Abstract: This study is aiming at establishing the relationship
between the optical signal of flame and an equivalent ratio of flame. In
this experiment, flame optical signal in a furnace is measured using
photodiode. The combustion system is composed of metal fiber burner
and vertical furnace, and flame chemiluminescence is measured at
various experimental conditions. In this study, the flame
chemiluminescence of laminar premixed flame is measured using
commercially available photodiode. It is experimentally investigated
the relationship between equivalent ratio and photodiode signal. In
addition, the strategy of combustion control method is proposed using
the optical signal and fuel pressure.
The results showed that certain relationship between optical data of
photodiode and equivalence ratio exists, and this leads to the
successful application of this system for instantaneous measurement of
equivalence ration of the combustion system.
Abstract: When neck pain is associated with pain, numbness, or
weakness in the arm, shoulder, or hand, further investigation is
needed as these are symptoms indicating pressure on one or more
nerve roots. Evaluation necessitates a neurologic examination and
imaging using an MRI/CT scan. A degenerating disc loses some
thickness and is less flexible, causing inter-vertebrae space to narrow.
A radiologist diagnoses an Intervertebral Disc Degeneration (IDD) by
localizing every inter-vertebral disc and identifying the pathology in
a disc based on its geometry and appearance. Accurate localizing is
necessary to diagnose IDD pathology. But, the underlying image
signal is ambiguous: a disc’s intensity overlaps the spinal nerve
fibres. Even the structure changes from case to case, with possible
spinal column bending (scoliosis). The inter-vertebral disc
pathology’s quantitative assessment needs accurate localization of the
cervical region discs. In this work, the efficacy of multilevel set
segmentation model, to segment cervical discs is investigated. The
segmented images are annotated using a simple distance matrix.
Abstract: Pneumatic reactors have been widely employed in various sectors of the chemical industry, especially where are required high heat and mass transfer rates. This study aimed to obtain correlations that allow the prediction of gas hold-up (Ԑ) and volumetric oxygen transfer coefficient (kLa), and compare these values, for three models of pneumatic reactors on two scales utilizing Newtonian fluids. Values of kLa were obtained using the dynamic pressure-step method, while e was used for a new proposed measure. Comparing the three models of reactors studied, it was observed that the mass transfer was superior to draft-tube airlift, reaching e of 0.173 and kLa of 0.00904s-1. All correlations showed good fit to the experimental data (R2≥94%), and comparisons with correlations from the literature demonstrate the need for further similar studies due to shortage of data available, mainly for airlift reactors and high viscosity fluids.
Abstract: Water miscible cutting fluids are conventionally used to lubricate and cool the machining zone. But issues related to health hazards, maintenance and disposal costs have limited their usage, leading to application of Minimum Quantity Lubrication (MQL). To increase the effectiveness of MQL, nanocutting fluids are proposed. In the present work, water miscible nanographite cutting fluids of varying concentration are applied at cutting zone by two systems A and B. System A utilizes high pressure air and supplies cutting fluid at a flow rate of 1ml/min. System B uses low pressure air and supplies cutting fluid at a flow rate of 5ml/min. Their performance in machining is evaluated by measuring cutting temperatures, tool wear, cutting forces and surface roughness and compared with dry machining and flood machining. Application of nanocutting fluid using both systems showed better performance than dry machining. Cutting temperatures and cutting forces obtained by both techniques are more than flood machining. But tool wear and surface roughness showed improvement compared to flood machining. Economic analysis has been carried out in all the cases to decide the applicability of the techniques.
Abstract: In this research, TRACE model of Chinshan BWR/4
nuclear power plant (NPP) has been developed for the simulation and
analysis of ultimate response guideline (URG).The main actions of
URG are the depressurization and low pressure water injection of
reactor and containment venting. This research focuses to verify the
URG efficiency under Fukushima-like conditions. TRACE analysis
results show that the URG can keep the PCT below the criteria
1088.7 K under Fukushima-like conditions. It indicated that Chinshan
NPP was safe.
Abstract: This paper presents a numerical investigation of two
horizontally mounted four-lobed swirl pipes in terms of swirl
induction effectiveness into flows passing through them. The swirl
flows induced by the two swirl pipes have the potential to improve
the efficiency of Clean-In-Place procedures in a closed processing
system by local intensification of hydrodynamic impact on the
internal pipe surface. Pressure losses, swirl development within the
two swirl pipe, swirl induction effectiveness, swirl decay and wall
shear stress variation downstream of two swirl pipes are analyzed and
compared. It was found that a shorter length of swirl inducing pipe
used in joint with transition pipes is more effective in swirl induction
than when a longer one is used, in that it has a less constraint to the
induced swirl and results in slightly higher swirl intensity just
downstream of it with the expense of a smaller pressure loss. The
wall shear stress downstream of the shorter swirl pipe is also slightly
larger than that downstream of the longer swirl pipe due to the
slightly higher swirl intensity induced by the shorter swirl pipe. The
advantage of the shorter swirl pipe in terms of swirl induction is more
significant in flows with a larger Reynolds Number.
