Abstract: A comparison of activity and stability of the as-formed
Pt/C, Pt-Co and Pt-Pd/C electrocatalysts, prepared by a combined
approach of impregnation and seeding, was performed. According to
the activity test in a single Proton Exchange Membrane (PEM) fuel
cell, the Oxygen Reduction Reaction (ORR) activity of the Pt-M/C
electrocatalyst was slightly lower than that of Pt/C. The j0.9 V and
E10 mA/cm2 of the as-prepared electrocatalysts increased in the order of
Pt/C > Pt-Co/C > Pt-Pd/C. However, in the medium-to-high current
density region, Pt-Pd/C exhibited the best performance. With regard to
their stability in a 0.5 M H2SO4 electrolyte solution, the
electrochemical surface area decreased as the number of rounds of
repetitive potential cycling increased due to the dissolution of the
metals within the catalyst structure. For long-term measurement, Pt-
Pd/C was the most stable than the other three electrocatalysts.
Abstract: This work studies the effect of chemical composition
on the activity and selectivity of γ–alumina supported CuO/
MnO2/Cr2O3 catalysts toward deep oxidation of CO, dimethyl ether
(DME) and methanol. The catalysts were prepared by impregnation
of the support with an aqueous solution of copper nitrate, manganese
nitrate and CrO3 under different conditions. Thermal, XRD and TPR
analysis were performed. The catalytic measurements of single
compounds oxidation were carried out on continuous flow equipment
with a four-channel isothermal stainless steel reactor. Flow-line
equipment with an adiabatic reactor for simultaneous oxidation of all
compounds under the conditions that mimic closely the industrial
ones was used. The reactant and product gases were analyzed by
means of on-line gas chromatographs.
On the basis of XRD analysis it can be concluded that the active
component of the mixed Cu-Mn-Cr/γ–alumina catalysts consists of at
least six compounds – CuO, Cr2O3, MnO2, Cu1.5Mn1.5O4,
Cu1.5Cr1.5O4 and CuCr2O4, depending on the Cu/Mn/Cr molar ratio.
Chemical composition strongly influences catalytic properties, this
influence being quite variable with regards to the different processes.
The rate of CO oxidation rapidly decrease with increasing of
chromium content in the active component while for the DME was
observed the reverse trend. It was concluded that the best
compromise are the catalysts with Cu/(Mn + Cr) molar ratio 1:5 and
Mn/Cr molar ratio from 1:3 to 1:4.
Abstract: Currently, continuous two-phase decanter process
used for olive oil production is the more internationally widespread.
The wastewaters generated from this industry (OMW) are a real
environmental problem because of its high organic load. Among
proposed treatments for these wastewaters, advanced oxidation
technologies (Fenton, ozone, photoFenton, etc.) are the most
favourable. The direct application of these processes is somewhat
expensive. Therefore, the application of a previous stage based on a
flocculation-sedimentation operation is of high importance. In this
research five commercial flocculants (three cationic, and two anionic)
have been used to achieve the separation of phases (liquid clarifiedsludge).
For each flocculant, different concentrations (0-1000 mg/L)
have been studied. In these experiments, sludge volume formed and
the final water quality were determined. The final removal
percentages of total phenols (11.3-25.1%), COD (5.6-20.4%), total
carbon (2.3-26.5%), total organic carbon (1.50-23.8%), total nitrogen
(1.45-24.8%), and turbidity (27.9-61.4%) were determined. The
variation on electric conductivity reduction percentage (1-8%) was
also determined. Finally, the best flocculants with highest removal
percentages have been determined (QG2001 and Flocudex CS49).
Abstract: This paper aims to study the effect of cold work
condition on the microstructure of Cu-1.5wt%Ti, and Cu-3.5wt%Ti
and hence mechanical properties. The samples under investigation
were machined, and solution heat treated. X-ray diffraction technique
is used to identify the different phases present after cold deformation
by compression and also different heat treatment and also measuring
the relative quantities of phases present. The metallographic
examination is used to study the microstructure of the samples. The
hardness measurements were used to indicate the change in
mechanical properties. The results are compared with the mechanical
properties obtained by previous workers. Experiments on cold
compression followed by aging of Cu-Ti alloys have indicated that
the most efficient hardening of the material results from continuous
precipitation of very fine particles within the matrix. These particles
were reported to be β`-type, Cu4Ti phase. The β`-β transformation
and particles coarsening within the matrix as well as long grain
boundaries were responsible for the overaging of Cu-1.5wt%Ti and
Cu-3.5wt%Ti alloys. It is well known that plate-like particles are β –
type, Cu3Ti phase. Discontinuous precipitation was found to start at
the grain boundaries and expand into grain interior. At the higher
aging temperature, a classic Widmanstätten morphology forms giving
rise to a coarse microstructure comprised of α and the equilibrium
phase β. Those results were confirmed by X-ray analysis, which
found that a few percent of Cu3Ti, β precipitates are formed during
aging at high temperature for long time for both Cu- Ti alloys (i.e.
