scholarly journals Optimization of 3d-Printer Enclosure Environment

2021 ◽  
Author(s):  
Thomas J. May ◽  
Babak Eslami ◽  
Kamran Fouladi
Keyword(s):  
Ultimate Strength ◽  
Experimental Testing ◽  
Elastic Behavior ◽  
Print Quality ◽  
3D Printer ◽  
3 Dimensional ◽  
3D Printed ◽  
Computational Fluid Dynamics Cfd

Abstract Additive manufacturing has become a widely utilized process in industrial, academic, and household applications. Previous studies have demonstrated that non-optimum humidity conditions can adversely impact the print quality of parts printed from plastic filaments by changing their mechanical properties, such as elastic modulus and ultimate strength. This study utilized a computational fluid dynamics (CFD) approach and experimental testing to design a system that yields a more uniform humidity distribution in a 3-dimensional (3D) printer printing region. The study resulted in an optimized enclosure with significantly higher relative humidity (RH) uniformity in the print volume. The simulations predicted that the optimized enclosure would improve the uniformity by about 65%, while experimental testing pointed to even more significant improvement at about 75%. As a case study, tensile testing of 3D printed specimens made from NinjaFlex© filamenets under the optimum environmental conditions showed 11% higher ultimate strength and more elastic behavior than specimens printed using the baseline model.

Additive Manufacturing With Ceramics

2020 ◽  
Author(s):  
Kjetil Cline ◽  
Andrew LaFlam ◽  
Logan Smith ◽  
Margaret Nowicki ◽  
Nicholas Ku
Keyword(s):  
Additive Manufacturing ◽  
Body Armor ◽  
Print Quality ◽  
3D Printer ◽  
Current Design ◽  
3D Printed ◽  
To Receive ◽  
Boron Carbide B4c ◽  
Team Concept

Abstract The purpose of this project is to design a device that improves the performance of a ceramic additive manufacturing (AM) 3D printer constructed by Army Research Labs (ARL). ARL modified a standard LulzBot Taz 6 3D printer to print a ceramic slurry mixture of Boron Carbide (B4C) and Silicon Carbide (SiC) instead of plastic filament. Since these compounds are often used in body armor, ARL has been observing the effects on properties when these components are 3D printed. The current printer utilizes an auger in the print head to receive and mix the B4C and SiC slurries and extrude the combined slurry out of the print nozzle. The current design is limited in its ability to thoroughly mix the slurries during the printing process. Therefore, team Concept Creators has designed an improved auger that will increase the mixedness of the slurries, thus increasing the print quality of the composite specimen.

A Study on the Performance of Stratified Air Conditioning Design in Assembly Halls – A Case Study at the Dazhi Cultural Center in Taiwan

2013 ◽  
Vol 368-370 ◽  
pp. 599-602 ◽  
Author(s):  
Ian Hung ◽  
Hsien Te Lin ◽  
Yu Chung Wang
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Indoor Air ◽  
Air Conditioning ◽  
Cfd Simulation ◽  
Indoor Temperature ◽  
Cultural Center ◽  
Computational Fluid Dynamics Cfd

This study focuses on the performance of air conditioning design at the Dazhi Cultural Center and uses a computational fluid dynamics (CFD) simulation to discuss the differences in wind velocity and ambient indoor temperature between all-zone air conditioning design and stratified air conditioning design. The results have strong implications for air conditioning design and can improve the indoor air quality of assembly halls.

scholarly journals The Impact of Slicing Softwares on the Mechanical Properties of 3D Printed Parts

2020 ◽  
Vol 9 (2) ◽  
pp. 487-494
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
3D Printer ◽  
Stl File ◽  
3D Printed ◽  
Intersection Curves ◽  
The Impact

“Slicing tool” or “Slicing Software” computes the intersection curves of models and slicing planes. They improve the quality of the model being printed when given in the form of STL file. Upon analyzing a specimen that has been printed using two different slicing tools, there was a drastic variation on account of the mechanical properties of the specimen. The ultimate tensile strength and the surface roughness of the material vary from one tool to another. This paper reports an investigation and analysis of the variation in the ultimate tensile strength and the surface roughness of the specimen, given that the 3D printer and the model being printed is the same, with a variation of usage of slicing software. This analysis includes ReplicatorG, Flashprint as the two different slicing tools that are used for slicing of the model. The variation in the ultimate tensile strength and the surface roughness are measured and represented statistically through graphs. An appropriate decisive conclusion was drawn on the basis of the observations and analysis of the experiment on relevance to the behavior and mechanical properties of the specimen.

scholarly journals Evaluation of Seabed Stability and Scour Control Around Subsea Gravity Protection Structures