Abstract: Advanced treatments such as forward osmosis (FO)
can be used to separate or reject nutrients from secondary treated
effluents. Forward osmosis uses the chemical potential across the
membrane, which is the osmotic pressure gradient, to induce water to
flow through the membrane from a feed solution (FS) into a draw
solution (DS). The performance of FO is affected by the membrane
characteristics, composition of the FS and DS, and operating
conditions. The aim of this study was to investigate the optimum
velocity and temperature for nutrient rejection and water flux
performance in FO treatments. MgCl2 was used as the DS in the FO
process. The results showed that higher cross flow velocities yielded
higher water fluxes. High rejection of nutrients was achieved by using
a moderate cross flow velocity at 0.25 m/s. Nutrient rejection was
insensitive to temperature variation, whereas water flux was
significantly impacted by it. A temperature of 25°C was found to be
good for nutrient rejection.
Abstract: In this paper, we propose a system for preventing gas
risks through the use of wireless communication modules and
intelligent gas safety appliances. Our system configuration consists of
an automatic extinguishing system, detectors, a wall-pad, and a
microcomputer controlled micom gas meter to monitor gas flow and
pressure as well as the occurrence of earthquakes. The automatic fire
extinguishing system checks for both combustible gaseous leaks and
monitors the environmental temperature, while the detector array
measures smoke and CO gas concentrations. Depending on detected
conditions, the micom gas meter cuts off an inner valve and generates
a warning, the automatic fire-extinguishing system cuts off an external
valve and sprays extinguishing materials, or the sensors generate
signals and take further action when smoke or CO are detected.
Information on intelligent measures taken by the gas safety appliances
and sensors are transmitted to the wall-pad, which in turn relays this as
real time data to a server that can be monitored via an external network
(BcN) connection to a web or mobile application for the management
of gas safety. To validate this smart-home gas management system, we
field-tested its suitability for use in Korean apartments under several
scenarios.
Abstract: The secondary alloy A226 is used for many
automotive casting produced by mould casting and high pressure die
casting. This alloy has excellent castability, good mechanical
properties and cost-effectiveness. Production of primary aluminium
alloys belong to heavy source fouling of life environs. The European
Union calls for the emission reduction and reduction in energy
consumption therefore increase production of recycled (secondary)
aluminium cast alloys. The contribution is deal with influence of
recycling on the quality of the casting made from A226 in automotive
industry. The properties of the casting made from secondary
aluminium alloys were compared with the required properties of
primary aluminium alloys. The effect of recycling on microstructure
was observed using combination different analytical techniques (light
microscopy upon black-white etching, scanning electron microscopy
- SEM upon deep etching and energy dispersive X-ray analysis -
EDX). These techniques were used for the identification of the
various structure parameters, which was used to compare secondary
alloy microstructure with primary alloy microstructure.
Abstract: Due to the increasing efforts on saving our natural
environment a change in the structure of energy resources can be
observed - an increasing fraction of a renewable energy sources.
In many countries traditional underground coal mining loses its
significance but there are still countries, like Poland or Germany, in
which the coal based technologies have the greatest fraction in a total
energy production. This necessitates to make an effort to limit the
costs and negative effects of underground coal mining. The longwall
complex is as essential part of the underground coal mining. The
safety and the effectiveness of the work is strongly dependent of the
diagnostic state of powered roof supports.
The building of a useful and reliable diagnostic system requires
a lot of data. As the acquisition of a data of any possible operating
conditions it is important to have a possibility to generate a demanded
artificial working characteristics. In this paper a new approach of
modelling a leg pressure in the single unit of powered roof support.
The model is a result of the analysis of a typical working cycles.
Abstract: An unconventional composite inorganic ceramic
membrane capable of enhancing carbon dioxide emission decline was
fabricated and tested at laboratory scale in conformism to various
environmental guidelines and also to mitigate the effect of global
warming. A review of the existing membrane technologies for carbon
capture including the relevant gas transport mechanisms is presented.