Cu-1.5wt%Ti and Cu-3.5wt%Ti).
Abstract: Evidence shows that start-ups success is positively
correlated with the launch of the first product. However, new ventures
are seldom able to acquire abundant resources for new product
development (NPD), which means that entrepreneurs may depend on
personal creativity instead of physical investments to achieve and
accelerate innovation speed. This study accentuates the role of
entrepreneurial bricolage, which defined as making do by applying
combinations of the resources at hand to new problems and
opportunities, in the relations of creative self-efficacy and innovation
speed. This study uses the multiple regression analysis to test the
hypotheses in a sample of 203 start-ups operating in various creative
markets in Taiwan. Results reveal that creative self-efficacy is
positively and directly associated with innovation speed, whereas
entrepreneurial bricolage plays a full mediator. These findings offer
important theoretical and practical implications.
Abstract: Haynes 25 alloy (also known as L-605 alloy) is cobalt
based super alloy which has widely applications such as aerospace
industry, turbine and furnace parts, power generators and heat
exchangers and petroleum refining components due to its excellent
characteristics. However, the workability of this alloy is more
difficult compared to normal steels or even stainless. In present work,
an experimental investigation was performed under cryogenic
cooling to determine cutting tool wear patterns and obtain optimal
cutting parameters in turning of cobalt based superalloy Haynes 25.
In experiments, uncoated carbide tool was used and cutting speed (V)
and feed rate (f) were considered as test parameters. Tool wear
(VBmax) were measured for process performance indicators.
Analysis of variance (ANOVA) was performed to determine the
importance of machining parameters.
Abstract: Cloud computing has emerged as a promising
direction for cost efficient and reliable service delivery across data
communication networks. The dynamic location of service facilities
and the virtualization of hardware and software elements are stressing
the communication networks and protocols, especially when data
centres are interconnected through the internet. Although the
computing aspects of cloud technologies have been largely
investigated, lower attention has been devoted to the networking
services without involving IT operating overhead. Cloud computing
has enabled elastic and transparent access to infrastructure services
without involving IT operating overhead. Virtualization has been a
key enabler for cloud computing. While resource virtualization and
service abstraction have been widely investigated, networking in
cloud remains a difficult puzzle. Even though network has significant
role in facilitating hybrid cloud scenarios, it hasn't received much
attention in research community until recently. We propose Network
as a Service (NaaS), which forms the basis of unifying public and
private clouds. In this paper, we identify various challenges in
adoption of hybrid cloud. We discuss the design and implementation
of a cloud platform.
Abstract: Amoxicillin is an antibiotic which is widely used to
treat various infections in both human beings and animals. However,
when amoxicillin is released into the environment, it is a major
problem. Amoxicillin causes bacterial resistance to these drugs and
failure of treatment with antibiotics. Liquid membrane is of great
interest as a promising method for the separation and recovery of the
target ions from aqueous solutions due to the use of carriers for the
transport mechanism, resulting in highly selectivity and rapid
transportation of the desired metal ions. The simultaneous processes
of extraction and stripping in a single unit operation of liquid
membrane system are very interesting. Therefore, it is practical to
apply liquid membrane, particularly the HFSLM for industrial
applications as HFSLM is proved to be a separation process with
lower capital and operating costs, low energy and extractant with
long life time, high selectivity and high fluxes compared with solid
membranes. It is a simple design amenable to scaling up for industrial
applications. The extraction and recovery for (Amoxicillin) through
the hollow fiber supported liquid membrane (HFSLM) using
aliquat336 as a carrier were explored with the experimental data. The
important variables affecting on transport of amoxicillin viz.
extractant concentration and operating time were investigated. The
highest AMOX- extraction percentages of 85.35 and Amoxicillin
stripping of 80.04 were achieved with the best condition at 6 mmol/L
[aliquat336] and operating time 100 min. The extraction reaction
order (n) and the extraction reaction rate constant (kf) were found to
be 1.00 and 0.0344 min-1, respectively.
Abstract: In this work new macroporous Ni electrodes modified
with Au nanoparticles for hydrogen production have been developed.
The supporting macroporous Ni electrodes have been obtained by
means of the electrodeposition at high current densities. Then, the Au
nanoparticles were synthesized and added to the electrode surface.
