scholarly journals Standardisation efforts of ISO/TC 261 “Additive Manufacturing”: 17th plenary meeting of ISO/TC 261 “Additive Manufacturing”

Author(s):  
Eujin Pei

AbstractThe main objective of ISO/TC 261 is to standardise the processes of additive manufacturing, the process chains (data, materials, processes, hard- and software, applications), test procedures, quality parameters, supply agreements, environment, health and safety, fundamentals and vocabularies. This section provides readers with news regarding standardisation efforts of ISO/TC 261.

2020 ◽  
Vol 5 (4) ◽  
pp. 317-318
Author(s):  
Eujin Pei

AbstractThe main objective of ISO/TC 261 is to standardise the processes of Additive Manufacturing, the process chains (Data, Materials, Processes, Hard- and Software, Applications), test procedures, quality parameters, supply agreements, environment, health and safety, fundamentals and vocabularies. The technical contents for those standards are developed in different Working Groups of ISO/TC 261. This section provides readers with news regarding standardisation efforts of ISO/TC 261.


Author(s):  
Rashmi Singh ◽  
Monika Saxena ◽  
Deeksha Sahay ◽  
Sujata Singh

Background: Azithromycin, being a very important antibiotic, is manufactured by different pharmaceutical companies and available in numerous brands. Therefore, it requires a quantitative evaluation and assessment of tablets chemical, physical and bioavailability properties.Methods: The physicochemical quality pararametrs like weight variation, size, hardness, friability, disintegration time and dissolution profile of three brands of azithromycin tablets were assessed by performing various test procedures according to established methods.Results: The different brands of tablets showed very slight variations in weight and size, not exceeding more than 5% of standard value. Similarly, hardness of all the brands was less than 5kg/f and friability ranged from 0.2 to 0.5%. All the brands tested disintegrated in <6 minutes and all the brands released >75% of the active ingredient within 45 minutes.Conclusions: All the physiochemical quality parameters of three brands of azithromycin tablets were found to be within the pharmacopeial specifications therefore all the brands were pharmaceutically and chemically equivalent and can be freely interchanged.


Geofluids ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-16 ◽  
Author(s):  
Filomena Canora ◽  
Giovanna Rizzo ◽  
Simona Panariello ◽  
Francesco Sdao

In this study, the hydrogeological characterization of the northern sector of the Lauria Mounts carbonate hydrostructure (southern Apennines, Basilicata region) has been carried out and the hydrochemical properties of different collected groundwater samples have been characterized. Several normal springs drain the hydrostructure, some of them characterized by high annual mean discharges. Groundwater samples were collected from different springs; many parameters such as pH, electrical conductivity, and total dissolved solids have been measured, and major (cations and anions) elements and stable isotopes have been analysed following standard test procedures. Other chemical characteristics were derived from the analysed quality parameters. The results elucidate that the main hydrogeochemical processes control the chemical content and assess the quality of the groundwater within the hydrostructure. The analyses highlight that the chemical compositions of groundwater are strongly influenced by the lithology, especially limestones and dolomitic limestones; they explain and confirm the hydrogeological setting of the system. The groundwater system displays light different geochemical signatures. The processes contributing to the concentrations of major ions depend primarily on carbonate dissolution. The analysis, in all studied groundwater samples, shows that the facies groundwater type is Ca–HCO3, bicarbonate is the dominant anion, and calcium is the dominant cation with appreciable magnesium concentrations. To identify the aquifer’s recharge areas, the environmental stable isotopes oxygen and hydrogen, deuterium, and 18O were analysed. The unaltered δ18O and δD signatures for the groundwater of the major springs allows identifying the recharge area of these emergencies at elevations ranging from 900 m to 1000 m (a.s.l.), pointing out the presence of deeper flow regime feeding of these springs. The groundwater sample isotopic characteristics of D and 18O suggest that most of the groundwater is recharged directly by infiltration in a high-permeability medium.


Author(s):  
Julius Schurb ◽  
Matthias Hoebel ◽  
Hartmut Haehnle ◽  
Harald Kissel ◽  
Laura Bogdanic ◽  
...  

