bluuebunny/crossref_metadata_2025 huggingface dataset:
Robust Longitudinal Aircraft- Control Based on an Adaptive Fuzzy-Logic Algorithm
Authors: Elshafei Abdel- Latif
Published: May 2017

To study the aircraft response to a fast pull-up manoeuvre, a short period approximation of the longitudinal model is considered. The model is highly nonlinear and includes parametric uncertainties. To cope with a wide range of command signals, a robust adaptive fuzzy logic controller is proposed. The proposed controller adopts a dynamic inversion approach. Since feedback linearization is practically imperfect, robustifying and adaptive components are included in the control law to compensate for modeling errors and achieve acceptable tracking errors. Two fuzzy systems are implemented. The first system models the nominal values of the system’s nonlinearity. The second system is an adaptive one that compensates for modeling errors. The derivation of the control law based on a dynamic game approach is given in detail. Stability of the closed-loop control system is also verified. Simulation results based on an F16-model illustrate a successful tracking performance of the proposed controller.
Towards Formulation of a Complex Binary Number System
Authors: Jamil Tariq , Blest David , Al-Habsi Amer
Published: May 2017

For years complex numbers have been treated as distant relatives of real numbers despite their widespread applications in the fields of electrical and computer engineering. These days computer operations involving complex numbers are most commonly performed by applying divide-and-conquer technique whereby each complex number is separated into its real and imaginary parts, operations are carried out on each group of real and imaginary components, and then the final result of the operation is obtained by accumulating the individual results of the real and imaginary components. This technique forsakes the advantages of using complex numbers in computer arithmetic and there exists a need, at least for some problems, to treat a complex number as one unit and to carry out all operations in this form. In this paper, we have analyzed and proposed a (–1–j)-base binary number system for complex numbers. We have discussed the arithmetic operations of two such binary numbers and outlined work which is currently underway in this area of computer arithmetic.
Deregulation of Electricity Supply Industry in Oman
Authors: Al-Maghderi Hamed S. , Ramsay Bruce
Published: May 2017

This paper examines the opportunities available and the conditions needed for the deregulation of the Electricity Supply Industry (ESI), with particular reference to the Sultanate of Oman. The paper highlights the general issues of regulation required to encourage competition in the ESI.  After that, the discussion focuses on regulation methods in the privatized ESI by describing the regulators control through price caps setting for regulatees, the conduct regulation process, the rate of return regulation setting, and the spot market (the pool) contract. Finally, the prospects of restructuring and privatizing the ESI in the Sultanate of Oman are examined by reviewing the current structure of the industry and government objectives in deregulation of the electricity sector as well as the regulation framework.
Intelligent Techniques for Power Systems Vulnerability Assessment
Authors: El-Sharkawi Mohamed A.
Published: May 2017

With power grids considered national security matters, the reliable operation of the system is of top priority to utilities.  This concern is amplified by the utility’s deregulation, which increases the system’s openness while simultaneously decreasing the applied degree of control.  Vulnerability Assessment (VA) deals with the power system’s ability to continue to provide service in case of an unforeseen catastrophic contingency.  Such contingencies may include unauthorized tripping, breaks in communication links, sabotage or intrusion by external agents, human errors, natural calamities and faults.  These contingencies could lead to a disruption of service to part or all of the system.  The service disruption is known as outage or blackout.  The paper outlines an approach by which feature extraction and boundary tracking can be implemented to achieve on line vulnerability assessment.
Surface Preparation of InAs (110) Using Atomic Hydrogen
Authors: Veal T.D. , McConville C.F. , Al-Harthi S.H.
Published: May 2017

Atomic hydrogen cleaning has been used to produce structurally and electronically damage-free InAs(110) surfaces.  X-ray photoelectron spectroscopy (XPS) was used to obtain chemical composition and chemical state information about the surface, before and after the removal of the atmospheric contamination. Low energy electron diffraction (LEED) and high-resolution electron-energy-loss spectroscopy (HREELS) were also used, respectively, to determine the surface reconstruction and degree of surface ordering, and to probe the adsorbed contaminant vibrational modes and the collective excitations of the clean surface. Clean, ordered and stoichiometric  InAs(110)-(1×1) surfaces were obtained by exposure to thermally generated atomic hydrogen at a substrate temperature as low as 400ºC.  Semi-classical dielectric theory analysis of HREEL spectra of the phonon and plasmon excitations of the clean surface indicate that no electronic damage or dopant passivation were induced by the surface preparation method.
Regression Estimator Using Double Ranked Set Sampling
Authors: Samawi Hani M. , Tawalbeh Eman M.
Published: May 2017

The performance of a regression estimator based on the double ranked set sample (DRSS) scheme, introduced by Al-Saleh and Al-Kadiri (2000), is investigated when the mean of the auxiliary variable X is unknown. Our primary analysis and simulation indicates that using the DRSS regression estimator for estimating the population mean substantially increases relative efficiency compared to using regression estimator based on simple random sampling (SRS) or ranked set sampling (RSS) (Yu and Lam, 1997) regression estimator.  Moreover, the regression estimator using DRSS is also more efficient than the naïve estimators of the population mean using SRS, RSS (when the correlation coefficient is at least 0.4) and DRSS for high correlation coefficient (at least 0.91.) The theory is illustrated using a real data set of trees.
Steady State Analysis of a UPFC as Voltage Regulator for Optimal Position in the Transmission Line
Authors: Al-Mawsawi S. Ali , Qader Mohammed R.
Published: May 2017

