Abstract: In this paper, an explicit homotopic function is
constructed to compute the Hochschild homology of a finite
dimensional free k-module V. Because the polynomial algebra is of
course fundamental in the computation of the Hochschild homology
HH and the cyclic homology CH of commutative algebras, we
concentrate our work to compute HH of the polynomial algebra, by
providing certain homotopic function.
Abstract: Activated carbons (M4P0, M4P2, and M5P2) used in
this research were produced from palm shell and polyetherether
ketone (PEEK) via carbonization, impregnation and microwave
activation. The adsorption/desorption process was carried out using
static volumetric adsorption. Regeneration is important in the overall
economy of the process and waste minimization. This work focuses
on the thermal regeneration of the CO2 exhausted microwave
activated carbons. The regeneration strategy adopted was thermal
with nitrogen purge desorption with N2 feed flow rate of 20 ml/min
for 1 h at atmospheric pressure followed by drying at 150oC.Seven
successive adsorption/regeneration processes were carried out on the
material. It was found that after seven adsorption regeneration cycles;
the regeneration efficiency (RE) for CO2 activated carbon from palm
shell only (M4P0) was more than 90% while that of hybrid palm
shell-PEEK (M4P2, M5P2) was above 95%. The cyclic adsorption
and regeneration shows the stability of the adsorbent materials.
Abstract: Poly vinyl acetate (PVA)-based titania (TiO2)–carbon
nanotube composite nanofibers (PVA-TCCNs) with various
PVA-to-solvent ratios and PVA-based TiO2 composite nanofibers
(PVA-TN) were synthesized using an electrospinning process,
followed by thermal treatment. The photocatalytic activities of these
nanofibers in the degradation of airborne monocyclic aromatics under
visible-light irradiation were examined. This study focuses on the
application of these photocatalysts to the degradation of the target
compounds at sub-part-per-million indoor air concentrations. The
characteristics of the photocatalysts were examined using scanning
electron microscopy, X-ray diffraction, ultraviolet-visible
spectroscopy, and Fourier-transform infrared spectroscopy. For all the
target compounds, the PVA-TCCNs showed photocatalytic
degradation efficiencies superior to those of the reference PVA-TN.
Specifically, the average photocatalytic degradation efficiencies for
benzene, toluene, ethyl benzene, and o-xylene (BTEX) obtained using
the PVA-TCCNs with a PVA-to-solvent ratio of 0.3 (PVA-TCCN-0.3)
were 11%, 59%, 89%, and 92%, respectively, whereas those observed
using PVA-TNs were 5%, 9%, 28%, and 32%, respectively.
PVA-TCCN-0.3 displayed the highest photocatalytic degradation
efficiency for BTEX, suggesting the presence of an optimal
PVA-to-solvent ratio for the synthesis of PVA-TCCNs. The average
photocatalytic efficiencies for BTEX decreased from 11% to 4%, 59%
to 18%, 89% to 37%, and 92% to 53%, respectively, when the flow
rate was increased from 1.0 to 4.0 L min1. In addition, the average
photocatalytic efficiencies for BTEX increased 11% to ~0%, 59% to
3%, 89% to 7%, and 92% to 13%, respectively, when the input
concentration increased from 0.1 to 1.0 ppm. The prepared
PVA-TCCNs were effective for the purification of airborne aromatics
at indoor concentration levels, particularly when the operating
conditions were optimized.
