Abstract: Horizontal wells are proven to be better producers
because they can be extended for a long distance in the pay zone.
Engineers have the technical means to forecast the well productivity
for a given horizontal length. However, experiences have shown that
the actual production rate is often significantly less than that of
forecasted. It is a difficult task, if not impossible to identify the real
reason why a horizontal well is not producing what was forecasted.
Often the source of problem lies in the drilling of horizontal section
such as permeability reduction in the pay zone due to mud invasion
or snaky well patterns created during drilling. Although drillers aim
to drill a constant inclination hole in the pay zone, the more frequent
outcome is a sinusoidal wellbore trajectory. The two factors, which
play an important role in wellbore tortuosity, are the inclination and
side force at bit. A constant inclination horizontal well can only be
drilled if the bit face is maintained perpendicular to longitudinal axis
of bottom hole assembly (BHA) while keeping the side force nil at
the bit. This approach assumes that there exists no formation force at
bit. Hence, an appropriate BHA can be designed if bit side force and
bit tilt are determined accurately. The Artificial Neural Network
(ANN) is superior to existing analytical techniques. In this study, the
neural networks have been employed as a general approximation tool
for estimation of the bit side forces. A number of samples are
analyzed with ANN for parameters of bit side force and the results
are compared with exact analysis. Back Propagation Neural network
(BPN) is used to approximation of bit side forces. Resultant low
relative error value of the test indicates the usability of the BPN in
this area.
Abstract: The purpose of this paper is to provide a practical
example to the Linear Quadratic Gaussian (LQG) controller. This
method includes a description and some discussion of the discrete
Kalman state estimator. One aspect of this optimality is that the
estimator incorporates all information that can be provided to it. It
processes all available measurements, regardless of their precision, to
estimate the current value of the variables of interest, with use of
knowledge of the system and measurement device dynamics, the
statistical description of the system noises, measurement errors, and
uncertainty in the dynamics models.
Since the time of its introduction, the Kalman filter has been the
subject of extensive research and application, particularly in the area
of autonomous or assisted navigation. For example, to determine the
velocity of an aircraft or sideslip angle, one could use a Doppler
radar, the velocity indications of an inertial navigation system, or the
relative wind information in the air data system. Rather than ignore
any of these outputs, a Kalman filter could be built to combine all of
this data and knowledge of the various systems- dynamics to
generate an overall best estimate of velocity and sideslip angle.
Abstract: Combining energy efficiency with renewable energy
sources constitutes a key strategy for a sustainable future. The wind
power sector stands out as a fundamental element for the
achievement of the European renewable objectives and Portugal is no
exception to the increase of the wind energy for the electricity
generation. This work proposes an optimization model for the long
range electricity power planning in a system similar to the
Portuguese one, where the expected impacts of the increasing
installed wind power on the operating performance of thermal power
plants are taken into account. The main results indicate that the
increasing penetration of wind power in the electricity system will
have significant effects on the combined cycle gas power plants
operation and on the theoretically expected cost reduction and
environmental gains. This research demonstrated the need to address
the impact that energy sources with variable output may have, not
only on the short-term operational planning, but especially on the
medium to long range planning activities, in order to meet the
strategic objectives for the energy sector.
Abstract: This paper proposes a novel approach that combines statistical models and support vector machines. A hybrid scheme which appropriately incorporates the advantages of both the generative and discriminant model paradigms is described and evaluated. Support vector machines (SVMs) are trained to divide the whole speakers' space into small subsets of speakers within a hierarchical tree structure. During testing a speech token is assigned to its corresponding group and evaluation using gaussian mixture models (GMMs) is then processed. Experimental results show that the proposed method can significantly improve the performance of text independent speaker identification task. We report improvements of up to 50% reduction in identification error rate compared to the baseline statistical model.
Abstract: In this paper, we introduce a robust state feedback controller design using Linear Matrix Inequalities (LMIs) and guaranteed cost approach for Takagi-Sugeno fuzzy systems. The purpose on this work is to establish a systematic method to design controllers for a class of uncertain linear and non linear systems. Our approach utilizes a certain type of fuzzy systems that are based on Takagi-Sugeno (T-S) fuzzy models to approximate nonlinear systems. We use a robust control methodology to design controllers. This method not only guarantees stability, but also minimizes an upper bound on a linear quadratic performance measure. A simulation example is presented to show the effectiveness of this method.
