Abstract: The most important problem occurs on oil spills in sea
water is to reduce the oil spills size. This study deals with the
development of high pressurized nozzle using dispersion method for
oil leakage in offshore. 3D numerical simulation results were
obtained using ANSYS Fluent 13.0 code and correlate with the
experimental data for validation. This paper studies the contribution
of the process on flow speed and pressure of the flow from two
different geometrical designs of nozzles and to generate a spray
pattern suitable for dispersant application. Factor of size distribution
of droplets generated by the nozzle is calculated using pressures
ranging from 2 to 6 bars. Results obtain from both analyses shows a
significant spray pattern and flow distribution as well as distance.
Results also show a significant contribution on the effect of oil
leakage in terms of the diameter of the oil spills break up.
Abstract: We present a dedicated video-based monitoring
system for quantification of patient’s attention to visual feedback
during robot assisted gait rehabilitation. Two different approaches for
eye gaze and head pose tracking are tested and compared. Several
metrics for assessment of patient’s attention are also presented.
Experimental results with healthy volunteers demonstrate that
unobtrusive video-based gaze tracking during the robot-assisted gait
rehabilitation is possible and is sufficiently robust for quantification
of patient’s attention and assessment of compliance with the
rehabilitation therapy.
Abstract: This paper proposes a complementary combination scheme of affine projection algorithm (APA) filters with different order of input regressors. A convex combination provides an interesting way to keep the advantage of APA having different order of input regressors. Consequently, a novel APA which has the rapid convergence and the reduced steady-state error is derived. Experimental results show the good properties of the proposed algorithm.
Abstract: Metal matrix composites (MMCs) have gained a
considerable interest in the last three decades. Conventional powder
metallurgy production route often involves the addition of reinforcing
phases into the metal matrix directly, which leads to poor wetting
behavior between ceramic phase and metal matrix and the
segregation of reinforcements. The commonly used elements for
ceramic phase formation in iron based MMCs are Ti, Nb, Mo, W, V
and C, B. The aim of the present paper is to investigate the effect of
sintering temperature and V-B addition on densification, phase
development, microstructure, and hardness of Fe–V-B composites
(Fe-(5-10) wt. %B – 25 wt. %V alloys) prepared by powder
metallurgy process. Metal powder mixes were pressed uniaxial and
sintered at different temperatures (ranging from 1300 to 1400ºC) for
1h. The microstructure of the (V, B) Fe composites was studied with
the help of high magnification optical microscope and XRD.
Experimental results show that (V, B) Fe composites can be produced
by conventional powder metallurgy route.
Abstract: The effect of tillage technology of maize on intensity of weed infestation and weed species composition was observed at experimental field. Maize is grown consecutively since 2001. The experimental site is situated at an altitude of 230 m above sea level in the Czech Republic. Variants of tillage technology are CT: plowing – conventional tillage 0.22 m, MT: loosening – disc tillage on the depth of 0.1 – 0.12 m, NT: direct sowing – without tillage. The evaluation of weed infestation was carried out by numerical method in years 2012 and 2013. Within the monitoring were found 20 various species of weeds. Conventional tillage (CT) primarily supports the occurrence of perennial weeds (Cirsium arvense, Convolvulus arvensis). Late spring species (Chenopodium album, Echinochloa crus-galli) were more frequently noticed on variants of loosening (MT) and direct sowing (NT). Different tillage causes a significant change of weed species spectrum in maize.
Abstract: Vertical slotted walls can be used as permeable
breakwaters to provide economical and environmental protection
from undesirable waves and currents inside the port. The permeable
breakwaters are partially protection and have been suggested to
overcome the environmental disadvantages of fully protection
breakwaters. For regular waves a semi-analytical model is based on
an eigenfunction expansion method and utilizes a boundary condition
at the surface of each wall are developed to detect the energy
dissipation through the slots. Extensive laboratory tests are carried
out to validate the semi-analytic models. The structure of the physical
model contains two walls and it consists of impermeable upper and
lower part, where the draft is based a decimal multiple of the total
depth. The middle part is permeable with a porosity of 50%. The
second barrier is located at a distant of 0.5, 1, 1.5 and 2 times of the
water depth from the first one. A comparison of the theoretical results
with previous studies and experimental measurements of the present
study show a good agreement and that, the semi-analytical model is
able to adequately reproduce most the important features of the
experiment.