It has recently been illustrated that the Unified Power Flow Controller (UPFC) installation location plays an important role in effecting nonlinearly in the UPFC steady state performance of the system. A Pulse Width Modulation (PWM) based on UPFC as a voltage regulator is modeled and analyzed to investigate the optimal position in the transmission line. From the study made in this paper, it is shown that the location of UPFC plays a significant part in effecting nonlinearly. It is also found from the simulation results that the distribution of the active and reactive power flows can be controlled by varying the modulation index of the device.
Analysis of Fire Data in Oman
Authors: Al-Jabri K.S. , Hago A.W. , Alnuaimi A.S. , Al-Mahrooqi S.
Published: May 2017

The aim of this study is to illustrate the problem of fire accidents in the Sultanate of Oman and their causes in order to find out how the existing data could be used as a base to improve fire resistance, to detect the weak points (vulnerability to fire) in existing structures, and to minimize fire occurrences in places where it is high. This will also provide useful recommendations with regard to fire safety including causes, people’s awareness and education, etc.  Fire data in Oman were collected from two sources: The Directorate General of Civil Defence (Public Relations Department) and Sultan Qaboos University library. The collected data represent the number of fires in Oman during the last decade.  It also includes fire distribution by type and averages.  The analysis shows that there is a linear increase in the number of fire accidents in the last decade with time.  Many factors are included as potential sources, which are explained in the paper, and suggestions are made for possible control.
Some Aspects of the Anatomy and Histology of Digestive Tracts in Two Sympatric Species of Freshwater Fishes
Authors: Ba-Omar Taher , Victor Reginald , Tobias Daniel
Published: May 2017

Comparative anatomy and histology of the digestive tracts of two sympatric species of freshwater fish, Aphanius dispar (Cyprinodontidae) and Garra barreimiae (Cyprinidae) are studied. Morphometric measurements of alimentary canal such as length and the number and height of rugae in sections have been made for both species. Relationships between these morphometric characters and the total length of fish have been evaluated. The ratio between the length of alimentary canal and total length of fish in both species reflects their feeding habits. Histology of the ‘stomach’ and ‘intestine’ of these two species as shown by light microscopy has been described and compared. Results of this study are used to discuss the query whether these species have true stomachs.
Laboratory Evaluation of Ground Tire Rubber in Stone Mastic Asphalt
Authors: Muniandy R. , Selim A. A. , Hassim S. , Omar H.
Published: May 2017

Stone mastic asphalt (SMA) is a gap-graded mix whereby stiffer asphalt cement is required to bind the stone matrix or arrangement of stones together. Although various asphalt additives are traditionally available, the use of rubber crumbs in SMA is still a new rresearch endeavor. Many countries around the world are facing serious problems on what to do with reject or discarded tires. In the present study, commercial truck tires, containing 70% natural rubber, were ground and pre-blended in 80-100 penetration asphalt for use in SMA mixtures. An assessment was made of the laboratory performance of rubberized SMA in terms of stability, resilent modulus, dynamic creep and tensile strength ratio. It was observed that the performance of SMA with ground tire rubber was for superior as compared to SMA mix with unmodified asphalt. Sulfur and Styrene Butadeline Rubber (SBR) were used in rubberized SMA mixes as additives to test the sensitivity of SMA mixtures. As standard practice a 0.3% newly developed cellulose oil palm fiber was used in SMA to minimize the asphalt drain-down effects.
Takagi-Sugeno Neuro-Fuzzy Modeling of a Multivariable Nonlinear Antenna System
Authors: Al-Gallaf E. A.
Published: May 2017

This article investigates the use of a clustered based neuro-fuzzy system to nonlinear dynamic system modeling. It is focused on the modeling via Takagi-Sugeno (T-S) modeling procedure and the employment of fuzzy clustering to generate suitable initial membership functions. The T-S fuzzy modeling has been applied to model a nonlinear antenna dynamic system with two coupled inputs and outputs. Compared to other well-known approximation techniques such as artificial neural networks, the employed neuro-fuzzy system has provided a more transparent representation of the nonlinear antenna system under study, mainly due to the possible linguistic interpretation in the form of rules. Created initial memberships are then employed to construct suitable T-S models. Furthermore, the T-S fuzzy models have been validated and checked through the use of some standard model validation techniques (like the correlation functions). This intelligent modeling scheme is very useful once making complicated systems linguistically transparent in terms of the fuzzy if-then rules.
A Modified Approach in Modeling and Calculation of Contact Characteristics of Rough Surfaces
Authors: Abdo J.A.
Published: May 2017

A mathematical formulation for the contact of rough surfaces is presented. The derivation of the contact model is facilitated through the definition of plastic asperities that are assumed to be embedded at a critical depth within the actual surface asperities. The surface asperities are assumed to deform elastically whereas the plastic asperities experience only plastic deformation. The deformation of plastic asperities is made to obey the law of conservation of volume. It is believed that the proposed model is advantageous since (a) it provides a more accurate account of elasticplastic behavior of surfaces in contact and (b) it is applicable to model formulations that involve asperity shoulder-to shoulder contact. Comparison of numerical results for estimating true contact area and contact force using the proposed model and the earlier methods suggest that the proposed approach provides a more realistic prediction of elastic-plastic contact behavior.
Heat Transfer Enhancement In a Ribbed Duct
Authors: Jalil J.M. , Murtadha T.K. , Kadom H.M.
Published: May 2017

