Computer Aided Electroforming for Rapid Manufacturing Applications

Author(s):  
Pedro M. Hernández Castellano ◽  
Ayoze Socas Sánchez ◽  
Antonio N. Benítez Vega ◽  
Mario Monzón Verona ◽  
Fernando Ortega García ◽  
...  

Electroforming enables the manufacture metallic parts with good mechanical properties and high level of accuracy and reproducibility. A thin metallic shell is deposited on a model and later released from it. There are several applications of electroforming combined with rapid manufacturing (RM) technologies. However the two main disadvantages of electroforming are the non-uniformity thickness distribution and long time span of shell manufacturing. The goal of this research is the evolution of Elecform3D™ product. It is a numerical simulation tool of electroforming process, in order to facilitate design and manufacturing tasks for metallic shells production. This software also controls the automatic device of cathodic orientation (ADCO) inside electrolytic baths. High quality of part is obtained, taking advantage of electroforming properties and improving manufacturing speed. The methodology is based on the well-known potentials model of LaPlace, it enables deposited metal distribution prediction with high grade of precision, being experimentally validated with cathodic polarization curves. Moreover this has also created a subroutine for solving this problem for this application using the boundary element method (BEM). This tool has been tested and validated for the simulation of metal electroplating by using reference solutions of problems in the literature. It also examines changes in the geometry of the cathode as a result of the process of electro-deposition of the metal and the influence of this phenomenon on the simulation routine developed considering variables such as the metal thickness distribution and the rate of deposition. All these tasks work and carry out processes complementing simulation with experimental work in the laboratory in order to create a tool that will give greater potential to this product. The results obtained with the first version of this product were very promising, and also indicated the need for a more precise analysis of electrochemical phenomena in the process of electroforming. Elecform3D™ is an important step beyond electroforming so far, and combined with additive manufacturing (AM) 3D printer, is a cheaper alternative for high quality metallic parts manufacturing in comparison with other RM technologies.

Author(s):  
Mario Monzo´n ◽  
Pedro M. Herna´ndez ◽  
Mari´a D. Marrero ◽  
Antonio N. Beni´tez ◽  
Fernando Ortega ◽  
...  

Electroforming enables metallic parts manufacturing with good mechanical properties and high level of accuracy and reproducibility. A thin metallic shell is deposited on a model and later released from it. There are several applications of electroforming combined with rapid prototyping: injection moulds, EDM electrodes, moulds for rotational moulding, complex metallic parts, etc. However the two main disadvantages of electroforming are the non uniform thicknesses distribution and high time of shell manufacturing. The paper focuses on a new development in order to achieve uniform thickness and otherwise a faster shell manufacturing. A new device and software have been developed, named Elecform3D™. The device is an automatic machine controlled by computer and assembled into the electroforming equipment. Otherwise the software not only controls the device but also simulates and calculates the optimal positions of the cathode based in the electrolytic parameters of the bath. The software recommends an automatic program of movements or allows the operator to decide another alternatives programs if necessary. Elecform 3D is an important step beyond electroforming so far. RP 3D printer combined with Elecform 3D is a cheaper alternative for high quality metallic parts manufacturing in comparison with SLS-SLM technologies or high speed machining, mainly for rapid tooling and even rapid manufacturing.


2007 ◽  
pp. 106-107
Author(s):  
B. K. Gannibal

Leonid Efimovich Rodin (1907-1990) was a graduate of Leningrad state University. To him, the future is known geobotanica, happened to a course in Botanical geography is still at the N. A. Bush. His teachers were also A. P. Shennikov and A. A. Korchagin, who subsequently headed related Department of geobotany and Botanical geography of Leningrad state University. This was the first school scientist. And since the beginning of the 30s of XX century and until the end of life L. E. was an employee of the Department of geobotany of the Komarov Botanical Institute (RAS), where long time worked together with E. M. Lavrenko, V. B. Sochava, B. A. Tikhomirov, V. D. Alexandrova and many other high-level professionals, first continuing to learn and gain experience, then defining the direction of development of geobotany in the Institute and the country as a whole.


2020 ◽  
Vol 11 (04) ◽  
pp. 640-642
Author(s):  
Halil Onder

AbstractGait disorders are common in the elderly as there are various causes of neurological and non-neurological conditions. On the other hand, most of the gait parameters do change with advancing age which is identified as age-related physiological changes in gait. At this point, the discrimination between age-related physiological changes and gait disorders may be strictly challenging. After identifying gait as an abnormal pattern, classification of it and making the responsible pathophysiology also require high-level expertise in this regard. Herein, we present a rare patient with corticobasal degeneration (CBD) who had admitted initially due to complaints of gait problems. Over a long time, the patient had received the misdiagnosis of gait abnormality due to musculoskeletal problems by multiple physicians. However, the detailed neurological exam showed a higher level gait disorder (HLGD). Further investigations at this point yielded the diagnosis of CBD.


Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 699
Author(s):  
Ruifeng Wang ◽  
Xiong Wu ◽  
Yanliang Zhai ◽  
Yuxuan Su ◽  
Chenhui Liu

Chengde City boasts a wealth of high-quality mineral water resources characterized by a high level of strontium (Sr), a low level of sodium, and low alkalinity. In order to study the mechanism of formation of Sr-bearing mineral water in Chengde and to scientifically guide future mineral water exploration, taking three typical mineral water exploration areas in Chengde as examples, this paper studies the sources of Sr in mineral water and the general rules of its dissolution via a laboratory static leaching experiment and impact experiments, and it provides an analysis of the characteristics of typical rock samples. The research results indicate that the content of Sr in surrounding rock and the characteristics of minerals existing in surrounding rock jointly control the dissolution of Sr in water; that CO2 can promote the formation of mineral water containing Sr; and that temperature increases may boost the dissolution of Sr from carbonate minerals but also inhibit the dissolution of Sr from silicate minerals.


2021 ◽  
pp. 1-7
Author(s):  
Natalie A. Chan ◽  
Zhisong Zhang ◽  
Guoxing Yin ◽  
Zhimeng Li ◽  
Roger C. Ho

SUMMARY Although hypnosis has played a part in psychotherapy for a long time, it is not yet seen as an evidence-based therapy and is absent from many practice guidelines when it comes to the treatment of psychiatric disorders. At present, the applications and methods of hypnotherapy are poorly understood and other methods of psychotherapy tend to be favoured. This review article aims to introduce the role of hypnotherapy and its application for certain common psychiatric presentations, as well as examine its efficacy by summarising recent evidence from high-quality outcome studies and meta-analyses.


2019 ◽  
Vol 4 (2) ◽  
pp. 89-101
Author(s):  
Samfriati S ◽  
Lilis N ◽  
Mercy N G

Academic procrastination is one of the postponement behaviors in lecture activities that are often found in students, in this study respondents experiencees a high level of procrastination that could hamper academic activities. One of the causes of procrastination is the use of gadgets that are too long to play games, music, entertainment and so on. Goals : The purpose of this study is to find out the relationship between the use of gadgets and academic procrastination onNursing Students level II Saint Elisabeth Medan 2019. Method : The study design is Cross Sectional. Total sampling technique sample are112 students. The measuring instrument used is a questionnaire. Result : The results shows that the majority of use of positive gadgets (92.9%) and moderate academic procrastination (63.4%). Based on the Fisher's Exact Test, it obtained p-value 0.026 (p <0.05), thus indicating a relationship between the use of gadgets and academic procrastination on nursing students level II STIKes Saint Elisabeth Medan. Conculsion: It is expected that respondents will be able to manage time well and not use gadgets for a long time for things that are not useful. Respondent s are expected to use gadgets for things that can support learning activities.


Author(s):  
Matiashuk R. ◽  
Tkachenko I.

