Design, Manufacturing, and Performance Evaluation of a Novel Smart Roller Bearing Equipped with Shape Memory Alloy Wires

In this study, a new type of seismic isolation device, called SMA wire-based roller bearing (SMA-RB) is developed and introduced. The SMA-RB has been designed, manufactured, and experimentally tested. This bearing consists of cylindrical roller bearings and SMA wires with straight or cross configurations, as supplementary damping elements. In such a smart bearing, the superelastic SMA wires are passed through the hooks/pulleys attached to the supporting plates of the bearings in different configurations. The rollers provide lateral flexibility, and SMA wires supply energy dissipation and self-centering properties. In the manufacturing stage, a new mechanism for coupling wires (i.e. SMA wire joiner/coupler) is proposed. The results show that SMA wires, made of Nickle Titanium (NiTi), provide a self-centered damping mechanism with almost zero residual deformation which can effectively control the device from over-displacement. While using pulleys and newly designed wire joiners in the SMA-RB, the bearing can experience a stable cyclic behavior. Since the rollers generate a negligible amount of frictional force, the superelastic NiTi wires with a flag-shaped hysteresis mainly contribute to the overall shear hysteretic response of the SMA-RB. A triangular-shaped constitutive model can be used to accurately describe the hysteretic behavior of SMA-RB with different wire configurations.

Preservation of the Muyu Indigenous Language with an Android-based Dictionary

Indonesia is a country rich in cultural diversity, with each culture having its own regional language characterizing the area. The Muyu language is one of the regional languages, used by the Muyu tribal community in Boven Digoel Regency, Papua Province. The language is now under the threat of abandonment by the Muyu community, especially the younger generation. One of the causes is the lack of written learning media for the language to be inherited by older speakers in the form of books and electronic dictionaries. This study will try to develop an Android-based Muyu-Indonesian-English dictionary application using the waterfall method (classic life cycle). The aim is to test students' preferences and attitudes towards the development of Muyu language knowledge. The research sample consisted of 40 respondents consisting of Muyu students at Musamus University. A questionnaire was used to measure the extent of student responses to the use of the Muyu-Indonesian-English dictionary application. The test results show that the system has no errors in carrying out the functions that have been created previously at the manufacturing stage. The three-language Muyu-Indonesian-English dictionary application is able to search for vocabulary properly and correctly in Muyu, Indonesian, and English. The attitude of students towards the usefulness of this dictionary application is measured at the medium category, meaning that the application is useful as a tool to facilitate students of the Muyu language, especially Android users, in finding vocabulary in three languages, and can be a tool for learning the Muyu language and preserving local wisdom so that it does not become extinct. Doi: 10.28991/esj-2021-SP1-06 Full Text: PDF

Non-Equilibrium Crystallization of Monotectic Zn-25%Bi Alloy under 600 g

This study investigated the influence of supergravity on the segregation of components in the Zn–Bi monotectic system and consequently, the creation of an interface of the separation zone of both phases. The observation showed that near the separation boundary, in a very narrow area of the order of several hundred microns, all types of structures characteristic for the concentration range from 0 to 100% bismuth occurred. An additional effect of crystallization in high gravity is a high degree of structural order and an almost perfectly flat separation boundary. This is the case for both the zinc-rich zone and the bismuth-rich zone. Texture analysis revealed the existence of two privileged orientations in the zinc zone. Gravitational segregation also resulted in a strong rearrangement of the heavier bismuth to the outer end of the sample, leaving only very fine precipitates in the zinc region. For comparison, the results obtained for the crystallization under normal gravity are given. The effect of high orderliness of the structure was then absent. Despite segregation, a significant part of bismuth remained in the form of precipitates in the zinc matrix, and the separation border was shaped like a lens. The described method can be used for the production of massive bimaterials with a directed orientation of both components and a flat interface between them, such as thermo-generator elements or bimetallic electric cell parts, where the parameters (thickness) of the junction can be precisely defined at the manufacturing stage.

Fiber Optic Sensors Embedded in Textile-Reinforced Concrete for Smart Structural Health Monitoring: A Review

The last decade has seen rapid developments in the areas of carbon fiber technology, additive manufacturing technology, sensor engineering, i.e., wearables, and new structural reinforcement techniques. These developments, although from different areas, have collectively paved way for concrete structures with non-corrosive reinforcement and in-built sensors. Therefore, the purpose of this effort is to bridge the gap between civil engineering and sensor engineering communities through an overview on the up-to-date technological advances in both sectors, with a special focus on textile reinforced concrete embedded with fiber optic sensors. The introduction section highlights the importance of reducing the carbon footprint resulting from the building industry and how this could be effectively achieved by the use of state-of-the-art reinforcement techniques. Added to these benefits would be the implementations on infrastructure monitoring for the safe operation of structures through their entire lifespan by utilizing sensors, specifically, fiber optic sensors. The paper presents an extensive description on fiber optic sensor engineering that enables the incorporation of sensors into the reinforcement mechanism of a structure at its manufacturing stage, enabling effective monitoring and a wider range of capabilities when compared to conventional means of structural health monitoring. In future, these developments, when combined with artificial intelligence concepts, will lead to distributed sensor networks for smart monitoring applications, particularly enabling such distributed networks to be implemented/embedded at their manufacturing stage.

