Pseudo Element Research Articles

Comprehensive investigation of almond shells pyrolysis using advance predictive models

This research focused on comprehensive characterization and assessment of almond shells pyrolysis for bioenergy potential through thermogravimetric analysis from ambient temperature to 900 °C at different heating rates of 10, 15, and 20 °C/min in inert environment. Iso-conversional model-free methods like Friedman, Ozawa-Flynn-Wall (OFW), and Kissinger-Akahira-Sunose (KAS) were used for kinetic analysis. Average activation energies (Ea) evaluated using Friedman, OFW, and KAS methods were 198.45 kJ mol−1, 204.43 kJ mol−1, and 204.97 kJ mol−1, respectively. The evaluation of thermodynamic parameters, including ΔH‡, ΔG‡, and ΔS‡, was also assessed. The average values of ΔH‡, ΔG‡, and ΔS‡, were found to be 199.4 kJ mol−1, 172.17 kJ mol−1 and 42.60 kJ mol−1 respectively. The reaction mechanism was obtained from combined kinetics. A high R2 value of 0.9933 demonstrates strong agreement between the combined kinetic analysis results and the experimental data. The distribution activation energy model was assessed employing four pseudo elements identified as PC1, PC2, PC3, and PC4. Artificial Neural Network (ANN) and Boosting regression trees (BRT) were used for the prediction of Ea of almond shells pyrolysis. The detailed understanding of thermokinetics and creating customized predictive and innovative modelling techniques like ANN and BRT sets a new benchmark for developing customized models for thermochemical conversion of varieties of almond shells.

Dependability of water disposal systems of major cities

The Aim of the paper is to develop an analytical procedure for calculating the dependability indicator of a specific tree-like transporting network, i.e., the water disposal system of a major city.Methods. It is suggested using the relative volume of sewage water released from a sewage system into the environment as the result of the failure of the former’s components as the measure of dependability. This paper presents a simple and convenient method for calculating such volume. The method is based on the representation of a tree-like sewage network as a combination of Y fragments referred to as structural elements. Every such element is formally replaced with its pseudo equivalent with a failure rate calculated assuming that the volumes of untreated waste water released by actual and fictitious elements are equal. A consistent application of this approach reduces the problem of estimation of the volume of released waste water to elementary subproblems that are solved using probability methods.Results. The problem of identifying the operational dependability indicator comes down to a recurrent stepwise procedure for equalization of Y fragments of the network, at each step of which the calculation data from the preceding step are used as the input data. Each such step, starting from the entry network, leads to another (virtual) network, for which the procedure repeats. The equalization process ends when the original network is represented by only one pseudo element, for which the dependability indicator is defined in an elementary way.Conclusion. The authors developed a convenient method for calculating the operational dependability indicator of a tree-like sewer network of a major city. Some practical problems are referred to that can be solved using the proposed method. Future lines of research in the domain were identified.

Sensitivity Enhancement of Pre-Capillary Chelation Method for the Separation of Metal Ions: Experimental and DFT Study

Background: Heavy metal toxicity has proven to be a major threat and there are several health risks associated with it. The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning. They sometimes act as a pseudo element of the body while at certain times they may even interfere with metabolic processes. Sensitivity enhancement and selective pre-capillary chelation and separation method was developed for the simultaneous determination of metal ions by capillary zone electrophoresis (CZE) with UV light as a detector. Method: This method was based on chelation of metal ions such as nickel(II), cobalt(II), lead(II) and zinc(II) with 2.0 mM Ammonium Morpholine-4-Carbodithioate (AMC) at pH 7.2 prior to analysis in 2.0 mM of phosphate buffer. Results: Different optimal conditions such as effect of pH, concentration of AMC, applied voltage, nature of the buffer solution and excipient ions were investigated to enhance the sensitivity of the method. Conclusion: The developed method separate nickel(II), cobalt(II), lead(II) & zinc(II) in less than 5 min with good reproducibility and recoveries ranging from 93.50 to 100.00 % in agricultural materials. Furthermore, the interaction and Density Functional Theory (DFT) based studies reveal that the metal ions form relatively stable complexes with AMC and follows the experimental trend performed with CZE.

Transient liquid phase bonding of cast Al0.3CoCrFeNi high-entropy alloy using Ni/Zr/Ni laminated foils

Cast Al0.3CoCrFeNi high-entropy alloy was successfully bonded by Ni/Zr/Ni laminated foils using a transient liquid phase bonding method. When the bonding temperature exceeded 1140 °C, the active Zr atoms from Zr-Ni liquid alloy diffused into the grain boundaries and interdendritic region of the Al0.3CoCrFeNi base material and triggered a eutectic reaction with Al0.3CoCrFeNi in this region, which acted as a pseudo element. The formed liquid phase accelerated the dissolution of cast Al0.3CoCrFeNi base metal and a composite microstructure with the soft FCC Al0.3CoCrFeNi phase embedded into the brittle Ni7Zr2 intermetallic compound formed in the seam upon cooling. The mechanical performance of the joint was significantly affected by the bonding parameters. When the bonding was carried out at 1160 °C for 30 min, a joint with balanced ductility (face-centered cubic phase) and strength (Ni7Zr2) was obtained. The maximum shear strength of approximately 247 MPa was obtained. This value was approximately six times higher than that of the joint bonded at 1120 °C. The joints fractured in ductile interlamellar fracture mode.