The rib enhancement of heat transfer in a duct is studied numerically and experimentally, where hot air passes through a duct (0.04 x 0.16 x 1.15 m3) with different rib arrangement. The arranments are lower 12-rib arrangement; upper 12 rib arrangement and 24 rib staggered arrangement. The staggered arrangement gives better performance than the others. Also, the angle of attack was studied for lower arrangement, three different values were tested (45°, 60° and 90°). Angle of 60° gives better performance. Numerically, the three-dimension continuity, Navier-Stokes and energy   by finite volume method of flow of air through (0.04 x 0.16 x 0.6 m3). Validation of the code was performed by comparing the numerical result with the results obtained experimentally for staggered arrangement only. The agreement seems acceptable. The numerical studies were extended to study the case of cold air passing through hot ribbed duct.
Sensitivity Studies for Propane Oxidative Dehydrogenation to Propylene in Circulating Fluidized Bed
Authors: Fakeeha A.H. , Soliman M.A. , Ibrahim A.A.
Published: May 2017

In this paper, simulation and sensitivity studies for propane oxidative dehydrogenation to which were propylene in a circulating fluidized bed is undertaken using a previously developed model. Various experimental kinetics, obtained by several investigators for the reaction using different catalysts, are employed in this study. A comparison is made for the performance of certain catalysts when used in a circulating fluidized bed reactor. The effects of changing reaction temperature, solid circulation rate, feed composition, pressure, and gas superficial velocity on reactant conversion and product selectivity and yields are studied. It was found that the catalyst prepared by Ramos et al. is superior to the others with respect to yield.
Microwave-Assisted Extraction of Essential Oil from Eucalyptus: Study of the Effects of Operating Conditions
Authors: Saoud A.A. , Yunus R.M. , Aziz R.A.
Published: May 2017

Classical extraction of essential oil such as Soxhlet and steam distillation is still a formidable and time-solvent consuming. Microwave assisted process (MAP) is used to accelerate the extraction process of target compounds. It can be used for the extraction of compounds from various plants and animal tissues, or the extraction of undesirable components from raw materials. The investigation of microwave extraction of eucalyptus (globules ) essential oil using ethanol as solvent was carried out. The influence of material (eucalyptus)/solvent (ethanol) ratio, required doses of microwave, and time of microwave exposure on extraction efficiency, was studied.
Nonlinear Predictive Control With End Point Constraints
Authors: Hedjar R.
Published: May 2017

The optimal nonlinear predictive control structure with end point constraints is presented, which provides asymptotic tracking of smooth reference trajectories. The controller is based on a finite horizon continuous time minimization of nonlinear predicted tracking errors. A key feature of the control law is that its implementation does not need to perform an online optimization, and asymptotic tracking of smooth reference signal is guaranteed. The proposed control scheme is applied to planning motions problem of a mobile robot. Simulations results are performed to validate the tracking performance of the proposed controller.
Settlement of Shallow Circular Foundations with Structural Skirts Resting on Sand
Authors: Al-Aghbari M.Y.
Published: May 2017

This paper presents the findings of an experimental study concerning a method of reducing the settlement of shallow circular foundations on sand. It involves the use of structural skirts fixed to the edges of foundations. The experiments were performed in a large tank setting and the footing was instrumented in order to measure normal stresses and settlement. A series of tests were conducted to study the settlements of a circular footing with and without structural skirts. Test results indicate that this type of reinforcement reduces the settlement of subgrade and modifies the stress-displacement behaviour of the footing. A settlement Reduction Factor (SRF) was proposed, which takes into account the influence of various parameters that affect settlements. Results show that the use of structural skirts can produce enhanced settlement reduction in the range of 0.1 to 1.0 depending on stress applied and skirt depth. Given these levels of settlements reduction, it is concluded that the use of structural skirts to reduce the settlement of shallow foundations on dense sand is of practical significance. Further testing is recommended for different foundation shapes with structural skirts resting on different soil types.
Solar-Driven Air-Conditioning Cycles: A Review
Authors: Abu-Zour A. M. , Riffat S. B.
Published: May 2017

Most conventional cooling/refrigeration systems are driven by fossil fuel combustion, and therefore give rise to emission of environmentally damaging pollutants. In addition, many cooling systems employ refrigerants, which are also harmful to the environment in terms of their Global Warming Potential (GWP) and Ozone Depletion Potential (ODP). Development of a passive or hybrid solar-driven air-conditioning system is therefore of interest as exploitation of such systems would reduce the demand for grid electricity particularly at times of peak load. This paper presents a review of various cooling cycles and summarises work carried out on solar-driven air-conditioning systems.
Design of a Rotary Kiln for Production of Sarooj
Authors: W. Hago A. , Al-Rawas A. A.
Published: May 2017

Sarooj is a local term used for pozzolana. It has been used extensively as a hydraulic binder in buildings, hydraulic installations, forts and castles, and in the renovation of historical monuments. It is produced by burning specific clay soil that possesses adequate quantities of silica, alumina and iron oxides. In the past, the material was produced using a large amount of energy most of which is wasted by blowing winds. The burning system was usually thermally inefficient, and the output is rarely checked for quality. Test on products produced by using the traditional method may yield poor quality Sarooj due to inadequate burning or over burning or even insufficient grinding in the end. In this research, extensive experimentation has been performed on the method of production of Sarooj to determine the factors influencing Sarooj quality. Based on these factors, a new method of production is proposed. In this method, a fully mobile kiln was designed to produce Sarooj on the site. The kiln can produce 200 kg/h of Sarooj, and can be installed within one hour of arriving on the site. It can be towed by a tractor or a normal vehicle to the desired location, connected to the natural gas supply and the electric power. The construction is light, compact, and easy to start and shut down. In this paper, the plant is described in detail, together with some preliminary results of testing done on Sarooj produced by the kiln. Full details of tests on the product of the kiln will be given in a subsequent paper.
Identification of Friction/Vibration Interaction between Solids
Authors: Abdo J. A. , Al-Rawahi N.
Published: May 2017

