scholarly journals Study on parameters on cutting AAC by wires

Author(s):  
Lưu Thanh Tùng

Autoclaved Aerated Concrete (AAC) is a Lightweight, Load-bearing, High-insulating, Durable building product, which is produced in a wide range of sizes and strengths. AAC Blocks is lightweight and when compared to the red bricks, AAC blocks are three times lighter. AAC block is rapidly developing in Vietnam. The block has more advantages such as precast, and easy installation. AAC is produced from the common materials: lime, sand, cement and water, and a small amount of rising agent. After mixing and molding, it is then autoclaved under heat and pressure to create its unique properties. Then, the AAC block will be cut into block brick by steel wire. When cutting the ACC block, the block brick surface must be smooth so that it is unnecessary to mortar. Furthermore, the roughness of the surface must be smaller than 0.1mm to paint the wall easily. The block dimension also need high precision so that the wall will be straight when blocks are superposed. However, in this paper, the roughness of the block surface will be only researched because the roughness will decide the cost, and the dimension decide the estheticism of wall. The block is made by using steel wires to cut big AAC blocks into small blocks. Effects of processing parameters on the performance of the steel wire sawing processes are wire speed, feed rate and tension. Each parameter will affect surface quality with different effects. In addition, these parameters affect each other, which causes scratches on the AAC surface. Experiments will be made to measure the height of roughness with the change of wire speed, feed rate and tension. The best parameters will be found, which helps the AAC manufacturer to obtain the higher quality.

Author(s):  
Beom-Taek Jang ◽  
Seock-Sam Kim

Steel wires are critical load-bearing components in a wide range of applications such as elevator, cranes, mine haulage etc. The traction machine of elevator which transmits power to wire rope causes micro-slip between wire rope and sheave during reciprocating action. The lubrication condition of wire rope is also changed due to the lack of grease. This study focuses on the wear behavior of steel wire and effect of both dry and grease conditions by using the rolling/sliding contact wear tester done under various slip ratios and rolling speeds. The experimental results of the wear volume curve against the number of revolutions under the grease condition are compared with the results under dry condition. The worn surface of steel wire and the size of wear particles were observed by SEM. In order to quantify the wear amount of steel wire we established an equation and finally obtained the wear coefficient.


2018 ◽  
Vol 278 ◽  
pp. 72-77 ◽  
Author(s):  
Marina Polyakova ◽  
Yulia Efimova

At present time tendencies in the development of engineering and technologies in the manufacturing the metal ware need the effective complex impact on material microstructure by methods of different nature. Special attention should be paid to the combined processes of deformational treatment which are constructed on such basic operations as drawing, rolling, pressing, etc. Despite a plenty of studies and high efficiency of combined methods the problem of understanding the scientific grounds for choice the processing parameters which ensure the guaranteed level and high stability of metals and alloys properties has not been solved jet. Medium carbon steel is used for a wide range of metal ware products. Medium carbon steel wire with 0.5 %C was chosen for the experiments. It was subjected to different kinds of deformational processing such as tensile deformation, alternating bending, twisting and their combination. Complex of experimental research was carried out in order to study the influence of different kinds of plastic deformation on the medium carbon steel wire microstructure. By scanning electron-microscope analysis the peculiarities of pearlite behavior after deformational processing with different total deformation degree were studied. The comparative analysis of cementite changing after different kinds of deformation was conducted.


Author(s):  
A. Zare Zardiny ◽  
F. Hakimpour

Abstract. Due to the importance of spatial data in decision making and the cost of collecting these data, in recent years various communities have collaborated on spatial data collection. In these communities some expert and non-expert volunteers record their observations of a region in order to create a map. In these activities one of the most effective tools for recording observations is the sketch map. Due to ease of use and no need to comply with the common rules in Geospatial Information Systems, sketch maps can be drawn by a wide range of people. Because these maps are easy to use and following the GIS rules is not required, sketch maps can be drawn by a wide range of people. Although several studies have focused on raising the level of participation of ordinary people in the field of mapping, less attention has been given to the role of kids as an important part of the society. Hence, this paper including a field study examines the effect of collective spatial cognition of kids in a community mapping activity. For this purpose, the sketches drawn by some school kids are matched and then integrated together, and finally, the output of this process is compared with available metric maps. The results of this study show that despite the stringent conditions and the low age of the participants, the results have been beyond expectations. In this study, kids have provided several points of interest as well as more descriptive information of the region compared to the available data downloaded from OpenStreetMap and Google Maps. Therefore, the output of this study can be used to enrich the available metric map.


