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The fundamental properties of the Omani sarooj have been studied. Sarooj samples were collected from different sites to assess their pozzolanic activity. A laboratory testing program covering chemical and physical properties (consistency, setting times and compressive strength) were carried out. The effect of burning at different temperatures and durations on strength development was studied. The properties of sarooj were found to be dependent on the type of the clay, chemical composition, temperature and duration of burning. The controlling factors were viewed simultaneously in analyzing the test results. The optimum temperature that achieved the maximum compressive strength was found to be between 700°C and 800°C. At the optimum temperature, longer duration of burning produced shorter setting times.

This paper addresses the problem of voltage instability at which the power system reaches its maximum admissible load. A voltage collapse proximity indicator (VCPI) is derived and its performance is investigated. The VCPI is the ratio of the system equivalent impedance to the load equivalent impedance. In this paper, an algorithm for network equivalent impedance is proposed; it employs the PV-PQ sensitivity and "referencing" techniques to determine an equivalent impedance of a multi-machine multi-node power system. The validity and effectiveness of this method is demonstrated with the application of different network configurations ranging from the standard IEEE 14-bus to the realistic 116-bus Qatar power system.

Rutting has been a problem in Qatar's highway pavements since it began designing asphalt mixtures with the Marshall Method in the early 1990's. This paper describes specifications and rules-of-thumb which have been generated in the United States which may provide insight to Qatar's rutting problem and suggests modifications to mix design and construction procedures. The paper describes appropriate bitumen and aggregate specifications and discusses field procedures to implement mix design values produced in the laboratory. Maintaining 3-5% air voids in the mix is stressed at all times.

The accurate and efficient Galerkin's method was developed in the spectral domain for analyzing gap discontinuities in patch antenna array. Using new current distribution the problem is solved using full wave approach rather than quasi-static approximation. The new current distribution speeds up the convergence of the solution for obtaining the resonance frequency of the system with electric and magnetic walls at the planes of symmetry. The equivalent circuit of the gap is determined for different gap sizes.

Ultrasonic pulse-echo technique, tensile testing and thermal gravimetric analysis have been utilised to characterise and monitor the effect of y irradiation on the physicomechanical properties of low density polyethylene LDPE, grade FB 5005. The sonic modulus, elastic modulus, rupture stress and decomposition temperature exhibit a minimum value at 2 Mrad irradiated samples, whereas, toughness and rupture strain exhibit a maximum at the same irradiation dose. The changes in mechanical properties (rupture stress and toughness) correlate well with decomposition temperature and the change in the sonic modulus correlates as well with elastic modulus for the tested material. The results are discussed in terms of cross-linking. Below 2 Mrad the loss of crystallinity overrides the effect of cross-linking, whereas above 2 Mrad the cross-linking dominates.

This paper describes a microstrip optically controlled matching technique between microwave active devices with low impedance (less than 10 ohms) and a conventional 50 or 70 ohm communication system in the upper microwave and mm-wave frequencies. The bandwidth is 20 GHz. the maximum insertion loss is less than 1.5 dB and the reflection coefficient is less than-7 dB. The laser controlled terminal impedance's can be changed and adjusted by choosing the carriers lifetime of the semiconductor substrate and by changing the power and wavelength of the optical source.

This paper presents a simplified method for the calculation of thin-plate deflections. The method, which deals with uniformly loaded plates, uses the stiffness method to obtain plate deflection equations for specified boundary conditions. A case study was presented in order to demonstrate the use of the proposed method and to illustrate its capabilities. The results obtained were in close agreement with those obtained analytically and with those obtained using the finite element methods. Finally, a user-friendly program for plate deflection calculations based on the proposed method was developed using the mathematical package MATHCAD.

The drag coefficient (CD ) was determined for three different non-spherical particles (cubes, rectangles and cylinders) of different sizes falling in two different non-Newtonian fluids (glycerol and polymer - paraffin oil mixture) using the terminal velocity technique. The variation of the drag coefficient with the variation of non-spherical particle size was explained. Also the relation between CD and Reo (0.25-5) is graphically compared with those previously published in the literature for discs and cylinders with infinite length. Moreover some mathematical relations, previously published in the literature, are verified for the three tested non-spherical particles.

