Abstract: The study explores the hybrid combination of Hydrodynamic Cavitation (HC) and Subcritical Wet Air Oxidation-based pretreatment of complex industrial effluent to enhance the biodegradability selectively (without major COD destruction) to facilitate subsequent enhanced downstream processing via anaerobic or aerobic biological treatment. Advanced oxidation based techniques can be less efficient as standalone options and a hybrid approach by combining Hydrodynamic Cavitation (HC), and Wet Air Oxidation (WAO) can lead to a synergistic effect since both the options are based on common free radical mechanism. The HC can be used for initial turbulence and generation of hotspots which can begin the free radical attack and this agitating mixture then can be subjected to less intense WAO since initial heat (to raise the activation energy) can be taken care by HC alone. Lab-scale venturi-based hydrodynamic cavitation and wet air oxidation reactor with biomethanated distillery wastewater (BMDWW) as a model effluent was examined for establishing the proof-of-concept. The results indicated that for a desirable biodegradability index (BOD: COD - BI) enhancement (up to 0.4), the Cavitation (standalone) pretreatment condition was: 5 bar and 88 min reaction time with a COD reduction of 36 % and BI enhancement of up to 0.27 (initial BI - 0.17). The optimum WAO condition (standalone) was: 150oC, 6 bar and 30 minutes with 31% COD reduction and 0.33 BI. The hybrid pretreatment (combined Cavitation + WAO) worked out to be 23.18 min HC (at 5 bar) followed by 30 min WAO at 150oC, 6 bar, at which around 50% COD was retained yielding a BI of 0.55. FTIR & NMR analysis of pretreated effluent indicated dissociation and/or reorientation of complex organic compounds in untreated effluent to simpler organic compounds post-pretreatment.
Abstract: Quad Flat No-Lead (QFN) packages have become very popular for turners, converters and audio amplifiers, among others applications, needing efficient power dissipation in small footprints. Since semiconductor junction temperature (TJ) is a critical parameter in the product quality. And to ensure that die temperature does not exceed the maximum allowable TJ, a thermal analysis conducted in an earlier development phase is essential to avoid repeated re-designs process with huge losses in cost and time. A simulation tool capable to estimate die temperature of components with QFN package was developed. Allow establish a non-empirical way to define an acceptance criterion for amount of voids in solder interface between its exposed pad and Printed Circuit Board (PCB) to be applied during industrialization process, and evaluate the impact of PCB designs parameters. Targeting PCB layout designer as an end user for the application, a user-friendly interface (GUI) was implemented allowing user to introduce design parameters in a convenient and secure way and hiding all the complexity of finite element simulation process. This cost effective tool turns transparent a simulating process and provides useful outputs after acceptable time, which can be adopted by PCB designers, preventing potential risks during the design stage and make product economically efficient by not oversizing it. This article gathers relevant information related to the design and implementation of the developed tool, presenting a parametric study conducted with it. The simulation tool was experimentally validated using a Thermal-Test-Chip (TTC) in a QFN open-cavity, in order to measure junction temperature (TJ) directly on the die under controlled and knowing conditions. Providing a short overview about standard thermal solutions and impacts in exposed pad packages (i.e. QFN), accurately describe the methods and techniques that the system designer should use to achieve optimum thermal performance, and demonstrate the effect of system-level constraints on the thermal performance of the design.
Abstract: Younger and younger children are now using a smartphone, a device which has become ‘a must have’ and the life of children would be almost ‘unthinkable’ without one. Devices are becoming lighter and lighter but offering an array of options and applications as well as the unavoidable access to the Internet, without which it would be almost unusable. Numerous features such as taking of photographs, listening to music, information search on the Internet, access to social networks, usage of some of the chatting and messaging services, are only some of the numerous features offered by ‘smart’ devices. They have replaced the alarm clock, home phone, camera, tablet and other devices. Their use and possession have become a part of the everyday image of young people. Apart from the positive aspects, the use of smartphones has also some downsides. For instance, free time was usually spent in nature, playing, doing sports or other activities enabling children an adequate psychophysiological growth and development. The greater usage of smartphones during classes to check statuses on social networks, message your friends, play online games, are just some of the possible negative aspects of their application. Considering that the age of the population using smartphones is decreasing and that smartphones are no longer ‘foreign’ to children of pre-school age (smartphones are used at home or in coffee shops or shopping centers while waiting for their parents, playing video games often inappropriate to their age), particular attention must be paid to a very sensitive group, the teenagers who almost never separate from their ‘pets’. This paper is divided into two sections, theoretical and empirical ones. The theoretical section gives an overview of the pros and cons of the usage of smartphones, while the empirical section presents the results of a research conducted in three elementary schools regarding the usage of smartphones and, specifically, their usage during classes, during breaks and to search information on the Internet, check status updates and 'likes’ on the Facebook social network.