2020 ◽  
Vol 23 (10) ◽  
pp. 1182-1194
Author(s):  
A.A. Akhmetzyanov ◽  
A.Yu. Sokolov

Subject. The article focuses on the advanced time-driven tools for allocating overhead expenses, which are based on process-based budgeting. Objectives. We articulate a technique for cost allocation so as to assess the cost of each process with reference to the common time driver. Methods. The study relies upon methods of systematization, classification, analogy and comparison, and summarizes the scientific literature on the subject. Results. The article presents our own suggestions on implementing TD-ABC and TD-ABB into the strategic management accounting process of developer companies. The principles were proved to help more effectively allocate overhead expenses and assess the capacity load of each process performed by functions, departments and employees. Carrying out a comparative analysis, we found certain reserves for utilizing resources more effectively. Conclusions and Relevance. The findings are of scientific and practical significance and can be used by developer and construction businesses. The conclusions can prove helpful for scientific papers, student books, and further research.


Author(s):  
Nataliya Stoyanets ◽  
◽  
Mathias Onuh Aboyi ◽  

The article defines that for the successful implementation of an innovative project and the introduction of a new product into production it is necessary to use advanced technologies and modern software, which is an integral part of successful innovation by taking into account the life cycle of innovations. It is proposed to consider the general potential of the enterprise through its main components, namely: production and technological, scientific and technical, financial and economic, personnel and actual innovation potential. Base for the introduction of technological innovations LLC "ALLIANCE- PARTNER", which provides a wide range of support and consulting services, services in the employment market, tourism, insurance, translation and more. To form a model of innovative development of the enterprise, it is advisable to establish the following key aspects: the system of value creation through the model of cooperation with partners and suppliers; creating a value chain; technological platform; infrastructure, determine the cost of supply, the cost of activities for customers and for the enterprise as a whole. The system of factors of influence on formation of model of strategic innovative development of the enterprise is offered. The expediency of the cost of the complex of technological equipment, which is 6800.0 thousand UAH, is economically calculated. Given the fact that the company plans to receive funds under the program of socio-economic development of Sumy region, the evaluation of the effectiveness of the innovation project, the purchase of technological equipment, it is determined that the payback period of the project is 3 years 10 months. In terms of net present value (NPV), the project under study is profitable. The project profitability index (PI) meets the requirements for a positive decision on project implementation> 1.0. The internal rate of return of the project (IRR) also has a positive value of 22% because it exceeds the discount rate.


Alloy Digest ◽  
1976 ◽  
Vol 25 (2) ◽  

Abstract Copper Alloy No. 268 is a copper-zinc alloy with excellent cold-working properties and good resistance to corrosion. It can be cold worked by all the common fabrication processes and has a wide range of applications. This datasheet provides information on composition, physical properties, hardness, elasticity, tensile properties, and shear strength as well as fatigue. It also includes information on corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: Cu-306. Producer or source: Brass mills.


Author(s):  
Matthew S. Seligmann

As this book has shown the common conception that ‘Churchill’s “radical phase” was cast to the winds’ when he was put in charge of the Navy in October 1911, although well established in the literature, is not, in fact, accurate.1 The radical President of the Board of Trade, eager to improve the lives of the poor, became the radical Home Secretary, no less enthusiastic for social reform, who then became the radical First Lord of the Admiralty, imbued with both a desire and, perhaps more importantly, a will to intervene in order to better conditions for those who served in the Royal Navy. Accordingly, he embarked upon a major programme of improvement across a wide range of different areas all of which affected the everyday life of sailors. Alcohol intake, sexual behaviour, religious practice, corporal punishment, as well as pay and equality of progression, all came under the spotlight while Churchill was First Lord. Of course, not all of the new measures were successful and not all were progressive in the modern understanding of the term, but all of them represented significant attempts to push forward a radical agenda for change....