The electrocatalytic behaviour of the developed electrocatalysts was
studied by means of pseudo-steady-state polarization curves,
electrochemical impedance spectroscopy (EIS) and hydrogen
discharge curves. The size of the Au synthetized nanoparticles shows
a monomodal distribution, with a very sharp band between 10 and 50
nm. The characteristic parameters d10, d50 and d90 were 14, 20 and
31 nm respectively. From Tafel polarization data has been concluded
that the Au nanoparticles improve the catalytic activity of the
developed electrodes towards the HER respect to the macroporous Ni
electrodes. EIS permits to obtain the electrochemically active area by
means of the roughness factor value. All the developed electrodes
show roughness factor values in the same order of magnitude. From
the activation energy results it can be concluded that the Au
nanoparticles improve the intrinsic catalytic activity of the
macroporous Ni electrodes.
Abstract: In this paper, the energy saving and human thermal
comfort in a typical office room are investigated. The impact of a
combined system of exhaust inlet air with light slots located at the
ceiling level in a room served by displacement ventilation system is
numerically modelled. Previous experimental data are used to
validate the Computational Fluid Dynamic (CFD) model. A case
study of simulated office room includes two seating occupants, two
computers, two data loggers and four lamps. The combined system is
located at the ceiling level above the heat sources. A new method of
calculation for the cooling coil load in Stratified Air Distribution
(STRAD) system is used in this study. The results show that 47.4%
energy saving of space cooling load can be achieved by combing the
exhaust inlet air with light slots at the ceiling level above the heat
sources.
Abstract: This study aims at developing a novel cold asphalt
concrete binder course mixture by using Ordinary Portland Cement
(OPC) as a replacement for conventional mineral filler (0%-100%)
with new by-product material (LJMU-A2) used as a supplementary
cementitious material. With this purpose, cold asphalt concrete binder
course mixtures with cationic emulsions were studied by means of
stiffness modulus whereas water sensitivity was assessed by
measuring the stiffness modulus ratio before and after sample
conditioning.
The results indicate that a substantial enhancement in the stiffness
modulus and a considerable improvement of water sensitivity
resistance is achieved by adding LJMU-A2 to the cold asphalt
mixtures as a supplementary cementitious material. Moreover, the
addition of LJMU-A2 to those mixtures leads to a stiffness modulus
after 2-day curing compared to that obtained with Portland cement,
which occurs after 7-day curing.
Abstract: The phatic function of communication is a vital
element of any conversation. This research paper looks into this
function with respect to personal blogs maintained by Indian
bloggers. This paper is a study into the phenomenon of phatic
communication maintained by bloggers through their blogs. Based on
a linguistic analysis of the posts of twenty eight Indian bloggers,
writing in English, studied over a period of three years, the study
indicates that though the blogging phenomenon is not conversational
in the same manner as face-to-face communication, it does make
ample provision for feedback that is conversational in nature.
Ordinary day to day offline conversations use conventionalized
phatic utterances; those on the social media are in a perpetual mode
of innovation and experimentation in order to sustain contact with its
readers. These innovative methods and means are the focus of this
study. Though the personal blogger aims to chronicle his/her personal
life through the blog, the socializing function is crucial to these
bloggers. In comparison to the western personal blogs which focus on
the presentation of the ‘bounded individual self’, we find Indian
personal bloggers engage in the presentation of their ‘social selves’.
These bloggers yearn to reach out to the readers on the internet and
the phatic function serves to initiate, sustain and renew social ties on
the blogosphere thereby consolidating the social network of readers
and bloggers.
Abstract: Mitigating soil erosion, especially in Mediterranean
countries such as Greece, is essential in order to maintain
environmental and agricultural sustainability. In this paper, scientific
publications related to soil erosion studies in Greece were reviewed
and categorized. To accomplish this, the online search engine of
Scopus was used. The key words were “soil”, “erosion” and
“Greece.” An analysis of the published articles was conducted at
three levels: i) type of publication, ii) chronologic and iii) thematic. A
hundred and ten publications published in scientific journals were
reviewed. The results showed that the awareness regarding the soil
erosion in Greece has increased only in the last decades. The
publications covered a wide range of thematic categories such as the
type of studied areas, the physical phenomena that trigger and
influence the soil erosion, the negative anthropogenic impacts on
them, the assessment tools that were used in order to examine the
threat and the proper management. The analysis of these articles was
significant and necessary in order to find the scientific gaps of soil
erosion studies in Greece and help enhance the sustainability of soil
management in the future.
Abstract: Most of the oil palm plantations have been threatened
by Basal Stem Rot (BSR) disease which causes serious economic
impact. This study was conducted to identify the healthy and BSRinfected
oil palm tree using thirteen color indices. Multispectral and
thermal camera was used to capture 216 images of the leaves taken
from frond number 1, 9 and 17. Indices of normalized difference
vegetation index (NDVI), red (R), green (G), blue (B), near infrared
(NIR), green – blue (GB), green/blue (G/B), green – red (GR),
green/red (G/R), hue (H), saturation (S), intensity (I) and thermal
index (T) were used. From this study, it can be concluded that G
index taken from frond number 9 is the best index to differentiate
between the healthy and BSR-infected oil palm trees. It not only gave
high value of correlation coefficient (R=-0.962), but also high value
of separation between healthy and BSR-infected oil palm tree.
