Al2O3/WS2 Surface Layers Produced on the Basis of Aluminum Alloys for Applications in Oil-Free Kinematic Systems

The article presents the results of an aluminum oxide layer doped with monolayer 2H tungsten disulphide (Al2O3/WS2) for applications in oil-free kinematic systems. The results concern the test carried out on the pneumatic actuator operational test stand, which is the actual pneumatic system with electromagnetic control. The cylinders of actuators are made of Ø 40 mm aluminum tube of EN-AW-6063 aluminum alloy which is used in the manufacture of commercial air cylinder actuators. The inner surfaces of the cylinder surfaces were covered with an Al2O3/WS2 oxide layer obtained by anodic oxidation in a three-component electrolyte and in the same electrolyte with the addition of tungsten disulfide 2H-WS2. The layers of Al2O3 and Al2O3/WS2 obtained on the inner surface of the pneumatic actuators were combined with a piston ring made of polytetrafluoroethylene with carbon (T5W) material and piston seals made of polyurethane (PU). The cooperation occurred in the conditions of technically dry friction. After the test was carried out, the scanning electron microscopy with energy dispersive spectroscopy (SEM/EDS) analysis of the surface of the cylinder bearing surfaces and piston seals of the pneumatic cylinders was performed. The analysis revealed the formation of a sliding film on the cylinder surface modified with tungsten disulfide, as well as on the surface of wiper seals. Based on the SEM/EDSM tests, it was also found that the modification of the Al2O3 layer with tungsten disulfide contributed to the formation of a sliding film with the presence of WS2 lubricant, which translated into smooth cylinder operation during 180 h of actuator operation. The cylinder with the unmodified layer showed irregular operation after approximately 70 h thereof.

A Technological System for Post-Earthquake Damage Scenarios Based on the Monitoring by Means of an Urban Seismic Network

A technological system capable of automatically producing damage scenarios at an urban scale, as soon as an earthquake occurs, can help the decision-makers in planning the first post-disaster response, i.e., to prioritize the field activities for checking damage, making a building safe, and supporting rescue and recovery. This system can be even more useful when it works on densely populated areas, as well as on historic urban centers. In the paper, we propose a processing chain on a GIS platform to generate post-earthquake damage scenarios, which are based: (1) on the near real-time processing of the ground motion, that is recorded in different sites by MEMS accelerometric sensor network in order to take into account the local effects, and (2) the current structural characteristics of the built heritage, that can be managed through an information system from the local public administration authority. In the framework of the EU-funded H2020-ARCH project, the components of the system have been developed for the historic area of Camerino (Italy). Currently, some experimental fragility curves in the scientific literature, which are based on the damage observations after Italian earthquakes, are implemented in the platform. These curves allow relating the acceleration peaks obtained by the recordings of the ground motion with the probability to reach a certain damage level, depending on the structural typology. An operational test of the system was performed with reference to an ML3.3 earthquake that occurred 13 km south of Camerino. Acceleration peaks between 1.3 and 4.5 cm/s2 were recorded by the network, and probabilities lower than 35% for negligible damage (and then about 10% for moderate damage) were calculated for the historical buildings given this low-energy earthquake.

Operational Analysis of Fire Alarm Systems with a Focused, Dispersed and Mixed Structure in Critical Infrastructure Buildings

The article presents issues regarding the impact of operating conditions on the functional reliability of representative fire alarm systems (FASs) in selected critical infrastructure buildings (CIB). FAS should operate correctly under variable environmental conditions. FASs ensure the safety of people and CIB. Operational measurements for 10 representative systems were conducted in order to determine the impact of environmental conditions on FAS reliability. Selected operational indices were also determined. The next stage involved developing two models of representative FASs and the availability, pre-ageing time and operating process security indices. Determining operational indices is a rational selection of FAS technical and organizational solutions that enables the reliability level to be increased. Identifying the course of the FAS operating process security hazard changes in individual system lines, particularly at the initial operation stage, enables people that supervise the operation to affect operating parameters on an ongoing basis. The article is structured in the following order: issue analysis, FAS power supply in CIB, operational test results, selected FAS operating process models, determination of operational and security indices, and conclusions.