Abstract: In the present study, an attempt was made to examine
the potential of aerobic mixed culture for decolourization of Remazol Black B dye in batch reactors. The effect of pH, temperature, inoculum, initial concentration of dye and initial concentration of
glucose was studied with an aim to determine the optimal conditions
required for maximum decolourization and degradation. The culture
exhibited maximum decolourization ability at pH between 7-8 and at
30°C. A 10% (v/v) inoculum and 1% (w/v) glucose concentration
were found to be the optimum for decolourization. A maximum of
98% decolourization was observed at 25 ppm initial concentration of
dye after 18 hours of incubation period. At higher dye concentration
of 300 ppm, the removal in colour was found to be 75% in 48 hours of incubation period. The results show that the enriched mixed culture from activated sludge has good potential in removal of Remazol Black B dye from wastewater under aerobic conditions.
Abstract: In this paper, an approach to reduce the computation steps required by fast neural networksfor the searching process is presented. The principle ofdivide and conquer strategy is applied through imagedecomposition. Each image is divided into small in sizesub-images and then each one is tested separately usinga fast neural network. The operation of fast neuralnetworks based on applying cross correlation in thefrequency domain between the input image and theweights of the hidden neurons. Compared toconventional and fast neural networks, experimentalresults show that a speed up ratio is achieved whenapplying this technique to locate human facesautomatically in cluttered scenes. Furthermore, fasterface detection is obtained by using parallel processingtechniques to test the resulting sub-images at the sametime using the same number of fast neural networks. Incontrast to using only fast neural networks, the speed upratio is increased with the size of the input image whenusing fast neural networks and image decomposition.
Abstract: Cast metal inlays can be used on molars requiring a
class II restoration instead amalgam and offer a durable alternative.
Because it is known that class II inlays may increase the
susceptibility to fracture, it is important to ensure optimal
performance in selection of the adequate preparation design to reduce
stresses in teeth structures and also in the restorations. The aim of the
study was to investigate the influence of preparation design on stress
distribution in molars with different class II preparations and in cast
metal inlays. The first step of the study was to achieve 3D models in
order to analyze teeth and cast metal class II inlays. The geometry of
the intact tooth was obtained by 3D scanning using a manufactured
device. With a NURBS modeling program the preparations and the
appropriately inlays were designed. 3D models of first upper molars
of the same shape and size were created. Inlay cavities designs were
created using literature data. The geometrical model was exported
and the mesh structure of the solid 3D model was created for
structural simulations. Stresses were located around the occlusal
contact areas. For the studied cases, the stress values were not
significant influenced by the taper of the preparation. it was
demonstrated stresses are higher in the cast metal restorations and
therefore the strength of the teeth is not affected.
Abstract: Wheat germ has a balanced amino acid composition of the protein, which is well digested by enzymes in the gastrointestinal tract of humans, a high content of vitamins, minerals and unsaturated acids. Introduction components grain food products will enrich their biologically important substances, giving these products a number of valuable properties and reducing their caloric.
A complex natural system of substances in foods will help replenish the body's need of essential nutrients, increasing its resistance to the harmful effects of the environment, prolong life. In this regard, there was a need for the development of production technology of protein complexes from wheat germ and then applying them in food, particularly in the dairy industry. Experimental studies were conducted to determine the number of herbal supplements on the sensory characteristics of the product. Studies have been conducted to determine the optimal process parameters of water activity and moisture content of the investigational product.
Abstract: The recommendation of the committee on corporate
governance for public companies in Nigeria, that the position of the
CEO be separated from board chair has generated serious debate
among scholars and practitioners. They have questioned the
appropriateness of implementing corporate governance model that is
based on Anglo-Saxon agency problem characterized by dispersed
ownership structure; where markets for corporate control, legal
regulation, and contractual incentives are the key governance
mechanisms. This paper strives to resolve the argument by adopting
an institutional perspective in testing the agency theory on board
duality. The study developed a theoretical and empirical model to
better understand how ownership structure influences agency conflict
and how such affects firm performance. Hence, the study examines
the relationship between CEO duality and firm performance using
two institutional ownership structures – dispersed ownership and
concentrated ownership structures. The empirical results show that
CEO duality is negatively correlated with firm performance in
Nigeria irrespective of the firm-s ownership structure. The findings
give credence to the recommendation of the Peterside Commission
on the need to separate the position of CEO from board chair.