A new technique for image data compression based on fuzzy segmentation, classification and properties of sequency ordered Hadamard Transform (HT) is presented. Using a pyramidal data structure, an image is segmented into blocks of variable sizes. The size of each block is determined using a fuzzy procedure depending on the amount of information contained. Regions with low details are divided into blocks of variable size, while regions containing more information are successively segmented into smallest size of 4*4 blocks. Only a small number of more energetic components of HT are used for the coding of the uniform blocks, while a fuzzy edge oriented classifier is designed for the coding of the high-detail blocks. The classifier employs several prototype edge patterns in HT blocks and the fuzzy techniques for recognition of the direction of edges. The low-detail regions are coded with very low bit rate on the expense of small reduction in the visual quality of images, while the coding process for high-detail regions results in an acceptable image quality. Decoded images of high quality are obtained for encoding rates of 1 bit per pixel.

This paper presents a design optimization method for concrete slab forms. This procedure was formulated to provide a safe slab form design with minimum cost. The proposed method considers in its design process the cost of each slab form component (sheathing, joist, stringer, and steel shore) as well as all available combinations of slab form components. A case study is presented to show the capabilities of the proposed method and also to illustrate its potential cost savings over the slab form design practice in the State of Qatar. The study showed that the proposed design method has a substantial cost saving over the design practice currently used in the State of Qatar.

Many brands of bottled water are being produced in the Middle East including the Gulf Cooperation Council (GCC) countries. Over fourteen brands of bottled water could be found in the market of Doha. Use of bottled water has kept on increasing in this region. Reasons for the increase in use of bottled water for drinking have been discussed. The raw water source for the bottled water is groundwater. Most of the manufacturers of the bottled water claim bottled water as "Natural Mineral Water" which is contrary to the definition suggested by the International Bottled Water Association of Washington D.C. In fact there is no such thing as "mineral water" and the term is a misnomer. Samples of various brands of bottled water available in Doha and municipal water were collected during 1993 and 1994 for physical, chemical, and bacteriological analysis. All the samples were found potable and safe for drinking and conform to various drinking water standards. The physical and chemical composition of bottled water varies with time but the concentration of constituents printed on the labels of bottles is always the same. It may be preferable to print the range of concentration on the labels rather than a single value. Moreover the analysis should be monitored and certified by a competent authority, and should be displayed on the label.

An Artificial Neural Network (ANN) model based on the back-propagation technique is trained with a number of variables from experimentally established relative permeability curves. The reservoir core input data covers an extensive range of porosities and permeabilities from different sandstone lithologies having diverse wettabilities. The trained model is then tested with only a couple of input variables such as the initial connate water saturation, S,»c and the residual oil saturation. So, . The developed model outputs, or the predictions define the relative permeability end-points and the intersection point to quantify the wettability and the shape of the relative permeability curves. A number of correlations based on empirical models and network models exist to predict the relative permeability curves and the wettability of oil bearing sandstone formations from the initial oil and water. Calculations from the ANN model were then compared with values calculated from other models currently in wide spread use.

This paper is concerned with the performance characteristics of thermostone as a building material, and their comparison with those of hollow concrete blocks. Carrier Advanced Load Program (E20-II) was used to estimate the annual cooling load of a typical residential Qatari house. A number of combinations of walls and roofs for the house have been used, and the annual electrical energy to air-condition the model house for these combinations are estimated. Comparison of the results revealed that a house whose walls are built from thermostone blocks would consume 25 % to 30 % less electrical energy than one whose walls are built from hollow concrete blocks. An economic analysis has been performed for these combinations of roofs and walls. The results show that building with thermostone blocks can cut the annual cost of electricity by 28% to 34% as compared to building with hollow concrete blocks.

A self-organizing multisensor fusion algorithm to classify the inputs (data or images) into classes (targets, backgrounds) is presented. The algorithm forms clusters and is trained without supervision. The clustering is done on the basis of the statistical properties of the set of inputs. The algorithm is a self-organizing algorithm, since it has the ability to form and adjust the number of clusters without being given the correct number of clusters. This algorithm implements a clustering algorithm that is very similar to the simple sequential leader clustering algorithm and the Carpenter/Grossberg net algorithm (CGNA). The algorithm differs from CGNA in that (1) the data inputs and data pointers may take on real values, (2) it features an adaptive mechanism for selecting the number of clusters, and (3) it features an adaptive threshold. The algorithm does not require the number of classes been known apriori. The problem of threshold selection is considered and the convergence of the algorithm is shown. An example is given to show the application of the algorithm for multisensor fusion for classifying targets and backgrounds, and the results of using this algorithm is compared to the results of using K-nearest neighbor algorithm.

