Effective Viscous Damping Enables Morphological Computation in Legged Locomotion

Muscle models and animal observations suggest that physical damping is beneficial for stabilization. Still, only a few implementations of mechanical damping exist in compliant robotic legged locomotion. It remains unclear how physical damping can be exploited for locomotion tasks, while its advantages as sensor-free, adaptive force- and negative work-producing actuators are promising. In a simplified numerical leg model, we studied the energy dissipation from viscous and Coulomb damping during vertical drops with ground-level perturbations. A parallel spring-damper is engaged between touch-down and mid-stance, and its damper auto-disengages during mid-stance and takeoff. Our simulations indicate that an adjustable and viscous damper is desired. In hardware we explored effective viscous damping and adjustability and quantified the dissipated energy. We tested two mechanical, leg-mounted damping mechanisms; a commercial hydraulic damper, and a custom-made pneumatic damper. The pneumatic damper exploits a rolling diaphragm with an adjustable orifice, minimizing Coulomb damping effects while permitting adjustable resistance. Experimental results show that the leg-mounted, hydraulic damper exhibits the most effective viscous damping. Adjusting the orifice setting did not result in substantial changes of dissipated energy per drop, unlike adjusting damping parameters in the numerical model. Consequently, we also emphasize the importance of characterizing physical dampers during real legged impacts to evaluate their effectiveness for compliant legged locomotion

DESIGN HARNESSING HOT SPRING’S ENERGY SYSTEM FOR COCOA BEANS DRYING

Geothermal energy is a one type source of alternative energy. Countries like United Stated, Australia, New Zealand, China, Canada and Turkey have used this energy for some applications such as for electricity generation, space and district heating, air conditioning, greenhouse heating and others. The presence of volcanoes, hot springs and other thermal phenomena lead people to explore and study energy produced inside earth. In Malaysia, there are also some places have the hot springs in Tambun, Sungkai, Pengkalan Hulu, Manong and others and currently use for recreation and tourism. For this project, the author wants to study and understanding this one type of alternative energy and design suitable system to harness hot spring’s energy and used for cocoa beans drying (industrial application). The problems that are being created from energy price hiking and our equator climate lead the author to find the solutions. The target is to design a suitable system which can harness hot spring’s energy and applied it on cocoa beans drying process. Since the energy is free and continuously produced inside the earth, the author wants to find the way how to commercial the energy. The important elements that need to be determine before starts the design is the behaviour of cocoa beans while drying and the unknowns related to the design that must being determine using the experiment and engineering calculations. The design must be in details for future works. This project can solve the problems of inconsistently weather condition and high price for fuel and gas that being used for artificial drying. This project also can make improvement with maximizing the quantity of the dried cocoa beans without affecting the quality

Pyrosequencing Evaluation of Widely Available Bisulfite Conversion Methods: Considerations for Application

Introduction: Bisulfite treatment of DNA introduces methylation-dependent sequence changes through selective chemical conversion of nonmethylated cytosine to uracil and serves as pretreatment step for the majority of DNA methylation analysis methods. Methods: We have evaluated the conversion performance of five of the most commonly used bisulfite treatment kits [MethylDetector (Active Motif), Epitect+ (Qiagen), Zymo Methylation, Zymo Gold and Zymo Lightning (all from Zymo Research)] by pyrosequencing four different regions with variable methylation levels, including: a repetitive element (ALUSX), a gene with low levels of methylation (IL6ST), an imprinted gene expected to be approximately 50% methylated (IGF2), and a fully methylated gene (ST3GAL2). In addition, we have studied the influence of duration (3 vs. 16 h) and type (fixed temperature vs. cycling program) of incubation protocol on the conversion efficiency of each evaluated kit. Results: All kits produced similar conversion rates of ALUSX, IGF2 and ST3GAL2, while the conversion of the low methylated IL6ST gene was variable between kits. The Zymo kits were highly consistent in their performance even when different protocols of incubation were applied, generating full conversion at the low methylated gene IL6; this was not true for the MethylDetector and Epitect+ kits. However, long-cycling incubation could produce similar conversion rates for the same locus in combination with Active Motif and Qiagen kits. Conclusions: The selection of a long-cycling protocol during conversion permits standardization of protocols, improving the reproducibility of methylation estimates across laboratories for gene-specific, genome-wide and bisulfite-based sequencing analyses

A Review of the Utilisation of Recycled Waste Material as an Alternative Modifier in Asphalt Mixtures