Abstract: Plasma plume will be produced and arrive at spacecraft when the electric thruster operates on orbit. It-s important to characterize the thruster plasma parameters because the plume has significant effects or hazards on spacecraft sub-systems and parts. Through the ground test data of the desired parameters, the major characteristics of the thruster plume will be achieved. Also it is very important for optimizing design of Ion thruster. Retarding Potential Analyzer (RPA) is an effective instrument for plasma ion energy per unit charge distribution measurement. Special RPA should be designed according to certain plume plasma parameters range and feature. In this paper, major principles usable for good RPA design are discussed carefully. Conform to these principles, a four-grid planar electrostatic energy analyzer RPA was designed to avoid false data, and details were discussed including construction, materials, aperture diameter and so on. At the same time, it was designed more suitable for credible and long-duration measurements in the laboratory. In the end, RPA measurement results in the laboratory were given and discussed.
Abstract: This study investigated possible ways to improve the
efficiency of the platinum precipitation process using ammonium
chloride by reducing the platinum content reporting to the effluent.
The ore treated consist of five platinum group metals namely,
ruthenium, rhodium, iridium, platinum, palladium and a precious
metal gold. Gold, ruthenium, rhodium and iridium were extracted
prior the platinum precipitation process. Temperature, reducing
agent, flow rate and potential difference were the variables controlled
to determine the operation conditions for optimum platinum
precipitation efficiency. Hydrogen peroxide was added as the
oxidizing agent at the temperature of 85-90oC and potential
difference of 700-850mV was the variable used to check the
oxidizing state of platinum. The platinum was further purified at
temperature between 60-65oC, potential difference above 700 mV,
ammonium chloride of 200 l, and at these conditions the platinum
content reporting to the effluent was reduced to less than 300ppm,
resulting in optimum platinum precipitation efficiency and purity of
99.9%.
Abstract: This paper proposes a dual tree complex wavelet transform (DT-CWT) based directional interpolation scheme for noisy images. The problems of denoising and interpolation are modelled as to estimate the noiseless and missing samples under the same framework of optimal estimation. Initially, DT-CWT is used to decompose an input low-resolution noisy image into low and high frequency subbands. The high-frequency subband images are interpolated by linear minimum mean square estimation (LMMSE) based interpolation, which preserves the edges of the interpolated images. For each noisy LR image sample, we compute multiple estimates of it along different directions and then fuse those directional estimates for a more accurate denoised LR image. The estimation parameters calculated in the denoising processing can be readily used to interpolate the missing samples. The inverse DT-CWT is applied on the denoised input and interpolated high frequency subband images to obtain the high resolution image. Compared with the conventional schemes that perform denoising and interpolation in tandem, the proposed DT-CWT based noisy image interpolation method can reduce many noise-caused interpolation artifacts and preserve well the image edge structures. The visual and quantitative results show that the proposed technique outperforms many of the existing denoising and interpolation methods.
Abstract: Mathematical models can be used to describe the
dynamics of the spread of infectious disease between susceptibles
and infectious populations. Dengue fever is a re-emerging disease in
the tropical and subtropical regions of the world. Its incidence has
increased fourfold since 1970 and outbreaks are now reported quite
frequently from many parts of the world. In dengue endemic regions,
more cases of dengue infection in pregnancy and infancy are being
found due to the increasing incidence. It has been reported that
dengue infection was vertically transmitted to the infants. Primary
dengue infection is associated with mild to high fever, headache,
muscle pain and skin rash. Immune response includes IgM antibodies
produced by the 5th day of symptoms and persist for 30-60 days. IgG
antibodies appear on the 14th day and persist for life. Secondary
infections often result in high fever and in many cases with
hemorrhagic events and circulatory failure. In the present paper, a
mathematical model is proposed to simulate the succession of dengue
disease transmission in pregnancy and infancy. Stability analysis of
the equilibrium points is carried out and a simulation is given for the
different sets of parameter. Moreover, the bifurcation diagrams of our
model are discussed. The controlling of this disease in infant cases is
introduced in the term of the threshold condition.
Abstract: There has been a growing interest in the oxygenation
by plunging water jets in the last few years due to their inherent
advantages, like energy-efficient, low operation cost, etc. Though a
lot of work has been reported on the oxygen-transfer by single
plunging water jets but very few studies have been carried out using
multiple plunging jets. In this paper, volumetric oxygen-transfer
coefficient and oxygen-transfer efficiency has been studied
experimentally for multiple inclined plunging jets (having jet plunge
angle of 60 0 ) in a pool of water for different configurations, in
terms of varying number of jets and jet diameters. This research
suggests that the volumetric oxygen-transfer coefficient and oxygentransfer
efficiency of the multiple inclined plunging jets for air-water
system are significantly higher than those of a single vertical as well
as inclined plunging jet for same flow area and other similar
conditions. The study also reveals that the oxygen-transfer increase
with increase in number of multiple jets under similar conditions,
which will be most advantageous and energy-efficient in practical
situations when large volumes of wastewaters are to be treated. A
relationship between volumetric oxygen-transfer coefficient and jet
parameters is also proposed. The suggested relationship predicts the
volumetric oxygen-transfer coefficient for multiple inclined plunging
jet(s) within a scatter of ±15 percent. The relationship will be quite
useful in scale-up and in deciding optimum configuration of multiple
inclined plunging jet aeration system.