Toxicity, mechanism and health effects of some heavy metals.

Heavy metal toxicity has proven to be a major threat and there are several health risks associated with it. The toxic effects of these metals, even though they do not have any biological role, remain present in some or the other form harmful for the human body and its proper functioning. They sometimes act as a pseudo element of the body while at certain times they may even interfere with metabolic processes. Few metals, such as aluminium, can be removed through elimination activities, while some metals get accumulated in the body and food chain, exhibiting a chronic nature. Various public health measures have been undertaken to control, prevent and treat metal toxicity occurring at various levels, such as occupational exposure, accidents and environmental factors. Metal toxicity depends upon the absorbed dose, the route of exposure and duration of exposure, i.e. acute or chronic. This can lead to various disorders and can also result in excessive damage due to oxidative stress induced by free radical formation. This review gives details about some heavy metals and their toxicity mechanisms, along with their health effects.

Triaxial Woven Fabric (TWF) Composites with Open Holes (Part I): Finite Element Models for Analysis

Two finite element models (Superelement 1 and Superelement 2)are developed for prediction of mechanical behavior of triaxial woven fabric (TWF) composites with open holes. Superelement 1 is a 15-node superelement constructed of six identical 8-node 3-D isoparametric elements and three identical 4-node 2-D isoparametric laminate elements. Superelement 2 is similar to the first element except that this element takes into account the geometric and material properties of the twisted yarns. The assembly is done by the pseudo element technique suggested herein and the static condensation procedure. The availability of these elements allows for the analysis of complex structures of the triaxial fabric with open holes. Superelement 1 can be used for the vibration analysis with some economy of computer space and time. Superelement 2 can be used for detailed stress analysis and for strength prediction. Although these two elements are developed for the TWF composites with open holes, they can be applicable for analytical models for other materials and structures made of other types of textile composites.

Two accelerating techniques for 3D reconstruction

Automatic reconstruction of 3D objects from 2D orthographic views has been a major research issue in CAD/CAM. In this paper, two accelerating techniques to improve the efficiency of reconstruction are presented. First, some pseudo elements are removed by depth and topology information as soon as the wire-frame is constructed, which reduces the searching space. Second, the proposed algorithm does not establish all possible surfaces in the process of generating 3D faces. The surfaces and edge loops are generated by using the relationship between the boundaries of 3D faces and their projections. This avoids the growth in combinational complexity of previous methods that have to check all possible pairs of 3D candidate edges.

Reconstruction of quadric surface solids from three-view engineering drawings

In this paper, a robust and systematic scheme that automatically interprets three-view engineering drawings as quadric surface mechanical parts is addressed. Initially a three-dimensional wire-frame, with no face information in it, is reconstructed from the three orthographic projections. Next, all candidate faces are found within the wire-frame, using a minimum-internal-angle searching method. Then, pseudo elements that could be generated from back-projection are detected and deleted using a decision-chaining method. Finally, all true faces are assembled to form an oriented three-dimensional object. Face orientation consistency is ensured using the Moebius rule. The entire algorithm has been implemented in C on a UNIX system and experimental results are shown.

Pseudo element method (PEM) for solving matrix with elementary operation and its application

A pseudo element method (PEM) is presented in this paper for solving the matrix with elementary operation arising from the static analysis of cyclic symmetric structures. Three kinds of pseudo elements are devised to consider the transformed terms in the stiffness matrix during the elementary operation. Thus, the overall stiffness matrix may not be assembled by using the frontal solution technique. This can need relatively small computer memory and relatively short CPU time. The centrifugal displacements and stresses of a ring structure are calculated by introducing the cyclic symmetric conditions. The calculated results show, in comparison with theoretical ones, that the present method and its program are effective and can be conveniently used on a personal computer. At the end of this paper, the centrifugal fillet stresses of left-handed helical gear structures with different rim and web sizes are evaluated.

Finite element crack growth algorithm for dynamic fracture

A new finite element crack growth algorithm has been developed to simulate dynamic fracture. In this algorithm, pseudo elements with very high initial density are placed below the crack plane and the density is reduced to zero in a gradual manner as the crack passes the element. A number of linear elastic and elasto-viscoplastic problems have been carried out to test the new algorithm. The results are compared with some of the existing crack growth models.