Abstract: The efficiency of the actuation system of exoskeletons
and active orthoses for lower limbs is a significant aspect of the
design of such devices because it affects their efficacy. The F-IVT is
an innovative actuation system to power artificial knee joint with
energy recovery capabilities. Its key and non-conventional elements
are a flywheel that acts as a mechanical energy storage system, and
an Infinitely Variable Transmission (IVT). The design of the F-IVT
can be optimized for a certain walking condition, resulting in a heavy
reduction of both the electric energy consumption and of the electric
peak power. In this work, by means of simulations of level ground
walking at different speeds, it is demonstrated that the F-IVT is still
an advantageous actuator which permits to save energy consumption
and to downsize the electric motor even when it does not work in
nominal conditions.
Abstract: This study is about the structural transformations of
aluminium examining with the Dynamic Mechanical Thermal
Analyzer (DMTA). It is a faster and simpler measuring method to
make consequence about the metal’s structural transformations. The
device measures the changing of the mechanical characteristics
depending on the heating rate, and concludes certain transformations.
This measuring method fast and shows clean-cut results comparing
the conventional ways.
Applying polymer measuring devices for metal investigations is
not widespread method. One of the adaptable ways is shown in this
study. The article compares the results of the small specimen test and
the DMTA method, considering the temperature and the forming
dependence of recrystallization temperature.
Abstract: Grid is an environment with millions of resources
which are dynamic and heterogeneous in nature. A computational
grid is one in which the resources are computing nodes and is meant
for applications that involves larger computations. A scheduling
algorithm is said to be efficient if and only if it performs better
resource allocation even in case of resource failure. Resource
allocation is a tedious issue since it has to consider several
requirements such as system load, processing cost and time, user’s
deadline and resource failure. This work attempts in designing a
resource allocation algorithm which is cost-effective and also targets
at load balancing, fault tolerance and user satisfaction by considering
the above requirements. The proposed Budget Constrained Load
Balancing Fault Tolerant algorithm with user satisfaction (BLBFT)
reduces the schedule makespan, schedule cost and task failure rate
and improves resource utilization. Evaluation of the proposed
BLBFT algorithm is done using Gridsim toolkit and the results are
compared with the algorithms which separately concentrates on all
these factors. The comparison results ensure that the proposed
algorithm works better than its counterparts.
Abstract: The effects of the pumping wavelength and their power
on the gain flattening of a fiber Raman amplifier (FRA) are
investigated. The multi-wavelength pumping scheme is utilized to
achieve gain flatness in FRA. It is proposed that gain flatness
becomes better with increase in number of pumping wavelengths
applied. We have achieved flat gain with 0.27 dB fluctuation in a
spectral range of 1475-1600 nm for a Raman fiber length of 10 km by
using six pumps with wavelengths with in the 1385-1495 nm interval.
The effect of multi-wavelength pumping scheme on gain saturation in
FRA is also studied. It is proposed that gain saturation condition gets
improved by using this scheme and this scheme is more useful for
higher spans of Raman fiber length.
Abstract: Coal fly ash is formed as a solid waste product from
the combustion of coal in coal fired power stations. Huge amounts of
fly ash are produced globally every year and are predicted to
increase. Nowadays, less than half of the fly ash is used as a raw
material for cement manufacturing, construction and the rest of it is
disposed as a waste causing yet another environmental concern. For
this reason, the recycling of this kind of slurries into useful materials
is quite important in terms of economical and environmental aspects.
The purpose of this study is to evaluate the Orhaneli and
Tuncbilek coal fly ashes for utilization in some industrial
applications. Therefore the mineralogical and chemical compositions
of these fly ashes were analyzed by X-ray fluorescence spectroscopy,
ourier-transform infrared spectrometer, and X-ray diffraction. The
silicon (Si) and aluminum (Al) in the fly ashes were activated by
alkali fusion technique with sodium hydroxide. The obtained extracts
were analyzed for Si and Al content by inductively coupled plasma
optical emission spectrometry.
Abstract: In this study, out-of-plane free vibrations of a circular
rods is investigated theoretically. The governing equations for
naturally twisted and curved spatial rods are obtained using
Timoshenko beam theory and rewritten for circular rods. Effects of
the axial and shear deformations are considered in the formulations.
