amplitudes represented by the properly chosen Legendre polynomials. The problem is reduced to numerical solving of certain system of linear equations for unknown expansion coefficients.
Abstract: Kinematic data wisely correlate vector quantities in
space to scalar parameters in time to assess the degree of symmetry
between the intact limb and the amputated limb with respect to a
normal model derived from the gait of control group participants.
Furthermore, these particular data allow a doctor to preliminarily
evaluate the usefulness of a certain rehabilitation therapy.
Kinetic curves allow the analysis of ground reaction forces (GRFs)
to assess the appropriateness of human motion.
Electromyography (EMG) allows the analysis of the fundamental
lower limb force contributions to quantify the level of gait
asymmetry. However, the use of this technological tool is expensive
and requires patient’s hospitalization. This research work suggests
overcoming the above limitations by applying artificial neural
networks.
Abstract: Pomegranate (Punica granatum L.) is an ancient fruit of great medical interest and rich source of antioxidants. Pesticides as dimethoate play a crucial role in the occurrence many diseases in plants, animal and human. Therefore the ability of Pomegranate (Punica granatum L.) to alleviate hepatotoxicity induced by organophosphate pesticide dimethoate was investigated. Albino male rats were divided randomly into 4 groups and kept at 7 animals per group in an environmentally controlled condition for 6 weeks. The first group was served as a control group (basal diet), the second group fed on basal diet supplemented with 5% freeze dried pomegranate seeds, the third group fed on 20 ppm dimethoate contaminated diet and the last group fed on dimethoate contaminated diet supplemented with 5% freeze dried pomegranate seeds. The results revealed that administration of dimethoate caused high significant increased in liver functions: alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) activities as well as lipid peroxide (malonaldhyde, MDA); on the other hand high significant decreased on glutathione (GSH), glutathione peroxidase (GPx), albumin and total protein were observed. However addition of 5% freeze dried pomegranate seeds significantly improved all previously mentioned parameters. These results indicate the dimethoate induced hepatotoxicity and highlight the protective effect of pomegranate seeds as a potential protective agent against dimethoate induced hepatotoxicity. This may be attributed to the powerful antioxidants (polyphenols, total phenols, and total flavonoids) which present in high levels in pomegranate as well as improving the immunity by activation of antioxidant enzymes GSH and GPx.