Abstract: In this study, composites were fabricated from oil
palm empty fruit bunch fiber and poly(lactic) acid by extrusion
followed by injection moulding. Surface of the fiber was pre-treated
by ultrasound in an alkali medium and treatment efficiency was
investigated by scanning electron microscopy (SEM) analysis and
Fourier transforms infrared spectrometer (FTIR). Effect of fiber
treatment on composite was characterized by tensile strength (TS),
tensile modulus (TM) and impact strength (IS). Furthermore,
biostrong impact modifier was incorporated into the treated fiber
composite to improve its impact properties. Mechanical testing
showed an improvement of up to 23.5% and 33.6% respectively for
TS and TM of treated fiber composite above untreated fiber
composite. On the other hand incorporation of impact modifier led to
enhancement of about 20% above the initial IS of the treated fiber
composite.
Abstract: The current study investigated the influence of milling
time and ball-to-powder (BPR) weight ratio on the microstructural
constituents and mechanical properties of bulk nanocrystalline Al;
Al-10%Cu; and Al-10%Cu-5%Ti alloys. Powder consolidation was
carried out using a high frequency induction heat sintering where the
processed metal powders were sintered into a dense and strong bulk
material. The powders and the bulk samples were characterized using
XRD and FEGSEM techniques. The mechanical properties were
evaluated at various temperatures of 25°C, 100°C, 200°C, 300°C and
400°C to study the thermal stability of the processed alloys. The
processed bulk nanocrystalline alloys displayed extremely high
hardness values even at elevated temperatures. The Al-10%Cu-5%Ti
alloy displayed the highest hardness values at room and elevated
temperatures which are related to the presence of Ti-containing
phases such as Al3Ti and AlCu2Ti. These phases are thermally stable
and retain the high hardness values at elevated temperatures up to
400ºC.
Abstract: The present study was undertaken to investigate the
effect of pre-aging and aging parameters (time and temperature) on
the mechanical properties of Al-Mg-Zn (7075) alloys. Ultimate
tensile strength, 0.5% offset yield strength and % elongation
measurements were carried out on specimens prepared from cast and
heat treated 7075 alloys. Aging treatments were carried out for the as
solution treated (SHT) specimens (after quenching in warm water).
The specimens were aged at different conditions; Natural aging was
carried out at room temperature for different periods of time. Double
aging was performed for SHT conditions (pre-aged at different time
and temperature followed by high temperature aging). Ultimate
tensile strength, yield strength and % elongation as a function of
different pre-aging and aging parameters are analyzed to acquire an
understanding of the effects of these variables and their interactions
on the mechanical properties of Be-treated 7075 alloys.
Abstract: In this article is reported a construction and some
properties of the 5iD viewer, the system recording simultaneously
5 views of a given experimental object. Properties of the system
are demonstrated on the analysis of fish schooling behaviour. It
is demonstrated the method of instrument calibration which allows
inclusion of image distortion and it is proposed and partly tested
also the method of distance assessment in the case that only two
opposite cameras are available. Finally, we demonstrate how the state
trajectory of the behaviour of the fish school may be constructed from
the entropy of the system.
Abstract: Parameters of flow are calculated in vaneless diffusers
with relative width 0,014–0,10. Inlet angles of flow and similarity
criteria were varied. There is information on flow separation,
boundary layer development, configuration of streamlines.
Polytrophic efficiency, loss coefficient and recovery coefficient are
used to compare effectiveness of diffusers. The sample of
optimization of narrow diffuser with conical walls is presented. Three
wide diffusers with narrowing walls are compared. The work is made
in the R&D laboratory “Gas dynamics of turbo machines” of the TU
SPb.
Abstract: This paper presents a novel fractal antenna structure
proposed for UWB (Ultra – Wideband) applications. The frequency
band 3.1-10.6GHz released by FCC (Federal Communication
Commission) as the commercial operation of UWB has been chosen
as frequency range for this antenna based on coplanar waveguide
(CPW) feed and circular shapes fulfilled according to fractal
geometry. The proposed antenna is validated and designed by using
an FR4 substrate with overall area of 34x43 mm2. The simulated
results performed by CST-Microwave Studio and compared by ADS
(Advanced Design System) show good matching input impedance
with return loss less than -10dB between 2.9 GHz and 11 GHz.
