scholarly journals Understanding Heterogeneity of a Slag-Derived Weathered Material: The Role of Automated SEM-EDS Analyses

Minerals ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 513 ◽  
Author(s):  
Anna Pietranik ◽  
Jakub Kierczak ◽  
Rafał Tyszka ◽  
Bernhard Schulz
Keyword(s):  
Toxic Elements ◽  
Sem Analysis ◽  
Heavy Mineral ◽  
Polished Section ◽  
Metal Release ◽  
Secondary Phases ◽  
Mineral Particles ◽  
Slag Heap ◽  
Materials Used

Slag heaps over years may evolve into complexly weathered zones, which are a challenging material for analyses as they contain phases from numerous sources and at different stages of weathering. However, the weathered zones are important parts of slag heaps, because they contain both primary and secondary phases enriched in metal(oid)s that may become soluble under specific conditions. The weathering reactions related to metal release or precipitation may be recorded in a heavy mineral fraction as the fraction contains predominately minerals with elevated toxic elements concentrations. Therefore, an automated SEM analysis on a polished section of included heavy mineral particles was applied in this paper for a rapid recognition of phases in a complex setting and their classification into detrital, primary and secondary phases. The approach was applied to a slag heap in Świętochłowice (Upper Silesia, Poland) and it consisted of analyzing magnetic and non-magnetic heavy mineral fractions from three distinct horizons noted A, B and C. Materials had been previously interpreted as being sourced from the heap itself (lowermost horizon C) and from artificially added materials used later for superficial site remediation (upper horizons A and B). Instead, automated SEM analysis demonstrated that horizon C is derived from the slag heap weathering, horizon B is derived predominately from the artificially added materials, whereas horizon A is a mixture of the B and C horizons. Additionally, when slag particles in horizons A and C are compared, the lowermost horizon C contains more slag-derived secondary phases, whereas horizon A contains more primary slag phases. Therefore, horizon A remains the most prone to releasing toxic elements because, considering its position as the uppermost horizon, it can be submitted to climatic solicitation (fast water circulation).

Calculations used for assessment of rapid maxillary expansion

ORL ro ◽  
2016 ◽  
Vol 1 (1) ◽  
pp. 24-26
Author(s):  
Ruxandra Bartok ◽  
Bogdan Dimitriu Dimitriu ◽  
Constantin Vârlan ◽  
Radu Stanciu ◽  
Georgiana Moldoveanu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Elasticity Modulus ◽  
Rapid Maxillary Expansion ◽  
Laboratory Animals ◽  
Maxillary Expansion ◽  
Literature Reference ◽  
Bone Changes ◽  
Upper Jaw ◽  
Materials Used

Rapid maxillary expansion is defined as the release of medio-palatine suture using an orthopedic forces. The role of this procedure is to expand  the upper jaw in order to achieve the  broadening of the upper arch. This study was initiated to quantify the effects of disjunction and post- treatment bone changes, after an adequate contention which lasted for three weeks. This study  is  carried on laboratory animals (common breed rabbit) to determine tensile strength and the elasticity modulus of  biological materials  used in orthdodontics. The results of the study are consistent with those reported in the literature reference.  

scholarly journals Biofilm forming ability of Sphingomonas paucimobilis isolated from community drinking water systems on plumbing materials used in water distribution

2017 ◽  
Vol 15 (6) ◽  
pp. 942-954 ◽  
Author(s):  
Parul Gulati ◽  
Moushumi Ghosh
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Biofilm Formation ◽  
Water Distribution ◽  
Sem Analysis ◽  
Sphingomonas Paucimobilis ◽  
Simulated Distribution ◽  
Flow Through ◽  
Materials Used ◽  
Biofilm Development

Sphingomonas paucimobilis, an oligotroph, is well recognized for its potential for biofilm formation. The present study explored the biofilm forming ability of a strain isolated from municipal drinking water on plumbing materials. The intensity of biofilm formation of this strain on different plumbing materials was examined by using 1 × 1 cm2 pieces of six different pipe materials, i.e. polyvinyl chloride (PVC), polypropylene (PP), polyethylene (PE), aluminium (Al), copper (Cu) and rubber (R) and observing by staining with the chemical chromophore, Calcofluor. To understand whether biofilm formation occurs under flow through conditions, a laboratory-scale simulated distribution system, comprised of the above materials was fabricated. Biofilm samples were collected from the designed system at different biofilm ages (10, 40 and 90 hours old) and enumerated. The results indicated that the biofilm formation occurred on all plumbing materials with Cu and R as exceptions. The intensity of biofilm formation was found to be maximum on PVC followed by PP and PE. We also demonstrated the chemical chromophore (Calcofluor) successfully for rapid and easy visual detection of biofilms, validated by scanning electron microscope (SEM) analysis of the plumbing materials. Chlorination has little effect in preventing biofilm development.