Single gas permeation experiments using silica modified ceramic
membrane with internal diameter 20mm, outside diameter 25mm and
length of 368mm deposited on a macro porous support was carried
out to investigate individual gas permeation behaviours at different
pressures at room temperature. Membrane fabrication was achieved
using after a dip coating method. Nitrogen, Carbon dioxide, Argon,
Oxygen and Methane pure gases were used to investigate their
individual permeation rates at various pressures. Results show that
the gas flow rate increases with pressure drop. However above a
pressure of 3bar, CO2 permeability ratio to that of the other gases
indicated control of a more selective surface adsorptive transport
mechanism.
Abstract: The effect of N2 pretreatment on the catalytic activity
of tungsten-based catalysts was investigated in the metathesis of
ethylene and trans-2-butene at 450oC and atmospheric pressure. The
presence of tungsten active species was confirmed by UV-Vis and
Raman spectroscopy. Compared to the WO3-based catalysts treated
in air, higher amount of WO4 2-tetrahedral species and lower amount
of WO3 crystalline species were observed on the N2-treated ones.
These contribute to the higher conversion of 2-butene and propylene
selectivity during 10 h time-on-stream. Moreover, N2 treatment led to
lower amount of coke formation as revealed by TPO of the spent
catalysts.
Abstract: Due to rapid pressured of population growth, city has
started to lose its old tradition. City becomes congested with
uncomfortably living. Urban renewal refers orderly development of
settlements as well as land redevelopment. For this paper Chittagong
city has been selected as study area. It had a great tradition but it has
been losing its concord. Land use pattern of this place is also
haphazard due to lack of planning intervention. Renewal plan is
needed to ascertain suitable redevelopment and to recommend on
preservation of city heritage structure. The goal of this study is to
prepare a renewal plan using local planning approach. Social impact
methods have been used to achieve this goal. Both primary and
secondary data are used to achieve the goal. This study may find out
a complete solution for healthy living in old Part of city. This study
will help to preserve its tradition and makes urban lives more livable.
Abstract: High pressure turbine (HPT) blades of DV – 2 jet
engines are made from Ni – based superalloy. This alloy was
originally manufactured in the Soviet Union and referred as ŽS6K.
For improving alloy’s high temperature resistance are blades coated
with Al – Si diffusion layer. A regular operation temperature of HPT
blades vary from 705°C to 750°C depending on jet engine regime.
An overcrossing working temperature range causes degradation of
the protective coating as well as base material which microstructure
is formed by the gamma matrix and strengthening phase gamma
prime (forming small particles in the microstructure). Diffusion
processes inside the material during exposition of the material to high
temperatures causes mainly coarsening of the gamma prime particles,
thus decreasing its strengthening effect. Degradation of the Al – Si
coating caused its thickness growth. All the microstructure changes
and coating layer thickness growth results in decreasing of the turbine
blade operation lifetime.
Abstract: Pipa is one of the most important Chinese traditional
plucked instruments, but its directivity has never been measured
systematically. In western, directivity of loudness for western
instruments is deeply researched through analysis of sound pressure
level, whereas the directivity of timbre is seldom studied. In this paper,
a new method for directivity of timbre was proposed, and horizontal
directivity patterns of loudness and timbre of Pipa were measured.
Directivity of Pipa radiation was measured in an anechoic room. The
sound of Pipa played by a musician was recorded simultaneously by
32 microphones with Pipa in the center. The measuring results were
examined through listening test. According to the measurement of
Pipa directivity radiation, we put forward the best localization of Pipa
in the Chinese traditional orchestra and the optimal recording region.
Abstract: This paper is focused on the CFD simulation of the radiaxial pump (i.e. mixed flow pump) with the aim to detect the reasons of Y-Q characteristic instability. The main reasons of pressure pulsations were detected by means of the analysis of velocity and pressure fields within the pump combined with the theoretical approach. Consequently, the modifications of spiral case and pump suction area were made based on the knowledge of flow conditions and the shape of dissipation function. The primary design of pump geometry was created as the base model serving for the comparison of individual modification influences. The basic experimental data are available for this geometry. This approach replaced the more complicated and with respect to convergence of all computational tasks more difficult calculation for the compressible liquid flow. The modification of primary pump consisted in inserting the three fins types. Subsequently, the evaluation of pressure pulsations, specific energy curves and visualization of velocity fields were chosen as the criterion for successful design.