Dry-friction forces have been shown to depend not only on the characteristics of the surface in contact but also on the dynamic interaction of the contacting bodies. A viscoelastic mathematical model that accounts for the interaction at micro-scale of rough surfaces is developed. The mathematical formulation relates the tribological events at microscopic and macroscopic scales vibration response of a "mass on moving belt". The viscoelastic properties are presented by combining loss modulus with Young's modulus to obtain a differential operator on the interference, reminiscent of the Kelvin-Voigt model. The analysis of the system establishes the relation between friction force and speed and supports observed behavior of many systems with friction. The derivations do not rely on a phenomenological account of friction, which requires a presumed friction coefficient. Instead the friction force is accounted for as a result of interaction of the rough surfaces. This has led to a set of nonlinear ordinary differential equations that directly relate the vibration of the system to the surface parameters. It is shown that, as a result of coupling of the macrosystem's dynamics and contact, there are combinations of parameters at micro- and macroscale that yield negative slope in friction force/sliding speed relation, a well known source of dynamic instability.
Recycling of Reclaimed Asphalt Pavement in Portland Cement Concrete
Authors: Al-Oraimi Salim , F. Hassan Hossam , Hago Abdulwahid
Published: May 2017

Reclaimed Asphalt Pavement (RAP) is the result of removing old asphalt pavement material. RAP consists of high quality well-graded aggregate coated with asphalt cement. The removal of asphalt concrete is done for reconstruction purposes, resurfacing, or to obtain access to buried utilities. The disposal of RAP represents a large loss of valuable source of high quality aggregate. This research investigates the properties of concrete utilizing recycled reclaimed asphalt pavement (RAP). Two control mixes with normal aggregate were designed with water cement ratios of 0.45 and 0.5. The control mixes resulted in compressive strengths of 50 and 33 MPa after 28 days of curing. The coarse fraction of RAP was used to replace the coarse aggregate with 25, 50, 75, and 100% for both mixtures. In addition to the control mix (0%), the mixes containing RAP were evaluated for slump, compressive strength, flexural strength, and modulus of elasticity. Durability was evaluated using surface absorption test.
Waste Plastic-Modified Bitumen: Rheological Study
Authors: Abdel-Goad Mahmoud
Published: May 2017

Bitumen blends were prepared for road applications by the introduction of 9% of waste Polyethylene by weight (9 wt%). The relaxation stress, relaxation and retardation spectrum and viscosity of bitumen blends were studied at different temperatures and compared to those of the original pure bitumen. These properties were tested using an ARESRheometer (Rheometric Scientific, Co.) equipment. The measurements were performed in the dynamic mode, plate-plate geometry of 8 mm diameter over the temperature range from -10 to 60°C and angular frequency (ω) varied from 10-1 to 102 radian/s. The relaxation stress and viscosity were modified by the addition of waste PE. The results also indicate that the incorporation of the waste PE enhances stability of the bitumen blends.
A Less Complex Algorithmic Procedure for Computing Gray Codes
Authors: Ahmad Afaq , Bait Suwailam Mohammed M.
Published: May 2017

The purpose of this paper is to present a new and faster algorithmic procedure for generating the n bi Gray codes. Thereby, through this paper we have presented the derivation, design and implementation of a newly developed algorithm for the generation of an n-bit binary reflected Gray code sequences. The developed algorithm is stemmed from the fact of generating and properly placing the min-terms from the universal set of all the possible min-terms [m0 m1 m2 …. mN] of Boolean function of n variables, where, 0 < N <  2n-1. The resulting algorithm is in concise form and trivial to implement. Furthermore, the developed algorithm is equipped with added attributes of optimizing of time and space while executed.
Pyrolysis of Coconut Shell: An Experimental Investigation
Authors: Ganapathy Sundaram E. , Natarajan E.
Published: May 2017

Fixed-bed slow pyrolysis experiments of coconut shell have been conducted to determine the effect of pyrolysis temperature, heating rate and particle size on the pyrolysis product yields. The effect of vapour residence time on the pyrolysis yield was also investigated by varying the reactor length. Pyrolysis experiments were performed at pyrolysis temperature between 400 and 600°C with a constant heating rate of 60°C/min and particle sizes of 1.18-1.80 mm. The optimum process conditions for maximizing the liquid yield from the coconut shell pyrolysis in a fixed bed reactor were also identified. The highest liquid yield was obtained at a pyrolysis temperature of 550 °C, particle size of 1.18-1.80 mm, with a heating rate of 60 °C/min in a 200 mm length reactor. The yield of obtained char, liquid and gas was 22-31 wt%, 38-44 wt% and 30-33 wt% respectively at different pyrolysis conditions. The results indicate that the effects of pyrolysis temperature and particle size on the pyrolysis yield are more significant than that of heating rate and residence time. The various characteristics of pyrolysis oil obtained under the optimum conditions for maximum liquid yield were identified on the basis of standard test methods.
Effect of Cd on Microstructure and Dry Sliding Wear Behavior of (Al-12%Si) Alloy
Authors: Abbass Muna K.
Published: May 2017

