scholarly journals Experimental CanSat Platform for Functional Verification of Burn Wire Triggering-Based Holding and Release Mechanisms

Aerospace ◽  
2021 ◽  
Vol 8 (7) ◽  
pp. 192
Author(s):  
Shankar Bhattarai ◽  
Ji-Seong Go ◽  
Hyun-Ung Oh
Keyword(s):  
Functional Performance ◽  
Flight Test ◽  
Easy Access ◽  
Functional Verification ◽  
Release Mechanism ◽  
Space Technology ◽  
Solar Panels ◽  
Distinctive Features ◽  
Release Mechanisms ◽  
Design Effectiveness

In this study, we present the Diverse Holding and Release Mechanism Can Satellite (DHRM CanSat) platform developed by the Space Technology Synthesis Laboratory (STSL) at Chosun University, South Korea. This platform focuses on several types of holding and release mechanisms (HRMs) for application in deployable appendages of nanosatellites. The objectives of the DHRM CanSat mission are to demonstrate the design effectiveness and functionality of the three newly proposed HRMs based on the burn wire triggering method, i.e., the pogo pin-type HRM, separation nut-type HRM, and Velcro tape-type HRM, which were implemented on deployable dummy solar panels of the CanSat. The proposed mechanisms have many advantages, including a high holding capability, simultaneous constraints in multi-plane directions, and simplicity of handling. Additionally, each mechanism has distinctive features, such as spring-loaded pins to initiate deployment, a plate with a thread as a nut for a high holding capability, and a hook and loop fastener for easy access to subsystems of the satellite without releasing the holding constraint. The design effectiveness and functional performance of the proposed mechanisms were demonstrated through an actual flight test of the DHRM CanSat launched by a model rocket.

Functional verification and performance tests of an ultra-low shock non-explosive actuator for hold-down and release mechanisms for space applications

2014 ◽  
Vol 228 (13) ◽  
pp. 2487-2495 ◽  
Author(s):  
OMF Morais ◽  
CMA Vasques ◽  
C Perestrelo ◽  
V Pimenta ◽  
G Baldesi
Keyword(s):  
Functional Performance ◽  
Release Time ◽  
Functional Verification ◽  
Engineering Model ◽  
Qualification Test ◽  
Space Applications ◽  
Ground Support ◽  
Release Mechanisms ◽  
Environmental Requirements ◽  
And Performance

This paper addresses the functional verification and performance assessment of an ultra-low shock non-explosive actuator appropriate to space applications of hold-down and release mechanisms. To demonstrate that the design implementation and manufacturing methods have resulted in an engineering model conforming to the set of functional, performance and environmental requirements specified, a space qualification test campaign is typically required. To ensure the readiness of the engineering model and the adequacy of the mechanical and electrical ground support equipment required for the entire qualification test campaign, a set of functional verification procedures and performance characterization tests were systematized and undertaken before the mechanism qualification. A preload monitoring system was developed and calibrated, and the performance of the mechanism was evaluated through the estimation of the release time and the measurement of the self-generated shock. The main results and conclusions taken from these tests are presented and discussed here.

scholarly journals Development of a Novel Deployable Solar Panel and Mechanism for 6U CubeSat of STEP Cube Lab-II

Aerospace ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 64
Author(s):  
Shankar Bhattarai ◽  
Ji-Seong Go ◽  
Hongrae Kim ◽  
Hyun-Ung Oh
Keyword(s):  
Solar Cells ◽  
Printed Circuit Board ◽  
Solar Panel ◽  
Circuit Board ◽  
Structural Safety ◽  
Release Mechanism ◽  
Constrained Layer Damping ◽  
Solar Panels ◽  
Printed Circuit ◽  
Design Effectiveness

The structural safety of solar cells mounted on deployable solar panels in the launch vibration environment is a significant aspect of a successful CubeSat mission. This paper presents a novel highly damped deployable solar panel module that is effective in ensuring structural protection of solar cells under the launch environment by rapidly suppressing the vibrations transmitting through the solar panel by constrained layer damping achieved using printed circuit board (PCB)-based multilayered thin stiffeners with double-sided viscoelastic tapes. A high-damping solar panel demonstration model with a three-pogo pin-based burn wire release mechanism was fabricated and tested for application in the 6U CubeSat “STEP Cube Lab-II” developed by Chosun University, South Korea. The reliable release function and radiation hardness assurance of the mechanism in an in-orbit environment were confirmed by performing solar panel deployment tests and radiation tests, respectively. The design effectiveness and structural safety of the proposed solar panel module were validated by launch vibration and in-orbit environment tests at the qualification level.

