scholarly journals Selected Properties of Hardfacing Layers Created by PTA Technology

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 134
Author(s):  
Janette Brezinová ◽  
Ján Viňáš ◽  
Anna Guzanová ◽  
Jozef Živčák ◽  
Jakub Brezina ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Light And Electron Microscopy ◽  
Base Material ◽  
Mold Material ◽  
X Ray ◽  
Plasma Transferred Arc ◽  
Transferred Arc ◽  
The Individual ◽  
The Impact

The paper presents research results on the quality of hardfacing layers made during the renovation of unheated mold surfaces designed for injection of aluminum alloys using the plasma transferred arc (PTA) technology. As mold material, the medium alloy steel X38CrMoV5-1 (H11) was used. For the formation of functional layers, three types of additives in the form of powder were applied: two types on an iron basis with the designation HSS 23 and HSS 30 and one type on a nickel basis with the designation DEW Nibasit 625-P. The hardfacing layers were made on a 120 × 350 × 50 mm plate in two layers on the plasma hardfacing machine PPC 250 R6. The quality of the layers was evaluated by means of nondestructive and destructive tests. The surface integrity of the layers was assessed using visual and capillary tests. The samples passed these tests. The impact of the parameters used and the mixing of the hardfacing metal with base material, as well as the structure analysis, were assessed by means of light and electron microscopy (SEM). The chemical composition of the elements was determined by energy-dispersive X-ray spectroscopy (EDX) analysis using a SEM microscope. The hardness of the individual layers was evaluated. Since, during operation, molds are subjected to significant wear due to friction, the friction coefficients for selected temperatures were determined by the equipment for the evaluation of tribology properties. Based on the experiments conducted, all three types of additives can be used for renovation. However, from a tribology perspective, the additive DEW Nibasit 625-P on a nickel alloy basis is recommended for renovation.

scholarly journals Characterization of a coating 316L applied by plasma transferred arc

2018 ◽  
Vol 72 (3) ◽  
pp. 139-147 ◽  
Author(s):  
Aleksandar Maslarevic ◽  
Gordana Bakic ◽  
Milos Djukic ◽  
Bratislav Rajicic ◽  
Vesna Maksimovic
Keyword(s):  
Erosion Resistance ◽  
Base Material ◽  
Impact Angle ◽  
Coating Material ◽  
Filler Material ◽  
Plasma Transferred Arc ◽  
Short Period ◽  
Transferred Arc ◽  
The Impact

Parts of industrial machines and structures are often exposed to the action of aggressive environments, which in a short period of time can provoke the loss of their integrity. It is well known that for extending the service life against erosion and corrosion, protection of the exposed structure zone by coating is frequently used. Various application methods of protective coatings are applied, and the most common are welding and thermal spraying processes. The aim of this study was characterization of coatings made of stainless steel 316L, widely used in chemical and petrochemical industries. The coating was applied on a structural steel S235JR by plasma transferred arc using powder as a filler material. Due to a number of advantages, the plasma transferred arc (PTA) surfacing process has found significant usages in the field of surface protection. This paper presents results of hardness measurements in characteristic zones of the coating and the base material, as well as microstructural characterization of coatings using optical and scanning electron microscopy. Results of EDS analysis of the coating and hardness measurements indicated that a relatively high dilution (26.1 %) of the base material (BM) and the filler material (FM) occurred in a very narrow zone above the fusion line, and thus did not significantly affect the chemical composition of the rest of the coating. Also, erosion resistance tests of coatings were performed by changing the basic functional parameters that is the impact angle and the speed of erodent particles. It was observed that the erosion resistance of the coating material decreases approximately linearly with the increase of the particle speed. Also, with the increase of the impact angle of the erodent (up to 45 ?), the mass loss of the coating material is increased.

scholarly journals Mobility and Bioavailability of Metal(loid)s in a Fluvial System Affected by the Mining and Industrial Processing of Pb

Geosciences ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 167
Author(s):  
Unai Cortada ◽  
María Carmen Hidalgo ◽  
Julián Martínez ◽  
María José de la Torre
Keyword(s):  
Total Concentration ◽  
Rare Metal ◽  
Mining District ◽  
X Ray ◽  
Industrial Processing ◽  
Solids Concentration ◽  
Mobile Fraction ◽  
Type Water ◽  
The Impact

