scholarly journals Caracterización de un músculo artificial de nylon y su implementación en una articulación de un robot manipulador serial

2019 ◽  
pp. 1-7
Author(s):  
Patricio Zamudio-Martínez ◽  
Alejandro Tonatiuh Aguilar-Salazar
Keyword(s):  
Ambient Temperature ◽  
Thermal Shock ◽  
Thermal Control ◽  
Soft Robotics ◽  
Thermal Stimulus ◽  
Slow Response ◽  
Intelligent Materials ◽  
Anisotropic Property ◽  
Thermal Stimuli

In this paper we present the study and description of a nylon muscle, to validate its performance and define its properties, applying loads on it and subjecting it to thermal stimuli. The results of the implementation of the nylon muscle are reported in a joint of a rigid mechanism, of a serial manipulator, however, the difficult thermal control that the muscle possesses makes the thermal shock (the ambient temperature and the applied one) wear at a certain point to the muscle, exhausting its properties or a very slow response from it. Testing that the material can only be used in the suspension of the load in the application of rigid systems. It is observed that an important feature of nylon muscles is their incredible capacity to contract loads that are higher than the same weight of the muscle and that by means of a thermal stimulus can be contracted thanks to its anisotropic property, just as the material is extremely attractive for the application of soft robotics and intelligent materials

scholarly journals Avaliação de Tratamentos de Superação de Dormência em Sementes do Delonix regia (Boger ex Hook.) Raf coletadas no Horto Florestal Tote Garcia, Cuiabá, Mato Grosso

2017 ◽  
Vol 21 (1) ◽  
pp. 48
Author(s):  
Ana Carolina Amorim Marques ◽  
Osvaldo Borges Pinto Junior ◽  
Vera Lucia Lopes Vieira
Keyword(s):  
Ambient Temperature ◽  
Thermal Shock ◽  
Environmental Conditions ◽  
Economic Value ◽  
Mato Grosso ◽  
Delonix Regia ◽  
Breaking Dormancy ◽  
Manual Counting ◽  
The Family ◽  
Temperature Water

A árvore Delonix regia (flamboyant) pertence à família Fabaceae, subfamília Caesalpinioideae, originário da ilha de Madagascar. Tem potencial valor econômico ornamental, pois se trata de uma espécie extremamente florífera e exuberante, indicada para programas de arborização, como parques, praças e jardins, sendo inadequada para ruas e avenidas, devido a suas raízes serem caracterizadas como superficiais. Essa espécie exótica, adaptada as condições ambientais de clima tropical, tem porte de 10 – 12m de altura, de tronco volumoso, espesso, com raízes tabulares. Por apresentar características de dormência tegumentar, este trabalho teve objetivo de avaliar alguns tratamentos para superação de dormência das sementes do Delonix regia. O experimento foi do tipo quantitativo, em que as sementes foram submetidas a três tratamentos e uma testemunha, em um total de 4 tratamentos, com 75 sementes cada. A emergência foi observada in locu, por meio de contagem manual. Os tratamentos utilizados foram: escarificação mecânica com lixa (n° 120); imersão em água em temperatura ambiente por 72 horas, choque térmico com imersão das sementes em água a 80 ºC por 05 min e a testemunha em que não houve nenhuma intervenção. Observou-se que a escarificação mecânica e o choque térmico proporcionaram os melhores resultados para superação de dormência das sementes do Delonix regia.Palavras-chave: Paisagismo. Dormência. Emergência.AbstractThe tree Delonix regia (flamboyant) belongs to the family Fabaceae, subfamily Caesalpinioideae, originally from the island of Madagascar. It has the potential ornamental economic value, because it is an extremely floriferous and exuberant species suitable for reforestations programs such as parks,and gardens, being inappropriate for streets and avenues, because its roots are characterized as superficial. This exotic species, adapted to the environmental conditions of tropical climate, reaches size of 10-12 m tall, large trunk, dense with tabular roots. It is renowned for being an extremely floriferous and exuberant species. By presenting cutaneous numbness characteristics, the objective of this study was to evaluate some treatments to overcome dormancy of seeds Delonix regia. The experiment was the quantitative type, in which the seeds were subjectedto three treatments and a control, a total of 4 treatments with 75 seeds each. The emergence was observed in locus through manual counting. The treatments were mechanical scarification with sandpaper (#120); immersion in ambient temperature water for 72 hours, thermal shock deep soaking the seeds in water at 80 °C for 5 minutes and the control, which had no intervention. It was observed that the mechanical scarification and thermal shock provided the best results for breaking dormancy of seeds Delonix regia.Keywords: Landscaping. Emergency Seedling. Dormancy

