Abstract: Power Regeneration in Refrigeration Plant concept
has been analyzed and has been shown to be capable of saving about
25% power in Cryogenic Plants with the Power Regeneration System
(PRS) running under nominal conditions. The innovative component
Compressor Expander Group (CEG) based on turbomachinery has
been designed and built modifying CETT compressor and expander,
both selected for optimum plant performance. Experiments have
shown the good response of the turbomachines to run with R404a as
working fluid. Power saving up to 12% under PRS derated conditions
(50% loading) has been demonstrated. Such experiments allowed
predicting a power saving up to 25% under CEG full load.
Abstract: The paper describes the OAS role in dispute
resolution. The authors make an attempt to identify a general pattern
of the OAS activities within the peaceful settlement of interstate
conflicts, in the beginning of 21st century, as well as to analyze some
features of Honduras–Belize, Nicaragua–Honduras, Honduras–El
Salvador, Costa-Rica–Nicaragua, Colombia–Ecuador cases.
Abstract: Now in some countries of the world the cellular
market is on the point of saturation, in others - positive dynamics of
development kept on. The reasons for it are also different, but there
are united by their general susceptibility to innovation changes, if
they are really innovative. If to take as an example the cellular market
of Kazakhstan it is defined by the low percent of smart phones at
consumers, the low population density, undercapacity of the 3G
channel, and absence of universal access to the LTE technology that
limits dynamical growth of this branch. These moments are
aggravated by failures of starting commercial projects by private
companies which prevent to be implemented and widely adopted to a
new product among consumers. The object of the research is possible
integration of wireless and program technologies at which
introduction the idea can regenerate in an innovation. The analysis of
existing projects in the market and the possible union of the
technologies through a prism of theoretical bases of innovative
activity shows that efficiency of the company by development and
introduction of innovations is possible only thanks to strict
observance of all terms and conditions of the innovative process
which main term is profit. Despite that fact that on a global scale the
innovativeness issue of companies is very popular, there are no
researches about possibility of innovative breaks in the field of
wireless access to the Internet in the cellular market of Kazakhstan.
Abstract: The present work describes the implementation of the
Enhanced Collaborative Optimization (ECO) multilevel architecture
with a gradient-based optimization algorithm with the aim of
performing a multidisciplinary design optimization of a generic
unmanned aerial vehicle with morphing technologies. The concepts
of weighting coefficient and dynamic compatibility parameter are
presented for the ECO architecture. A routine that calculates the
aircraft performance for the user defined mission profile and vehicle’s
performance requirements has been implemented using low fidelity
models for the aerodynamics, stability, propulsion, weight, balance
and flight performance. A benchmarking case study for evaluating
the advantage of using a variable span wing within the optimization
methodology developed is presented.
Abstract: This study aimed to identify the alignment of
understanding and assessment practices among secondary school
teachers. The study was carried out using quantitative descriptive
study. The sample consisted of 164 teachers who taught Form 1 and 2
from 11 secondary schools in the district of North Kinta, Perak,
Malaysia. Data were obtained from 164 respondents who answered
Expectation Alignment Understanding and Practices of School
Assessment (PEKDAPS) questionnaire. The data were analysed
using SPSS 17.0+. The Cronbach’s alpha value obtained through
PEKDAPS questionnaire pilot study was 0.86. The results showed
that teachers' performance in PEKDAPS based on the mean value
was less than 3, which means that perfect alignment does not occur
between the understanding and practices of school assessment. Two
major PEKDAPS sub-constructs of articulation across grade and age
and usability of the system were higher than the moderate alignment
of the understanding and practices of school assessment (Min=2.0).
The content focused of PEKDAPs sub-constructs which showed
lower than the moderate alignment of the understanding and practices
of school assessment (Min=2.0). Another two PEKDAPS subconstructs
of transparency and fairness and the pedagogical
implications showed moderate alignment (2.0). The implications of
the study is that teachers need to fully understand the importance of
alignment among components of assessment, learning and teaching
and learning objectives as strategies to achieve quality assessment
process.