The aim of the present research is to study the effect of cadmium addition on microstructure and wear behavior of the alloy (Al-12%Si) under dry sliding conditions. Wear behavior was studied by using the Pin-On- Disc technique under different conditions at applied loads 5-20 N, at constant sliding speed and in constant time. The steel disc hardness was 35HRc. All alloys were prepared with different percentages of cadmium (1.0, 2.0, 3.0) wt%. Also the base alloy was prepared by melting and pouring the molten metal in a metallic mold. It was found that the cadmium addition to Al-Si matrix decreases the wear rate and improves the wear properties for alloys containing -Cd under loads above 10N. It was also found that the alloy Al-12%Si containing 3%Cd is the best alloy in wear resistance and friction coefficient. This is due to presence of the Cd-phase as cuboids or hard particles distributed in a eutectic matrix which reduces the friction coefficient at high loads (20N).
Estimating Optimum Compaction Level for Dense-Graded Hot-Mix Asphalt Mixtures
Authors: Al Shamsi Khalid , Mohammad Louay N.
Published: May 2017

A critical step in the design of asphalt mixtures is laboratory compaction. Laboratory compaction should reflect field compaction and should produce mixtures that are economical and possess high structural stability. During the compaction process, asphalt mixtures are subjected to certain amount of compaction energy in order to achieve the required density. The Superpave volumetric mix design is based on compacting HMA mixtures to a specified compaction level described by the number of gyrations from the Superpave gyratory compactor (SGC). This level is termed Ndes and represents the required energy (based on the traffic level expected) to densify the mixture to a 4% air voids level. This paper re-examines the Superpave compaction requirements through extensive laboratory investigation of the response of a number of asphalt mixtures to the applied compaction energy. It also presents an alternative method to estimate the number of gyrations at which a mixture first reaches an optimum aggregate interlock and hence prevents overcompaction problems that might result in unstable aggregate structures or dry asphalt mixtures. A total of 12 HMA mixtures were studied. During compaction, force measurement was made using the pressure distribution analyzer (PDA). The compaction characteristics of the mixtures were analyzed using data from the PDA and the traditional Superpave Gyratory Compactor (SGC) results.
Determination of Potential Profile In Planar Electronic Structures Using A Semi-Analytical Technique
Authors: Bourdoucen Hadj , Dehmas Mokrane , Yallaoui El-Bachir
Published: May 2017

In this paper, a semi-analytical technique known as the Method of Lines (MoL) with uniform and non-uniform discretization schemes is developed. The aim is to determine static potential profile in planar electronic structures. Even though this method has been known for some time, there has been reported work on its application to planar semiconductor device analysis for voltage profile determination. Since most current electronic devices are manufactured using planar and quasi-planar technology, the proposed algorithm is well suited for device analysis prior to fabrication. Compared with known popular methods such as Finite Difference and Finite Elements methods, the proposed technique is relatively simple, more accurate and unlike other methods, has no convergence problem. In addition to this, its semi-analytical nature, which consists of reducing one computing dimension, allows saving significant memory and computation time. Typical planar electronic structures are considered to demonstrate their suitability for these devices, and the obtained results are presented and discussed.
A Multi-Resolution Texture Image Retrieval Using Fast Fourier Transform
Authors: Abdesselam A.
Published: May 2017

Texture is an important visual property that characterizes a wide range of natural and artificial images which makes it a useful feature for retrieving images. Several approaches have been proposed to describe the texture contents of an image. In early research works, such as edge histograms-based techniques and co-occurrence-based approaches, texture descriptors were mainly extracted from the spatial domain. Later on, dual spaces (transform of spatial domain) such as frequency space or spaces resulting from Gabor or wavelet transforms were explored for texture characterization. Recent physiological studies showed that human visual system can be modeled as a set of independent channels of various orientations and scales, this finding motivated the proliferation of multi-resolution methods for describing texture images. Most of these methods are either wavelet-based or Gabor-based. This paper summarizes our recent study of the use of Fourier-based techniques for characterizing image textures. At first, a singleresolution Fourier-based technique is proposed and its performance is compared against the performance of some classical Fourier-based methods. The proposed technique is then extended into a multi-resolution version. Performance of the modified technique is compared against those of the single-resolution approach and some other multi-resolution approaches recently described in literature. Two performance indicators were used in this comparison: retrieval accuracy and execution time of the techniques.
Mutual Coupling Reduction Between Axial-Mode Helical Antennas using Single-Negative (SNG) Magnetic Metamaterials
Authors: Bait-Suwailam M. M. , Ramahi O.M.
Published: May 2017

This paper investigates the mutual coupling effects between axial-mode helical antenna arrays. Single-negative (SNG) magnetic metamaterials are developed and used in this work in order to reduce mutual coupling between axial-mode helical antennas used in multiple-input multiple-output systems. The inclusions considered here are composed of broadside coupled split-ring resonators. The magnetic permeability of those SNG inclusions have complex effective magnetic permeability response over a frequency band with high negative real part above the resonance and positive real part below the resonance. The SNG resonators are inserted between closely-spaced axial-mode helical antenna elements. Effective responses of the constitutive parameters of the developed magnetic inclusions are incorporated within the numerical models. It is shown that mutual coupling between the antenna elements can be reduced significantly by incorporating such magnetic inclusions. The SNG magnetic resonators work as antenna decoupler, and thus can be applied in a variety of antenna applications.
Transition of Gas-Liquid Stratified Flow in Oil Transport Pipes
Authors: Lakehal D. , Labois M. , Caviezel D. , Belhouachi B.
Published: May 2017