The possibility of using waste materials in road construction is of great interest as their utilisation may contribute to reducing the problems of hazard and pollution and conserve natural resources. Thus, there is an urgent need to find a sustainable method for using waste materials as a substitute in the standard asphalt binders. There are several concerns about the physical and chemical properties and mechanical performance of asphalt pavements incorporated with waste material in the effort to reduce permanent deformation of the road surface. This review article presents a brief discussion of the asphalt mixtures modified with waste material, and the recycled materials used as a modifier in the asphalt mixture. The present paper summarises the use of crumb rubber, crushed concrete, steel slag, glass fibre and plastic waste in asphalt mixtures. The use of waste materials as a modifier in asphalt mixture resulted in improved asphalt pavement performance. Results advocate that rubberised asphalt mixture with desired properties can be designed as an additive with a friendly environmental approach in construction materials. The researches that adopted the influence of usage, recycle waste material to improve the performance of the asphalt of the road are still limited compared to other construction fields. Doi: 10.28991/cej-2020-SP(EMCE)-05 Full Text: PD

DESIGN HARNESSING HOT SPRING’S ENERGY SYSTEM FOR COCOA BEANS DRYING

Geothermal energy is a one type source of alternative energy. Countries like United Stated, Australia, New Zealand, China, Canada and Turkey have used this energy for some applications such as for electricity generation, space and district heating, air conditioning, greenhouse heating and others. The presence of volcanoes, hot springs and other thermal phenomena lead people to explore and study energy produced inside earth. In Malaysia, there are also some places have the hot springs in Tambun, Sungkai, Pengkalan Hulu, Manong and others and currently use for recreation and tourism. For this project, the author wants to study and understanding this one type of alternative energy and design suitable system to harness hot spring’s energy and used for cocoa beans drying (industrial application). The problems that are being created from energy price hiking and our equator climate lead the author to find the solutions. The target is to design a suitable system which can harness hot spring’s energy and applied it on cocoa beans drying process. Since the energy is free and continuously produced inside the earth, the author wants to find the way how to commercial the energy. The important elements that need to be determine before starts the design is the behaviour of cocoa beans while drying and the unknowns related to the design that must being determine using the experiment and engineering calculations. The design must be in details for future works. This project can solve the problems of inconsistently weather condition and high price for fuel and gas that being used for artificial drying. This project also can make improvement with maximizing the quantity of the dried cocoa beans without affecting the quality

Is autonomic nervous system involved in restless legs syndrome during wakefulness?

OBJECTIVE: To investigate cardiovascular autonomic function in patients with restless leg syndrome (RLS) by means of cardiovascular reflexes and heart rate variability (HRV) during wakefulness.METHODS: Twelve RLS patients and 14 controls underwent cardiovascular function tests including head-up tilt test (HUTT), Valsalva maneuver, deep breathing, hand grip, and cold face. HRV analysis was performed in the frequency domain using both autoregressive (AR) and fast Fourier transform algorithms in rest supine condition and during HUTT.RESULTS: There was a significant increase in systolic blood pressure values in supine rest condition and a trend toward a lower Valsalva ratio in RLS patients with respect to controls. The significant and physiological changes of HRV at HUTT detected in healthy subjects were not found in RLS patients. CONCLUSION: RLS patients exhibit a tendency toward hypertension, reduced amplitude of both sympathetic and parasympathetic responses at HUTT, as well as blunted parasympathetic drive to blood pressure changes. These findings, if confirmed by more controlled studies, might support the hypothesis of auonomic nervous system involvement during wakefulness and consequently an enhanced cardiovascular risk in RLS

Muscle preflex response to perturbations in locomotion: In vitro experiments and simulations with realistic boundary conditions

Neuromuscular control loops feature substantial communication delays, but mammals run robustly even in the most adverse conditions. In vivo experiments and computer simulation results suggest that muscles’ preflex—an immediate mechanical response to a perturbation—could be the critical contributor. Muscle preflexes act within a few milliseconds, an order of magnitude faster than neural reflexes. Their short-lasting action makes mechanical preflexes hard to quantify in vivo. Muscle models, on the other hand, require further improvement of their prediction accuracy during the non-standard conditions of perturbed locomotion. Our study aims to quantify the mechanical work done by muscles during the preflex phase (preflex work) and test their mechanical force modulation. We performed in vitro experiments with biological muscle fibers under physiological boundary conditions, which we determined in computer simulations of perturbed hopping. Our findings show that muscles initially resist impacts with a stereotypical stiffness response—identified as short-range stiffness—regardless of the exact perturbation condition. We then observe a velocity adaptation to the force related to the amount of perturbation similar to a damping response. The main contributor to the preflex work modulation is not the change in force due to a change in fiber stretch velocity (fiber damping characteristics) but the change in magnitude of the stretch due to the leg dynamics in the perturbed conditions. Our results confirm previous findings that muscle stiffness is activity-dependent and show that also damping characteristics are activity-dependent. These results indicate that neural control could tune the preflex properties of muscles in expectation of ground conditions leading to previously inexplicable neuromuscular adaptation speeds