Abstract: Virtual reality (VR) is a rapidly emerging computer
interface that attempts to immerse the user completely within an
experimental recreation; thereby, greatly enhancing the overall
impact and providing a much more intuitive link between the
computer and the human participants. The main objective of this
study is to design tractor trailer capable of meeting the customers’
requirements and suitable for rough conditions to be used in
combination with a farm tractor in India. The final concept is capable
of providing arrangements for attaching the trailer to the tractor easily
by pickup hitch, stronger and lighter supporting frame, option of
spare tyre etc. Furthermore, the resulting product design can be sent
via the Internet to customers for comments or marketing purposes.
The virtual prototyping (VP) system therefore facilitates advanced
product design and helps reduce product development time and cost
significantly.
Abstract: The process of thermoforming a carbon fiber reinforced thermoplastic (CFRTP) has increased its presence in the automotive industry for its wide applicability to the mass production car. A non-isothermal forming for CFRTP can shorten its cycle time to less than 1 minute. In this paper, the textile reinforcement FE model which the authors proposed in a previous work is extended to the CFRTP model for non-isothermal forming simulation. The effect of thermoplastic is given by adding shell elements which consider thermal effect to the textile reinforcement model. By applying Reuss model to the stress calculation of thermoplastic, the proposed model can accurately predict in-plane shear behavior, which is the key deformation mode during forming, in the range of the process temperature. Using the proposed model, thermoforming simulation was conducted and the results are in good agreement with the experimental results.
Abstract: The sound pressure level (SPL) of the moving-coil
loudspeaker (MCL) is often simulated and analyzed using the lumped
parameter model. However, the SPL of a MCL cannot be simulated
precisely in the high frequency region, because the value of cone
effective area is changed due to the geometry variation in different
mode shapes, it is also related to affect the acoustic radiation mass and
resistance. Herein, the paper presents the inverse method which has a
high ability to measure the value of cone effective area in various
frequency points, also can estimate the MCL electroacoustic
parameters simultaneously. The proposed inverse method comprises
the direct problem, adjoint problem, and sensitivity problem in
collaboration with nonlinear conjugate gradient method. Estimated
values from the inverse method are validated experimentally which
compared with the measured SPL curve result. Results presented in
this paper not only improve the accuracy of lumped parameter model
but also provide the valuable information on loudspeaker cone design.
Abstract: This study applies the inverse method and three- dimensional CFD commercial software in conjunction with the experimental temperature data to investigate the heat transfer and fluid flow characteristics of the plate-fin heat sink in a closed rectangular enclosure for various values of fin height. The inverse method with the finite difference method and the experimental temperature data is applied to determine the heat transfer coefficient. The k-ε turbulence model is used to obtain the heat transfer and fluid flow characteristics within the fins. To validate the accuracy of the results obtained, the comparison of the average heat transfer coefficient is made. The calculated temperature at selected measurement locations on the plate-fin is also compared with experimental data.
Abstract: The impact deformation and fracture behaviour of cobalt-based Haynes 188 superalloy are investigated by means of a split Hopkinson pressure bar. Impact tests are performed at strain rates ranging from 1×103 s-1 to 5×103 s-1 and temperatures between 25°C and 800°C. The experimental results indicate that the flow response and fracture characteristics of cobalt-based Haynes 188 superalloy are significantly dependent on the strain rate and temperature. The flow stress, work hardening rate and strain rate sensitivity all increase with increasing strain rate or decreasing temperature. It is shown that the impact response of the Haynes 188 specimens is adequately described by the Zerilli-Armstrong fcc model. The fracture analysis results indicate that the Haynes 188 specimens fail predominantly as the result of intensive localised shearing. Furthermore, it is shown that the flow localisation effect leads to the formation of adiabatic shear bands. The fracture surfaces of the deformed Haynes 188 specimens are characterised by dimple- and / or cleavage-like structure with knobby features. The knobby features are thought to be the result of a rise in the local temperature to a value greater than the melting point.