Additive manufacturing and in particular Selective Laser Melting (SLM) are manufacturing technologies that can become a game changer for the production of future high performance hot gas path parts. SLM radically changes the design process giving unprecedented freedom of design and enabling a step change in part performance. Benefits are manifold, such as reduced cooling air consumption through more efficient cooling schemes, reduced emissions through better mixing in the combustion process and reduced cost through integrated part design. GE is already making use of SLM for its gas turbine components based on sound experience for new part production and reconditioning. The paper focuses on: a) Generic advantages of rapid manufacturing and design considerations for hot gas path parts b) Qualification of processes and additive manufacturing of engine ready parts c) SLM material considerations and properties validation d) Installation and validation in a heavy duty GT Additive Manufacturing (AM) of hot gas path components differs significantly from known process chains. All elements of this novel manufacturing route had to be established and validated. This starts with the selection of the powder alloy used for the SLM production and the determination of essential static and cyclic material properties. SLM specific design features and built-in functionality allow to simplify part assembly and to shortcut manufacturing steps. In addition, the post-SLM machining steps for engine ready parts will be described. As SLM is a novel manufacturing route, complementary quality tools are required to ensure part integrity. Powerful nondestructive methods, like 3D scanning and X-ray computer tomography have been used for that purpose. GE’s engine validation of SLM made parts in a heavy duty GT was done with selected hot gas path components in a rainbow arrangement including turbine blades with SLM tip caps. Although SLM has major differences to conventional manufacturing the various challenges from design to engine ready parts have been successfully mastered. This has been confirmed after the completion of the test campaign in 2015. All disassembled SLM components were found in excellent condition. Subsequent assessments of the SLM parts including metallurgical investigations have confirmed the good part condition.


2017 ◽  
Vol 207 ◽  
pp. 1176-1181 ◽  
Author(s):  
Margarita D. Bambach ◽  
Markus Bambach ◽  
Alexander Sviridov ◽  
Sabine Weiss

2017 ◽  
Vol 8 ◽  
pp. 52-58 ◽  
Author(s):  
Richard Girdwood ◽  
Martin Bezuidenhout ◽  
Philip Hugo ◽  
Pieter Conradie ◽  
Gert Oosthuizen ◽  
...  

Author(s):  
H N Hansen ◽  
J H Hattel ◽  
D B Pedersen ◽  
S Mohanty ◽  
S A Andersen ◽  
...  

2021 ◽  
Vol 14 (14) ◽  
pp. 124-131
Author(s):  
Khadka Bahadur Pal ◽  
Kiran Bishwakarma ◽  
Tarka Bahadur Chalaune ◽  
Durga Upadhaya ◽  
Tark Raj Joshi ◽  
...  

Freshwater contamination remains a challenging issue for the sustainable management of wetland ecosystems. This study aims to evaluate the water quality of Jhilmila Lake, Kanchanpur, Nepal by adopting standard test procedures, geochemical indices, and multivariate statistical analysis. The surface water samples were collected during the postmonsoon season in 2018 to assess the hydrochemical parameters such as pH, electrical conductivity (EC), total dissolved solids (TDS) and dissolved oxygen (DO), ammonium (NH4+ ), sodium (Na+), potassium (K+), calcium (Ca2+), magnesium (Mg2+), chloride (Cl-), sulphate (SO42-), nitrate (NO3-), phosphate (PO43-), bicarbonate (HCO3-) and total hardness (TH). The EC ranged from 162-190 µS/cm while TDS was 87-101 mg/L. The concentration of DO in the lake was in the range of 4.77-6.21 mg/L, indicated mild organic pollution. Moreover, the results revealed the moderate alkaline nature of water with the pattern of average ionic dominance of Ca2+>Na+>Mg2+ >K+>NH4+ for cations, and HCO3˗> Cl-> SO42- > NO3- > PO43- for anions. The principal component analysis demonstrated four major components indicating the association of EC, TDS, Ca2+, Mg2+, and HCO3- ; Na+ , PO43- and SO42-; NO3- and K+ ; and Cl- for PC1, PC2, PC3, and PC4, respectively exhibiting both the geogenic and anthropic origin. Overall, the Jhilmila Lake was less polluted, and all the measured water quality parameters were found within permissible limits in terms of drinking purposes. The findings of this study could help for the sustainable management of the lake by providing better insights into the water quality and hydrochemistry of the lake.


2021 ◽  
Vol 111 (11-12) ◽  
pp. 818-823
Author(s):  
Tobias Kelliger ◽  
Christoph Zachert ◽  
Daniel Schraknepper ◽  
Thomas Bergs

Durch additive Fertigung können Zerspanwerkzeuge beanspruchungsgerecht und individuell designt und gefertigt werden. Um das volle ökonomische und ökologische Potenzial dieser Werkzeuge auszuschöpfen, ist eine übergreifende Prozesskettenbetrachtung von der Konstruktion über die Fertigung bis zur spanenden Nachbearbeitung nötig. Dabei müssen übergreifende Lösungen und Gestaltungsrichtlinien entwickelt werden. &nbsp; Additive manufacturing enables an individual design and production of cutting tools that fulfills the requirements. However, the full economic and ecological potential can only be exploited by considering the entire process chain from design and production to post-processing. General solutions and design guidelines have to be developed.


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