Tunable Triangular Cellular Structures by Pneumatic Control of Dual Channel Actuators

2017 ◽  
Author(s):  
Zhihao Yuan ◽  
Jaehyung Ju
Keyword(s):  
Fast Response ◽  
Local Deformation ◽  
Pattern Generation ◽  
Cellular Structures ◽  
Soft Robotics ◽  
Acoustic Metamaterials ◽  
Programmable Matter ◽  
Intelligent Materials ◽  
Pneumatic Actuators ◽  
Pneumatic Control

Programmable matter, a material whose properties can be programmed to achieve desired density with volume change, shapes or structural properties (stiffness, strength, Poisson’s ratio, etc.) upon command, is an important technology for intelligent materials. Recently emerging soft robotics-based pneumatic control can be potentially used for the design of programmable matter due to its several advantages — quick response for actuation, stiffening effect with internal air pressure, easy to manufacture, inexpensive materials, etc. The objective of this work is to construct programmable two-dimensional (2D) cellular structures with pneumatic actuators, investigating the effect of local deformation of the pneumatic actuators on the macroscopic pattern generation and mechanical properties of cellular structures. We synthesize 2D soft triangular structures with pneumatic actuators embedding dual air channels wrapped with fiber reinforcement. The local deformation modes provide different macroscopic deformations of cellular structures. We build an analytical model integrating the deformation of a single actuating member with nonlinear deformation of cellular structures. Finite element based simulations and experimental validation are followed. This study integrates soft robotics with cellular structures for intelligent materials design, expanding the design space of materials with programming. The fast response of the tunable soft cellular structures may be an ideal for the application of acoustic metamaterials with tunable band gaps.

scholarly journals Possible analgesic effect of vigabatrin in animal experimental chronic neuropathic pain

1999 ◽  
Vol 57 (4) ◽  
pp. 916-920 ◽  
Author(s):  
NILZA D. ALVES ◽  
CARLOS M. DE CASTRO-COSTA ◽  
ALBA M. DE CARVALHO ◽  
FRANKLIN J. C. SANTOS ◽  
DELANO G. SILVEIRA
Keyword(s):  
Neuropathic Pain ◽  
Analgesic Effect ◽  
Wistar Rats ◽  
Pharmacological Study ◽  
Thermal Stimulus ◽  
Chronic Neuropathic Pain ◽  
Pain Symptoms ◽  
The Right ◽  
Dose Dependent ◽  
Thermal Stimuli

Since anticonvulsants have been used for treating neuralgias, an interest has arisen to experimentally test vigabatrin for its gabaergic mechanism of action. For this, 41 Wistar rats were used, and in 25 of them a constrictive sciatic neuropathy was induced (Bennet & Xie model). For testing pain symptoms, spontaneous (scratching) and evoked behaviors to noxious (46o C) and non-noxious (40o C) thermal stimuli were quantified. Moreover, a comparative pharmacological study of vigabatrin with other analgesic anticonvulsant drugs was also performed. The results showed a possible dose-dependent analgesic effect of vigabatrin (gamma-vinyl-GABA) on experimental neuropathic pain, as shown by the significant (p<0.05) decreasing effect of vigabatrin on scratching and by its significant (p<0.05) increasing effect on the latency of the right hindpaw withdrawal of the animals to noxious thermal stimulus. This was corroborated by similar findings with analgesic anticonvulsants (carbamazepine, phenytoin and valproic acid). This possible and not yet described analgesic effect of vigabatrin seems not to be opioid mediated.