Abstract: Effective treatment of ground instability is essential when managing the impacts associated with historic mining. A field trial was undertaken by the Coal Authority to investigate the geotechnical performance and potential use of composite materials comprising resin and fill or stone to safely treat surface collapses, such as crown-holes, associated with shallow mining. Test pits were loosely filled with various granular fill materials. The fill material was injected with commercially available silicate and polyurethane resin foam products. In situ and laboratory testing was undertaken to assess the geotechnical properties of the resultant composite materials. The test pits were subsequently excavated to assess resin permeation. Drilling and resin injection was easiest through clean limestone fill materials. Recycled building waste fill material proved difficult to inject with resin; this material is thus considered unsuitable for use in resin composites. Incomplete resin permeation in several of the test pits created irregular ‘blocks’ of composite. Injected resin foams significantly improve the stiffness and resistance (strength) of the un-compacted fill material. The stiffness of the treated fill material appears to be a function of the stone particle size, its associated compaction characteristics (under loose tipping) and the proportion of resin foam matrix. The type of fill material is more critical than the type of resin to the geotechnical properties of the composite materials. Resin composites can effectively support typical design imposed loads. Compared to other traditional treatment options, such as cement grouting, the use of resin composites is potentially less disruptive, particularly for sites with limited access, and thus likely to achieve significant reinstatement cost savings. The use of resin composites is considered a suitable option for the future treatment of shallow mining collapses.
Abstract: The present study explains the somatic marker theory of Antonio Damasio, which indicates that when making a decision, the stored or possible future scenarios (future memory) images allow people to feel for a moment what would happen when they make a choice, and how this is emotionally marked. This process can be conscious or unconscious. The development of new Neuromarketing techniques such as functional magnetic resonance imaging (fMRI), carries a greater understanding of how the brain functions and consumer behavior. In the results observed in different studies using fMRI, the evidence suggests that the somatic marker and future memories influence the decision-making process, adding a positive or negative emotional component to the options. This would mean that all decisions would involve a present emotional component, with a rational cost-benefit analysis that can be performed later.
Abstract: The cumulative costs for O&M may represent as
much as 65%-90% of the turbine's investment cost. Nowadays the
cost effectiveness concept becomes a decision-making and
technology evaluation metric. The cost of energy metric accounts for
the effect replacement cost and unscheduled maintenance cost
parameters. One key of the proposed approach is the idea of
maintaining the WTs which can be captured via use of a finite state
Markov chain. Such a model can be embedded within a probabilistic
operation and maintenance simulation reflecting the action to be
done. In this paper, an approach of estimating the cost of O&M is
presented. The finite state Markov model is used for decision
problems with number of determined periods (life cycle) to predict
the cost according to various options of maintenance.
Abstract: The question of legal liability over injury arising out
of the import and the introduction of GM food emerges as a crucial
issue confronting to promote GM food and its derivatives. There is a
greater possibility of commercialized GM food from the exporting
country to enter importing country where status of approval shall not
be same. This necessitates the importance of fixing a liability
mechanism to discuss the damage, if any, occurs at the level of
transboundary movement or at the market. There was a widespread consensus to develop the Cartagena
Protocol on Biosafety and to give for a dedicated regime on liability
and redress in the form of Nagoya Kuala Lumpur Supplementary
Protocol on the Liability and Redress (‘N-KL Protocol’) at the
international context. The national legal frameworks based on this
protocol are not adequately established in the prevailing food
legislations of the developing countries. The developing economy
like India is willing to import GM food and its derivatives after the
successful commercialization of Bt Cotton in 2002. As a party to the
N-KL Protocol, it is indispensable for India to formulate a legal
framework and to discuss safety, liability, and regulatory issues
surrounding GM foods in conformity to the provisions of the
Protocol. The liability mechanism is also important in the case where
the risk assessment and risk management is still in implementing
stage. Moreover, the country is facing GM infiltration issues with its
neighbors Bangladesh. As a precautionary approach, there is a need
to formulate rules and procedure of legal liability to discuss any kind
of damage occurs at transboundary trade. In this context, the
proposed work will attempt to analyze the liability regime in the
existing Food Safety and Standards Act, 2006 from the applicability
and domestic compliance and to suggest legal and policy options for
regulatory authorities.
