Manufacture of Portland Cement from Claystone of Nfayil Formation Middle Miocene, in Southern Desert of Iraq

The research aims to assess the claystone exposed in the Nfayil Formation (Middle Miocene) for Portland cement (P.C.) manufacturing based on mineralogy and geochemistry. The importance of the study is to avoid the miming of the agricultural soils that are mining now for the cement industry. Claystones of Nfayil Formation and the limestone of the Euphrates Formation were used to design the raw mixture as clay to limestone (1:3). The chemical composition (%) of the designed mixture was calculated using the Alligation Alternative Method (A.A.M.) as CaO (65.52), MgO (1.05), SiO2 (21.65), Al2O3 (7.43), Fe2O3 (2.62), Na2O3+K2O (1.52) and SO3 (0.26), which are suitable for P.C. The lime saturation factor (LSF = 92.8), silica saturation factor (SSF = 0.87), alumina ratio (AR = 2.8), silica ratio (SR = 2.16), and calcium to silica (CS = 3.04) of the planned mixture are all within the permissible range. A clinker was successfully manufactured as composed mainly of belite, alite, aluminate, and ferrite.

Experimental Investigation and Multi-Gene Genetic Programming Simulation of Portland Clinker Burnability

In this study, the effect of chemical composition of the raw material on the clinker burnability was studied by determination of free CaO (wt %) content of clinker. The burnability of two types of Portland clinker was investigated for silica modules of 2.3, 2.5 and 2.7 and lime saturation factor of 0.88–0.98. In addition, using the Multi-gene genetic programming (MGGP) model, the burnability of clinker was predicted. The results of MGGP model indicated that the performance of the model for predicting the amount of free CaO (wt %) was acceptable. Moreover, using MGGP, a promising correlation was introduced for accurately calculating the amount of free CaO (wt %). The performance of this correlation was compared with FL-Smidth, and it was established that the average errors of MGGP correlation and FL-Smidth equation were 2.95 and 7.45 %, respectively.

Chattering-Suppressed Sliding Mode Control for Flexible-Joint Robot Manipulators

In this paper, sliding mode tracking control and its chattering suppression method are investigated for flexible-joint robot manipulators with only state measurements of joint actuators. First, within the framework of singular perturbation theory, the control objective of the system is decoupled into two typical tracking aims of a slow subsystem and a fast subsystem. Then, considering lumped uncertainties (including dynamics uncertainties and external disturbances), a composite chattering-suppressed sliding mode controller is proposed, where a smooth-saturation-function-contained reaching law with adjustable saturation factor is designed to alleviate the inherent chattering phenomenon, and a radial basis function neural network (RBFNN)-based soft computing strategy is applied to avoid the high switching gain that leads to chattering amplification. Simultaneously, an efficient extended Kalman filter (EKF) with respect to a new state variable is presented to enable the closed-loop tracking control with neither position nor velocity measurements of links. In addition, an overall analysis on the asymptotic stability of the whole control system is given. Finally, numerical examples verify the superiority of the dynamic performance of the proposed control approach, which is well qualified to suppress the chattering and can effectively eliminate the undesirable effects of the lumped uncertainties with a smaller switching gain reduced by 80% in comparison to that in the controller without RBFNN. The computational efficiency of the proposed EKF increased by about 26%.

Simulation of the cement measurement based on the pulse DT neutron generator: A Monte Carlo study

The PGNAA system for the cement measurement was simulated based on Monte Carlo method. The sizes of the moderator and reflector for the 14 MeV DT neutron generator were optimized for fast and thermal neutron outputs. The DT neutron generator was simulated at the pulse mode, and the gamma-ray detector was set as LaBr3(Ce) scintillator. The characteristic peaks of the major elements (Ca, Si, Al, Fe) can be identified from the gamma-ray spectra which induced at the different time intervals of the neutron radiation. For the different thicknesses of the cement sample the ratios of the gamma-ray peaks were observed, and the result showed that when the thickness was between 20 to 30 cm, the ratios became stable. With the ratios, we can calculate the iron modulus, silica modulus and lime saturation factor.