Abstract: Universal modeling method well proven for industrial
compressors was applied for design of the high flow rate supersonic
stage. Results were checked by ANSYS CFX and NUMECA Fine
Turbo calculations. The impeller appeared to be very effective at
transonic flow velocities. Stator elements efficiency is acceptable at
design Mach numbers too. Their loss coefficient versus inlet flow
angle performances correlates well with Universal modeling
prediction. The impeller demonstrates ability of satisfactory operation
at design flow rate. Supersonic flow behavior in the impeller inducer
at the shroud blade to blade surface Φ des deserves additional study.
Abstract: There is an evident trend to elevate pressure ratio of a
single stage of a turbo compressors - axial compressors in particular.
Whilst there was an opinion recently that a pressure ratio 1,9 was a
reasonable limit, later appeared information on successful modeling
tested of stages with pressure ratio up to 2,8. The authors recon that
lack of information on high pressure stages makes actual a study of
rational choice of design parameters before high supersonic flow
problems solving. The computer program of an engineering type was
developed. Below is presented a sample of its application to study
possible parameters of the impeller of the stage with pressure ratio
3,0. Influence of two main design parameters on expected efficiency,
periphery blade speed and flow structure is demonstrated. The results
had lead to choose a variant for further analysis and improvement by
CFD methods.
Abstract: The continuous decline of petroleum and natural gas
reserves and non linear rise of oil price has brought about a
realisation of the need for a change in our perpetual dependence on
the fossil fuel. A day to day increased consumption of crude and
petroleum products has made a considerable impact on our foreign
exchange reserves. Hence, an alternate resource for the conversion of
energy (both liquid and gas) is essential for the substitution of
conventional fuels. Biomass is the alternate solution for the present
scenario. Biomass can be converted into both liquid as well as
gaseous fuels and other feedstocks for the industries.
Abstract: Vancron 40, a nitrided powder metallurgical tool
Steel, is used in cold work applications where the predominant failure
mechanisms are adhesive wear or galling. Typical applications of
Vancron 40 are among others fine blanking, cold extrusion, deep
drawing and cold work rolls for cluster mills. Vancron 40 positive
results for cold work rolls for cluster mills and as a tool for some
severe metal forming process makes it competitive compared to other
type of work rolls that require higher precision, among others in cold
rolling of thin stainless steel, which required high surface finish
quality. In this project, three roll materials for cold rolling of stainless
steel strip was examined, Vancron 40, Narva 12B (a high-carbon,
high-chromium tool steel alloyed with tungsten) and Supra 3 (a
Chromium-molybdenum tungsten-vanadium alloyed high speed
steel). The purpose of this project was to study the depth profiles of
the ironed stainless steel strips, emergence of galling and to study the
lubrication performance used by steel industries. Laboratory
experiments were conducted to examine scratch of the strip, galling
and surface roughness of the roll materials under severe tribological
conditions. The critical sliding length for onset of galling was
estimated for stainless steel with four different lubricants. Laboratory
experiments result of performance evaluation of resistance capability
of rolls toward adhesive wear under severe conditions for low and
high reductions. Vancron 40 in combination with cold rolling
lubricant gave good surface quality, prevents galling of
metal surfaces and good bearing capacity.
Abstract: This paper introduces novel approaches to partitioning
and mapping in terms of model-based embedded multicore system
engineering and further discusses benefits, industrial relevance and
features in common with existing approaches. In order to assess
and evaluate results, both approaches have been applied to a real
industrial application as well as to various prototypical demonstrative
applications, that have been developed and implemented for
different purposes. Evaluations show, that such applications improve
significantly according to performance, energy efficiency, meeting
timing constraints and covering maintaining issues by using
the AMALTHEA platform and the implemented approaches.
Furthermore, the model-based design provides an open, expandable,
platform independent and scalable exchange format between
OEMs, suppliers and developers on different levels. Our proposed
mechanisms provide meaningful multicore system utilization since
load balancing by means of partitioning and mapping is effectively
performed with regard to the modeled systems including hardware,
software, operating system, scheduling, constraints, configuration and
more data.
Abstract: Many issues about the relationship between auditors in
auditing practices with its stakeholders often heard. It appears in
perspectives of bringing out the variety of phenomena affecting from
the audit practice of greed and not appreciating from the
independency of the audit profession and professional code of ethics.
