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: Current systems complexity has reached a degree that
requires addressing conception and design issues while taking into
account environmental, operational, social, legal and financial
aspects. Therefore, one of the main challenges is the way complex
systems are specified and designed. The exponential growing effort,
cost and time investment of complex systems in modeling phase
emphasize the need for a paradigm, a framework and an environment
to handle the system model complexity. For that, it is necessary to
understand the expectations of the human user of the model and his
limits. This paper presents a generic framework for designing
complex systems, highlights the requirements a system model needs
to fulfill to meet human user expectations, and suggests a graphbased
formalism for modeling complex systems. Finally, a set of
transformations are defined to handle the model complexity.
Abstract: Construction projects are information intensive in
nature and involve many activities that are related to each other.
Wireless technologies can be used to improve the accuracy and
timeliness of data collected from construction sites and shares it with
appropriate parties. Nonetheless, the construction industry tends to be
conservative and shows hesitation to adopt new technologies. A main
concern for owners, contractors or any person in charge on a job site
is the cost of the technology in question. Wireless technologies are
not cheap. There are a lot of expenses to be taken into consideration,
and a study should be completed to make sure that the importance
and savings resulting from the usage of this technology is worth the
expenses. This research attempts to assess the effectiveness of using
the appropriate wireless technologies based on criteria such as
performance, reliability, and risk. The assessment is based on a utility
function model that breaks down the selection issue into alternatives
attribute. Then the attributes are assigned weights and single
attributes are measured. Finally, single attribute are combined to
develop one single aggregate utility index for each alternative.
Abstract: We used live E. coli containing synthetic genetic
oscillators to study how the degree of synchrony between the genetic
circuits of sister cells changes with temperature. We found that both
the mean and the variability of the degree of synchrony between the
fluorescence signals from sister cells are affected by temperature.
Also, while most pairs of sister cells were found to be highly
synchronous in each condition, the number of asynchronous pairs
increased with increasing temperature, which was found to be due to
disruptions in the oscillations. Finally we provide evidence that these
disruptions tend to affect multiple generations as opposed to
individual cells. These findings provide insight in how to design
more robust synthetic circuits and in how cell division can affect their
dynamics.
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: In this paper, the cable model of dendrites have been
considered. The dendrites are cylindrical cables of various segments
having variable length and reducing radius from start point at synapse
and end points. For a particular event signal being received by a
neuron in response only some dendrite are active at a particular
instance. Initial current signals with different current flows in
dendrite are assumed. Due to overlapping and coupling of active
dendrite, they induce currents in the dendrite segments of each other
at a particular instance. But how these currents are induced in the
various segments of active dendrites due to coupling between these
dendrites, It is not presented in the literature. Here the paper presents
a model for induced currents in active dendrite segments due to
mutual coupling at the starting instance of an activity in dendrite. The
model is as discussed further.
Abstract: The effect of processing on plasma lipid profile and
atherogenic indices of rats fed Artocarpus heterophyllus seed diets at
different concentrations were investigated. Fifty five rats were used
for this study, they were divided into eleven groups of five rats each
(one control group and ten test groups), the test groups were fed raw,
boiled, roasted, fermented and soaked diets at 10% and 40%
concentrations. The study lasted for thirty five days. The diets led to
significant decrease (p
Abstract: This paper presents a rheological model for producing
shape-memory thermoplastic polymers. Shape-memory occurs as a
result of internal rearrangement of the structural elements of a
polymer. A non-linear viscoelastic model was developed that allows
qualitative and quantitative prediction of the stress-strain behavior of
shape-memory polymers during heating. This research was done to
develop a technique to determine the maximum possible change in
size of shape-memory products during heating. The rheological
model used in this work was particularly suitable for defining process
parameters and constructive parameters of the processing equipment.
Abstract: Mustard leaves are rich in folates, vitamin A, K and
B-complex. Mustard greens are low in calories and fats and rich in
dietary fiber. They are rich in potassium, manganese, iron, copper,
calcium, magnesium and low in sodium. It is very rich in antioxidants
and Phytonutrients. For the optimization of process variables
(moisture content and mustard leave powder), the experiments were
conducted according to central composite Face Centered Composite
design of RSM. The mustard leaves powder was replaced with
composite flour (a combination of rice, chickpea and corn in the ratio
of 70:15:15). The extrudate was extruded in a twin screw extruder at
a barrel temperature of 120°C. The independent variables were
mustard leaves powder (2-10 %) and moisture content (12-20 %).
Responses analyzed were bulk density, water solubility index, water
absorption index, lateral expansion, antioxidant activity, total
phenolic content, and overall acceptability. The optimum conditions
obtained were 7.19 g mustard leaves powder in 100g premix having
16.8% moisture content (w.b).
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.