scholarly journals INFLUENCE OF FREE-FLOW EXCIPIENTS ON FUNCTIONAL PERFORMANCE OF NOVEONAA1 IN CONTROLLED-RELEASE TABLETS

2016 ◽  
Vol 8 (9) ◽  
pp. 6
Author(s):  
RubÉn Ramos Islas ◽  
Leopoldo Villafuerte Robles
Keyword(s):  
Drug Release ◽  
High Speed ◽  
Functional Performance ◽  
Release Profile ◽  
Free Flow ◽  
Release Mechanism ◽  
Powder Flowability ◽  
Powder Flow Rate ◽  
Controlled Release Tablets ◽  
Better Than

<p><strong>Objective: </strong>The aim of this work is the assessment of an eventual improvement in flowability of free flowing excipients on formulations containing Noveon AA1 and their influence on compactibility and release profile.</p><p><strong>Methods: </strong>Mixtures containing 20% Noveon AA1 and variable proportions of metronidazole and the free flowing excipients Prosolv EasyTab and GalenIQ 720 and 721were tested in their powder flow rate and the tablets compactibility and released profiles.</p><p><strong>Results: </strong>The powder flowability obtained with GalenIQ is about 20% better than that obtained with EasyTab. However, it is lesser than that considered as acceptable for a high-speed tableting machine. EasyTab reduces the drug release up to a half along with a continuing flattening of the release profile. This is attributed to an increasing tortuosity of the drug release path as the proportion EasyTab increases. GalenIQ restricts drug release in about a third with a lesser change in the release mechanism. This is attributed to competition for the available water inside the tablet, between the hydrating Noveon AA1 and the dissolving GalenIQ. The compactibility of the metronidazole/Noveon AA1 mixtures increases after addition of EasyTab in about 3.5 N per unit percentage of the added excipient while GalenIQ does it in about 2.6 N.</p><p><strong>Conclusion: </strong>The powder flowability of mixtures of metronidazole with Noveon AA1 was not suited for direct compression after addition of 40% of the free-flow excipient. The free-flow excipients reduce the metronidazole release rate and increase its compactibility. It was not observed a different clear functioning between both types of GalenIQ.</p>

Functional Verification of Nylon Wire Cutting-Type Holding & Release Mechanism for 6U CubeSat"s Solar Panel

2018 ◽  
Vol 46 (10) ◽  
pp. 867-875
Author(s):  
Yeon-Hyeok Park ◽  
Ji-Seong Go ◽  
Bong-Geon Chae ◽  
Seong-Ho Lee ◽  
Hyun-Ung Oh
Keyword(s):  
Solar Panel ◽  
Functional Verification ◽  
Release Mechanism ◽  
Wire Cutting

scholarly journals Experimental Validation of a Highly Damped Deployable Solar Panel Module with a Pogo Pin-Based Burn Wire Triggering Release Mechanism

2020 ◽  
Vol 2020 ◽  
pp. 1-14 ◽  
Author(s):  
Shankar Bhattarai ◽  
Ji-Seong Go ◽  
Hongrae Kim ◽  
Hyun-Ung Oh
Keyword(s):  
Room Temperature ◽  
Experimental Validation ◽  
Solar Panel ◽  
Structural Safety ◽  
Release Mechanism ◽  
Thermal Vacuum ◽  
Triggering Mechanism ◽  
Damping Characteristics ◽  
Ambient Room Temperature ◽  
Design Effectiveness

In this present work, a highly damped deployable solar panel module was developed for application in the 3 U CubeSat. The solar panel proposed herein is effective in guaranteeing the structural safety of solar cells under a launch environment owing to the superior damping characteristics achieved using multilayered stiffeners with viscoelastic acrylic tapes. A holding and release action of the solar panel was achieved by a new version of spring-loaded pogo pin-based burn wire triggering mechanism. A demonstration model of high-damping solar panel assembly was fabricated and tested to validate the effectiveness of the design. The holding and release mechanism achieved using a pogo pin was functionally tested through solar panel deployment tests under ambient room temperature and a thermal vacuum environment. The design effectiveness and structural safety of the solar panel module were validated through qualification-level launch and in-orbit environment tests.