Kajian Literatur Perkembangan Inovasi Teknologi Tekstil Berbasis Silikon Polimer

DEVELOPMENT OF SILICONE-BASED TEXTILE TECHNOLOGY INNOVATION - LITERATURE STUDY. The purpose of this review is to provide an overview of the key innovative pathways in developing silicone-based  textiles to date using resources available in the public domain regarding "smart textiles" which are translated into Indonesian as "Smart Textile" or "Textile Intelligent". The material of this paper is taken from various literatures which are textbooks (academic), commercial products and issued patents. Based on the literature obtained it is reported that silicone can be integrated into textiles, where integration can be achieved by inserting silicone into textile surfaces, and silicone are added at the textile or silicone manufacturing stage combined at the yarn stage. The integration method can affect the nature of the yarn network in fabrics / textiles, such as the flexibility of the fabric.

Improving the accuracy and metrological support of power meters in the frequency range from 37.5 to 178.6 GHz

To satisfy the needs for metrological support of power measurements in the frequency range from 37.5 to 178.6 GHz, the device has been developed and designed for automated measurements, calibrations and verification of wattmeters with high accuracy and the ability to adapt to various types of devices under investigation. This paper presents the composition, diagram andgeneral principle of the device. A description of the structure of isothermal calorimetric converters of autocompensation type with dry load and reference body, which are the basis of the device, is given. The implemented algorithms for converting and replacing microwave power with direct current power of the developed calorimetric wattmeters are presented. The measures taken at the manufacturing stage to minimize sources of measurement uncertainty are described. To assess the accuracy of measuring the absorbed power, a mathematical model of the conversion factor has been compiled. Corrections have been introduced into this mathematical model to improve the measurement accuracy of the reproducible microwave power. The obtained basic metrological and technical characteristics of calorimetric wattmeters and comparison equipment of the device are presented. The obtained metrological and technical characteristics correspond to the current level of standard equipment.

Unconventional Methods of Non-Destructive Tests. Part 3.

The article presents some testing methods applicable in the aviation industry. In addition to popular non-destructive methods, NDT methods used in the aviation industry (and discussed in the article) include optical holography or shearography. Structural materials used in the aviation industry as well as the importance of analyses, both at the manufacturing stage and during operation, require the performance of regular tests as a negligent approach to such activities could end up in a catastrophe.

Influence of Muscle Type on Physicochemical Parameters, Lipolysis, Proteolysis, and Volatile Compounds throughout the Processing of Smoked Dry-Cured Ham

The influence of muscle type (biceps femoris, BF and semimembranosus, SM) on physicochemical parameters, volatile compounds, and the extent of proteolysis and lipolysis during the manufacturing of smoked dry-cured ham was investigated. A total of fifty smoked hams were sampled: raw ham, after salting, smoking, drying, and ripening. Almost all physicochemical parameters were affected by muscle type, manufacturing stage and their interactions. SM had lower water, ash, NaCl content, and water activity (aw), while fat and protein content were higher after ripening compared to BF. BF showed higher L*a*b* values compared to SM. The results of texture profile analysis showed that almost all analyzed parameters were influenced by muscle type and production stage. A total of 88 volatile compounds were identified, showing an increase in its number during processing: 31 volatile compounds were identified in raw ham and 72 after the ripening phase. Aldehydes and phenols were the predominant groups of compounds, followed by alcohols, ketones, aromatic hydrocarbons, aliphatic hydrocarbons, esters, and terpenes. Muscle type and production phase significantly affected lipid oxidation and the index of proteolysis: in SM, thiobarbituric acid reactive substances (TBARS) increased faster than in BF, while proteolysis had an opposite effect and was more pronounced in BF.

Impacts of Nanosilver-Based Textile Products Using a Life Cycle Assessment

Due to their properties, silver nanoparticles (AgNPs) are widely used in consumer products. The widespread use of these products leads to the release of such nanoparticles into the environment, during manufacturing, use, and disposal stages. Currently there is a high margin of uncertainty about the impacts of nano products on the environment and human health. Therefore, different approaches including life cycle assessment (LCA) are being used to evaluate the environmental and health impacts of these products. In this paper, a comparison between four different AgNP synthesis methods was conducted. In addition, four textile products that contain AgNPs were subjected to comparison using LCA analysis to assess their environmental and public health impacts using SimaPro modeling platform. Study results indicate that using alternative methods (green) to AgNPs synthesis will not necessarily reduce the environmental impacts of the synthesizing process. To the best of our knowledge, this is the first study that has compared and assessed the environmental burdens associated with different nanosilver-based textile products at different disposal scenarios. The synthesis of 1 kg of AgNPs using modified Tollens’ method resulted in 580 kg CO2 eq, while 531 kg CO2 eq resulted from the chemical approach. Furthermore, the manufacturing stage had the highest overall impacts as compared to other processes during the life cycle of the product, while the product utilization and disposal stages had the highest impacts on ecotoxicity. Sensitivity analysis revealed that under the two disposal scenarios of incineration and landfilling, the impacts were sensitive to the amount of AgNPs.