The sensitivity of the reproductive structures of Forsythiasuspensato the complex influence of undifferentiated environmental factors has been studied.The monitoring sites are located in 15 different park ecosystems in 6 administrative districts of Kyiv. Data from the Borys Sreznevsky Central Geophysical Observatory (air pollution index (API) and meteorological conditions for 2018-2020) were used to assess the conditions of the growthenvironment. The influence of a complex of ecologically important factors during the flowering offorsythia on the quality of the formedpollen is noted. Thus, growing plantsfor a long time in conditions with a low level of air pollution (APIup to 5.0) in abnormal weather conditions in 2020,40-50% less fertile grainswere formed. And forplants, which grow in areas with increasedlevel (API5.0-7.0) and high level (API7.0-14.0) of air pollution, the share of fertile grains in the pollen population decreased by 60-80%. In the closed bud,the pollen has higher resistance to a complex of exogenous growth factors. Forsythia plants, which are located in large parklands, lose less pollen quality in adverse weather conditions and affected byurbotechnogenic factors. F. suspensa is an acceptable indicator of the level of environmental pollution by the deviation of pollen fertility from the control value. In areas with high aerogenic load, for example, areas with large highways (Bus Station «Darnytsia»), as well as with a significant recreational load (HolosiivskyiPark, Recreation Park on the Olena Teliha Street) much smaller pollen is formed. Itis noted that the conditions of forsythia growth affect the quantitative indicators of the formed pollen not only in the flower but also in the closed bud, which confirms the chronic effect of the complex of ingredients of aerotechnogenic emissions on plants of this species. The coefficient of sterility of pollen (CS) was used to objectively compare the data of 2019 and 2020 on the condition of the generative organs of F. suspensa in the studied areas. The calculation of the CS confirmed that in the closedbud pollen has a higher resistance to exogenous factors. In areas with high and increased levels of air pollution,during budding and flowering of plants (March-May,) there is a much higher CS of pollen of F. suspensа. Significant parkland territoriesof the city (for example, HolosiivskyiPark, Botanical Garden named after O. V. Fomin) provide less stressful conditions for growth and development of plants, even with the "very high" level of air pollution (ISA above 14.0) observed in April 2020 on this territory.The study of the susceptibility of F. suspensаpollen to growing conditions will be continued, as the prospects of using this species for bioindication of ecological status and zoning of park ecosystems of Kyiv according to the gradient of anthropogenic impact have been revealed.Key words:forsythia, fertility, coefficient of sterility of pollen, bioindication. Проведене дослідження чутливості репродуктивних структур Forsythiasuspensaдо комплексного впливу недиференційованих факторів навколишнього середовища. Моніторингові ділянки розташовані в 15 різних паркових екосистемах 6 адміністративних районівКиєва. Для оцінки умов середовища вирощування рослин використані дані Центральної геофізичної обсерваторії імені Бориса Срезневського (індекс забруднення атмосферного повітря (ІЗА) та метеорологічні умови за 2018-2020 рр.). Відмічено вплив комплексу екологічно важливих факторів (за показниками відхилення від норми середньої місячної температури повітря та місячної кількості опадів у Києві) уперіод квітування форзиції на якість сформованого пилку. Так, за тривалої експозиції рослин в умовах з низьким рівнем забруднення повітря (ІЗА до 5,0) в аномальних погодних умовах 2020 р. сформувалось на 40-50% менше фертильних зерен. А у форзиції, яка росте на територіях з підвищеним (ІЗА 5,0-7,0) та високим (ІЗА 7,0-14,0) рівнями забруднення частка фертильних зерен в популяції пилку зменшилась на 60-80%. У закритому бутоні пилок має вищу стійкість до комплексу екзогенних факторів середовища зростання. Рослини форзиції, які розташовані у значних за площею паркових насадженнях, менше втрачають якість пилку за несприятливих погодних умов та дії урботехногенних чинників. За відхиленням показника фертильності пилку від контрольного значення F. suspensaє допустимим індикатором рівня забруднення середовища. На територіях з підвищеним аерогенним навантаженням, наприклад, ділянки з автотранспортними магістралями (Автостанція «Дарниця»), а також зі значним рекреаційним навантаженням (Голосіївський парк імені М. Рильського, Парк відпочинку по вул. Олени Теліги)формується значно дрібніший пилок. Відмічено, що умови росту позначаються на кількісних показниках сформованого пилку не лише в квітці, але й в закритому бутоні, що підтверджує хронічний вплив комплексу інгредієнтів аеротехногенних викидів нарослини цього виду. Для об’єктивного співставлення даних 2019 і 2020 рр. щодо стану генеративних органів F. suspensaна досліджених ділянках був використаний коефіцієнт стерильності (КС) пилку. Розрахунок КС підтвердив, що в закритому бутоні пилок має вищу стійкість до впливу екзогенних чинників. Вищий КС був у F. suspense, з ділянок, на яких в період бутонізації і квітування рослин (березень-травень) відмічений високий і підвищений рівень забруднення атмосфери. Значні за площею паркові насадження міста (наприклад, Голосіївський парк, Ботанічний сад ім.акад. О.В. Фоміна) забезпечують менш напружені умови росту і розвитку рослин навіть при відміченому в квітні 2020 р. «дуже високому» рівні забруднення повітря (ІЗА вище 14,0) на цих територіях. Дослідження чутливості пилку F. suspenseдо умов вирощування буде продовжене,оскільки виявлена перспективність використання цього виду для біоіндикації екологічного стану та зонування паркових екосистем Києва за градієнтом антропогенного впливу.Ключові слова: форзиція, фертильність, індекс стерильності, біоіндикація.


2018 ◽  
Vol 49 ◽  
pp. 00044 ◽  
Author(s):  
Slawomir Gulkowski ◽  
Natalia Zytkowska ◽  
Piotr Dragan

Photovoltaic systems are designed to operate for a very long time according to the modules’ warranty that guarantees at least of 80% of the nominal power production after 20 years of use. In order to assure the continuous power production with a high level for a long time, thermographic analysis should be performed to detect incipient anomalies in individual modules and junction boxes. This safe, convenient and noncontact method allows carrying out the inspection for working system without any contact with live wiring and without disconnecting the PV systems. Temperature distribution of the module surface can reveal many different types of anomalies, i.e. hot spots caused by local shading, microcracking or cell breakage. This paper shows the results of the infrared thermography analysis of the operating PV systems consisting of different technological modules: polycrystalline silicon (pc-Si), copper indium gallium diselenide (CIGS) and cadmium telluride (CdTe). The average working temperature of each different kind of technological module as well as overheated areas were investigated in this study. Temperature of the MC4 connectors was also analysed.


2011 ◽  
Vol 2 (3) ◽  
pp. 59
Author(s):  
Germán Arroyo ◽  
Domingo Martín ◽  
María Victoria Luzón
Keyword(s):  

<p>Hand-made stippling has been used frequently in the process of drawing illustrations for documenting archaeological pieces. This is due to the fact that this technique represents in an efficient way shapes, tones, and textures, by means of distributing dots on the paper. The process of stippling has needed traditionally the ability of an artist, who usually produces the illustration from photographs. In this paper, a program that generates stippling illustrations of high quality is presented. The developed interface makes possible that any user can generate illustrations without the need of artistic abilities. The program is able to work in realtime, allowing the user interacts with the program. We have developed several artistic techniques in high level tasks that allow to improve the final results.</p>


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