scholarly journals Heparan Sulfated Glypican-4 is Released from Astrocytes Predominantly by Proteolytic Shedding

2021 ◽  
Author(s):  
Kevin Huang ◽  
Sungjin Park
Keyword(s):  
Synapse Formation ◽  
Regulatory Mechanism ◽  
Active Form ◽  
Release Mechanism ◽  
Loss Of Function ◽  
Secreted Factors ◽  
Release Mechanisms ◽  
Synapse Maturation ◽  
And Function ◽  
Proteolytic Shedding

AbstractAstrocytes provide neurons with diffusible factors that promote synapse formation and maturation. In particular, glypican-4/GPC4 released from astrocytes promotes the maturation of excitatory synapses. Unlike other secreted factors, GPC4 contains the C-terminal GPI-anchorage signal. However, the mechanism by which membrane-tethered GPC4 is released from astrocytes is unknown. Using primary astrocyte cultures and a quantitative luciferase-based release assay, we show that GPC4 is expressed on the astrocyte surface exclusively via a GPI-anchorage. Soluble GPC4 is robustly released from the astrocytes predominantly by proteolytic shedding and, to a lesser extent, by GPI-anchor cleavage, but not by vesicular release. Pharmacological, overexpression, and loss of function screens showed that ADAM9 in part mediates the release of GPC4 from astrocytes. The released GPC4 contains the heparan sulfate side chain, suggesting that these release mechanisms provide the active form that promotes synapse maturation and function. Overall, our studies identified the release mechanisms and the major releasing enzyme of GPC4 in astrocytes and will provide insights into understanding how astrocytes regulate synapse formation and maturation.Significance StatementAstrocyte-derived diffusible factors regulate synapse development and function. However, the regulatory mechanism underlying the release of astrocyte-derived factors is poorly understood. Noting that, unlike many other secreted factors, glypican-4/GPC4 is GPI-anchored, we characterized the release mechanism of GPI-anchored GPC4 from astrocytes and identified the releasing enzyme. Heparan sulfated GPC4 is robustly released from the astrocytes predominantly by proteolytic shedding. In particular, ADAM9 in part mediates the release of GPC4 from astrocytes. Our study provides an enzymatic mechanism for releasing GPC4 from astrocytes and will provide a novel opportunity to understand the regulatory mechanism of neuron-glia communication for synaptogenesis.

A Look at the Future of Public Gardens

2020 ◽  
pp. 156-160
Author(s):  
Donald A. Rakow ◽  
Meghan Z. Gough ◽  
Sharon A. Lee
Keyword(s):  
In Situ Conservation ◽  
Ex Situ ◽  
Conservation Strategies ◽  
Easy Access ◽  
Solar Panels ◽  
Public Gardens ◽  
The Future ◽  
Public Garden ◽  
In The Wild ◽  
Or Gene

The final chapter provides a detailed analysis of strategies for successful partnerships and how they can be evaluated. It talks about the American Public Gardens Association's vision to make public gardens an indispensable part of communities. The APGA defines public gardens as institutions that maintain “collections of plants for the purposes of public education and enjoyment, in addition to research, conservation, and higher learning.” Gardens can best lead the way by establishing and demonstrating effective biodiversity conservation strategies in the midst of rapidly changing natural landscapes. One strategy is to preserve locally, regionally, or globally endangered species in their native habitats, which is known as in situ conservation. A second strategy is for public gardens to establish ex situ seed banks or gene banks at their sites that will preserve the genetic identities of species threatened or extirpated in the wild. Public gardens also need to be paragons of sustainable behavior, whether through LEED-certified buildings, SITES-approved landscapes, the use of solar panels and windmills, reduction or elimination of pesticides, or the use of electric vehicles. The public garden of the future will need to partner with architects, urban planners, and progressive corporations to produce a new generation of green buildings and urban gardens, so that cities will become centers of clean air and renewable energy and provide all their residents with easy access to nature.