Author(s):  
Pete Dale

Numerous claims have been made by a wide range of commentators that punk is somehow “a folk music” of some kind. Doubtless there are several continuities. Indeed, both tend to encourage amateur music-making, both often have affiliations with the Left, and both emerge at least partly from a collective/anti-competitive approach to music-making. However, there are also significant tensions between punk and folk as ideas/ideals and as applied in practice. Most obviously, punk makes claims to a “year zero” creativity (despite inevitably offering re-presentation of at least some existing elements in every instance), whereas folk music is supposed to carry forward a tradition (which, thankfully, is more recognized in recent decades as a subject-to-change “living tradition” than was the case in folk’s more purist periods). Politically, meanwhile, postwar folk has tended more toward a socialist and/or Marxist orientation, both in the US and UK, whereas punk has at least rhetorically claimed to be in favor of “anarchy” (in the UK, in particular). Collective creativity and competitive tendencies also differ between the two (perceived) genre areas. Although the folk scene’s “floor singer” tradition offers a dispersal of expressive opportunity comparable in some ways to the “anyone can do it” idea that gets associated with punk, the creative expectation of the individual within the group differs between the two. Punk has some similarities to folk, then, but there are tensions, too, and these are well worth examining if one is serious about testing out the common claim, in both folk and punk, that “anyone can do it.”


Author(s):  
Yimin Xie ◽  
Jinbo Ning

Abstract Background/Purpose The Nuss procedure is the most common surgical repair for pectus excavatum (PE). Surgical steel wires are used in some modifications of the Nuss procedure to attach one or both ends of a support bar to the ribs. During follow-up, wire breakage was found in some cases. Patients with wire breakage may undergo prolonged bar removal surgery and may be exposed to excessive radiation.In this study, we had a series of patients who received polydioxanone suture (PDS) fixations instead of steel wires. This retrospective study was conducted to explore the differences between these two fixation materials in the incidence of related complications and efficacies. Furthermore, we attempted to observe whether the two materials lead to similar surgical efficacy in the Nuss procedure, whether they have divergent effects on the bar removal surgery, and whether PDS can reduce the risks due to steel wire breakage as expected. Methods We retrospectively studied PDS and surgical steel wires as fixation materials for the Nuss procedure in children with congenital PE and reviewed the outcomes and complications. A total of 75 children who had undergone Nuss procedure repairs and bar removals from January 2013 to December 2019 were recruited to participate in this study. They were divided into three groups: the PDS group, the unbroken wire (UBW) group, and the broken wire (BW) group, according to the fixation materials and whether the wires had broken or not. Moreover, we selected the duration of operation (DO), intraoperative blood loss (BL), bar displacement (BD), postoperative pain score (PPS), and incision infection as the risk indicators and the postrepair Haller index (HI) as the effectiveness indicator. These indicators were statistically compared to determine whether there were differences among the three groups. Results One BD occurred in the PDS and BW groups while none took place in the UBW group. No incision infection was found in any of the groups. The PDS group had the shortest DO, while the DO in the UBW group was shorter than that in the BW group (p < 0.05). BL in the PDS group was less than that in the other two groups (p < 0.05). Additionally, no difference was observed in BL between the BW and UBW groups (p > 0.05). The PPS of the PDS group was less than that of the BW group (p < 0.05), whereas no differences were found between the other two groups. No statistical difference emerged in HI among the groups (p > 0.05). Conclusion PDS fixation results in a similar repair outcome and shows certain advantages in the DO, BL, and PPS; also, PDSs are safe and effective in the Nuss procedure. Level of evidence Level III.


Materials ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1486
Author(s):  
Eugene B. Caldona ◽  
Ernesto I. Borrego ◽  
Ketki E. Shelar ◽  
Karl M. Mukeba ◽  
Dennis W. Smith

Many desirable characteristics of polymers arise from the method of polymerization and structural features of their repeat units, which typically are responsible for the polymer’s performance at the cost of processability. While linear alternatives are popular, polymers composed of cyclic repeat units across their backbones have generally been shown to exhibit higher optical transparency, lower water absorption, and higher glass transition temperatures. These specifically include polymers built with either substituted alicyclic structures or aromatic rings, or both. In this review article, we highlight two useful ring-forming polymer groups, perfluorocyclobutyl (PFCB) aryl ether polymers and ortho-diynylarene- (ODA) based thermosets, both demonstrating outstanding thermal stability, chemical resistance, mechanical integrity, and improved processability. Different synthetic routes (with emphasis on ring-forming polymerization) and properties for these polymers are discussed, followed by their relevant applications in a wide range of aspects.


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