Catalytic Copyrolysis of Heavy Oil with Polypropylene

Catalytic and noncatalytic copyrolysis of plastic and heavy oil was studied using thermogravimetric analysis (TGA), pyrolysis reactor experiments, and GC analysis of the formed liquid. As revealed by the TGA experiments, predegradation as a pretreatment method had further lowered the decomposition temperature of polypropylene– (PP−) bitumen mixtures and reduced the severity of catalyst deactivation by coke. The presence of PP in the copyrolysis had increased the liquid yield and decreased the coke yield. The presence of PP in the copyrolysis had shifted the product distribution from heavier to lighter fractions while copyrolysis using predegradation displayed the highest percentage of C5–C9 and C9–C14 fractions. Based on the performance of the catalysts, C5–C14 was produced in the following order, HY > 20% USY > APC > K30, while C14–C20 was produced in the reverse order of K30 > 20% USY > APC > HY. In-depth analysis of the percentage product distribution confirmed the availability of synergies during the thermal copyrolysis of PP and Ex-Mwambe heavy oil. Predegradation as pretreatment method has intensified the contact between the two feed constituents, enabling synergistic effects to materialize. The excess percentage of C5–C9 and the insignificant amount of C20+ produced from the thermal copyrolysis affirmed the possibility that the presence of PP facilitates the conversion of waxy hydrocarbons into lighter products. the conversion of waxy hydrocarbons into lighter products. Coke components from predegradation method are more volatile while the coke formed during normal mixing pyrolysis contained a higher percentage of hard coke

Experimental investigation of substandard RC columns confined with SRG jackets under compression

This paper aims to explore the behaviour of substandard reinforced concrete (RC) columns confined with Steel-Reinforced Grout (SRG) jackets under monotonically increasing uniaxial compression. A total of 24 specimens of short RC columns of square cross section were designed to fail due to longitudinal reinforcement buckling. Single-layered SRG jackets were applied to 18 of these specimens, whereas the rest served for control without SRG jackets. Parameters of this investigation were the type and density of the steel fabric as well as the corner radius of the cross section. The employed SRG jacketing managed to increase the strength and strain capacity and postpone the buckling of the longitudinal steel bars to occur at higher compressive strain level. Confinement effectiveness with respect to the lateral confining pressure exerted by the used SRG jacketing is discussed along with the observed mode of failure

The Structural Performance of Stone-Masonry Bridges

The structural performance of old stone-masonry bridges is examined by studying such structures located at the North-West of Greece, declared cultural heritage structures. A discussion of their structural system is included, which is linked with specific construction details. The dynamic characteristics of four stone bridges, obtained by temporary in situ instrumentation, are presented together with the mechanical properties of their masonry constituents. The basic assumptions of relatively simple three-dimensional (3-D) numerical simulations of the dynamic response of such old stone bridges are discussed based on all selected information. The results of these numerical simulations are presented and compared with the measured response obtained from the in situ experimental campaigns. The seismic response of one such bridge is studied subsequently in some detail as predicted from the linear numerical simulations under combined dead load and seismic action. The performance of the same bridge is also examined applying 3-D non-linear numerical simulations with the results used to discuss the structural performance of stone-masonry bridges that either collapsed or may be vulnerable to future structural failure. Issues that influence the structural integrity of such bridges are discussed combined with the results of the numerical and in situ investigation. Finally, a brief discussion of maintenance issues is also presented

