scholarly journals Analysis of linkage type sea wave power plant design through motion study and 3D printed modelling

2021 ◽  
Vol 926 (1) ◽  
pp. 012011
Author(s):  
R P Prayitnoadi ◽  
B S Wibowo ◽  
A Pamungkas ◽  
A Islamiyah ◽  
M Lestari ◽  
...  
Keyword(s):  
Energy Generation ◽  
Ocean Waves ◽  
Plant Design ◽  
Linkage Mechanism ◽  
Original Design ◽  
Friction Forces ◽  
Motion Study ◽  
3D Printed ◽  
Current Energy ◽  
Made In

Abstract Sustainable energy generation is becoming increasingly important because of the expected limitations in current energy resources and for reducing pollution. Wave energy generation has seen significant developments in recent years. This research has produced a linkage-type PLTGL design that utilizes ocean waves to raise and lower the float lever and move the linkage mechanism which then causes a back and forth movement of the rack gear which will rotate the pinion and cause the dynamo drive shaft to rotate. Using ocean wave data in the waters of Tanjung Berikat, Bangka Tengah, and with the help of the SolidWorks application, this design is then simulated to determine the resulting movement and rotation. The rotation generated through the simulation can reach 532 Rpm with the assumption that it does not involve friction forces and material loads that exist in the PLTGL design. This design was made in 3D using the CR-10 V3 type 3D printing machine which produced a model with a scale of 25% of the original design. The model is used as a discussion material for designers to improve the design.

scholarly journals The Recovery of Cu, Co, Zn, and Mn from a Complex Oxide Ore Using an Enhanced Reduction Leaching

Metals ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1636
Author(s):  
Sangyun Seo ◽  
Kyu Sung Han ◽  
Sung Il Lee ◽  
Myong Jun Kim
Keyword(s):  
Sulphuric Acid ◽  
Complex Oxide ◽  
Plant Design ◽  
Two Stage ◽  
Reduction Stage ◽  
Oxidation Reduction ◽  
Mineral Structure ◽  
Current Operation ◽  
Mn Oxides ◽  
Made In

The processing of Cu, Co, and Zn at the Boleo project in Mexico involves two-stage (oxidation–reduction) leaching to extract a total of 85–88% Cu in 4 h. The first stage is an oxidation leaching using sulphuric acid (120 kg/tonne ore) at an Eh of 900 mV for 2 h. Then, the reduction stage takes place in 2 h with SO2 gas sparging for Mn and Co extraction at an Eh of 350–370 mV. The final extraction rates of metal values are 92% of Mn, 80% of Co, and 60% of Co, respectively, after 4 h of leaching at 70 °C. However, the same metal recoveries were obtained within 2 h using an equal amount of sulphuric acid and the addition of 25 kg of SO2 per tonne of ore in a single stage leaching in this research. In this case, the Fe extracted from the ore as Fe2+/Fe3+ is believed to have acted as an electrochemical couple contiguously leaching the Cu sulphide and Mn oxides, which also increased the Cu recovery as the Cu mineralised mostly intergrowths in these mineral structure matrices. A significant improvement was made in which the leaching time was halved to 2 h compared to 4 h in the previous plant design and current operation, involving the two-stage oxidation–reduction leaching.

Calculating Thermal Gradients in a B31.1 Welding End Transition Joint by Formulae

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
David H. Creates
Keyword(s):  
Power Plant ◽  
Computer Program ◽  
Fatigue Damage ◽  
Power Plants ◽  
Life Extension ◽  
Thermal Gradients ◽  
Plant Design ◽  
Original Design ◽  
Plant Life ◽  
Fatigue Evaluation