It becomes a logical consequence in practicing of capitalism in
accounting. The main purpose of this article would like to uncover
the existing auditing practices in Indonesia, especially in Java that
associated with a strong influence of Javanese culture with reluctant
/”shy", politely, "legowo (gratefully accepted)", "ngemong"
(friendly), "not mentholo" (lenient), "tepo seliro" (tolerance),
"ngajeni" (respectful), "acquiescent" and also reveals its relationships
with Non Javanese culture in facing the conflict of interest in
practical of auditing world. The method used by interpretive
approach that emphasizes the role of language, interpret and
understand and see social reality as something other than a label,
name or concept. Global practices in auditing of each country have
particular cultures that affect the standard set by those regulatory
standards results the adaptation of IAS. The majority of parties in
Indonesia is dominated by Javanese racial regulators, so Java culture
is embedded in every audit practices and those conditions in Java
leads auditors in having similar behaviour, sometimes interfere with
standard Java code of conduct must be executed by an auditor.
Auditors who live in Java have the characters of Javanese culture that
is hard to avoid in the audit practice. However, practically, the
auditors still are relevant in their profession.
Abstract: The mechanics of rip currents are complex, involving
interactions between waves, currents, water levels and the bathymetry,
that present particular challenges for numerical models. Here,
the effects of a grid-spacing dependent horizontal mixing on the
wave-current interactions are studied. Near the shore, wave rays
diverge from channels towards bar crests because of refraction by
topography and currents, in a way that depends on the rip current
intensity which is itself modulated by the horizontal mixing. At
low resolution with the grid-spacing dependent horizontal mixing,
the wave motion is the same for both coupling modes because the
wave deviation by the currents is weak. In high resolution case,
however, classical results are found with the stabilizing effect of
the flow by feedback of waves on currents. Lastly, wave-current
interactions and the horizontal mixing strongly affect the intensity
of the three-dimensional rip velocity.
Abstract: Member States shall establish zones and
agglomerations throughout their territory to assess and manage air
quality in order to comply with European directives.
In Italy decree 155/2010, transposing Directive 2008/50/EC on
ambient air quality and cleaner air for Europe, merged into a single
act the previous provisions on ambient air quality assessment and
management, including those resulting from the implementation of
Directive 2004/107/EC relating to arsenic, cadmium, nickel, mercury
and polycyclic aromatic hydrocarbons in ambient air.
Decree 155/2010 introduced stricter rules for identifying zones on
the basis of the characteristics of the territory in spite of considering
pollution levels, as it was in the past. The implementation of such
new criteria has reduced the great variability of the previous zoning,
leading to a significant reduction of the total number of zones and to
a complete and uniform ambient air quality assessment and
management throughout the Country.
The present document is related to the new zones definition in
Italy according to Decree 155/2010. In particular the paper contains
the description and the analysis of the outcome of zoning and
classification.
Abstract: Physics Education Research (PER) results have shown
that students do not achieve the expected level of competency in
understanding the concepts of different domains of Physics learning
when taught by the traditional teaching methods, the concepts of
Electricity and Magnetism (E&M) being one among them.
Simulation being one of the valuable instructional tools renders an
opportunity to visualize varied experiences with such concepts.
Considering the electric force concept which requires extensive use
of vector representations, we report here the outcome of the research
results pertaining to the student understanding of this concept and the
role of simulation in using vector representation. The simulation
platform provides a positive impact on the use of vector
representation.
The first stage of this study involves eliciting and analyzing
student responses to questions that probe their understanding of the
concept of electrostatic force and this is followed by four stages of
student interviews as they use the interactive simulations of electric
force in one dimension. Student responses to the questions are
recorded in real time using electronic pad. A validation test interview
is conducted to evaluate students' understanding of the electric force
concept after using interactive simulation. Results indicate lack of
procedural knowledge of the vector representation. The study
emphasizes the need for the choice of appropriate simulation and
mode of induction for learning.
Abstract: Building loss estimation methodologies which have
been advanced considerably in recent decades are usually used to
estimate socio and economic impacts resulting from seismic structural
damage. In accordance with these methods, this paper presents the
evaluation of an annual loss probability of a reinforced concrete
moment resisting frame designed according to Korean Building Code.
