scholarly journals Definition of the aging process parameters for nickel hydroxide in the alkaline medium

2018 ◽  
Vol 2 (12 (92)) ◽  
pp. 54-60 ◽  
Author(s):  
Valerii Kotok ◽  
Vadym Kovalenko
Keyword(s):  
Alkaline Medium ◽  
Process Parameters ◽  
Nickel Hydroxide ◽  
Aging Process ◽  
Definition Of

scholarly journals Influence of Deep Rolling and Induction Hardening on Microstructure Evolution of Crankshaft Sections made from 38MnSiVS5 and 42CrMo4

2021 ◽  
Vol 76 (3) ◽  
pp. 175-194
Author(s):  
A. Fischer ◽  
B. Scholtes ◽  
T. Niendorf
Keyword(s):  
Process Parameters ◽  
Microstructure Evolution ◽  
Surface Hardening ◽  
Qualitative Evaluation ◽  
Induction Hardening ◽  
Deep Rolling ◽  
Automotive Components ◽  
Hardening Treatment ◽  
Steel Grades ◽  
Definition Of

Abstract In order to improve properties of complex automotive components, such as crankshafts, in an application-oriented way, several surface hardening treatments can be applied. Concerning the material performance the definition of adequate process parameters influences the resulting surface properties and, thus, the effectiveness of surface hardening treatments. To analyze most relevant process-microstructure-property relationships, the present paper reports results obtained by two different well-established surface hardening procedures, i. e. deep rolling as a mechanical treatment and induction hardening as a thermal treatment. For each hardening process widely used crankshaft steel grades, i. e. a medium carbon 38MnSiVS5 microalloyed steel and a quenched and tempered 42CrMo4 were selected and thoroughly characterized upon processing, using equal parameter settings. The results reveal that deep rolling in contrast to induction hardening proves to be a less sensitive surface layer treatment with regard to small differences in the initial microstructure, the chemical composition and the applied process parameters. Differences in microstructure evolution with respect to the applied surface hardening treatment are studied and discussed for the highly stressed fillet region of automotive crankshaft sections for all conditions. In this context, high-resolution SEM-based techniques such as EBSD and ECCI are proven to be very effective for fast qualitative evaluation of induced microstructural changes.

scholarly journals Analysis of the Downscaling Effect and Definition of the Process Fingerprints in Micro Injection of Spiral Geometries

Micromachines ◽  
2019 ◽  
Vol 10 (5) ◽  
pp. 335 ◽  
Author(s):  
Antonio Luca ◽  
Oltmann Riemer
Keyword(s):  
Correlation Analysis ◽  
Process Parameters ◽  
Cross Sections ◽  
Mass Production ◽  
Process Window ◽  
Response Variable ◽  
Process Indicators ◽  
Flow Length ◽  
Definition Of ◽  
Microinjection Moulding

Microinjection moulding has been developed to fulfil the needs of mass production of micro components in different fields. A challenge of this technology lies in the downscaling of micro components, which leads to faster solidification of the polymeric material and a narrower process window. Moreover, the small cavity dimensions represent a limit for process monitoring due to the inability to install in-cavity sensors. Therefore, new solutions must be found. In this study, the downscaling effect was investigated by means of three spiral geometries with different cross sections, considering the achievable flow length as a response variable. Process indicators, called “process fingerprints”, were defined to monitor the process in-line. In the first stage, a relationship between the achievable flow length and the process parameters, as well as between the process fingerprints and the process parameters, was established. Subsequently, a correlation analysis was carried out to find the process indicators that are mostly related to the achievable flow length.

scholarly journals Design Space and QbD Approach for Production of Drug Nanocrystals by Wet Media Milling Techniques

Pharmaceutics ◽  
2018 ◽  
Vol 10 (3) ◽  
pp. 104 ◽  
Author(s):  
Leena Peltonen
Keyword(s):  
Process Parameters ◽  
Design Space ◽  
Milling Process ◽  
Production Chain ◽  
Media Milling ◽  
Process Understanding ◽  
Poorly Soluble ◽  
Critical Process Parameters ◽  
Input Variables ◽  
Definition Of

Drug nanocrystals are nanosized solid drug particles, the most important application of which is the improvement of solubility properties of poorly soluble drug materials. Drug nanocrystals can be produced by many different techniques, but the mostly used are different kinds of media milling techniques; in milling, particle size of bulk sized drug material is decreased, with the aid of milling beads, to nanometer scale. Utilization of Quality by Design, QbD, approach in nanomilling improves the process-understanding of the system, and recently, the number of studies using the QbD approach in nanomilling has increased. In the QbD approach, the quality is built into the products and processes throughout the whole production chain. Definition of Critical Quality Attributes, CQAs, determines the targeted final product properties. CQAs are confirmed by setting Critical Process Parameters, CPPs, which include both process parameters but also input variables, like stabilizer amount or the solid state form of the drug. Finally, Design Space determines the limits in which CPPs should be in order to reach CQAs. This review discusses the milling process and process variables, CPPs, their impact on product properties, CQAs and challenges of the QbD approach in nanomilling studies.