2010 ◽  
Author(s):  
Richard J. S. Whitehouse ◽  
Carlos Lam ◽  
Stephen Richardson ◽  
Peter Keel
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
North Sea ◽  
Cfd Analysis ◽  
Cfd Model ◽  
3 Dimensional ◽  
Computational Fluid Dynamics Cfd ◽  
The Uk ◽  
Study Application

Results from an advanced 3-dimensional Computational Fluid Dynamics (CFD) model have proven to form an effective basis on which to design stable and scour resistant subsea structures in areas of seabed which are prone to scouring. A case study application from the UK sector of the southern North Sea is presented to demonstrate the benefits of the CFD analysis.

scholarly journals A LITHOPHANE MODEL MAKING PROCESS TO 3D PRINTERS

2020 ◽  
Author(s):  
Siddavatam Rammohan Reddy
Keyword(s):  
Melting Point ◽  
Acrylonitrile Butadiene Styrene ◽  
3D Models ◽  
3D Printer ◽  
Layer By Layer ◽  
3 Dimensional ◽  
3D Objects ◽  
3D Printers ◽  
3D Printed ◽  
Butadiene Styrene

This paper focuses on to convert photographs into embossed 3D models and then bring them to life using a 3D printer. A Lithophane is a 3-dimensional generation of a 2-dimensional image and 3D representation of a photo can be seen only when it is illuminated from behind. Turning images into 3D objects give us more feeling and literally adds a new dimension. The lithophane can be manufactured by the way of an automated additive manufacturing process, such as 3-D printing. lithophanes are a simple way to enhance your favourite photos. 3D printed photos also known as 3D Printed lithophanes, are an extremely unique and creative application. The process adopted in lithophane is FDM technology, in which different the materials like PLA (polylactic acid), ABS (acrylonitrile butadiene styrene), etc. By heating the filament material to its melting point and it is deposited layer by layer. Combination of many layers will give us a final 3D Printed model.

PECULIARITIES OF USING THE CASE-STUDY TECHNIQUE IN STUDYING EASTERN LANGUAGES

2018 ◽  
pp. 54-57
Author(s):  
Olga Plakhotnik ◽  
Oleksandra Nazarenko
Keyword(s):  
Social Skills ◽  
Cognitive Processes ◽  
Experimental Testing ◽  
Concrete Case ◽  
Learning Skills ◽  
The Future ◽  
Quality Of Learning ◽  
Senior Students

The article is about the peculiarities of using efficient technologies of study in higher educational establishments and about the efficiency of using the case-study technique in studying eastern languages and Korean in particular. The notion, content, key elements and the usage of the case-study technique are considered as well as underlined the main stages of using this technique. It is emphasized that teachers determingly need to learn active and interactive forms and technologies of conducting lessons, such as games, trainings, cases, game projecting, creative techniques and many other devices which develop student base competences and metacompetences. These techniques shape skills and abilities and are necessary for the future profession and create a background for a psychological preparedness to implement them into actual and practical side of a work through gained skills and abilities. The authors emphasize that the consiquent analysis of a methods of organising the case-study technique can ocasionally be met in methodic special literature; as well as the amplyfication of the mechanisms of its influence on the cognitive processes of a particular personality and how such a technique boosts the development of communicative and other social skills. That is why the authors outline the main stages of implementing the case-study technique in studying Eastern languages. It is suggested to pay your attention to what concrete case is the most appropriate for studying Korean and/ or other eastern languages. The authors underline the main advantages of the technique and the conditions of using it successfully in the process of study. The necessity of using the case-study technique will provide the posibility to lift up the quality of learning skills and abilities, as well as adequate special competences. As an outcome of an experimental testing was found out the level of interest of senior students to their lessons, in the process of organising which, the case-study technique is used.

Fused Deposition Modeling With Added Vibrations: A Parametric Study on the Accuracy of Printed Parts

2019 ◽  
Author(s):  
Joseph Dei Rossi ◽  
Ozgur Keles ◽  
Vimal Viswanathan
Keyword(s):  
Engineering Students ◽  
Fused Deposition Modeling ◽  
Maximum Amplitude ◽  
Disruptive Technology ◽  
Print Quality ◽  
Optimum Level ◽  
Fused Deposition ◽  
3D Printers ◽  
3D Printed

Abstract Additive manufacturing is a potentially disruptive technology with a rapidly growing market. The recent development of RepRap style 3D printers has made this technology available to the public at a low cost. While these 3D printers are being used for a variety of purposes, many mechanical engineering students use them for prototyping in their projects. The quality of the 3D printed parts has been a concern in such cases. There are many variables within the operation of these printers that can be varied to obtain optimum print quality. This study explores the use of externally induced mechanical vibrations to the nozzle tip as a potential method to improve the quality of 3D printed parts. Induced vibration is expected to decrease the porosity of printed parts and improve the cohesion between print beads, ultimately improving their mechanical properties. The objective is to understand the positional accuracy of the prints with the added vibration and then to determine the optimum level of vibration to achieve best quality prints. For the study, the extruder filament is replaced with a pointed-tip pen that can mark the exact location where the printer delivers the material. A comparison between the locations marked by the pen with and without vibrations shows that the errors induced by the added vibration are not significantly different from those caused by the uncertainties of the printer itself. Further, this study also explores the optimum motor speeds to achieve a uniform distribution of material and determines medium motor speeds that provide maximum amplitude of vibration which are more desirable for a uniform infill.