The annual loss probability is defined by (1) a fragility curve obtained
from a capacity spectrum method which is similar to a method adopted
from HAZUS, and (2) a seismic hazard curve derived from annual
frequencies of exceedance per peak ground acceleration. Seismic
fragilities are computed to calculate the annual loss probability of a
certain structure using functions depending on structural capacity,
seismic demand, structural response and the probability of exceeding
damage state thresholds. This study carried out a nonlinear static
analysis to obtain the capacity of a RC moment resisting frame
selected as a prototype building. The analysis results show that the
probability of being extensive structural damage in the prototype
building is expected to 0.01% in a year.
Abstract: The spring-driven ball-type check valve is one of the
most important components of hydraulic systems: it controls the
position of the ball and prevents backward flow. To simplify the
structure, the spring must be eliminated, and to accomplish this, the
flow pattern and the behavior of the check ball in L-shaped pipe must
be determined. In this paper, we present a full-scale model of a check
ball made of acrylic resin, and we determine the relationship between
the initial position of the ball, the position and diameter of the inflow
port. The check flow rate increases in a standard center inflow model,
and it is possible to greatly decrease the check-flow rate by shifting the
inflow from the center.
Abstract: Conventional educational practices, do not offer all
the required skills for teachers to successfully survive in today’s
workplace. Due to poor professional training, a big gap exists across
the curriculum plan and the teacher practices in the classroom. As
such, raising the quality of teaching through ICT-enabled training and
professional development of teachers should be an urgent priority.
‘Mobile Learning’, in that vein, is an increasingly growing field of
educational research and practice across schools and work places. In
this paper, we propose a novel Mobile learning system that allows the
users to learn through an intelligent mobile learning in cooperatively
every-time and every-where. The system will reduce the training cost
and increase consistency, efficiency, and data reliability. To establish
that our system will display neither functional nor performance
failure, the evaluation strategy is based on formal observation of
users interacting with system followed by questionnaires and
structured interviews.
Abstract: The prepreg process among the CFRP (Carbon Fiber
Reinforced Plastic) forming methods is the short term of
‘Pre-impregnation’, which is widely used for aerospace composites
that require a high quality property such as a fiber-reinforced woven
fabric, in which an epoxy hardening resin is impregnated the reality.
However, that this process requires continuous researches and
developments for its commercialization because the delamination
characteristically develops between the layers when a great weight is
loaded from outside to supplement such demerit, three lamination
methods among the prepreg lamination methods of CFRP were
designed to minimize the delamination between the layers due to
external impacts. Further, the newly designed methods and the
existing lamination methods were analyzed through a mechanical
characteristic test, Interlaminar Shear Strength test. The Interlaminar
Shear Strength test result confirmed that the newly proposed three
lamination methods, i.e. the Roll, Half and Zigzag laminations,
presented more excellent strengths compared to the conventional Ply
lamination. The interlaminar shear strength in the roll method with
relatively dense fiber distribution was approximately 1.75% higher
than that in the existing ply lamination method, and in the half method,
it was approximately 0.78% higher.
Abstract: Bacterial strains capable of degradation of malathion
from the domestic sewage were isolated by an enrichment culture
technique. Three bacterial strains were screened and identified as
Acinetobacter baumannii (AFA), Pseudomonas aeruginosa (PS1),
and Pseudomonas mendocina (PS2) based on morphological,
biochemical identification and 16S rRNA sequence analysis.
Acinetobacter baumannii AFA was the most efficient malathion
degrading bacterium, so used for further biodegradation study. AFA
was able to grow in mineral salt medium (MSM) supplemented with
malathion (100 mg/l) as a sole carbon source, and within 14 days,
84% of the initial dose was degraded by the isolate measured by high
performance liquid chromatography. Strain AFA could also degrade
other organophosphorus compounds including diazinon, chlorpyrifos
and fenitrothion. The effect of different culture conditions on the
degradation of malathion like inoculum density, other carbon or
nitrogen sources, temperature and shaking were examined.
Degradation of malathion and bacterial cell growth were accelerated
when culture media were supplemented with yeast extract, glucose
and citrate. The optimum conditions for malathion degradation by
strain AFA were; an inoculum density of 1.5x 10^12CFU/ml at 30°C
with shaking. A specific polymerase chain reaction primers were
designed manually using multiple sequence alignment of the
corresponding carboxylesterase enzymes of Acinetobacter species.
Sequencing result of amplified PCR product and phylogenetic
analysis showed low degree of homology with the other
carboxylesterase enzymes of Acinetobacter strains, so we suggested
that this enzyme is a novel esterase enzyme. Isolated bacterial strains
may have potential role for use in bioremediation of malathion
contaminated.