The abandoned mining district of Linares (South Spain) is marked with waste from the mining and the processing of metal ores that pose an environmental hazard to watercourses. A combined analysis of waste, sediments and water was carried out to analyse the impact of a smelter on Baños Creek. The composition of the facility waste was determined using X-ray diffractometry and scanning electron microscopy. The total contents of the metal(loid)s in the waters and sediments of the watercourse were analysed, and sequential metal(loid) extraction of solid samples was carried out. The facility wastes consisted mainly of secondary minerals, such as natropharmacosiderite and spertiniite, as well as rare metal salts, such as mopungite and NaPb2(CO3)2(OH). The leachates generated by these wastes were highly alkaline, with a pH of 10 and a total dissolved solids concentration of approximately 9 g L−1. This Na-bicarbonate-type water had an As concentration above 200 mg L−1 and elevated levels of Pb, Sb and Zn (5029 µg L−1, 841 µg L−1 and 525 µg L−1, respectively). This highly contaminated lixiviate had a significant effect on the chemical quality of the waters and the bioavailability of metal(loid)s in the creek sediments, especially in the headwaters. In this zone, the As, Pb, Sb and Zn concentrations in the most mobile fraction of the sediments reached 1035 mg kg−1, 261 mg kg−1, 45 mg kg−1 and 30 mg kg−1, respectively. By comparison, smelter slag and mining waste have a much lower impact on the waters and the mobile fraction of the sediments, while significantly increasing the total concentration of these potentially toxic elements in creek sediments.

scholarly journals Knowledge sharing in open source software communities: motivations and management

2015 ◽  
Vol 19 (4) ◽  
pp. 791-813 ◽  
Author(s):  
Zilia Iskoujina ◽  
Joanne Roberts
Keyword(s):  
Knowledge Sharing ◽  
Open Source ◽  
Open Source Software ◽  
Online Communities ◽  
Descriptive Analysis ◽  
Online Questionnaire ◽  
Content Type ◽  
The Individual ◽  
The Impact

Purpose – This paper aims to add to the understanding of knowledge sharing in online communities through an investigation of the relationship between individual participant’s motivations and management in open source software (OSS) communities. Drawing on a review of literature concerning knowledge sharing in organisations, the factors that motivate participants to share their knowledge in OSS communities, and the management of such communities, it is hypothesised that the quality of management influences the extent to which the motivations of members actually result in knowledge sharing. Design/methodology/approach – To test the hypothesis, quantitative data were collected through an online questionnaire survey of OSS web developers with the aim of gathering respondents’ opinions concerning knowledge sharing, motivations to share knowledge and satisfaction with the management of OSS projects. Factor analysis, descriptive analysis, correlation analysis and regression analysis were used to explore the survey data. Findings – The analysis of the data reveals that the individual participant’s satisfaction with the management of an OSS project is an important factor influencing the extent of their personal contribution to a community. Originality/value – Little attention has been devoted to understanding the impact of management in OSS communities. Focused on OSS developers specialising in web development, the findings of this paper offer an important original contribution to understanding the connections between individual members’ satisfaction with management and their motivations to contribute to an OSS project. The findings reveal that motivations to share knowledge in online communities are influenced by the quality of management. Consequently, the findings suggest that appropriate management can enhance knowledge sharing in OSS projects and online communities, and organisations more generally.

An Analysis on Human Resource Development Culture and Climate of Chemical Based Public Sector Enterprises in Kerala, India

2021 ◽  
Vol 2021 (6) ◽  
pp. 132-135
Author(s):  
Balakrishnan A ◽  
Dr. KVM Varambally
Keyword(s):  
Public Sector ◽  
Human Resource Development ◽  
Human Resource ◽  
Deep Structure ◽  
Positive Culture ◽  
Resource Development ◽  
The Individual ◽  
The Impact ◽  
Culture And Climate