Large-Scale Simulation results of the transition of a gas-liquid stratified flow to slug flow regime in circular 3D oil transport pipes under turbulent flow conditions expressed. Free surface flow in the pipe is treated using the Level Set method. Turbulence is approached via the LES and VLES methodologies extended to interfacial two-phase flows. It is shown that only with the Level Set method the flow transition can be accurately predicted, better than with the two-fluid phase-average model. The transition from stratified to slug flow is found to be subsequent to the merging of the secondary wave modes created by the action of gas shear (short waves) with the first wave mode (high amplitude long wave). The model is capable of predicting global flow features like the onset of slugging and slug speed. In the second test case, the model predicts different kinds of slugs, the so-called operating slugs formed upstream that fill entirely the pipe with water slugs of length scales of the order of 2-4 D, and lower size (1-1.5 D) disturbance slugs, featuring lower hold-up (0.8-0.9). The model predicts well the frequency of slugs. The simulations revealed important parameter effects on the results, such as two-dimensionality, pipe length, and water holdup.
Inovação nas normas internacionais do novo relatório do auditor independente
Authors: Manoel Jorge , Quel Luiz Felipe
Published: May 2017

Historically, the independent audit profession faces a relevant challenge relating to the close of the users’ expectation gap of its report on the financial statements of companies. Throughout the years, studies of this matter were made to identify main causes. As a result, a new standard on the independent auditors’ report was internationally approved, which is applicable for financial statements of listed companies for the year ended on or after December 15, 2016 (for Brazilian listed entities, December 31st, as locally regulated). Among the main changes innovating the new independent audit report aiming to close the users’ expectation gap are: the reorganization of the paragraphs of the auditor report to reflect the importance of the subjects; the confirmation by the auditor of his independence in relation to the company he is auditing; material uncertainty related to the entity´s ability to continue operating (going concern concept) described in a specific section; the inclusion of a new paragraph for listed; companies detailing key audit matters (KAM) found during the audit (disclosure is optional for other companies); new section on other information that accompany the financial statements (for example management report) and the results of the audit procedures applied to it; the evaluation of management of its responsibility relating to the capacity of the company to continue in operation (going concern concept); a more comprehensive description of auditor’s responsibilities, including with respect to going concern. These changes compose the reply of the audit profession to close the user´s expectation gap in relation to the new auditor report. The one relating to the inclusion of the new paragraph detailing key audit matters identified during the audit process is key to respond to the users of the audit report and give them additional information for his sensitivity market investment analysis and decision making process.
Rabies surveillance in the United States during 2015
Authors: Birhane Meseret G. , Cleaton Julie M. , Monroe Ben P. , Wadhwa Ashutosh , Orciari Lillian A. , Yager Pamela , Blanton Jesse , Velasco-Villa Andres , Petersen Brett W. , Wallace Ryan M.
Published: May 2017

OBJECTIVE

To describe rabies and rabies-related events occurring during 2015 in the United States.

DESIGN

Observational study based on passive surveillance data.

ANIMALS

All animals submitted for rabies testing in the United States during 2015.

PROCEDURES

State and territorial public health programs provided data on animals submitted for rabies testing in 2015. Data were analyzed temporally and geographically to assess trends in domestic and sylvatic animal rabies cases.

RESULTS

During 2015, 50 states and Puerto Rico reported 5,508 rabid animals to the CDC, representing an 8.7% decrease from the 6,033 rabid animals reported in 2014. Of the 5,508 cases of animal rabies, 5,088 (92.4%) involved wildlife. Relative contributions by the major animal groups were as follows: 1,704 (30.9%) bats, 1,619 (29.4%) raccoons, 1,365 (24.8%) skunks, 325 (5.9%) foxes, 244 (4.4%) cats, 85 (1.5%) cattle, and 67 (1.2%) dogs. There was a 4.1% decrease in the number of samples submitted for testing in 2015, compared with the number submitted in 2014. Three human rabies deaths were reported in 2015, compared with only 1 in 2014. A 65-year-old man in Massachusetts was bitten by a rabid dog while abroad. A 77-year-old woman in Wyoming had contact with a bat. A 54-year-old man in Puerto Rico was bitten by a mongoose. The only connection among these 3 cases was that none received postexposure prophylaxis.

CONCLUSIONS AND CLINICAL RELEVANCE

Laboratory testing of animals suspected to be rabid remains a critical public health function and continues to be a cost-effective method to directly influence human rabies postexposure prophylaxis recommendations. (J Am Vet Med Assoc 2017;250:1117–1130)
DOSIS LETALES DE DIPTEREX 80 % P.S PARA EL CONTROL DE NAYADAS DE Gomphaeshna sp., Tramea cophysa y Tramea calverti (Odonata, Aeshnidae)
Authors: ALCANTARA-BOCANEGRA Fernando , GARCÍA-T. Juan , PADILLA-PÉREZ Palmira P. , DELGADO-VÁSQUEZ César
Published: May 2017

Las nayadas de Gomphaeshna sp., Tramea cophysa y Tramea calverti (Odonata), fueron manipuladas en laboratorio para establecer la dosis letal 100 % en períodos de 24 horas de tratamiento, con el insecticida fosforado Dipterex 80 % Polvo Soluble (“Trichlorfon”), 0,0 dimetil (2,2,2-triclor-1-hidroximetil) fosfonato. Se efectuó un experimento para Gomphaeshna sp. y otro para Tramea cophysa y Tramea calverti, en acuarios de vidrio, con concentraciones crecientes del insecticida. Para Gomphaeshna sp., se estableció una DL100 en 24 horas de 0,5 mg/l y para Tramea cophysa y Tramea calverti se  estableció una DL100 de 4,5 mg/l.
ESTUDIO CUANTITATIVO DE LA MACROFAUNA DEL SUELO EN DIFERENTES SISTEMAS DE USO DE LA TIERRA EN LA AMAZONÍA PERUANA
Authors: PASHANASI-AMASIFUEN Beto
Published: May 2017