The Seismic Behaviour of Stone Masonry Greek Orthodox Churches

The seismic behaviour of structural systems representing Greek Orthodox churches is examined. All these churches are made of stone masonry in various architectural forms. During the years such churches developed damage to their stone masonry structural elements due to the amplitude of the gravitational forces acting together with the seismic forces. In certain cases such damage was amplified due to the deformability of the foundation. The behaviour of structural systems representing Greek Orthodox churches was simulated through linear and non-linear numerical models. The numerical results together with assumed strength values or failure criteria were utilized to predict the behaviour of the various masonry parts in in-plane shear and flexure as well as out-of-plane flexure. The deformability of the foundation partly explains the appearance of structural damage as can be seen both from observations and the numerical predictions. A limit-state methodology is presented whereby the demands obtained from linear elastic numerical models combined with limit-state in-plane behaviour of unreinforced stone masonry walls in shear/flexure or diagonal tension can yield reasonably good predictions of observed behaviour. Furthermore, the possibilities offered by non-linear inelastic numerical analyses as alternative means for examining the performance of unreinforced stone masonry walls is also briefly presented. Towards this objective, non-linear inelastic numerical simulation results are presented that yield reasonably good agreement with the relevant measured behaviour of stone masonry wall specimens of prototype dimensions that were subjected to simultaneous vertical compression and horizontal cyclic seismic-type loading in the laboratory. The obtained results from these specimens were utilized to also validate an expert system based on this limit-state methodology. Again, the observed behaviour was predicted with reasonable accuracy in terms of bearing capacity and mode of failure by this expert system

Integrated Circuit (IC) Chip with a Self-Contained Fluid Sensor and Method of Making the Chip

An integrated circuit (IC) chip with a self-contained fluid sensor and method of making the chip. The sensor is in a conduit formed between a semiconductor substrate and a non-conductive cap with fluid entry and exit points through the cap. The conduit may be entirely in the cap, in the substrate or in both. The conduit includes encased temperature sensors at both ends and a central encased heater. The temperature sensors may each include multiple encased diodes and the heater may include multiple encased resistors

Project Elements: A computational entity-component-system in a scene-graph pythonic framework, for a neural, geometric computer graphics curriculum

We present the Elements project, a computational science and computer graphics (CG) framework, that offers for the first time the advantages of an Entity-Component-System (ECS) along with the rapid prototyping convenience of a Scenegraph-based pythonic framework. This novelty allows advances in the teaching of CG: from heterogeneous directed acyclic graphs and depth-first traversals, to animation, skinning, geometric algebra and shader-based components rendered via unique systems all the way to their representation as graph neural networks for 3D scientific visualization. Taking advantage of the unique ECS in a a Scenegraph underlying system, this project aims to bridge CG curricula and modern game engines, that are based on the same approach but often present these notions in a black-box approach. It is designed to actively utilize software design patterns, under an extensible open-source approach. Although Elements provides a modern, simple to program pythonic approach with Jupyter notebooks and unit-tests, its CG pipeline is not black-box, exposing for teaching for the first time unique challenging scientific, visual and neural computing concepts.Comment: 8 pages, 8 figures, 2 listings, submitted to EuroGraphics 2023 education trac

Progressive tearing and cutting of soft-bodies in high-performance virtual reality

We present an algorithm that allows a user within a virtual environment to perform real-time unconstrained cuts or consecutive tears, i.e., progressive, continuous fractures on a deformable rigged and soft-body mesh model in high-performance 10ms. In order to recreate realistic results for different physically-principled materials such as sponges, hard or soft tissues, we incorporate a novel soft-body deformation, via a particle system layered on-top of a linear-blend skinning model. Our framework allows the simulation of realistic, surgical-grade cuts and continuous tears, especially valuable in the context of medical VR training. In order to achieve high performance in VR, our algorithms are based on Euclidean geometric predicates on the rigged mesh, without requiring any specific model pre-processing. The contribution of this work lies on the fact that current frameworks supporting similar kinds of model tearing, either do not operate in high-performance real-time or only apply to predefined tears. The framework presented allows the user to freely cut or tear a 3D mesh model in a consecutive way, under 10ms, while preserving its soft-body behaviour and/or allowing further animation.Comment: 9 pages, 11 figures, 3 tables, submitted to "International Conference on Artificial Reality and Telexistence, Eurographics Symposium on Virtual Environments 2022