Abstract: The two agro-ecological zones became the focus of
the study because of violent nature of the incessant conflict in the
zones. The available register of farmers association was the sampling
frame work where ten percent (61) farmers per state were randomly
sampled. Data were collected and analysed using z-test. The research
findings revealed tree crops and grains production enterprises ranked
higher in Osun (rain fed zones) and Taraba states (savannah zones)
respectively. Osun state entrepreneur felt the effect of the conflict on
their enterprises more than Tarba state. The reasons adduced for
severity of the conflict on enterprises are majority (77.0%) migrated
and (75.5%) of them were not allowed to enter their farms during and
when conflict deescalated unlike situation in Taraba state. The
different in enterprises production level between the two agroecological
zone was statistically significant at p
Abstract: Two group of kids (“Safflower cake" and “Control") were fed ad libitum with pelleted total mixed rations. After a 7-days adaptation period, the diet of the “Safflower cake" group were supplemented with 20% of safflower cake. The kids were slaughtered at 96 days of age. Dietary safflower cake did not affect the growth traits of kids. In addition, kids fed experimental diet showed a lower feed intake and consequently a better feed conversion ratio in comparison to the “Control" group. The use of safflower decreased the level of SFA and increased the level of MUFA in kid meat. The level of PUFA was higher in lipid extracted from animals feeding “Control“ diet even if the UFA level was lower. Furthermore, lipid extracted from animals feeding control diet contained more ω6 fatty acids in comparison to kids feeding experimental diet while the opposite trend was observed for the level of ω3 fatty acids. The ω6 to ω3 ratio was significantly affected by diet and in particular this ratio decreased in meat of kids fed experimental diet. Our results indicate that intramuscular fatty acid composition of kid meat can be improved from a human health perspective by inclusion of safflower cake in the diet.
Abstract: Pleurotus ostreatus is a common edible mushroom with a number of properties that can help to solve the nutritional and economical problems of people in Chiapas, Mexico. The objective of this project was to produce the mushroom under a sustainable management in which only regional products were allowed as a way to promote the cultivation and consumption of Pleurotus ostreatus; 5 different substrates were tested as well as 2 sanitation methods. The obtained results showed that the highest yields were obtained using corn husk and a thermal sanitation method. Pests and diseases were not a problem during the project but they appeared more in the substrates sanitized with calcium hydroxide.
Abstract: Paddy being cultivated since about 10,000 years B.C in Ganga Valley in India, its production reached up to 99 million tons in the year 2012. BGA are of much ecological importance for maintaining the soil fertility and reclaiming the alkalinity. In present investigation attempts were made to identify the local cyanobacterial genera from the paddy fields, BGA application for green farming enabling the paddy to utilize more amount of nitrogen released and to examine its impact along with Urea upon growth and yield responses of the Paddy crop. It was observed that combined treatment of BGA with Urea proved better response in almost all growth parameters and yield attributes except number of tillers/ Plant and grains/ panicle as compared to application of either Urea or BGA alone. The Paddy growers should be encouraged to adopt BGA along with Urea as source of Nitrogen for Paddy cultivation.
Abstract: In a field experiment, growth parameters of soybean
cultivars in different weeding regimes was investigated. The trial was
split plot in a randomized complete block design. The four cultivars
and two lines of soybean (Glycine max L.) including: Sahar, Hill,
Sari, Telar, 032 and 033 in main plot and weeding regime consist of
no weeding (control), one weeding (35 days after planting) and two
weeding (35+20 days after planting) were randomized in sub plot.
The results showed that during the growth season 033 had the highest
dry matter in two weeding. In two weeding regime the dry matter
decreased. ). In all weeding regimes 033 had the highest CGR (Figs.
3a, 3b and 3c), which cleared this cultivar ability compare to the
others. This cultivar by increasing its leaf area could do more
photosynthesis, so, have a higher CGR.