In this paper modeling, selection and optimization of fuzzy rules for multivariable feedback process control and decision making systems are developed and discussed. A general model for multivariable fuzzy rules is derived and sets of fuzzy parameters are assigned to the consequents of each rule. A genetic algorithm is used to optimize these parameters. A genetic algorithm search technique is also developed for the selection of the sub-set of appropriate rules from a larger theoretically possible set. The procedure is implemented on a multivariable dynamic model and results of extensive simulation studies are presented to demonstrate a satisfactory performance of the proposed approach

This paper introduces an improved three dimensional finite-element (3D-FE) computational approach for magnetostatic field problems using unconstrained magnetic vector potential (MVP) formulation in conjunction with hexahedral type elements. It was found that the use of first order or second order hexahedral type element in the FE formulation eliminates the sensitivity of the FE computational results to grid geometries and elemental shape ill-conditioning associated with first order tetrahedral type elements. The method is shown to be computationally economical and is highly recommended for large scale global type 3D magnetostatic field computations in electrical devices.

The Scaled-Variable-Rcduced-Coordinatc (SVRC) method with a proposed set of mixing rules are applied to calculate the liquid density of several system of liquid mixture and satisfactory results are obtained. The ability and accuracy of the proposed method arc compared with other widely used method such as Hankinson-Thomson method and Spencer and Danncr modification of Rackett method. The results of SVRC method with the proposed mixing rule and comparison with other methods indicate that the proposed model is as good as the best available methods.

The American Association of State Highway and Transportation Officials (AASHTO) uses resilient modulus values as the load-carrying capacity parameter for all pavement materials. However, the maximum sample diameter in standard resilient modulus test specifications is only 150 mm (6 inches). With that limitation, large-sized aggregates can not be tested at their full gradation because if top-size-to-sample diameter ratios exceed 1:5, arching effects occur during sample preparation which adversely affect the results. Thus, little work has been performed on the resilient modulus of large top sized aggregates. In this study, 305 mm (12 inch) diameter samples of two different aggregates were tested for resilient modulus. The materials were tested at top sizes of 63 mm (2.5 inches), 38 mm (1.5 inches), and 19 mm (0.75 inches). Results indicate that the tests bec~me less repeatable as top size increases, and that resilient modulus does not increase as top size increases. The second result is contrary to the conventional belief that load carrying capacity of aggregates increases with increasing top size.

Experimentally measured kinematic viscosities are reported for benzene, cyclohexane and n-heptane saturated with hydrogen, nitrogen and carbon dioxide. A Zeitfuchs cross-arm viscometer suspended in a unique design pressure cell was used to contain the viscometer at pressures from 200 to 1000 psia. Temperatures ranged from 75 to 200°F. Absolute viscosities were computed by use of an equation of state and a liquid density prediction method.

1976 Diffic and Hellman introduced the concept of public-key cryptography and in 1978, McEliece introduced the first public-key cryptosystem based on error correcting codes. Since that time, several methods have been proposed to use error correcting codes for cryptography either directly or indirectly. In this work we propose the use of cascaded codes in McEliece algorithm where cascading here means that one code is used after the other. Two or more codes are used in cascade to get high error correcting capabilities even with moderate length codes. This makes the system more useful over noisy channels. The structure of cascaded codes is in itself a good way to secure the data. Binary block codes are only considered in this work although other types of codes can be used. We discuss two different encryption schemes where normal and Tensor products of matrices are used to form the codes. The proposed schemes are more adequate for block encryption. Decoding is also performed in cascade to make use of the existing fast decoding algorithms available for each of the used codes. Therefore, the decryption process will be fast too compared with other schemes based on number theory. The selection of proper code parameters is discussed and the probability of correct recovery of transmitted messages is also found.

The paper presents a method for estimating long-term deflections of reinforced concrete beams by considering creep and shrinkage effects separately. Based on equilibrium and compatibility conditions a method is developed for investigating the properties of a cracked transformed section under sustained load. The concept of effective moment of inertia is extended to predict initial-plus-creep deflections. Long-term deflections computed by the proposed method are compared with the experimental results available in the literature and with the values obtained by the ACI Code method. This comparison shows that for beams having span/thickness ratio greater than 25, the ACI Code method underestimates long-term deflections while the proposed method gives a better estimate with computed to measured deflections ratio equal to 1.0.