Development of Adobe Flash Media in Increasing Learning Interest

This research aims to develop learning media products based on Adobe Flash in Indonesian Language Courses in the Elementary School Teacher Education Study Program. This research was conducted through four main stages: define, design, develop, and disseminate. This study uses a questionnaire as a data collection instrument, adapting quantitative research methods with a quasi-experimental approach (quasi-experimental) at the implementation stage in this study. The data to be obtained in the study were collected through interviews, questionnaires, and product rating scales. This scale collected data at the product validity stage, small group trials, and primary field trials. The results of the development of learning media products using a 4D development model with seven main components. Based on the results of the feasibility validation obtained in the Expert test and the initial field test, the feasibility of the media and material the value obtained is "very high" or worth testing. Based on these results, Adobe Flash media was tested with the operational test stage, and it is known that the results were obtained at an attractive value of 3.52 in this category, "Very High" or perfect changes in student interest in learning.

Investigation of degradation of ecological hydraulic fluid

This article deals on the impact of the ecological hydraulic fluid type hydraulic environmental ester synthetic oil on operation of mini excavator hydraulic circuit. An operational test was to 500 engine hours. Hydraulic fluid is evaluated for chemical contamination. Fluid samples were taken from the mini excavator at 250 engine hours intervals. These samples were subjected to IR spectroscopic analysis, kinematic viscosity measurements at 40° C and 100° C, total acid number measurement and differential scanning calorimetry. It was found that the ecological hydraulic oil does not influence the operation of the mini excavator. Based on the achieved results, it was shown that the degradation processes during the operational test of the ecological fluid do not affect the operating parameters of the monitored machine. The presented paper also presents the results of the influence of hydraulic on the flow characteristics of the hydraulic pump.

Vehicle interior noise and vibration prediction by combination analyses of Component and Operational TPA

In this study, we propose an analytical method consisting of Operational TPA (OTPA) and Component TPA (CTPA) to predict the vehicle interior noise and vibration without the vehicle operational test in case the noise source such as engine was modified. In the proposed method, the blocked force of the noise source was obtained at a test bench and the vibration at the source attachment point on the vehicle was calculated by CTPA. After then, the response point signal (interior noise / vibration) is estimated from several reference point signals including the calculated vibration by OTPA. For the verification of this method, a simple vehicle model which is composed of four tires and a motor was prepared in addition to a test bench. OTPA was firstly applied to the vehicle model to analyze the contribution from tires and a motor to the body vibration (response point). The blocked force of a modified motor was obtained by CTPA at the test bench and the force was used to predict the response point by OTPA. Finally, the estimated interior vibration was compared with the actual measured response point vibration when the motor was replaced on the vehicle model and the accuracy was verified.

Calculated dependence of determination of actual dose of microsand and influence of its value on efficiency of coagulation process in Actiflo clarifier

Operational test of the preliminary water cleaning systems is the first and most critical stage when putting into pilot operation a water treatment plant at a thermal power plant (TPP). We have sufficient experience of equipment setting up and operating when most traditional devices of preliminary water purification are used. Also, the main stages and features of the work carried out are known, and a sufficient amount of methodological literature has been published, compared to employment of modern and promising devices. These devices include Actiflo clarifiers. The main feature of the Actiflo technology is introduction of microsand into the stream of treated water. It forms the so-called “centers” of coagulation and is used to make wastewater sludge heavier. The development of a methodology to assess the impact of the actual dose of microsand on the water clarification process will contribute to the solution of the priority task of adapting the promising Actiflo technology for water treatment systems of TPPs. In laboratory studies, the method of pilot coagulation has been used. It allows us to assess the efficiency of coagulation process using generally accepted methods of quantitative analysis of indicators of natural water quality. In subsequent industrial tests, along with the quantitative analysis of water, the actual value of the microsand dose has been assessed using measurements of the proportions of separate fractions in the formed sand-sludge pulp. The results of laboratory and industrial studies of “cold” coagulation process of the Kama River water using Actiflo clarifiers have been obtained. The dependence of efficiency effect of water clarification on the dose of coagulant and the dose of microsand has been determined. To check and maintain the operating mode of the clarifier, a method to assess the actual values of the microsand dose has been developed and proposed. The research results are applicable for low-turbidity colored surface water sources. The results of operating tests of Actiflo clarifiers can be used as practical examples for coagulating water in devices similar in design, for example, VTI-M clarifiers. The proposed method to assess the actual dose of microsand can be used as a technological parameter during the development of the parameter tables when Actiflo clarifiers are used.