The impact of Globalization creates a competitive horizon with new markets, new products, new mindsets, new competencies, and new ways of thinking about business. As an outcome of this, the market places become more complex, uncertain, competitive, and transformational. In this era, the major challenge faced by any organization is to maintain a peaceful as well positive culture and climate inside the organization. The human resource development climate of an organization plays a significant role in ensuring the competency, motivation, and development of its employees. Here the term climate denotes the quality of the internal environment. It influences morale and the attitudes of the individual toward his work and his environment. Culture refers to the deep structure of organizations, which is rooted in the values, beliefs, and assumptions held by organizational members. The study was aimed to analyze the Human Resource Development culture and climate of chemical-based public sector enterprises in Kerala. The results indicated that the Human Resource Development climate in an organization is average and the perception of employees regarding Human Resource Development culture and climate does not differs significantly based on age, job approval status, and qualification. But it differs significantly based on gender and experiences.

scholarly journals The Impact of the Quality Assessment of Optimal Assignment for Data Association in a Multitarget Tracking Context

2015 ◽  
Vol 15 (7) ◽  
pp. 88-98
Author(s):  
J. Dezert ◽  
A. Tchamova ◽  
P. Konstantinova
Keyword(s):  
Quality Assessment ◽  
Data Association ◽  
New Method ◽  
Multitarget Tracking ◽  
Belief Functions ◽  
Tracking Systems ◽  
Optimal Assignment ◽  
The Individual ◽  
The Impact

Abstract The main purpose of this paper is to apply and to test the performance of a new method, based on belief functions, proposed by Dezert et al. in order to evaluate the quality of the individual association pairings provided in the optimal data association solution for improving the performances of multisensor-multitarget tracking systems. The advantages of its implementation in an illustrative realistic surveillance context, when some of the association decisions are unreliable and doubtful and lead to potentially critical mistake, are discussed. A comparison with the results obtained on the base of Generalized Data Association is made.

scholarly journals ADAPTASI MODEL DELONE DAN MCLEAN YANG DIMODIFIKASI GUNA MENGUJI KEBERHASILAN IMPLEMENTASI APLIKASI OPERASIONAL BAITUL MAAL WAT TAMWIL (BMT) BAGI INDIVIDU PENGGUNA (Studi Empiris Pada BMT di Kota Semarang)

2016 ◽  
Vol 4 (2) ◽  
pp. 123
Author(s):  
Novita Anugrah Listiyana ◽  
Dedi Rusdi
Keyword(s):  
Path Analysis ◽  
User Satisfaction ◽  
Sampling Technique ◽  
Individual Performance ◽  
Quality System ◽  
Quality Of Information ◽  
Positive Direction ◽  
The Individual ◽  
The Impact

This study analyzed the relationship between humans as users of the system and application software as object an inseparable relationship. The purpose of this study was to analyze the effect of variable quality system to the perception of the quality system, the effect of perceived quality system and quality of information on the intensity of use and user satisfaction, and the influence of the intensity of use and user satisfaction of the impact of individual performance. This research is an empirical study using purposive sampling technique in data collection. Data were collected through  questionnaires to 39 BMT’s operational employees. Then, performed an analysis of the data obtained used path analysis. This included: testing hypotheses through path analysis. The results of tests performed using path analysis to get the results that each variable in the model of equation 4 had a coefficient with a positive direction. This means that the improvement of the quality of the system will be able to improve the quality of information for the individual impact of the use and satisfaction of employees through the use of the system.

scholarly journals Differential effects of early growth conditions on colour-producing nanostructures revealed through small angle X-ray scattering and electron microscopy

2020 ◽  
Vol 223 (18) ◽  
pp. jeb228387
Author(s):  
Katarzyna Janas ◽  
Anna Łatkiewicz ◽  
Andrew Parnell ◽  
Dorota Lutyk ◽  
Julia Barczyk ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Small Angle ◽  
Condition Dependence ◽  
Tail Feather ◽  
Blue Tit ◽  
X Ray ◽  
Stage Of Development ◽  
X Ray Scattering ◽  
Ray Scattering

