Abstract: Among the technologies available to reduce methane
emitted from the pig industry, biofiltration seems to be an effective
and inexpensive solution. In methane (CH4) biofiltration, nitrogen is
an important macronutrient for the microorganisms growth. The
objective of this research project was to study the effect of
ammonium (NH4
+) on the performance, the biomass production and
the nitrogen conversion of a biofilter treating methane. For NH4
+
concentrations ranging from 0.05 to 0.5 gN-NH4
+/L, the CH4 removal
efficiency and the dioxide carbon production rate decreased linearly
from 68 to 11.8 % and from 7.1 to 0.5 g/(m3-h), respectively. The dry
biomass content varied from 4.1 to 5.8 kg/(m3 filter bed). For the
same range of concentrations, the ammonium conversion decreased
while the specific nitrate production rate increased. The specific
nitrate production rate presented negative values indicating
denitrification in the biofilter.
Abstract: The ability to predict an accurate temperature
distribution requires the knowledge of the losses, the thermal
characteristics of the materials, and the cooling conditions, all of
which are very difficult to quantify. In this paper, the impact of the
effects of iron and copper losses are investigated separately and
their effects on the heating in various points of the stator of an
induction motor, is highlighted by using two simple tests. In addition,
the effect of a defect, such as an open circuit in a phase of the stator,
on the heating is also obtained by a no-load test.
The squirrel cage induction motor is rated at 2.2 kW; 380 V; 5.2
A; Δ connected; 50 Hz; 1420 rpm and the class of insulation F, has
been thermally tested under several load conditions. Several
thermocouples were placed in strategic points of the stator.
Abstract: A higher order spline interpolated contour obtained
with up-sampling of homogenously distributed coordinates for
segmentation of kidney region in different classes of ultrasound
kidney images has been developed and presented in this paper. The
performance of the proposed method is measured and compared with
modified snake model contour, Markov random field contour and
expert outlined contour. The validation of the method is made in
correspondence with expert outlined contour using maximum coordinate
distance, Hausdorff distance and mean radial distance
metrics. The results obtained reveal that proposed scheme provides
optimum contour that agrees well with expert outlined contour.
Moreover this technique helps to preserve the pixels-of-interest
which in specific defines the functional characteristic of kidney. This
explores various possibilities in implementing computer-aided
diagnosis system exclusively for US kidney images.
Abstract: In this study the integration of an absorption heat
pump (AHP) with the concentration section of an industrial pulp and
paper process is investigated using pinch technology. The optimum
design of the proposed water-lithium bromide AHP is then achieved
by minimizing the total annual cost. A comprehensive optimization is
carried out by relaxation of all stream pressure drops as well as heat
exchanger areas involving in AHP structure. It is shown that by
applying genetic algorithm optimizer, the total annual cost of the
proposed AHP is decreased by 18% compared to one resulted from
simulation.
Abstract: Lateral expansion is a factor defining the level of
confinement in reinforced concrete columns. Therefore, predicting
the lateral strain relationship with axial strain becomes an important
issue. Measuring lateral strains in experiments is difficult and only
few report experimental lateral strains. Among the existing analytical
formulations, two recent models are compared with available test
results in this paper with shortcomings highlighted. A new analytical
model is proposed here for lateral strain axial strain relationship and
is based on the supposition that the concrete behaves linear elastic in
the early stages of loading and then nonlinear hardening up to the
peak stress and then volumetric expansion. The proposal for the
lateral strain axial strain relationship after the peak stress is mainly
based on the hypothesis that the plastic lateral strain varies linearly
with the plastic axial strain and it is shown that this is related to the
lateral confinement level.
Abstract: This paper presents a perturbation based search method
to solve the unconstrained binary quadratic programming problem.
The proposed algorithm was tested with some of the standard test
problems and the results are reported for 10 instances of 50, 100, 250,
& 500 variable problems. A comparison of the performance of the
proposed algorithm with other heuristics and optimization software is
made. Based on the results, it was found that the proposed algorithm
is computationally inexpensive and the solutions obtained match the
best known solutions for smaller sized problems. For larger instances,
the algorithm is capable of finding a solution within 0.11% of the
best known solution. Apart from being used as a stand-alone method,
this algorithm could also be incorporated with other heuristics to find
better solutions.