Abstract: Natural hydrocarbon seepage has helped petroleum
exploration as a direct indicator of gas and/or oil subsurface
accumulations. Surface macro-seeps are generally an indication of a
fault in an active Petroleum Seepage System belonging to a Total
Petroleum System. This paper describes a case study in which
multiple analytical techniques were used to identify and characterize
trace petroleum-related hydrocarbons and other volatile organic
compounds in groundwater samples collected from Sousse aquifer
(Central Tunisia). The analytical techniques used for analyses of
water samples included gas chromatography-mass spectrometry (GCMS),
capillary GC with flame-ionization detection, Compound
Specific Isotope Analysis, Rock Eval Pyrolysis. The objective of the
study was to confirm the presence of gasoline and other petroleum
products or other volatile organic pollutants in those samples in order
to assess the respective implication of each of the potentially
responsible parties to the contamination of the aquifer. In addition,
the degree of contamination at different depths in the aquifer was also
of interest. The oil and gas seeps have been investigated using
biomarker and stable carbon isotope analyses to perform oil-oil and
oil-source rock correlations. The seepage gases are characterized by
high CH4 content, very low δ13CCH4 values (-71,9 ‰) and high
C1/C1–5 ratios (0.95–1.0), light deuterium–hydrogen isotope ratios (-
198 ‰) and light δ13CC2 and δ13CCO2 values (-23,8‰ and-23,8‰
respectively) indicating a thermogenic origin with the contribution of
the biogenic gas. An organic geochemistry study was carried out on
the more ten oil seep samples. This study includes light hydrocarbon
and biomarkers analyses (hopanes, steranes, n-alkanes, acyclic
isoprenoids, and aromatic steroids) using GC and GC-MS. The
studied samples show at least two distinct families, suggesting two
different types of crude oil origins: the first oil seeps appears to be
highly mature, showing evidence of chemical and/or biological
degradation and was derived from a clay-rich source rock deposited
in suboxic conditions. It has been sourced mainly by the lower
Fahdene (Albian) source rocks. The second oil seeps was derived
from a carbonate-rich source rock deposited in anoxic conditions,
well correlated with the Bahloul (Cenomanian-Turonian) source rock.
Abstract: Polycyclic aromatic hydrocarbons (PAHs) are formed
during the pyrolysis of scrap tyres to produce tyre pyrolytic oil
(TPO). Due to carcinogenic, mutagenic, and toxic properties PAHs
are priority pollutants. Hence it is essential to remove PAHs from
TPO before utilising TPO as a petroleum fuel alternative (to run the
engine). Agricultural wastes have promising future to be utilized as
biosorbent due to their cost effectiveness, abundant availability, high
biosorption capacity and renewability. Various low cost adsorbents
were prepared from natural sources. Uptake of PAHs present in tyre
pyrolytic oil was investigated using various low-cost adsorbents of
natural origin including sawdust (shisham), coconut fiber, neem bark,
chitin, activated charcoal. Adsorption experiments of different PAHs
viz. naphthalene, acenaphthalene, biphenyl and anthracene have been
carried out at ambient temperature (25°C) and at pH 7. It was
observed that for any given PAH, the adsorption capacity increases
with the lignin content. Freundlich constant Kf and 1/n have been
evaluated and it was found that the adsorption isotherms of PAHs
were in agreement with a Freundlich model, while the uptake
capacity of PAHs followed the order: activated charcoal> saw dust
(shisham) > coconut fiber > chitin. The partition coefficients in
acetone-water, and the adsorption constants at equilibrium, could be
linearly correlated with octanol–water partition coefficients. It is
observed that natural adsorbents are good alternative for PAHs
removal. Sawdust of Dalbergia sissoo, a by-product of sawmills was
found to be a promising adsorbent for the removal of PAHs present in
TPO. It is observed that adsorbents studied were comparable to those
of some conventional adsorbents.
Abstract: The paper deals with the problems of the actual
behavior, failure mechanism and load-carrying capacity of the special
bolt connection developed and intended for the assembly connections
of truss main girders of perspective railway temporary steel bridges.
Within the framework of this problem solution, several types of
structural details of assembly joints have been considered as the
conceptual structural design. Based on the preliminary evaluation of
advantages or disadvantages of these ones, in principle two basic
structural configurations – so-called “tooth” and “splice-plate”
connections have been selected for the subsequent detailed
investigation. This investigation is mainly based on the experimental
verification of the actual behavior, strain and failure mechanism and
corresponding strength of the connection, and on its numerical
modeling using FEM. This paper is focused only on the cyclic
loading (fatigue) tests results of “splice-plate” connections and their
evaluation, which have already been finished. Simultaneously with
the fatigue tests, the static loading tests have been realized too, but
these ones, as well as FEM numerical modeling, are not the subject of
this paper.