La comunidad de macro-invertebrados del suelo fue evaluada en 22 sistemas de uso del suelo en las zonas de Yurimaguas y Pucallpa. Se separaron, manualmente, 10 muestras por sistema de uso de 25 cm x 25 cm x 30 cm durante la estación lluviosa.El bosque primario, no intervenido e intervenido, tiene una diversidad muy rica.Asimismo, su densidad (382 a 853 individuos/m ) y su biomasa, dominada poroligochaetas, isópteras y miriápodos (57,8 a 91,1 g peso fresco/m2), son bastante altas. Los cultivos de esta comunidad, cuya densidad es de 362 a 574 individuos/m y cuya biomasa es de 5,1 a 32,4 g peso fresco/m2, se encuentran severamente agotados. Las pasturas tienen baja diversidad. La densidad de su población varía en un rango de 654 a 1 034 individuos/m2. Su biomasa es tan alta como de 38,4 a 165,9 g peso fresco/m2, debido a la colonización de la lombriz peregrina, Pontoscolex corethrurus.En las purmas, la densidad poblacional está en un rango de 334 a 838 individuos/m2;mientras que la biomasa varía entra 4,2 y 102 g peso fresco/m2. Cabe destacar que, en algunos casos, la riqueza taxonómica es mayor que la del bosque primario. Finalmente, los sistemas agroforestales con cobertura de leguminosas tienen la más alta diversidad. Lo contrario ocurre en los sistemas con cobertura de malezas que están por debajo del bosque secundario. Su densidad poblacional se encuentra en un rango que va desde 557 hasta 2 896 individuos/m2, mientras que su biomasa varía entre 18,5 y 170,5 g peso fresco/m2, debido a la conservación de gran parte de la fauna del bosque primario que, además, es colonizada por especies oportunistas de terrenos disturbados (miriápodos, oligochaetas e isópteras).
LA PESQUERÍA COMERCIAL DE LORETO CON ÉNFASIS EN EL ANÁLISIS DE LA RELACIÓN ENTRE CAPTURA Y ESFUERZO PESQUERO DE LA FLOTA COMERCIAL DE IQUITOS, CUENCA DEL AMAZONAS (PERÚ)
Authors: TELLO-MARTÍN José Salvador , BAYLEY Peter
Published: May 2017

La información utilizada en este estudio fue recopilada por el Instituto de Investigaciones de la Amazonía Peruana (IIAP), la Dirección Regional de Pesquería de Loreto y la Asociación de Pescadores de Loreto. Para ser analizada, dicha información se separó en desembarques totales de la región Loreto y desembarques de la flota pesquera comercial de Iquitos. Los resultados indican que las especies grandes están siendo reemplazadas en los desembarques por especies más pequeñas, de alto rendimiento y de menor precio. Esto se debe a la mayor intensidad de pesca y a los cambios en las artes de pesca. Asimismo, se encontró evidencia de sobrepesca de crecimiento en algunas especies de grandes bagres y boquichico. No obstante ello, los rendimientos comerciales encontrados en similares niveles de esfuerzo han permanecido casi constantesa pesar de los cambios en la composición de las capturas detectadas en losúltimos años. Para el área de estudio, se determinó un esfuerzo de 0,3 pescadores por km2 y un rendimiento de 1,4 kg ha-1.
REPRODUCCIÓN INDUCIDA DE LA DONCELLA Pseudoplatystoma fasciatum y DESARROLLO EMBRIONARIO - LARVAL
Authors: PADILLA-PÉREZ Palmira P. , ALCANTARA-BOCANEGRA Fernando , ISMIÑO-ORBE Rosa A.
Published: May 2017

Los productos sexuales de doncella Pseudoplatystoma fasciatum fueron obtenidos mediante la inducción hormonal usando pituitaria de carpa y ovudal (D-alanina 6). La dosis de ovudal fue de 10mg/kg para las hembras y de 1mg/kg para los machos,mientras que la de pituitaria de carpa fue de 5mg/kg para las hembras y 1mg/kg para los machos. Los huevos son esféricos, semiflotantes y no adhesivos. Están protegidos externamente por una capa gelatinosa e, internamente, por un gran espacio perivitelínico. El diámetro de los huevos hidratados es de 8,5 μ. La eclosión se inició a las 14±2 horas de incubación a 27º C de temperatura. Al nacer, las larvas tienen una longitud total de 3,02±0,12 mm y presentan un saco vitelino. Después de 21 horas, se observaron los pigmentos oculares y comenzaron a desarrollarse las barbillas maxilares. A los 3 días, el saco vitelino se reabsorbe y se completa la conexión del tubo digestivo con la boca. A partir del cuarto día, las larvas consumenalimento vivo y tienen una longitud total de 5,82 ± 0,19 mm. En el décimo día, se define el primer patrón de coloración. En este periodo, las larvas tienen una longitud total de 10,7±0,4 mm.
ESTUDIO DE PLANTAS MEDICINALES EN LA AMAZONÍA PERUANA: UNA EVALUACIÓN DE OCHO MÉTODOS ETNOBOTÁNICOS
Authors: KVIST Lars Peter , ORÉ-BALBÍN Isabel Consuelo , GONZALES Andrea , LLAPAPASCA-SAMANIEGO Dedy Consuelo
Published: May 2017