Fatigue evaluation in B31.1 is currently done based on equations 1 and 2 of ASME B31.1-2007 Power Piping, which only considers the displacement load ranges. However, fatigue damage, in addition to displacement load ranges, is occurring in B31.1 piping due to pressure cycling and thermal gradients. To exacerbate this, power plant design pressures and temperatures are rising, new materials are being introduced, pipes and attached components are becoming increasingly thick, and owners are requiring power plants to heat-up and cool-down at faster rates. Also, power plant owners are more and more interested in extending the life of power plants beyond their original design life. This article takes the first step in addressing the pressing need to address this additional fatigue damage by quantifying thermal gradients in the prevalent B31.1 welding end transitions in Fig. 127.4.2, or tapered transition joints (TTJs) in Appendix D, of ASME B31.1-2007 Power Piping by formulae to be able to evaluate their contribution to fatigue (see PVP2009-77148 [A Procedure to Evaluate a B31.1 Welding End Transition Joint to Include the Fatigue Effects of Thermal Gradients for Design and Plant Life Extension]). The disadvantage of this approach is that the conservatisms inherent in the calculations of thermal gradients, as per ASME Section III Subsection NB3600-2007, are also inherent in these calculations and may produce unacceptable results when evaluated as per PVP2009-77148 [A Procedure to Evaluate a B31.1 Welding End Transition Joint to Include the Fatigue Effects of Thermal Gradients for Design and Plant Life Extension]. If the results are unacceptable, it is a warning that something else needs to be done. The advantage of this approach is that it eliminates the need for a computer program to quantify these thermal gradients, a computer program that is not normally accessible to the B31.1 designer anyway. Instead, the formulae use the data that are available to the B31.1 designer, namely, physical geometry, thermal conductivity, and rate of temperature change in the fluid in the pipe. This will further help to preserve the integrity of the piping pressure boundary and, consequently, the safety of personnel in today’s power plants and into the future.

3D Printing for Manufacturing Antique and Modern Musical Instrument Parts

2016 ◽  
Author(s):  
Frank Celentano ◽  
Nicholas May ◽  
Edward Simoneau ◽  
Richard DiPasquale ◽  
Zahra Shahbazi ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
Cloud Model ◽  
Low Cost ◽  
Sound Quality ◽  
Musical Instrument ◽  
Original Design ◽  
Manufacturing Method ◽  
3D Print ◽  
3D Printed

Professional musicians today often invest in obtaining antique or vintage instruments. These pieces can be used as collector items or more practically, as performance instruments to give a unique sound of a past music era. Unfortunately, these relics are rare, fragile, and particularly expensive to obtain for a modern day musician. The opportunity to reproduce the sound of an antique instrument through the use of additive manufacturing (3D printing) can make this desired product significantly more affordable. 3D printing allows for duplication of unique parts in a low cost and environmentally friendly method, due to its minimal material waste. Additionally, it allows complex geometries to be created without the limitations of other manufacturing techniques. This study focuses on the primary differences, particularly sound quality and comfort, between saxophone mouthpieces that have been 3D printed and those produced by more traditional methods. Saxophone mouthpieces are commonly derived from a milled blank of either hard rubber, ebonite or brass. Although 3D printers can produce a design with the same or similar materials, they are typically created in a layered pattern. This can potentially affect the porosity and surface of a mouthpiece, ultimately affecting player comfort and sound quality. To evaluate this, acoustic tests will be performed. This will involve both traditionally manufactured mouthpieces and 3D prints of the same geometry created from x-ray scans obtained using a ZEISS Xradia Versa 510. The scans are two dimensional images which go through processes of reconstruction and segmentation, which is the process of assigning material to voxels. The result is a point cloud model, which can be used for 3D printing. High quality audio recordings of each mouthpiece will be obtained and a sound analysis will be performed. The focus of this analysis is to determine what qualities of the sound are changed by the manufacturing method and how true the sound of a 3D printed mouthpiece is to its milled counterpart. Additive manufacturing can lead to more inconsistent products of the original design due to the accuracy, repeatability and resolution of the printer, as well as the layer thickness. In order for additive manufacturing to be a common practice of mouthpiece manufacturing, the printer quality must be tested for its precision to an original model. The quality of a 3D print can also have effects on the comfort of the player. Lower quality 3D prints have an inherent roughness which can cause discomfort and difficulty for the musician. This research will determine the effects of manufacturing method on the sound quality and overall comfort of a mouthpiece. In addition, we will evaluate the validity of additive manufacturing as a method of producing mouthpieces.

scholarly journals Polyjet 3D printing of tissue-mimicking materials: how well can 3D printed synthetic myocardium replicate mechanical properties of organic myocardium?