Abstract: In this study, Electrical Discharge Machining (EDM) is used to modify the surface of high carbon steel En31 with the help of tool electrode (Copper-Chromium-Nickel) manufactured by powder metallurgy (PM) process. The effect of EDM on surface roughness during surface alloying is studied. Taguchi’s Design of experiment (DOE) and L18 orthogonal array is used to find the best level of input parameters in order to achieve high surface finish. Six input parameters are considered and their percentage contribution towards surface roughness is investigated by analysis of variances (ANOVA). Experimental results show that an hard alloyed surface (1.21% carbon, 2.14% chromium and 1.38% nickel) with surface roughness of 3.19µm can be generated using EDM with PM tool. Additionally, techniques like Scanning Electron Microscope (SEM) and Energy Dispersive Spectroscopy (EDS) are used to analyze the machined surface and EDMed layer composition, respectively. The increase in machined surface micro-hardness (101%) may be related to the formation of carbides containing chromium.
Abstract: Biomass is renewable and sustainable. As an energy source, it will not release extra carbon dioxide into the atmosphere. Hence, tremendous efforts have been made to develop technologies capable of transforming biomass into suitable forms of bio-fuel. One of the viable technologies is gasifying biomass in supercritical water (SCW), a green medium for reactions. While previous studies overwhelmingly selected glucose as a model compound for biomass, the present study adopted fructose for the sake of comparison. The gasification of fructose in SCW was investigated experimentally to evaluate the applicability of supercritical water processes to biomass gasification. Experiments were conducted with an autoclave reactor. Gaseous product mainly consists of H2, CO, CO2, CH4 and C2H6. The effect of two major operating parameters, the reaction temperature (673-873 K) and the dosage of oxidizing agent (0-0.5 stoichiometric oxygen), on the product gas composition, yield and heating value was also examined, with the reaction pressure fixed at 25 MPa.
Abstract: This paper presents the findings from a numerical simulation of the flow in 37-rod fuel assembly models spaced by a double-wire trapezoidal wrapping as applied to the BREST-OD-300 experimental nuclear reactor. Data on a high static pressure distribution within the models, and equations for determining the fuel bundle flow friction factors have been obtained. Recommendations are provided on using the closing turbulence models available in the ANSYS Fluent. A comparative analysis has been performed against the existing empirical equations for determining the flow friction factors. The calculated and experimental data fit has been shown.
An analysis into the experimental data and results of the numerical simulation of the BREST-OD-300 fuel rod assembly hydrodynamic performance are presented.
Abstract: Effect of blockage ratio on heat transfer from non-circular tube is studied experimentally. For doing this experiment a suction type low speed wind tunnel with test section dimension of 14×14×40 and velocity in rage of 7-20 m/s was designed. The blockage ratios varied between 1.5 to 7 and Reynolds number based on equivalent diameter varies in range of 7.5×103 to 17.5×103. The results show that by increasing blockage ratio from 1.5 to 7, drag coefficient of the cam shaped tube decreased about 55 percent. By increasing Reynolds number, Nusselt number of the cam shaped tube increases about 40 to 48 percent in all ranges of blockage ratios.
Abstract: Ferulic acid has widespread industrial potential by virtue of its antioxidant properties. However, it is partially soluble in aqueous media, limiting their usefulness in oil-based processes in food, cosmetic, pharmaceutical, and material industry. Therefore, modification of ferulic acid should be made by producing of more lipophilic derivatives. In this study, a preliminary investigation of lipase-catalyzed trans-esterification reaction of ethyl ferulate and olive oil was investigated. The reaction was catalyzed by immobilized lipase from Candida antarctica (Novozym 435), to produce ferulate ester, a sunscreen agent. A statistical approach of Response surface methodology (RSM) was used to evaluate the interactive effects of reaction temperature (40-80°C), reaction time (4-12 hours), and amount of enzyme (0.1-0.5 g). The optimum conditions derived via RSM were reaction temperature 60°C, reaction time 2.34 hours, and amount of enzyme 0.3 g. The actual experimental yield was 59.6% ferulate ester under optimum condition, which compared well to the maximum predicted value of 58.0%.