Abstract: Microbial fuel cells (MFCs) represent a promising
technology for simultaneous bioelectricity generation and wastewater
treatment. Catalysts are significant portions of the cost of microbial
fuel cell cathodes. Many materials have been tested as aqueous
cathodes, but air-cathodes are needed to avoid energy demands for
water aeration. The sluggish oxygen reduction reaction (ORR) rate at
air cathode necessitates efficient electrocatalyst such as carbon
supported platinum catalyst (Pt/C) which is very costly. Manganese
oxide (MnO2) was a representative metal oxide which has been
studied as a promising alternative electrocatalyst for ORR and has
been tested in air-cathode MFCs. However the single MnO2 has poor
electric conductivity and low stability. In the present work, the MnO2
catalyst has been modified by doping Pt nanoparticle. The goal of the
work was to improve the performance of the MFC with minimum Pt
loading. MnO2 and Pt nanoparticles were prepared by hydrothermal
and sol gel methods, respectively. Wet impregnation method was
used to synthesize Pt/MnO2 catalyst. The catalysts were further used
as cathode catalysts in air-cathode cubic MFCs, in which anaerobic
sludge was inoculated as biocatalysts and palm oil mill effluent
(POME) was used as the substrate in the anode chamber. The asprepared
Pt/MnO2 was characterized comprehensively through field
emission scanning electron microscope (FESEM), X-Ray diffraction
(XRD), X-ray photoelectron spectroscopy (XPS), and cyclic
voltammetry (CV) where its surface morphology, crystallinity,
oxidation state and electrochemical activity were examined,
respectively. XPS revealed Mn (IV) oxidation state and Pt (0)
nanoparticle metal, indicating the presence of MnO2 and Pt.
Morphology of Pt/MnO2 observed from FESEM shows that the
doping of Pt did not cause change in needle-like shape of MnO2
which provides large contacting surface area. The electrochemical
active area of the Pt/MnO2 catalysts has been increased from 276 to
617 m2/g with the increase in Pt loading from 0.2 to 0.8 wt%. The
CV results in O2 saturated neutral Na2SO4 solution showed that
MnO2 and Pt/MnO2 catalysts could catalyze ORR with different
catalytic activities. MFC with Pt/MnO2 (0.4 wt% Pt) as air cathode
catalyst generates a maximum power density of 165 mW/m3, which
is higher than that of MFC with MnO2 catalyst (95 mW/m3). The
open circuit voltage (OCV) of the MFC operated with MnO2 cathode
gradually decreased during 14 days of operation, whereas the MFC
with Pt/MnO2 cathode remained almost constant throughout the
operation suggesting the higher stability of the Pt/MnO2 catalyst.
Therefore, Pt/MnO2 with 0.4 wt% Pt successfully demonstrated as an
efficient and low cost electrocatalyst for ORR in air cathode MFC with higher electrochemical activity, stability and hence enhanced
performance.
Abstract: In this study, we have focused our attention on
combining of molecular imprinting into nanofilms and QCM
nanosensor approaches and producing QCM nanosensor for anti-
CCP, chosen as model protein, using anti-CCP imprinted nanofilms.
The nonimprinted nanosensor was also prepared to evaluate the
selectivity of the imprinted nanosensor. Anti-CCP imprinted QCM
nanosensor was tested for real time detection of anti-CCP from
aqueous solution. The kinetic and affinity studies were determined by
using anti-CCP solutions with different concentrations. The
responses related with mass shifts (%m) and frequency shifts (%f)
were used to evaluate adsorption properties. To show the selectivity
of the anti-CCP imprinted QCM nanosensor, competitive adsorption
of anti-CCP and IgM was investigated. The results indicate that anti-
CCP imprinted QCM nanosensor has higher adsorption capabilities
for anti-CCP than for IgM, due to selective cavities in the polymer
structure.
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: Examining existing experimental results for shallow
rigid foundations subjected to vertical centric load (N), accompanied
or not with a bending moment (M), two main non-linear mechanisms
governing the cyclic response of the soil-foundation system can be
distinguished: foundation uplift and soil yielding. A soil-foundation
failure limit, is defined as a domain of resistance in the two
dimensional (2D) load space (N, M) inside of which lie all the
admissible combinations of loads; these latter correspond to a pure
elastic, non-linear elastic or plastic behavior of the soil-foundation
system, while the points lying on the failure limit correspond to a
combination of loads leading to a failure of the soil-foundation
system. In this study, the proposed resistance domain is constructed
analytically based on mechanics. Original elastic limit, uplift
initiation limit and iso-uplift limits are constructed inside this
domain. These limits give a prediction of the mechanisms activated
for each combination of loads applied to the foundation. A
comparison of the proposed failure limit with experimental tests
existing in the literature shows interesting results. Also, the
developed uplift initiation limit and iso-uplift curves are confronted
with others already proposed in the literature and widely used due to
the absence of other alternatives, and remarkable differences are
noted, showing evident errors in the past proposals and relevant
accuracy for those given in the present work.