Abstract: In this paper a deterministic polynomial-time
algorithm is presented for the Clique problem. The case is considered
as the problem of omitting the minimum number of vertices from the
input graph so that none of the zeroes on the graph-s adjacency
matrix (except the main diagonal entries) would remain on the
adjacency matrix of the resulting subgraph. The existence of a
deterministic polynomial-time algorithm for the Clique problem, as
an NP-complete problem will prove the equality of P and NP
complexity classes.
Abstract: Question answering (QA) aims at retrieving precise information from a large collection of documents. Most of the Question Answering systems composed of three main modules: question processing, document processing and answer processing. Question processing module plays an important role in QA systems to reformulate questions. Moreover answer processing module is an emerging topic in QA systems, where these systems are often required to rank and validate candidate answers. These techniques aiming at finding short and precise answers are often based on the semantic relations and co-occurrence keywords. This paper discussed about a new model for question answering which improved two main modules, question processing and answer processing which both affect on the evaluation of the system operations. There are two important components which are the bases of the question processing. First component is question classification that specifies types of question and answer. Second one is reformulation which converts the user's question into an understandable question by QA system in a specific domain. The objective of an Answer Validation task is thus to judge the correctness of an answer returned by a QA system, according to the text snippet given to support it. For validating answers we apply candidate answer filtering, candidate answer ranking and also it has a final validation section by user voting. Also this paper described new architecture of question and answer processing modules with modeling, implementing and evaluating the system. The system differs from most question answering systems in its answer validation model. This module makes it more suitable to find exact answer. Results show that, from total 50 asked questions, evaluation of the model, show 92% improving the decision of the system.
Abstract: The chatter is one of the major limitations of the productivity in the ball end milling process. It affects the surface roughness, the dimensional accuracy and the tool life. The aim of this research is to propose the new system to detect the chatter during the ball end milling process by using the wavelet transform. The proposed method is implemented on the 5-axis CNC machining center and the new three parameters are introduced from three dynamic cutting forces, which are calculated by taking the ratio of the average variances of dynamic cutting forces to the absolute variances of themselves. It had been proved that the chatter can be easier to detect during the in-process cutting by using the new parameters which are proposed in this research. The experimentally obtained results showed that the wavelet transform can provide the reliable results to detect the chatter under various cutting conditions.
Abstract: In this research, the main aim is to investigate the
antimicrobial effectiveness of ammonyx solutions finishing on
Sweatshirt Sport with immersion method. 60 Male healthy subjects
(football player) participated in this study. They were dressed in a
Sweatshirt for 14 days and some microbes found on them were
investigated. The antimicrobial effect of different ammonyx
solutions(1/100, 1/500, 1/1000, 1/2000 v/v solutions of Ammonyx)
on the identified microbes was studied by the zone inhabitation
method in vitro. In the next step the Sweatshirt Sports were treated
with the same different solutions of ammonyx and the antimicrobial
effectiveness was assessed by colony count method in different times
and the results were compared whit untreated ones. Some mechanical
properties of treated cotton/polyester yarn that used in Sweatshirt
Sport were measured after 30 days and were compared with
untreated one. Finally after finishing, scanning electron microscopy
(SEM) was used to compare the surfaces of the finished and
unfinished specimens. The results showed the presence of five
pathogenic microbes on Sweatshirt Sports such as Escherichia coli,
Staphylococcus aureus, Aspergillus, Mucor and Candida. The
inhalation time for treated on Sweatshirt Sports improved. The
amount of colony growth on treated clothes reduced considerably
and moreover the mechanical tests results showed no significant
deterioration effect of studies properties in comparison to the
untreated yarn. The visual examination of the SEM indicated that the
antimicrobial treatments were applied usefully to fabrics.