Semi-Open Thermal Protection Scheme of Electronics in Nuclear Rescue Robot

2016 ◽  
Vol 853 ◽  
pp. 405-409
Author(s):  
Ke Sun ◽  
Yan Long Han ◽  
Wei Ling Luan
Keyword(s):  
Ambient Temperature ◽  
Thermal Protection ◽  
Working Hours ◽  
Thermal Control ◽  
Air Cooling ◽  
Rescue Robot ◽  
Protection Scheme ◽  
Control Scheme ◽  
Thermal Management Of Electronics ◽  
Forced Air

Thermal management of electronics is quite important for safe operation of nuclear rescue robot. However, the ambient temperature of the nuclear robot in the site of nuclear accident will suffer an alternation between ordinary and elevated temperature. Traditional phase change material (PCM) based closed scheme for thermal protection is not suitable due to the capacity limitation of PCM. Open scheme with forced air cooling or water cooling is not acceptable either, because it cannot operate in high temperature. Therefore, a semi-open thermal control scheme is proposed by using silica aerogel for heat insulation, PCM for heat absorption, and Nickel-titanium alloy spring as temperature switch. An investigation on different ambient temperature, laying angle, melting point of PCM and heat power is conducted. The results showed that, compared with the PCM-based closed scheme, our design can provide 19.23% prolonged safe working hours, which can improve the reliability of electronic devices.

Hot–Cold Confusion: Inverse Thermal Sensation When Hot and Cold Stimuli Coexist in a Thermal Localization Task

Perception ◽  
2021 ◽  
pp. 030100662110040
Author(s):  
Keisuke Arai ◽  
Miki Matsumuro ◽  
Satoshi Hashiguchi ◽  
Fumihisa Shibata ◽  
Asako Kimura
Keyword(s):  
Thermal Sensation ◽  
Thermal Stimulus ◽  
Localization Task ◽  
Directional Bias ◽  
Cold Stimulus ◽  
Thermal Stimuli

We focused on the inverse thermal sensation caused by the presence of both hot and cold stimuli, which we named hot–cold confusion. Some researchers have shown that when participants touch a thermal stimulus simultaneously with two opposite thermal stimuli on both sides, the outer temperatures dominate the center temperature; for example, a hot stimulus between two cold stimuli is perceived as cold. However, there has not been sufficient research on the effect of the center stimulus on the outer stimuli. In the current study, we placed a participant’s forearm on an alignment where hot and cold stimuli were alternately placed in three locations and found that the participants sometimes selected the inverse thermal sensation of the presented surface not only at the center but also at the outer locations. Namely, opposite thermal stimuli applied at multiple locations affected each other, and the participants sometimes perceived the hot stimulus at the outer location as cold even when the two of three stimuli were hot, and vice versa. In addition, using various alignments of thermal stimuli, we revealed a directional bias of the effect from the cold stimulus and a difference in strength according to its location on the forearm.

scholarly journals Problems of the Starting and Operating of Hydraulic Components and Systems in Low Ambient Temperature (Part IV)

2017 ◽  
Vol 24 (3) ◽  
pp. 45-57 ◽  
Author(s):  
Ryszard Jasiński
Keyword(s):  
Computer Simulation ◽  
Numerical Calculation ◽  
Ambient Temperature ◽  
Thermal Shock ◽  
Simulation Method ◽  
Operational Conditions ◽  
Working Medium ◽  
Numerical Calculation Method ◽  
Spool Valve ◽  
Low Ambient Temperature

Abstract Designers of hydraulically driven machines and devices are obliged to ensure during design process their high service life with taking into account their operational conditions. Some of the machines may be started in low ambient temperature and even in thermal shock conditions (due to delivering hot working medium to cold components). In order to put such devices into operation appropriate investigations, including experimental ones - usually very expensive and time-consuming, are carried out. For this reason numerical calculations can be used to determine serviceability of a hydraulic component or system operating in thermal shock conditions. Application of numerical calculation methods is much less expensive in comparison to experimental ones. This paper presents a numerical calculation method which makes it possible to solve issues of heat exchange in elements of investigated hydraulic components by using finite elements method. For performing the simulations the following data are necessary: ambient temperature, oil temperature, heat transfer coefficient between oil and surfaces of elements, as well as areas of surfaces being in contact with oil. By means of computer simulation method values of clearance between cooperating elements as well as ranges of parameters of correct and incorrect operation of hydraulic components have been determined. In this paper results of computer simulation of some experimentally tested hydraulic components such as axial piston pump and proportional spool valve, are presented. The computer simulation results were compared with the experimental ones and high conformity was obtained.