Furthermore, power and S model developed using G index gave the
highest R2 value which is 0.985.
Abstract: This initial study is concerned with the behavior of
engineering students in Kuwait University which became a concern
due to the global issues of education in all levels. A survey has been
conducted to identify academic and societal issues affecting the
engineering student performance. The study is drawing major
conclusions with regard to private tutoring and the online availability
of textbooks’ solution manuals.
Abstract: This paper presents Carrier Sense Multiple Access
(CSMA) communication models based on SoC design methodology.
Such a model can be used to support the modeling of the complex
wireless communication systems. Therefore, the use of such
communication model is an important technique in the construction
of high-performance communication. SystemC has been chosen
because it provides a homogeneous design flow for complex designs
(i.e. SoC and IP-based design). We use a swarm system to validate
CSMA designed model and to show how advantages of incorporating
communication early in the design process. The wireless
communication created through the modeling of CSMA protocol that
can be used to achieve communication between all the agents and to
coordinate access to the shared medium (channel).
Abstract: Interstitial free steels possess better formability and
have many applications in automotive industries. Forming limit
diagrams (FLDs) indicate the formability of materials which can be
determined by experimental and finite element (FE) simulations.
FLDs were determined experimentally by LDH test, utilizing optical
strain measurement system for measuring the strains in different
width specimens and by FE simulations in Interstitial Free (IF) and
Interstitial Free High Strength (IFHS) steels. In this study, the
experimental and FE simulated FLDs are compared and also the
stress based FLDs were investigated.
Abstract: The Chair of Thermal Engineering at Poznan
University of Technology has been conducted research works on the
possibilities of using carbon nanostructures in energy and mechanics
applications for a couple of years. Those studies have provided results in a form of co-operation with foreign research centres, numerous publications and patent
applications.
Authors of this paper have studied the influence of multi-walled
carbon nanostructures on changes in static friction arising when steel
surfaces were moved. Tests were made using the original test stand
consisting of automatically controlled inclined plane driven by
precise stepper motors. Computer program created in the LabView
environment was responsible for monitoring of the stand operation,
accuracy of measurements and archiving the obtained results. Such a
solution enabled to obtain high accuracy and repeatability of all
conducted experiments.
Tests and analysis of the obtained results allowed us to determine
how additional layers of carbon nanostructures influenced on changes
of static friction coefficients. At the same time, we analyzed the
potential possibilities of applying nanostructures under consideration
in mechanics.
Abstract: One of the functions of the commercial heavy vehicle
is to safely and efficiently transport goods and people. Due to its size
and carrying capacity, it is important to study the vehicle dynamic
stability during cornering. Study has shown that there are a number of
overloaded heavy vehicles or permissible Gross Vehicle Weight
(GVW) violations recorded at selected areas in Malaysia assigned by
its type and category. Thus, the objective of this study is to
investigate the correlation and effect of the GVW on heavy vehicle
stability during cornering event using simulation. Various selected
heavy vehicle types and category are simulated using IPG/Truck
Maker® with different GVW and road condition (coefficient of
friction of road surface), while the speed, driver characteristic, center
of gravity of load and road geometry are constant. Based on the
analysis, the relationship between GVW and lateral acceleration were
established. As expected, on the same value of coefficient of friction,
the maximum lateral acceleration would be increased as the GVW
increases.
Abstract: Mobil Producing Nigeria Unlimited (MPNU), a
subsidiary of ExxonMobil and the highest crude oil & condensate
producer in Nigeria has its operational base and an oil terminal, the
Qua Iboe terminal (QIT) located at Ibeno, Nigeria. Other oil
companies like Network Exploration and Production Nigeria Ltd,
Frontier Oil Ltd; Shell Petroleum Development Company Ltd; Elf
Petroleum Nigeria Ltd and Nigerian Agip Energy, a subsidiary of the
Italian ENI E&P operate onshore, on the continental shelf and in deep
offshore of the Atlantic Ocean, respectively with the coastal waters of
Ibeno, Nigeria as the nearest shoreline. This study was designed to
delineate the oil-polluted sites in Ibeno, Nigeria using
microbiological and physico-chemical characterization of soils,
sediments and ground and surface water samples from the study area.
Results obtained revealed that there have been significant recent
hydrocarbon inputs into this environment as observed from the high
counts of hydrocarbonoclastic microorganisms in excess of 1% at all
the stations sampled. Moreover, high concentrations of THC, BTEX
and heavy metals contents in all the samples analyzed corroborate the
high recent crude oil input into the study area. The results also
showed that the pollution of the different environmental media
sampled were of varying degrees, following the trend: ground water
> surface water > sediments > soils.