Preparation of Adsorbents by Pyrolysis of Sludge Mixed With Steel Slag and Study on Adsorption of Chromium Ions in Water

In this study, the dewatered sludge from the sewage plant and the open-hearth steel slag of the steel plant are used as raw materials. As two wastes, they were mixed and pyrolyzed to prepare a composite absorbent. Further, the adsorption mechanism of the adsorbent to chromium ions in the sewage is explored. The pyrolysis reaction behavior of sludge mixed with steel slag was studied by the thermogravimetric analysis technology. SEM, BET, and XPS were used to analyze the specific surface area, pore size distribution, and pore structure characteristics of pyrolysis products, respectively. Moreover, a comprehensive analysis of the adsorbent was carried out for the adsorption mechanism of hexavalent chromium ions. The results show that the addition of steel slag promotes the pyrolysis of the sludge in each stage. When the content of steel slag is 80%, the increases of reaction rate are the most obvious with the largest increase of weight loss rate in each stage. The SEM results show that the enrichment of sludge on metal oxides is enhanced in the high-temperature range (600–700°C). Besides, when the content of steel slag is 40–60%, the mixture’s growth rate of the specific surface area can reach 600% and the growth rate of total pore volume can reach 350% (the situations of sludge as the baseline). Regarding the measurement of Cr(VI), the adsorption rate of the steel-slag solution is 50.93% and that of the sludge solution is 69%. However, the adsorption rate can be increased to 95% when the steel slag and sludge were mixed as an adsorption solution. In conclusion, the adsorption mechanism of Cr(VI) by additives is controlled by both physical and chemical processes. The present study provides a theoretical basis and technical support for the scientific and reasonable utilization of sludge and steel slag.

The Effect of Cooking Method and Cooked Color on Consumer Acceptability of Boneless Pork Chops

The objective was to determine the effects of sous-vide cooking and degree of doneness on consumer eating experience of pork chops when cooked color was expected to differ. The hypothesis was consumers would prefer a cooked brown color and would rate grilled chops more acceptable than sous-vide chops. Chops were cooked to 63 °C or 71 °C using either an open-hearth grill or a sous-vide device. Participants evaluated four samples for tenderness, juiciness, flavor, and overall acceptability. Participants rated a greater percentage of chops cooked sous-vide at 63 °C as tender (82.82%), juicy (55.83%) and acceptable (60.34%) compared with all other cooking method and degree of doneness combinations. Participants rated a greater percentage of sous-vide chops as tender and acceptable compared to grilled chops. Participants rated a greater percentage of chops cooked to 63 °Cas tender, juicy, flavorful, and acceptable when compared to 71 °C. Even when participants could visualize cooked color, they preferred chops cooked to 63 °C compared with chops cooked to 71 °C. Overall, participants preferred chops cooked to 63 °C compared to 71 °C regardless of the cooking method and preferred chops cooked to 63 °C using the sous-vide cooking method the most among all treatments.

The Vector of Equal Costs as a Method of Studying the Process of Industrialization (according to labor productivity data in the iron and steel industry of the Urals of the late XIX – early XX centuries)

Introduction. An attempt is made to analyze the dynamics of labor productivity in the iron-making industry of the Urals using the equal cost vector during the replacement of welding iron production technologies with cast steel production technologies in open-hearth and Bessemer furnaces, as well as to determine the heuristic potential of this method. Materials and Methods. The study uses a vector of equal costs. This vector connects the points on the graph that reflect the number of two products released per unit of resource for a certain period of time. The source of the study was the “Collections of statistical data of the mining industry of Russia”. Results. The vectors of equal costs for the production of iron and steel per worker of the iron- making industries of the Urals in 1893–1911 are constructed. The periods in the development of iron-making production are highlighted. Discussion and Conclusion. The method of equal cost vectors revealed the following: 1) rational use of labor in private factories and irrational in state-owned ones; 2) significant influence of the Nadezhdinsky Plant on the structure of iron-making industries; 3) a more precise chronological framework for the replacement of welding iron production technologies by open-hearth and seedless production, the influence of market conditions on this process; 4) the replacement of old technologies with new ones did not cause an increas