Ordinary differential equations in scalar form are solved analytically
by using transfer matrix method. The circular rods of the mass matrix
are obtained by using straight rod of consistent mass matrix. Free
vibrations frequencies obtained by solving eigenvalue problem. A
computer program coded in MATHEMATICA language is prepared.
Circular beams are analyzed through various examples for free
vibrations analysis. Results are compared with ANSYS results based
on finite element method and available in the literature.
Abstract: Chrome tannery wastewater causes serious environmental hazard due to its high pollution potential. As a result, rigorous treatment is necessary for abatement of pollution from this type of wastewater. There are many research studies on chrome tannery wastewater treatment in the field of physical, chemical, and biological methods. In general, biological treatment process is found ineffective for direct application because of adverse effects by toxic chromium, sulphide, chloride etc. However, biological methods were employed mainly for a few sub processes generating significant amount of organic matter and without chromium, chlorides etc. In this context the present paper reviews the characteristics feature and pollution potential of wastewater generated from chrome tannery units and treatment of the same. The different biological processes used earlier and their chronological development for treatment of the chrome tannery wastewater are thoroughly reviewed in this paper. In this regard, the scope of hybrid bioreactor - an advanced technology option has also been explored, as this kind of treatment is well suited for the wastewater having inhibitory substances.
Abstract: Introduction: Researchers globally have strived to explore diverse factors that augment the continuation and uptake of family planning methods. Clients’ satisfaction is one of the core determinants facilitating continuation of family planning methods. There is a major debate yet scanty evidence to contrast public and private sectors with respect to client satisfaction. The objective of this study is to compare quality-of-care provided by public and private sectors of Pakistan through a client satisfaction lens. Methods: We used Pakistan Demographic Heath Survey 2012-13 dataset on 3133 women. Ten different multivariate models were made. to explore the relationship between client satisfaction and dependent outcome after adjusting for all known confounding factors and results are presented as OR and AOR (95% CI). Results: Multivariate analyses showed that clients were less satisfied in contraceptive provision from private sector as compared to public sector (AOR 0.92, 95% CI 0.63-1.68) even though the result was not statistically significant. Clients were more satisfied from private sector as compared to the public sector with respect to other determinants of quality-of-care follow-up care (AOR 3.29, 95% CI 1.95-5.55), infection prevention (AOR 2.41, 95% CI 1.60-3.62), counseling services (AOR 2.01, 95% CI 1.27-3.18, timely treatment (AOR 3.37, 95% CI 2.20-5.15), attitude of staff (AOR 2.23, 95% CI 1.50-3.33), punctuality of staff (AOR 2.28, 95% CI 1.92-4.13), timely referring (AOR 2.34, 95% CI 1.63-3.35), staff cooperation (AOR 1.75, 95% CI 1.22-2.51) and complications handling (AOR 2.27, 95% CI 1.56-3.29). Discussion: Public sector has successfully attained substantial satisfaction levels with respect to provision of contraceptives, but it contrasts previous literature from a multi country studies. Our study though in is concordance with a study from Tanzania where public sector was more likely to offer family planning services to clients as compared to private facilities. Conclusion: In majority of the developing countries, public sector is more involved in FP service provision; however, in Pakistan clients’ satisfaction in private sector is more, which opens doors for public-private partnerships and collaboration in the near future.
Abstract: Wavelength Division Multiplexing (WDM) is the dominant transport technology used in numerous high capacity backbone networks, based on optical infrastructures. Given the importance of costs (CapEx and OpEx) associated to these networks, resource management is becoming increasingly important, especially how the optical circuits, called “lightpaths”, are routed throughout the network. This requires the use of efficient algorithms which provide routing strategies with the lowest cost. We focus on the lightpath routing and wavelength assignment problem, known as the RWA problem, while optimizing wavelength fragmentation over the network. Wavelength fragmentation poses a serious challenge for network operators since it leads to the misuse of the wavelength spectrum, and then to the refusal of new lightpath requests. In this paper, we first establish a new Integer Linear Program (ILP) for the problem based on a node-link formulation. This formulation is based on a multilayer approach where the original network is decomposed into several network layers, each corresponding to a wavelength. Furthermore, we propose an efficient heuristic for the problem based on a greedy algorithm followed by a post-treatment procedure. The obtained results show that the optimal solution is often reached. We also compare our results with those of other RWA heuristic methods
Abstract: In this contribution a structure for high level lateral vehicle tracking control based on the disturbance observer is presented. The structure is characterized by stationary compensating side forces disturbances and guaranteeing a cooperative behavior at the same time. Driver inputs are not compensated by the disturbance observer. Moreover the structure is especially useful as it robustly stabilizes the vehicle. Therefore the parameters are selected using the Parameter Space Approach. The implemented algorithms are tested in real world scenarios.