Abstract: Given a bivariate normal sample of correlated variables,
(Xi, Yi), i = 1, . . . , n, an alternative estimator of Pearson’s correlation
coefficient is obtained in terms of the ranges, |Xi − Yi|.
An approximate confidence interval for ρX,Y is then derived, and
a simulation study reveals that the resulting coverage probabilities
are in close agreement with the set confidence levels. As well, a
new approximant is provided for the density function of R, the
sample correlation coefficient. A mixture involving the proposed
approximate density of R, denoted by hR(r), and a density function
determined from a known approximation due to R. A. Fisher is shown
to accurately approximate the distribution of R. Finally, nearly exact
density approximants are obtained on adjusting hR(r) by a 7th degree
polynomial.
Abstract: In this paper an alternative analysis in the time
domain is described and the results of the interpolation process are
presented by means of functions that are based on the rule of
conditional mathematical expectation and the covariance function. A
comparison between the interpolation error caused by low order
filters and the classic sinc(t) truncated function is also presented.
When fewer samples are used, low-order filters have less error. If the
number of samples increases, the sinc(t) type functions are a better
alternative. Generally speaking there is an optimal filter for each
input signal which depends on the filter length and covariance
function of the signal. A novel scheme of work for adaptive
interpolation filters is also presented.
Abstract: In this paper three basic approaches and different
methods under each of them for extracting region of interest (ROI)
from stationary images are explored. The results obtained for each of
the proposed methods are shown, and it is demonstrated where each
method outperforms the other. Two main problems in ROI
extraction: the channel selection problem and the saliency reversal
problem are discussed and how best these two are addressed by
various methods is also seen. The basic approaches are 1) Saliency
based approach 2) Wavelet based approach 3) Clustering based
approach. The saliency approach performs well on images containing
objects of high saturation and brightness. The wavelet based
approach performs well on natural scene images that contain regions
of distinct textures. The mean shift clustering approach partitions the
image into regions according to the density distribution of pixel
intensities. The experimental results of various methodologies show
that each technique performs at different acceptable levels for
various types of images.
Abstract: the paper presents the optimization results for several
electrical machines dedicated for powered electric wheel-chairs. The
optimization, using the Hook-Jeeves algorithm, was employed based
on a design approach which takes into consideration the road
conditions. Also, through numerical simulations (based on finite
element method), the analytical approach was validated. The
optimization approach gave satisfactory results and the best suited
variant was chosen for the motorization of the wheel-chair.
Abstract: In this article, we synthesize a novel chitosan -based
superabsorbent hydrogel via graft copolymerization of mixtures
acrylic acid (AA) and N-vinyl pyrollidon onto chitosan backbones.
The polymerization reaction was carried out in an aqueous medium
and in the presence of ammonium persulfate (APS) as an initiator and
N,N'-methylene bisacrylamide (MBA) as a crosslinker.The hydrogel
structures were confirmed by FTIR spectroscopy. The swelling
behavior of these absorbent polymers was also investigated in
various salt solutions. Results indicated that the swelling capacity
decreased with an increase in the ionic strength of the swelling
medium. Furthermore, the swelling of superabsorbing hydrogels was
examined in solutions with pH values ranging between 1.0 and 13.0.
It showed a reversible pH-responsive behavior at pHs 2.0 and 8.0.
This on-off switching behavior makes the synthesized hydrogels as
an excellent candidate for controlled delivery of bioactive agents.
Abstract: In this paper, the application of thermal spray
coatings in high speed shafts by a revolution up to 23000 RPM
has been studied. Gas compressor shafts are worn in contact
zone with journal therefore will be undersized. Wear
mechanisms of compressor shaft were identified. The
predominant wear mechanism is abrasion wear. The worn
surface was coated by hard WC-Co cermets using high
velocity oxy fuel (HVOF) after preparation. The shafts were in
satisfactory service in 8000h period. The metallurgical and
Tribological studies has been made on the worn and coated
shaft using optical microscopy, scanning electron microscopy
(SEM) and X-ray diffraction.