Abstract: Modular structural systems are constructed using a
method that they are assembled with prefabricated unit modular
frames on-site. This provides a benefit that can significantly reduce
building construction time. The structural design is usually carried out
under the assumption that their load-carrying mechanism is similar to
that of traditional steel moment-resisting systems. However, both
systems are different in terms of beam-column connection details
which may strongly influence the lateral structural behavior. Specially,
the presence of access holes in a beam-column joint of a unit modular
frame could cause undesirable failure during strong earthquakes.
Therefore, this study carried out finite element analyses (FEMs) of
unit modular frames to investigate the cyclic behavior of beam-column
joints with the access holes. Analysis results show that the unit
modular frames present stable cyclic response with large deformation
capacities and their joints are classified into semi-rigid connections
even if there are access holes.
Abstract: Carbon nanotube is one of the most attractive materials
for the potential applications of nanotechnology due to its excellent
mechanical, thermal, electrical and optical properties. In this paper we
report a supercapacitor made of nickel foil electrodes, coated with
multiwall carbon nanotubes (MWCNTs) thin film using
electrophoretic deposition (EPD) method. Chemical vapor deposition
method was used for the growth of MWCNTs and ethanol was used as
a hydrocarbon source. High graphitic multiwall carbon nanotube was
found at 750oC analyzing by Raman spectroscopy. We observed the
electrochemical performance of supercapacitor by cyclic
voltammetry. The electrodes of supercapacitor fabricated from
MWCNTs exhibit considerably small equivalent series resistance
(ESR), and a high specific power density. Electrophoretic deposition
is an easy method in fabricating MWCNT electrodes for high
performance supercapacitor.
Abstract: In wireless communication, space-time block code (STBC), cyclic delay diversity (CDD) and space-time cyclic delay diversity (STCDD)are used as the spatial diversity schemes and have been widely studied for the reliablecommunication. If these schemes are used, the communication system can obtain the improved performance. However,the quality of the system is degraded when the distance between a source and a destination is distant in wireless communication system. In this paper, the cooperative transmission scheme using two sources is proposed and improves the performance of the wireless communication system.
Abstract: Monocopter is a single-wing rotary flying vehicle
which has the capability of hovering. This flying vehicle includes two
dynamic parts in which more efficiency can be expected rather than
other Micro UAVs due to the extended area of wing compared to its
fuselage. Low cost and simple mechanism in comparison to other
vehicles such as helicopter are the most important specifications of
this flying vehicle.
In the previous paper we discussed the introduction of the final
system but in this paper, the experimental design process of
Monocopter and its control algorithm has been investigated in
general. Also the editorial bugs in the previous article have been
corrected and some translational ambiguities have been resolved.
Initially by constructing several prototypes and carrying out many
flight tests the main design parameters of this air vehicle were
obtained by experimental measurements. Eventually the required
main monocopter for this project was constructed. After construction
of the monocopter in order to design, implementation and testing of
control algorithms first a simple optic system used for determining
the heading angle. After doing numerous tests on Test Stand, the
control algorithm designed and timing of applying control inputs
adjusted. Then other control parameters of system were tuned in
flight tests. Eventually the final control system designed and
implemented using the AHRS sensor and the final operational tests
performed successfully.
Abstract: Precast residential houses are normally constructed in Malaysia using precast shear-key wall panel and this panel is designed using BS8110 where there is no provision for earthquake. However, the safety of this house under moderate and strong earthquake is still questionable. Consequently, the full-scale of residential house are designed, constructed, tested and analyzed under in-plane lateral quasi-static cyclic loading. Hysteresis loops are plotted based on the experimental work and compared with modeling of hysteresis loops using HYSTERES in RUAUMOKO 2D program. Modified Takeda hysteresis model is chosen to behave a similar pattern with experimental work. This program will display the earthquake excitations, spectral displacements, pseudo spectral acceleration, mode shape and deformation of the structure. It can be concluded that this building is suffering severe cracks and damage under moderate and severe earthquake.