scholarly journals The advantages of combining 3D printing with turning process. Case study

2021 ◽  
Vol 343 ◽  
pp. 02010
Author(s):  
Dan Claudiu Negrău ◽  
Gavril Grebenisan ◽  
Ion Cosmin Gherghea ◽  
Daniel Anton
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Lead Time ◽  
Dimensional Accuracy ◽  
3D Printer ◽  
Technological Properties ◽  
Turning Process ◽  
Finishing Process

The paper presents a case study which the additive manufacturing technology is combined with finishing process by cutting operations (turning) for manufacturing a part. The part was manufactured through additive manufacturing, using a 3D printer and the and the finishing process is performed by a lathe, resulting in technological properties and the corresponding dimensional accuracy. The research paper also contains the analysis of the roughness and other properties of the material from which the final part will be made. The manufactured part will be used as a support for the blades of a fan during the assembly process, which emphasizes that a part obtained by additive manufacturing (3D printing) can replace a part obtained by casting or fabrication by total cutting. In conclusion, obtaining the manufactured part by combining the two manufacturing processes, the lead time and the production cost has been significantly reduced, while the quality of the obtained product also increased, obtaining a very good roughness.

Spot-scan imaging of ice-embedded catalase crystal on a slow-scan CCD camera in a 400-kV electron cryomicroscope

1994 ◽  
Vol 52 ◽  
pp. 98-99
Author(s):  
Wah Chiu ◽  
Michael Sherman ◽  
Jaap Brink
Keyword(s):  
Electron Diffraction ◽  
Ccd Camera ◽  
Protein Crystal ◽  
Modulation Transfer ◽  
Measured Intensity ◽  
3 Dimensional ◽  
Dimensional Reconstruction ◽  
Diffraction Patterns ◽  
Complex Crystal

In protein electron crystallography, both low dose electron diffraction patterns and images are needed to provide accurate amplitudes and phases respectively for a 3-dimensional reconstruction. We have demonstrated that the Gatan 1024x1024 model 679 slow-scan CCD camera is useful to record electron diffraction intensities of glucose-embedded crotoxin complex crystal to 3 Å resolution. The quality of the electron diffraction intensities is high on the basis of the measured intensity equivalence ofthe Friedel-related reflections. Moreover, the number of patterns recorded from a single crystal can be as high as 120 under the constraints of radiation damage and electron statistics for the reflections in each pattern.A limitation of the slow-scan CCD camera for recording electron images of protein crystal arises from the relatively large pixel size, i.e. 24 μm (provided by Gatan). The modulation transfer function of our camera with a P43 scintillator has been determined for 400 keV electrons and shows an amplitude fall-off to 0.25 at 1/60 μm−1.

Misophonia: An Evidence-Based Case Report

2020 ◽  
Vol 29 (4) ◽  
pp. 685-690
Author(s):  
C. S. Vanaja ◽  
Miriam Soni Abigail
Keyword(s):  
Quality Of Life ◽  
Case Report ◽  
Case History ◽  
Pure Tone ◽  
Physiological Responses ◽  
Evidence Based ◽  
Management Option ◽  
Pure Tone Audiogram

Purpose Misophonia is a sound tolerance disorder condition in certain sounds that trigger intense emotional or physiological responses. While some persons may experience misophonia, a few patients suffer from misophonia. However, there is a dearth of literature on audiological assessment and management of persons with misophonia. The purpose of this report is to discuss the assessment of misophonia and highlight the management option that helped a patient with misophonia. Method A case study of a 26-year-old woman with the complaint of decreased tolerance to specific sounds affecting quality of life is reported. Audiological assessment differentiated misophonia from hyperacusis. Management included retraining counseling as well as desensitization and habituation therapy based on the principles described by P. J. Jastreboff and Jastreboff (2014). A misophonia questionnaire was administered at regular intervals to monitor the effectiveness of therapy. Results A detailed case history and audiological evaluations including pure-tone audiogram and Johnson Hyperacusis Index revealed the presence of misophonia. The patient benefitted from intervention, and the scores of the misophonia questionnaire indicated a decrease in the severity of the problem. Conclusions It is important to differentially diagnose misophonia and hyperacusis in persons with sound tolerance disorders. Retraining counseling as well as desensitization and habituation therapy can help patients who suffer from misophonia.

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