Desde 1993 hasta 1998, se realizaron estudios de plantas medicinales en comunidades de la Reserva Nacional Pacaya-Samiria. Se aplicó ocho métodos para identificar especies que sirven a las poblaciones locales como medicinas con la finalidad de describir cómo estas las manejan y usan. En este estudio, se caracterizan y clasifican los ocho métodos usados investigando las fortalezas y debilidades de cada uno de estos. Asimismo, se identifican y discuten 11 objetivos principales para estudios de plantas medicinales y nueve parámetros adicionales útiles para medir ventajas y desventajas de los métodos. Se concluye que cada método contribuye de manera significativa a varios, pero nunca a todos los objetivos y que siempre hay factores que favorecen o dificultan los métodos, debido tanto a los recursos y medios disponiblespara el estudio como al entorno en que este se realiza. Así, la selección de métodos para el estudio de plantas medicinales deberá tener como base una cuidadosa precisión de objetivos y un análisis de las condiciones de la zona. En muchos casos, es necesario combinar varios métodos para cumplir con los objetivos definidos. Para ello, se aplican los métodos seleccionados en un orden lógico.
MICROZONIFICACIÓN DEL CULTIVO DE Myrciaria dubia HKB Mc Vaugh “CAMU CAMU” EN SUELOS ALUVIALES DE LA REGIÓN UCAYALI
Authors: LÓPEZ Antonio , RODRÍGUEZ-ACHUNG Fernando
Published: May 2017

El estudio tuvo como propósito elaborar una metodología de microzonificación de Myrciaria dubia HBK Mc Vaugh, «camu camu», en base a los requerimientosambientales del cultivo, en términos de clima, tipo de suelo, pendiente, condiciones del medio, accesibilidad y predisposición de la comunidad por el cultivo. Para ello, primero se procedió a establecer una escala de valoración a cada una de las variables ambientales y posteriormente se seleccionó la zona de trabajo en la localidad de San Francisco, sobre un área total de 100 ha.El trabajo de campo se realizó en el mes de diciembre del 2000, y para ello se utilizó el método de transectos. La fase de gabinete se realizó en el Centro de Información de la Amazonía Peruana, en la Unidad de Información Geográfica y Teledetección, del Instituto de Investigaciones de la Amazonía Peruana - IIAP, en el mes de febrero del 2001. Del trabajo de interpretación de los mapas temáticos de la microzonificación de San Francisco, se han establecido las siguientes conclusiones preliminares: Con relación a la variable textura de suelo, se presenta más de 90 ha de textura buena para el cultivo, con predominancia de las clases arcillosa, arcillo-limosa y franco-arcillolimosa. La textura arcilla franja sólo ocupa cerca de 10 ha. Respecto a la variable pendiente de terreno, se ha determinado que mayormente existen suelos con buena pendiente, entre 0 y 20 % (53 ha), y pocas áreas (11 ha) con pendiente mayor de 20 %, no apta para “camu camu”.Con relación a la altura de inundación, 33 y 41 ha, muestran muy bueno (menos de 1 m) y bueno (entre 1 y 2 m) nivel de inundación, respectivamente. Y con respecto a la profundidad efectiva del suelo se ha detectado 39 y 46 ha con niveles bueno (entre 21 y 30 cm) y regular (entre 11 a 20 cm), respectivamente. La evaluación de pH nos indica que la zona de estudio muestra entre 32 y 64 ha con rangos de pH adecuado (entre 6.1 y 7.3) y moderado (entre 5.1 y 6.0), para el establecimiento del cultivo en esa zona.Finalmente, recopilando toda la información se ha determinado que existen 86.5 ha con aptitud buena a moderada para la instalación del cultivo en la zona de San Francisco de Asís.
INFLUENCIA DE TRES DENSIDADES DE SIEMBRA EN EL CRECIMIENTO DE Piaractus brachypomus. “PACO” EN SEGUNDA FASE DE ALEVINAJE EN ESTANQUES SEMINATURALES
Authors: REBAZA-ALFARO Carmela , VILLAFANA E. , REBAZA-ALFARO Mariano , DEZA-TABOADA Sonia A.
Published: May 2017

El presente trabajo se realizó entre febrero y marzo 2000, en la Estación Experimental del Instituto de Investigaciones de la Amazonía Peruana (IIAP-Ucayali), localizado en el km 12.4 de la Carretera Federico Basadre, ciudad de Pucallpa, región Ucayali. El objetivo del presente estudio fue determinar la influencia de tres densidades de siembra en el crecimiento en peso, longitud y supervivencia de Piaractus brachypomus (Cuvier, 1818) “paco” en segunda fase de alevinaje; para lo cual se aplicó el diseño de bloques completos al azar con tres tratamientos: T1=10 alevinos m-2, T2=15 alevinos m-2 y T3=20 alevinos m-2, y tres repeticiones. Se sembró un total de 11 160 alevinos, con peso promedio inicial de 3.8g (coeficiente de variación 7.04% y desviación estándar: 0.44). Se suministró alimento balanceado particulado de 30% de nivel proteico, la tasa de alimentación fue el 10% de la biomasa, distribuyendo la ración en tres dosis diarias. Los resultados obtenidos después de 30 días de crianza para los tratamientos T1, T2 y T3 fueron: peso promedio final 21.94 g 20.79 g y 23.49 g; respectivamente; longitud promedio final: 10.12 cm, 10.0 cm, 10.34 cm; y porcentaje de supervivencia: 98.68%, 97.45% y 89.82%, respectivamente. No se observó diferencias significativas (P>0.05), entre los diferentes resultados en la segunda fase de alevinaje.