Abstract: Project Portfolio Management (PPM) is an essential
component of an organisation’s strategic procedures, which requires
attention of several factors to envisage a range of long-term outcomes
to support strategic project portfolio decisions. To evaluate overall
efficiency at the portfolio level, it is essential to identify the
functionality of specific projects as well as to aggregate those
findings in a mathematically meaningful manner that indicates the
strategic significance of the associated projects at a number of levels
of abstraction. PPM success is directly associated with the quality of
decisions made and poor judgment increases portfolio costs. Hence,
various Multi-Criteria Decision Making (MCDM) techniques have
been designed and employed to support the decision-making
functions. This paper reviews possible options to enhance the
decision-making outcomes in organisational portfolio management
processes using the Analytic Hierarchy Process (AHP) both from
academic and practical perspectives and will examine the usability,
certainty and quality of the technique. The results of the study will
also provide insight into the technical risk associated with current
decision-making model to underpin initiative tracking and strategic
portfolio management.
Abstract: Machine visualization is an area of interest with fast
and progressive development. We present a method of machine
visualization which will be applicable in real industrial conditions
according to current needs and demands. Real factory data were
obtained in a newly built research plant. Methods described in this
paper were validated on a case study. Input data were processed and
the virtual environment was created. The environment contains
information about dimensions, structure, disposition, and function.
Hardware was enhanced by modular machines, prototypes, and
accessories. We added functionalities and machines into the virtual
environment. The user is able to interact with objects such as testing
and cutting machines, he/she can operate and move them. Proposed
design consists of an environment with two degrees of freedom of
movement. Users are in touch with items in the virtual world which
are embedded into the real surroundings. This paper describes development of the virtual environment. We
compared and tested various options of factory layout virtualization
and visualization. We analyzed possibilities of using a 3D scanner in
the layout obtaining process and we also analyzed various virtual
reality hardware visualization methods such as: Stereoscopic (CAVE)
projection, Head Mounted Display (HMD) and augmented reality
(AR) projection provided by see-through glasses.
Abstract: Reduction of energy consumption in built
infrastructure, through the installation of energy-efficient
technologies, is a major approach to achieving sustainability. In
practice, the viability of energy efficiency projects strongly depends
on the cost reimbursement and profitability. These projects are
subject to failure if the actual cost savings do not reimburse the
project cost promptly. In such cases, refinancing could be a solution
to benefit from the long-term returns of the project, if implemented
wisely. However, very little is still known about the effect of
refinancing options on financial performance of energy efficiency
projects. In order to fill this gap, the present study investigates the
financial behavior of energy efficiency projects with focus on
refinancing options, such as Leveraged Loans. A System Dynamics
(SD) model is introduced, and the model application is presented
using an actual case-study data. The case study results indicate that
while high-interest start-ups make using Leveraged Loan inevitable,
refinancing can rescue the project and bring about profitability. This
paper also presents some managerial implications of refinancing
energy efficiency projects based on the case-study analysis. Results
of this study help to implement financially viable energy efficiency
projects so that the community could benefit from their
environmental advantages widely.
Abstract: Hydraulic fracturing is one of the most important
stimulation techniques available to the petroleum engineer to extract
hydrocarbons in tight gas sandstones. It allows more oil and gas
production in tight reservoirs as compared to conventional means.
The main aim of the study is to optimize the hydraulic fracturing as
technique and for this purpose three multi-zones layer formation is
considered and fractured contemporaneously. The three zones are
named as Zone1 (upper zone), Zone2 (middle zone) and Zone3
(lower zone) respectively and they all occur in shale rock. Simulation was performed with Mfrac integrated software which
gives a variety of 3D fracture options. This simulation process
yielded an average fracture efficiency of 93.8%for the three
respective zones and an increase of the average permeability of the
rock system. An average fracture length of 909 ft with net height
(propped height) of 210 ft (average) was achieved. Optimum
fracturing results was also achieved with maximum fracture width of
0.379 inches at an injection rate of 13.01 bpm with 17995 Mscf of
gas production.