Parameters Affecting the Kinetic Friction of Ice

1987 ◽  
Vol 109 (3) ◽  
pp. 552-559 ◽  
Author(s):  
M. Akkok ◽  
C. M. McC. Ettles ◽  
S. J. Calabrese
Keyword(s):  
Regression Analysis ◽  
Thermal Properties ◽  
Ambient Temperature ◽  
Control Mechanism ◽  
Theoretical Models ◽  
Thermal Control ◽  
Experimental Results ◽  
Analytical Models ◽  
Kinetic Friction ◽  
Ice Friction

A study of the mechanics of ice friction was performed in which various theoretical models were compared to experimental results. Analytical models indicate that ice friction is affected by load, speed, ambient temperature, and thermal properties of the counterface material. All four parameters were varied and the results compared to analytical models with additional study using regression analysis. Conclusions indicate that under some conditions the friction of ice is subject to a thermal control mechanism.

scholarly journals Problems of the starting and operating of hydraulic units and systems in low ambient temperature (Part I)

2008 ◽  
Vol 15 (4) ◽  
pp. 37-44 ◽  
Author(s):  
Ryszard Jasiński
Keyword(s):  
Ambient Temperature ◽  
Thermal Shock ◽  
Experimental Tests ◽  
Hot Working ◽  
Ambient Conditions ◽  
Safe Operation ◽  
University Of Technology ◽  
Working Medium ◽  
Low Ambient Temperature

Problems of the starting and operating of hydraulic units and systems in low ambient temperature (Part I) Severe winters and sweltering summers which more and more often occur nowadays are the reason why machinery designers face many difficulties when designing devices which will be serviceable in extreme ambient conditions. Hence, defining the principles and conditions of safe operation of hydraulically driven machines and devices is essential for their designers and operators. For this reasons the author did a series of tests of hydraulic component and systems in thermal shock conditions (cooled-down component were supplied with hot working medium). In such conditions, starting parameters of the selected hydraulic component and systems which secured safety of their operation were determined. The experimental tests were carried out in the laboratory of the Chair of Hydraulics and Pneumatics, Gdańsk University of Technology.

Case History Fitness-for-Service Assessment of Cyclic Catalytic Reformer Motor Operated Valves in the Petrochemical Industry

2011 ◽  
Author(s):  
Nick A. Carr ◽  
Kraig S. Shipley ◽  
David J. Dewees
Keyword(s):  
Ambient Temperature ◽  
Thermal Shock ◽  
Case History ◽  
Petrochemical Industry ◽  
Large Diameter ◽  
Catalyst Regeneration ◽  
Process Flow ◽  
Valve Body ◽  
Catalytic Reformer

Reactors of cyclic catalytic reformers require catalyst regeneration about every 7 days (∼50 cycles per year). To facilitate the in situ regeneration, large diameter motor operated valves (MOV) are used (typically Class 600 NPS 8 to NPS 16 API 600 gate block valves). Double block-n-bleed arrangements of the MOVs are used to assure isolation of the 350 psig 960°F process and regeneration media. The regeneration MOVs will be closed and in isolation for up to 4 days and can reach temperatures close to ambient depending on their distance from the process flow. Once the MOVs are swung open, the valve body quickly transitions from ambient temperature to 960°F over a matter of minutes. Such an extreme thermal shock has historically led to a number of cracks in the MOV valve bodies. With each unit having over 50 MOVs, it becomes expensive and time consuming to open every MOV at a scheduled turnaround, inspect, and repair any cracking noticed.

Light- and Magnetic-Responsive Synergy Controlled Reconfiguration of Polymer Nanocomposites with Shape Memory Assisted Self-Healing Performance for Soft Robotics

2021 ◽  
Author(s):  
Yi Chen ◽  
Xing Zhao ◽  
Yan Li ◽  
Zhao-Yuan Jin ◽  
Yi Yang ◽  
...  
Keyword(s):  
Shape Memory ◽  
Polymer Nanocomposites ◽  
Soft Robotics ◽  
Self Healing ◽  
Stimuli Responsive ◽  
Biomimetic Materials ◽  
Intelligent Materials

Stimuli-responsive intelligent biomimetic materials are promoting the development of soft robotics. Despite tremendous advances in stimuli-responsive intelligent materials, it is still a challenge to design facile methods to integrate multifunctional...

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