In silico biomechanical design of the metal frame of transcatheter aortic valves: multi-objective shape and cross-sectional size optimization

Transcatheter aortic valve (TAV) implantation has become an established alternative to open-hearth surgical valve replacement. Current research aims to improve the treatment safety and extend the range of eligible patients. In this regard, computational modeling is a valuable tool to address these challenges, supporting the design phase by evaluating and optimizing the mechanical performance of the implanted device. In this study, a computational framework is presented for the shape and cross-sectional size optimization of TAV frames. Finite element analyses of TAV implantation were performed in idealized aortic root models with and without calcifications, implementing a mesh-morphing procedure to parametrize the TAV frame. The pullout force magnitude, peak maximum principal stress within the aortic wall, and contact pressure in the left ventricular outflow tract were defined as objectives of the optimization problem to evaluate the device mechanical performance. Design of experiment coupled with surrogate modeling was used to define an approximate relationship between the objectives and the TAV frame parameters. Surrogate models were interrogated within a fixed design space and multi-objective design optimization was conducted. The investigation of the parameter combinations within the design space allowed the successful identification of optimized TAV frame geometries, suited to either a single or groups of aortic root anatomies. The optimization framework was efficient, resulting in TAV frame designs with improved mechanical performance, ultimately leading to enhanced procedural outcomes and reduced costs associated with the device iterative development cycle.

Hollis Croft, Sheffield, South Yorkshire: Old site and new connections

In 2017, a team from the Wessex Archaeology Sheffield office investigated a site, Hollis Croft (NGR 434990 387580), prior to the construction of a multi-million pound commercial and student housing development. Hollis Croft is one of many Sheffield’s sites where well-preserved industrial archaeology survives beneath the modern buildings. Historic building recording was followed by a watching brief, a scheme of archaeological evaluation trenching and then strip, map and sample excavations, which revealed substantial 18th-/19th-century remains of steel conversion furnaces (both cementation and crucible, constructed by Burgin and Wells and W. Fearnehough Ltd respectively). We also discovered metres of entwined brick-built flues (likely related to later steelmaking methods such as the Siemens-Martin open hearth process or Bessemer process), traces of two pubs (The Cock and The Orange Branch) and a wide range of finds – all indicative of the industrial processes and the everyday lives of the workers. Apart from the discovery of a crozzle layer covering the entire interior of the furnace (not just its base as previously thought), and the detailed impressions of the ferrous bars visible in the surface of the crozzle layer, the remains were very familiar for Sheffield and industrial archaeology. The post-excavation processes were carried out as usual following industry standards. All our findings have been brought together in a final report held in the digital archive and the physical archive (including the finds) was subsequently deposited with Museums Sheffield under SHEFM:2019.13 and Sheffield Archives. This publication is based on that final report, but edited and updated, so there are some minor differences between the documents. But, inspired by a great deal of public interest during the excavations (and Mili's love for comics), a comic book has also been created and is published here alongside what would otherwise be a more traditional offering.

IMPACT STRENGTH OF WAGON CASTINGS IN THE ASPECT OF THE INFLUENCE OF THE HARDNESS OF FERRITE AND PERLITE OF STEEL 20GL OPEN-HEARTH SMELTS

Методом оптической микроскопии провели металлографический анализ микроструктуры феррита (Фе) и перлита (II) различных образцов низколегированной стали 20ГЛ для вагонных отливок «Рама боковая» и «Балка надрессорная». Metallographic analysis of the microstructure of ferrite (Fe) and perlite (P) of various samples of low-alloy steel 20GL for the "Side frame" and "Spring beam" car castings was performed by optical microscopy.

Effect of modification on impact strength of critical carriage castings made of 20GL steel

Effect of modifiers on the basis of rare-earth and alkali-earth metals on microstructure and impact toughness of car castings made of low-alloy casting 20GL steel of open-hearth and electroarc melts on the basis of statistical and microstructural analysis is considered. The relationship between the steel impact toughness level, matrix grain parameters and non-metallic inclusions is studied.