2019 ◽  
Author(s):  
Leah Severseike ◽  
Vania Lee ◽  
Taycia Brandon ◽  
Chris Bakken ◽  
Varun Bhatia
Keyword(s):  
Mechanical Properties ◽  
Biological Tissue ◽  
Mechanical Response ◽  
Axial Loading ◽  
Stress Concentrations ◽  
Friction Forces ◽  
Compliance Testing ◽  
3D Printed ◽  
Printed Materials ◽  
Digital Anatomy

AbstractAnatomical 3-D printing has potential for many uses in education, research and development, implant training, and procedure planning. Conventionally, the material properties of 3D printed anatomical models have often been similar only in form and not in mechanical response compared to biological tissue. The new Digital Anatomy material from Stratasys utilizes composite printed materials to more closely mimic the mechanical properties of tissue. Work was done to evaluate Digital Anatomy myocardium under axial loading for comparison with porcine myocardium regarding puncture, compliance, suturing, and cutting performance.In general, the Digital Anatomy myocardium showed promising comparisons to porcine myocardium. For compliance testing, the Digital Anatomy was either within the same range as the porcine myocardium or stiffer. Specifically, for use conditions involving higher stress concentrations or smaller displacements, Digital Anatomy was stiffer. Digital Anatomy did not perform as strongly as porcine myocardium when evaluating suture and cutting properties. The suture tore through the printed material more easily and had higher friction forces both during needle insertion and cutting. Despite these differences, the new Digital Anatomy myocardium material was much closer to the compliance of real tissue than other 3D printed materials. Furthermore, unlike biological tissue, Digital Anatomy provided repeatability of results. For tests such as cyclic compression, the material showed less than two percent variation in results between trials and between parts, resulting in lower variability than tissue. Despite some limitations, the myocardium Digital Anatomy material can be used to configure structures with similar mechanical properties to porcine myocardium in a repeatable manner, making this a valuable research tool.

Rapid Prototyping Technology for Special Pressure Vessels

2018 ◽  
Vol 919 ◽  
pp. 222-229
Author(s):  
Jiří Šafka ◽  
Filip Veselka ◽  
Martin Lachman ◽  
Michal Ackermann
Keyword(s):  
Additive Manufacturing ◽  
3D Printing ◽  
3D Model ◽  
Selective Laser Sintering ◽  
Pressure Vessels ◽  
Pressure Test ◽  
Polypropylene Material ◽  
3D Printed ◽  
Manufacturing Technologies ◽  
Made In

The article deals with the topic of 3D printing of pressure vessels and their testing. The main focus of the research was on a 3D model of the pressure vessel, which was originally designed for a student formula racing car project. The described virtual 3D model was designed with regard to 3D printing. The physical model was manufactured using several additive manufacturing technologies. The first technology was FDM using ULTEM 1010 material. The next technology was SLS (Selective Laser Sintering) using polyamide materials (PA3200GF and PA2220). The last technology was SLA (Stereolithography) using a polypropylene material (Durable). Experimental evaluation of the vessels was carried out by a pressure test, which verified the compactness of the 3D printed parts and their possible porosity. At the end of the article, a comparison of each printed model is made in terms of their final price and weight, together with pressure and thermal resistance.

A Procedure to Evaluate a B31.1 Welding End Transition Joint to Include the Fatigue Effects of Thermal Gradients for Design and Plant Life Extension

2009 ◽  
Author(s):  
David H. Creates
Keyword(s):  
Power Plant ◽  
Computer Program ◽  
Power Plants ◽  
Additional Term ◽  
Life Extension ◽  
Thermal Gradients ◽  
Plant Design ◽  
Original Design ◽  
Plant Environment ◽  
Fatigue Evaluation

Fatigue evaluation in B31.1 is currently done based on Equation 1 & 2 [B31.1-2007] which considers only displacement load ranges. Yet, fatigue damage is also occurring due to pressure cycling and thermal gradients. To exacerbate this, power plant design pressures and temperatures are rising, new materials are being introduced, pipes and attached components are become increasingly thick, and owners are requiring the power plants to heat-up and cool-down at faster rates. Also, power plant owners are more and more interested in extending the life of power plants beyond their original design life. Although the knowledge of thermal gradients has been available for many years, no attempt has been made to incorporate this into the B31.1 Code. This paper takes the first step in addressing this pressing need in today’s power plant environment. Granted there are several configurations where the effects of thermal gradients could be assessed. As the first step, this paper provides a procedure to evaluate the fatigue effects of thermal gradients in the prevalent Welding End Transition Joint (ASME B31.1 Fig 127.4.2) based on thermal gradients calculated as per [PVP2009-77147]. The disadvantage of this approach is that the conservatism in the calculation thermal gradients inherent in ASME Section III Sub-section NB-3600-2007 is inherent in these calculations as well, and may produce unacceptable results. If the results turn out to be unacceptable, it is a warning that something else needs to be done in the way of either monitoring or modifying or further evaluation. The advantage of this methodology is that it maintains the traditional B31.1 approach to fatigue by controlling SE with the same limit of SA except that there is now an additional term, f ‘, to account for the fatigue effects due to thermal gradients. In addition, it eliminates the need for a computer program to calculate this additional term, a computer program that is not normally accessible to the B31.1 designer anyway. Considering the fatigue effects of thermal gradients in this way will further help to preserve the integrity of the piping pressure boundary and consequently, the safety of personnel in today’s power plants and into the future.

