Catalytic Neutralization of Water Pollutants Mediated by Dendritic Polymers

Radially polymerized dendritic compounds are nowadays an established polymer category next to their linear, branched and cross-linked counterparts. Their uncommon tree-like architecture is characterized by adjustable internal cavities and external groups. They are therefore exceptional absorbents and this attainment of high concentrations into their interior renders them ideal reac-tion media. In this framework they are applied in many environmentally benign implementa-tions. One of the most important among them is water purification though pollutant decomposi-tion. Simple and composite catalysts and photo-catalysts containing dendritic polymers and ap-plied in water remediation will be discussed jointly with some unconventional solutions and fu-ture prospects.

Preparation of Cast Metallic Foams with Irregular and Regular Inner Structure

The aim of this paper is to summarize the possibilities of foundry methods for the production of metallic foams. At present, there are a number of production technologies for this interesting material, to which increasing attention has been paid in recent years. What is unique about metallic foams is the combination of their physical and mechanical properties. As part of our research, we designed and verified four main methods of metallic foam production by the foundry technology, whose products are metallic foam castings with regular and irregular arrangements of internal cavities. All these methods use materials and processes commonly used in conventional foundry technologies. The main idea of the research is to highlight such technologies for the production of metallic foams that could be provided by manufacturing companies without the need to introduce changes in production. Moreover, foundry methods for the production of metallic foams have the unique advantage of being able to produce even complex shaped parts and can thus be competitive compared to today's established technologies, the output of which is usually only a semi-finished product for further processing. This fact was the main motivation for the research.

Key Parameters to Tailor Hollow Silica Nanospheres for a Type I Porous Liquid Synthesis: Optimized Structure and Accessibility

Based on silica hollow nanospheres grafted with an ionic shell, silica-based type I porous liquids remain poorly exploited, despite their huge versatility. We propose here to explore the main synthesis step of these promising materials with a thorough characterization approach to evaluate their structural and porous properties. Modifying the main synthesis parameter, the mechanism of the spheres’ formation is clarified and shows that the calcination temperature, the surfactant concentration as well as the micelle swelling agent concentration allow tuning not only the size of the nanospheres and internal cavities, but also the silica shell microporosity and, therefore, the accessibility of the internal cavities. This study highlights the key parameters of hollow silica nanospheres, which are at the basis of type I porous liquids synthesis with optimized structural and porous properties.

Production of technological plugs for engine box and oil system using additive technologies

Today, technological plugs designed to protect the internal cavities of parts and assembly units are manufactured using such production methods as casting or stamping. At the same time, their subsequent processing is a time-consuming process. Additive technologies can save material, save time and reduce expenses. This study considers the possibility of manufacturing technological plugs for engine box and oil system using additive technologies. The cover plugs were printed using the Fusion Deposition Modeling (FDM) method on a Russian-made ZENIT printer. PLA plastic was chosen for 3D printing. The plug models were optimised, which allowed correcting and reducing the estimated printing time. In particular, some plugs were made assemblable, which helped to avoid a large number of printing supports. The production of technological plugs using additive technology allows reducing the cost of the finished product, the weight of the plugs and the estimated time of their production.

Investigation of the technological parameters of cored castings when in a lined coquille

The article presents a number of experimental and research works on the development of the parameters of the casting technology for castings with internal cavities formed by a sand rod, by casting in a lined coquille (chill mould) with a vertical connector. The influence of gating systems with a central riser and side risers on the thickness of the casting wall shedding and on the mechanical characteristics of the cast iron alloy, including ligatures, is revealed.

Study of the Influence of the Shape of Internal Cavities on the Nature of Wave Strain Hardening

The results of a study of the influence of shapes of samples, as well as the presence of internal cavities and their shapes, on the nature of wave strain hardening (WSH) are presented. The peculiarity of the method lies in the impact of a stream of pulses on the processed material, while instant wave states, which affect the microhardness maps in the workpiece are formed in the material. These studies were carried out for the first time on a specially designed stand. The studied grades of materials were: steel 45 and bronze BRAZH 9-4. As a result of the studies performed, the geometric shape of the samples and cavities in them was revealed, which contribute to an increase in microhardness.

An innovative deep neural network–based approach for internal cavity detection of timber columns using percussion sound

Timber structures have been a dominant form of construction throughout most of history and continued to serve as a widely used staple of civil infrastructure in the modern era. As a natural material, wood is prone to termite damages, which often cause internal cavities for timber structures. Since internal cavities are invisible and greatly weaken structural load-bearing capacity, an effective method to timber internal cavity detection is of great importance to ensure structural safety. This article proposes an innovative deep neural network (DNN)–based approach for internal cavity detection of timber columns using percussion sound. The influence mechanism of percussion sound with the volume change of internal cavity was studied through theoretical and numerical analysis. A series of percussion tests on timber column specimens with different cavity volumes and environmental variations were conducted to validate the feasibility of the proposed DNN-based approach. Experimental results show high accuracy and generality for cavity severity identification regardless of percussion location, column section shape, and environmental effects, implying great potentials of the proposed approach as a fast tool for determining internal cavity of timber structures in field applications.

Implementation and Testing of a 3-D Hybrid Rapid Prototyping System Capable of Deposition and Machining

Rapid Prototyping (RP), also known as Layered Manufacturing, is a widely used method of manufacturing which has been increasingly applied in the process of design and development of new products. RP's advantages includes being able to produce internal cavities, and being able to deliver and modify prototypes without specialized tooling. New RP technologies add materials than remove materials to produce the prototype part. This simplifies the 3D part producing process to 2D layer adding processes, and permits a part to be produced directly from its computer model. A hybrid Rapid Prototyping system (HRP) developed from existing systems may provide even more flexibility.

Implementation and Testing of a 3-D Hybrid Rapid Prototyping System Capable of Deposition and Machining

Rapid Prototyping (RP), also known as Layered Manufacturing, is a widely used method of manufacturing which has been increasingly applied in the process of design and development of new products. RP's advantages includes being able to produce internal cavities, and being able to deliver and modify prototypes without specialized tooling. New RP technologies add materials than remove materials to produce the prototype part. This simplifies the 3D part producing process to 2D layer adding processes, and permits a part to be produced directly from its computer model. A hybrid Rapid Prototyping system (HRP) developed from existing systems may provide even more flexibility.

Materials Precursor Score: Modelling Chemists' Intuition for the Synthetic Accessibility of Porous Organic Cages

<div>Computation is increasingly being used to try to accelerate the discovery of new materials. One specific example of this is porous molecular materials, specifically porous organic cages, where the porosity of the materials predominantly comes from the internal cavities of the molecules themselves. The computational discovery of novel structures with useful properties is currently hindered by the difficulty in transitioning from a computational prediction to synthetic realisation. Attempts at experimental validation are often time-consuming, expensive and, frequently, the key bottleneck of material discovery. In this work, we developed a computational screening workflow for porous molecules that includes consideration of the synthetic difficulty of material precursors, aimed at easing the transition between computational prediction and experimental realisation. We trained a machine learning model by first collecting data on 12,553 molecules categorised either as `easy-to-synthesise' or `difficult-to-synthesise' by expert chemists with years of experience in organic synthesis. We used an approach to address the class imbalance present in our dataset, producing a binary classifier able to categorise easy-to-synthesise molecules with few false positives. We then used our model during computational screening for porous organic molecules to bias towards precursors whose easier synthesis requirements would make them promising candidates for experimental realisation and material development. We found that even by limiting precursors to those that are easier-to-synthesise, we are still able to identify cages with favourable, and even some rare, properties. </div>