Phases in the temporal multiscale evolution of the drug release mechanism in IPN-type chitosan based hydrogels

2014 ◽  
Vol 16 (47) ◽  
pp. 25896-25905 ◽  
Author(s):  
E. S. Bacaita ◽  
B. C. Ciobanu ◽  
M. Popa ◽  
M. Agop ◽  
J. Desbrieres
Keyword(s):  
Drug Release ◽  
Temporal Evolution ◽  
Release Mechanism ◽  
Drug Release Mechanism ◽  
Release Mechanisms

Different release mechanisms are identified in the temporal evolution of drug release from IPN-type hydrogels, conducted over longer timescales.

scholarly journals Nicotinate-adenine dinucleotide phosphate-induced Ca2+-release does not behave as a Ca2+-induced Ca2+-release system

1996 ◽  
Vol 316 (3) ◽  
pp. 709-711 ◽  
Author(s):  
Eduardo N. CHINI ◽  
Thomas P. DOUSA
Keyword(s):  
Sea Urchin ◽  
The Other ◽  
Release Mechanism ◽  
Inositol 1 ◽  
Release System ◽  
Release Mechanisms ◽  
Sea Urchin Egg ◽  
Wide Range ◽  
Cyclic Adp Ribose ◽  
Regulatory Impact

We investigated the dependence of nicotinate–adenine dinucleotide phosphate (NAADP)-induced Ca2+ release from intracellular stores of sea urchin egg homogenates, upon extravesicular Ca2+. In contrast to the Ca2+ release induced by inositol 1´,4´,5´trisphosphate (IP3) or cyclic ADP-ribose (cADPR), the Ca2+ release induced by NAADP was completely independent of the free extravesicular Ca2+ over a wide range of concentrations (0–0.1 mM). The Ca2+ release triggered by either cADPR or IP3 was biphasically modulated by extravesicular Ca2+, and the Ca2+ release by these agents was abolished when the extravesicular Ca2+ was removed by chelation with 2 mM EGTA. On the other hand, NAADP-triggered Ca2+ release was not influenced by EGTA. These data indicate that while both cADPR and IP3 systems behave as functional Ca2+-induced Ca2+ release mechanisms, NAADP activates a Ca2+ release mechanism which is independent of the presence of extravesicular Ca2+. Therefore, the NAADP-sensitive Ca2+ release mechanisms may have a unique regulatory impact upon intracellular Ca2+ homoeostasis.

Evaluating Drone Tension Release-Mechanisms for Consistency

2020 ◽  
Vol 17 (11) ◽  
pp. 5130-5135
Author(s):  
Pierre E. Hertzog ◽  
Arthur James Swart
Keyword(s):  
Quantitative Data ◽  
Release Mechanism ◽  
Maximum Deviation ◽  
Decision Making Process ◽  
Weight Class ◽  
Specific Location ◽  
Average Value ◽  
Release Mechanisms ◽  
Operating Limits ◽  
Specific Technology

Monitoring of any kind requires consistency. Reliable and repeatable data must be obtained so as to ensure that any decision making process is well informed so as to prevent serious damage, loss or injury. Monitoring may also be used for quality assurance, where a specific technology is tested repeatedly to determine if its performance remains consistent. The purpose of this paper builds on previous work by an innovative jig to evaluate a number of tension release-mechanisms from a variety of manufacturers in order to determine their operating limits and their subsequent degree of consistency in performance. These tension release mechanisms are primarily used in fishing, where fishing bait attached to a fish line needs to be dropped at a specific location in the sea. An experimental study is conducted where quantitative data is collected of seven such mechanisms obtained from different manufacturers. Each mechanism was tested 10 times with a given weight. Averages values are then calculated that relates to the required weight needed to activate the tension release-mechanism. A maximum deviation percentage from this average value is then calculated. The Gannet range of mechanism performed the best, with accuracy levels above 95%. The worst performing mechanisms ranged in accuracy levels from 13.9% to 42%. Results do seem to indicate that a thicker fishing line with a heavier weight brings out the best performance in all the release-mechanisms, as the level of accuracy increases for each increase in weight class. Consumers, or end-users, can make use of this information to select an appropriate release-mechanism that will satisfy their requirements for such a mechanism, be it casual or professional fishing.

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