Abstract: Steel tubular towers serving as support structures for large wind turbines are subjected to several hundred million stress cycles caused by the turbulent nature of the wind. This causes highcycle fatigue, which could govern the design of the tower. Maintaining the support structure after the wind turbines reach its typical 20-year design life has become a common practice; however, quantifying the changes in the reliability on the tower is not usual. In this paper the effect of fatigue damage in the wind turbine structure is studied whit the use of fracture mechanics, and a method to estimate the reliability over time of the structure is proposed. A representative wind turbine located in Oaxaca, Mexico is then studied. It is found that the system reliability is significantly affected by the accumulation of fatigue damage.
Abstract: A reliability-based methodology which uses structural demand hazard curves to consider the increment of the ductility demands of structures with tilting is proposed. The approach considers the effect of two orthogonal components of the ground motions as well as the influence of soil-structure interaction. The approach involves the calculation of ductility demand hazard curves for symmetric systems and, alternatively, for systems with different degrees of asymmetry. To get this objective, demand hazard curves corresponding to different global ductility demands of the systems are calculated. Next, Uniform Exceedance Rate Spectra (UERS) are developed for a specific mean annual rate of exceedance value. Ratios between UERS corresponding to asymmetric and to symmetric systems located in soft soil of the valley of Mexico are obtained. Results indicate that the ductility demands corresponding to tilted structures may be several times higher than those corresponding to symmetric structures, depending on several factors such as tilting angle and vibration period of structure and soil.
Abstract: The study discussed in this paper was conducted in an
attempt to investigate effects of different drying methods (line dry
and tumble dry) on viscose single jersey fabrics knitted with ring
yarn.
Abstract: Investigations on the accumulation of heavy metals in
water and sediments of river Ogbese were carried out between
December 2010 and February 2011 using Atomic Absorption
Spectrophotometer. Etheria elliptica a sessile organism was also used
to determine the concentration of heavy metal in the aquatic
environmental. In water, Cu had the highest concentration (0.55 –
0.13 mg/l ±0.1) while in sediments, the highest value obtained was in
Fe (1.46-3.89mg/l±0.27). The minimum concentrations recorded
were in Pb; which was below detectable level. The result also
revealed that the shell accumulate more heavy metals than the flesh
of the mussel with Cu in the shell exhibiting a negative correlation
with all the metals in the flesh. However, the condition factor (K)
value is 6.44, an indication of good health. The length-weight
relationship is expressed as W = -0.48 x L 1.94 (r2 = 0.29) showing the
growth pattern to be negatively allometric.
Abstract: The present work attempts to investigate the
combustion, performance and emission characteristics of an existing
single-cylinder four-stroke compression-ignition engine operated in
dual-fuel mode with hydrogen as an alternative fuel. Environmental
concerns and limited amount of petroleum fuels have caused interests
in the development of alternative fuels like hydrogen for internal
combustion (IC) engines. In this experimental investigation, a diesel
engine is made to run using hydrogen in dual fuel mode with diesel,
where hydrogen is introduced into the intake manifold using an LPGCNG
injector and pilot diesel is injected using diesel injectors. A
Timed Manifold Injection (TMI) system has been developed to vary
the injection strategies. The optimized timing for the injection of
hydrogen was 10^0 CA after top dead center (ATDC). From the study
it was observed that with increasing hydrogen rate, enhancement in
brake thermal efficiency (BTHE) of the engine has been observed
with reduction in brake specific energy consumption (BSEC).
Furthermore, Soot contents decrease with an increase in indicated
specific NOx emissions with the enhancement of hydrogen flow rate.
Abstract: The thermal performance of a solar water heating with
1.00 m2 flat plate collectors in Cascavel - PR, is which presented in
this article, paper presents the solution to leverage the marketing of
solar heating systems through detailed constituent materials of the
solar collector studies, these abundant materials in construction, such
as expanded polyethylene, PVC, aluminum and glass tubes, mixing
them with new materials to minimize loss of efficiency while
decreasing its cost. The system was tested during months and the
collector obtained maximum recorded temperature of outlet fluid of
55°C, while the maximum temperature of the water at the bottom of
the hot water tank was 35°C. The average daily energy collected was
19.6 MJ/d; the energy supplied by the solar plate was 16.2 MJ/d; the
loss in the feed pipe was 3.2 MJ/d; the solar fraction was 32.2%, the
efficiency of the collector was 45.6% and the efficiency of the system
was 37.8%.