Environmental conditions in the State of Qatar together with lack of good-quality aggregates seem to severely reduce the service lives of constructed pavements. The current practice of road construction agencies in Qatar is to utilize Marshall method of mix design to arrive at the best combination of aggregates, commonly crushed local limestone or imported Gabbro as coarse and fine aggregates and a mineral filler, and the 60/70 pen. grade bitumen. Little effort was undertaken to investigate the possibility of blending the local limestone and imported Gabbro aggregates and/or utilizing a harder bitumen grade, such as the 40/50 pen., to improve the properties of produced asphalt concrete mixtures. The main objective of this study is to assess the effect(s) of using a blend of 50 % Gabbro, 50% limestone as an aggregate on the performance of the respective bituminous concrete mixtures utilizing the 40/50 and 60/70 pen. grade asphalt cements as binders, respectively. Results of the study indicate that a better Marshall stability could be obtained by blending limestone and Gabbro aggregates. However, the 40/50 pen. concrete mixtures did not exhibit superior qualities to those of the commonly used 60/70 pen. Asphalt concrete mixtures utilizing Gabbro aggregates alone showed better mix density and were less affected by water soaking.

Most of organic compounds are partially miscible in water and due to their solubility criteria split into two liquid phases. So design of equipments that separate two liquid phase systems differ from one liquid phase system equipments. A mathematical model and a computer program have been developed to simulate three-phase distillation columns. The proposed procedure is based on linearization of equations and solving them by Newton-Raphson method. Average liquid compositions are chosen as independent variables and temperature, vapor compositions and two liquid phase compositions are obtained by three-phase bubble point calculations on each tray. For predicting thermodynamic properties, equation of state is used

A method is described for the extraction of capacitor values for switched capacitor (SC) networks which compensate for the effect of finite amplifier bandwidth in the design of SC networks using optimization. The finite bandwidths of the amplifier distort the response of the network from the required response. It is shown that by readjusting the poles and zeros of the transfer function, the required response can be accurately restored. The values of capacitances are extracted by running a number of parallel local optimizations, each starting from different random initial conditions, on a network of transputers. This method removes the possibility of an optimization being trapped in a local minimum and ensures the stability of the design network.

Hamming Neural networks are employed for cursive text character separation and recognition. The digitized image of the scanned text is first enhanced by applying simple contrast stretching algorithm. Image registration is then performed to eliminate the white margins. Lines are separated by rows of white pixels and the morphological components identified. The projection method in conjunction with histogram analysis is used to estimate the width of each character in a word. The word is approximately decomposed into its constituent characters. The Hamming net is used to identify thus separated characters, while supposing the included portions of the adjacent characters as noise. The property of the trained Hamming net, i.e., the associative feature for detecting the best matched patterns from the prototype in a mean square sense, is the basis for constructing the recognition algorithm. Illustrative examples are presented and it is shown that the proposed approach is fast and efficient to provide an on-line separation and classification system for cursive texts such as Persian (Farsi), Arabic, Urdu and English script.

Space imageries with their low costs and availability for every one, provide a good opportunity for topographic mapping of unmapped or poorly mapped areas around the world particularly in the developing countries. The French SPOT Imaging system is the first space orbiting satellite with stereoscopic capability. Panchromatic stereoscopic pairs with variable base to height ratios are available and can be arranged for any part on the earth's surface. In this investigation, three dimensional coordinates are extracted from SPOT stereoscopic images using two analytical photogrammetric methods. In the first method, a stereoscopic model is formed by using the analytical relative orientation technique. Three dimensional model coordinates, then, were fitted into ground coordinates using a number of mathematical models of coordinates transformation. The second method used is the space intersection, where three dimensional ground coordinates of the intersection point of each two similar rays are computed. This procedure, normally, follows the application of the space resection, where the exterior orientation elements for the two stereoscopic images have to be determined. To assess the accuracy of the extracted three dimensional coordinates, residuals and their root mean square values in a number of check points were computed and analyzed.