Abstract: This paper discusses the design and analysis of a
hybrid PV-Fuel cell energy system destined to power a DC load. The
system is composed of a photovoltaic array, a fuel cell, an
electrolyzer and a hydrogen tank. HOMER software is used in this
study to calculate the optimum capacities of the power system
components that their combination allows an efficient use of solar
resource to cover the hourly load needs. The optimal system sizing
allows establishing the right balance between the daily electrical
energy produced by the power system and the daily electrical energy
consumed by the DC load using a 28 KW PV array, a 7.5 KW fuel
cell, a 40KW electrolyzer and a 270 Kg hydrogen tank. The variation
of powers involved into the DC bus of the hybrid PV-fuel cell system
has been computed and analyzed for each hour over one year: the
output powers of the PV array and the fuel cell, the input power of
the elctrolyzer system and the DC primary load. Equally, the annual
variation of stored hydrogen produced by the electrolyzer has been
assessed. The PV array contributes in the power system with 82%
whereas the fuel cell produces 18%. 38% of the total energy
consumption belongs to the DC primary load while the rest goes to
the electrolyzer.
Abstract: This study introduces two types of self-oscillating
circuits that are frequently found in power electronics applications.
Special effort is made to relate the circuits to the analogous mechanical
systems of some important scientific inventions: Galileo’s pendulum
clock and Coulomb’s friction model. A little touch of related history
and philosophy of science will hopefully encourage curiosity, advance
the understanding of self-oscillating systems and satisfy the aspiration
of some students for scientific literacy. Finally, the two self-oscillating
circuits are applied to design a simple class-D audio amplifier.
Abstract: The dissimilar joint between aluminum/titanium
alloys (Al 6082 and Ti G2) were successfully achieved by CO2 laser
welding with a single pass and without filler material using the
overlap joint design. Laser welding parameters ranges combinations
were experimentally determined using Taguchi approach with the
objective of producing welded joint with acceptable welding profile
and high quality of mechanical properties. In this study a joining of
dissimilar Al 6082 / Ti G2 was resulted in three distinct regions
fusion area in the weldment. These regions are studied in terms of its
microstructural characteristics and microhardness which are directly
affecting the welding quality.
The weld metal was mainly composed of martensite alpha prime.
In two different metals in the two different sides of joint HAZ, grain
growth was detected. The microhardness of the joint distribution also
has shown microhardness increasing in the HAZ of two base metals
and a varying microhardness in fusion zone.
Abstract: Urban Search and Rescue (USAR) is a functional
capability that has been developed to allow the United Kingdom Fire
and Rescue Service to deal with ‘major incidents’ primarily involving
structural collapse. The nature of the work undertaken by USAR
means that staying out of a damaged or collapsed building structure is
not usually an option for search and rescue personnel. As a result
there is always a risk that they themselves could become victims. For
this paper, a systematic and investigative review using desk research
was undertaken to explore the role which structural engineering can
play in assisting search and rescue personnel to conduct structural
assessments when in the field. The focus is on how search and rescue
personnel can assess damaged and collapsed building structures, not
just in terms of structural damage that may been countered, but also
in relation to structural stability. Natural disasters, accidental
emergencies, acts of terrorism and other extreme events can vary
significantly in nature and ferocity, and can cause a wide variety of
damage to building structures. It is not possible or, even realistic, to
provide search and rescue personnel with definitive guidelines and
procedures to assess damaged and collapsed building structures as
there are too many variables to consider. However, understanding
what implications damage may have upon the structural stability of a
building structure will enable search and rescue personnel to better judge
and quantify risk from a life-safety standpoint. It is intended that this
will allow search and rescue personnel to make informed decisions
and ensure every effort is made to mitigate risk, so that they
themselves do not become victims.