Abstract: Scrubbing by a liquid spraying is one of the most
effective processes used for removal of fine particles and soluble
gas pollutants (such as SO2, HCl, HF) from the flue gas. There are
many configurations of scrubbers designed to provide contact
between the liquid and gas stream for effectively capturing
particles or soluble gas pollutants, such as spray plates, packed bed
towers, jet scrubbers, cyclones, vortex and venturi scrubbers. The
primary function of venturi scrubber is the capture of fine particles
as well as HCl, HF or SO2 removal with effect of the flue gas
temperature decrease before input to the absorption column. In this
paper, sulfur dioxide (SO2) from flue gas was captured using new
design replacing venturi scrubber (1st degree of wet scrubbing).
The flue gas was prepared by the combustion of the carbon
disulfide solution in toluene (1:1 vol.) in the flame in the reactor.
Such prepared flue gas with temperature around 150°C was
processed in designed laboratory O-element scrubber. Water was
used as absorbent liquid. The efficiency of SO2 removal, pressure
drop and temperature drop were measured on our experimental
device. The dependence of these variables on liquid-gas ratio was
observed. The average temperature drop was in the range from
150°C to 40°C. The pressure drop was increased with increasing of
a liquid-gas ratio, but no too much as for the common venturi
scrubber designs. The efficiency of SO2 removal was up to 70 %.
The pressure drop of our new designed wet scrubber is similar to
commonly used venturi scrubbers; nevertheless the influence of
amount of the liquid on pressure drop is not so significant.
Abstract: Moving into a new era of healthcare, new tools and
devices are developed to extend and improve health services, such as
remote patient monitoring and risk prevention. In this concept,
Internet of Things (IoT) and Cloud Computing present great
advantages by providing remote and efficient services, as well as
cooperation between patients, clinicians, researchers and other health
professionals. This paper focuses on patients suffering from bipolar
disorder, a brain disorder that belongs to a group of conditions
called affective disorders, which is characterized by great mood
swings. We exploit the advantages of Semantic Web and Cloud
Technologies to develop a patient monitoring system to support
clinicians. Based on intelligently filtering of evidence-knowledge and
individual-specific information we aim to provide treatment
notifications and recommended function tests at appropriate times or
concluding into alerts for serious mood changes and patient’s nonresponse
to treatment. We propose an architecture as the back-end
part of a cloud platform for IoT, intertwining intelligence devices
with patients’ daily routine and clinicians’ support.
Abstract: We investigate relaxation dynamics of a quantum
dipole emitter (QDE), e.g., a molecule or quantum dot, located near a
metal nanoparticle (MNP) exhibiting a dipolar localized surface
plasmon (LSP) resonance at the frequency of the QDE radiative
transition. It is shown that under the condition of the QDE-MNP
characteristic relaxation time being much shorter than that of the
QDE in free-space but much longer than the LSP lifetime. It is also
shown that energy dissipation in the QDE-MNP system is relatively
weak with the probability of the photon emission being about 0.75, a
number which, rather surprisingly, does not explicitly depend on the
metal absorption characteristics. The degree of entanglement
measured by the concurrency takes the maximum value, while the
distances between the QDEs and metal ball approximately are equal.
Abstract: Propylene self-metathesis to ethylene and butene was
studied over WOx/SiO2 catalysts at 450oC and atmospheric pressure.
The WOx/SiO2 catalysts were prepared by incipient wetness
impregnation of ammonium metatungstate aqueous solution. It was
found that, adding nano-sized extra supports (SiO2 and TiO2) by
physical mixing with the WOx/SiO2 enhanced propylene conversion.
The UV-Vis and FT-Raman results revealed that WOx could migrate
from the original silica support to the extra support, leading to a
better dispersion of WOx. The ICP-OES results also indicate that
WOx existed on the extra support. Coke formation was investigated
on the catalysts after 10 h time-on-stream by TPO. However, adding
nano-sized extra supports led to higher coke formation which may be
related to acidity as characterized by NH3-TPD.