Abstract: Termites have been observed as major pre-colonisation and post-colonisation pest insect of honeybees’ wooden hives in Nigeria. However, pest situation studies in modern beekeeping have been largely directed towards those pests that affect honeybees rather than the biological structure (wood) which houses the honeybees and the influence of seasons on the pests’ activities against the hives. This study, therefore, investigated the influence of seasons on the intensity of hives attacks by termites for 2 years in University of Port Harcourt, Rivers State using visual inspection. The Experimental Apiary was established with 15 Kenyan’s top bar hives made of Triplochiton scleroxylon wood that were strategically placed and observed within the Department of Forestry and Wildlife Management arboretum. The colonies hives consistently showed comparatively lower termite’s infestation levels in the dry season and, consequently, also lower attacks on the colonized hives. The result indicated raining season as a distinct period for more destructive activities of termites on the hives and strongly associated with dryness of the hives. Since previous study and observations have linked colonization with dry season coupled with minimal attacked on colonized hives; the non-colonised hives should be removed from the field at the onset of raining season and returned two weeks prior to dry season to reduce hives degradation by pests.
Abstract: Search is the most obvious application of information
retrieval. The variety of widely obtainable biomedical data is
enormous and is expanding fast. This expansion makes the existing
techniques are not enough to extract the most interesting patterns
from the collection as per the user requirement. Recent researches are
concentrating more on semantic based searching than the traditional
term based searches. Algorithms for semantic searches are
implemented based on the relations exist between the words of the
documents. Ontologies are used as domain knowledge for identifying
the semantic relations as well as to structure the data for effective
information retrieval. Annotation of data with concepts of ontology is
one of the wide-ranging practices for clustering the documents. In
this paper, indexing based on concept and annotation are proposed
for clustering the biomedical documents. Fuzzy c-means (FCM)
clustering algorithm is used to cluster the documents. The
performances of the proposed methods are analyzed with traditional
term based clustering for PubMed articles in five different diseases
communities. The experimental results show that the proposed
methods outperform the term based fuzzy clustering.
Abstract: Effects of insertion of coiled wire in juxtaposition with twisted tapes on heat transfer rate and solar radiation without disturbing the flow inside the riser tubes in a solar flat plate collector is experimentally reconnoitered in this present work. The wire coil used as a turbulator is placed inside the riser tube while the twisted tape is inserted into the wire coil to create a continuous swirling flow along the tube wall. The results of the heat transfer have been compared well with the available results. The heat transfer rate in the collector has been found to be increased by 18% to 70%. Solar water heaters having inserts in the flow tubes perform better than the conventional plain ones. It has been observed that heat losses are reduced consequently increasing the thermal performance about 30% over the plain water heaters under the same operating conditions. The effect of twisted tape with wire coils, flow Reynolds number, and the intensity of solar radiation on the thermal performance of the solar water heater has been presented. Effects of insertion of coiled wire in juxtaposition with twisted tapes on heat transfer rate and solar radiation without disturbing the flow inside the riser tubes in a solar flat plate collector is experimentally reconnoitered in this present work. The wire coil used as a turbulator is placed inside the riser tube while the twisted tape is inserted into the wire coil to create a continuous swirling flow along the tube wall. The results of the heat transfer have been compared well with the available results. The heat transfer rate in the collector has been found to be increased by 18% to 70%. Solar water heaters having inserts in the flow tubes perform better than the conventional plain ones. It has been observed that heat losses are reduced consequently increasing the thermal performance about 30% over the plain water heaters under the same operating conditions. The effect of twisted tape with wire coils, flow Reynolds number, and the intensity of solar radiation on the thermal performance of the solar water heater has been presented.
Abstract: A polypropylene hollow fiber membrane module is used for separating dissolved gases which contain dissolved oxygen from water. These dissolved gases can be used for underwater breathing. To be used for a human, the minimum amount of oxygen is essential. To increase separation of dissolved gases, much water and high surface area of hollow fibers are requested. For efficient separation system, performance of single membrane module with high surface area needs to be investigated.
In this study, we set up experimental devices for analyzing separation characteristics of dissolved gases including oxygen from water using a polypropylene hollow fiber membrane module. Separation of dissolved gases from water is investigated with variations of water flow rates. Composition of dissolved gases is also measured using GC. These results expect to be used in developing the portable separation system.