This paper is concerned with the calculation of the moments exerted by a viscous fluid on the walls of a cylinder that is spinning about its axis and coning about an axis that passes through its center of mass. For small coning angles and/or coning frequencies, these moments are estimated by solving the linearized Navier-Stokes equations. Solving the linearized Navier-Stokes equations is computationally expensive. Fortunately, when using the control volume approach to calculate these moments, these moments depend essentially on the axial velocity, and the linearized equations describing the deviation of the fluid motion from solid body rotation can be reduced to a single sixth-order partial differential equation governing the axial velocity. This single equation is solved by expanding the axial velocity in a triple series made of Fourier functions in the azimuthal direction and Chebyshev polynomials in the radial and axial directions. For linear analysis, only the fundamental component in the azimuthal direction is needed for the evaluation of moments and the triple series is reduced to a double Chebyshev expansion in the radial and axial directions thereby reducing the three-dimensional problem into a two-dimensional one. The results obtained by Chebyshev expansion show good agreement with those obtained by using eigenfunction expansion.

The catalytic oxidation of petroleum waxy distillate (boiling range 400 - 440°C at 760 nun Hg) using KMn04 catalyst and air was studied in a batch reactor. The effect of reaction temperature (100-160°C), air flow rate (0.5-1.5 L/min per 100 g wax) and catalyst weight (0.4-0.6 % by wt. of wax) on the acid number of the reaction mixture was studied. Monobasic acids with an average number of carbon atoms/molecule of C^.C^ could be obtained. The surface active properties of the soap solutions made from the obtained fatty acids (after separation from the reaction mixture, followed by purification) confirm that this soap can be successfully used as household soap. This will help to reduce the consumption of edible oils for soap making.

Three flammable binary systems were studied for flash point as a function of liquid mixture composition: 1) decane/dodecane, 2) 0-xylene/cyclohexanol, and 3) 2-propanol/water. The vapor composition was estimated at each liquid mixture for which a flash point was obtained and these results were compared to the mixing rule proposed by Le Chatelier. This comparison shows that excellent agreement is obtained where the vapor composition can be accurately predicted, such as the nearly ideal case of system 1, but that for systems 2 and 3, where the composition calculations were made from the UNIFAC model and the Wilson model respectively, the agreement was not as good.

Eighteen rectangular singly reinforced high-strength concrete beams without web reinforcement were tested in combined shear and flexure. The main variables were the longitudinal steel reinforcement ratio and the shear-span to effective depth ratio. The uniaxial compressive strength of concrete was about 93 MPa (13,500 psi). The experimental shear capacities were compared with the shear capacities predicted by different empirical equations presented in literatures. Two empirical equations have been proposed to better predict the shear capacity of reinforced high-strength concrete beams without stirrups.

The problem of fully developed, laminar, steady, forced convection heat transfer in an electrically conducting fluid flowing in an electrically insulated, horizontal, circular pipe (whose wall is subjected to a uniform heat flux) in a vertical uniform transverse magnetic field has been considered numerically. The central difference scheme is employed in the analysis. For high Hartmann numbers (100 •& M •& 500), the refinement of the mesh in the radial direction is necessary in order to handle the effect of the Hartmann boundary layer. To have a convergent solution, under-relaxation is needed for high M. A considerable number of results for MFM forced convection are obtained. All the results (i.e. velocity and temperature distributions and heat transfer), in general, are in a good agreement with the previous work.

This paper considers adaptive position control of a permanent magnet (PM) stepper motor using exact linearization via static state-feedback. Physical outputs are chosen in such a way that the resulting closed-loop system is linearized and decoupled. The objective of the adaptive controller for a PM stepper motor is to achieve output tracking between the motor outputs and prescribed reference signals in presence of parameter uncertainties. This will be achieved by incorporating a parameter identification scheme in the nonlinear state-feedback control law. Simulation results are presented and discussed.

The tensile properties of nine different grades of low density polyethylene were measured, and the relationships resulting from the combination of different pairs of properties were analyzed. It was found that some properties correlate well together, with a correlation coefficient better than 0.90. Such correlations will be useful in easily predicting the tensile properties of low density polyethylene. The FB grades exhibited the highest ultimate tensile strength and offset yield strength while their ductility and toughness were lowest when compared with the other grades. The MG12 and FD grades were of highest modulus of elasticity. The variation in a given property, for the nine grades, ranged from 40 % for the ultimate tensile strength, up to 2.6 fold for the strain at break.

This case study represents a typical example of surveying and assessing traffic characteristics along a local ring road in Doha City. Expected impacts of possible short-term (5-year) traffic management schemes for two main intersections were evaluated utilizing available PC software programs. Results indicate variations in traffic characteristics among different directions, sections and segments of the studied ring road. An optimum short-term management scheme was chosen for each of the two main intersections under study and the corresponding queuing delays and volume-to-capacity ratios were assessed. The study recommends more comprehensive traffic surveys in the future that should be undertaken as an integral part of a traffic master plan for Doha City. This master plan is a must for taking sound decisions concerning needed traffic management schemes.