Abstract: With the increasing population and intensive land use,
huge traffic demand is generating worldwide both in developing and
developed countries. As a developing country, Bangladesh is also
facing the same problem in recent years by producing huge numbers
of daily trips. As a matter of fact, extensive traffic demand is
increasing day by day. Also, transport system in Dhaka is
heterogeneous, reflecting the heterogeneity in the socio-economic
and land use patterns. Trips produced here are for different purposes
such as work, business, educational etc. Due to the significant
concentration of educational institutions a large share of the trips are
generated by educational purpose. And one of the major percentages
of educational trips is produced by university going students and
most of them are travelled by car, bus, train, taxi, rickshaw etc. The
aim of the study was to find out the university students’ perception on
public transit ridership. A survey was conducted among 330 students
from eight different universities. It was found out that 26% of the
trips produced by university going students are travelled by public
bus service and only 5% are by train. Percentage of car share is 16%
and 12% of the trips are travelled by private taxi. It has been
observed from the study, students those who prefer bus instead of
other options, 42 percent of their family resides outside Dhaka. And
those who prefer walking, of them, over 40 percent students’ family
reside outside of Dhaka and of them over 85 percent students have a
tendency to live in a mess. On the contrary, students travelling by car
represents, most of their family reside in Dhaka. The study also
revealed that the most important reason that restricts students not to
use public transit is poor service. Negative attitudes such as
discomfort, uneasiness in using public transit also reduces the usage
of public transit. The poor waiting area is another major cause of not
using public transit. Insufficient security also plays a significant role
in not using public transit. On the contrary, the fare is not a problem
for students those who use public transit as a mode of transportation.
Students also think stations are not far away from their home or
institution and they do not need to wait long for the buses or trains. It
was also found accessibility to public transit is moderate.
Abstract: Different countries have introduced different schemes
and policies to counter global warming. The rationale behind the
proposed policies and the potential barriers to successful
implementation of the policies adopted by the countries were
analyzed and estimated based on different models. It is argued that
these models enhance the transparency and provide a better
understanding to the policy makers. However, these models are
underpinned with several structural and baseline assumptions. These
assumptions, modeling features and future prediction of emission
reductions and other implication such as cost and benefits of a
transition to a low-carbon economy and its economy wide impacts
were discussed. On the other hand, there are potential barriers in the
form political, financial, and cultural and many others that pose a
threat to the mitigation options.
Abstract: Currently, planners try to have more green travel
options to decrease economic, social and environmental problems.
Therefore, this study tries to find significant urban travel factors to be
used to increase the usage of alternative urban travel modes. This
paper attempts to identify the relationship between prominent urban
mobility indicators and daily trips by public transport in 30 cities
from various parts of the world. Different travel modes,
infrastructures and cost indicators were evaluated in this research as
mobility indicators. The results of multi-linear regression analysis
indicate that there is a significant relationship between mobility
indicators and the daily usage of public transport.
Abstract: The recent interest in alternative and renewable
energy systems results in increased installed capacity ratio of such
systems in total energy production of the world. Specifically, Wind
Energy Conversion Systems (WECS) draw significant attention
among possible alternative energy options, recently. On the contrary
of the positive points of penetrating WECS in all over the world in
terms of environment protection, energy independence of the
countries, etc., there are significant problems to be solved for the grid
connection of large scale WECS. The reactive power regulation,
voltage variation suppression, etc. can be presented as major issues to
be considered in this regard. Thus, this paper evaluates the
application of a Static VAr Compensator (SVC) unit for the reactive
power regulation and operation continuity of WECS during a fault
condition. The system is modeled employing the IEEE 13 node test
system. Thus, it is possible to evaluate the system performance with
an overall grid simulation model close to real grid systems. The
overall simulation model is developed in
MATLAB/Simulink/SimPowerSystems® environments and the
obtained results effectively match the target of the provided study.
Abstract: The goal of this experiment is to evaluate the
effectiveness of different leachate pre-treatment options in terms of
COD and ammonia removal. This research focused on the evaluation
of physical-chemical methods for pre-treatment of leachate that
would be effective and rapid in order to satisfy the requirements of
the sewer discharge by-laws. The four pre-treatment options
evaluated were: air stripping, chemical coagulation, electrocoagulation
and advanced oxidation with sodium ferrate. Chemical
coagulation reported the best COD removal rate at 43%, compared to
18% for both air stripping and electro-coagulation, and 20% for
oxidation with sodium ferrate. On the other hand, air stripping was
far superior to the other treatment options in terms of ammonia
removal with 86%. Oxidation with sodium ferrate reached only 16%,
while chemical coagulation and electro-coagulation removed less
than 10%. When combined, air stripping and chemical coagulation
removed up to 50% COD and 85% ammonia.