Pots on mats: mat-impressed salt-extraction pottery at Chalcolithic Provadia-Solnitsata, Bulgaria

Antiquity ◽  
2021 ◽  
pp. 1-16
Author(s):  
Mila Andonova ◽  
Vassil Nikolov
Keyword(s):  
Material Culture ◽  
Large Scale ◽  
Raw Materials ◽  
Salt Production ◽  
Production And Consumption ◽  
Late Chalcolithic ◽  
South Eastern Europe ◽  
Materials Used ◽  
The Relationship

Evidence for both basket weaving and salt production is often elusive in the prehistoric archaeological record. An assemblage of Middle–Late Chalcolithic pottery from Provadia-Solnitsata in Bulgaria provides insight into these two different technologies and the relationship between them. The authors analyse sherds from vessels used in large-scale salt production, the bases of which bear the impression of woven mats. This analysis reveals the possible raw materials used in mat weaving at Provadia-Solnitsata and allows interpretation of the role of these mats in salt production at the site. The results illustrate how it is possible to see the ‘invisible’ material culture of prehistoric south-eastern Europe and its importance for production and consumption.

The influence of thickness of CrN coating on the durability of hot forging dies

2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Jerzy Smolik
Keyword(s):  
Coating Thickness ◽  
Nitrided Layer ◽  
Hot Forging ◽  
Sem Analysis ◽  
Internal Stresses ◽  
Main Role ◽  
Hybrid Layer ◽  
Crn Coating ◽  
Forging Process

AbstractThis article presents results which enabled the determination of the role of CrN coating and the influence of its thickness on the effectiveness of hybrid layer “nitrided layer / CrN coating” in the process of increasing the durability of forging dies. Dies coated with hybrid layers “nitrided layer / CrN coating” with various CrN coating thickness were — after different maintenance periods — subjected to metallographic testing, 3D shape testing and SEM analysis. Hardness distribution was also determined. The obtained results revealed that for all tested dies, independently from CrN coating thickness, the main mechanisms of their destruction was mechanical and thermal fatigue, and plastic deformation. It has been shown that the main role of CrN coating in the hybrid layer ”nitrided layer / PVD coating” is to counteract a high temperature influence the source of which is forging on die material. In order to do so the CrN coating should be characterized by a considerably lower thermal conductivity coefficient to steel and low hardness so that it can efficiently resist fatigue processes in the forging process. Based on testing conducted by means of the sin 2 φ method, it was revealed that internal stresses are vitally important for CrN coating for fatigue resistance of hybrid layer ”nitrided layer / CrN coating” during the forging process.

scholarly journals Peran Levers of Control Terhadap Hubungan Antara Perencanaan Strategis dan Kinerja UMKM

2019 ◽  
Vol 1 (3) ◽  
pp. 166-174
Author(s):  
Praja Hadi Saputra ◽  
Hamid Bone ◽  
Indah Permatasari
Keyword(s):  
Control System ◽  
Sem Analysis ◽  
Management Control ◽  
Strategy Formulation ◽  
Management Control System ◽  
Controlling System ◽  
Mediation Hypothesis ◽  
Indirect Relationship ◽  
Levers Of Control

This study investigates the role of levers-of-control (LOC) based controlling system in the strategy formulation and MSME performance relationship in Samarinda. Through a survey conducted on the leadership (controller) of MSMEs in Samarinda City, this study evidenced the role of management control systems in the strategy formulation and MSME performance relationship. Of the 49 responses of MSME leaders, processed using PLS-SEM analysis, this study provided empirical evidence that the strategy formulation had a positive relationship with MSME performance. In addition, the indirect relationship between the two (mediation) through LOC-based management system supported the mediation hypothesis that the LOC-based management control system affects the strategy formulation and MSME performance relationship. In other words, it can be concluded that the management control system can increase the strategy formulation role that leads to MSME performance betterment.  

scholarly journals Application of immobilized mycelium-based pellets for the removal of organochlorine compounds: a review

2021 ◽  
Author(s):  
J. C. V. Pereira ◽  
M. P. Serbent ◽  
E. Skoronski
Keyword(s):  
Wastewater Treatment Plants ◽  
Cost Effective ◽  
Field Studies ◽  
Organochlorine Compounds ◽  
Environmental Persistence ◽  
Factors Affecting ◽  
Materials Used ◽  
Immobilization Techniques ◽  
Enzymatic Machinery

Abstract Organochlorines have diverse structures and applications and are included in the list of persistent organic pollutants (POPs) due to their toxicity and environmental persistence. The reduced capacity of conventional wastewater treatment plants to remove these compounds encourages the development of cost-effective and efficient remediation approaches. Fungal biotechnology can contribute to the development of these technologies through their enzymatic machinery but faces several drawbacks related to the use of dispersed mycelium. In this sense, investigations concerning the degradation of organochlorines using immobilized fungi demonstrated an increase in contaminants removal efficiency compared with degradation by free cells. Despite this interest, the mechanisms of immobilized fungi have not been comprehensively reviewed. In this paper, recent advances of laboratory and field studies in organochlorine compounds removal by fungi were reviewed, focusing on the role of immobilization techniques. Firstly, the mechanisms of organochlorines bioconversion by fungi and the factors affecting enzyme activity are elucidated and discussed in detail. Then, the main targeted compounds, fungi, technics, and materials used for immobilization are discussed, as well as their advantages and limitations. Furthermore, critical points for future studies of the fungi immobilization for organochlorines removal are proposed.