This study is concerned with the problem of unsteady interphase diffusion for multicomponent dilute solutions. An integral technique, based on an approximate boundary-layer approach is used. Results are in good agreement with the exact solution available for the particular case of binary mixtures.

Composite, disc-like aluminum reinforced graphite electrodes were prepared, and an integrated parametric analysis has been performed to investigate the effect of some processing parameters on the electrical conductivity of the prepared samples. The presence of aluminum improved the electrical conductivity of graphite electrodes. A maximum in the electrical conductivity is always observed for samples baked at 600°C and/or for 1.5 hours baking time. The conductivity also increases with the compacting pressure. The novel idea of reinforcing graphite with metallic particulate fillers works well in improving the transport properties of graphite electrodes.

Twenty high-strength plain concrete deep beams were tested under torsion. The variables were concrete strength and depth/width (aspect) ratio. Concrete strengths of 51.01, 58.53, 76.60 and 83.66 MPa and depth/width (aspect) ratios varying from 1 to 5 were used. The tested beams failed suddenly and violently along a smooth surface. The crack inclinations on the beam surfaces were influenced by the concrete strength and aspect ratio. Test results show that by increasing the concrete strength or by reducing the aspect ratio, the torsional capacity and the beam stiffness increases while the angle of twist decreases. A modification has been suggested to the strength equation of the ACI Code 318-89 for normal-strength concrete shallow beams under torsion to include the effect of high-strength concrete for deep beams. The proposed equation gave .a. good estimate of the experimental torsional strength.

Spreadsheets are becoming increasingly popular, as a useful tool, for making process engineering calculations. This paper shows the use of spreadsheets for computations of an unsteady state process described by ordinary differential equations. The model equations are numerically solved using the fourth order Runge-Kutta method implemented on a spreadsheet. The spreadsheet implementation of this method demonstrates the possibility and usefulness of spreadsheets for their application in the simulation of dynamic processes.

The effects of harsh field environmental exposure conditions on compressive, tensile and flexural strengths and durability aspects of concrete such as chloride penetration, sulphate attack and carbonation were investigated for a period of 240 days. The environmental variables studied were control laboratory condition at Qatar University, chloride and sulphate rich ground field condition (Zone A) located 10 Km from Doha City, and below the water table field condition (Zone B) exist at the same selected site. The results indicate that concrete specimens kept at ground field condition (Zone A) exhibit lower compressive, tensile and flexural strength values than both the control laboratory and the below water table field conditions. The loss in strength has been attributed to the cessation of hydration due to drying of the concrete. The strength values of control laboratory condition and below water table field condition (Zone B) were marginally comparable in spite of the considerable difference of chloride, sulphate and carbonation values.

Use of a quadratic mixing rule in the Parameters from Group Contributions Equation of State increases the range of compounds for which vapor-liquid equilibrium behavior can be satisfactorily correlated. This is demonstrated by correlation of vapor-liquid equilibrium for several binary mixtures containing at least one polar component.

This paper summarizes an experimental program for developing a pilot procedure to check and predict field densities of compacted soils using static cone penetration tests. Three sandy soils were tested. The testing program included both laboratory and field tests. On the basis of laboratory tests, density prediction curves were developed while field results were used to find a correlation to predict densities on the basis of measured penetration resistances. The results are rather encouraging and promising. It is anticipated that the presented methodology would be very effective for compaction quality control in large areas of sandy soils because it is fast, simple and causes minimum disturbance to the compacted soil.

Resonance of the motion of two fluids inside a cylinder that spins about its axis and rotates (cones) about an axis that passes through its center of mass is known to occur for low-viscosity fluids (high Reynolds number flows) at critical geometric parameters and coning frequencies. In this paper the motion of two inviscid fluids inside a spinning and coning cylinder is analyzed by the method of separation of variables for small coning frequencies and/or coning angles. The analytical solution of the inviscid flow equations provides a criterion in the form of a transcendental equation that governs the behavior of the parameters that cause resonance. The transcendental equation was solved numerically by Newton-Raphson's iteration and the results are in good agreement with those obtained for two viscous fluids.