Study on Two-Step Aging Technology of 6082 Aluminum Bumper

2018 ◽  
Vol 764 ◽  
pp. 245-251
Author(s):  
Bei Ming Zhao ◽  
Miao Hu ◽  
Jun Zhu ◽  
Zhen Yu Han ◽  
Hou Qing Sun ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Process Parameters ◽  
Aging Temperature ◽  
Aging Process ◽  
Production Efficiency ◽  
Holding Time ◽  
Second Stage ◽  
Main Factors ◽  
6082 Aluminum Alloy

The influence of four parameters of two-step aging on the mechanical properties of 6082 aluminum alloy bumper was studied by orthogonal test. The results show that compared with the single stage aging, the two-step aging process can reduce the aging time and improve the production efficiency under the premise of the mechanical properties of the bumper meet the requirements. Among the four aging process parameters, the second stage aging temperature and holding time are the main factors that affect the final results, while the first stage aging temperature and holding time are secondary factors. The most suitable aging process parameters for the 6082 aluminum alloy bumper is (150 °C, 2 h) + (190 °C, 2.5 h). After two-step aging, the grain of the aluminum bumper is small and evenly distributed, leading to good mechanical properties. The generalized experiment shows that the application of the two-step aging process still has some limitations and needs to be further optimized and perfected.

Perspectives on the Continuity Perspective

1982 ◽  
Vol 14 (2) ◽  
pp. 97-115 ◽  
Author(s):  
Judith H. Fox
Keyword(s):  
Old Age ◽  
Aging Process ◽  
Comparable Data ◽  
Conceptual Definition ◽  
Definition Of

This paper explores the strengths and limitations of the continuity perspective on aging. First, current usages of the concept are delineated. Then available literature is reviewed for evidence that continuity is in fact characteristic of the aging process and for indications that it is positively related to morale in old age. While lack of comparable data makes conclusions somewhat tentative, it appears that discontinuity is as characteristic of aging as continuity and that continuity may actually be maladaptive in many cases. Components of a conceptual definition of continuity are discussed, and suggestions are made for operationalization and more rigorous investigation of the concept.

A Comprehensive Study of Auxiliary Arrangements for Attaining Omnidirectionality in Additive Manufacturing Machine Tools

2020 ◽  
Vol 143 (5) ◽  
Author(s):  
Ambrish Singh ◽  
Seema Negi ◽  
Sajan Kapil ◽  
K. P. Karunakaran ◽  
Manas Das
Keyword(s):  
Additive Manufacturing ◽  
Process Parameters ◽  
Directional Sensitivity ◽  
Delivery Vector ◽  
Design Variables ◽  
Fixed Set ◽  
Definition Of ◽  
Am Processes ◽  
Sheer Number

Abstract Anisotropy and omnidirectionality are the two most significant impediments to the growth of additive manufacturing (AM). While anisotropy is a property of the part, omnidirectionality is a characteristic of the machine tool. Omnidirectionality, implying invariance in AM processes with the goal of minimizing variations in material and geometric properties of the as-built parts, is often ignored during systems and process design. Disregard to directional sensitivity, which in some cases are inherent to the process (and/ or system), inadvertently changes the process parameter in-situ consequently, producing parts with non-uniform and often erratic properties. AM, attributing to its sheer number of processing variables, is especially susceptible to this subtle, yet significant system property. While some AM platforms, due to their nature of part production, are inherently omnidirectional, others require additional setup to ensure the same. Having an omnidirectional AM platform ensures that the parts are fabricated with process variables that are equally sensitive in all directions. In most AM systems, given a fixed set of process parameters, the spatial orientation of fusion (or joining) source vector, feedstock-delivery vector, and travel direction vector relative to each other governs omnidirectionality. Inconsistency or change in orientation of these three vectors results in non-uniform part properties and variations in geometric dimensions. Therefore, AM systems have to be omnidirectional to improve part performance and promote industrial acceptance. This paper, through a formal definition of omnidirectionality, analyses these three vectors individually along with their interplay with other process parameters and design variables.

scholarly journals Data-science driven autonomous process optimization

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Melodie Christensen ◽  
Lars P. E. Yunker ◽  
Folarin Adedeji ◽  
Florian Häse ◽  
Loïc M. Roch ◽  
...  
Keyword(s):  
Process Optimization ◽  
Process Parameters ◽  
Data Science ◽  
Product Yield ◽  
Phosphine Ligands ◽  
High Yield ◽  
Molecular Feature ◽  
Free Exploration ◽  
Definition Of

AbstractAutonomous process optimization involves the human intervention-free exploration of a range process parameters to improve responses such as product yield and selectivity. Utilizing off-the-shelf components, we develop a closed-loop system for carrying out parallel autonomous process optimization experiments in batch. Upon implementation of our system in the optimization of a stereoselective Suzuki-Miyaura coupling, we find that the definition of a set of meaningful, broad, and unbiased process parameters is the most critical aspect of successful optimization. Importantly, we discern that phosphine ligand, a categorical parameter, is vital to determination of the reaction outcome. To date, categorical parameter selection has relied on chemical intuition, potentially introducing bias into the experimental design. In seeking a systematic method for selecting a diverse set of phosphine ligands, we develop a strategy that leverages computed molecular feature clustering. The resulting optimization uncovers conditions to selectively access the desired product isomer in high yield.

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