Abstract: Numerical studies have been carried out using a
validated two-dimensional standard k-omega turbulence model for
the design optimization of a thrust vector control system using shock
induced self-impinging supersonic secondary double jet. Parametric
analytical studies have been carried out at different secondary
injection locations to identifying the highest unsymmetrical
distribution of the main gas flow due to shock waves, which produces
a desirable side force more lucratively for vectoring. The results from
the parametric studies of the case on hand reveal that the shock
induced self-impinging supersonic secondary double jet is more
efficient in certain locations at the divergent region of a CD nozzle
than a case with supersonic single jet with same mass flow rate. We
observed that the best axial location of the self-impinging supersonic
secondary double jet nozzle with a given jet interaction angle, built-in
to a CD nozzle having area ratio 1.797, is 0.991 times the primary
nozzle throat diameter from the throat location. We also observed
that the flexible steering is possible after invoking ON/OFF facility to
the secondary nozzles for meeting the onboard mission requirements.
Through our case studies we concluded that the supersonic self-impinging
secondary double jet at predesigned jet interaction angle
and location can provide more flexible steering options facilitating
with 8.81% higher thrust vectoring efficiency than the conventional
supersonic single secondary jet without compromising the payload
capability of any supersonic aerospace vehicle.
Abstract: In a practical power system, the power plants are not
located at the same distance from the center of loads and their fuel
costs are different. Also, under normal operating conditions, the
generation capacity is more than the total load demand and losses.
Thus, there are many options for scheduling generation. In an
interconnected power system, the objective is to find the real and
reactive power scheduling of each power plant in such a way as to
minimize the operating cost. This means that the generator’s real and
reactive powers are allowed to vary within certain limits so as to meet
a particular load demand with minimum fuel cost. This is called
optimal power flow problem. In this paper, Economic Load Dispatch
(ELD) of real power generation is considered. Economic Load
Dispatch (ELD) is the scheduling of generators to minimize total
operating cost of generator units subjected to equality constraint of
power balance within the minimum and maximum operating limits of
the generating units. In this paper, genetic algorithms are considered.
ELD solutions are found by solving the conventional load flow
equations while at the same time minimizing the fuel costs.
Abstract: This paper addresses the design of hospital Intensive
Care Unit windows for the achievement of visual comfort and energy
savings. The aim was to identify the window size and shading system
configurations that could fulfill daylighting adequacy, avoid glare
and reduce energy consumption. The study focused on addressing the
effect of utilizing different shading systems in association with a
range of Window-to-Wall Ratios (WWR) in different orientations
under the desert clear-sky of Cairo, Egypt.
The results of this study demonstrated that solar penetration is a
critical concern affecting the design of ICU windows in desert
locations, as in Cairo, Egypt. Use of shading systems was found to be
essential in providing acceptable daylight performance and energy
saving. Careful positioning of the ICU window towards a proper
orientation can dramatically improve performance. It was observed
that ICU windows facing the north direction enjoyed the widest range
of successful window configuration possibilities at different WWRs.
ICU windows facing south enjoyed a reasonable number of
configuration options as well. By contrast, the ICU windows facing
the east orientation had a very limited number of options that provide
acceptable performance. These require additional local shading
measures at certain times due to glare incidence. Moreover, use of
horizontal sun breakers and solar screens to protect the ICU windows
proved to be more successful than the other alternatives in a wide
range of Window to Wall Ratios. By contrast, the use of light shelves
and vertical shading devices seemed questionable.
Abstract: This article discusses event monitoring options for
heterogeneous event sources as they are given in nowadays
heterogeneous distributed information systems. It follows the central
assumption, that a fully generic event monitoring solution cannot
provide complete support for event monitoring; instead, event source
specific semantics such as certain event types or support for certain
event monitoring techniques have to be taken into account.
Following from this, the core result of the work presented here is
the extension of a configurable event monitoring (Web) service for a
variety of event sources. A service approach allows us to trade
genericity for the exploitation of source specific characteristics. It
thus delivers results for the areas of SOA, Web services, CEP and
EDA.