Abstract: Over the years, it has been extensively established that
the practice of assuming a structure being fixed at base, leads to gross
errors in evaluation of its overall response due to dynamic loadings
and overestimations in design. The extent of these errors depends on
a number of variables; soil type being one of the major factor. This
paper studies the effect of Soil Structure Interaction (SSI) on multistorey
buildings with varying under-laying soil types after proper
validation of the effect of SSI. Analysis for soft, stiff and very stiff
base soils has been carried out, using a powerful Finite Element
Method (FEM) software package ANSYS v14.5. Results lead to
some very important conclusions regarding time period, deflection
and acceleration responses.
Abstract: Semiconductor crystals smaller than about 10 nm,
known as quantum dots, have properties that differ from large
samples, including a band gap that becomes larger for smaller
particles. These properties create several applications for quantum
dots. In this paper new shapes of quantum dot arrays are used to
enhance the photo physical properties of gold nano-particles. This
paper presents a study of the effect of nano-particles shape, array, and
size on their absorption characteristics.
Abstract: We are facing serious problems related to long-term
depopulation and an aging society with a falling birth rate in Japan. In
this situation, we are suffering from a shortfall in human resources as
well as a shortage of workforce in rural regions. In addition, we are
struggling with a protracted economic slump and excess concentration
of population in the Tokyo Metropolitan area. It is an urgent national
issue to consider how to live in this country and what kind of structure
of society and administration policy is needed. It is necessary to clarify
people’s desire for their way of living and social assistance to be
provided. The aim of this study is to clarify the characteristics of
regional issues and the degree of their seriousness in local
municipalities of Japan. We conducted a questionnaire survey about
regional agenda in all local municipalities in Japan. We obtained
responses concerning the degree of seriousness of regional issues and
degree of importance of policies. Based on the data gathered from the
survey, it is apparent that many local municipalities are facing an
aging population and declining population. We constructed a model to
analyze factors for declining population. Using the model, it was
clarified that a population’s age structure, job opportunities and
income level affect the decline of population. In addition, we showed
the way of the evaluation of state of local municipality.
Abstract: The building sector is responsible, in many
industrialized countries, for about 40% of the total energy
requirements, so it seems necessary to devote some efforts in this
area in order to achieve a significant reduction of energy
consumption and of greenhouse gases emissions.
The paper presents a study aiming at providing a design
methodology able to identify the best configuration of the system
building/plant, from a technical, economic and environmentally point
of view.
Normally, the classical approach involves a building's energy
loads analysis under steady state conditions, and subsequent selection
of measures aimed at improving the energy performance, based on
previous experience made by architects and engineers in the design
team. Instead, the proposed approach uses a sequence of two wellknown
scientifically validated calculation methods (TRNSYS and
RETScreen), that allow quite a detailed feasibility analysis.
To assess the validity of the calculation model, an existing,
historical building in Central Italy, that will be the object of
restoration and preservative redevelopment, was selected as a casestudy.
The building is made of a basement and three floors, with a
total floor area of about 3,000 square meters.
The first step has been the determination of the heating and
cooling energy loads of the building in a dynamic regime by means,
which allows simulating the real energy needs of the building in
function of its use. Traditional methodologies, based as they are on
steady-state conditions, cannot faithfully reproduce the effects of
varying climatic conditions and of inertial properties of the structure.
With this model is possible to obtain quite accurate and reliable
results that allow identifying effective combinations building-HVAC
system.
The second step has consisted of using output data obtained as
input to the calculation model, which enables to compare different
system configurations from the energy, environmental and financial
point of view, with an analysis of investment, and operation and
maintenance costs, so allowing determining the economic benefit of
possible interventions.
The classical methodology often leads to the choice of
conventional plant systems, while our calculation model provides a
financial-economic assessment for innovative energy systems and
low environmental impact.
Computational analysis can help in the design phase, particularly
in the case of complex structures with centralized plant systems, by
comparing the data returned by the calculation model for different
design options.