Observer-based adaptive neural sliding mode trajectory tracking control for remotely operated vehicles with thruster constraints

For a class of remotely operated vehicle (ROV) systems with thruster constraints, immeasurable states, and unknown nonlinearities, the trajectory tracking control problem was discussed in this paper. The unknown nonlinear functions were approximated by radial basis function (RBF) neural networks. An adaptive state observer based on neural networks was designed and the immeasurable states were estimated. Considering the problem of thruster saturation constraints, an auxiliary system for saturation compensation was designed and a saturation factor was constructed by the auxiliary system state. By applying the backstepping design method, an adaptive neural sliding mode trajectory tracking controller was developed, in which the saturation factor is contained in adaptive laws. It was proved that the uniformly ultimately bounded (UUB) of trajectory tracking errors can be obtained. Finally, the effectiveness of the proposed trajectory tracking control approach was checked by simulations.

POROSITY AND PERMEABILITY PROPERTIES OF CONSOLIDATED ROCKS OF THE NORTHERN NEAR EDGE ZONE OF THE DNIEPER-DONETSK DEPRESSION

Paper concerned the researches of porosity and permeability properties of consolidated rocks (siltstones, poor-porous sandstones) of the northern near edge zone of the Dnieper-Donetsk depression. The purpose of the research was to study the petrophysical parameters of the consolidated reservoir rocks, as the basis of the integrated analysis of their physical properties. Such reservoir parameters as the open porosityfactor and void factor, permeability coefficient and residual water saturation factor were studied. Void structure of rocks with capillarimetric method was studied. The relationship of the density of rocks with their porosity was also studied. The porosity study was carried out in atmospheric and reservoir conditions. The bulk density of dry rock samples varies: for siltstones from 2232 kg/m3 to 2718 kg/m3 (mean 2573 kg/m3 ), for sandstones from 2425 kg/m3 to 2673 kg/m3 (mean 2555 kg/m3); water saturated rocks – for siltstones from 2430 to 2727 kg/m3 (mean 2622 kg/m3 ), for sandstones from 2482 kg/m3 to 2688 kg/m3 (mean 2599 kg/m3 ). An apparent specific matrix density varies: for siltstones from 2645 to 2740 kg/m3 (mean 2683 kg/m3 ), for sandstones from 2629 kg/m3 to 2730 kg/m3 (mean 2664 kg/m3). The open porosity coefficient of studied rocks, in a case they were saturated with the synthetic brine, varies: for siltstones from 0,008 to 0,074 (mean 0,034), for sandstones from 0,013 to 0,087 (mean 0,041), if samples were saturated with nitrogene (N2) then it varies: for siltstones from 0,013 to 0,076 (mean 0,040), for sandstones from 0,022 to 0.095 (mean 0.052). The effective porosity factor has following values: for siltstones 0,0003–0,0050 (mean 0,00026), for sandstones 0,0013–0,0293 (mean 0,0048). Analysis of reservoir conditions modeling revealed that porosity coefficient varies: for siltstones from 0,007 to 0,060 (mean 0,028), for consolidated sandstones from 0,011 to 0,081 (mean 0,037). Due to the closure of microcracks under rock loading reduced to reservoir conditions the porosity decreases in comparison with atmospheric conditions, which causes a relative decrease in the porosity coefficient for siltstones from 14 to 19,5 % (mean 17,0 %), for sandstones from 7,5 to 18.0 % (mean 10,5 %). Capillaryometric studies by centrifuging determined that the void space of the studied rocks has the following structure: for siltstones, the content of hypercapillary pores varies from 1 to 6 % (mean 3 %); the content of capillary pores – from 1 to 11 % (mean 5 %), the content of subcapillary pores – from 84 to 97 % (mean 92 %); for sandstones, the content of hypercapillary pores varies from 1 to 18 % (mean 4%); content of capillary pores – from 2 to 40 % (mean 10 %), the content of subcapillary pores – from 43 to 96 % (mean 86 %). According to the results of laboratory measurements of the permeability coefficient, this parameter varies: for siltstones from 0,002 fm2 to 1,981 fm2 (mean 0,279 fm2 ), for sandstones from 0,002 fm2 to 1,492 fm2 (mean 0,176 fm2 ). The correlation analysis has allowed to establish a series of empirical relationships between the reservoir parameters (density, porosity coefficient, permeability coefficient, effective porosity factor and residual water saturation factor). These relationships can be used in the data interpretation of geophysical studies of wells and in the modeling of the porosity and permeability properties of consolidated rocks of the northern near edge zone of the Dnieper-Donetsk depression.

