Inherently Safer Analysis of the Attainable Region Process for the Adiabatic Oxidation of Sulfur Dioxide

The attainable region (AR) method is used to obtain the optimal design and operating conditions for the adiabatic oxidation of sulfur dioxide to sulfur trioxide. The optimum process layout for this exothermic, catalytic, reversible reaction is a complex interconnection of reactors that achieves a conversion in excess of the equilibrium value for a single adiabatic reactor. The complex design obtained from the AR method is technically and economically superior to a single adiabatic reactor, but it is inferior from a safety perspective as a result of its complex interconnections and its high preheat temperature. The strategies of inherently safer design (minimize, substitute, moderate, and simplify) have been applied to the complex design to compare it with conventional adiabatic reactor designs

Effect of the Sliding of Stacked Live Loads on the Seismic Response of Structures

Dynamic interaction between sliding live loads and the structure they act on is significant in the seismic analysis and design of the structure. The problem becomes more complex when the live loads are in the form of stacks. This paper presents a numerical model to simulate the dynamic interaction between a primary structure (PS) and a set of stacked bodies lying on it. Individual bodies in the stack were termed as secondary bodies (SBs) in this study. The lowest SB in the stack interacts with the structure through friction. Similar frictional forces also exist between different levels of the stack. This numerical model was verified with a Finite Element model. A parametric study was performed on the seismic response by varying the dynamic properties of the structure and SBs. The energy dissipation is found to be significant due to sliding within the stack. A novel methodology is proposed to calculate a modified structural period (Tnew) of the structure to use in its design. It was found that the Tnew varies significantly with the structural period, mass ratios, and coefficients of friction. Finally, design equations are proposed to calculate the Tnew . Two Indian seismic hazard levels were considered for this study

Finite Element Analysis Of Modified Conebolt Under Static And Dynamic Loadings

Axisymmetric finite element models are developed to simulate static pull test and dynamic drop test of MCB33 (modified conebolt with full dedonding) using ABAQUS. Results from the numerical models are in reasonable agreement with the test results. A parametric study is performed considering various variables (i.e. friction, cone angle, material strength, etc.) to analyze the performance of MCB33. The results demonstrate that friction between the steel and resin, cone angle, and the Poisson’s ratio of the resin affect the static and dynamic behaviors of the rockbolt. These parameters can be modified to improve the current design and enhance the overall performance of the rockbolt

Effects Of Unit-Cell Boundary Type On The Electromechanical Properties Of Randomly Distributed Multifunctional Composite Structures

The unit-cell composition of three-dimensional finite element models for 3-0 and 3-1 type polymer (PVDF) - ceramic (BaTiO3) and ceramic (PZT-7A) - ceramic (BaTiO3) structures are compared to determine the effects of fiber interaction at the surface of the unit-cell on the effective elastic, piezoelectric and dielectric properties of the multifunctional composite systems. The first unit-cell type examined has enclosed fibers that are completely contained within its boundaries, the second type has fibers that are contained within the sides of the unit-cell but can be cut at the top and bottom surfaces, and the third type has fibers that can be cut on the top, bottom and side surfaces of the unit-cell. All cut fibers are matched on opposing surfaces for continuity. Randomly distributed and aligned circular fibers, randomly distributed and randomly oriented circular fibers, and one central enclosed fiber with varying volume fractions and aspect ratios are compared with these three unit-cell structures. Results show that fiber models display greater or equal values of C"" when compared to aligned or randomly oriented fibers for all cases except aspect ratio 1 polymer-ceramic structures. The third type of unit-cell shows the highest e""values for single, aligned and randomly oriented fiber structures, except for the aspect ratio 10 polymerceramic case where the second type of unit-cell has greater results for aligned and single fibers. Finally, it can generally be seen that randomly oriented fibers have smaller values than similar aligned and single fiber structures with the exception being C"" of the ceramic-ceramic structures

Genome editing in poultry - opportunities and impacts

Poultry products (meat and eggs) are a major source of animal protein on which the world is increasingly reliant to feed a rapidly growing population. Improved breeds and advances in farm management practices have had a large impact on the poultry industry. For example, using current genetic stock and production practices, broiler chickens can weigh 2 kg in about 34 days. Forty-five years ago it would have typically taken over 60 days. These impressive advances have been made using traditional selective breeding methods and more recently by using genomics. Now, with the availability of precision genome engineering tools there are new opportunities to improve poultry production above and beyond those achievable by traditional means. One major opportunity is disease resilience, particularly for viral diseases such as avian influenza that has devastating impacts on the poultry industry. Resilience to specific diseases can be a notoriously difficult trait to select for using traditional breeding and the latest technologies that precisely edit the genome have created new ways to address this challenge