Abstract: Cortisol is essential to the regulation of the immune
system and yawning is a pathological symptom of multiple sclerosis
(MS). Electromyography activity (EMG) in the jaw muscles typically
rises when the muscles are moved and with yawning is highly
correlated with cortisol levels in healthy people. Saliva samples from
59 participants were collected at the start and after yawning, or at the
end of the presentation of yawning-provoking stimuli, in the absence
of a yawn, together with EMG data and questionnaire data: Hospital
Anxiety and Depression Scale, Yawning Susceptibility Scale,
General Health Questionnaire, demographic, health details. Exclusion
criteria: chronic fatigue, diabetes, fibromyalgia, heart condition, high
blood pressure, hormone replacement therapy, multiple sclerosis,
stroke. Significant differences were found between the saliva cortisol
samples for the yawners, t (23) = -4.263, p = 0.000, as compared with
the non-yawners between rest and post-stimuli, which was nonsignificant.
Significant evidence was found to support the Thompson
Cortisol Hypothesis suggesting that rises in cortisol levels are
associated with yawning. Further research is exploring the use of
cortisol as an early diagnostic tool for MS. Ethics approval granted
and professional code of conduct, confidentiality, and safety issues
are approved therein.
Abstract: Hydrothermal liquefaction (HTL) is a technique for obtaining clean biofuel from biomass in the presence of heat and pressure in an aqueous medium which leads to a decomposition of this biomass to the formation of various products. A role of operating conditions is essential for the bio-oil and other products’ yield and also quality of the products. The effects of these parameters were investigated in regards to the composition and yield of the products. Chlorellaceae microalgae were tested under different HTL conditions to clarify suitable conditions for extracting bio-oil together with value-added co-products. Firstly, different microalgae loading rates (5-30%) were tested and found that this parameter has not much significant to product yield. Therefore, 10% microalgae loading rate was selected as a proper economical solution for conditioned schedule at 250oC and 30 min-reaction time. Next, a range of temperature (210-290oC) was applied to verify the effects of each parameter by keeping the reaction time constant at 30 min. The results showed no linkage with the increase of the reaction temperature and some reactions occurred that lead to different product yields. Moreover, some nutrients found in the aqueous product are possible to be utilized for nutrient recovery.
Abstract: This paper presents effects of the mean operating
pressure on the optimal operating frequency based on temperature
differences across stack ends in a thermoacoustic refrigerator. In
addition to the length of the resonance tube, components of the
thermoacoustic refrigerator have an influence on the operating
frequency due to their acoustic properties, i.e., absorptivity,
reflectivity and transmissivity. The interference of waves incurs and
distorts the original frequency generated by the driver so that the
optimal operating frequency differs from the designs. These acoustic
properties are not parameters in the designs and be very complicated
to infer their responses. A prototype thermoacoustic refrigerator is
constructed and used to investigate its optimal operating frequency
compared to the design at various operating pressures. Helium and air
are used as working fluids during the experiments. The results
indicate that the optimal operating frequency of the prototype
thermoacoustic refrigerator using helium is at 6 bar and 490Hz or
approximately 20% away from the design frequency. The optimal
operating frequency at other mean pressures differs from the design
in an unpredictable manner, however, the optimal operating
frequency and pressure can be identified by testing.
Abstract: Scrubbing by a liquid spraying is one of the most
effective processes used for removal of fine particles and soluble
gas pollutants (such as SO2, HCl, HF) from the flue gas. There are
many configurations of scrubbers designed to provide contact
between the liquid and gas stream for effectively capturing
particles or soluble gas pollutants, such as spray plates, packed bed
towers, jet scrubbers, cyclones, vortex and venturi scrubbers. The
primary function of venturi scrubber is the capture of fine particles
as well as HCl, HF or SO2 removal with effect of the flue gas
temperature decrease before input to the absorption column. In this
paper, sulfur dioxide (SO2) from flue gas was captured using new
design replacing venturi scrubber (1st degree of wet scrubbing).
The flue gas was prepared by the combustion of the carbon
disulfide solution in toluene (1:1 vol.) in the flame in the reactor.
Such prepared flue gas with temperature around 150°C was
processed in designed laboratory O-element scrubber. Water was
used as absorbent liquid. The efficiency of SO2 removal, pressure
drop and temperature drop were measured on our experimental
device. The dependence of these variables on liquid-gas ratio was
observed. The average temperature drop was in the range from
150°C to 40°C. The pressure drop was increased with increasing of
a liquid-gas ratio, but no too much as for the common venturi
scrubber designs. The efficiency of SO2 removal was up to 70 %.
The pressure drop of our new designed wet scrubber is similar to
commonly used venturi scrubbers; nevertheless the influence of
amount of the liquid on pressure drop is not so significant.