Sticky Conditions Research Articles

A Reliability Analysis of Steam Condenser Instrumentation Using Failure Mode and Effect Analysis (FMEA)

Abstract—PT PLN Nusantara Power UP Tenayan is a steam power plant (PLTU) with a capacity of 2 x 110 MW which is a buffer for the electricity system in the Central Sumatra section. In the production process of PT PLN Nusantara Power UP Tenayan it does not always go well,. So that it will have an impact on the production stages of the power plant. One of the production machines that often fails and disrupts the production stage is the steam condenser. This research uses the Failure Mode And Effect Analysis Method which aims to identify the type of failure, cause of failure, effect of failure, and determine the RPN value. The research phase begins with data collection from literature studies, interviews, field observations, data analysis, FMEA analysis, results and discussion, conclusions. Based on the results of the RPN calculation, each component of the steam condenser instrumentation does not exceed the RPN standard limit of less than 200, although the temperature indicator has the highest RPN value but is still categorized as reliable and not recommended for immediate maintenance action. The results of identifying the type of failure are that there are inaccurate indications, there are switches with sticky conditions, there are displays that are unclear or blurry, and there is a mismatch between the data displayed in the DCS and the data displayed in the local area. For recommended actions on the steam condenser instrumentation components, among others, carry out more incentive maintenance every 3 months, make improvements to the specifications of the switch according to the amount of pressure to be measured, move the sensor to a safer area and protected from water exposure, carry out a zero calibration process on the steam condenser instrumentation components every six months.

CEOs’ Optimism in Cost Behavior Asymmetry: A Content Analysis

This study aims to examine the effect of CEOs’ optimism on the asymmetry of cost behavior, namely cost stickiness (CS). A sticky condition occurs when the increase costs due to the increase in sales is greater than the decrease in costs during the decrease in sales. This study measures CEOs’ optimism by conducting content analysis using the DICTION application. The results of this study indicate that the level of optimism increases CS. These results contribute to behavioral sciences in management accounting, especially in relation to the role of the upper echelon in corporate strategic decisionmaking. The results of this study have implications for the appraisal of management performance, when looking at the fact that there is sticky-cost behavior. This sticky behavior is thought to be intended to restore the situation to an advantageous position. The previous literature states that this asymmetry occurs due to deliberate decision-making by decision-makers. Unlike previous research, this study uses the upper echelon approach, with the individual CEOs as proxy. The upper echelon theory states that the characteristics of the leadership will affect a company's strategy, so they have an impact on company performance, including decision-making regarding resource-capacity management.

Coefficient of restitution of sub-10 nm silver nanoparticles on an adhesive surface under repulsive and sticky conditions

Coefficient of restitution of sub-10 nm silver nanoparticles on an adhesive surface under repulsive and sticky conditions

Prediction of regions of coalescence and agglomeration along a spray dryer—Application to skim milk powder

Spray drying is a well-established method used in the food industry for production of powders, such as dry milk, coffee, tea, and soup. The operating conditions of spray dryers depend on the product and chamber design. Thus scaling up the process is complex, and simulation tools are needed to reduce time and cost, and to enhance quality of the final product. In this study a validated distributed-parameter model for predicting drying of single particles was combined with a CFD simulation model of an eight-meter pilot dryer to investigate drying kinetics of skim milk powders. A qualitative assessment of the effect of water diffusivity values on preconditions for agglomeration and a multi-scale analysis of coalescence and agglomeration regions were performed. Results showed that accurate water diffusivity values and sticky conditions have to be implemented when modelling spray drying to investigate preconditions for coalescence and agglomeration. The results also showed the need to simulate surface conditions of particles during spray drying to predict probable regions of coalescence and agglomeration. In conclusion, the applied methodology allows understanding of the stickiness ability of a product and size of the chamber. The methodology can be used to support preliminary design of spray dryers.

Distribution and type of sticky spots at the centre of a deglacial streamlined lobe in northeastern Manitoba, Canada

The distribution of basal drag zones (sticky spots) underneath palaeo‐ice streams or lobes is largely unknown. We investigated the centre of the large (300 km long and up to 400 km wide) deglacial Hayes Lobe in NE Manitoba, Canada, by focusing on surficial till and its composition to get insights into dispersal patterns and their potential relationships to areas of basal drag. Subglacial bed roughness is a good criterion to identify areas of basal drag, but till composition may provide important insights across smoother beds. The onset zone of the Hayes Lobe overlies Palaeozoic Carbonate Platform rocks, whereas the majority of the lobe overlies the low‐lying Canadian Shield. We show that, within a 3500‐km2 central area of this lobe, calcareous detritus within the till has been transported over 100 km within subglacial environments of reduced ice‐bed coupling and fast ice flow. Six per cent of samples (n = 782), however, outline 0.2 to 4 km wide spots with a dominantly local composition. The glacial history and composition indicate that the till within these spots contains high inheritance from a pre‐Late Wisconsinan ice‐flow phase, which we suggest was protected beneath sticky spots (low erosion, high strength) during transport of substantial calcareous detritus to the area. Furthermore, our findings show that local till spots are present within streamlined landforms, as well as till blankets or veneers over bedrock. This diverse geomorphology indicates that the process of drumlinization within the deglacial Hayes Lobe does not appear to have been responsible for significant sediment transport or deposition across the study area. The overall record thus indicates potentially complex spatiotemporal shifts between calcareous till deposition, sticky conditions, erosion and drumlinization – which supports the subglacial bed mosaic model.