Abstract: This paper presents an economic game for sybil
detection in a distributed computing environment. Cost parameters
reflecting impacts of different sybil attacks are introduced in the sybil
detection game. The optimal strategies for this game in which both
sybil and non-sybil identities are expected to participate are devised.
A cost sharing economic mechanism called Discriminatory
Rewarding Mechanism for Sybil Detection is proposed based on this
game. A detective accepts a security deposit from each active agent,
negotiates with the agents and offers rewards to the sybils if the latter
disclose their identity. The basic objective of the detective is to
determine the optimum reward amount for each sybil which will
encourage the maximum possible number of sybils to reveal
themselves. Maintaining privacy is an important issue for the
mechanism since the participants involved in the negotiation are
generally reluctant to share their private information. The mechanism
has been applied to Tor by introducing a reputation scoring function.
Abstract: Stable bacterial polymorphism on a single limiting resource may appear if between the evolved strains metabolic interactions take place that allow the exchange of essential nutrients [8]. Towards an attempt to predict the possible outcome of longrunning evolution experiments, a network based on the metabolic capabilities of homogeneous populations of every single gene knockout strain (nodes) of the bacterium E. coli is reconstructed. Potential metabolic interactions (edges) are allowed only between strains of different metabolic capabilities. Bacterial communities are determined by finding cliques in this network. Growth of the emerged hypothetical bacterial communities is simulated by extending the metabolic flux balance analysis model of Varma et al [2] to embody heterogeneous cell population growth in a mutual environment. Results from aerobic growth on 10 different carbon sources are presented. The upper bounds of the diversity that can emerge from single-cloned populations of E. coli such as the number of strains that appears to metabolically differ from most strains (highly connected nodes), the maximum clique size as well as the number of all the possible communities are determined. Certain single gene deletions are identified to consistently participate in our hypothetical bacterial communities under most environmental conditions implying a pattern of growth-condition- invariant strains with similar metabolic effects. Moreover, evaluation of all the hypothetical bacterial communities under growth on pyruvate reveals heterogeneous populations that can exhibit superior growth performance when compared to the performance of the homogeneous wild-type population.
Abstract: Pressure waves and Water Hammer occur in a
pumping system when valves are closed or opened suddenly or in
the case of sudden failure of pumps. Determination of maximum
water hammer is considered one of the most important technical
and economical items of which engineers and designers of
pumping stations and conveyance pipelines should take care.
Hammer Software is a recent application used to simulate water
hammer. The present study focuses on determining significance of
each input parameter of the application relative to the maximum
amount of water hammer estimated by the software. The study
determines estimated maximum water hammer variations due to
variations of input parameters including water temperature, pipe
type, thickness and diameter, electromotor rpm and power, and
moment of inertia of electromotor and pump. In our study,
Kuhrang Pumping Station was modeled using WaterGEMS
Software. The pumping station is characterized by total discharge
of 200 liters per second, dynamic height of 194 meters and 1.5
kilometers of steel conveyance pipeline and transports water to
Cheshme Morvarid for farmland irrigation. The model was run in
steady hydraulic condition and transferred to Hammer Software.
Then, the model was run in several unsteady hydraulic conditions
and sensitivity of maximum water hammer to each input parameter
was calculated. It is shown that parameters to which maximum
water hammer is most sensitive are moment of inertia of pump and
electromotor, diameter, type and thickness of pipe and water
temperature, respectively.
Abstract: In Croatia, the majority of cultured marine fish species are reared in net cages. The intensive production of the fish in net cages may generate the considerable amount of bio waste and change water quality especially in enclosed and semi-enclosed coastal areas. The aim of this paper is to assess the potential impact of sea bass (Dicentrarchus labrax L.) cage farm on water quality. The weak relationship between food supply and water quality parameters (nutrient content and phytoplankton biomass) was found, but significant changes in oxygen saturation was observed in the cages during the warmer period of a year especially in the morning (occasionally it dropped below 70 %). Despite of, satisfactory results of water quality parameters, it is necessary to establish comprehensive monitoring process, especially to include quality assessment of fouling communities.