Abstract: The substantial similarity of fatigue mechanism in a
new test rig for rolling contact fatigue (RCF) has been investigated. A
new reduced-scale test rig is designed to perform controlled RCF
tests in wheel-rail materials. The fatigue mechanism of the rig is
evaluated in this study using a combined finite element-fatigue
prediction approach. The influences of loading conditions on fatigue
crack initiation have been studied. Furthermore, the effects of some
artificial defects (squat-shape) on fatigue lives are examined. To
simulate the vehicle-track interaction by means of the test rig, a threedimensional
finite element (FE) model is built up. The nonlinear
material behaviour of the rail steel is modelled in the contact
interface. The results of FE simulations are combined with the critical
plane concept to determine the material points with the greatest
possibility of fatigue failure. Based on the stress-strain responses, by
employing of previously postulated criteria for fatigue crack initiation
(plastic shakedown and ratchetting), fatigue life analysis is carried
out. The results are reported for various loading conditions and
different defect sizes. Afterward, the cyclic mechanism of the test rig
is evaluated from the operational viewpoint. The results of fatigue
life predictions are compared with the expected number of cycles of
the test rig by its cyclic nature. Finally, the estimative duration of the
experiments until fatigue crack initiation is roughly determined.
Abstract: This paper present the experimental work of double
unit tunnel form building (TFB) subjected to in-plane lateral cyclic
loading. A one third scale of 3-storey double unit of TFB is tested
until its strength degradation. Then, the TFB is repaired and
retrofitted using additional shear wall, steel angle and CFRP sheet.
The crack patterns, lateral strength, stiffness, ductility and equivalent
viscous damping (EVD) were analyzed and compared before and
after repair and retrofit. The result indicates that the lateral strength
increases by 22% in pushing and 27% in pulling direction. Moreover,
the stiffness and ductility obtained before and after retrofit increase
tremendously by 87.87% and 39.66%, respectively. Meanwhile, the
energy absorption measured by equivalent viscous damping obtained
after retrofit increase by 12.34% in pulling direction. It can be
concluded that the proposed retrofit method is capable to increase the
lateral strength capacity, stiffness and energy absorption of double
unit TFB.
Abstract: This study investigates the effect of moisture
conditioning on the Indirect Tensile Strength (ITS) of asphalt
concrete. As a first step, cylindrical samples of 100 mm diameter and
50 mm thick were prepared using a Superpave gyratory compactor.
Next, the samples were conditioned using Moisture Induced
Susceptibility Test (MIST) device at different numbers of moisture
conditioning cycles. In the MIST device, samples are subjected water
pressure through the sample pores cyclically. The MIST conditioned
samples were tested for ITS. Results show that the ITS does not
change significantly with MIST conditioning at the specific pressure
and cycles adopted in this study.
Abstract: In this study, we developed a complementary electrochromic device consisting of WO3 and NiO films fabricated by rf-magnetron sputtered. The electrochromic properties of WO3 and NiO films were investigated using cyclic voltammograms (CV), performed on WO3 and NiO films immersed in an electrolyte of 1 M LiClO4 in propylene carbonate (PC). Optical and electrochemical of the films, as a function of coloration–bleaching cycle, were characterized using an UV-Vis-NIR spectrophotometer and cyclic voltammetry (CV). After investigating the properties of WO3 film, NiO film, and complementary electrochromic devices, we concluded that this device provides good reversibility, low power consumption of -2.5 V in color state, high variation of transmittance of 58.96%, changes in optical density of 0.81 and good memory effect under open-circuit conditions. In addition, electrochromic component penetration rate can be retained below 20% within 24h, showing preferred memory features; however, component coloring and bleaching response time are about 33s.
Abstract: Diverse contaminants released into the environment through progress of urbanization and industrialization adversely affect human health. Among various sources of contaminants, especially, in big cities, automobiles play a significant role in aggravating the pollution. Various pollutants viz., heavy metals (Pb, Mn, Ni, Zn, As, Hg, Cd) and Polyaromatic hydrocarbons (Benzo-a-pyrene, fluoranthene, pyrene, benzo-b-anthracene, benzo-b-fluoranthene, acenaphthylene, fluorine, phenantherene, anthracene, chrysene, benzo-k-fluoranthene, benzo-e-pyrene, indenol-1,2,3-cd-pyrene, dibenzo-a,h-anthracene, benzo-ghi-perylene) are released by vehicles. Further, these pollutants are expected to cause severe mutagenic, genotoxic and carcinogenic effects. Considering this, many authors monitored the levels of pollution in roadside soil, water and plants. The present review focuses upon the analysis and effects of heavy metals and polycyclic aromatic hydrocarbons from the roadside samples.