Fouling and pressure drop analysis of milk powder deposition on the front of parallel fins

One method to reduce the energy consumption of industrial milk spray dryers is to recover waste heat from the exhaust dryer air. A significant challenge associated with this opportunity is the air contains a small amount of powder that may deposit on the face and surfaces of a recuperator. This paper introduces a novel lab based test that simulates powder deposition on a bank of parallel plate fins at exhaust dryer air conditions. The fin bank acts like the face of a typical finned tube row in a recuperator. The aim of this study is to look at how deposition on the front of fins is affected by the air conditions. Results show similar characteristics to other milk powder deposition studies that exhibit a dramatic increase in deposition once critical stickiness levels are reached. As powder deposits on the face of the fins, the pressure drop across the bank increases until eventually an asymptote occurs, at which point the rates of deposition and removal are similar. For very sticky conditions, deposition on the face of the fins can cause a rise in the pressure drop by as much as 65%. The pressure drop has also been successfully related to the percentage of open frontal area of the fins with and without deposition. Deposition inside and at the rear of the fin bank was found to be minimal.

A facile process for preparing superhydrophobic nickel films with stearic acid

Nickel surface with nanocone array structure was fabricated by electrodeposition. By controlling electrodeposition condition, various nickel films with different cone sizes were also fabricated. Wettability results revealed that with the increase of cone height, water contact angles increased from 148°to 154°while sliding contact angles dramatically decreased from 90° (sticky condition) to nearly 0°. Three-phase contact model and a simple calculation were given to demonstrate the relations between sliding angles and surface structures.

Dispatches

Dispatches

A modified cyclone stickiness test for characterizing food powders

A cyclone stickiness test device from a preliminary work was modified and used for characterizing stickiness behaviour of food powders. This test device employed the principle of particle dynamics in cyclone section of a spray dryer. The device was more compacted and consisted of temperature–humidity controlled air generator and cyclone test chamber. Characteristic temperature–humidity curves were determined and served as the maximum test conditions. Skim milk powder was used as a model for stickiness testing. The sample was subjected to various air conditions in the cyclone and stickiness conditions were determined. Surface moisture content and glass transition temperature at sticky point were also analysed. It was found that as the particle surface temperature increased humidity at which stickiness occurred decreased. Stickiness curve was drawn to separate between sticky and non-sticky conditions. The curve of glass transition temperature vs equilibrium surface moisture content at sticky points was obtained. It was found that the sticky curve laid at 11.4 °C above the glass transition temperature line.

Multimodal feedback for the acquisition of small targets

This paper examines how multimodal feedback assists small-target acquisition in graphical user interfaces. All combinations of three feedback modes are analysed: non-speech audio; tactile; and pseudo-haptic ‘sticky’ feedback. The tactile conditions used stimulation through vibration (rather than force-feedback), and the sticky conditions were implemented by dynamically reconfiguring mouse control-display gain as the cursor entered the target. Results show that for small, discretely located targets all feedback modes reduce targeting times, with stickiness providing substantial improvements. Furthermore, stickiness and tactile appear to combine well. However, the results of a more ecologically oriented menu-selection task show the need for caution, revealing that excessive feedback can damage interaction though ‘noise’ that interferes with the acquisition of neighbouring targets.

Effect of adsorption on nanoindentation test

The contact stiffness widely used in nanoindentation test is based on the Hertzian contact theory for zero-interfacial friction (slip boundary condition), in which the effect of adhesion energy is ignored. However, in the real situation, the adhesion energy may not be negligible when the contact is adhesive. A solution of the contact stiffness is derived by using adhesive contact theory for both frictionless condition (the famous Johnson–Kendall–Roberts theory) and the sticky condition. The results show that the nominal contact stiffness depends on the adhesion energy and indenter size as well as the load applied to indenter. For a large size of indenter and small load, the adhesion energy controls the contact process; while for a large load, the elastic deformation dominates, in which the nominal contact stiffness approaches the result based on the Hertzian contact theory.

Sticky condition, silky solution

Sticky condition, silky solution

粉体の形態制御における造粒技術

Granulation techniques have been developed to produce granular materials, such as all forms of granules, small compacts, coating particles, and small grains or prills, for demand application in widely differing industries. A primary objective in this review is to present a generalized accouts of the diverse granulation methods in a systematic way. In the case of size-enlargement of fine powders, there are two principal modes of granulation. One is achieved by tumbling, agitating, or fluidizing raw materials in the presence of liquid binders, and the other includes granulation processes in which materials are forced to flow in a plastic or sticky condition through dies or screens or in molds. The former is especially reviewed from a design viewpoint of granulation processes.