ABSTRACTThe costs associated with the production and maintenance of colour patches is thought to maintain their honesty. Although considerable research on sexual selection has focused on structurally coloured plumage ornaments, the proximate mechanisms of their potential condition dependence, and thus their honesty, is rarely addressed, particularly in an experimental context. Blue tit (Cyanistes caeruleus) nestlings have ultraviolet (UV)–blue structurally coloured tail feathers, providing a unique opportunity for investigation of the causes of variation in their colour. Here, we examined the influence of early growing conditions on the reflectance and structural properties of UV–blue-coloured tail feathers of blue tit nestlings. We applied a two-stage brood size manipulation to determine which stage of development more strongly impacts the quality of tail feather colouration and microstructure. We used small-angle X-ray scattering (SAXS) and electron microscopy to characterise the nanoscale and microscale structure of tail feather barbs. Nestlings from the broods enlarged at a later stage of growth showed a sex-specific rectrix development delay, with males being more sensitive to this manipulation. Contrary to predictions, treatment affected neither the quality of the barbs’ nanostructures nor the brightness and UV chroma of feathers. However, at the microscale, barbs’ keratin characteristics were impaired in late-enlarged broods. Our results suggest that nanostructure quality, which determines the UV–blue colour in tail feathers, is not sensitive to early rearing conditions. Furthermore, availability of resources during feather growth seems to impact the quality of feather microstructure more than body condition, which is likely to be determined at an earlier stage of nestling growth.

Optimising the Growth of Few-Layer Graphene on Silicon Carbide by Nickel Silicidation

2013 ◽  
Vol 740-742 ◽  
pp. 121-124 ◽  
Author(s):  
Enrique Escobedo-Cousin ◽  
Konstantin Vassilevski ◽  
Toby Hopf ◽  
Nick G. Wright ◽  
Anthony O’Neill ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Solid Phase ◽  
Sample Surface ◽  
Device Fabrication ◽  
Solid Phase Epitaxy ◽  
X Ray ◽  
Graphene Films ◽  
Few Layer Graphene ◽  
The Impact

Few-layers graphene films (FLG) were grown by local solid phase epitaxy on a semi-insulating 6H-SiC substrate by annealing Ni films deposited on the Si and C-terminated faces of the SiC. The impact of the annealing process on the final quality of the FLG films is studied using Raman spectroscopy. X-ray photoelectron spectroscopy was used to verify the presence of graphene on the sample surface. We also demonstrate that further device fabrication steps such as dielectric deposition can be carried out without compromising the FLG films integrity.

scholarly journals Water Quality of Freshwater Ecosystems in a Temperate Climate

Water ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2643
Author(s):  
Piotr Klimaszyk ◽  
Ryszard Gołdyn
Keyword(s):  
Water Quality ◽  
Freshwater Ecosystems ◽  
Temperate Climate ◽  
Special Issue ◽  
Quality Of Water ◽  
Local Water ◽  
Water Ecosystems ◽  
The Individual ◽  
The Impact

Water is the substance that made life on Earth possible. It plays a key role in both the individual and population development of all species. Water is also a critical resource for humans as populations continue to grow and climate change affects global and local water cycles. Water is a factor limiting economic development in many regions of the world. Under these conditions, good water quality becomes an extremely important factor that determines its economic utility, including water supply, recreation, and agriculture. Proper water quality maintenance of freshwater ecosystems is also very important for preserving biodiversity. The quality of water depends on many factors, the most important of which are related to human impact on water ecosystems, especially the impact of various pollutants from municipal economy, industry and agriculture. Hydrotechnical changes, such as river damming, drainage processes and water transport between catchments also have a significant impact. Water quality is also dependent on the impact of natural conditions connected, e.g., with climate, catchment, water organisms and their interactions within the food-webs, etc. This Special Issue consists of fourteen original scientific papers concerning different problems associated with the water quality of freshwater ecosystems in a temperate climate. Most of the articles deal with the relations between water quality and the structure of ecosystem biocenoses. The conclusion of these articles confirms the fact that the deterioration of water quality has a direct impact on the quantitative and qualitative structure of biocenoses. This is accompanied by a decline in biodiversity and the disappearance of rare plant and animal species. They also draw attention to the particular importance of internal physical and chemical differentiation within the aquatic ecosystem, both in horizontal and vertical dimensions. The problem of ensuring proper ecological conditions and good quality of water in freshwater aquatic ecosystems is also raised, and methods for the restoration of water bodies are presented. The majority of the research presented in this Special Issue was carried out in Central Europe, and one of the papers concerns the area of West Africa—the edge of temperate climate zone.

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