scholarly journals QUALITY INDEX OF MULTI-DISC GRINDING PROCESS OF GRAINY BIOMASS

2019 ◽  
pp. 503-511
Author(s):  
Weronika Kruszelnicka ◽  
Adam Idzikowski ◽  
Katarzyna Markowska ◽  
Robert Kasner
Keyword(s):  
Quality Index ◽  
Grinding Process ◽  
Disc Grinding

scholarly journals Quality Index of Multi-Disc Grinding Process of Grainy Biomass

2019 ◽  
Vol 1 (1) ◽  
pp. 503-511 ◽  
Author(s):  
Weronika Kruszelnicka ◽  
Adam Idzikowski ◽  
Katarzyna Markowska ◽  
Robert Kasner
Keyword(s):  
Energy Consumption ◽  
Quality Assessment ◽  
Mathematical Description ◽  
Quality Index ◽  
Angular Speed ◽  
Process Quality ◽  
Size Reduction ◽  
Grinding Process ◽  
Grinding Parameters ◽  
Disc Grinding

Abstract The main aim of the grinding process is size reduction. For such formulated purpose of grinding, the particles dimensions after grinding process are the major quality determinant indicated in many works concerning size reduction. In this paper original quality index integrating size reduction and energy consumption in the grinding process was proposed. The aim of the study is to create method for grinding process quality assessment. The problem was formulated as a question: (1) is it possible to create mathematical description of grinding process quality? (2) what grinding parameters influence on the grinding quality index? To resolve the problem, original quality index was developed and experiment on a multi-disc mill was conducted. On the basis of obtained results it was found that discs angular speed affects the grinding process quality.

Analysis of the robotic disc grinding process

1992 ◽  
Vol 7 (2) ◽  
pp. 82-92 ◽  
Author(s):  
B. J. Ulrich ◽  
A. K. Srivastava ◽  
M. A. Elbestawi
Keyword(s):  
Grinding Process ◽  
Disc Grinding

Influence of Hand Disc Grinding on Surface Integrity of Nickel-Based Alloys: Numerical Approach

2013 ◽  
Author(s):  
Sawsen Youssef ◽  
Olivier Calonne ◽  
Hédi Hamdi
Keyword(s):  
Heat Flux ◽  
Surface Integrity ◽  
Ground Surface ◽  
Maximum Temperature ◽  
Grinding Wheel ◽  
Grinding Process ◽  
Feed Speed ◽  
Applied Forces ◽  
Grinding Power ◽  
Disc Grinding

For complex part geometry, hand grinding is one of finishing and super finishing process the most used in mechanical industry. Surface integrity is today one major concern for industrials. The surface integrity is defined by a set of important characteristics of ground surface as surface geometric parameters (roughness, …), mechanical behaviour of the subsurface (hardness, residual stress, …) and structural changes of the material in the near surface. High heat and pressure, high strain and strain rate observed during hand grinding process, strongly influence surface integrity. Therefore, the surface behaviour, in terms of resistance to corrosion and crack initiation depends on how the process was conducted. The purpose of this study is to understand the effects of thermal and mechanical plastic deformation induced on the surface of components. The action of the disc-grinding wheel on the workpiece is modelled by a moving heat flux on the surface. The challenge is to be able to find the shape and intensity of thermomechanical load entering the workpiece in accordance with the hand disc grinding process and taking into account specific parameters of the process. In a first part, a mechanical description of the action of the disc-wheel on the surface is proposed in order to develop an analytic formulation of the grinding power and the heat flux density. They are function of the disc-grinding wheel velocity, the feed speed and the applied forces. This expression is then used in a finite element modelling to perform thermomechanical simulations of the hand disc-grinding process. In a first stage, heating and cooling are computed. They give maximum temperature reached, temperature gradients and cooling kinematic. In a second stage, thermomechanical computation is conducted in order to compute residual stresses induced by this abrasion process. A discussion based on experimental results obtained by XRD method is then proposed and some local explanation are given on the way the material structure has changed leading to a structural hardening in the 50 first microns beneath the ground surface.

Homocysteine Levels Show Significant Differences among Mediterranean Dietary Quality Index Variables Compared to Folate and Vitamin B12 Status in Women

2015 ◽  
Vol 85 (3-4) ◽  
pp. 202-210 ◽  
Author(s):  
Ivona Višekruna ◽  
Ivana Rumbak ◽  
Ivana Rumora Samarin ◽  
Irena Keser ◽  
Jasmina Ranilović
Keyword(s):  
Mediterranean Diet ◽  
Diet Quality ◽  
Quality Index ◽  
Fruits And Vegetables ◽  
Reproductive Age ◽  
Dietary Quality ◽  
Vitamin B ◽  
Cross Sectional ◽  
Poor Diet ◽  
The Mediterranean

Abstract. Results of epidemiologic studies and clinical trials have shown that subjects following the Mediterranean diet had lower inflammatory markers such as homocysteine (Hcy). Therefore, the aim of this cross-sectional study was to assess female diet quality with the Mediterranean diet quality index (MDQI) and to determine the correlation between MDQI, homocysteine, folate and vitamin B12 levels in the blood. The study participants were 237 apparently healthy women (96 of reproductive age and 141 postmenopausal) between 25 and 93 years. For each participant, 24-hour dietary recalls for 3 days were collected, MDQI was calculated, and plasma Hcy, serum and erythrocyte folate and vitamin B12 levels were analysed. Total MDQI ranged from 8 to 10 points, which represented a medium-poor diet for the subjects. The strength of correlation using biomarkers, regardless of group type, age, gender and other measured parameters, was ranked from best (0.11) to worst (0.52) for olive oil, fish, fruits and vegetables, grains, and meat, in this order. Hcy levels showed the best response among all markers across all groups and food types. Our study shows significant differences between variables of the MDQI and Hcy levels compared to levels of folate and vitamin B12 in participants with medium-poor diet quality, as evaluated according to MDQI scores.

Quality of Governance at the Communal Level in Poland: an Exploratory Study of the Worst Performer Case From the Opolskie Province

2020 ◽  
Vol 21 (1) ◽  
pp. 22-55
Author(s):  
Bartosz Czepil
Keyword(s):  
Exploratory Study ◽  
Quality Index ◽  
Extreme Case ◽  
Quality Level ◽  
Case Method ◽  
Major Conclusion ◽  
Second Stage ◽  
Quality Of Governance ◽  
Governance Quality

The objective of this paper is an attempt to explain the determinants of the lowest governance quality level in one of the communes of the Opolskie Province, Poland. The first stage of the research consisted in developing a commune-level governance quality index in order to measure the quality of governance in the 60 communes of the Opolskie Province. Subsequently, the commune with the lowest score in the index was qualified for the second stage of the research which was based on the extreme case method. The major conclusion from the research is that the commune leader's governance style which allowed him to hold on to power for many terms of office was responsible for generating low governance quality. Furthermore, the low quality of governance was not only the effect of the governance style but also the strategy aimed at remaining in the commune leader office for many terms.

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