scholarly journals Bladder Substitution: The Role of Tissue Engineering and Biomaterials

Processes ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 1643
Author(s):  
Martina Casarin ◽  
Alessandro Morlacco ◽  
Fabrizio Dal Moro
Keyword(s):  
Tissue Engineering ◽  
Urinary Diversion ◽  
Mucus Production ◽  
Reconstructive Procedures ◽  
Suitable Material ◽  
Orthotopic Urinary Diversion ◽  
Bladder Substitution ◽  
Materials Used ◽  
Bowel Segments

Tissue engineering could play a major role in the setting of urinary diversion. Several conditions cause the functional or anatomic loss of urinary bladder, requiring reconstructive procedures on the urinary tract. Three main approaches are possible: (i) incontinent cutaneous diversion, such as ureterocutaneostomy, colonic or ileal conduit, (ii) continent pouch created using different segments of the gastrointestinal system and a cutaneous stoma, and (iii) orthotopic urinary diversion with an intestinal segment with spherical configuration and anastomosis to the urethra (neobladder, orthotopic bladder substitution). However, urinary diversions are associated with numerous complications, such as mucus production, electrolyte imbalances and increased malignant transformation potential. In this context, tissue engineering would have the fundamental role of creating a suitable material for urinary diversion, avoiding the use of bowel segments, and reducing complications. Materials used for the purpose of urinary substitution are biological in case of acellular tissue matrices and naturally derived materials, or artificial in case of synthetic polymers. However, only limited success has been achieved so far. The aim of this review is to present the ideal properties of a urinary tissue engineered scaffold and to examine the results achieved so far. The most promising studies have been highlighted in order to guide the choice of scaffolds and cells type for further evolutions.

Young Adults' Knowledge of Politics: Evaluating the Role of Socio-Cognitive Variables Using Structural Equations

2011 ◽  
Vol 14 (1) ◽  
pp. 183-194 ◽  
Author(s):  
Silvina Brussino ◽  
Leonardo Medrano ◽  
Patricia Sorribas ◽  
Hugo H. Rabbia
Keyword(s):  
Young Adults ◽  
Structural Equation ◽  
Political Knowledge ◽  
Political Efficacy ◽  
Sem Analysis ◽  
Education Level ◽  
Structural Equations ◽  
The Political ◽  
Cognitive Variables

The aim of this study was to create an explanatory model that allows analyzing the predictive power of a set of variables related to political knowledge; more specifically, to analyze the relationship between the education level of young adults and the variables, interest in politics and internal political efficacy. We also analyzed the combined relationship between these variables, together with age, and political knowledge. We worked with a sample group of 280 young adults between the ages of 18-30 from the city of Córdoba (Argentina). The data was subjected to a structural equation modelling SEM analysis, which allowed for the corroboration of the following hypotheses: the higher the education level, the more the interest in politics; the higher the education level, the better the perception of internal political efficacy; the higher the education level, the more the political knowledge; the more the interest in politics, the more the political knowledge; and the better the perception of internal political efficacy, the more interest in politics. Moreover, the following hypotheses could not be verified: the older an individual, the more the political knowledge; and the better the perception of internal political efficacy, the more the political knowledge. The model obtained allows for discussion of the explanatory value of these socio-cognitive variables.

Role of affect in marketplace rumor propagation

2019 ◽  
Vol 37 (6) ◽  
pp. 631-644
Author(s):  
Subin Sudhir ◽  
Anandakuttan B. Unnithan
Keyword(s):  
Negative Affect ◽  
Positive Affect ◽  
Cognitive Appraisal ◽  
Sem Analysis ◽  
Appraisal Theory ◽  
Content Type ◽  
Rumor Propagation ◽  
Sharing Behavior ◽  
Significant Factors

Purpose Rumors about products and brands are common occurrence in the marketplace. Often these rumors are shared among consumers using the word of mouth channel. The spread of these rumors is fast and can lead to significant consequences to products and brands. The purpose of this paper is to explore the dynamics of such rumor sharing behavior among consumers. Specifically, this paper investigates the role of positive affect and negative affect in rumor sharing behavior. Three key rumor characteristics (valence, involvement and credibility) are explored as antecedents to positive affect and negative affect. Design/methodology/approach The paper collects data from 236 respondents using Amazon MTurk, and conducts a PLS–SEM analysis to explore the role of positive affect and negative affect in rumor sharing contexts. Findings Both positive affect and negative affect were found to be significant factors leading to rumor sharing, furthermore positive affect was found to have a stronger influence on rumor sharing as compared to negative affect. The study also delineates the role of valence, involvement and credibility in rumor sharing scenarios, all of which have a strong role in shaping positive affect and negative affect. Originality/value The study is novel in using cognitive appraisal theory to illustrate the formation of positive affect and negative affect in rumor encounters. The study conclusively illustrates the role of cognitive appraisal and emotional experiences in the rumor propagation context, and advances the marketing scholarship’s understanding significantly.

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