Braucht Deutschland einen Kapazitätsmarkt für eine sichere Stromversorgung?

2013 ◽  
Vol 62 (3) ◽  
Author(s):  
Christoph Maurer
Keyword(s):  
Market Design ◽  
Future Market ◽  
Policy Debate ◽  
Political Debate ◽  
Security Of Supply ◽  
General Acceptance ◽  
Ecological Aspects ◽  
Sustainable Equilibrium ◽  
Current Energy ◽  
Made In

AbstractThe current political debate on the Energiewende in Germany is no longer focused on economic and ecological aspects. Instead, concerns regarding security of supply become more and more relevant. Though current risks for security of supply are mainly driven by the situation in transmission systems, policy debate is driven by the economic situation of plant operators and the provision of generation adequacy. On this background, many stakeholders claim the introduction of capacity mechanisms. The article shows that such decision should not be made in a purely national context, but requires strong European coordination. There is no clear evidence that the current energy-only market design will not deliver adequate investments in generation. However, a sustainable equilibrium requires stable and predictable boundary conditions for energy markets and a general acceptance of price peaks. A strategic reserve is proposed as an easy-to-implement, short-term and reversible means to guarantee security of supply while wellfounded political decisions on future market design can be taken.

Biological Treatment for Low-Activity Nuclear Wastewaters

1987 ◽  
Vol 19 (3-4) ◽  
pp. 345-353
Author(s):  
R. Ramadori ◽  
F. Fenoglio ◽  
L. Pozzi
Keyword(s):  
Wastewater Treatment ◽  
Organic Compound ◽  
Biological Treatment ◽  
Chemical Precipitation ◽  
Nuclear Industry ◽  
Plant Design ◽  
Liquid Wastes ◽  
Low Activity ◽  
Denitrification Process ◽  
Made In

Safety problems loom so large for the nuclear industry that provision must always be made in treatment of liquid wastes for their recycling to the production process. In this regard, a wastewater treatment consisting mainly of ammonia stripping, biological denitrification and chemical precipitation, looks very promising. With reference to the biological stage, this paper sets out the results of bench-scale tests performed to evaluate dimensioning parameters for the denitrification process. The tetrahydrofurfury1 alcohol, the major organic compound in the wastewater, was used as electron-donor substance. The procedure adopted for full-scale plant design and the preliminary results obtained using it, are also presented.

If Democracy Is Such a Smart Regime, Why Are Democracies Doing So Poorly at the Moment and How Can We Fix Them?

2021 ◽  
pp. 211-238
Author(s):  
Jason Brennan
Keyword(s):  
United States ◽  
Eighteenth Century ◽  
The United States ◽  
Selection Mechanism ◽  
New Paradigm ◽  
Original Design ◽  
The Core ◽  
Laws And Policies ◽  
The Moment ◽  
Made In

This chapter returns to the ideal of people’s power and argues that democracies as we know them are dubiously democratic. Most ordinary citizens, in the United States certainly but in other advanced democracies as well, have little deliberative input into the laws and policies that rule their lives. The chapter traces the problem to fundamental design mistakes made in the eighteenth century when elections, an oligarchic selection mechanism, rather than the traditional lot of Classical Athens, were privileged as the method for choosing representatives. This original design mistake explains in part why contemporary democracies are, and indeed have always been, dysfunctional. This chapter also makes the case for open democracy, a new paradigm of democracy that takes more seriously the core ideal of people’s power and in which elections are no longer a central institutional principle.

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