Parametric Study of Matisaa Gray Rock as a Potential Clinker Material

This study aimed at evaluating Matisaa gray rock (MGR) for clinker production. MGR is naturally abundant in Matisaa, a rural area in Mwingi West District, Kitui county, Kenya. It is locally used as a gabion filler and other concrete structures with desirable physico-mechanical properties. This research employed a controlled experimental design to determine the clinker qualification of MGR. This was based on particle size analysis and raw meal moduli. The standard sieve tests and a Blaine meter were used in the determination of particle size while the raw meal moduli were determined from the respective cement oxides in MGR, which were determined using wavelength dispersive X-ray fluorescence (WDXRF) spectrometer. It was observed that 69.65% of the particle size composition of MGR was less than 90 . Out of this composition, 71.60% of the particle sizes were less than 45 , contributing to a specific surface area of 292.5 . The hydraulic modulus (2.05 – 2.61) and lime saturation factor (0.87 – 0.98) are quite desirable though the silica and alumina ratios are higher than the standard range due to the low proportions of and content. The sulfatisation modulus is also undesirable due to the high content of . Thus, without beneficiation, Matisaa gray rock would lead to the production of low-quality clinker. However, the general parametric comparison of Matisaa gray rock with Konza shows that it has the potential for utilization as a clinker raw material.

BACKGROUND OF MODERN TECHNIQUES FOR LABORATORY DETERMINATION OF THE ELASTICITY MODULUS OF COHESIVE SOILS AND THEIR DESIGN CHARACTERISTICS IN THE ROAD STRUCTURE (Part 2)

According to the results of laboratory stamping tests, samples (d = 150mm; H=180mm) of bulk with soil compaction having a water saturation factor Sr≥0,85 in the range of values of fluidity index – 0,5≤lℓ≤0,25 , it is concluded that it is possible to determine practically every sample, their modulus of deformability (Епр; Ед), the calculated critical resistance – Ro of soil and its maximum relative deformation λmax. The loading of the samples is carried out by a step load with a proportional (1.3 times) increased pressure, such as at each stage. During the test, the sample is not unloaded but is subject to conditional destruction, that is, a disproportionate increase in the deposits of the die. The duration of each load is three minutes. The graphs of parabolic functions of the type λ=aσb are plotted in logarithmic coordinates in the form of two segments straight on both sides of the fracture. The parameter of the degree of parabola “b” serves for preliminary estimation of the index of deformability: for the modulus of elasticity – b≈1,0 ± 0,2; for the modulus of deformation – b≈2,0 ± 0,5; for the yield modulus – b≥3.0. The work gives a comparison with similar indicators of deformability of other building and structural materials. The elastic modulus (Епр) has only a soil that meets the conditions of the standard seal ρdmax>ρdωρ і ω_o<ωρ; the modulus of deformation (Ед) has a soil when 0<lℓ<0,5, and the modulus of fluidity (Ет) has only a soil lℓ≥0,5. Natural structured soils are characterized by a modulus of structural strength (Est) in the range 0<lℓ< 0, which is determined by compression tests. In order to reduce soil consumption and increase productivity, it is proposed to consider the task of determining soil deformability indices for the calculation of road clothing as a contact and therefore reduce the height of soil samples from 180 mm to 40 mm Keywords: soil, soil engineering structure, compacted soil, design condition, elastic modulus, critical design resistance, maximum relative deformation.

Analysis of the efficiency of models of transition zones to determine oil-saturation factors and position of contact of hydrocarbons with water

The article is devoted to the usage of models of transition zones in the interpretation of geological and geophysical information. These models are graphs of the dependences of oil-saturation factors of the collectors on their height above the level with zero capillary pressure, taking into account the geological and geophysical parameter. These models are not recommended for estimating oilsaturation factors of collectors in the transition zone. The height of occurrence of the collector above the level of zero capillary pressure can be estimated from model of the transition zone that take into account the values of the coefficients of residual water saturation factor of the collectors, but only when the model of the transition zone is confirmed by data capillarimetry studies on the core.