Abstract: Comparing other methods of waste water treatment,
constructed wetlands are one of the most fascinating practices
because being a natural process they are eco-friendly have low
construction and maintenance cost and have considerable capability
of wastewater treatment. The current research was focused mainly on
comparison of Ranunculus muricatus and Typha latifolia as wetland
plants for domestic wastewater treatment by designing and
constructing efficient pilot scale horizontal subsurface flow
mesocosms. Parameters like chemical oxygen demand, biological
oxygen demand, phosphates, sulphates, nitrites, nitrates, and
pathogenic indicator microbes were studied continuously with
successive treatments. Treatment efficiency of the system increases
with passage of time and with increase in temperature. Efficiency of
T. latifolia planted setups in open environment was fairly good for
parameters like COD and BOD5 which was showing reduction up to
82.5% for COD and 82.6% for BOD5 while DO was increased up to
125%. Efficiency of R. muricatus vegetated setup was also good but
lowers than that of T. latifolia planted showing 80.95% removal of
COD and BOD5. Ranunculus muricatus was found effective in
reducing bacterial count in wastewater. Both macrophytes were
found promising in wastewater treatment.
Abstract: Cemented carbide balls are usually implemented in
industry under the environment of high speed, high temperature,
corrosiveness and strong collisions. However, its application is limited
due to high fabrication cost, processing efficiency and quality. A novel
eccentric lapping method with two rotatable lapping plates was
proposed in this paper. A mathematical model was constructed to
analyze the influence of each design parameter on this lapping method.
To validate this new lapping method, an orthogonal experiment was
conducted with cemented carbide balls (YG6). The simulation model
was verified and the optimal lapping parameters were derived. The
results show that the surface roundness of the balls reaches to 0.65um
from 2um in 1 hour using this lapping method. So, using this novel
lapping method, it can effectively improve the machining precision
and efficiency of cemented carbide balls.
Abstract: Knowledge is considered as an important asset which
can help organizations to create competitive advantage. The necessity
of taking care of these assets is more important in these days – in
days of turbulent changes in business environment. Knowledge could
facilitate adaption to constant changes. The aim of this paper is to
describe how the knowledge sharing can be supported in the
manufacturing companies. The methods of case studies and grounded
theory were used to present information gained by carrying out semistructured
interviews. Results show that knowledge sharing is
supported in very similar ways in respondent companies.
Abstract: This paper shows an experimental testing of a small
unit for combustion of solid fuels, such as charcoal and wood logs,
that can provide electricity. One of the concepts is that the unit does
not require qualified personnel for its operation. The unit itself is
composed of two main parts. The design requires a heat producing
stove and electricity producing thermoelectric generator. After the
construction the unit was tested and the results show that the
emission release is within the legislative requirements for emission
production and environmental protection. That qualifies such unit for
indoor application.
Abstract: Nowadays, huge amount of multimedia repositories
make the browsing, retrieval and delivery of video contents very slow
and even difficult tasks. Video summarization has been proposed to
improve faster browsing of large video collections and more efficient
content indexing and access. In this paper, we focus on approaches to
video summarization. The video summaries can be generated in many
different forms. However, two fundamentals ways to generate
summaries are static and dynamic. We present different techniques
for each mode in the literature and describe some features used for
generating video summaries. We conclude with perspective for
further research.
Abstract: This article focuses on the issue of airport emergency
plans, which are documents describing reactions to events with
impact on aviation safety or aviation security. The article specifically
focuses on the use and creation of emergency plans, where could be
found a number of disagreements between different stakeholders, for
which the airport emergency plan applies. Those are the friction
surfaces of interfaces, which is necessary to identify and ensure them
smooth process to avoid dangerous situations or delay.
Abstract: Contemporary city is a subject to rapid economic and
social changes. Therefore, it requires an active policy designed to
meet the diverse needs of their residents, build competitive position
and capacity to compete with other cities. Competitiveness of cities
depends largely on their resources but also to a large extent, on the
policies and performance of local authorities. Cooperation with social
sector also plays an important role, as it affects the use of resources
and builds an advantage over other cities.
The subject of this article is city's contemporary problems of
development with particular emphasis on central areas. This issue is a
starting point for reflection on the process of urban regeneration in
medium size cities in Poland, as well as cooperation between various
actors and their roles in the revitalization processes of Polish cities'
centers.