Virtual testing of advanced composites, cellular materials and biomaterials: A review

This paper documents the emergence of virtual testing frameworks for prediction of the constitutive responses of engineering materials. A detailed study is presented, of the philosophy underpinning virtual testing schemes: highlighting the structure, challenges and opportunities posed by a virtual testing strategy compared with traditional laboratory experiments. The virtual testing process has been discussed from atomistic to macrostructural length scales of analyses. Several implementations of virtual testing frameworks for diverse categories of materials are also presented, with particular emphasis on composites, cellular materials and biomaterials (collectively described as heterogeneous systems, in this context). The robustness of virtual frameworks for prediction of the constitutive behaviour of these materials is discussed. The paper also considers the current thinking on developing virtual laboratories in relation to availability of computational resources as well as the development of multi-scale material model algorithms. In conclusion, the paper highlights the challenges facing developments of future virtual testing frameworks. This review represents a comprehensive documentation of the state of knowledge on virtual testing from microscale to macroscale length scales for heterogeneous materials across constitutive responses from elastic to damage regimes

Numerical analysis of the primary and secondary structural dynamic interaction effects on elastic floor response spectra

In modern seismic design, the assessment of seismic behavior in secondary structures relies on the evaluation of the primary structure's acceleration at the support of the secondary structure. To enable effective secondary structure design, a thorough understanding of the interaction between the primary and secondary structures is essential. This article conducts an analysis based on parametric data, delving into the dynamic interaction between these structures. In this study, both the elastic primary and secondary structures are represented as single-degree-of-freedom systems. The governing equations of motion for both the coupled and uncoupled systems are derived and solved using the numerical method. Subsequently, the floor response spectrum (FRS) is computed for both coupled and uncoupled configurations. This investigation focuses on the impact of three crucial parameters: the tuning ratio (Tr), the mass ratio (μ), and the damping ratio (ξs) on the FRS. The analytical findings reveal that dynamic interaction does not significantly affect the FRS when the mass ratio is very low, at 0.1%. However, for a range of 0.8 ≤ Tr ≤ 1.2, dynamic interaction has a substantial influence on the FRS. Additionally, this study underscores that lower damping ratios in the secondary structure result in a more pronounced coupling effect on the FRS. © 2023 MIM Research Group. All rights reserved.Department of Civil Engineering; Koneru Lakshmaiah Education FoundationThe authors acknowledge that this study is supported by Department of Civil Engineering, Koneru Lakshmaiah Education Foundation (KLEF), Vaddeswaram, Guntur, India

Enhancing seismic design of non-structural components implementing artificial intelligence approach: Predicting component dynamic amplification factors

The seismic performance of non-structural components (NSCs) has been the focus of intensive study during the last few decades. Modern building codes define design forces on components using too simple relationships. The component accelerates faster than the floor acceleration to which it is connected. Therefore, component dynamic amplification factors (CDAFs) are calculated in this work to quantify the amplification in the acceleration of NSCs for the various damping ratios and tuning ratios of the NSC, and the primary structural periods. From the analysis results, it was observed that CDAF peaks are either underestimated or overestimated by the code-based formulae. A prediction model to ascertain the CDAFs was also developed using artificial neural networks (ANNs). Following that, the suggested model is contrasted with the established relationships from the past research. The ANN model's coefficient of correlation (R) was 0.97. Hence, using an ANN algorithm reduces the necessity of laborious and complex analysis. ©2023 The author(s)

Electric field distribution in porous piezoelectric materials during polarization

High piezoelectric coupling coefficients enable the harvesting of more energy or increase the sensitivity of sensors which work using the principle of piezoelectricity. These coefficients depend on the material properties, but the manufacturing process can have a significant impact on the resulting overall coefficients. During the manufacturing process, one of the main steps is the process of polarization where a poling electric field aligns the ferroelectric domains in a similar direction in order to create a transversely isotropic material able to generate electric fields or deformations. The degree of polarization depends on multiple factors and it can strongly influence the final piezoelectric coefficients. In this paper, a study on the electric field distribution on the sensitivity of the main piezoelectric and dielectric coefficients to the polarization process is performed, focusing on porous piezoelectric materials. Different inclusion geometries are considered, namely spherical, ellipsoidal and spheres with cracks. The electric field distribution at the micro scale within a representative volume element is modelled to determine the material polarization level using the finite element method. The results show that the electric field distribution is highly dependent on the inclusion geometries and cracks and it has a noticeable impact on the equivalent piezoelectric coefficients. These results are compared with experimental measurements from published literature. Good agreement is found between the ellipsoidal model and the experimental data